summaryrefslogtreecommitdiff
path: root/drivers/spi/spi-ti-qspi.c
blob: e12d962a289f61823b673098fce9e49dc8da94f7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
/*
 * TI QSPI driver
 *
 * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
 * Author: Sourav Poddar <sourav.poddar@ti.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GPLv2.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR /PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/omap-dma.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pinctrl/consumer.h>

#include <linux/spi/spi.h>

struct ti_qspi_regs {
	u32 clkctrl;
};

struct ti_qspi {
	struct completion       transfer_complete;

	/* IRQ synchronization */
	spinlock_t              lock;

	/* list synchronization */
	struct mutex            list_lock;

	struct spi_master	*master;
	void __iomem            *base;
	struct clk		*fclk;
	struct device           *dev;

	struct ti_qspi_regs     ctx_reg;

	u32 spi_max_frequency;
	u32 cmd;
	u32 dc;
	u32 stat;
};

#define QSPI_PID			(0x0)
#define QSPI_SYSCONFIG			(0x10)
#define QSPI_INTR_STATUS_RAW_SET	(0x20)
#define QSPI_INTR_STATUS_ENABLED_CLEAR	(0x24)
#define QSPI_INTR_ENABLE_SET_REG	(0x28)
#define QSPI_INTR_ENABLE_CLEAR_REG	(0x2c)
#define QSPI_SPI_CLOCK_CNTRL_REG	(0x40)
#define QSPI_SPI_DC_REG			(0x44)
#define QSPI_SPI_CMD_REG		(0x48)
#define QSPI_SPI_STATUS_REG		(0x4c)
#define QSPI_SPI_DATA_REG		(0x50)
#define QSPI_SPI_SETUP0_REG		(0x54)
#define QSPI_SPI_SWITCH_REG		(0x64)
#define QSPI_SPI_SETUP1_REG		(0x58)
#define QSPI_SPI_SETUP2_REG		(0x5c)
#define QSPI_SPI_SETUP3_REG		(0x60)
#define QSPI_SPI_DATA_REG_1		(0x68)
#define QSPI_SPI_DATA_REG_2		(0x6c)
#define QSPI_SPI_DATA_REG_3		(0x70)

#define QSPI_COMPLETION_TIMEOUT		msecs_to_jiffies(2000)

#define QSPI_FCLK			192000000

/* Clock Control */
#define QSPI_CLK_EN			(1 << 31)
#define QSPI_CLK_DIV_MAX		0xffff

/* Command */
#define QSPI_EN_CS(n)			(n << 28)
#define QSPI_WLEN(n)			((n - 1) << 19)
#define QSPI_3_PIN			(1 << 18)
#define QSPI_RD_SNGL			(1 << 16)
#define QSPI_WR_SNGL			(2 << 16)
#define QSPI_RD_DUAL			(3 << 16)
#define QSPI_RD_QUAD			(7 << 16)
#define QSPI_INVAL			(4 << 16)
#define QSPI_WC_CMD_INT_EN			(1 << 14)
#define QSPI_FLEN(n)			((n - 1) << 0)

/* STATUS REGISTER */
#define WC				0x02

/* INTERRUPT REGISTER */
#define QSPI_WC_INT_EN				(1 << 1)
#define QSPI_WC_INT_DISABLE			(1 << 1)

/* Device Control */
#define QSPI_DD(m, n)			(m << (3 + n * 8))
#define QSPI_CKPHA(n)			(1 << (2 + n * 8))
#define QSPI_CSPOL(n)			(1 << (1 + n * 8))
#define QSPI_CKPOL(n)			(1 << (n * 8))

#define	QSPI_FRAME			4096

#define QSPI_AUTOSUSPEND_TIMEOUT         2000

static inline unsigned long ti_qspi_read(struct ti_qspi *qspi,
		unsigned long reg)
{
	return readl(qspi->base + reg);
}

static inline void ti_qspi_write(struct ti_qspi *qspi,
		unsigned long val, unsigned long reg)
{
	writel(val, qspi->base + reg);
}

static int ti_qspi_setup(struct spi_device *spi)
{
	struct ti_qspi	*qspi = spi_master_get_devdata(spi->master);
	struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;
	int clk_div = 0, ret;
	u32 clk_ctrl_reg, clk_rate, clk_mask;

	if (spi->master->busy) {
		dev_dbg(qspi->dev, "master busy doing other trasnfers\n");
		return -EBUSY;
	}

	if (!qspi->spi_max_frequency) {
		dev_err(qspi->dev, "spi max frequency not defined\n");
		return -EINVAL;
	}

	clk_rate = clk_get_rate(qspi->fclk);

	clk_div = DIV_ROUND_UP(clk_rate, qspi->spi_max_frequency) - 1;

	if (clk_div < 0) {
		dev_dbg(qspi->dev, "clock divider < 0, using /1 divider\n");
		return -EINVAL;
	}

	if (clk_div > QSPI_CLK_DIV_MAX) {
		dev_dbg(qspi->dev, "clock divider >%d , using /%d divider\n",
				QSPI_CLK_DIV_MAX, QSPI_CLK_DIV_MAX + 1);
		return -EINVAL;
	}

	dev_dbg(qspi->dev, "hz: %d, clock divider %d\n",
			qspi->spi_max_frequency, clk_div);

	ret = pm_runtime_get_sync(qspi->dev);
	if (ret) {
		dev_err(qspi->dev, "pm_runtime_get_sync() failed\n");
		return ret;
	}

	clk_ctrl_reg = ti_qspi_read(qspi, QSPI_SPI_CLOCK_CNTRL_REG);

	clk_ctrl_reg &= ~QSPI_CLK_EN;

	/* disable SCLK */
	ti_qspi_write(qspi, clk_ctrl_reg, QSPI_SPI_CLOCK_CNTRL_REG);

	/* enable SCLK */
	clk_mask = QSPI_CLK_EN | clk_div;
	ti_qspi_write(qspi, clk_mask, QSPI_SPI_CLOCK_CNTRL_REG);
	ctx_reg->clkctrl = clk_mask;

	pm_runtime_mark_last_busy(qspi->dev);
	ret = pm_runtime_put_autosuspend(qspi->dev);
	if (ret < 0) {
		dev_err(qspi->dev, "pm_runtime_put_autosuspend() failed\n");
		return ret;
	}

	return 0;
}

static void ti_qspi_restore_ctx(struct ti_qspi *qspi)
{
	struct ti_qspi_regs *ctx_reg = &qspi->ctx_reg;

	ti_qspi_write(qspi, ctx_reg->clkctrl, QSPI_SPI_CLOCK_CNTRL_REG);
}

static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t)
{
	int wlen, count, ret;
	unsigned int cmd;
	const u8 *txbuf;

	txbuf = t->tx_buf;
	cmd = qspi->cmd | QSPI_WR_SNGL;
	count = t->len;
	wlen = t->bits_per_word;

	while (count) {
		switch (wlen) {
		case 8:
			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n",
					cmd, qspi->dc, *txbuf);
			writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG);
			ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
			ret = wait_for_completion_timeout(&qspi->transfer_complete,
					QSPI_COMPLETION_TIMEOUT);
			if (ret == 0) {
				dev_err(qspi->dev, "write timed out\n");
				return -ETIMEDOUT;
			}
			txbuf += 1;
			count -= 1;
			break;
		case 16:
			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %04x\n",
					cmd, qspi->dc, *txbuf);
			writew(*((u16 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
			ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
			ret = wait_for_completion_timeout(&qspi->transfer_complete,
				QSPI_COMPLETION_TIMEOUT);
			if (ret == 0) {
				dev_err(qspi->dev, "write timed out\n");
				return -ETIMEDOUT;
			}
			txbuf += 2;
			count -= 2;
			break;
		case 32:
			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %08x\n",
					cmd, qspi->dc, *txbuf);
			writel(*((u32 *)txbuf), qspi->base + QSPI_SPI_DATA_REG);
			ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
			ret = wait_for_completion_timeout(&qspi->transfer_complete,
				QSPI_COMPLETION_TIMEOUT);
			if (ret == 0) {
				dev_err(qspi->dev, "write timed out\n");
				return -ETIMEDOUT;
			}
			txbuf += 4;
			count -= 4;
			break;
		}
	}

	return 0;
}

static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t)
{
	int wlen, count, ret;
	unsigned int cmd;
	u8 *rxbuf;

	rxbuf = t->rx_buf;
	cmd = qspi->cmd;
	switch (t->rx_nbits) {
	case SPI_NBITS_DUAL:
		cmd |= QSPI_RD_DUAL;
		break;
	case SPI_NBITS_QUAD:
		cmd |= QSPI_RD_QUAD;
		break;
	default:
		cmd |= QSPI_RD_SNGL;
		break;
	}
	count = t->len;
	wlen = t->bits_per_word;

	while (count) {
		dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", cmd, qspi->dc);
		ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
		ret = wait_for_completion_timeout(&qspi->transfer_complete,
				QSPI_COMPLETION_TIMEOUT);
		if (ret == 0) {
			dev_err(qspi->dev, "read timed out\n");
			return -ETIMEDOUT;
		}
		switch (wlen) {
		case 8:
			*rxbuf = readb(qspi->base + QSPI_SPI_DATA_REG);
			rxbuf += 1;
			count -= 1;
			break;
		case 16:
			*((u16 *)rxbuf) = readw(qspi->base + QSPI_SPI_DATA_REG);
			rxbuf += 2;
			count -= 2;
			break;
		case 32:
			*((u32 *)rxbuf) = readl(qspi->base + QSPI_SPI_DATA_REG);
			rxbuf += 4;
			count -= 4;
			break;
		}
	}

	return 0;
}

static int qspi_transfer_msg(struct ti_qspi *qspi, struct spi_transfer *t)
{
	int ret;

	if (t->tx_buf) {
		ret = qspi_write_msg(qspi, t);
		if (ret) {
			dev_dbg(qspi->dev, "Error while writing\n");
			return ret;
		}
	}

	if (t->rx_buf) {
		ret = qspi_read_msg(qspi, t);
		if (ret) {
			dev_dbg(qspi->dev, "Error while reading\n");
			return ret;
		}
	}

	return 0;
}

static int ti_qspi_start_transfer_one(struct spi_master *master,
		struct spi_message *m)
{
	struct ti_qspi *qspi = spi_master_get_devdata(master);
	struct spi_device *spi = m->spi;
	struct spi_transfer *t;
	int status = 0, ret;
	int frame_length;

	/* setup device control reg */
	qspi->dc = 0;

	if (spi->mode & SPI_CPHA)
		qspi->dc |= QSPI_CKPHA(spi->chip_select);
	if (spi->mode & SPI_CPOL)
		qspi->dc |= QSPI_CKPOL(spi->chip_select);
	if (spi->mode & SPI_CS_HIGH)
		qspi->dc |= QSPI_CSPOL(spi->chip_select);

	frame_length = (m->frame_length << 3) / spi->bits_per_word;

	frame_length = clamp(frame_length, 0, QSPI_FRAME);

	/* setup command reg */
	qspi->cmd = 0;
	qspi->cmd |= QSPI_EN_CS(spi->chip_select);
	qspi->cmd |= QSPI_FLEN(frame_length);
	qspi->cmd |= QSPI_WC_CMD_INT_EN;

	ti_qspi_write(qspi, QSPI_WC_INT_EN, QSPI_INTR_ENABLE_SET_REG);
	ti_qspi_write(qspi, qspi->dc, QSPI_SPI_DC_REG);

	mutex_lock(&qspi->list_lock);

	list_for_each_entry(t, &m->transfers, transfer_list) {
		qspi->cmd |= QSPI_WLEN(t->bits_per_word);

		ret = qspi_transfer_msg(qspi, t);
		if (ret) {
			dev_dbg(qspi->dev, "transfer message failed\n");
			mutex_unlock(&qspi->list_lock);
			return -EINVAL;
		}

		m->actual_length += t->len;
	}

	mutex_unlock(&qspi->list_lock);

	m->status = status;
	spi_finalize_current_message(master);

	ti_qspi_write(qspi, qspi->cmd | QSPI_INVAL, QSPI_SPI_CMD_REG);

	return status;
}

static irqreturn_t ti_qspi_isr(int irq, void *dev_id)
{
	struct ti_qspi *qspi = dev_id;
	u16 int_stat;

	irqreturn_t ret = IRQ_HANDLED;

	spin_lock(&qspi->lock);

	int_stat = ti_qspi_read(qspi, QSPI_INTR_STATUS_ENABLED_CLEAR);
	qspi->stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);

	if (!int_stat) {
		dev_dbg(qspi->dev, "No IRQ triggered\n");
		ret = IRQ_NONE;
		goto out;
	}

	ret = IRQ_WAKE_THREAD;

	ti_qspi_write(qspi, QSPI_WC_INT_DISABLE, QSPI_INTR_ENABLE_CLEAR_REG);
	ti_qspi_write(qspi, QSPI_WC_INT_DISABLE,
				QSPI_INTR_STATUS_ENABLED_CLEAR);

out:
	spin_unlock(&qspi->lock);

	return ret;
}

static irqreturn_t ti_qspi_threaded_isr(int this_irq, void *dev_id)
{
	struct ti_qspi *qspi = dev_id;
	unsigned long flags;

	spin_lock_irqsave(&qspi->lock, flags);

	if (qspi->stat & WC)
		complete(&qspi->transfer_complete);

	spin_unlock_irqrestore(&qspi->lock, flags);

	ti_qspi_write(qspi, QSPI_WC_INT_EN, QSPI_INTR_ENABLE_SET_REG);

	return IRQ_HANDLED;
}

static int ti_qspi_runtime_resume(struct device *dev)
{
	struct ti_qspi      *qspi;
	struct spi_master       *master;

	master = dev_get_drvdata(dev);
	qspi = spi_master_get_devdata(master);
	ti_qspi_restore_ctx(qspi);

	return 0;
}

static const struct of_device_id ti_qspi_match[] = {
	{.compatible = "ti,dra7xxx-qspi" },
	{.compatible = "ti,am4372-qspi" },
	{},
};
MODULE_DEVICE_TABLE(of, ti_qspi_match);

static int ti_qspi_probe(struct platform_device *pdev)
{
	struct  ti_qspi *qspi;
	struct spi_master *master;
	struct resource         *r;
	struct device_node *np = pdev->dev.of_node;
	u32 max_freq;
	int ret = 0, num_cs, irq;

	master = spi_alloc_master(&pdev->dev, sizeof(*qspi));
	if (!master)
		return -ENOMEM;

	master->mode_bits = SPI_CPOL | SPI_CPHA;

	master->bus_num = -1;
	master->flags = SPI_MASTER_HALF_DUPLEX;
	master->setup = ti_qspi_setup;
	master->auto_runtime_pm = true;
	master->transfer_one_message = ti_qspi_start_transfer_one;
	master->dev.of_node = pdev->dev.of_node;
	master->bits_per_word_mask = BIT(32 - 1) | BIT(16 - 1) | BIT(8 - 1);

	if (!of_property_read_u32(np, "num-cs", &num_cs))
		master->num_chipselect = num_cs;

	platform_set_drvdata(pdev, master);

	qspi = spi_master_get_devdata(master);
	qspi->master = master;
	qspi->dev = &pdev->dev;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		dev_err(&pdev->dev, "no irq resource?\n");
		return irq;
	}

	spin_lock_init(&qspi->lock);
	mutex_init(&qspi->list_lock);

	qspi->base = devm_ioremap_resource(&pdev->dev, r);
	if (IS_ERR(qspi->base)) {
		ret = PTR_ERR(qspi->base);
		goto free_master;
	}

	ret = devm_request_threaded_irq(&pdev->dev, irq, ti_qspi_isr,
			ti_qspi_threaded_isr, 0,
			dev_name(&pdev->dev), qspi);
	if (ret < 0) {
		dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
				irq);
		goto free_master;
	}

	qspi->fclk = devm_clk_get(&pdev->dev, "fck");
	if (IS_ERR(qspi->fclk)) {
		ret = PTR_ERR(qspi->fclk);
		dev_err(&pdev->dev, "could not get clk: %d\n", ret);
	}

	init_completion(&qspi->transfer_complete);

	pm_runtime_use_autosuspend(&pdev->dev);
	pm_runtime_set_autosuspend_delay(&pdev->dev, QSPI_AUTOSUSPEND_TIMEOUT);
	pm_runtime_enable(&pdev->dev);

	if (!of_property_read_u32(np, "spi-max-frequency", &max_freq))
		qspi->spi_max_frequency = max_freq;

	ret = spi_register_master(master);
	if (ret)
		goto free_master;

	return 0;

free_master:
	spi_master_put(master);
	return ret;
}

static int ti_qspi_remove(struct platform_device *pdev)
{
	struct	ti_qspi *qspi = platform_get_drvdata(pdev);

	spi_unregister_master(qspi->master);

	return 0;
}

static const struct dev_pm_ops ti_qspi_pm_ops = {
	.runtime_resume = ti_qspi_runtime_resume,
};

static struct platform_driver ti_qspi_driver = {
	.probe	= ti_qspi_probe,
	.remove	= ti_qspi_remove,
	.driver = {
		.name	= "ti,dra7xxx-qspi",
		.owner	= THIS_MODULE,
		.pm =   &ti_qspi_pm_ops,
		.of_match_table = ti_qspi_match,
	}
};

module_platform_driver(ti_qspi_driver);

MODULE_AUTHOR("Sourav Poddar <sourav.poddar@ti.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("TI QSPI controller driver");