1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ASPEED FMC/SPI Memory Controller Driver
4 *
5 * Copyright (c) 2015-2022, IBM Corporation.
6 * Copyright (c) 2020, ASPEED Corporation.
7 */
8
9#include <linux/clk.h>
10#include <linux/module.h>
11#include <linux/of.h>
12#include <linux/of_platform.h>
13#include <linux/platform_device.h>
14#include <linux/spi/spi.h>
15#include <linux/spi/spi-mem.h>
16
17#define DEVICE_NAME "spi-aspeed-smc"
18
19/* Type setting Register */
20#define CONFIG_REG			0x0
21#define   CONFIG_TYPE_SPI		0x2
22
23/* CE Control Register */
24#define CE_CTRL_REG			0x4
25
26/* CEx Control Register */
27#define CE0_CTRL_REG			0x10
28#define   CTRL_IO_MODE_MASK		GENMASK(30, 28)
29#define   CTRL_IO_SINGLE_DATA	        0x0
30#define   CTRL_IO_DUAL_DATA		BIT(29)
31#define   CTRL_IO_QUAD_DATA		BIT(30)
32#define   CTRL_COMMAND_SHIFT		16
33#define   CTRL_IO_ADDRESS_4B		BIT(13)	/* AST2400 SPI only */
34#define   CTRL_IO_DUMMY_SET(dummy)					\
35	(((((dummy) >> 2) & 0x1) << 14) | (((dummy) & 0x3) << 6))
36#define   CTRL_FREQ_SEL_SHIFT		8
37#define   CTRL_FREQ_SEL_MASK		GENMASK(11, CTRL_FREQ_SEL_SHIFT)
38#define   CTRL_CE_STOP_ACTIVE		BIT(2)
39#define   CTRL_IO_MODE_CMD_MASK		GENMASK(1, 0)
40#define   CTRL_IO_MODE_NORMAL		0x0
41#define   CTRL_IO_MODE_READ		0x1
42#define   CTRL_IO_MODE_WRITE		0x2
43#define   CTRL_IO_MODE_USER		0x3
44
45#define   CTRL_IO_CMD_MASK		0xf0ff40c3
46
47/* CEx Address Decoding Range Register */
48#define CE0_SEGMENT_ADDR_REG		0x30
49
50/* CEx Read timing compensation register */
51#define CE0_TIMING_COMPENSATION_REG	0x94
52
53enum aspeed_spi_ctl_reg_value {
54	ASPEED_SPI_BASE,
55	ASPEED_SPI_READ,
56	ASPEED_SPI_WRITE,
57	ASPEED_SPI_MAX,
58};
59
60struct aspeed_spi;
61
62struct aspeed_spi_chip {
63	struct aspeed_spi	*aspi;
64	u32			 cs;
65	void __iomem		*ctl;
66	void __iomem		*ahb_base;
67	u32			 ahb_window_size;
68	u32			 ctl_val[ASPEED_SPI_MAX];
69	u32			 clk_freq;
70};
71
72struct aspeed_spi_data {
73	u32	ctl0;
74	u32	max_cs;
75	bool	hastype;
76	u32	mode_bits;
77	u32	we0;
78	u32	timing;
79	u32	hclk_mask;
80	u32	hdiv_max;
81
82	u32 (*segment_start)(struct aspeed_spi *aspi, u32 reg);
83	u32 (*segment_end)(struct aspeed_spi *aspi, u32 reg);
84	u32 (*segment_reg)(struct aspeed_spi *aspi, u32 start, u32 end);
85	int (*calibrate)(struct aspeed_spi_chip *chip, u32 hdiv,
86			 const u8 *golden_buf, u8 *test_buf);
87};
88
89#define ASPEED_SPI_MAX_NUM_CS	5
90
91struct aspeed_spi {
92	const struct aspeed_spi_data	*data;
93
94	void __iomem		*regs;
95	void __iomem		*ahb_base;
96	u32			 ahb_base_phy;
97	u32			 ahb_window_size;
98	struct device		*dev;
99
100	struct clk		*clk;
101	u32			 clk_freq;
102
103	struct aspeed_spi_chip	 chips[ASPEED_SPI_MAX_NUM_CS];
104};
105
106static u32 aspeed_spi_get_io_mode(const struct spi_mem_op *op)
107{
108	switch (op->data.buswidth) {
109	case 1:
110		return CTRL_IO_SINGLE_DATA;
111	case 2:
112		return CTRL_IO_DUAL_DATA;
113	case 4:
114		return CTRL_IO_QUAD_DATA;
115	default:
116		return CTRL_IO_SINGLE_DATA;
117	}
118}
119
120static void aspeed_spi_set_io_mode(struct aspeed_spi_chip *chip, u32 io_mode)
121{
122	u32 ctl;
123
124	if (io_mode > 0) {
125		ctl = readl(chip->ctl) & ~CTRL_IO_MODE_MASK;
126		ctl |= io_mode;
127		writel(ctl, chip->ctl);
128	}
129}
130
131static void aspeed_spi_start_user(struct aspeed_spi_chip *chip)
132{
133	u32 ctl = chip->ctl_val[ASPEED_SPI_BASE];
134
135	ctl |= CTRL_IO_MODE_USER | CTRL_CE_STOP_ACTIVE;
136	writel(ctl, chip->ctl);
137
138	ctl &= ~CTRL_CE_STOP_ACTIVE;
139	writel(ctl, chip->ctl);
140}
141
142static void aspeed_spi_stop_user(struct aspeed_spi_chip *chip)
143{
144	u32 ctl = chip->ctl_val[ASPEED_SPI_READ] |
145		CTRL_IO_MODE_USER | CTRL_CE_STOP_ACTIVE;
146
147	writel(ctl, chip->ctl);
148
149	/* Restore defaults */
150	writel(chip->ctl_val[ASPEED_SPI_READ], chip->ctl);
151}
152
153static int aspeed_spi_read_from_ahb(void *buf, void __iomem *src, size_t len)
154{
155	size_t offset = 0;
156
157	if (IS_ALIGNED((uintptr_t)src, sizeof(uintptr_t)) &&
158	    IS_ALIGNED((uintptr_t)buf, sizeof(uintptr_t))) {
159		ioread32_rep(src, buf, len >> 2);
160		offset = len & ~0x3;
161		len -= offset;
162	}
163	ioread8_rep(src, (u8 *)buf + offset, len);
164	return 0;
165}
166
167static int aspeed_spi_write_to_ahb(void __iomem *dst, const void *buf, size_t len)
168{
169	size_t offset = 0;
170
171	if (IS_ALIGNED((uintptr_t)dst, sizeof(uintptr_t)) &&
172	    IS_ALIGNED((uintptr_t)buf, sizeof(uintptr_t))) {
173		iowrite32_rep(dst, buf, len >> 2);
174		offset = len & ~0x3;
175		len -= offset;
176	}
177	iowrite8_rep(dst, (const u8 *)buf + offset, len);
178	return 0;
179}
180
181static int aspeed_spi_send_cmd_addr(struct aspeed_spi_chip *chip, u8 addr_nbytes,
182				    u64 offset, u32 opcode)
183{
184	__be32 temp;
185	u32 cmdaddr;
186
187	switch (addr_nbytes) {
188	case 3:
189		cmdaddr = offset & 0xFFFFFF;
190		cmdaddr |= opcode << 24;
191
192		temp = cpu_to_be32(cmdaddr);
193		aspeed_spi_write_to_ahb(chip->ahb_base, &temp, 4);
194		break;
195	case 4:
196		temp = cpu_to_be32(offset);
197		aspeed_spi_write_to_ahb(chip->ahb_base, &opcode, 1);
198		aspeed_spi_write_to_ahb(chip->ahb_base, &temp, 4);
199		break;
200	default:
201		WARN_ONCE(1, "Unexpected address width %u", addr_nbytes);
202		return -EOPNOTSUPP;
203	}
204	return 0;
205}
206
207static int aspeed_spi_read_reg(struct aspeed_spi_chip *chip,
208			       const struct spi_mem_op *op)
209{
210	aspeed_spi_start_user(chip);
211	aspeed_spi_write_to_ahb(chip->ahb_base, &op->cmd.opcode, 1);
212	aspeed_spi_read_from_ahb(op->data.buf.in,
213				 chip->ahb_base, op->data.nbytes);
214	aspeed_spi_stop_user(chip);
215	return 0;
216}
217
218static int aspeed_spi_write_reg(struct aspeed_spi_chip *chip,
219				const struct spi_mem_op *op)
220{
221	aspeed_spi_start_user(chip);
222	aspeed_spi_write_to_ahb(chip->ahb_base, &op->cmd.opcode, 1);
223	aspeed_spi_write_to_ahb(chip->ahb_base, op->data.buf.out,
224				op->data.nbytes);
225	aspeed_spi_stop_user(chip);
226	return 0;
227}
228
229static ssize_t aspeed_spi_read_user(struct aspeed_spi_chip *chip,
230				    const struct spi_mem_op *op,
231				    u64 offset, size_t len, void *buf)
232{
233	int io_mode = aspeed_spi_get_io_mode(op);
234	u8 dummy = 0xFF;
235	int i;
236	int ret;
237
238	aspeed_spi_start_user(chip);
239
240	ret = aspeed_spi_send_cmd_addr(chip, op->addr.nbytes, offset, op->cmd.opcode);
241	if (ret < 0)
242		return ret;
243
244	if (op->dummy.buswidth && op->dummy.nbytes) {
245		for (i = 0; i < op->dummy.nbytes / op->dummy.buswidth; i++)
246			aspeed_spi_write_to_ahb(chip->ahb_base, &dummy,	sizeof(dummy));
247	}
248
249	aspeed_spi_set_io_mode(chip, io_mode);
250
251	aspeed_spi_read_from_ahb(buf, chip->ahb_base, len);
252	aspeed_spi_stop_user(chip);
253	return 0;
254}
255
256static ssize_t aspeed_spi_write_user(struct aspeed_spi_chip *chip,
257				     const struct spi_mem_op *op)
258{
259	int ret;
260
261	aspeed_spi_start_user(chip);
262	ret = aspeed_spi_send_cmd_addr(chip, op->addr.nbytes, op->addr.val, op->cmd.opcode);
263	if (ret < 0)
264		return ret;
265	aspeed_spi_write_to_ahb(chip->ahb_base, op->data.buf.out, op->data.nbytes);
266	aspeed_spi_stop_user(chip);
267	return 0;
268}
269
270/* support for 1-1-1, 1-1-2 or 1-1-4 */
271static bool aspeed_spi_supports_op(struct spi_mem *mem, const struct spi_mem_op *op)
272{
273	if (op->cmd.buswidth > 1)
274		return false;
275
276	if (op->addr.nbytes != 0) {
277		if (op->addr.buswidth > 1)
278			return false;
279		if (op->addr.nbytes < 3 || op->addr.nbytes > 4)
280			return false;
281	}
282
283	if (op->dummy.nbytes != 0) {
284		if (op->dummy.buswidth > 1 || op->dummy.nbytes > 7)
285			return false;
286	}
287
288	if (op->data.nbytes != 0 && op->data.buswidth > 4)
289		return false;
290
291	return spi_mem_default_supports_op(mem, op);
292}
293
294static const struct aspeed_spi_data ast2400_spi_data;
295
296static int do_aspeed_spi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
297{
298	struct aspeed_spi *aspi = spi_controller_get_devdata(mem->spi->controller);
299	struct aspeed_spi_chip *chip = &aspi->chips[spi_get_chipselect(mem->spi, 0)];
300	u32 addr_mode, addr_mode_backup;
301	u32 ctl_val;
302	int ret = 0;
303
304	dev_dbg(aspi->dev,
305		"CE%d %s OP %#x mode:%d.%d.%d.%d naddr:%#x ndummies:%#x len:%#x",
306		chip->cs, op->data.dir == SPI_MEM_DATA_IN ? "read" : "write",
307		op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
308		op->dummy.buswidth, op->data.buswidth,
309		op->addr.nbytes, op->dummy.nbytes, op->data.nbytes);
310
311	addr_mode = readl(aspi->regs + CE_CTRL_REG);
312	addr_mode_backup = addr_mode;
313
314	ctl_val = chip->ctl_val[ASPEED_SPI_BASE];
315	ctl_val &= ~CTRL_IO_CMD_MASK;
316
317	ctl_val |= op->cmd.opcode << CTRL_COMMAND_SHIFT;
318
319	/* 4BYTE address mode */
320	if (op->addr.nbytes) {
321		if (op->addr.nbytes == 4)
322			addr_mode |= (0x11 << chip->cs);
323		else
324			addr_mode &= ~(0x11 << chip->cs);
325
326		if (op->addr.nbytes == 4 && chip->aspi->data == &ast2400_spi_data)
327			ctl_val |= CTRL_IO_ADDRESS_4B;
328	}
329
330	if (op->dummy.nbytes)
331		ctl_val |= CTRL_IO_DUMMY_SET(op->dummy.nbytes / op->dummy.buswidth);
332
333	if (op->data.nbytes)
334		ctl_val |= aspeed_spi_get_io_mode(op);
335
336	if (op->data.dir == SPI_MEM_DATA_OUT)
337		ctl_val |= CTRL_IO_MODE_WRITE;
338	else
339		ctl_val |= CTRL_IO_MODE_READ;
340
341	if (addr_mode != addr_mode_backup)
342		writel(addr_mode, aspi->regs + CE_CTRL_REG);
343	writel(ctl_val, chip->ctl);
344
345	if (op->data.dir == SPI_MEM_DATA_IN) {
346		if (!op->addr.nbytes)
347			ret = aspeed_spi_read_reg(chip, op);
348		else
349			ret = aspeed_spi_read_user(chip, op, op->addr.val,
350						   op->data.nbytes, op->data.buf.in);
351	} else {
352		if (!op->addr.nbytes)
353			ret = aspeed_spi_write_reg(chip, op);
354		else
355			ret = aspeed_spi_write_user(chip, op);
356	}
357
358	/* Restore defaults */
359	if (addr_mode != addr_mode_backup)
360		writel(addr_mode_backup, aspi->regs + CE_CTRL_REG);
361	writel(chip->ctl_val[ASPEED_SPI_READ], chip->ctl);
362	return ret;
363}
364
365static int aspeed_spi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
366{
367	int ret;
368
369	ret = do_aspeed_spi_exec_op(mem, op);
370	if (ret)
371		dev_err(&mem->spi->dev, "operation failed: %d\n", ret);
372	return ret;
373}
374
375static const char *aspeed_spi_get_name(struct spi_mem *mem)
376{
377	struct aspeed_spi *aspi = spi_controller_get_devdata(mem->spi->controller);
378	struct device *dev = aspi->dev;
379
380	return devm_kasprintf(dev, GFP_KERNEL, "%s.%d", dev_name(dev),
381			      spi_get_chipselect(mem->spi, 0));
382}
383
384struct aspeed_spi_window {
385	u32 cs;
386	u32 offset;
387	u32 size;
388};
389
390static void aspeed_spi_get_windows(struct aspeed_spi *aspi,
391				   struct aspeed_spi_window windows[ASPEED_SPI_MAX_NUM_CS])
392{
393	const struct aspeed_spi_data *data = aspi->data;
394	u32 reg_val;
395	u32 cs;
396
397	for (cs = 0; cs < aspi->data->max_cs; cs++) {
398		reg_val = readl(aspi->regs + CE0_SEGMENT_ADDR_REG + cs * 4);
399		windows[cs].cs = cs;
400		windows[cs].size = data->segment_end(aspi, reg_val) -
401			data->segment_start(aspi, reg_val);
402		windows[cs].offset = data->segment_start(aspi, reg_val) - aspi->ahb_base_phy;
403		dev_vdbg(aspi->dev, "CE%d offset=0x%.8x size=0x%x\n", cs,
404			 windows[cs].offset, windows[cs].size);
405	}
406}
407
408/*
409 * On the AST2600, some CE windows are closed by default at reset but
410 * U-Boot should open all.
411 */
412static int aspeed_spi_chip_set_default_window(struct aspeed_spi_chip *chip)
413{
414	struct aspeed_spi *aspi = chip->aspi;
415	struct aspeed_spi_window windows[ASPEED_SPI_MAX_NUM_CS] = { 0 };
416	struct aspeed_spi_window *win = &windows[chip->cs];
417
418	/* No segment registers for the AST2400 SPI controller */
419	if (aspi->data == &ast2400_spi_data) {
420		win->offset = 0;
421		win->size = aspi->ahb_window_size;
422	} else {
423		aspeed_spi_get_windows(aspi, windows);
424	}
425
426	chip->ahb_base = aspi->ahb_base + win->offset;
427	chip->ahb_window_size = win->size;
428
429	dev_dbg(aspi->dev, "CE%d default window [ 0x%.8x - 0x%.8x ] %dMB",
430		chip->cs, aspi->ahb_base_phy + win->offset,
431		aspi->ahb_base_phy + win->offset + win->size - 1,
432		win->size >> 20);
433
434	return chip->ahb_window_size ? 0 : -1;
435}
436
437static int aspeed_spi_set_window(struct aspeed_spi *aspi,
438				 const struct aspeed_spi_window *win)
439{
440	u32 start = aspi->ahb_base_phy + win->offset;
441	u32 end = start + win->size;
442	void __iomem *seg_reg = aspi->regs + CE0_SEGMENT_ADDR_REG + win->cs * 4;
443	u32 seg_val_backup = readl(seg_reg);
444	u32 seg_val = aspi->data->segment_reg(aspi, start, end);
445
446	if (seg_val == seg_val_backup)
447		return 0;
448
449	writel(seg_val, seg_reg);
450
451	/*
452	 * Restore initial value if something goes wrong else we could
453	 * loose access to the chip.
454	 */
455	if (seg_val != readl(seg_reg)) {
456		dev_err(aspi->dev, "CE%d invalid window [ 0x%.8x - 0x%.8x ] %dMB",
457			win->cs, start, end - 1, win->size >> 20);
458		writel(seg_val_backup, seg_reg);
459		return -EIO;
460	}
461
462	if (win->size)
463		dev_dbg(aspi->dev, "CE%d new window [ 0x%.8x - 0x%.8x ] %dMB",
464			win->cs, start, end - 1,  win->size >> 20);
465	else
466		dev_dbg(aspi->dev, "CE%d window closed", win->cs);
467
468	return 0;
469}
470
471/*
472 * Yet to be done when possible :
473 * - Align mappings on flash size (we don't have the info)
474 * - ioremap each window, not strictly necessary since the overall window
475 *   is correct.
476 */
477static const struct aspeed_spi_data ast2500_spi_data;
478static const struct aspeed_spi_data ast2600_spi_data;
479static const struct aspeed_spi_data ast2600_fmc_data;
480
481static int aspeed_spi_chip_adjust_window(struct aspeed_spi_chip *chip,
482					 u32 local_offset, u32 size)
483{
484	struct aspeed_spi *aspi = chip->aspi;
485	struct aspeed_spi_window windows[ASPEED_SPI_MAX_NUM_CS] = { 0 };
486	struct aspeed_spi_window *win = &windows[chip->cs];
487	int ret;
488
489	/* No segment registers for the AST2400 SPI controller */
490	if (aspi->data == &ast2400_spi_data)
491		return 0;
492
493	/*
494	 * Due to an HW issue on the AST2500 SPI controller, the CE0
495	 * window size should be smaller than the maximum 128MB.
496	 */
497	if (aspi->data == &ast2500_spi_data && chip->cs == 0 && size == SZ_128M) {
498		size = 120 << 20;
499		dev_info(aspi->dev, "CE%d window resized to %dMB (AST2500 HW quirk)",
500			 chip->cs, size >> 20);
501	}
502
503	/*
504	 * The decoding size of AST2600 SPI controller should set at
505	 * least 2MB.
506	 */
507	if ((aspi->data == &ast2600_spi_data || aspi->data == &ast2600_fmc_data) &&
508	    size < SZ_2M) {
509		size = SZ_2M;
510		dev_info(aspi->dev, "CE%d window resized to %dMB (AST2600 Decoding)",
511			 chip->cs, size >> 20);
512	}
513
514	aspeed_spi_get_windows(aspi, windows);
515
516	/* Adjust this chip window */
517	win->offset += local_offset;
518	win->size = size;
519
520	if (win->offset + win->size > aspi->ahb_window_size) {
521		win->size = aspi->ahb_window_size - win->offset;
522		dev_warn(aspi->dev, "CE%d window resized to %dMB", chip->cs, win->size >> 20);
523	}
524
525	ret = aspeed_spi_set_window(aspi, win);
526	if (ret)
527		return ret;
528
529	/* Update chip mapping info */
530	chip->ahb_base = aspi->ahb_base + win->offset;
531	chip->ahb_window_size = win->size;
532
533	/*
534	 * Also adjust next chip window to make sure that it does not
535	 * overlap with the current window.
536	 */
537	if (chip->cs < aspi->data->max_cs - 1) {
538		struct aspeed_spi_window *next = &windows[chip->cs + 1];
539
540		/* Change offset and size to keep the same end address */
541		if ((next->offset + next->size) > (win->offset + win->size))
542			next->size = (next->offset + next->size) - (win->offset + win->size);
543		else
544			next->size = 0;
545		next->offset = win->offset + win->size;
546
547		aspeed_spi_set_window(aspi, next);
548	}
549	return 0;
550}
551
552static int aspeed_spi_do_calibration(struct aspeed_spi_chip *chip);
553
554static int aspeed_spi_dirmap_create(struct spi_mem_dirmap_desc *desc)
555{
556	struct aspeed_spi *aspi = spi_controller_get_devdata(desc->mem->spi->controller);
557	struct aspeed_spi_chip *chip = &aspi->chips[spi_get_chipselect(desc->mem->spi, 0)];
558	struct spi_mem_op *op = &desc->info.op_tmpl;
559	u32 ctl_val;
560	int ret = 0;
561
562	dev_dbg(aspi->dev,
563		"CE%d %s dirmap [ 0x%.8llx - 0x%.8llx ] OP %#x mode:%d.%d.%d.%d naddr:%#x ndummies:%#x\n",
564		chip->cs, op->data.dir == SPI_MEM_DATA_IN ? "read" : "write",
565		desc->info.offset, desc->info.offset + desc->info.length,
566		op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
567		op->dummy.buswidth, op->data.buswidth,
568		op->addr.nbytes, op->dummy.nbytes);
569
570	chip->clk_freq = desc->mem->spi->max_speed_hz;
571
572	/* Only for reads */
573	if (op->data.dir != SPI_MEM_DATA_IN)
574		return -EOPNOTSUPP;
575
576	aspeed_spi_chip_adjust_window(chip, desc->info.offset, desc->info.length);
577
578	if (desc->info.length > chip->ahb_window_size)
579		dev_warn(aspi->dev, "CE%d window (%dMB) too small for mapping",
580			 chip->cs, chip->ahb_window_size >> 20);
581
582	/* Define the default IO read settings */
583	ctl_val = readl(chip->ctl) & ~CTRL_IO_CMD_MASK;
584	ctl_val |= aspeed_spi_get_io_mode(op) |
585		op->cmd.opcode << CTRL_COMMAND_SHIFT |
586		CTRL_IO_MODE_READ;
587
588	if (op->dummy.nbytes)
589		ctl_val |= CTRL_IO_DUMMY_SET(op->dummy.nbytes / op->dummy.buswidth);
590
591	/* Tune 4BYTE address mode */
592	if (op->addr.nbytes) {
593		u32 addr_mode = readl(aspi->regs + CE_CTRL_REG);
594
595		if (op->addr.nbytes == 4)
596			addr_mode |= (0x11 << chip->cs);
597		else
598			addr_mode &= ~(0x11 << chip->cs);
599		writel(addr_mode, aspi->regs + CE_CTRL_REG);
600
601		/* AST2400 SPI controller sets 4BYTE address mode in
602		 * CE0 Control Register
603		 */
604		if (op->addr.nbytes == 4 && chip->aspi->data == &ast2400_spi_data)
605			ctl_val |= CTRL_IO_ADDRESS_4B;
606	}
607
608	/* READ mode is the controller default setting */
609	chip->ctl_val[ASPEED_SPI_READ] = ctl_val;
610	writel(chip->ctl_val[ASPEED_SPI_READ], chip->ctl);
611
612	ret = aspeed_spi_do_calibration(chip);
613
614	dev_info(aspi->dev, "CE%d read buswidth:%d [0x%08x]\n",
615		 chip->cs, op->data.buswidth, chip->ctl_val[ASPEED_SPI_READ]);
616
617	return ret;
618}
619
620static ssize_t aspeed_spi_dirmap_read(struct spi_mem_dirmap_desc *desc,
621				      u64 offset, size_t len, void *buf)
622{
623	struct aspeed_spi *aspi = spi_controller_get_devdata(desc->mem->spi->controller);
624	struct aspeed_spi_chip *chip = &aspi->chips[spi_get_chipselect(desc->mem->spi, 0)];
625
626	/* Switch to USER command mode if mapping window is too small */
627	if (chip->ahb_window_size < offset + len) {
628		int ret;
629
630		ret = aspeed_spi_read_user(chip, &desc->info.op_tmpl, offset, len, buf);
631		if (ret < 0)
632			return ret;
633	} else {
634		memcpy_fromio(buf, chip->ahb_base + offset, len);
635	}
636
637	return len;
638}
639
640static const struct spi_controller_mem_ops aspeed_spi_mem_ops = {
641	.supports_op = aspeed_spi_supports_op,
642	.exec_op = aspeed_spi_exec_op,
643	.get_name = aspeed_spi_get_name,
644	.dirmap_create = aspeed_spi_dirmap_create,
645	.dirmap_read = aspeed_spi_dirmap_read,
646};
647
648static void aspeed_spi_chip_set_type(struct aspeed_spi *aspi, unsigned int cs, int type)
649{
650	u32 reg;
651
652	reg = readl(aspi->regs + CONFIG_REG);
653	reg &= ~(0x3 << (cs * 2));
654	reg |= type << (cs * 2);
655	writel(reg, aspi->regs + CONFIG_REG);
656}
657
658static void aspeed_spi_chip_enable(struct aspeed_spi *aspi, unsigned int cs, bool enable)
659{
660	u32 we_bit = BIT(aspi->data->we0 + cs);
661	u32 reg = readl(aspi->regs + CONFIG_REG);
662
663	if (enable)
664		reg |= we_bit;
665	else
666		reg &= ~we_bit;
667	writel(reg, aspi->regs + CONFIG_REG);
668}
669
670static int aspeed_spi_setup(struct spi_device *spi)
671{
672	struct aspeed_spi *aspi = spi_controller_get_devdata(spi->controller);
673	const struct aspeed_spi_data *data = aspi->data;
674	unsigned int cs = spi_get_chipselect(spi, 0);
675	struct aspeed_spi_chip *chip = &aspi->chips[cs];
676
677	chip->aspi = aspi;
678	chip->cs = cs;
679	chip->ctl = aspi->regs + data->ctl0 + cs * 4;
680
681	/* The driver only supports SPI type flash */
682	if (data->hastype)
683		aspeed_spi_chip_set_type(aspi, cs, CONFIG_TYPE_SPI);
684
685	if (aspeed_spi_chip_set_default_window(chip) < 0) {
686		dev_warn(aspi->dev, "CE%d window invalid", cs);
687		return -EINVAL;
688	}
689
690	aspeed_spi_chip_enable(aspi, cs, true);
691
692	chip->ctl_val[ASPEED_SPI_BASE] = CTRL_CE_STOP_ACTIVE | CTRL_IO_MODE_USER;
693
694	dev_dbg(aspi->dev, "CE%d setup done\n", cs);
695	return 0;
696}
697
698static void aspeed_spi_cleanup(struct spi_device *spi)
699{
700	struct aspeed_spi *aspi = spi_controller_get_devdata(spi->controller);
701	unsigned int cs = spi_get_chipselect(spi, 0);
702
703	aspeed_spi_chip_enable(aspi, cs, false);
704
705	dev_dbg(aspi->dev, "CE%d cleanup done\n", cs);
706}
707
708static void aspeed_spi_enable(struct aspeed_spi *aspi, bool enable)
709{
710	int cs;
711
712	for (cs = 0; cs < aspi->data->max_cs; cs++)
713		aspeed_spi_chip_enable(aspi, cs, enable);
714}
715
716static int aspeed_spi_probe(struct platform_device *pdev)
717{
718	struct device *dev = &pdev->dev;
719	const struct aspeed_spi_data *data;
720	struct spi_controller *ctlr;
721	struct aspeed_spi *aspi;
722	struct resource *res;
723	int ret;
724
725	data = of_device_get_match_data(&pdev->dev);
726	if (!data)
727		return -ENODEV;
728
729	ctlr = devm_spi_alloc_host(dev, sizeof(*aspi));
730	if (!ctlr)
731		return -ENOMEM;
732
733	aspi = spi_controller_get_devdata(ctlr);
734	platform_set_drvdata(pdev, aspi);
735	aspi->data = data;
736	aspi->dev = dev;
737
738	aspi->regs = devm_platform_ioremap_resource(pdev, 0);
739	if (IS_ERR(aspi->regs))
740		return PTR_ERR(aspi->regs);
741
742	aspi->ahb_base = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
743	if (IS_ERR(aspi->ahb_base)) {
744		dev_err(dev, "missing AHB mapping window\n");
745		return PTR_ERR(aspi->ahb_base);
746	}
747
748	aspi->ahb_window_size = resource_size(res);
749	aspi->ahb_base_phy = res->start;
750
751	aspi->clk = devm_clk_get_enabled(&pdev->dev, NULL);
752	if (IS_ERR(aspi->clk)) {
753		dev_err(dev, "missing clock\n");
754		return PTR_ERR(aspi->clk);
755	}
756
757	aspi->clk_freq = clk_get_rate(aspi->clk);
758	if (!aspi->clk_freq) {
759		dev_err(dev, "invalid clock\n");
760		return -EINVAL;
761	}
762
763	/* IRQ is for DMA, which the driver doesn't support yet */
764
765	ctlr->mode_bits = SPI_RX_DUAL | SPI_TX_DUAL | data->mode_bits;
766	ctlr->bus_num = pdev->id;
767	ctlr->mem_ops = &aspeed_spi_mem_ops;
768	ctlr->setup = aspeed_spi_setup;
769	ctlr->cleanup = aspeed_spi_cleanup;
770	ctlr->num_chipselect = data->max_cs;
771	ctlr->dev.of_node = dev->of_node;
772
773	ret = devm_spi_register_controller(dev, ctlr);
774	if (ret)
775		dev_err(&pdev->dev, "spi_register_controller failed\n");
776
777	return ret;
778}
779
780static void aspeed_spi_remove(struct platform_device *pdev)
781{
782	struct aspeed_spi *aspi = platform_get_drvdata(pdev);
783
784	aspeed_spi_enable(aspi, false);
785}
786
787/*
788 * AHB mappings
789 */
790
791/*
792 * The Segment Registers of the AST2400 and AST2500 use a 8MB unit.
793 * The address range is encoded with absolute addresses in the overall
794 * mapping window.
795 */
796static u32 aspeed_spi_segment_start(struct aspeed_spi *aspi, u32 reg)
797{
798	return ((reg >> 16) & 0xFF) << 23;
799}
800
801static u32 aspeed_spi_segment_end(struct aspeed_spi *aspi, u32 reg)
802{
803	return ((reg >> 24) & 0xFF) << 23;
804}
805
806static u32 aspeed_spi_segment_reg(struct aspeed_spi *aspi, u32 start, u32 end)
807{
808	return (((start >> 23) & 0xFF) << 16) | (((end >> 23) & 0xFF) << 24);
809}
810
811/*
812 * The Segment Registers of the AST2600 use a 1MB unit. The address
813 * range is encoded with offsets in the overall mapping window.
814 */
815
816#define AST2600_SEG_ADDR_MASK 0x0ff00000
817
818static u32 aspeed_spi_segment_ast2600_start(struct aspeed_spi *aspi,
819					    u32 reg)
820{
821	u32 start_offset = (reg << 16) & AST2600_SEG_ADDR_MASK;
822
823	return aspi->ahb_base_phy + start_offset;
824}
825
826static u32 aspeed_spi_segment_ast2600_end(struct aspeed_spi *aspi,
827					  u32 reg)
828{
829	u32 end_offset = reg & AST2600_SEG_ADDR_MASK;
830
831	/* segment is disabled */
832	if (!end_offset)
833		return aspi->ahb_base_phy;
834
835	return aspi->ahb_base_phy + end_offset + 0x100000;
836}
837
838static u32 aspeed_spi_segment_ast2600_reg(struct aspeed_spi *aspi,
839					  u32 start, u32 end)
840{
841	/* disable zero size segments */
842	if (start == end)
843		return 0;
844
845	return ((start & AST2600_SEG_ADDR_MASK) >> 16) |
846		((end - 1) & AST2600_SEG_ADDR_MASK);
847}
848
849/*
850 * Read timing compensation sequences
851 */
852
853#define CALIBRATE_BUF_SIZE SZ_16K
854
855static bool aspeed_spi_check_reads(struct aspeed_spi_chip *chip,
856				   const u8 *golden_buf, u8 *test_buf)
857{
858	int i;
859
860	for (i = 0; i < 10; i++) {
861		memcpy_fromio(test_buf, chip->ahb_base, CALIBRATE_BUF_SIZE);
862		if (memcmp(test_buf, golden_buf, CALIBRATE_BUF_SIZE) != 0) {
863#if defined(VERBOSE_DEBUG)
864			print_hex_dump_bytes(DEVICE_NAME "  fail: ", DUMP_PREFIX_NONE,
865					     test_buf, 0x100);
866#endif
867			return false;
868		}
869	}
870	return true;
871}
872
873#define FREAD_TPASS(i)	(((i) / 2) | (((i) & 1) ? 0 : 8))
874
875/*
876 * The timing register is shared by all devices. Only update for CE0.
877 */
878static int aspeed_spi_calibrate(struct aspeed_spi_chip *chip, u32 hdiv,
879				const u8 *golden_buf, u8 *test_buf)
880{
881	struct aspeed_spi *aspi = chip->aspi;
882	const struct aspeed_spi_data *data = aspi->data;
883	int i;
884	int good_pass = -1, pass_count = 0;
885	u32 shift = (hdiv - 1) << 2;
886	u32 mask = ~(0xfu << shift);
887	u32 fread_timing_val = 0;
888
889	/* Try HCLK delay 0..5, each one with/without delay and look for a
890	 * good pair.
891	 */
892	for (i = 0; i < 12; i++) {
893		bool pass;
894
895		if (chip->cs == 0) {
896			fread_timing_val &= mask;
897			fread_timing_val |= FREAD_TPASS(i) << shift;
898			writel(fread_timing_val, aspi->regs + data->timing);
899		}
900		pass = aspeed_spi_check_reads(chip, golden_buf, test_buf);
901		dev_dbg(aspi->dev,
902			"  * [%08x] %d HCLK delay, %dns DI delay : %s",
903			fread_timing_val, i / 2, (i & 1) ? 0 : 4,
904			pass ? "PASS" : "FAIL");
905		if (pass) {
906			pass_count++;
907			if (pass_count == 3) {
908				good_pass = i - 1;
909				break;
910			}
911		} else {
912			pass_count = 0;
913		}
914	}
915
916	/* No good setting for this frequency */
917	if (good_pass < 0)
918		return -1;
919
920	/* We have at least one pass of margin, let's use first pass */
921	if (chip->cs == 0) {
922		fread_timing_val &= mask;
923		fread_timing_val |= FREAD_TPASS(good_pass) << shift;
924		writel(fread_timing_val, aspi->regs + data->timing);
925	}
926	dev_dbg(aspi->dev, " * -> good is pass %d [0x%08x]",
927		good_pass, fread_timing_val);
928	return 0;
929}
930
931static bool aspeed_spi_check_calib_data(const u8 *test_buf, u32 size)
932{
933	const u32 *tb32 = (const u32 *)test_buf;
934	u32 i, cnt = 0;
935
936	/* We check if we have enough words that are neither all 0
937	 * nor all 1's so the calibration can be considered valid.
938	 *
939	 * I use an arbitrary threshold for now of 64
940	 */
941	size >>= 2;
942	for (i = 0; i < size; i++) {
943		if (tb32[i] != 0 && tb32[i] != 0xffffffff)
944			cnt++;
945	}
946	return cnt >= 64;
947}
948
949static const u32 aspeed_spi_hclk_divs[] = {
950	0xf, /* HCLK */
951	0x7, /* HCLK/2 */
952	0xe, /* HCLK/3 */
953	0x6, /* HCLK/4 */
954	0xd, /* HCLK/5 */
955};
956
957#define ASPEED_SPI_HCLK_DIV(i) \
958	(aspeed_spi_hclk_divs[(i) - 1] << CTRL_FREQ_SEL_SHIFT)
959
960static int aspeed_spi_do_calibration(struct aspeed_spi_chip *chip)
961{
962	struct aspeed_spi *aspi = chip->aspi;
963	const struct aspeed_spi_data *data = aspi->data;
964	u32 ahb_freq = aspi->clk_freq;
965	u32 max_freq = chip->clk_freq;
966	u32 ctl_val;
967	u8 *golden_buf = NULL;
968	u8 *test_buf = NULL;
969	int i, rc, best_div = -1;
970
971	dev_dbg(aspi->dev, "calculate timing compensation - AHB freq: %d MHz",
972		ahb_freq / 1000000);
973
974	/*
975	 * use the related low frequency to get check calibration data
976	 * and get golden data.
977	 */
978	ctl_val = chip->ctl_val[ASPEED_SPI_READ] & data->hclk_mask;
979	writel(ctl_val, chip->ctl);
980
981	test_buf = kzalloc(CALIBRATE_BUF_SIZE * 2, GFP_KERNEL);
982	if (!test_buf)
983		return -ENOMEM;
984
985	golden_buf = test_buf + CALIBRATE_BUF_SIZE;
986
987	memcpy_fromio(golden_buf, chip->ahb_base, CALIBRATE_BUF_SIZE);
988	if (!aspeed_spi_check_calib_data(golden_buf, CALIBRATE_BUF_SIZE)) {
989		dev_info(aspi->dev, "Calibration area too uniform, using low speed");
990		goto no_calib;
991	}
992
993#if defined(VERBOSE_DEBUG)
994	print_hex_dump_bytes(DEVICE_NAME "  good: ", DUMP_PREFIX_NONE,
995			     golden_buf, 0x100);
996#endif
997
998	/* Now we iterate the HCLK dividers until we find our breaking point */
999	for (i = ARRAY_SIZE(aspeed_spi_hclk_divs); i > data->hdiv_max - 1; i--) {
1000		u32 tv, freq;
1001
1002		freq = ahb_freq / i;
1003		if (freq > max_freq)
1004			continue;
1005
1006		/* Set the timing */
1007		tv = chip->ctl_val[ASPEED_SPI_READ] | ASPEED_SPI_HCLK_DIV(i);
1008		writel(tv, chip->ctl);
1009		dev_dbg(aspi->dev, "Trying HCLK/%d [%08x] ...", i, tv);
1010		rc = data->calibrate(chip, i, golden_buf, test_buf);
1011		if (rc == 0)
1012			best_div = i;
1013	}
1014
1015	/* Nothing found ? */
1016	if (best_div < 0) {
1017		dev_warn(aspi->dev, "No good frequency, using dumb slow");
1018	} else {
1019		dev_dbg(aspi->dev, "Found good read timings at HCLK/%d", best_div);
1020
1021		/* Record the freq */
1022		for (i = 0; i < ASPEED_SPI_MAX; i++)
1023			chip->ctl_val[i] = (chip->ctl_val[i] & data->hclk_mask) |
1024				ASPEED_SPI_HCLK_DIV(best_div);
1025	}
1026
1027no_calib:
1028	writel(chip->ctl_val[ASPEED_SPI_READ], chip->ctl);
1029	kfree(test_buf);
1030	return 0;
1031}
1032
1033#define TIMING_DELAY_DI		BIT(3)
1034#define TIMING_DELAY_HCYCLE_MAX	5
1035#define TIMING_REG_AST2600(chip)				\
1036	((chip)->aspi->regs + (chip)->aspi->data->timing +	\
1037	 (chip)->cs * 4)
1038
1039static int aspeed_spi_ast2600_calibrate(struct aspeed_spi_chip *chip, u32 hdiv,
1040					const u8 *golden_buf, u8 *test_buf)
1041{
1042	struct aspeed_spi *aspi = chip->aspi;
1043	int hcycle;
1044	u32 shift = (hdiv - 2) << 3;
1045	u32 mask = ~(0xfu << shift);
1046	u32 fread_timing_val = 0;
1047
1048	for (hcycle = 0; hcycle <= TIMING_DELAY_HCYCLE_MAX; hcycle++) {
1049		int delay_ns;
1050		bool pass = false;
1051
1052		fread_timing_val &= mask;
1053		fread_timing_val |= hcycle << shift;
1054
1055		/* no DI input delay first  */
1056		writel(fread_timing_val, TIMING_REG_AST2600(chip));
1057		pass = aspeed_spi_check_reads(chip, golden_buf, test_buf);
1058		dev_dbg(aspi->dev,
1059			"  * [%08x] %d HCLK delay, DI delay none : %s",
1060			fread_timing_val, hcycle, pass ? "PASS" : "FAIL");
1061		if (pass)
1062			return 0;
1063
1064		/* Add DI input delays  */
1065		fread_timing_val &= mask;
1066		fread_timing_val |= (TIMING_DELAY_DI | hcycle) << shift;
1067
1068		for (delay_ns = 0; delay_ns < 0x10; delay_ns++) {
1069			fread_timing_val &= ~(0xf << (4 + shift));
1070			fread_timing_val |= delay_ns << (4 + shift);
1071
1072			writel(fread_timing_val, TIMING_REG_AST2600(chip));
1073			pass = aspeed_spi_check_reads(chip, golden_buf, test_buf);
1074			dev_dbg(aspi->dev,
1075				"  * [%08x] %d HCLK delay, DI delay %d.%dns : %s",
1076				fread_timing_val, hcycle, (delay_ns + 1) / 2,
1077				(delay_ns + 1) & 1 ? 5 : 5, pass ? "PASS" : "FAIL");
1078			/*
1079			 * TODO: This is optimistic. We should look
1080			 * for a working interval and save the middle
1081			 * value in the read timing register.
1082			 */
1083			if (pass)
1084				return 0;
1085		}
1086	}
1087
1088	/* No good setting for this frequency */
1089	return -1;
1090}
1091
1092/*
1093 * Platform definitions
1094 */
1095static const struct aspeed_spi_data ast2400_fmc_data = {
1096	.max_cs	       = 5,
1097	.hastype       = true,
1098	.we0	       = 16,
1099	.ctl0	       = CE0_CTRL_REG,
1100	.timing	       = CE0_TIMING_COMPENSATION_REG,
1101	.hclk_mask     = 0xfffff0ff,
1102	.hdiv_max      = 1,
1103	.calibrate     = aspeed_spi_calibrate,
1104	.segment_start = aspeed_spi_segment_start,
1105	.segment_end   = aspeed_spi_segment_end,
1106	.segment_reg   = aspeed_spi_segment_reg,
1107};
1108
1109static const struct aspeed_spi_data ast2400_spi_data = {
1110	.max_cs	       = 1,
1111	.hastype       = false,
1112	.we0	       = 0,
1113	.ctl0	       = 0x04,
1114	.timing	       = 0x14,
1115	.hclk_mask     = 0xfffff0ff,
1116	.hdiv_max      = 1,
1117	.calibrate     = aspeed_spi_calibrate,
1118	/* No segment registers */
1119};
1120
1121static const struct aspeed_spi_data ast2500_fmc_data = {
1122	.max_cs	       = 3,
1123	.hastype       = true,
1124	.we0	       = 16,
1125	.ctl0	       = CE0_CTRL_REG,
1126	.timing	       = CE0_TIMING_COMPENSATION_REG,
1127	.hclk_mask     = 0xffffd0ff,
1128	.hdiv_max      = 1,
1129	.calibrate     = aspeed_spi_calibrate,
1130	.segment_start = aspeed_spi_segment_start,
1131	.segment_end   = aspeed_spi_segment_end,
1132	.segment_reg   = aspeed_spi_segment_reg,
1133};
1134
1135static const struct aspeed_spi_data ast2500_spi_data = {
1136	.max_cs	       = 2,
1137	.hastype       = false,
1138	.we0	       = 16,
1139	.ctl0	       = CE0_CTRL_REG,
1140	.timing	       = CE0_TIMING_COMPENSATION_REG,
1141	.hclk_mask     = 0xffffd0ff,
1142	.hdiv_max      = 1,
1143	.calibrate     = aspeed_spi_calibrate,
1144	.segment_start = aspeed_spi_segment_start,
1145	.segment_end   = aspeed_spi_segment_end,
1146	.segment_reg   = aspeed_spi_segment_reg,
1147};
1148
1149static const struct aspeed_spi_data ast2600_fmc_data = {
1150	.max_cs	       = 3,
1151	.hastype       = false,
1152	.mode_bits     = SPI_RX_QUAD | SPI_TX_QUAD,
1153	.we0	       = 16,
1154	.ctl0	       = CE0_CTRL_REG,
1155	.timing	       = CE0_TIMING_COMPENSATION_REG,
1156	.hclk_mask     = 0xf0fff0ff,
1157	.hdiv_max      = 2,
1158	.calibrate     = aspeed_spi_ast2600_calibrate,
1159	.segment_start = aspeed_spi_segment_ast2600_start,
1160	.segment_end   = aspeed_spi_segment_ast2600_end,
1161	.segment_reg   = aspeed_spi_segment_ast2600_reg,
1162};
1163
1164static const struct aspeed_spi_data ast2600_spi_data = {
1165	.max_cs	       = 2,
1166	.hastype       = false,
1167	.mode_bits     = SPI_RX_QUAD | SPI_TX_QUAD,
1168	.we0	       = 16,
1169	.ctl0	       = CE0_CTRL_REG,
1170	.timing	       = CE0_TIMING_COMPENSATION_REG,
1171	.hclk_mask     = 0xf0fff0ff,
1172	.hdiv_max      = 2,
1173	.calibrate     = aspeed_spi_ast2600_calibrate,
1174	.segment_start = aspeed_spi_segment_ast2600_start,
1175	.segment_end   = aspeed_spi_segment_ast2600_end,
1176	.segment_reg   = aspeed_spi_segment_ast2600_reg,
1177};
1178
1179static const struct of_device_id aspeed_spi_matches[] = {
1180	{ .compatible = "aspeed,ast2400-fmc", .data = &ast2400_fmc_data },
1181	{ .compatible = "aspeed,ast2400-spi", .data = &ast2400_spi_data },
1182	{ .compatible = "aspeed,ast2500-fmc", .data = &ast2500_fmc_data },
1183	{ .compatible = "aspeed,ast2500-spi", .data = &ast2500_spi_data },
1184	{ .compatible = "aspeed,ast2600-fmc", .data = &ast2600_fmc_data },
1185	{ .compatible = "aspeed,ast2600-spi", .data = &ast2600_spi_data },
1186	{ }
1187};
1188MODULE_DEVICE_TABLE(of, aspeed_spi_matches);
1189
1190static struct platform_driver aspeed_spi_driver = {
1191	.probe			= aspeed_spi_probe,
1192	.remove_new		= aspeed_spi_remove,
1193	.driver	= {
1194		.name		= DEVICE_NAME,
1195		.of_match_table = aspeed_spi_matches,
1196	}
1197};
1198
1199module_platform_driver(aspeed_spi_driver);
1200
1201MODULE_DESCRIPTION("ASPEED Static Memory Controller Driver");
1202MODULE_AUTHOR("Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>");
1203MODULE_AUTHOR("Cedric Le Goater <clg@kaod.org>");
1204MODULE_LICENSE("GPL v2");
1205