aboutsummaryrefslogtreecommitdiff
path: root/drivers/spi/spi-coldfire-qspi.c
blob: 5ff48ab2f5344ec2b223ea020467faf18c7b94d6 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Freescale/Motorola Coldfire Queued SPI driver
 *
 * Copyright 2010 Steven King <sfking@fdwdc.com>
*/

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/spi/spi.h>
#include <linux/pm_runtime.h>

#include <asm/coldfire.h>
#include <asm/mcfsim.h>
#include <asm/mcfqspi.h>

#define	DRIVER_NAME "mcfqspi"

#define	MCFQSPI_BUSCLK			(MCF_BUSCLK / 2)

#define	MCFQSPI_QMR			0x00
#define		MCFQSPI_QMR_MSTR	0x8000
#define		MCFQSPI_QMR_CPOL	0x0200
#define		MCFQSPI_QMR_CPHA	0x0100
#define	MCFQSPI_QDLYR			0x04
#define		MCFQSPI_QDLYR_SPE	0x8000
#define	MCFQSPI_QWR			0x08
#define		MCFQSPI_QWR_HALT	0x8000
#define		MCFQSPI_QWR_WREN	0x4000
#define		MCFQSPI_QWR_CSIV	0x1000
#define	MCFQSPI_QIR			0x0C
#define		MCFQSPI_QIR_WCEFB	0x8000
#define		MCFQSPI_QIR_ABRTB	0x4000
#define		MCFQSPI_QIR_ABRTL	0x1000
#define		MCFQSPI_QIR_WCEFE	0x0800
#define		MCFQSPI_QIR_ABRTE	0x0400
#define		MCFQSPI_QIR_SPIFE	0x0100
#define		MCFQSPI_QIR_WCEF	0x0008
#define		MCFQSPI_QIR_ABRT	0x0004
#define		MCFQSPI_QIR_SPIF	0x0001
#define	MCFQSPI_QAR			0x010
#define		MCFQSPI_QAR_TXBUF	0x00
#define		MCFQSPI_QAR_RXBUF	0x10
#define		MCFQSPI_QAR_CMDBUF	0x20
#define	MCFQSPI_QDR			0x014
#define	MCFQSPI_QCR			0x014
#define		MCFQSPI_QCR_CONT	0x8000
#define		MCFQSPI_QCR_BITSE	0x4000
#define		MCFQSPI_QCR_DT		0x2000

struct mcfqspi {
	void __iomem *iobase;
	int irq;
	struct clk *clk;
	struct mcfqspi_cs_control *cs_control;

	wait_queue_head_t waitq;
};

static void mcfqspi_wr_qmr(struct mcfqspi *mcfqspi, u16 val)
{
	writew(val, mcfqspi->iobase + MCFQSPI_QMR);
}

static void mcfqspi_wr_qdlyr(struct mcfqspi *mcfqspi, u16 val)
{
	writew(val, mcfqspi->iobase + MCFQSPI_QDLYR);
}

static u16 mcfqspi_rd_qdlyr(struct mcfqspi *mcfqspi)
{
	return readw(mcfqspi->iobase + MCFQSPI_QDLYR);
}

static void mcfqspi_wr_qwr(struct mcfqspi *mcfqspi, u16 val)
{
	writew(val, mcfqspi->iobase + MCFQSPI_QWR);
}

static void mcfqspi_wr_qir(struct mcfqspi *mcfqspi, u16 val)
{
	writew(val, mcfqspi->iobase + MCFQSPI_QIR);
}

static void mcfqspi_wr_qar(struct mcfqspi *mcfqspi, u16 val)
{
	writew(val, mcfqspi->iobase + MCFQSPI_QAR);
}

static void mcfqspi_wr_qdr(struct mcfqspi *mcfqspi, u16 val)
{
	writew(val, mcfqspi->iobase + MCFQSPI_QDR);
}

static u16 mcfqspi_rd_qdr(struct mcfqspi *mcfqspi)
{
	return readw(mcfqspi->iobase + MCFQSPI_QDR);
}

static void mcfqspi_cs_select(struct mcfqspi *mcfqspi, u8 chip_select,
			    bool cs_high)
{
	mcfqspi->cs_control->select(mcfqspi->cs_control, chip_select, cs_high);
}

static void mcfqspi_cs_deselect(struct mcfqspi *mcfqspi, u8 chip_select,
				bool cs_high)
{
	mcfqspi->cs_control->deselect(mcfqspi->cs_control, chip_select, cs_high);
}

static int mcfqspi_cs_setup(struct mcfqspi *mcfqspi)
{
	return (mcfqspi->cs_control->setup) ?
		mcfqspi->cs_control->setup(mcfqspi->cs_control) : 0;
}

static void mcfqspi_cs_teardown(struct mcfqspi *mcfqspi)
{
	if (mcfqspi->cs_control->teardown)
		mcfqspi->cs_control->teardown(mcfqspi->cs_control);
}

static u8 mcfqspi_qmr_baud(u32 speed_hz)
{
	return clamp((MCFQSPI_BUSCLK + speed_hz - 1) / speed_hz, 2u, 255u);
}

static bool mcfqspi_qdlyr_spe(struct mcfqspi *mcfqspi)
{
	return mcfqspi_rd_qdlyr(mcfqspi) & MCFQSPI_QDLYR_SPE;
}

static irqreturn_t mcfqspi_irq_handler(int this_irq, void *dev_id)
{
	struct mcfqspi *mcfqspi = dev_id;

	/* clear interrupt */
	mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE | MCFQSPI_QIR_SPIF);
	wake_up(&mcfqspi->waitq);

	return IRQ_HANDLED;
}

static void mcfqspi_transfer_msg8(struct mcfqspi *mcfqspi, unsigned count,
				  const u8 *txbuf, u8 *rxbuf)
{
	unsigned i, n, offset = 0;

	n = min(count, 16u);

	mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF);
	for (i = 0; i < n; ++i)
		mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE);

	mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF);
	if (txbuf)
		for (i = 0; i < n; ++i)
			mcfqspi_wr_qdr(mcfqspi, *txbuf++);
	else
		for (i = 0; i < count; ++i)
			mcfqspi_wr_qdr(mcfqspi, 0);

	count -= n;
	if (count) {
		u16 qwr = 0xf08;
		mcfqspi_wr_qwr(mcfqspi, 0x700);
		mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);

		do {
			wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
			mcfqspi_wr_qwr(mcfqspi, qwr);
			mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
			if (rxbuf) {
				mcfqspi_wr_qar(mcfqspi,
					       MCFQSPI_QAR_RXBUF + offset);
				for (i = 0; i < 8; ++i)
					*rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
			}
			n = min(count, 8u);
			if (txbuf) {
				mcfqspi_wr_qar(mcfqspi,
					       MCFQSPI_QAR_TXBUF + offset);
				for (i = 0; i < n; ++i)
					mcfqspi_wr_qdr(mcfqspi, *txbuf++);
			}
			qwr = (offset ? 0x808 : 0) + ((n - 1) << 8);
			offset ^= 8;
			count -= n;
		} while (count);
		wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
		mcfqspi_wr_qwr(mcfqspi, qwr);
		mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
		if (rxbuf) {
			mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
			for (i = 0; i < 8; ++i)
				*rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
			offset ^= 8;
		}
	} else {
		mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8);
		mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
	}
	wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
	if (rxbuf) {
		mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
		for (i = 0; i < n; ++i)
			*rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
	}
}

static void mcfqspi_transfer_msg16(struct mcfqspi *mcfqspi, unsigned count,
				   const u16 *txbuf, u16 *rxbuf)
{
	unsigned i, n, offset = 0;

	n = min(count, 16u);

	mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF);
	for (i = 0; i < n; ++i)
		mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE);

	mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF);
	if (txbuf)
		for (i = 0; i < n; ++i)
			mcfqspi_wr_qdr(mcfqspi, *txbuf++);
	else
		for (i = 0; i < count; ++i)
			mcfqspi_wr_qdr(mcfqspi, 0);

	count -= n;
	if (count) {
		u16 qwr = 0xf08;
		mcfqspi_wr_qwr(mcfqspi, 0x700);
		mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);

		do {
			wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
			mcfqspi_wr_qwr(mcfqspi, qwr);
			mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
			if (rxbuf) {
				mcfqspi_wr_qar(mcfqspi,
					       MCFQSPI_QAR_RXBUF + offset);
				for (i = 0; i < 8; ++i)
					*rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
			}
			n = min(count, 8u);
			if (txbuf) {
				mcfqspi_wr_qar(mcfqspi,
					       MCFQSPI_QAR_TXBUF + offset);
				for (i = 0; i < n; ++i)
					mcfqspi_wr_qdr(mcfqspi, *txbuf++);
			}
			qwr = (offset ? 0x808 : 0x000) + ((n - 1) << 8);
			offset ^= 8;
			count -= n;
		} while (count);
		wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
		mcfqspi_wr_qwr(mcfqspi, qwr);
		mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
		if (rxbuf) {
			mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
			for (i = 0; i < 8; ++i)
				*rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
			offset ^= 8;
		}
	} else {
		mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8);
		mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
	}
	wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
	if (rxbuf) {
		mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
		for (i = 0; i < n; ++i)
			*rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
	}
}

static void mcfqspi_set_cs(struct spi_device *spi, bool enable)
{
	struct mcfqspi *mcfqspi = spi_master_get_devdata(spi->master);
	bool cs_high = spi->mode & SPI_CS_HIGH;

	if (enable)
		mcfqspi_cs_select(mcfqspi, spi->chip_select, cs_high);
	else
		mcfqspi_cs_deselect(mcfqspi, spi->chip_select, cs_high);
}

static int mcfqspi_transfer_one(struct spi_master *master,
				struct spi_device *spi,
				struct spi_transfer *t)
{
	struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
	u16 qmr = MCFQSPI_QMR_MSTR;

	qmr |= t->bits_per_word << 10;
	if (spi->mode & SPI_CPHA)
		qmr |= MCFQSPI_QMR_CPHA;
	if (spi->mode & SPI_CPOL)
		qmr |= MCFQSPI_QMR_CPOL;
	qmr |= mcfqspi_qmr_baud(t->speed_hz);
	mcfqspi_wr_qmr(mcfqspi, qmr);

	mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE);
	if (t->bits_per_word == 8)
		mcfqspi_transfer_msg8(mcfqspi, t->len, t->tx_buf, t->rx_buf);
	else
		mcfqspi_transfer_msg16(mcfqspi, t->len / 2, t->tx_buf,
				       t->rx_buf);
	mcfqspi_wr_qir(mcfqspi, 0);

	return 0;
}

static int mcfqspi_setup(struct spi_device *spi)
{
	mcfqspi_cs_deselect(spi_master_get_devdata(spi->master),
			    spi->chip_select, spi->mode & SPI_CS_HIGH);

	dev_dbg(&spi->dev,
			"bits per word %d, chip select %d, speed %d KHz\n",
			spi->bits_per_word, spi->chip_select,
			(MCFQSPI_BUSCLK / mcfqspi_qmr_baud(spi->max_speed_hz))
			/ 1000);

	return 0;
}

static int mcfqspi_probe(struct platform_device *pdev)
{
	struct spi_master *master;
	struct mcfqspi *mcfqspi;
	struct resource *res;
	struct mcfqspi_platform_data *pdata;
	int status;

	pdata = dev_get_platdata(&pdev->dev);
	if (!pdata) {
		dev_dbg(&pdev->dev, "platform data is missing\n");
		return -ENOENT;
	}

	if (!pdata->cs_control) {
		dev_dbg(&pdev->dev, "pdata->cs_control is NULL\n");
		return -EINVAL;
	}

	master = spi_alloc_master(&pdev->dev, sizeof(*mcfqspi));
	if (master == NULL) {
		dev_dbg(&pdev->dev, "spi_alloc_master failed\n");
		return -ENOMEM;
	}

	mcfqspi = spi_master_get_devdata(master);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	mcfqspi->iobase = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(mcfqspi->iobase)) {
		status = PTR_ERR(mcfqspi->iobase);
		goto fail0;
	}

	mcfqspi->irq = platform_get_irq(pdev, 0);
	if (mcfqspi->irq < 0) {
		dev_dbg(&pdev->dev, "platform_get_irq failed\n");
		status = -ENXIO;
		goto fail0;
	}

	status = devm_request_irq(&pdev->dev, mcfqspi->irq, mcfqspi_irq_handler,
				0, pdev->name, mcfqspi);
	if (status) {
		dev_dbg(&pdev->dev, "request_irq failed\n");
		goto fail0;
	}

	mcfqspi->clk = devm_clk_get(&pdev->dev, "qspi_clk");
	if (IS_ERR(mcfqspi->clk)) {
		dev_dbg(&pdev->dev, "clk_get failed\n");
		status = PTR_ERR(mcfqspi->clk);
		goto fail0;
	}
	clk_enable(mcfqspi->clk);

	master->bus_num = pdata->bus_num;
	master->num_chipselect = pdata->num_chipselect;

	mcfqspi->cs_control = pdata->cs_control;
	status = mcfqspi_cs_setup(mcfqspi);
	if (status) {
		dev_dbg(&pdev->dev, "error initializing cs_control\n");
		goto fail1;
	}

	init_waitqueue_head(&mcfqspi->waitq);

	master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16);
	master->setup = mcfqspi_setup;
	master->set_cs = mcfqspi_set_cs;
	master->transfer_one = mcfqspi_transfer_one;
	master->auto_runtime_pm = true;

	platform_set_drvdata(pdev, master);
	pm_runtime_enable(&pdev->dev);

	status = devm_spi_register_master(&pdev->dev, master);
	if (status) {
		dev_dbg(&pdev->dev, "spi_register_master failed\n");
		goto fail2;
	}

	dev_info(&pdev->dev, "Coldfire QSPI bus driver\n");

	return 0;

fail2:
	pm_runtime_disable(&pdev->dev);
	mcfqspi_cs_teardown(mcfqspi);
fail1:
	clk_disable(mcfqspi->clk);
fail0:
	spi_master_put(master);

	dev_dbg(&pdev->dev, "Coldfire QSPI probe failed\n");

	return status;
}

static int mcfqspi_remove(struct platform_device *pdev)
{
	struct spi_master *master = platform_get_drvdata(pdev);
	struct mcfqspi *mcfqspi = spi_master_get_devdata(master);

	pm_runtime_disable(&pdev->dev);
	/* disable the hardware (set the baud rate to 0) */
	mcfqspi_wr_qmr(mcfqspi, MCFQSPI_QMR_MSTR);

	mcfqspi_cs_teardown(mcfqspi);
	clk_disable(mcfqspi->clk);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int mcfqspi_suspend(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
	int ret;

	ret = spi_master_suspend(master);
	if (ret)
		return ret;

	clk_disable(mcfqspi->clk);

	return 0;
}

static int mcfqspi_resume(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	struct mcfqspi *mcfqspi = spi_master_get_devdata(master);

	clk_enable(mcfqspi->clk);

	return spi_master_resume(master);
}
#endif

#ifdef CONFIG_PM
static int mcfqspi_runtime_suspend(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	struct mcfqspi *mcfqspi = spi_master_get_devdata(master);

	clk_disable(mcfqspi->clk);

	return 0;
}

static int mcfqspi_runtime_resume(struct device *dev)
{
	struct spi_master *master = dev_get_drvdata(dev);
	struct mcfqspi *mcfqspi = spi_master_get_devdata(master);

	clk_enable(mcfqspi->clk);

	return 0;
}
#endif

static const struct dev_pm_ops mcfqspi_pm = {
	SET_SYSTEM_SLEEP_PM_OPS(mcfqspi_suspend, mcfqspi_resume)
	SET_RUNTIME_PM_OPS(mcfqspi_runtime_suspend, mcfqspi_runtime_resume,
			NULL)
};

static struct platform_driver mcfqspi_driver = {
	.driver.name	= DRIVER_NAME,
	.driver.owner	= THIS_MODULE,
	.driver.pm	= &mcfqspi_pm,
	.probe		= mcfqspi_probe,
	.remove		= mcfqspi_remove,
};
module_platform_driver(mcfqspi_driver);

MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
MODULE_DESCRIPTION("Coldfire QSPI Controller Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRIVER_NAME);