1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2015-2018, Intel Corporation.
4 */
5
6#define pr_fmt(fmt) "aspeed-kcs-bmc: " fmt
7
8#include <linux/atomic.h>
9#include <linux/errno.h>
10#include <linux/interrupt.h>
11#include <linux/io.h>
12#include <linux/irq.h>
13#include <linux/mfd/syscon.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/of_address.h>
17#include <linux/platform_device.h>
18#include <linux/poll.h>
19#include <linux/regmap.h>
20#include <linux/sched.h>
21#include <linux/slab.h>
22#include <linux/timer.h>
23
24#include "kcs_bmc_device.h"
25
26
27#define DEVICE_NAME     "ast-kcs-bmc"
28
29#define KCS_CHANNEL_MAX     4
30
31/*
32 * Field class descriptions
33 *
34 * LPCyE	Enable LPC channel y
35 * IBFIEy	Input Buffer Full IRQ Enable for LPC channel y
36 * IRQxEy	Assert SerIRQ x for LPC channel y (Deprecated, use IDyIRQX, IRQXEy)
37 * IDyIRQX	Use the specified 4-bit SerIRQ for LPC channel y
38 * SELyIRQX	SerIRQ polarity for LPC channel y (low: 0, high: 1)
39 * IRQXEy	Assert the SerIRQ specified in IDyIRQX for LPC channel y
40 */
41
42#define LPC_TYIRQX_LOW       0b00
43#define LPC_TYIRQX_HIGH      0b01
44#define LPC_TYIRQX_RSVD      0b10
45#define LPC_TYIRQX_RISING    0b11
46
47#define LPC_HICR0            0x000
48#define     LPC_HICR0_LPC3E          BIT(7)
49#define     LPC_HICR0_LPC2E          BIT(6)
50#define     LPC_HICR0_LPC1E          BIT(5)
51#define LPC_HICR2            0x008
52#define     LPC_HICR2_IBFIE3         BIT(3)
53#define     LPC_HICR2_IBFIE2         BIT(2)
54#define     LPC_HICR2_IBFIE1         BIT(1)
55#define LPC_HICR4            0x010
56#define     LPC_HICR4_LADR12AS       BIT(7)
57#define     LPC_HICR4_KCSENBL        BIT(2)
58#define LPC_SIRQCR0	     0x070
59/* IRQ{12,1}E1 are deprecated as of AST2600 A3 but necessary for prior chips */
60#define     LPC_SIRQCR0_IRQ12E1	     BIT(1)
61#define     LPC_SIRQCR0_IRQ1E1	     BIT(0)
62#define LPC_HICR5	     0x080
63#define     LPC_HICR5_ID3IRQX_MASK   GENMASK(23, 20)
64#define     LPC_HICR5_ID3IRQX_SHIFT  20
65#define     LPC_HICR5_ID2IRQX_MASK   GENMASK(19, 16)
66#define     LPC_HICR5_ID2IRQX_SHIFT  16
67#define     LPC_HICR5_SEL3IRQX       BIT(15)
68#define     LPC_HICR5_IRQXE3         BIT(14)
69#define     LPC_HICR5_SEL2IRQX       BIT(13)
70#define     LPC_HICR5_IRQXE2         BIT(12)
71#define LPC_LADR3H           0x014
72#define LPC_LADR3L           0x018
73#define LPC_LADR12H          0x01C
74#define LPC_LADR12L          0x020
75#define LPC_IDR1             0x024
76#define LPC_IDR2             0x028
77#define LPC_IDR3             0x02C
78#define LPC_ODR1             0x030
79#define LPC_ODR2             0x034
80#define LPC_ODR3             0x038
81#define LPC_STR1             0x03C
82#define LPC_STR2             0x040
83#define LPC_STR3             0x044
84#define LPC_HICRB            0x100
85#define     LPC_HICRB_EN16LADR2      BIT(5)
86#define     LPC_HICRB_EN16LADR1      BIT(4)
87#define     LPC_HICRB_IBFIE4         BIT(1)
88#define     LPC_HICRB_LPC4E          BIT(0)
89#define LPC_HICRC            0x104
90#define     LPC_HICRC_ID4IRQX_MASK   GENMASK(7, 4)
91#define     LPC_HICRC_ID4IRQX_SHIFT  4
92#define     LPC_HICRC_TY4IRQX_MASK   GENMASK(3, 2)
93#define     LPC_HICRC_TY4IRQX_SHIFT  2
94#define     LPC_HICRC_OBF4_AUTO_CLR  BIT(1)
95#define     LPC_HICRC_IRQXE4         BIT(0)
96#define LPC_LADR4            0x110
97#define LPC_IDR4             0x114
98#define LPC_ODR4             0x118
99#define LPC_STR4             0x11C
100#define LPC_LSADR12	     0x120
101#define     LPC_LSADR12_LSADR2_MASK  GENMASK(31, 16)
102#define     LPC_LSADR12_LSADR2_SHIFT 16
103#define     LPC_LSADR12_LSADR1_MASK  GENMASK(15, 0)
104#define     LPC_LSADR12_LSADR1_SHIFT 0
105
106#define OBE_POLL_PERIOD	     (HZ / 2)
107
108enum aspeed_kcs_irq_mode {
109	aspeed_kcs_irq_none,
110	aspeed_kcs_irq_serirq,
111};
112
113struct aspeed_kcs_bmc {
114	struct kcs_bmc_device kcs_bmc;
115
116	struct regmap *map;
117
118	struct {
119		enum aspeed_kcs_irq_mode mode;
120		int id;
121	} upstream_irq;
122
123	struct {
124		spinlock_t lock;
125		bool remove;
126		struct timer_list timer;
127	} obe;
128};
129
130static inline struct aspeed_kcs_bmc *to_aspeed_kcs_bmc(struct kcs_bmc_device *kcs_bmc)
131{
132	return container_of(kcs_bmc, struct aspeed_kcs_bmc, kcs_bmc);
133}
134
135static u8 aspeed_kcs_inb(struct kcs_bmc_device *kcs_bmc, u32 reg)
136{
137	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
138	u32 val = 0;
139	int rc;
140
141	rc = regmap_read(priv->map, reg, &val);
142	WARN(rc != 0, "regmap_read() failed: %d\n", rc);
143
144	return rc == 0 ? (u8) val : 0;
145}
146
147static void aspeed_kcs_outb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 data)
148{
149	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
150	int rc;
151
152	rc = regmap_write(priv->map, reg, data);
153	WARN(rc != 0, "regmap_write() failed: %d\n", rc);
154
155	/* Trigger the upstream IRQ on ODR writes, if enabled */
156
157	switch (reg) {
158	case LPC_ODR1:
159	case LPC_ODR2:
160	case LPC_ODR3:
161	case LPC_ODR4:
162		break;
163	default:
164		return;
165	}
166
167	if (priv->upstream_irq.mode != aspeed_kcs_irq_serirq)
168		return;
169
170	switch (kcs_bmc->channel) {
171	case 1:
172		switch (priv->upstream_irq.id) {
173		case 12:
174			regmap_update_bits(priv->map, LPC_SIRQCR0, LPC_SIRQCR0_IRQ12E1,
175					   LPC_SIRQCR0_IRQ12E1);
176			break;
177		case 1:
178			regmap_update_bits(priv->map, LPC_SIRQCR0, LPC_SIRQCR0_IRQ1E1,
179					   LPC_SIRQCR0_IRQ1E1);
180			break;
181		default:
182			break;
183		}
184		break;
185	case 2:
186		regmap_update_bits(priv->map, LPC_HICR5, LPC_HICR5_IRQXE2, LPC_HICR5_IRQXE2);
187		break;
188	case 3:
189		regmap_update_bits(priv->map, LPC_HICR5, LPC_HICR5_IRQXE3, LPC_HICR5_IRQXE3);
190		break;
191	case 4:
192		regmap_update_bits(priv->map, LPC_HICRC, LPC_HICRC_IRQXE4, LPC_HICRC_IRQXE4);
193		break;
194	default:
195		break;
196	}
197}
198
199static void aspeed_kcs_updateb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 mask, u8 val)
200{
201	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
202	int rc;
203
204	rc = regmap_update_bits(priv->map, reg, mask, val);
205	WARN(rc != 0, "regmap_update_bits() failed: %d\n", rc);
206}
207
208/*
209 * We note D for Data, and C for Cmd/Status, default rules are
210 *
211 * 1. Only the D address is given:
212 *   A. KCS1/KCS2 (D/C: X/X+4)
213 *      D/C: CA0h/CA4h
214 *      D/C: CA8h/CACh
215 *   B. KCS3 (D/C: XX2/XX3h)
216 *      D/C: CA2h/CA3h
217 *   C. KCS4 (D/C: X/X+1)
218 *      D/C: CA4h/CA5h
219 *
220 * 2. Both the D/C addresses are given:
221 *   A. KCS1/KCS2/KCS4 (D/C: X/Y)
222 *      D/C: CA0h/CA1h
223 *      D/C: CA8h/CA9h
224 *      D/C: CA4h/CA5h
225 *   B. KCS3 (D/C: XX2/XX3h)
226 *      D/C: CA2h/CA3h
227 */
228static int aspeed_kcs_set_address(struct kcs_bmc_device *kcs_bmc, u32 addrs[2], int nr_addrs)
229{
230	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
231
232	if (WARN_ON(nr_addrs < 1 || nr_addrs > 2))
233		return -EINVAL;
234
235	switch (priv->kcs_bmc.channel) {
236	case 1:
237		regmap_update_bits(priv->map, LPC_HICR4, LPC_HICR4_LADR12AS, 0);
238		regmap_write(priv->map, LPC_LADR12H, addrs[0] >> 8);
239		regmap_write(priv->map, LPC_LADR12L, addrs[0] & 0xFF);
240		if (nr_addrs == 2) {
241			regmap_update_bits(priv->map, LPC_LSADR12, LPC_LSADR12_LSADR1_MASK,
242					   addrs[1] << LPC_LSADR12_LSADR1_SHIFT);
243
244			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_EN16LADR1,
245					   LPC_HICRB_EN16LADR1);
246		}
247		break;
248
249	case 2:
250		regmap_update_bits(priv->map, LPC_HICR4, LPC_HICR4_LADR12AS, LPC_HICR4_LADR12AS);
251		regmap_write(priv->map, LPC_LADR12H, addrs[0] >> 8);
252		regmap_write(priv->map, LPC_LADR12L, addrs[0] & 0xFF);
253		if (nr_addrs == 2) {
254			regmap_update_bits(priv->map, LPC_LSADR12, LPC_LSADR12_LSADR2_MASK,
255					   addrs[1] << LPC_LSADR12_LSADR2_SHIFT);
256
257			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_EN16LADR2,
258					   LPC_HICRB_EN16LADR2);
259		}
260		break;
261
262	case 3:
263		if (nr_addrs == 2) {
264			dev_err(priv->kcs_bmc.dev,
265				"Channel 3 only supports inferred status IO address\n");
266			return -EINVAL;
267		}
268
269		regmap_write(priv->map, LPC_LADR3H, addrs[0] >> 8);
270		regmap_write(priv->map, LPC_LADR3L, addrs[0] & 0xFF);
271		break;
272
273	case 4:
274		if (nr_addrs == 1)
275			regmap_write(priv->map, LPC_LADR4, ((addrs[0] + 1) << 16) | addrs[0]);
276		else
277			regmap_write(priv->map, LPC_LADR4, (addrs[1] << 16) | addrs[0]);
278
279		break;
280
281	default:
282		return -EINVAL;
283	}
284
285	return 0;
286}
287
288static inline int aspeed_kcs_map_serirq_type(u32 dt_type)
289{
290	switch (dt_type) {
291	case IRQ_TYPE_EDGE_RISING:
292		return LPC_TYIRQX_RISING;
293	case IRQ_TYPE_LEVEL_HIGH:
294		return LPC_TYIRQX_HIGH;
295	case IRQ_TYPE_LEVEL_LOW:
296		return LPC_TYIRQX_LOW;
297	default:
298		return -EINVAL;
299	}
300}
301
302static int aspeed_kcs_config_upstream_irq(struct aspeed_kcs_bmc *priv, u32 id, u32 dt_type)
303{
304	unsigned int mask, val, hw_type;
305	int ret;
306
307	if (id > 15)
308		return -EINVAL;
309
310	ret = aspeed_kcs_map_serirq_type(dt_type);
311	if (ret < 0)
312		return ret;
313	hw_type = ret;
314
315	priv->upstream_irq.mode = aspeed_kcs_irq_serirq;
316	priv->upstream_irq.id = id;
317
318	switch (priv->kcs_bmc.channel) {
319	case 1:
320		/* Needs IRQxE1 rather than (ID1IRQX, SEL1IRQX, IRQXE1) before AST2600 A3 */
321		break;
322	case 2:
323		if (!(hw_type == LPC_TYIRQX_LOW || hw_type == LPC_TYIRQX_HIGH))
324			return -EINVAL;
325
326		mask = LPC_HICR5_SEL2IRQX | LPC_HICR5_ID2IRQX_MASK;
327		val = (id << LPC_HICR5_ID2IRQX_SHIFT);
328		val |= (hw_type == LPC_TYIRQX_HIGH) ? LPC_HICR5_SEL2IRQX : 0;
329		regmap_update_bits(priv->map, LPC_HICR5, mask, val);
330
331		break;
332	case 3:
333		if (!(hw_type == LPC_TYIRQX_LOW || hw_type == LPC_TYIRQX_HIGH))
334			return -EINVAL;
335
336		mask = LPC_HICR5_SEL3IRQX | LPC_HICR5_ID3IRQX_MASK;
337		val = (id << LPC_HICR5_ID3IRQX_SHIFT);
338		val |= (hw_type == LPC_TYIRQX_HIGH) ? LPC_HICR5_SEL3IRQX : 0;
339		regmap_update_bits(priv->map, LPC_HICR5, mask, val);
340
341		break;
342	case 4:
343		mask = LPC_HICRC_ID4IRQX_MASK | LPC_HICRC_TY4IRQX_MASK | LPC_HICRC_OBF4_AUTO_CLR;
344		val = (id << LPC_HICRC_ID4IRQX_SHIFT) | (hw_type << LPC_HICRC_TY4IRQX_SHIFT);
345		regmap_update_bits(priv->map, LPC_HICRC, mask, val);
346		break;
347	default:
348		dev_warn(priv->kcs_bmc.dev,
349			 "SerIRQ configuration not supported on KCS channel %d\n",
350			 priv->kcs_bmc.channel);
351		return -EINVAL;
352	}
353
354	return 0;
355}
356
357static void aspeed_kcs_enable_channel(struct kcs_bmc_device *kcs_bmc, bool enable)
358{
359	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
360
361	switch (kcs_bmc->channel) {
362	case 1:
363		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC1E, enable * LPC_HICR0_LPC1E);
364		return;
365	case 2:
366		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC2E, enable * LPC_HICR0_LPC2E);
367		return;
368	case 3:
369		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC3E, enable * LPC_HICR0_LPC3E);
370		regmap_update_bits(priv->map, LPC_HICR4,
371				   LPC_HICR4_KCSENBL, enable * LPC_HICR4_KCSENBL);
372		return;
373	case 4:
374		regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_LPC4E, enable * LPC_HICRB_LPC4E);
375		return;
376	default:
377		pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel);
378		return;
379	}
380}
381
382static void aspeed_kcs_check_obe(struct timer_list *timer)
383{
384	struct aspeed_kcs_bmc *priv = container_of(timer, struct aspeed_kcs_bmc, obe.timer);
385	unsigned long flags;
386	u8 str;
387
388	spin_lock_irqsave(&priv->obe.lock, flags);
389	if (priv->obe.remove) {
390		spin_unlock_irqrestore(&priv->obe.lock, flags);
391		return;
392	}
393
394	str = aspeed_kcs_inb(&priv->kcs_bmc, priv->kcs_bmc.ioreg.str);
395	if (str & KCS_BMC_STR_OBF) {
396		mod_timer(timer, jiffies + OBE_POLL_PERIOD);
397		spin_unlock_irqrestore(&priv->obe.lock, flags);
398		return;
399	}
400	spin_unlock_irqrestore(&priv->obe.lock, flags);
401
402	kcs_bmc_handle_event(&priv->kcs_bmc);
403}
404
405static void aspeed_kcs_irq_mask_update(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 state)
406{
407	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
408	int rc;
409	u8 str;
410
411	/* We don't have an OBE IRQ, emulate it */
412	if (mask & KCS_BMC_EVENT_TYPE_OBE) {
413		if (KCS_BMC_EVENT_TYPE_OBE & state) {
414			/*
415			 * Given we don't have an OBE IRQ, delay by polling briefly to see if we can
416			 * observe such an event before returning to the caller. This is not
417			 * incorrect because OBF may have already become clear before enabling the
418			 * IRQ if we had one, under which circumstance no event will be propagated
419			 * anyway.
420			 *
421			 * The onus is on the client to perform a race-free check that it hasn't
422			 * missed the event.
423			 */
424			rc = read_poll_timeout_atomic(aspeed_kcs_inb, str,
425						      !(str & KCS_BMC_STR_OBF), 1, 100, false,
426						      &priv->kcs_bmc, priv->kcs_bmc.ioreg.str);
427			/* Time for the slow path? */
428			if (rc == -ETIMEDOUT)
429				mod_timer(&priv->obe.timer, jiffies + OBE_POLL_PERIOD);
430		} else {
431			del_timer(&priv->obe.timer);
432		}
433	}
434
435	if (mask & KCS_BMC_EVENT_TYPE_IBF) {
436		const bool enable = !!(state & KCS_BMC_EVENT_TYPE_IBF);
437
438		switch (kcs_bmc->channel) {
439		case 1:
440			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE1,
441					   enable * LPC_HICR2_IBFIE1);
442			return;
443		case 2:
444			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE2,
445					   enable * LPC_HICR2_IBFIE2);
446			return;
447		case 3:
448			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE3,
449					   enable * LPC_HICR2_IBFIE3);
450			return;
451		case 4:
452			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_IBFIE4,
453					   enable * LPC_HICRB_IBFIE4);
454			return;
455		default:
456			pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel);
457			return;
458		}
459	}
460}
461
462static const struct kcs_bmc_device_ops aspeed_kcs_ops = {
463	.irq_mask_update = aspeed_kcs_irq_mask_update,
464	.io_inputb = aspeed_kcs_inb,
465	.io_outputb = aspeed_kcs_outb,
466	.io_updateb = aspeed_kcs_updateb,
467};
468
469static irqreturn_t aspeed_kcs_irq(int irq, void *arg)
470{
471	struct kcs_bmc_device *kcs_bmc = arg;
472
473	return kcs_bmc_handle_event(kcs_bmc);
474}
475
476static int aspeed_kcs_config_downstream_irq(struct kcs_bmc_device *kcs_bmc,
477			struct platform_device *pdev)
478{
479	struct device *dev = &pdev->dev;
480	int irq;
481
482	irq = platform_get_irq(pdev, 0);
483	if (irq < 0)
484		return irq;
485
486	return devm_request_irq(dev, irq, aspeed_kcs_irq, IRQF_SHARED,
487				dev_name(dev), kcs_bmc);
488}
489
490static const struct kcs_ioreg ast_kcs_bmc_ioregs[KCS_CHANNEL_MAX] = {
491	{ .idr = LPC_IDR1, .odr = LPC_ODR1, .str = LPC_STR1 },
492	{ .idr = LPC_IDR2, .odr = LPC_ODR2, .str = LPC_STR2 },
493	{ .idr = LPC_IDR3, .odr = LPC_ODR3, .str = LPC_STR3 },
494	{ .idr = LPC_IDR4, .odr = LPC_ODR4, .str = LPC_STR4 },
495};
496
497static int aspeed_kcs_of_get_channel(struct platform_device *pdev)
498{
499	struct device_node *np;
500	struct kcs_ioreg ioreg;
501	const __be32 *reg;
502	int i;
503
504	np = pdev->dev.of_node;
505
506	/* Don't translate addresses, we want offsets for the regmaps */
507	reg = of_get_address(np, 0, NULL, NULL);
508	if (!reg)
509		return -EINVAL;
510	ioreg.idr = be32_to_cpup(reg);
511
512	reg = of_get_address(np, 1, NULL, NULL);
513	if (!reg)
514		return -EINVAL;
515	ioreg.odr = be32_to_cpup(reg);
516
517	reg = of_get_address(np, 2, NULL, NULL);
518	if (!reg)
519		return -EINVAL;
520	ioreg.str = be32_to_cpup(reg);
521
522	for (i = 0; i < ARRAY_SIZE(ast_kcs_bmc_ioregs); i++) {
523		if (!memcmp(&ast_kcs_bmc_ioregs[i], &ioreg, sizeof(ioreg)))
524			return i + 1;
525	}
526	return -EINVAL;
527}
528
529static int
530aspeed_kcs_of_get_io_address(struct platform_device *pdev, u32 addrs[2])
531{
532	int rc;
533
534	rc = of_property_read_variable_u32_array(pdev->dev.of_node,
535						 "aspeed,lpc-io-reg",
536						 addrs, 1, 2);
537	if (rc < 0) {
538		dev_err(&pdev->dev, "No valid 'aspeed,lpc-io-reg' configured\n");
539		return rc;
540	}
541
542	if (addrs[0] > 0xffff) {
543		dev_err(&pdev->dev, "Invalid data address in 'aspeed,lpc-io-reg'\n");
544		return -EINVAL;
545	}
546
547	if (rc == 2 && addrs[1] > 0xffff) {
548		dev_err(&pdev->dev, "Invalid status address in 'aspeed,lpc-io-reg'\n");
549		return -EINVAL;
550	}
551
552	return rc;
553}
554
555static int aspeed_kcs_probe(struct platform_device *pdev)
556{
557	struct kcs_bmc_device *kcs_bmc;
558	struct aspeed_kcs_bmc *priv;
559	struct device_node *np;
560	bool have_upstream_irq;
561	u32 upstream_irq[2];
562	int rc, channel;
563	int nr_addrs;
564	u32 addrs[2];
565
566	np = pdev->dev.of_node->parent;
567	if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") &&
568	    !of_device_is_compatible(np, "aspeed,ast2500-lpc-v2") &&
569	    !of_device_is_compatible(np, "aspeed,ast2600-lpc-v2")) {
570		dev_err(&pdev->dev, "unsupported LPC device binding\n");
571		return -ENODEV;
572	}
573
574	channel = aspeed_kcs_of_get_channel(pdev);
575	if (channel < 0)
576		return channel;
577
578	nr_addrs = aspeed_kcs_of_get_io_address(pdev, addrs);
579	if (nr_addrs < 0)
580		return nr_addrs;
581
582	np = pdev->dev.of_node;
583	rc = of_property_read_u32_array(np, "aspeed,lpc-interrupts", upstream_irq, 2);
584	if (rc && rc != -EINVAL)
585		return -EINVAL;
586
587	have_upstream_irq = !rc;
588
589	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
590	if (!priv)
591		return -ENOMEM;
592
593	kcs_bmc = &priv->kcs_bmc;
594	kcs_bmc->dev = &pdev->dev;
595	kcs_bmc->channel = channel;
596	kcs_bmc->ioreg = ast_kcs_bmc_ioregs[channel - 1];
597	kcs_bmc->ops = &aspeed_kcs_ops;
598
599	priv->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
600	if (IS_ERR(priv->map)) {
601		dev_err(&pdev->dev, "Couldn't get regmap\n");
602		return -ENODEV;
603	}
604
605	spin_lock_init(&priv->obe.lock);
606	priv->obe.remove = false;
607	timer_setup(&priv->obe.timer, aspeed_kcs_check_obe, 0);
608
609	rc = aspeed_kcs_set_address(kcs_bmc, addrs, nr_addrs);
610	if (rc)
611		return rc;
612
613	/* Host to BMC IRQ */
614	rc = aspeed_kcs_config_downstream_irq(kcs_bmc, pdev);
615	if (rc)
616		return rc;
617
618	/* BMC to Host IRQ */
619	if (have_upstream_irq) {
620		rc = aspeed_kcs_config_upstream_irq(priv, upstream_irq[0], upstream_irq[1]);
621		if (rc < 0)
622			return rc;
623	} else {
624		priv->upstream_irq.mode = aspeed_kcs_irq_none;
625	}
626
627	platform_set_drvdata(pdev, priv);
628
629	aspeed_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
630	aspeed_kcs_enable_channel(kcs_bmc, true);
631
632	rc = kcs_bmc_add_device(&priv->kcs_bmc);
633	if (rc) {
634		dev_warn(&pdev->dev, "Failed to register channel %d: %d\n", kcs_bmc->channel, rc);
635		return rc;
636	}
637
638	dev_info(&pdev->dev, "Initialised channel %d at 0x%x\n",
639			kcs_bmc->channel, addrs[0]);
640
641	return 0;
642}
643
644static int aspeed_kcs_remove(struct platform_device *pdev)
645{
646	struct aspeed_kcs_bmc *priv = platform_get_drvdata(pdev);
647	struct kcs_bmc_device *kcs_bmc = &priv->kcs_bmc;
648
649	kcs_bmc_remove_device(kcs_bmc);
650
651	aspeed_kcs_enable_channel(kcs_bmc, false);
652	aspeed_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
653
654	/* Make sure it's proper dead */
655	spin_lock_irq(&priv->obe.lock);
656	priv->obe.remove = true;
657	spin_unlock_irq(&priv->obe.lock);
658	del_timer_sync(&priv->obe.timer);
659
660	return 0;
661}
662
663static const struct of_device_id ast_kcs_bmc_match[] = {
664	{ .compatible = "aspeed,ast2400-kcs-bmc-v2" },
665	{ .compatible = "aspeed,ast2500-kcs-bmc-v2" },
666	{ .compatible = "aspeed,ast2600-kcs-bmc" },
667	{ }
668};
669MODULE_DEVICE_TABLE(of, ast_kcs_bmc_match);
670
671static struct platform_driver ast_kcs_bmc_driver = {
672	.driver = {
673		.name           = DEVICE_NAME,
674		.of_match_table = ast_kcs_bmc_match,
675	},
676	.probe  = aspeed_kcs_probe,
677	.remove = aspeed_kcs_remove,
678};
679module_platform_driver(ast_kcs_bmc_driver);
680
681MODULE_LICENSE("GPL v2");
682MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
683MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
684MODULE_DESCRIPTION("Aspeed device interface to the KCS BMC device");
685