1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Nuvoton NPCM7xx I2C Controller driver
4 *
5 * Copyright (C) 2020 Nuvoton Technologies tali.perry@nuvoton.com
6 */
7#include <linux/bitfield.h>
8#include <linux/clk.h>
9#include <linux/debugfs.h>
10#include <linux/errno.h>
11#include <linux/i2c.h>
12#include <linux/interrupt.h>
13#include <linux/iopoll.h>
14#include <linux/irq.h>
15#include <linux/jiffies.h>
16#include <linux/kernel.h>
17#include <linux/mfd/syscon.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/platform_device.h>
21#include <linux/regmap.h>
22
23enum i2c_mode {
24	I2C_MASTER,
25	I2C_SLAVE,
26};
27
28/*
29 * External I2C Interface driver xfer indication values, which indicate status
30 * of the bus.
31 */
32enum i2c_state_ind {
33	I2C_NO_STATUS_IND = 0,
34	I2C_SLAVE_RCV_IND,
35	I2C_SLAVE_XMIT_IND,
36	I2C_SLAVE_XMIT_MISSING_DATA_IND,
37	I2C_SLAVE_RESTART_IND,
38	I2C_SLAVE_DONE_IND,
39	I2C_MASTER_DONE_IND,
40	I2C_NACK_IND,
41	I2C_BUS_ERR_IND,
42	I2C_WAKE_UP_IND,
43	I2C_BLOCK_BYTES_ERR_IND,
44	I2C_SLAVE_RCV_MISSING_DATA_IND,
45};
46
47/*
48 * Operation type values (used to define the operation currently running)
49 * module is interrupt driven, on each interrupt the current operation is
50 * checked to see if the module is currently reading or writing.
51 */
52enum i2c_oper {
53	I2C_NO_OPER = 0,
54	I2C_WRITE_OPER,
55	I2C_READ_OPER,
56};
57
58/* I2C Bank (module had 2 banks of registers) */
59enum i2c_bank {
60	I2C_BANK_0 = 0,
61	I2C_BANK_1,
62};
63
64/* Internal I2C states values (for the I2C module state machine). */
65enum i2c_state {
66	I2C_DISABLE = 0,
67	I2C_IDLE,
68	I2C_MASTER_START,
69	I2C_SLAVE_MATCH,
70	I2C_OPER_STARTED,
71	I2C_STOP_PENDING,
72};
73
74#if IS_ENABLED(CONFIG_I2C_SLAVE)
75/* Module supports setting multiple own slave addresses */
76enum i2c_addr {
77	I2C_SLAVE_ADDR1 = 0,
78	I2C_SLAVE_ADDR2,
79	I2C_SLAVE_ADDR3,
80	I2C_SLAVE_ADDR4,
81	I2C_SLAVE_ADDR5,
82	I2C_SLAVE_ADDR6,
83	I2C_SLAVE_ADDR7,
84	I2C_SLAVE_ADDR8,
85	I2C_SLAVE_ADDR9,
86	I2C_SLAVE_ADDR10,
87	I2C_GC_ADDR,
88	I2C_ARP_ADDR,
89};
90#endif
91
92/* init register and default value required to enable module */
93#define NPCM_I2CSEGCTL			0xE4
94
95/* Common regs */
96#define NPCM_I2CSDA			0x00
97#define NPCM_I2CST			0x02
98#define NPCM_I2CCST			0x04
99#define NPCM_I2CCTL1			0x06
100#define NPCM_I2CADDR1			0x08
101#define NPCM_I2CCTL2			0x0A
102#define NPCM_I2CADDR2			0x0C
103#define NPCM_I2CCTL3			0x0E
104#define NPCM_I2CCST2			0x18
105#define NPCM_I2CCST3			0x19
106#define I2C_VER				0x1F
107
108/* BANK 0 regs */
109#define NPCM_I2CADDR3			0x10
110#define NPCM_I2CADDR7			0x11
111#define NPCM_I2CADDR4			0x12
112#define NPCM_I2CADDR8			0x13
113#define NPCM_I2CADDR5			0x14
114#define NPCM_I2CADDR9			0x15
115#define NPCM_I2CADDR6			0x16
116#define NPCM_I2CADDR10			0x17
117#define NPCM_I2CCTL4			0x1A
118#define NPCM_I2CCTL5			0x1B
119#define NPCM_I2CSCLLT			0x1C /* SCL Low Time */
120#define NPCM_I2CFIF_CTL			0x1D /* FIFO Control */
121#define NPCM_I2CSCLHT			0x1E /* SCL High Time */
122
123/* BANK 1 regs */
124#define NPCM_I2CFIF_CTS			0x10 /* Both FIFOs Control and Status */
125#define NPCM_I2CTXF_CTL			0x12 /* Tx-FIFO Control */
126#define NPCM_I2CT_OUT			0x14 /* Bus T.O. */
127#define NPCM_I2CPEC			0x16 /* PEC Data */
128#define NPCM_I2CTXF_STS			0x1A /* Tx-FIFO Status */
129#define NPCM_I2CRXF_STS			0x1C /* Rx-FIFO Status */
130#define NPCM_I2CRXF_CTL			0x1E /* Rx-FIFO Control */
131
132#if IS_ENABLED(CONFIG_I2C_SLAVE)
133/*
134 * npcm_i2caddr array:
135 * The module supports having multiple own slave addresses.
136 * Since the addr regs are sprinkled all over the address space,
137 * use this array to get the address or each register.
138 */
139#define I2C_NUM_OWN_ADDR 2
140#define I2C_NUM_OWN_ADDR_SUPPORTED 2
141
142static const int npcm_i2caddr[I2C_NUM_OWN_ADDR] = {
143	NPCM_I2CADDR1, NPCM_I2CADDR2,
144};
145#endif
146
147/* NPCM_I2CST reg fields */
148#define NPCM_I2CST_XMIT			BIT(0)	/* Transmit mode */
149#define NPCM_I2CST_MASTER		BIT(1)	/* Master mode */
150#define NPCM_I2CST_NMATCH		BIT(2)	/* New match */
151#define NPCM_I2CST_STASTR		BIT(3)	/* Stall after start */
152#define NPCM_I2CST_NEGACK		BIT(4)	/* Negative ACK */
153#define NPCM_I2CST_BER			BIT(5)	/* Bus error */
154#define NPCM_I2CST_SDAST		BIT(6)	/* SDA status */
155#define NPCM_I2CST_SLVSTP		BIT(7)	/* Slave stop */
156
157/* NPCM_I2CCST reg fields */
158#define NPCM_I2CCST_BUSY		BIT(0)	/* Busy */
159#define NPCM_I2CCST_BB			BIT(1)	/* Bus busy */
160#define NPCM_I2CCST_MATCH		BIT(2)	/* Address match */
161#define NPCM_I2CCST_GCMATCH		BIT(3)	/* Global call match */
162#define NPCM_I2CCST_TSDA		BIT(4)	/* Test SDA line */
163#define NPCM_I2CCST_TGSCL		BIT(5)	/* Toggle SCL line */
164#define NPCM_I2CCST_MATCHAF		BIT(6)	/* Match address field */
165#define NPCM_I2CCST_ARPMATCH		BIT(7)	/* ARP address match */
166
167/* NPCM_I2CCTL1 reg fields */
168#define NPCM_I2CCTL1_START		BIT(0)	/* Generate start condition */
169#define NPCM_I2CCTL1_STOP		BIT(1)	/* Generate stop condition */
170#define NPCM_I2CCTL1_INTEN		BIT(2)	/* Interrupt enable */
171#define NPCM_I2CCTL1_EOBINTE		BIT(3)
172#define NPCM_I2CCTL1_ACK		BIT(4)
173#define NPCM_I2CCTL1_GCMEN		BIT(5)	/* Global call match enable */
174#define NPCM_I2CCTL1_NMINTE		BIT(6)	/* New match interrupt enable */
175#define NPCM_I2CCTL1_STASTRE		BIT(7)	/* Stall after start enable */
176
177/* RW1S fields (inside a RW reg): */
178#define NPCM_I2CCTL1_RWS   \
179	(NPCM_I2CCTL1_START | NPCM_I2CCTL1_STOP | NPCM_I2CCTL1_ACK)
180
181/* npcm_i2caddr reg fields */
182#define NPCM_I2CADDR_A			GENMASK(6, 0)	/* Address */
183#define NPCM_I2CADDR_SAEN		BIT(7)		/* Slave address enable */
184
185/* NPCM_I2CCTL2 reg fields */
186#define I2CCTL2_ENABLE			BIT(0)		/* Module enable */
187#define I2CCTL2_SCLFRQ6_0		GENMASK(7, 1)	/* Bits 0:6 of frequency divisor */
188
189/* NPCM_I2CCTL3 reg fields */
190#define I2CCTL3_SCLFRQ8_7		GENMASK(1, 0)	/* Bits 7:8 of frequency divisor */
191#define I2CCTL3_ARPMEN			BIT(2)	/* ARP match enable */
192#define I2CCTL3_IDL_START		BIT(3)
193#define I2CCTL3_400K_MODE		BIT(4)
194#define I2CCTL3_BNK_SEL			BIT(5)
195#define I2CCTL3_SDA_LVL			BIT(6)
196#define I2CCTL3_SCL_LVL			BIT(7)
197
198/* NPCM_I2CCST2 reg fields */
199#define NPCM_I2CCST2_MATCHA1F		BIT(0)
200#define NPCM_I2CCST2_MATCHA2F		BIT(1)
201#define NPCM_I2CCST2_MATCHA3F		BIT(2)
202#define NPCM_I2CCST2_MATCHA4F		BIT(3)
203#define NPCM_I2CCST2_MATCHA5F		BIT(4)
204#define NPCM_I2CCST2_MATCHA6F		BIT(5)
205#define NPCM_I2CCST2_MATCHA7F		BIT(5)
206#define NPCM_I2CCST2_INTSTS		BIT(7)
207
208/* NPCM_I2CCST3 reg fields */
209#define NPCM_I2CCST3_MATCHA8F		BIT(0)
210#define NPCM_I2CCST3_MATCHA9F		BIT(1)
211#define NPCM_I2CCST3_MATCHA10F		BIT(2)
212#define NPCM_I2CCST3_EO_BUSY		BIT(7)
213
214/* NPCM_I2CCTL4 reg fields */
215#define I2CCTL4_HLDT			GENMASK(5, 0)
216#define I2CCTL4_LVL_WE			BIT(7)
217
218/* NPCM_I2CCTL5 reg fields */
219#define I2CCTL5_DBNCT			GENMASK(3, 0)
220
221/* NPCM_I2CFIF_CTS reg fields */
222#define NPCM_I2CFIF_CTS_RXF_TXE		BIT(1)
223#define NPCM_I2CFIF_CTS_RFTE_IE		BIT(3)
224#define NPCM_I2CFIF_CTS_CLR_FIFO	BIT(6)
225#define NPCM_I2CFIF_CTS_SLVRSTR		BIT(7)
226
227/* NPCM_I2CTXF_CTL reg field */
228#define NPCM_I2CTXF_CTL_THR_TXIE	BIT(6)
229
230/* NPCM_I2CT_OUT reg fields */
231#define NPCM_I2CT_OUT_TO_CKDIV		GENMASK(5, 0)
232#define NPCM_I2CT_OUT_T_OUTIE		BIT(6)
233#define NPCM_I2CT_OUT_T_OUTST		BIT(7)
234
235/* NPCM_I2CTXF_STS reg fields */
236#define NPCM_I2CTXF_STS_TX_THST		BIT(6)
237
238/* NPCM_I2CRXF_STS reg fields */
239#define NPCM_I2CRXF_STS_RX_THST		BIT(6)
240
241/* NPCM_I2CFIF_CTL reg fields */
242#define NPCM_I2CFIF_CTL_FIFO_EN		BIT(4)
243
244/* NPCM_I2CRXF_CTL reg fields */
245#define NPCM_I2CRXF_CTL_THR_RXIE	BIT(6)
246
247#define MAX_I2C_HW_FIFO_SIZE		32
248
249/* I2C_VER reg fields */
250#define I2C_VER_VERSION			GENMASK(6, 0)
251#define I2C_VER_FIFO_EN			BIT(7)
252
253/* stall/stuck timeout in us */
254#define DEFAULT_STALL_COUNT		25
255
256/* SCLFRQ field position */
257#define SCLFRQ_0_TO_6			GENMASK(6, 0)
258#define SCLFRQ_7_TO_8			GENMASK(8, 7)
259
260/* supported clk settings. values in Hz. */
261#define I2C_FREQ_MIN_HZ			10000
262#define I2C_FREQ_MAX_HZ			I2C_MAX_FAST_MODE_PLUS_FREQ
263
264struct npcm_i2c_data {
265	u8 fifo_size;
266	u32 segctl_init_val;
267	u8 txf_sts_tx_bytes;
268	u8 rxf_sts_rx_bytes;
269	u8 rxf_ctl_last_pec;
270};
271
272static const struct npcm_i2c_data npxm7xx_i2c_data = {
273	.fifo_size = 16,
274	.segctl_init_val = 0x0333F000,
275	.txf_sts_tx_bytes = GENMASK(4, 0),
276	.rxf_sts_rx_bytes = GENMASK(4, 0),
277	.rxf_ctl_last_pec = BIT(5),
278};
279
280static const struct npcm_i2c_data npxm8xx_i2c_data = {
281	.fifo_size = 32,
282	.segctl_init_val = 0x9333F000,
283	.txf_sts_tx_bytes = GENMASK(5, 0),
284	.rxf_sts_rx_bytes = GENMASK(5, 0),
285	.rxf_ctl_last_pec = BIT(7),
286};
287
288/* Status of one I2C module */
289struct npcm_i2c {
290	struct i2c_adapter adap;
291	struct device *dev;
292	unsigned char __iomem *reg;
293	const struct npcm_i2c_data *data;
294	spinlock_t lock;   /* IRQ synchronization */
295	struct completion cmd_complete;
296	int cmd_err;
297	struct i2c_msg *msgs;
298	int msgs_num;
299	int num;
300	u32 apb_clk;
301	struct i2c_bus_recovery_info rinfo;
302	enum i2c_state state;
303	enum i2c_oper operation;
304	enum i2c_mode master_or_slave;
305	enum i2c_state_ind stop_ind;
306	u8 dest_addr;
307	u8 *rd_buf;
308	u16 rd_size;
309	u16 rd_ind;
310	u8 *wr_buf;
311	u16 wr_size;
312	u16 wr_ind;
313	bool fifo_use;
314	u16 PEC_mask; /* PEC bit mask per slave address */
315	bool PEC_use;
316	bool read_block_use;
317	unsigned long int_time_stamp;
318	unsigned long bus_freq; /* in Hz */
319#if IS_ENABLED(CONFIG_I2C_SLAVE)
320	u8 own_slave_addr;
321	struct i2c_client *slave;
322	int slv_rd_size;
323	int slv_rd_ind;
324	int slv_wr_size;
325	int slv_wr_ind;
326	u8 slv_rd_buf[MAX_I2C_HW_FIFO_SIZE];
327	u8 slv_wr_buf[MAX_I2C_HW_FIFO_SIZE];
328#endif
329	u64 ber_cnt;
330	u64 rec_succ_cnt;
331	u64 rec_fail_cnt;
332	u64 nack_cnt;
333	u64 timeout_cnt;
334	u64 tx_complete_cnt;
335};
336
337static inline void npcm_i2c_select_bank(struct npcm_i2c *bus,
338					enum i2c_bank bank)
339{
340	u8 i2cctl3 = ioread8(bus->reg + NPCM_I2CCTL3);
341
342	if (bank == I2C_BANK_0)
343		i2cctl3 = i2cctl3 & ~I2CCTL3_BNK_SEL;
344	else
345		i2cctl3 = i2cctl3 | I2CCTL3_BNK_SEL;
346	iowrite8(i2cctl3, bus->reg + NPCM_I2CCTL3);
347}
348
349static void npcm_i2c_init_params(struct npcm_i2c *bus)
350{
351	bus->stop_ind = I2C_NO_STATUS_IND;
352	bus->rd_size = 0;
353	bus->wr_size = 0;
354	bus->rd_ind = 0;
355	bus->wr_ind = 0;
356	bus->read_block_use = false;
357	bus->int_time_stamp = 0;
358	bus->PEC_use = false;
359	bus->PEC_mask = 0;
360#if IS_ENABLED(CONFIG_I2C_SLAVE)
361	if (bus->slave)
362		bus->master_or_slave = I2C_SLAVE;
363#endif
364}
365
366static inline void npcm_i2c_wr_byte(struct npcm_i2c *bus, u8 data)
367{
368	iowrite8(data, bus->reg + NPCM_I2CSDA);
369}
370
371static inline u8 npcm_i2c_rd_byte(struct npcm_i2c *bus)
372{
373	return ioread8(bus->reg + NPCM_I2CSDA);
374}
375
376static int npcm_i2c_get_SCL(struct i2c_adapter *_adap)
377{
378	struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
379
380	return !!(I2CCTL3_SCL_LVL & ioread8(bus->reg + NPCM_I2CCTL3));
381}
382
383static int npcm_i2c_get_SDA(struct i2c_adapter *_adap)
384{
385	struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
386
387	return !!(I2CCTL3_SDA_LVL & ioread8(bus->reg + NPCM_I2CCTL3));
388}
389
390static inline u16 npcm_i2c_get_index(struct npcm_i2c *bus)
391{
392	if (bus->operation == I2C_READ_OPER)
393		return bus->rd_ind;
394	if (bus->operation == I2C_WRITE_OPER)
395		return bus->wr_ind;
396	return 0;
397}
398
399/* quick protocol (just address) */
400static inline bool npcm_i2c_is_quick(struct npcm_i2c *bus)
401{
402	return bus->wr_size == 0 && bus->rd_size == 0;
403}
404
405static void npcm_i2c_disable(struct npcm_i2c *bus)
406{
407	u8 i2cctl2;
408
409#if IS_ENABLED(CONFIG_I2C_SLAVE)
410	int i;
411
412	/* Slave addresses removal */
413	for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OWN_ADDR_SUPPORTED; i++)
414		iowrite8(0, bus->reg + npcm_i2caddr[i]);
415
416#endif
417	/* Disable module */
418	i2cctl2 = ioread8(bus->reg + NPCM_I2CCTL2);
419	i2cctl2 = i2cctl2 & ~I2CCTL2_ENABLE;
420	iowrite8(i2cctl2, bus->reg + NPCM_I2CCTL2);
421
422	bus->state = I2C_DISABLE;
423}
424
425static void npcm_i2c_enable(struct npcm_i2c *bus)
426{
427	u8 i2cctl2 = ioread8(bus->reg + NPCM_I2CCTL2);
428
429	i2cctl2 = i2cctl2 | I2CCTL2_ENABLE;
430	iowrite8(i2cctl2, bus->reg + NPCM_I2CCTL2);
431	bus->state = I2C_IDLE;
432}
433
434/* enable\disable end of busy (EOB) interrupts */
435static inline void npcm_i2c_eob_int(struct npcm_i2c *bus, bool enable)
436{
437	u8 val;
438
439	/* Clear EO_BUSY pending bit: */
440	val = ioread8(bus->reg + NPCM_I2CCST3);
441	val = val | NPCM_I2CCST3_EO_BUSY;
442	iowrite8(val, bus->reg + NPCM_I2CCST3);
443
444	val = ioread8(bus->reg + NPCM_I2CCTL1);
445	val &= ~NPCM_I2CCTL1_RWS;
446	if (enable)
447		val |= NPCM_I2CCTL1_EOBINTE;
448	else
449		val &= ~NPCM_I2CCTL1_EOBINTE;
450	iowrite8(val, bus->reg + NPCM_I2CCTL1);
451}
452
453static inline bool npcm_i2c_tx_fifo_empty(struct npcm_i2c *bus)
454{
455	u8 tx_fifo_sts;
456
457	tx_fifo_sts = ioread8(bus->reg + NPCM_I2CTXF_STS);
458	/* check if TX FIFO is not empty */
459	if ((tx_fifo_sts & bus->data->txf_sts_tx_bytes) == 0)
460		return false;
461
462	/* check if TX FIFO status bit is set: */
463	return !!FIELD_GET(NPCM_I2CTXF_STS_TX_THST, tx_fifo_sts);
464}
465
466static inline bool npcm_i2c_rx_fifo_full(struct npcm_i2c *bus)
467{
468	u8 rx_fifo_sts;
469
470	rx_fifo_sts = ioread8(bus->reg + NPCM_I2CRXF_STS);
471	/* check if RX FIFO is not empty: */
472	if ((rx_fifo_sts & bus->data->rxf_sts_rx_bytes) == 0)
473		return false;
474
475	/* check if rx fifo full status is set: */
476	return !!FIELD_GET(NPCM_I2CRXF_STS_RX_THST, rx_fifo_sts);
477}
478
479static inline void npcm_i2c_clear_fifo_int(struct npcm_i2c *bus)
480{
481	u8 val;
482
483	val = ioread8(bus->reg + NPCM_I2CFIF_CTS);
484	val = (val & NPCM_I2CFIF_CTS_SLVRSTR) | NPCM_I2CFIF_CTS_RXF_TXE;
485	iowrite8(val, bus->reg + NPCM_I2CFIF_CTS);
486}
487
488static inline void npcm_i2c_clear_tx_fifo(struct npcm_i2c *bus)
489{
490	u8 val;
491
492	val = ioread8(bus->reg + NPCM_I2CTXF_STS);
493	val = val | NPCM_I2CTXF_STS_TX_THST;
494	iowrite8(val, bus->reg + NPCM_I2CTXF_STS);
495}
496
497static inline void npcm_i2c_clear_rx_fifo(struct npcm_i2c *bus)
498{
499	u8 val;
500
501	val = ioread8(bus->reg + NPCM_I2CRXF_STS);
502	val = val | NPCM_I2CRXF_STS_RX_THST;
503	iowrite8(val, bus->reg + NPCM_I2CRXF_STS);
504}
505
506static void npcm_i2c_int_enable(struct npcm_i2c *bus, bool enable)
507{
508	u8 val;
509
510	val = ioread8(bus->reg + NPCM_I2CCTL1);
511	val &= ~NPCM_I2CCTL1_RWS;
512	if (enable)
513		val |= NPCM_I2CCTL1_INTEN;
514	else
515		val &= ~NPCM_I2CCTL1_INTEN;
516	iowrite8(val, bus->reg + NPCM_I2CCTL1);
517}
518
519static inline void npcm_i2c_master_start(struct npcm_i2c *bus)
520{
521	u8 val;
522
523	val = ioread8(bus->reg + NPCM_I2CCTL1);
524	val &= ~(NPCM_I2CCTL1_STOP | NPCM_I2CCTL1_ACK);
525	val |= NPCM_I2CCTL1_START;
526	iowrite8(val, bus->reg + NPCM_I2CCTL1);
527}
528
529static inline void npcm_i2c_master_stop(struct npcm_i2c *bus)
530{
531	u8 val;
532
533	/*
534	 * override HW issue: I2C may fail to supply stop condition in Master
535	 * Write operation.
536	 * Need to delay at least 5 us from the last int, before issueing a stop
537	 */
538	udelay(10); /* function called from interrupt, can't sleep */
539	val = ioread8(bus->reg + NPCM_I2CCTL1);
540	val &= ~(NPCM_I2CCTL1_START | NPCM_I2CCTL1_ACK);
541	val |= NPCM_I2CCTL1_STOP;
542	iowrite8(val, bus->reg + NPCM_I2CCTL1);
543
544	if (!bus->fifo_use)
545		return;
546
547	npcm_i2c_select_bank(bus, I2C_BANK_1);
548
549	if (bus->operation == I2C_READ_OPER)
550		npcm_i2c_clear_rx_fifo(bus);
551	else
552		npcm_i2c_clear_tx_fifo(bus);
553	npcm_i2c_clear_fifo_int(bus);
554	iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
555}
556
557static inline void npcm_i2c_stall_after_start(struct npcm_i2c *bus, bool stall)
558{
559	u8 val;
560
561	val = ioread8(bus->reg + NPCM_I2CCTL1);
562	val &= ~NPCM_I2CCTL1_RWS;
563	if (stall)
564		val |= NPCM_I2CCTL1_STASTRE;
565	else
566		val &= ~NPCM_I2CCTL1_STASTRE;
567	iowrite8(val, bus->reg + NPCM_I2CCTL1);
568}
569
570static inline void npcm_i2c_nack(struct npcm_i2c *bus)
571{
572	u8 val;
573
574	val = ioread8(bus->reg + NPCM_I2CCTL1);
575	val &= ~(NPCM_I2CCTL1_STOP | NPCM_I2CCTL1_START);
576	val |= NPCM_I2CCTL1_ACK;
577	iowrite8(val, bus->reg + NPCM_I2CCTL1);
578}
579
580static inline void npcm_i2c_clear_master_status(struct npcm_i2c *bus)
581{
582	u8 val;
583
584	/* Clear NEGACK, STASTR and BER bits */
585	val = NPCM_I2CST_BER | NPCM_I2CST_NEGACK | NPCM_I2CST_STASTR;
586	iowrite8(val, bus->reg + NPCM_I2CST);
587}
588
589#if IS_ENABLED(CONFIG_I2C_SLAVE)
590static void npcm_i2c_slave_int_enable(struct npcm_i2c *bus, bool enable)
591{
592	u8 i2cctl1;
593
594	/* enable interrupt on slave match: */
595	i2cctl1 = ioread8(bus->reg + NPCM_I2CCTL1);
596	i2cctl1 &= ~NPCM_I2CCTL1_RWS;
597	if (enable)
598		i2cctl1 |= NPCM_I2CCTL1_NMINTE;
599	else
600		i2cctl1 &= ~NPCM_I2CCTL1_NMINTE;
601	iowrite8(i2cctl1, bus->reg + NPCM_I2CCTL1);
602}
603
604static int npcm_i2c_slave_enable(struct npcm_i2c *bus, enum i2c_addr addr_type,
605				 u8 addr, bool enable)
606{
607	u8 i2cctl1;
608	u8 i2cctl3;
609	u8 sa_reg;
610
611	sa_reg = (addr & 0x7F) | FIELD_PREP(NPCM_I2CADDR_SAEN, enable);
612	if (addr_type == I2C_GC_ADDR) {
613		i2cctl1 = ioread8(bus->reg + NPCM_I2CCTL1);
614		if (enable)
615			i2cctl1 |= NPCM_I2CCTL1_GCMEN;
616		else
617			i2cctl1 &= ~NPCM_I2CCTL1_GCMEN;
618		iowrite8(i2cctl1, bus->reg + NPCM_I2CCTL1);
619		return 0;
620	} else if (addr_type == I2C_ARP_ADDR) {
621		i2cctl3 = ioread8(bus->reg + NPCM_I2CCTL3);
622		if (enable)
623			i2cctl3 |= I2CCTL3_ARPMEN;
624		else
625			i2cctl3 &= ~I2CCTL3_ARPMEN;
626		iowrite8(i2cctl3, bus->reg + NPCM_I2CCTL3);
627		return 0;
628	}
629	if (addr_type > I2C_SLAVE_ADDR2 && addr_type <= I2C_SLAVE_ADDR10)
630		dev_err(bus->dev, "try to enable more than 2 SA not supported\n");
631
632	if (addr_type >= I2C_ARP_ADDR)
633		return -EFAULT;
634
635	/* Set and enable the address */
636	iowrite8(sa_reg, bus->reg + npcm_i2caddr[addr_type]);
637	npcm_i2c_slave_int_enable(bus, enable);
638
639	return 0;
640}
641#endif
642
643static void npcm_i2c_reset(struct npcm_i2c *bus)
644{
645	/*
646	 * Save I2CCTL1 relevant bits. It is being cleared when the module
647	 *  is disabled.
648	 */
649	u8 i2cctl1;
650#if IS_ENABLED(CONFIG_I2C_SLAVE)
651	u8 addr;
652#endif
653
654	i2cctl1 = ioread8(bus->reg + NPCM_I2CCTL1);
655
656	npcm_i2c_disable(bus);
657	npcm_i2c_enable(bus);
658
659	/* Restore NPCM_I2CCTL1 Status */
660	i2cctl1 &= ~NPCM_I2CCTL1_RWS;
661	iowrite8(i2cctl1, bus->reg + NPCM_I2CCTL1);
662
663	/* Clear BB (BUS BUSY) bit */
664	iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
665	iowrite8(0xFF, bus->reg + NPCM_I2CST);
666
667	/* Clear and disable EOB */
668	npcm_i2c_eob_int(bus, false);
669
670	/* Clear all fifo bits: */
671	iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS);
672
673#if IS_ENABLED(CONFIG_I2C_SLAVE)
674	if (bus->slave) {
675		addr = bus->slave->addr;
676		npcm_i2c_slave_enable(bus, I2C_SLAVE_ADDR1, addr, true);
677	}
678#endif
679
680	/* Clear status bits for spurious interrupts */
681	npcm_i2c_clear_master_status(bus);
682
683	bus->state = I2C_IDLE;
684}
685
686static inline bool npcm_i2c_is_master(struct npcm_i2c *bus)
687{
688	return !!FIELD_GET(NPCM_I2CST_MASTER, ioread8(bus->reg + NPCM_I2CST));
689}
690
691static void npcm_i2c_callback(struct npcm_i2c *bus,
692			      enum i2c_state_ind op_status, u16 info)
693{
694	struct i2c_msg *msgs;
695	int msgs_num;
696	bool do_complete = false;
697
698	msgs = bus->msgs;
699	msgs_num = bus->msgs_num;
700	/*
701	 * check that transaction was not timed-out, and msgs still
702	 * holds a valid value.
703	 */
704	if (!msgs)
705		return;
706
707	if (completion_done(&bus->cmd_complete))
708		return;
709
710	switch (op_status) {
711	case I2C_MASTER_DONE_IND:
712		bus->cmd_err = bus->msgs_num;
713		if (bus->tx_complete_cnt < ULLONG_MAX)
714			bus->tx_complete_cnt++;
715		fallthrough;
716	case I2C_BLOCK_BYTES_ERR_IND:
717		/* Master tx finished and all transmit bytes were sent */
718		if (bus->msgs) {
719			if (msgs[0].flags & I2C_M_RD)
720				msgs[0].len = info;
721			else if (msgs_num == 2 &&
722				 msgs[1].flags & I2C_M_RD)
723				msgs[1].len = info;
724		}
725		do_complete = true;
726		break;
727	case I2C_NACK_IND:
728		/* MASTER transmit got a NACK before tx all bytes */
729		bus->cmd_err = -ENXIO;
730		do_complete = true;
731		break;
732	case I2C_BUS_ERR_IND:
733		/* Bus error */
734		bus->cmd_err = -EAGAIN;
735		do_complete = true;
736		break;
737	case I2C_WAKE_UP_IND:
738		/* I2C wake up */
739		break;
740	default:
741		break;
742	}
743
744	bus->operation = I2C_NO_OPER;
745#if IS_ENABLED(CONFIG_I2C_SLAVE)
746	if (bus->slave)
747		bus->master_or_slave = I2C_SLAVE;
748#endif
749	if (do_complete)
750		complete(&bus->cmd_complete);
751}
752
753static u8 npcm_i2c_fifo_usage(struct npcm_i2c *bus)
754{
755	if (bus->operation == I2C_WRITE_OPER)
756		return (bus->data->txf_sts_tx_bytes &
757			ioread8(bus->reg + NPCM_I2CTXF_STS));
758	if (bus->operation == I2C_READ_OPER)
759		return (bus->data->rxf_sts_rx_bytes &
760			ioread8(bus->reg + NPCM_I2CRXF_STS));
761	return 0;
762}
763
764static void npcm_i2c_write_to_fifo_master(struct npcm_i2c *bus, u16 max_bytes)
765{
766	u8 size_free_fifo;
767
768	/*
769	 * Fill the FIFO, while the FIFO is not full and there are more bytes
770	 * to write
771	 */
772	size_free_fifo = bus->data->fifo_size - npcm_i2c_fifo_usage(bus);
773	while (max_bytes-- && size_free_fifo) {
774		if (bus->wr_ind < bus->wr_size)
775			npcm_i2c_wr_byte(bus, bus->wr_buf[bus->wr_ind++]);
776		else
777			npcm_i2c_wr_byte(bus, 0xFF);
778		size_free_fifo = bus->data->fifo_size - npcm_i2c_fifo_usage(bus);
779	}
780}
781
782/*
783 * npcm_i2c_set_fifo:
784 * configure the FIFO before using it. If nread is -1 RX FIFO will not be
785 * configured. same for nwrite
786 */
787static void npcm_i2c_set_fifo(struct npcm_i2c *bus, int nread, int nwrite)
788{
789	u8 rxf_ctl = 0;
790
791	if (!bus->fifo_use)
792		return;
793	npcm_i2c_select_bank(bus, I2C_BANK_1);
794	npcm_i2c_clear_tx_fifo(bus);
795	npcm_i2c_clear_rx_fifo(bus);
796
797	/* configure RX FIFO */
798	if (nread > 0) {
799		rxf_ctl = min_t(int, nread, bus->data->fifo_size);
800
801		/* set LAST bit. if LAST is set next FIFO packet is nacked */
802		if (nread <= bus->data->fifo_size)
803			rxf_ctl |= bus->data->rxf_ctl_last_pec;
804
805		/*
806		 * if we are about to read the first byte in blk rd mode,
807		 * don't NACK it. If slave returns zero size HW can't NACK
808		 * it immediately, it will read extra byte and then NACK.
809		 */
810		if (bus->rd_ind == 0 && bus->read_block_use) {
811			/* set fifo to read one byte, no last: */
812			rxf_ctl = 1;
813		}
814
815		/* set fifo size: */
816		iowrite8(rxf_ctl, bus->reg + NPCM_I2CRXF_CTL);
817	}
818
819	/* configure TX FIFO */
820	if (nwrite > 0) {
821		if (nwrite > bus->data->fifo_size)
822			/* data to send is more then FIFO size. */
823			iowrite8(bus->data->fifo_size, bus->reg + NPCM_I2CTXF_CTL);
824		else
825			iowrite8(nwrite, bus->reg + NPCM_I2CTXF_CTL);
826
827		npcm_i2c_clear_tx_fifo(bus);
828	}
829}
830
831static void npcm_i2c_read_fifo(struct npcm_i2c *bus, u8 bytes_in_fifo)
832{
833	u8 data;
834
835	while (bytes_in_fifo--) {
836		data = npcm_i2c_rd_byte(bus);
837		if (bus->rd_ind < bus->rd_size)
838			bus->rd_buf[bus->rd_ind++] = data;
839	}
840}
841
842static void npcm_i2c_master_abort(struct npcm_i2c *bus)
843{
844	/* Only current master is allowed to issue a stop condition */
845	if (!npcm_i2c_is_master(bus))
846		return;
847
848	npcm_i2c_eob_int(bus, true);
849	npcm_i2c_master_stop(bus);
850	npcm_i2c_clear_master_status(bus);
851}
852
853#if IS_ENABLED(CONFIG_I2C_SLAVE)
854static u8 npcm_i2c_get_slave_addr(struct npcm_i2c *bus, enum i2c_addr addr_type)
855{
856	u8 slave_add;
857
858	if (addr_type > I2C_SLAVE_ADDR2 && addr_type <= I2C_SLAVE_ADDR10)
859		dev_err(bus->dev, "get slave: try to use more than 2 SA not supported\n");
860
861	slave_add = ioread8(bus->reg + npcm_i2caddr[(int)addr_type]);
862
863	return slave_add;
864}
865
866static int npcm_i2c_remove_slave_addr(struct npcm_i2c *bus, u8 slave_add)
867{
868	int i;
869
870	/* Set the enable bit */
871	slave_add |= 0x80;
872
873	for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OWN_ADDR_SUPPORTED; i++) {
874		if (ioread8(bus->reg + npcm_i2caddr[i]) == slave_add)
875			iowrite8(0, bus->reg + npcm_i2caddr[i]);
876	}
877
878	return 0;
879}
880
881static void npcm_i2c_write_fifo_slave(struct npcm_i2c *bus, u16 max_bytes)
882{
883	/*
884	 * Fill the FIFO, while the FIFO is not full and there are more bytes
885	 * to write
886	 */
887	npcm_i2c_clear_fifo_int(bus);
888	npcm_i2c_clear_tx_fifo(bus);
889	iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
890	while (max_bytes-- && bus->data->fifo_size != npcm_i2c_fifo_usage(bus)) {
891		if (bus->slv_wr_size <= 0)
892			break;
893		bus->slv_wr_ind = bus->slv_wr_ind & (bus->data->fifo_size - 1);
894		npcm_i2c_wr_byte(bus, bus->slv_wr_buf[bus->slv_wr_ind]);
895		bus->slv_wr_ind++;
896		bus->slv_wr_ind = bus->slv_wr_ind & (bus->data->fifo_size - 1);
897		bus->slv_wr_size--;
898	}
899}
900
901static void npcm_i2c_read_fifo_slave(struct npcm_i2c *bus, u8 bytes_in_fifo)
902{
903	u8 data;
904
905	if (!bus->slave)
906		return;
907
908	while (bytes_in_fifo--) {
909		data = npcm_i2c_rd_byte(bus);
910
911		bus->slv_rd_ind = bus->slv_rd_ind & (bus->data->fifo_size - 1);
912		bus->slv_rd_buf[bus->slv_rd_ind] = data;
913		bus->slv_rd_ind++;
914
915		/* 1st byte is length in block protocol: */
916		if (bus->slv_rd_ind == 1 && bus->read_block_use)
917			bus->slv_rd_size = data + bus->PEC_use + 1;
918	}
919}
920
921static int npcm_i2c_slave_get_wr_buf(struct npcm_i2c *bus)
922{
923	int i;
924	u8 value;
925	int ind;
926	int ret = bus->slv_wr_ind;
927
928	/* fill a cyclic buffer */
929	for (i = 0; i < bus->data->fifo_size; i++) {
930		if (bus->slv_wr_size >= bus->data->fifo_size)
931			break;
932		if (bus->state == I2C_SLAVE_MATCH) {
933			i2c_slave_event(bus->slave, I2C_SLAVE_READ_REQUESTED, &value);
934			bus->state = I2C_OPER_STARTED;
935		} else {
936			i2c_slave_event(bus->slave, I2C_SLAVE_READ_PROCESSED, &value);
937		}
938		ind = (bus->slv_wr_ind + bus->slv_wr_size) & (bus->data->fifo_size - 1);
939		bus->slv_wr_buf[ind] = value;
940		bus->slv_wr_size++;
941	}
942	return bus->data->fifo_size - ret;
943}
944
945static void npcm_i2c_slave_send_rd_buf(struct npcm_i2c *bus)
946{
947	int i;
948
949	for (i = 0; i < bus->slv_rd_ind; i++)
950		i2c_slave_event(bus->slave, I2C_SLAVE_WRITE_RECEIVED,
951				&bus->slv_rd_buf[i]);
952	/*
953	 * once we send bytes up, need to reset the counter of the wr buf
954	 * got data from master (new offset in device), ignore wr fifo:
955	 */
956	if (bus->slv_rd_ind) {
957		bus->slv_wr_size = 0;
958		bus->slv_wr_ind = 0;
959	}
960
961	bus->slv_rd_ind = 0;
962	bus->slv_rd_size = bus->adap.quirks->max_read_len;
963
964	npcm_i2c_clear_fifo_int(bus);
965	npcm_i2c_clear_rx_fifo(bus);
966}
967
968static void npcm_i2c_slave_receive(struct npcm_i2c *bus, u16 nread,
969				   u8 *read_data)
970{
971	bus->state = I2C_OPER_STARTED;
972	bus->operation = I2C_READ_OPER;
973	bus->slv_rd_size = nread;
974	bus->slv_rd_ind = 0;
975
976	iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
977	iowrite8(bus->data->fifo_size, bus->reg + NPCM_I2CRXF_CTL);
978	npcm_i2c_clear_tx_fifo(bus);
979	npcm_i2c_clear_rx_fifo(bus);
980}
981
982static void npcm_i2c_slave_xmit(struct npcm_i2c *bus, u16 nwrite,
983				u8 *write_data)
984{
985	if (nwrite == 0)
986		return;
987
988	bus->operation = I2C_WRITE_OPER;
989
990	/* get the next buffer */
991	npcm_i2c_slave_get_wr_buf(bus);
992	npcm_i2c_write_fifo_slave(bus, nwrite);
993}
994
995/*
996 * npcm_i2c_slave_wr_buf_sync:
997 * currently slave IF only supports single byte operations.
998 * in order to utilize the npcm HW FIFO, the driver will ask for 16 bytes
999 * at a time, pack them in buffer, and then transmit them all together
1000 * to the FIFO and onward to the bus.
1001 * NACK on read will be once reached to bus->adap->quirks->max_read_len.
1002 * sending a NACK wherever the backend requests for it is not supported.
1003 * the next two functions allow reading to local buffer before writing it all
1004 * to the HW FIFO.
1005 */
1006static void npcm_i2c_slave_wr_buf_sync(struct npcm_i2c *bus)
1007{
1008	int left_in_fifo;
1009
1010	left_in_fifo = bus->data->txf_sts_tx_bytes &
1011			ioread8(bus->reg + NPCM_I2CTXF_STS);
1012
1013	/* fifo already full: */
1014	if (left_in_fifo >= bus->data->fifo_size ||
1015	    bus->slv_wr_size >= bus->data->fifo_size)
1016		return;
1017
1018	/* update the wr fifo index back to the untransmitted bytes: */
1019	bus->slv_wr_ind = bus->slv_wr_ind - left_in_fifo;
1020	bus->slv_wr_size = bus->slv_wr_size + left_in_fifo;
1021
1022	if (bus->slv_wr_ind < 0)
1023		bus->slv_wr_ind += bus->data->fifo_size;
1024}
1025
1026static void npcm_i2c_slave_rd_wr(struct npcm_i2c *bus)
1027{
1028	if (NPCM_I2CST_XMIT & ioread8(bus->reg + NPCM_I2CST)) {
1029		/*
1030		 * Slave got an address match with direction bit 1 so it should
1031		 * transmit data. Write till the master will NACK
1032		 */
1033		bus->operation = I2C_WRITE_OPER;
1034		npcm_i2c_slave_xmit(bus, bus->adap.quirks->max_write_len,
1035				    bus->slv_wr_buf);
1036	} else {
1037		/*
1038		 * Slave got an address match with direction bit 0 so it should
1039		 * receive data.
1040		 * this module does not support saying no to bytes.
1041		 * it will always ACK.
1042		 */
1043		bus->operation = I2C_READ_OPER;
1044		npcm_i2c_read_fifo_slave(bus, npcm_i2c_fifo_usage(bus));
1045		bus->stop_ind = I2C_SLAVE_RCV_IND;
1046		npcm_i2c_slave_send_rd_buf(bus);
1047		npcm_i2c_slave_receive(bus, bus->adap.quirks->max_read_len,
1048				       bus->slv_rd_buf);
1049	}
1050}
1051
1052static irqreturn_t npcm_i2c_int_slave_handler(struct npcm_i2c *bus)
1053{
1054	u8 val;
1055	irqreturn_t ret = IRQ_NONE;
1056	u8 i2cst = ioread8(bus->reg + NPCM_I2CST);
1057
1058	/* Slave: A NACK has occurred */
1059	if (NPCM_I2CST_NEGACK & i2cst) {
1060		bus->stop_ind = I2C_NACK_IND;
1061		npcm_i2c_slave_wr_buf_sync(bus);
1062		if (bus->fifo_use)
1063			/* clear the FIFO */
1064			iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO,
1065				 bus->reg + NPCM_I2CFIF_CTS);
1066
1067		/* In slave write, NACK is OK, otherwise it is a problem */
1068		bus->stop_ind = I2C_NO_STATUS_IND;
1069		bus->operation = I2C_NO_OPER;
1070		bus->own_slave_addr = 0xFF;
1071
1072		/*
1073		 * Slave has to wait for STOP to decide this is the end
1074		 * of the transaction. tx is not yet considered as done
1075		 */
1076		iowrite8(NPCM_I2CST_NEGACK, bus->reg + NPCM_I2CST);
1077
1078		ret = IRQ_HANDLED;
1079	}
1080
1081	/* Slave mode: a Bus Error (BER) has been identified */
1082	if (NPCM_I2CST_BER & i2cst) {
1083		/*
1084		 * Check whether bus arbitration or Start or Stop during data
1085		 * xfer bus arbitration problem should not result in recovery
1086		 */
1087		bus->stop_ind = I2C_BUS_ERR_IND;
1088
1089		/* wait for bus busy before clear fifo */
1090		iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS);
1091
1092		bus->state = I2C_IDLE;
1093
1094		/*
1095		 * in BER case we might get 2 interrupts: one for slave one for
1096		 * master ( for a channel which is master\slave switching)
1097		 */
1098		if (completion_done(&bus->cmd_complete) == false) {
1099			bus->cmd_err = -EIO;
1100			complete(&bus->cmd_complete);
1101		}
1102		bus->own_slave_addr = 0xFF;
1103		iowrite8(NPCM_I2CST_BER, bus->reg + NPCM_I2CST);
1104		ret = IRQ_HANDLED;
1105	}
1106
1107	/* A Slave Stop Condition has been identified */
1108	if (NPCM_I2CST_SLVSTP & i2cst) {
1109		u8 bytes_in_fifo = npcm_i2c_fifo_usage(bus);
1110
1111		bus->stop_ind = I2C_SLAVE_DONE_IND;
1112
1113		if (bus->operation == I2C_READ_OPER)
1114			npcm_i2c_read_fifo_slave(bus, bytes_in_fifo);
1115
1116		/* if the buffer is empty nothing will be sent */
1117		npcm_i2c_slave_send_rd_buf(bus);
1118
1119		/* Slave done transmitting or receiving */
1120		bus->stop_ind = I2C_NO_STATUS_IND;
1121
1122		/*
1123		 * Note, just because we got here, it doesn't mean we through
1124		 * away the wr buffer.
1125		 * we keep it until the next received offset.
1126		 */
1127		bus->operation = I2C_NO_OPER;
1128		bus->own_slave_addr = 0xFF;
1129		i2c_slave_event(bus->slave, I2C_SLAVE_STOP, 0);
1130		iowrite8(NPCM_I2CST_SLVSTP, bus->reg + NPCM_I2CST);
1131		if (bus->fifo_use) {
1132			npcm_i2c_clear_fifo_int(bus);
1133			npcm_i2c_clear_rx_fifo(bus);
1134			npcm_i2c_clear_tx_fifo(bus);
1135
1136			iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO,
1137				 bus->reg + NPCM_I2CFIF_CTS);
1138		}
1139		bus->state = I2C_IDLE;
1140		ret = IRQ_HANDLED;
1141	}
1142
1143	/* restart condition occurred and Rx-FIFO was not empty */
1144	if (bus->fifo_use && FIELD_GET(NPCM_I2CFIF_CTS_SLVRSTR,
1145				       ioread8(bus->reg + NPCM_I2CFIF_CTS))) {
1146		bus->stop_ind = I2C_SLAVE_RESTART_IND;
1147		bus->master_or_slave = I2C_SLAVE;
1148		if (bus->operation == I2C_READ_OPER)
1149			npcm_i2c_read_fifo_slave(bus, npcm_i2c_fifo_usage(bus));
1150		bus->operation = I2C_WRITE_OPER;
1151		iowrite8(0, bus->reg + NPCM_I2CRXF_CTL);
1152		val = NPCM_I2CFIF_CTS_CLR_FIFO | NPCM_I2CFIF_CTS_SLVRSTR |
1153		      NPCM_I2CFIF_CTS_RXF_TXE;
1154		iowrite8(val, bus->reg + NPCM_I2CFIF_CTS);
1155		npcm_i2c_slave_rd_wr(bus);
1156		ret = IRQ_HANDLED;
1157	}
1158
1159	/* A Slave Address Match has been identified */
1160	if (NPCM_I2CST_NMATCH & i2cst) {
1161		u8 info = 0;
1162
1163		/* Address match automatically implies slave mode */
1164		bus->master_or_slave = I2C_SLAVE;
1165		npcm_i2c_clear_fifo_int(bus);
1166		npcm_i2c_clear_rx_fifo(bus);
1167		npcm_i2c_clear_tx_fifo(bus);
1168		iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
1169		iowrite8(bus->data->fifo_size, bus->reg + NPCM_I2CRXF_CTL);
1170		if (NPCM_I2CST_XMIT & i2cst) {
1171			bus->operation = I2C_WRITE_OPER;
1172		} else {
1173			i2c_slave_event(bus->slave, I2C_SLAVE_WRITE_REQUESTED,
1174					&info);
1175			bus->operation = I2C_READ_OPER;
1176		}
1177		if (bus->own_slave_addr == 0xFF) {
1178			/* Check which type of address match */
1179			val = ioread8(bus->reg + NPCM_I2CCST);
1180			if (NPCM_I2CCST_MATCH & val) {
1181				u16 addr;
1182				enum i2c_addr eaddr;
1183				u8 i2ccst2;
1184				u8 i2ccst3;
1185
1186				i2ccst3 = ioread8(bus->reg + NPCM_I2CCST3);
1187				i2ccst2 = ioread8(bus->reg + NPCM_I2CCST2);
1188
1189				/*
1190				 * the i2c module can response to 10 own SA.
1191				 * check which one was addressed by the master.
1192				 * respond to the first one.
1193				 */
1194				addr = ((i2ccst3 & 0x07) << 7) |
1195					(i2ccst2 & 0x7F);
1196				info = ffs(addr);
1197				eaddr = (enum i2c_addr)info;
1198				addr = npcm_i2c_get_slave_addr(bus, eaddr);
1199				addr &= 0x7F;
1200				bus->own_slave_addr = addr;
1201				if (bus->PEC_mask & BIT(info))
1202					bus->PEC_use = true;
1203				else
1204					bus->PEC_use = false;
1205			} else {
1206				if (NPCM_I2CCST_GCMATCH & val)
1207					bus->own_slave_addr = 0;
1208				if (NPCM_I2CCST_ARPMATCH & val)
1209					bus->own_slave_addr = 0x61;
1210			}
1211		} else {
1212			/*
1213			 *  Slave match can happen in two options:
1214			 *  1. Start, SA, read (slave read without further ado)
1215			 *  2. Start, SA, read, data, restart, SA, read,  ...
1216			 *     (slave read in fragmented mode)
1217			 *  3. Start, SA, write, data, restart, SA, read, ..
1218			 *     (regular write-read mode)
1219			 */
1220			if ((bus->state == I2C_OPER_STARTED &&
1221			     bus->operation == I2C_READ_OPER &&
1222			     bus->stop_ind == I2C_SLAVE_XMIT_IND) ||
1223			     bus->stop_ind == I2C_SLAVE_RCV_IND) {
1224				/* slave tx after slave rx w/o STOP */
1225				bus->stop_ind = I2C_SLAVE_RESTART_IND;
1226			}
1227		}
1228
1229		if (NPCM_I2CST_XMIT & i2cst)
1230			bus->stop_ind = I2C_SLAVE_XMIT_IND;
1231		else
1232			bus->stop_ind = I2C_SLAVE_RCV_IND;
1233		bus->state = I2C_SLAVE_MATCH;
1234		npcm_i2c_slave_rd_wr(bus);
1235		iowrite8(NPCM_I2CST_NMATCH, bus->reg + NPCM_I2CST);
1236		ret = IRQ_HANDLED;
1237	}
1238
1239	/* Slave SDA status is set - tx or rx */
1240	if ((NPCM_I2CST_SDAST & i2cst) ||
1241	    (bus->fifo_use &&
1242	    (npcm_i2c_tx_fifo_empty(bus) || npcm_i2c_rx_fifo_full(bus)))) {
1243		npcm_i2c_slave_rd_wr(bus);
1244		iowrite8(NPCM_I2CST_SDAST, bus->reg + NPCM_I2CST);
1245		ret = IRQ_HANDLED;
1246	} /* SDAST */
1247
1248	/*
1249	 * If irq is not one of the above, make sure EOB is disabled and all
1250	 * status bits are cleared.
1251	 */
1252	if (ret == IRQ_NONE) {
1253		npcm_i2c_eob_int(bus, false);
1254		npcm_i2c_clear_master_status(bus);
1255	}
1256
1257	return IRQ_HANDLED;
1258}
1259
1260static int npcm_i2c_reg_slave(struct i2c_client *client)
1261{
1262	unsigned long lock_flags;
1263	struct npcm_i2c *bus = i2c_get_adapdata(client->adapter);
1264
1265	bus->slave = client;
1266
1267	if (client->flags & I2C_CLIENT_TEN)
1268		return -EAFNOSUPPORT;
1269
1270	spin_lock_irqsave(&bus->lock, lock_flags);
1271
1272	npcm_i2c_init_params(bus);
1273	bus->slv_rd_size = 0;
1274	bus->slv_wr_size = 0;
1275	bus->slv_rd_ind = 0;
1276	bus->slv_wr_ind = 0;
1277	if (client->flags & I2C_CLIENT_PEC)
1278		bus->PEC_use = true;
1279
1280	dev_info(bus->dev, "i2c%d register slave SA=0x%x, PEC=%d\n", bus->num,
1281		 client->addr, bus->PEC_use);
1282
1283	npcm_i2c_slave_enable(bus, I2C_SLAVE_ADDR1, client->addr, true);
1284	npcm_i2c_clear_fifo_int(bus);
1285	npcm_i2c_clear_rx_fifo(bus);
1286	npcm_i2c_clear_tx_fifo(bus);
1287	npcm_i2c_slave_int_enable(bus, true);
1288
1289	spin_unlock_irqrestore(&bus->lock, lock_flags);
1290	return 0;
1291}
1292
1293static int npcm_i2c_unreg_slave(struct i2c_client *client)
1294{
1295	struct npcm_i2c *bus = client->adapter->algo_data;
1296	unsigned long lock_flags;
1297
1298	spin_lock_irqsave(&bus->lock, lock_flags);
1299	if (!bus->slave) {
1300		spin_unlock_irqrestore(&bus->lock, lock_flags);
1301		return -EINVAL;
1302	}
1303	npcm_i2c_slave_int_enable(bus, false);
1304	npcm_i2c_remove_slave_addr(bus, client->addr);
1305	bus->slave = NULL;
1306	spin_unlock_irqrestore(&bus->lock, lock_flags);
1307	return 0;
1308}
1309#endif /* CONFIG_I2C_SLAVE */
1310
1311static void npcm_i2c_master_fifo_read(struct npcm_i2c *bus)
1312{
1313	int rcount;
1314	int fifo_bytes;
1315	enum i2c_state_ind ind = I2C_MASTER_DONE_IND;
1316
1317	fifo_bytes = npcm_i2c_fifo_usage(bus);
1318	rcount = bus->rd_size - bus->rd_ind;
1319
1320	/*
1321	 * In order not to change the RX_TRH during transaction (we found that
1322	 * this might be problematic if it takes too much time to read the FIFO)
1323	 * we read the data in the following way. If the number of bytes to
1324	 * read == FIFO Size + C (where C < FIFO Size)then first read C bytes
1325	 * and in the next int we read rest of the data.
1326	 */
1327	if (rcount < (2 * bus->data->fifo_size) && rcount > bus->data->fifo_size)
1328		fifo_bytes = rcount - bus->data->fifo_size;
1329
1330	if (rcount <= fifo_bytes) {
1331		/* last bytes are about to be read - end of tx */
1332		bus->state = I2C_STOP_PENDING;
1333		bus->stop_ind = ind;
1334		npcm_i2c_eob_int(bus, true);
1335		/* Stop should be set before reading last byte. */
1336		npcm_i2c_master_stop(bus);
1337		npcm_i2c_read_fifo(bus, fifo_bytes);
1338	} else {
1339		npcm_i2c_read_fifo(bus, fifo_bytes);
1340		rcount = bus->rd_size - bus->rd_ind;
1341		npcm_i2c_set_fifo(bus, rcount, -1);
1342	}
1343}
1344
1345static void npcm_i2c_irq_master_handler_write(struct npcm_i2c *bus)
1346{
1347	u16 wcount;
1348
1349	if (bus->fifo_use)
1350		npcm_i2c_clear_tx_fifo(bus); /* clear the TX fifo status bit */
1351
1352	/* Master write operation - last byte handling */
1353	if (bus->wr_ind == bus->wr_size) {
1354		if (bus->fifo_use && npcm_i2c_fifo_usage(bus) > 0)
1355			/*
1356			 * No more bytes to send (to add to the FIFO),
1357			 * however the FIFO is not empty yet. It is
1358			 * still in the middle of tx. Currently there's nothing
1359			 * to do except for waiting to the end of the tx
1360			 * We will get an int when the FIFO will get empty.
1361			 */
1362			return;
1363
1364		if (bus->rd_size == 0) {
1365			/* all bytes have been written, in wr only operation */
1366			npcm_i2c_eob_int(bus, true);
1367			bus->state = I2C_STOP_PENDING;
1368			bus->stop_ind = I2C_MASTER_DONE_IND;
1369			npcm_i2c_master_stop(bus);
1370			/* Clear SDA Status bit (by writing dummy byte) */
1371			npcm_i2c_wr_byte(bus, 0xFF);
1372
1373		} else {
1374			/* last write-byte written on previous int - restart */
1375			npcm_i2c_set_fifo(bus, bus->rd_size, -1);
1376			/* Generate repeated start upon next write to SDA */
1377			npcm_i2c_master_start(bus);
1378
1379			/*
1380			 * Receiving one byte only - stall after successful
1381			 * completion of send address byte. If we NACK here, and
1382			 * slave doesn't ACK the address, we might
1383			 * unintentionally NACK the next multi-byte read.
1384			 */
1385			if (bus->rd_size == 1)
1386				npcm_i2c_stall_after_start(bus, true);
1387
1388			/* Next int will occur on read */
1389			bus->operation = I2C_READ_OPER;
1390			/* send the slave address in read direction */
1391			npcm_i2c_wr_byte(bus, bus->dest_addr | 0x1);
1392		}
1393	} else {
1394		/* write next byte not last byte and not slave address */
1395		if (!bus->fifo_use || bus->wr_size == 1) {
1396			npcm_i2c_wr_byte(bus, bus->wr_buf[bus->wr_ind++]);
1397		} else {
1398			wcount = bus->wr_size - bus->wr_ind;
1399			npcm_i2c_set_fifo(bus, -1, wcount);
1400			if (wcount)
1401				npcm_i2c_write_to_fifo_master(bus, wcount);
1402		}
1403	}
1404}
1405
1406static void npcm_i2c_irq_master_handler_read(struct npcm_i2c *bus)
1407{
1408	u16 block_extra_bytes_size;
1409	u8 data;
1410
1411	/* added bytes to the packet: */
1412	block_extra_bytes_size = bus->read_block_use + bus->PEC_use;
1413
1414	/*
1415	 * Perform master read, distinguishing between last byte and the rest of
1416	 * the bytes. The last byte should be read when the clock is stopped
1417	 */
1418	if (bus->rd_ind == 0) { /* first byte handling: */
1419		if (bus->read_block_use) {
1420			/* first byte in block protocol is the size: */
1421			data = npcm_i2c_rd_byte(bus);
1422			data = clamp_val(data, 1, I2C_SMBUS_BLOCK_MAX);
1423			bus->rd_size = data + block_extra_bytes_size;
1424			bus->rd_buf[bus->rd_ind++] = data;
1425
1426			/* clear RX FIFO interrupt status: */
1427			if (bus->fifo_use) {
1428				data = ioread8(bus->reg + NPCM_I2CFIF_CTS);
1429				data = data | NPCM_I2CFIF_CTS_RXF_TXE;
1430				iowrite8(data, bus->reg + NPCM_I2CFIF_CTS);
1431			}
1432
1433			npcm_i2c_set_fifo(bus, bus->rd_size - 1, -1);
1434			npcm_i2c_stall_after_start(bus, false);
1435		} else {
1436			npcm_i2c_clear_tx_fifo(bus);
1437			npcm_i2c_master_fifo_read(bus);
1438		}
1439	} else {
1440		if (bus->rd_size == block_extra_bytes_size &&
1441		    bus->read_block_use) {
1442			bus->state = I2C_STOP_PENDING;
1443			bus->stop_ind = I2C_BLOCK_BYTES_ERR_IND;
1444			bus->cmd_err = -EIO;
1445			npcm_i2c_eob_int(bus, true);
1446			npcm_i2c_master_stop(bus);
1447			npcm_i2c_read_fifo(bus, npcm_i2c_fifo_usage(bus));
1448		} else {
1449			npcm_i2c_master_fifo_read(bus);
1450		}
1451	}
1452}
1453
1454static void npcm_i2c_irq_handle_nmatch(struct npcm_i2c *bus)
1455{
1456	iowrite8(NPCM_I2CST_NMATCH, bus->reg + NPCM_I2CST);
1457	npcm_i2c_nack(bus);
1458	bus->stop_ind = I2C_BUS_ERR_IND;
1459	npcm_i2c_callback(bus, bus->stop_ind, npcm_i2c_get_index(bus));
1460}
1461
1462/* A NACK has occurred */
1463static void npcm_i2c_irq_handle_nack(struct npcm_i2c *bus)
1464{
1465	u8 val;
1466
1467	if (bus->nack_cnt < ULLONG_MAX)
1468		bus->nack_cnt++;
1469
1470	if (bus->fifo_use) {
1471		/*
1472		 * if there are still untransmitted bytes in TX FIFO
1473		 * reduce them from wr_ind
1474		 */
1475		if (bus->operation == I2C_WRITE_OPER)
1476			bus->wr_ind -= npcm_i2c_fifo_usage(bus);
1477
1478		/* clear the FIFO */
1479		iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS);
1480	}
1481
1482	/* In master write operation, got unexpected NACK */
1483	bus->stop_ind = I2C_NACK_IND;
1484	/* Only current master is allowed to issue Stop Condition */
1485	if (npcm_i2c_is_master(bus)) {
1486		/* stopping in the middle */
1487		npcm_i2c_eob_int(bus, false);
1488		npcm_i2c_master_stop(bus);
1489
1490		/* Clear SDA Status bit (by reading dummy byte) */
1491		npcm_i2c_rd_byte(bus);
1492
1493		/*
1494		 * The bus is released from stall only after the SW clears
1495		 * NEGACK bit. Then a Stop condition is sent.
1496		 */
1497		npcm_i2c_clear_master_status(bus);
1498		readx_poll_timeout_atomic(ioread8, bus->reg + NPCM_I2CCST, val,
1499					  !(val & NPCM_I2CCST_BUSY), 10, 200);
1500		/* Verify no status bits are still set after bus is released */
1501		npcm_i2c_clear_master_status(bus);
1502	}
1503	bus->state = I2C_IDLE;
1504
1505	/*
1506	 * In Master mode, NACK should be cleared only after STOP.
1507	 * In such case, the bus is released from stall only after the
1508	 * software clears NACK bit. Then a Stop condition is sent.
1509	 */
1510	npcm_i2c_callback(bus, bus->stop_ind, bus->wr_ind);
1511}
1512
1513	/* Master mode: a Bus Error has been identified */
1514static void npcm_i2c_irq_handle_ber(struct npcm_i2c *bus)
1515{
1516	if (bus->ber_cnt < ULLONG_MAX)
1517		bus->ber_cnt++;
1518	bus->stop_ind = I2C_BUS_ERR_IND;
1519	if (npcm_i2c_is_master(bus)) {
1520		npcm_i2c_master_abort(bus);
1521	} else {
1522		npcm_i2c_clear_master_status(bus);
1523
1524		/* Clear BB (BUS BUSY) bit */
1525		iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
1526
1527		bus->cmd_err = -EAGAIN;
1528		npcm_i2c_callback(bus, bus->stop_ind, npcm_i2c_get_index(bus));
1529	}
1530	bus->state = I2C_IDLE;
1531}
1532
1533	/* EOB: a master End Of Busy (meaning STOP completed) */
1534static void npcm_i2c_irq_handle_eob(struct npcm_i2c *bus)
1535{
1536	npcm_i2c_eob_int(bus, false);
1537	bus->state = I2C_IDLE;
1538	npcm_i2c_callback(bus, bus->stop_ind, bus->rd_ind);
1539}
1540
1541/* Address sent and requested stall occurred (Master mode) */
1542static void npcm_i2c_irq_handle_stall_after_start(struct npcm_i2c *bus)
1543{
1544	if (npcm_i2c_is_quick(bus)) {
1545		bus->state = I2C_STOP_PENDING;
1546		bus->stop_ind = I2C_MASTER_DONE_IND;
1547		npcm_i2c_eob_int(bus, true);
1548		npcm_i2c_master_stop(bus);
1549	} else if ((bus->rd_size == 1) && !bus->read_block_use) {
1550		/*
1551		 * Receiving one byte only - set NACK after ensuring
1552		 * slave ACKed the address byte.
1553		 */
1554		npcm_i2c_nack(bus);
1555	}
1556
1557	/* Reset stall-after-address-byte */
1558	npcm_i2c_stall_after_start(bus, false);
1559
1560	/* Clear stall only after setting STOP */
1561	iowrite8(NPCM_I2CST_STASTR, bus->reg + NPCM_I2CST);
1562}
1563
1564/* SDA status is set - TX or RX, master */
1565static void npcm_i2c_irq_handle_sda(struct npcm_i2c *bus, u8 i2cst)
1566{
1567	u8 fif_cts;
1568
1569	if (!npcm_i2c_is_master(bus))
1570		return;
1571
1572	if (bus->state == I2C_IDLE) {
1573		bus->stop_ind = I2C_WAKE_UP_IND;
1574
1575		if (npcm_i2c_is_quick(bus) || bus->read_block_use)
1576			/*
1577			 * Need to stall after successful
1578			 * completion of sending address byte
1579			 */
1580			npcm_i2c_stall_after_start(bus, true);
1581		else
1582			npcm_i2c_stall_after_start(bus, false);
1583
1584		/*
1585		 * Receiving one byte only - stall after successful completion
1586		 * of sending address byte If we NACK here, and slave doesn't
1587		 * ACK the address, we might unintentionally NACK the next
1588		 * multi-byte read
1589		 */
1590		if (bus->wr_size == 0 && bus->rd_size == 1)
1591			npcm_i2c_stall_after_start(bus, true);
1592
1593		/* Initiate I2C master tx */
1594
1595		/* select bank 1 for FIFO regs */
1596		npcm_i2c_select_bank(bus, I2C_BANK_1);
1597
1598		fif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS);
1599		fif_cts = fif_cts & ~NPCM_I2CFIF_CTS_SLVRSTR;
1600
1601		/* clear FIFO and relevant status bits. */
1602		fif_cts = fif_cts | NPCM_I2CFIF_CTS_CLR_FIFO;
1603		iowrite8(fif_cts, bus->reg + NPCM_I2CFIF_CTS);
1604
1605		/* re-enable */
1606		fif_cts = fif_cts | NPCM_I2CFIF_CTS_RXF_TXE;
1607		iowrite8(fif_cts, bus->reg + NPCM_I2CFIF_CTS);
1608
1609		/*
1610		 * Configure the FIFO threshold:
1611		 * according to the needed # of bytes to read.
1612		 * Note: due to HW limitation can't config the rx fifo before it
1613		 * got and ACK on the restart. LAST bit will not be reset unless
1614		 * RX completed. It will stay set on the next tx.
1615		 */
1616		if (bus->wr_size)
1617			npcm_i2c_set_fifo(bus, -1, bus->wr_size);
1618		else
1619			npcm_i2c_set_fifo(bus, bus->rd_size, -1);
1620
1621		bus->state = I2C_OPER_STARTED;
1622
1623		if (npcm_i2c_is_quick(bus) || bus->wr_size)
1624			npcm_i2c_wr_byte(bus, bus->dest_addr);
1625		else
1626			npcm_i2c_wr_byte(bus, bus->dest_addr | BIT(0));
1627	/* SDA interrupt, after start\restart */
1628	} else {
1629		if (NPCM_I2CST_XMIT & i2cst) {
1630			bus->operation = I2C_WRITE_OPER;
1631			npcm_i2c_irq_master_handler_write(bus);
1632		} else {
1633			bus->operation = I2C_READ_OPER;
1634			npcm_i2c_irq_master_handler_read(bus);
1635		}
1636	}
1637}
1638
1639static int npcm_i2c_int_master_handler(struct npcm_i2c *bus)
1640{
1641	u8 i2cst;
1642	int ret = -EIO;
1643
1644	i2cst = ioread8(bus->reg + NPCM_I2CST);
1645
1646	if (FIELD_GET(NPCM_I2CST_NMATCH, i2cst)) {
1647		npcm_i2c_irq_handle_nmatch(bus);
1648		return 0;
1649	}
1650	/* A NACK has occurred */
1651	if (FIELD_GET(NPCM_I2CST_NEGACK, i2cst)) {
1652		npcm_i2c_irq_handle_nack(bus);
1653		return 0;
1654	}
1655
1656	/* Master mode: a Bus Error has been identified */
1657	if (FIELD_GET(NPCM_I2CST_BER, i2cst)) {
1658		npcm_i2c_irq_handle_ber(bus);
1659		return 0;
1660	}
1661
1662	/* EOB: a master End Of Busy (meaning STOP completed) */
1663	if ((FIELD_GET(NPCM_I2CCTL1_EOBINTE,
1664		       ioread8(bus->reg + NPCM_I2CCTL1)) == 1) &&
1665	    (FIELD_GET(NPCM_I2CCST3_EO_BUSY,
1666		       ioread8(bus->reg + NPCM_I2CCST3)))) {
1667		npcm_i2c_irq_handle_eob(bus);
1668		return 0;
1669	}
1670
1671	/* Address sent and requested stall occurred (Master mode) */
1672	if (FIELD_GET(NPCM_I2CST_STASTR, i2cst)) {
1673		npcm_i2c_irq_handle_stall_after_start(bus);
1674		ret = 0;
1675	}
1676
1677	/* SDA status is set - TX or RX, master */
1678	if (FIELD_GET(NPCM_I2CST_SDAST, i2cst) ||
1679	    (bus->fifo_use &&
1680	    (npcm_i2c_tx_fifo_empty(bus) || npcm_i2c_rx_fifo_full(bus)))) {
1681		npcm_i2c_irq_handle_sda(bus, i2cst);
1682		ret = 0;
1683	}
1684
1685	return ret;
1686}
1687
1688/* recovery using TGCLK functionality of the module */
1689static int npcm_i2c_recovery_tgclk(struct i2c_adapter *_adap)
1690{
1691	u8               val;
1692	u8               fif_cts;
1693	bool             done = false;
1694	int              status = -ENOTRECOVERABLE;
1695	struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
1696	/* Allow 3 bytes (27 toggles) to be read from the slave: */
1697	int              iter = 27;
1698
1699	if ((npcm_i2c_get_SDA(_adap) == 1) && (npcm_i2c_get_SCL(_adap) == 1)) {
1700		dev_dbg(bus->dev, "bus%d-0x%x recovery skipped, bus not stuck",
1701			bus->num, bus->dest_addr);
1702		npcm_i2c_reset(bus);
1703		return 0;
1704	}
1705
1706	npcm_i2c_int_enable(bus, false);
1707	npcm_i2c_disable(bus);
1708	npcm_i2c_enable(bus);
1709	iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
1710	npcm_i2c_clear_tx_fifo(bus);
1711	npcm_i2c_clear_rx_fifo(bus);
1712	iowrite8(0, bus->reg + NPCM_I2CRXF_CTL);
1713	iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
1714	npcm_i2c_stall_after_start(bus, false);
1715
1716	/* select bank 1 for FIFO regs */
1717	npcm_i2c_select_bank(bus, I2C_BANK_1);
1718
1719	/* clear FIFO and relevant status bits. */
1720	fif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS);
1721	fif_cts &= ~NPCM_I2CFIF_CTS_SLVRSTR;
1722	fif_cts |= NPCM_I2CFIF_CTS_CLR_FIFO;
1723	iowrite8(fif_cts, bus->reg + NPCM_I2CFIF_CTS);
1724	npcm_i2c_set_fifo(bus, -1, 0);
1725
1726	/* Repeat the following sequence until SDA is released */
1727	do {
1728		/* Issue a single SCL toggle */
1729		iowrite8(NPCM_I2CCST_TGSCL, bus->reg + NPCM_I2CCST);
1730		usleep_range(20, 30);
1731		/* If SDA line is inactive (high), stop */
1732		if (npcm_i2c_get_SDA(_adap)) {
1733			done = true;
1734			status = 0;
1735		}
1736	} while (!done && iter--);
1737
1738	/* If SDA line is released: send start-addr-stop, to re-sync. */
1739	if (npcm_i2c_get_SDA(_adap)) {
1740		/* Send an address byte in write direction: */
1741		npcm_i2c_wr_byte(bus, bus->dest_addr);
1742		npcm_i2c_master_start(bus);
1743		/* Wait until START condition is sent */
1744		status = readx_poll_timeout(npcm_i2c_get_SCL, _adap, val, !val,
1745					    20, 200);
1746		/* If START condition was sent */
1747		if (npcm_i2c_is_master(bus) > 0) {
1748			usleep_range(20, 30);
1749			npcm_i2c_master_stop(bus);
1750			usleep_range(200, 500);
1751		}
1752	}
1753	npcm_i2c_reset(bus);
1754	npcm_i2c_int_enable(bus, true);
1755
1756	if ((npcm_i2c_get_SDA(_adap) == 1) && (npcm_i2c_get_SCL(_adap) == 1))
1757		status = 0;
1758	else
1759		status = -ENOTRECOVERABLE;
1760	if (status) {
1761		if (bus->rec_fail_cnt < ULLONG_MAX)
1762			bus->rec_fail_cnt++;
1763	} else {
1764		if (bus->rec_succ_cnt < ULLONG_MAX)
1765			bus->rec_succ_cnt++;
1766	}
1767	return status;
1768}
1769
1770/* recovery using bit banging functionality of the module */
1771static void npcm_i2c_recovery_init(struct i2c_adapter *_adap)
1772{
1773	struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
1774	struct i2c_bus_recovery_info *rinfo = &bus->rinfo;
1775
1776	rinfo->recover_bus = npcm_i2c_recovery_tgclk;
1777
1778	/*
1779	 * npcm i2c HW allows direct reading of SCL and SDA.
1780	 * However, it does not support setting SCL and SDA directly.
1781	 * The recovery function can toggle SCL when SDA is low (but not set)
1782	 * Getter functions used internally, and can be used externally.
1783	 */
1784	rinfo->get_scl = npcm_i2c_get_SCL;
1785	rinfo->get_sda = npcm_i2c_get_SDA;
1786	_adap->bus_recovery_info = rinfo;
1787}
1788
1789/* SCLFRQ min/max field values */
1790#define SCLFRQ_MIN  10
1791#define SCLFRQ_MAX  511
1792#define clk_coef(freq, mul)	DIV_ROUND_UP((freq) * (mul), 1000000)
1793
1794/*
1795 * npcm_i2c_init_clk: init HW timing parameters.
1796 * NPCM7XX i2c module timing parameters are dependent on module core clk (APB)
1797 * and bus frequency.
1798 * 100kHz bus requires tSCL = 4 * SCLFRQ * tCLK. LT and HT are symmetric.
1799 * 400kHz bus requires asymmetric HT and LT. A different equation is recommended
1800 * by the HW designer, given core clock range (equations in comments below).
1801 *
1802 */
1803static int npcm_i2c_init_clk(struct npcm_i2c *bus, u32 bus_freq_hz)
1804{
1805	u32  k1 = 0;
1806	u32  k2 = 0;
1807	u8   dbnct = 0;
1808	u32  sclfrq = 0;
1809	u8   hldt = 7;
1810	u8   fast_mode = 0;
1811	u32  src_clk_khz;
1812	u32  bus_freq_khz;
1813
1814	src_clk_khz = bus->apb_clk / 1000;
1815	bus_freq_khz = bus_freq_hz / 1000;
1816	bus->bus_freq = bus_freq_hz;
1817
1818	/* 100KHz and below: */
1819	if (bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ) {
1820		sclfrq = src_clk_khz / (bus_freq_khz * 4);
1821
1822		if (sclfrq < SCLFRQ_MIN || sclfrq > SCLFRQ_MAX)
1823			return -EDOM;
1824
1825		if (src_clk_khz >= 40000)
1826			hldt = 17;
1827		else if (src_clk_khz >= 12500)
1828			hldt = 15;
1829		else
1830			hldt = 7;
1831	}
1832
1833	/* 400KHz: */
1834	else if (bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ) {
1835		sclfrq = 0;
1836		fast_mode = I2CCTL3_400K_MODE;
1837
1838		if (src_clk_khz < 7500)
1839			/* 400KHZ cannot be supported for core clock < 7.5MHz */
1840			return -EDOM;
1841
1842		else if (src_clk_khz >= 50000) {
1843			k1 = 80;
1844			k2 = 48;
1845			hldt = 12;
1846			dbnct = 7;
1847		}
1848
1849		/* Master or Slave with frequency > 25MHz */
1850		else if (src_clk_khz > 25000) {
1851			hldt = clk_coef(src_clk_khz, 300) + 7;
1852			k1 = clk_coef(src_clk_khz, 1600);
1853			k2 = clk_coef(src_clk_khz, 900);
1854		}
1855	}
1856
1857	/* 1MHz: */
1858	else if (bus_freq_hz <= I2C_MAX_FAST_MODE_PLUS_FREQ) {
1859		sclfrq = 0;
1860		fast_mode = I2CCTL3_400K_MODE;
1861
1862		/* 1MHZ cannot be supported for core clock < 24 MHz */
1863		if (src_clk_khz < 24000)
1864			return -EDOM;
1865
1866		k1 = clk_coef(src_clk_khz, 620);
1867		k2 = clk_coef(src_clk_khz, 380);
1868
1869		/* Core clk > 40 MHz */
1870		if (src_clk_khz > 40000) {
1871			/*
1872			 * Set HLDT:
1873			 * SDA hold time:  (HLDT-7) * T(CLK) >= 120
1874			 * HLDT = 120/T(CLK) + 7 = 120 * FREQ(CLK) + 7
1875			 */
1876			hldt = clk_coef(src_clk_khz, 120) + 7;
1877		} else {
1878			hldt = 7;
1879			dbnct = 2;
1880		}
1881	}
1882
1883	/* Frequency larger than 1 MHz is not supported */
1884	else
1885		return -EINVAL;
1886
1887	if (bus_freq_hz >= I2C_MAX_FAST_MODE_FREQ) {
1888		k1 = round_up(k1, 2);
1889		k2 = round_up(k2 + 1, 2);
1890		if (k1 < SCLFRQ_MIN || k1 > SCLFRQ_MAX ||
1891		    k2 < SCLFRQ_MIN || k2 > SCLFRQ_MAX)
1892			return -EDOM;
1893	}
1894
1895	/* write sclfrq value. bits [6:0] are in I2CCTL2 reg */
1896	iowrite8(FIELD_PREP(I2CCTL2_SCLFRQ6_0, sclfrq & 0x7F),
1897		 bus->reg + NPCM_I2CCTL2);
1898
1899	/* bits [8:7] are in I2CCTL3 reg */
1900	iowrite8(fast_mode | FIELD_PREP(I2CCTL3_SCLFRQ8_7, (sclfrq >> 7) & 0x3),
1901		 bus->reg + NPCM_I2CCTL3);
1902
1903	/* Select Bank 0 to access NPCM_I2CCTL4/NPCM_I2CCTL5 */
1904	npcm_i2c_select_bank(bus, I2C_BANK_0);
1905
1906	if (bus_freq_hz >= I2C_MAX_FAST_MODE_FREQ) {
1907		/*
1908		 * Set SCL Low/High Time:
1909		 * k1 = 2 * SCLLT7-0 -> Low Time  = k1 / 2
1910		 * k2 = 2 * SCLLT7-0 -> High Time = k2 / 2
1911		 */
1912		iowrite8(k1 / 2, bus->reg + NPCM_I2CSCLLT);
1913		iowrite8(k2 / 2, bus->reg + NPCM_I2CSCLHT);
1914
1915		iowrite8(dbnct, bus->reg + NPCM_I2CCTL5);
1916	}
1917
1918	iowrite8(hldt, bus->reg + NPCM_I2CCTL4);
1919
1920	/* Return to Bank 1, and stay there by default: */
1921	npcm_i2c_select_bank(bus, I2C_BANK_1);
1922
1923	return 0;
1924}
1925
1926static int npcm_i2c_init_module(struct npcm_i2c *bus, enum i2c_mode mode,
1927				u32 bus_freq_hz)
1928{
1929	u8 val;
1930	int ret;
1931
1932	/* Check whether module already enabled or frequency is out of bounds */
1933	if ((bus->state != I2C_DISABLE && bus->state != I2C_IDLE) ||
1934	    bus_freq_hz < I2C_FREQ_MIN_HZ || bus_freq_hz > I2C_FREQ_MAX_HZ)
1935		return -EINVAL;
1936
1937	npcm_i2c_int_enable(bus, false);
1938	npcm_i2c_disable(bus);
1939
1940	/* Configure FIFO mode : */
1941	if (FIELD_GET(I2C_VER_FIFO_EN, ioread8(bus->reg + I2C_VER))) {
1942		bus->fifo_use = true;
1943		npcm_i2c_select_bank(bus, I2C_BANK_0);
1944		val = ioread8(bus->reg + NPCM_I2CFIF_CTL);
1945		val |= NPCM_I2CFIF_CTL_FIFO_EN;
1946		iowrite8(val, bus->reg + NPCM_I2CFIF_CTL);
1947		npcm_i2c_select_bank(bus, I2C_BANK_1);
1948	} else {
1949		bus->fifo_use = false;
1950	}
1951
1952	/* Configure I2C module clock frequency */
1953	ret = npcm_i2c_init_clk(bus, bus_freq_hz);
1954	if (ret) {
1955		dev_err(bus->dev, "npcm_i2c_init_clk failed\n");
1956		return ret;
1957	}
1958
1959	/* Enable module (before configuring CTL1) */
1960	npcm_i2c_enable(bus);
1961	bus->state = I2C_IDLE;
1962	val = ioread8(bus->reg + NPCM_I2CCTL1);
1963	val = (val | NPCM_I2CCTL1_NMINTE) & ~NPCM_I2CCTL1_RWS;
1964	iowrite8(val, bus->reg + NPCM_I2CCTL1);
1965
1966	npcm_i2c_reset(bus);
1967
1968	/* Check HW is OK: SDA and SCL should be high at this point. */
1969	if ((npcm_i2c_get_SDA(&bus->adap) == 0) || (npcm_i2c_get_SCL(&bus->adap) == 0)) {
1970		dev_err(bus->dev, "I2C%d init fail: lines are low\n", bus->num);
1971		dev_err(bus->dev, "SDA=%d SCL=%d\n", npcm_i2c_get_SDA(&bus->adap),
1972			npcm_i2c_get_SCL(&bus->adap));
1973		return -ENXIO;
1974	}
1975
1976	npcm_i2c_int_enable(bus, true);
1977	return 0;
1978}
1979
1980static int __npcm_i2c_init(struct npcm_i2c *bus, struct platform_device *pdev)
1981{
1982	u32 clk_freq_hz;
1983	int ret;
1984
1985	/* Initialize the internal data structures */
1986	bus->state = I2C_DISABLE;
1987	bus->master_or_slave = I2C_SLAVE;
1988	bus->int_time_stamp = 0;
1989#if IS_ENABLED(CONFIG_I2C_SLAVE)
1990	bus->slave = NULL;
1991#endif
1992
1993	ret = device_property_read_u32(&pdev->dev, "clock-frequency",
1994				       &clk_freq_hz);
1995	if (ret) {
1996		dev_info(&pdev->dev, "Could not read clock-frequency property");
1997		clk_freq_hz = I2C_MAX_STANDARD_MODE_FREQ;
1998	}
1999
2000	ret = npcm_i2c_init_module(bus, I2C_MASTER, clk_freq_hz);
2001	if (ret) {
2002		dev_err(&pdev->dev, "npcm_i2c_init_module failed\n");
2003		return ret;
2004	}
2005
2006	return 0;
2007}
2008
2009static irqreturn_t npcm_i2c_bus_irq(int irq, void *dev_id)
2010{
2011	struct npcm_i2c *bus = dev_id;
2012
2013	if (npcm_i2c_is_master(bus))
2014		bus->master_or_slave = I2C_MASTER;
2015
2016	if (bus->master_or_slave == I2C_MASTER) {
2017		bus->int_time_stamp = jiffies;
2018		if (!npcm_i2c_int_master_handler(bus))
2019			return IRQ_HANDLED;
2020	}
2021#if IS_ENABLED(CONFIG_I2C_SLAVE)
2022	if (bus->slave) {
2023		bus->master_or_slave = I2C_SLAVE;
2024		if (npcm_i2c_int_slave_handler(bus))
2025			return IRQ_HANDLED;
2026	}
2027#endif
2028	/* Clear status bits for spurious interrupts */
2029	npcm_i2c_clear_master_status(bus);
2030
2031	return IRQ_HANDLED;
2032}
2033
2034static bool npcm_i2c_master_start_xmit(struct npcm_i2c *bus,
2035				       u8 slave_addr, u16 nwrite, u16 nread,
2036				       u8 *write_data, u8 *read_data,
2037				       bool use_PEC, bool use_read_block)
2038{
2039	if (bus->state != I2C_IDLE) {
2040		bus->cmd_err = -EBUSY;
2041		return false;
2042	}
2043	bus->dest_addr = slave_addr << 1;
2044	bus->wr_buf = write_data;
2045	bus->wr_size = nwrite;
2046	bus->wr_ind = 0;
2047	bus->rd_buf = read_data;
2048	bus->rd_size = nread;
2049	bus->rd_ind = 0;
2050	bus->PEC_use = 0;
2051
2052	/* for tx PEC is appended to buffer from i2c IF. PEC flag is ignored */
2053	if (nread)
2054		bus->PEC_use = use_PEC;
2055
2056	bus->read_block_use = use_read_block;
2057	if (nread && !nwrite)
2058		bus->operation = I2C_READ_OPER;
2059	else
2060		bus->operation = I2C_WRITE_OPER;
2061	if (bus->fifo_use) {
2062		u8 i2cfif_cts;
2063
2064		npcm_i2c_select_bank(bus, I2C_BANK_1);
2065		/* clear FIFO and relevant status bits. */
2066		i2cfif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS);
2067		i2cfif_cts &= ~NPCM_I2CFIF_CTS_SLVRSTR;
2068		i2cfif_cts |= NPCM_I2CFIF_CTS_CLR_FIFO;
2069		iowrite8(i2cfif_cts, bus->reg + NPCM_I2CFIF_CTS);
2070	}
2071
2072	bus->state = I2C_IDLE;
2073	npcm_i2c_stall_after_start(bus, true);
2074	npcm_i2c_master_start(bus);
2075	return true;
2076}
2077
2078static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
2079				int num)
2080{
2081	struct npcm_i2c *bus = container_of(adap, struct npcm_i2c, adap);
2082	struct i2c_msg *msg0, *msg1;
2083	unsigned long time_left, flags;
2084	u16 nwrite, nread;
2085	u8 *write_data, *read_data;
2086	u8 slave_addr;
2087	unsigned long timeout;
2088	bool read_block = false;
2089	bool read_PEC = false;
2090	u8 bus_busy;
2091	unsigned long timeout_usec;
2092
2093	if (bus->state == I2C_DISABLE) {
2094		dev_err(bus->dev, "I2C%d module is disabled", bus->num);
2095		return -EINVAL;
2096	}
2097
2098	msg0 = &msgs[0];
2099	slave_addr = msg0->addr;
2100	if (msg0->flags & I2C_M_RD) { /* read */
2101		nwrite = 0;
2102		write_data = NULL;
2103		read_data = msg0->buf;
2104		if (msg0->flags & I2C_M_RECV_LEN) {
2105			nread = 1;
2106			read_block = true;
2107			if (msg0->flags & I2C_CLIENT_PEC)
2108				read_PEC = true;
2109		} else {
2110			nread = msg0->len;
2111		}
2112	} else { /* write */
2113		nwrite = msg0->len;
2114		write_data = msg0->buf;
2115		nread = 0;
2116		read_data = NULL;
2117		if (num == 2) {
2118			msg1 = &msgs[1];
2119			read_data = msg1->buf;
2120			if (msg1->flags & I2C_M_RECV_LEN) {
2121				nread = 1;
2122				read_block = true;
2123				if (msg1->flags & I2C_CLIENT_PEC)
2124					read_PEC = true;
2125			} else {
2126				nread = msg1->len;
2127				read_block = false;
2128			}
2129		}
2130	}
2131
2132	/*
2133	 * Adaptive TimeOut: estimated time in usec + 100% margin:
2134	 * 2: double the timeout for clock stretching case
2135	 * 9: bits per transaction (including the ack/nack)
2136	 */
2137	timeout_usec = (2 * 9 * USEC_PER_SEC / bus->bus_freq) * (2 + nread + nwrite);
2138	timeout = max_t(unsigned long, bus->adap.timeout, usecs_to_jiffies(timeout_usec));
2139	if (nwrite >= 32 * 1024 || nread >= 32 * 1024) {
2140		dev_err(bus->dev, "i2c%d buffer too big\n", bus->num);
2141		return -EINVAL;
2142	}
2143
2144	time_left = jiffies + timeout + 1;
2145	do {
2146		/*
2147		 * we must clear slave address immediately when the bus is not
2148		 * busy, so we spinlock it, but we don't keep the lock for the
2149		 * entire while since it is too long.
2150		 */
2151		spin_lock_irqsave(&bus->lock, flags);
2152		bus_busy = ioread8(bus->reg + NPCM_I2CCST) & NPCM_I2CCST_BB;
2153#if IS_ENABLED(CONFIG_I2C_SLAVE)
2154		if (!bus_busy && bus->slave)
2155			iowrite8((bus->slave->addr & 0x7F),
2156				 bus->reg + NPCM_I2CADDR1);
2157#endif
2158		spin_unlock_irqrestore(&bus->lock, flags);
2159
2160	} while (time_is_after_jiffies(time_left) && bus_busy);
2161
2162	if (bus_busy) {
2163		iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
2164		npcm_i2c_reset(bus);
2165		i2c_recover_bus(adap);
2166		return -EAGAIN;
2167	}
2168
2169	npcm_i2c_init_params(bus);
2170	bus->dest_addr = slave_addr;
2171	bus->msgs = msgs;
2172	bus->msgs_num = num;
2173	bus->cmd_err = 0;
2174	bus->read_block_use = read_block;
2175
2176	reinit_completion(&bus->cmd_complete);
2177
2178	npcm_i2c_int_enable(bus, true);
2179
2180	if (npcm_i2c_master_start_xmit(bus, slave_addr, nwrite, nread,
2181				       write_data, read_data, read_PEC,
2182				       read_block)) {
2183		time_left = wait_for_completion_timeout(&bus->cmd_complete,
2184							timeout);
2185
2186		if (time_left == 0) {
2187			if (bus->timeout_cnt < ULLONG_MAX)
2188				bus->timeout_cnt++;
2189			if (bus->master_or_slave == I2C_MASTER) {
2190				i2c_recover_bus(adap);
2191				bus->cmd_err = -EIO;
2192				bus->state = I2C_IDLE;
2193			}
2194		}
2195	}
2196
2197	/* if there was BER, check if need to recover the bus: */
2198	if (bus->cmd_err == -EAGAIN)
2199		bus->cmd_err = i2c_recover_bus(adap);
2200
2201	/*
2202	 * After any type of error, check if LAST bit is still set,
2203	 * due to a HW issue.
2204	 * It cannot be cleared without resetting the module.
2205	 */
2206	else if (bus->cmd_err &&
2207		 (bus->data->rxf_ctl_last_pec & ioread8(bus->reg + NPCM_I2CRXF_CTL)))
2208		npcm_i2c_reset(bus);
2209
2210	/* After any xfer, successful or not, stall and EOB must be disabled */
2211	npcm_i2c_stall_after_start(bus, false);
2212	npcm_i2c_eob_int(bus, false);
2213
2214#if IS_ENABLED(CONFIG_I2C_SLAVE)
2215	/* reenable slave if it was enabled */
2216	if (bus->slave)
2217		iowrite8((bus->slave->addr & 0x7F) | NPCM_I2CADDR_SAEN,
2218			 bus->reg + NPCM_I2CADDR1);
2219#else
2220	npcm_i2c_int_enable(bus, false);
2221#endif
2222	return bus->cmd_err;
2223}
2224
2225static u32 npcm_i2c_functionality(struct i2c_adapter *adap)
2226{
2227	return I2C_FUNC_I2C |
2228	       I2C_FUNC_SMBUS_EMUL |
2229	       I2C_FUNC_SMBUS_BLOCK_DATA |
2230	       I2C_FUNC_SMBUS_PEC |
2231	       I2C_FUNC_SLAVE;
2232}
2233
2234static const struct i2c_adapter_quirks npcm_i2c_quirks = {
2235	.max_read_len = 32768,
2236	.max_write_len = 32768,
2237	.flags = I2C_AQ_COMB_WRITE_THEN_READ,
2238};
2239
2240static const struct i2c_algorithm npcm_i2c_algo = {
2241	.master_xfer = npcm_i2c_master_xfer,
2242	.functionality = npcm_i2c_functionality,
2243#if IS_ENABLED(CONFIG_I2C_SLAVE)
2244	.reg_slave	= npcm_i2c_reg_slave,
2245	.unreg_slave	= npcm_i2c_unreg_slave,
2246#endif
2247};
2248
2249static void npcm_i2c_init_debugfs(struct platform_device *pdev,
2250				  struct npcm_i2c *bus)
2251{
2252	debugfs_create_u64("ber_cnt", 0444, bus->adap.debugfs, &bus->ber_cnt);
2253	debugfs_create_u64("nack_cnt", 0444, bus->adap.debugfs, &bus->nack_cnt);
2254	debugfs_create_u64("rec_succ_cnt", 0444, bus->adap.debugfs, &bus->rec_succ_cnt);
2255	debugfs_create_u64("rec_fail_cnt", 0444, bus->adap.debugfs, &bus->rec_fail_cnt);
2256	debugfs_create_u64("timeout_cnt", 0444, bus->adap.debugfs, &bus->timeout_cnt);
2257	debugfs_create_u64("tx_complete_cnt", 0444, bus->adap.debugfs, &bus->tx_complete_cnt);
2258}
2259
2260static int npcm_i2c_probe_bus(struct platform_device *pdev)
2261{
2262	struct device_node *np = pdev->dev.of_node;
2263	static struct regmap *gcr_regmap;
2264	struct device *dev = &pdev->dev;
2265	struct i2c_adapter *adap;
2266	struct npcm_i2c *bus;
2267	struct clk *i2c_clk;
2268	int irq;
2269	int ret;
2270
2271	bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
2272	if (!bus)
2273		return -ENOMEM;
2274
2275	bus->dev = &pdev->dev;
2276
2277	bus->data = of_device_get_match_data(dev);
2278	if (!bus->data) {
2279		dev_err(dev, "OF data missing\n");
2280		return -EINVAL;
2281	}
2282
2283	bus->num = of_alias_get_id(pdev->dev.of_node, "i2c");
2284	/* core clk must be acquired to calculate module timing settings */
2285	i2c_clk = devm_clk_get(&pdev->dev, NULL);
2286	if (IS_ERR(i2c_clk))
2287		return PTR_ERR(i2c_clk);
2288	bus->apb_clk = clk_get_rate(i2c_clk);
2289
2290	gcr_regmap = syscon_regmap_lookup_by_phandle(np, "nuvoton,sys-mgr");
2291	if (IS_ERR(gcr_regmap))
2292		gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
2293
2294	if (IS_ERR(gcr_regmap))
2295		return PTR_ERR(gcr_regmap);
2296	regmap_write(gcr_regmap, NPCM_I2CSEGCTL, bus->data->segctl_init_val);
2297
2298	bus->reg = devm_platform_ioremap_resource(pdev, 0);
2299	if (IS_ERR(bus->reg))
2300		return PTR_ERR(bus->reg);
2301
2302	spin_lock_init(&bus->lock);
2303	init_completion(&bus->cmd_complete);
2304
2305	adap = &bus->adap;
2306	adap->owner = THIS_MODULE;
2307	adap->retries = 3;
2308	adap->timeout = msecs_to_jiffies(35);
2309	adap->algo = &npcm_i2c_algo;
2310	adap->quirks = &npcm_i2c_quirks;
2311	adap->algo_data = bus;
2312	adap->dev.parent = &pdev->dev;
2313	adap->dev.of_node = pdev->dev.of_node;
2314	adap->nr = pdev->id;
2315
2316	irq = platform_get_irq(pdev, 0);
2317	if (irq < 0)
2318		return irq;
2319
2320	ret = devm_request_irq(bus->dev, irq, npcm_i2c_bus_irq, 0,
2321			       dev_name(bus->dev), bus);
2322	if (ret)
2323		return ret;
2324
2325	ret = __npcm_i2c_init(bus, pdev);
2326	if (ret)
2327		return ret;
2328
2329	npcm_i2c_recovery_init(adap);
2330
2331	i2c_set_adapdata(adap, bus);
2332
2333	snprintf(bus->adap.name, sizeof(bus->adap.name), "npcm_i2c_%d",
2334		 bus->num);
2335	ret = i2c_add_numbered_adapter(&bus->adap);
2336	if (ret)
2337		return ret;
2338
2339	platform_set_drvdata(pdev, bus);
2340	npcm_i2c_init_debugfs(pdev, bus);
2341	return 0;
2342}
2343
2344static void npcm_i2c_remove_bus(struct platform_device *pdev)
2345{
2346	unsigned long lock_flags;
2347	struct npcm_i2c *bus = platform_get_drvdata(pdev);
2348
2349	spin_lock_irqsave(&bus->lock, lock_flags);
2350	npcm_i2c_disable(bus);
2351	spin_unlock_irqrestore(&bus->lock, lock_flags);
2352	i2c_del_adapter(&bus->adap);
2353}
2354
2355static const struct of_device_id npcm_i2c_bus_of_table[] = {
2356	{ .compatible = "nuvoton,npcm750-i2c", .data = &npxm7xx_i2c_data },
2357	{ .compatible = "nuvoton,npcm845-i2c", .data = &npxm8xx_i2c_data },
2358	{}
2359};
2360MODULE_DEVICE_TABLE(of, npcm_i2c_bus_of_table);
2361
2362static struct platform_driver npcm_i2c_bus_driver = {
2363	.probe = npcm_i2c_probe_bus,
2364	.remove_new = npcm_i2c_remove_bus,
2365	.driver = {
2366		.name = "nuvoton-i2c",
2367		.of_match_table = npcm_i2c_bus_of_table,
2368	}
2369};
2370
2371module_platform_driver(npcm_i2c_bus_driver);
2372
2373MODULE_AUTHOR("Avi Fishman <avi.fishman@gmail.com>");
2374MODULE_AUTHOR("Tali Perry <tali.perry@nuvoton.com>");
2375MODULE_AUTHOR("Tyrone Ting <kfting@nuvoton.com>");
2376MODULE_DESCRIPTION("Nuvoton I2C Bus Driver");
2377MODULE_LICENSE("GPL v2");
2378