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1/*
2 * Marvell Orion SPI controller driver
3 *
4 * Author: Shadi Ammouri <shadi@marvell.com>
5 * Copyright (C) 2007-2008 Marvell Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/init.h>
13#include <linux/interrupt.h>
14#include <linux/delay.h>
15#include <linux/platform_device.h>
16#include <linux/err.h>
17#include <linux/io.h>
18#include <linux/spi/spi.h>
19#include <linux/spi/orion_spi.h>
20#include <asm/unaligned.h>
21
22#define DRIVER_NAME "orion_spi"
23
24#define ORION_NUM_CHIPSELECTS 1 /* only one slave is supported*/
25#define ORION_SPI_WAIT_RDY_MAX_LOOP 2000 /* in usec */
26
27#define ORION_SPI_IF_CTRL_REG 0x00
28#define ORION_SPI_IF_CONFIG_REG 0x04
29#define ORION_SPI_DATA_OUT_REG 0x08
30#define ORION_SPI_DATA_IN_REG 0x0c
31#define ORION_SPI_INT_CAUSE_REG 0x10
32
33#define ORION_SPI_IF_8_16_BIT_MODE (1 << 5)
34#define ORION_SPI_CLK_PRESCALE_MASK 0x1F
35
36struct orion_spi {
37 struct work_struct work;
38
39 /* Lock access to transfer list. */
40 spinlock_t lock;
41
42 struct list_head msg_queue;
43 struct spi_master *master;
44 void __iomem *base;
45 unsigned int max_speed;
46 unsigned int min_speed;
47 struct orion_spi_info *spi_info;
48};
49
50static struct workqueue_struct *orion_spi_wq;
51
52static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
53{
54 return orion_spi->base + reg;
55}
56
57static inline void
58orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
59{
60 void __iomem *reg_addr = spi_reg(orion_spi, reg);
61 u32 val;
62
63 val = readl(reg_addr);
64 val |= mask;
65 writel(val, reg_addr);
66}
67
68static inline void
69orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
70{
71 void __iomem *reg_addr = spi_reg(orion_spi, reg);
72 u32 val;
73
74 val = readl(reg_addr);
75 val &= ~mask;
76 writel(val, reg_addr);
77}
78
79static int orion_spi_set_transfer_size(struct orion_spi *orion_spi, int size)
80{
81 if (size == 16) {
82 orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
83 ORION_SPI_IF_8_16_BIT_MODE);
84 } else if (size == 8) {
85 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
86 ORION_SPI_IF_8_16_BIT_MODE);
87 } else {
88 pr_debug("Bad bits per word value %d (only 8 or 16 are "
89 "allowed).\n", size);
90 return -EINVAL;
91 }
92
93 return 0;
94}
95
96static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
97{
98 u32 tclk_hz;
99 u32 rate;
100 u32 prescale;
101 u32 reg;
102 struct orion_spi *orion_spi;
103
104 orion_spi = spi_master_get_devdata(spi->master);
105
106 tclk_hz = orion_spi->spi_info->tclk;
107
108 /*
109 * the supported rates are: 4,6,8...30
110 * round up as we look for equal or less speed
111 */
112 rate = DIV_ROUND_UP(tclk_hz, speed);
113 rate = roundup(rate, 2);
114
115 /* check if requested speed is too small */
116 if (rate > 30)
117 return -EINVAL;
118
119 if (rate < 4)
120 rate = 4;
121
122 /* Convert the rate to SPI clock divisor value. */
123 prescale = 0x10 + rate/2;
124
125 reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
126 reg = ((reg & ~ORION_SPI_CLK_PRESCALE_MASK) | prescale);
127 writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
128
129 return 0;
130}
131
132/*
133 * called only when no transfer is active on the bus
134 */
135static int
136orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
137{
138 struct orion_spi *orion_spi;
139 unsigned int speed = spi->max_speed_hz;
140 unsigned int bits_per_word = spi->bits_per_word;
141 int rc;
142
143 orion_spi = spi_master_get_devdata(spi->master);
144
145 if ((t != NULL) && t->speed_hz)
146 speed = t->speed_hz;
147
148 if ((t != NULL) && t->bits_per_word)
149 bits_per_word = t->bits_per_word;
150
151 rc = orion_spi_baudrate_set(spi, speed);
152 if (rc)
153 return rc;
154
155 return orion_spi_set_transfer_size(orion_spi, bits_per_word);
156}
157
158static void orion_spi_set_cs(struct orion_spi *orion_spi, int enable)
159{
160 if (enable)
161 orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
162 else
163 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
164}
165
166static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
167{
168 int i;
169
170 for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
171 if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
172 return 1;
173 else
174 udelay(1);
175 }
176
177 return -1;
178}
179
180static inline int
181orion_spi_write_read_8bit(struct spi_device *spi,
182 const u8 **tx_buf, u8 **rx_buf)
183{
184 void __iomem *tx_reg, *rx_reg, *int_reg;
185 struct orion_spi *orion_spi;
186
187 orion_spi = spi_master_get_devdata(spi->master);
188 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
189 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
190 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
191
192 /* clear the interrupt cause register */
193 writel(0x0, int_reg);
194
195 if (tx_buf && *tx_buf)
196 writel(*(*tx_buf)++, tx_reg);
197 else
198 writel(0, tx_reg);
199
200 if (orion_spi_wait_till_ready(orion_spi) < 0) {
201 dev_err(&spi->dev, "TXS timed out\n");
202 return -1;
203 }
204
205 if (rx_buf && *rx_buf)
206 *(*rx_buf)++ = readl(rx_reg);
207
208 return 1;
209}
210
211static inline int
212orion_spi_write_read_16bit(struct spi_device *spi,
213 const u16 **tx_buf, u16 **rx_buf)
214{
215 void __iomem *tx_reg, *rx_reg, *int_reg;
216 struct orion_spi *orion_spi;
217
218 orion_spi = spi_master_get_devdata(spi->master);
219 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
220 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
221 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
222
223 /* clear the interrupt cause register */
224 writel(0x0, int_reg);
225
226 if (tx_buf && *tx_buf)
227 writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
228 else
229 writel(0, tx_reg);
230
231 if (orion_spi_wait_till_ready(orion_spi) < 0) {
232 dev_err(&spi->dev, "TXS timed out\n");
233 return -1;
234 }
235
236 if (rx_buf && *rx_buf)
237 put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
238
239 return 1;
240}
241
242static unsigned int
243orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
244{
245 struct orion_spi *orion_spi;
246 unsigned int count;
247 int word_len;
248
249 orion_spi = spi_master_get_devdata(spi->master);
250 word_len = spi->bits_per_word;
251 count = xfer->len;
252
253 if (word_len == 8) {
254 const u8 *tx = xfer->tx_buf;
255 u8 *rx = xfer->rx_buf;
256
257 do {
258 if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
259 goto out;
260 count--;
261 } while (count);
262 } else if (word_len == 16) {
263 const u16 *tx = xfer->tx_buf;
264 u16 *rx = xfer->rx_buf;
265
266 do {
267 if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
268 goto out;
269 count -= 2;
270 } while (count);
271 }
272
273out:
274 return xfer->len - count;
275}
276
277
278static void orion_spi_work(struct work_struct *work)
279{
280 struct orion_spi *orion_spi =
281 container_of(work, struct orion_spi, work);
282
283 spin_lock_irq(&orion_spi->lock);
284 while (!list_empty(&orion_spi->msg_queue)) {
285 struct spi_message *m;
286 struct spi_device *spi;
287 struct spi_transfer *t = NULL;
288 int par_override = 0;
289 int status = 0;
290 int cs_active = 0;
291
292 m = container_of(orion_spi->msg_queue.next, struct spi_message,
293 queue);
294
295 list_del_init(&m->queue);
296 spin_unlock_irq(&orion_spi->lock);
297
298 spi = m->spi;
299
300 /* Load defaults */
301 status = orion_spi_setup_transfer(spi, NULL);
302
303 if (status < 0)
304 goto msg_done;
305
306 list_for_each_entry(t, &m->transfers, transfer_list) {
307 if (par_override || t->speed_hz || t->bits_per_word) {
308 par_override = 1;
309 status = orion_spi_setup_transfer(spi, t);
310 if (status < 0)
311 break;
312 if (!t->speed_hz && !t->bits_per_word)
313 par_override = 0;
314 }
315
316 if (!cs_active) {
317 orion_spi_set_cs(orion_spi, 1);
318 cs_active = 1;
319 }
320
321 if (t->len)
322 m->actual_length +=
323 orion_spi_write_read(spi, t);
324
325 if (t->delay_usecs)
326 udelay(t->delay_usecs);
327
328 if (t->cs_change) {
329 orion_spi_set_cs(orion_spi, 0);
330 cs_active = 0;
331 }
332 }
333
334msg_done:
335 if (cs_active)
336 orion_spi_set_cs(orion_spi, 0);
337
338 m->status = status;
339 m->complete(m->context);
340
341 spin_lock_irq(&orion_spi->lock);
342 }
343
344 spin_unlock_irq(&orion_spi->lock);
345}
346
347static int __init orion_spi_reset(struct orion_spi *orion_spi)
348{
349 /* Verify that the CS is deasserted */
350 orion_spi_set_cs(orion_spi, 0);
351
352 return 0;
353}
354
355static int orion_spi_setup(struct spi_device *spi)
356{
357 struct orion_spi *orion_spi;
358
359 orion_spi = spi_master_get_devdata(spi->master);
360
361 /* Fix ac timing if required. */
362 if (orion_spi->spi_info->enable_clock_fix)
363 orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
364 (1 << 14));
365
366 if ((spi->max_speed_hz == 0)
367 || (spi->max_speed_hz > orion_spi->max_speed))
368 spi->max_speed_hz = orion_spi->max_speed;
369
370 if (spi->max_speed_hz < orion_spi->min_speed) {
371 dev_err(&spi->dev, "setup: requested speed too low %d Hz\n",
372 spi->max_speed_hz);
373 return -EINVAL;
374 }
375
376 /*
377 * baudrate & width will be set orion_spi_setup_transfer
378 */
379 return 0;
380}
381
382static int orion_spi_transfer(struct spi_device *spi, struct spi_message *m)
383{
384 struct orion_spi *orion_spi;
385 struct spi_transfer *t = NULL;
386 unsigned long flags;
387
388 m->actual_length = 0;
389 m->status = 0;
390
391 /* reject invalid messages and transfers */
392 if (list_empty(&m->transfers) || !m->complete)
393 return -EINVAL;
394
395 orion_spi = spi_master_get_devdata(spi->master);
396
397 list_for_each_entry(t, &m->transfers, transfer_list) {
398 unsigned int bits_per_word = spi->bits_per_word;
399
400 if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
401 dev_err(&spi->dev,
402 "message rejected : "
403 "invalid transfer data buffers\n");
404 goto msg_rejected;
405 }
406
407 if (t->bits_per_word)
408 bits_per_word = t->bits_per_word;
409
410 if ((bits_per_word != 8) && (bits_per_word != 16)) {
411 dev_err(&spi->dev,
412 "message rejected : "
413 "invalid transfer bits_per_word (%d bits)\n",
414 bits_per_word);
415 goto msg_rejected;
416 }
417 /*make sure buffer length is even when working in 16 bit mode*/
418 if ((t->bits_per_word == 16) && (t->len & 1)) {
419 dev_err(&spi->dev,
420 "message rejected : "
421 "odd data length (%d) while in 16 bit mode\n",
422 t->len);
423 goto msg_rejected;
424 }
425
426 if (t->speed_hz && t->speed_hz < orion_spi->min_speed) {
427 dev_err(&spi->dev,
428 "message rejected : "
429 "device min speed (%d Hz) exceeds "
430 "required transfer speed (%d Hz)\n",
431 orion_spi->min_speed, t->speed_hz);
432 goto msg_rejected;
433 }
434 }
435
436
437 spin_lock_irqsave(&orion_spi->lock, flags);
438 list_add_tail(&m->queue, &orion_spi->msg_queue);
439 queue_work(orion_spi_wq, &orion_spi->work);
440 spin_unlock_irqrestore(&orion_spi->lock, flags);
441
442 return 0;
443msg_rejected:
444 /* Message rejected and not queued */
445 m->status = -EINVAL;
446 if (m->complete)
447 m->complete(m->context);
448 return -EINVAL;
449}
450
451static int __init orion_spi_probe(struct platform_device *pdev)
452{
453 struct spi_master *master;
454 struct orion_spi *spi;
455 struct resource *r;
456 struct orion_spi_info *spi_info;
457 int status = 0;
458
459 spi_info = pdev->dev.platform_data;
460
461 master = spi_alloc_master(&pdev->dev, sizeof *spi);
462 if (master == NULL) {
463 dev_dbg(&pdev->dev, "master allocation failed\n");
464 return -ENOMEM;
465 }
466
467 if (pdev->id != -1)
468 master->bus_num = pdev->id;
469
470 /* we support only mode 0, and no options */
471 master->mode_bits = 0;
472
473 master->setup = orion_spi_setup;
474 master->transfer = orion_spi_transfer;
475 master->num_chipselect = ORION_NUM_CHIPSELECTS;
476
477 dev_set_drvdata(&pdev->dev, master);
478
479 spi = spi_master_get_devdata(master);
480 spi->master = master;
481 spi->spi_info = spi_info;
482
483 spi->max_speed = DIV_ROUND_UP(spi_info->tclk, 4);
484 spi->min_speed = DIV_ROUND_UP(spi_info->tclk, 30);
485
486 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
487 if (r == NULL) {
488 status = -ENODEV;
489 goto out;
490 }
491
492 if (!request_mem_region(r->start, resource_size(r),
493 dev_name(&pdev->dev))) {
494 status = -EBUSY;
495 goto out;
496 }
497 spi->base = ioremap(r->start, SZ_1K);
498
499 INIT_WORK(&spi->work, orion_spi_work);
500
501 spin_lock_init(&spi->lock);
502 INIT_LIST_HEAD(&spi->msg_queue);
503
504 if (orion_spi_reset(spi) < 0)
505 goto out_rel_mem;
506
507 status = spi_register_master(master);
508 if (status < 0)
509 goto out_rel_mem;
510
511 return status;
512
513out_rel_mem:
514 release_mem_region(r->start, resource_size(r));
515
516out:
517 spi_master_put(master);
518 return status;
519}
520
521
522static int __exit orion_spi_remove(struct platform_device *pdev)
523{
524 struct spi_master *master;
525 struct orion_spi *spi;
526 struct resource *r;
527
528 master = dev_get_drvdata(&pdev->dev);
529 spi = spi_master_get_devdata(master);
530
531 cancel_work_sync(&spi->work);
532
533 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
534 release_mem_region(r->start, resource_size(r));
535
536 spi_unregister_master(master);
537
538 return 0;
539}
540
541MODULE_ALIAS("platform:" DRIVER_NAME);
542
543static struct platform_driver orion_spi_driver = {
544 .driver = {
545 .name = DRIVER_NAME,
546 .owner = THIS_MODULE,
547 },
548 .remove = __exit_p(orion_spi_remove),
549};
550
551static int __init orion_spi_init(void)
552{
553 orion_spi_wq = create_singlethread_workqueue(
554 orion_spi_driver.driver.name);
555 if (orion_spi_wq == NULL)
556 return -ENOMEM;
557
558 return platform_driver_probe(&orion_spi_driver, orion_spi_probe);
559}
560module_init(orion_spi_init);
561
562static void __exit orion_spi_exit(void)
563{
564 flush_workqueue(orion_spi_wq);
565 platform_driver_unregister(&orion_spi_driver);
566
567 destroy_workqueue(orion_spi_wq);
568}
569module_exit(orion_spi_exit);
570
571MODULE_DESCRIPTION("Orion SPI driver");
572MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
573MODULE_LICENSE("GPL");
1/*
2 * Marvell Orion SPI controller driver
3 *
4 * Author: Shadi Ammouri <shadi@marvell.com>
5 * Copyright (C) 2007-2008 Marvell Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/init.h>
13#include <linux/interrupt.h>
14#include <linux/delay.h>
15#include <linux/platform_device.h>
16#include <linux/err.h>
17#include <linux/io.h>
18#include <linux/spi/spi.h>
19#include <linux/module.h>
20#include <linux/clk.h>
21#include <asm/unaligned.h>
22
23#define DRIVER_NAME "orion_spi"
24
25#define ORION_NUM_CHIPSELECTS 1 /* only one slave is supported*/
26#define ORION_SPI_WAIT_RDY_MAX_LOOP 2000 /* in usec */
27
28#define ORION_SPI_IF_CTRL_REG 0x00
29#define ORION_SPI_IF_CONFIG_REG 0x04
30#define ORION_SPI_DATA_OUT_REG 0x08
31#define ORION_SPI_DATA_IN_REG 0x0c
32#define ORION_SPI_INT_CAUSE_REG 0x10
33
34#define ORION_SPI_IF_8_16_BIT_MODE (1 << 5)
35#define ORION_SPI_CLK_PRESCALE_MASK 0x1F
36
37struct orion_spi {
38 struct work_struct work;
39
40 /* Lock access to transfer list. */
41 spinlock_t lock;
42
43 struct list_head msg_queue;
44 struct spi_master *master;
45 void __iomem *base;
46 unsigned int max_speed;
47 unsigned int min_speed;
48 struct orion_spi_info *spi_info;
49 struct clk *clk;
50};
51
52static struct workqueue_struct *orion_spi_wq;
53
54static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
55{
56 return orion_spi->base + reg;
57}
58
59static inline void
60orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
61{
62 void __iomem *reg_addr = spi_reg(orion_spi, reg);
63 u32 val;
64
65 val = readl(reg_addr);
66 val |= mask;
67 writel(val, reg_addr);
68}
69
70static inline void
71orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
72{
73 void __iomem *reg_addr = spi_reg(orion_spi, reg);
74 u32 val;
75
76 val = readl(reg_addr);
77 val &= ~mask;
78 writel(val, reg_addr);
79}
80
81static int orion_spi_set_transfer_size(struct orion_spi *orion_spi, int size)
82{
83 if (size == 16) {
84 orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
85 ORION_SPI_IF_8_16_BIT_MODE);
86 } else if (size == 8) {
87 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
88 ORION_SPI_IF_8_16_BIT_MODE);
89 } else {
90 pr_debug("Bad bits per word value %d (only 8 or 16 are "
91 "allowed).\n", size);
92 return -EINVAL;
93 }
94
95 return 0;
96}
97
98static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
99{
100 u32 tclk_hz;
101 u32 rate;
102 u32 prescale;
103 u32 reg;
104 struct orion_spi *orion_spi;
105
106 orion_spi = spi_master_get_devdata(spi->master);
107
108 tclk_hz = clk_get_rate(orion_spi->clk);
109
110 /*
111 * the supported rates are: 4,6,8...30
112 * round up as we look for equal or less speed
113 */
114 rate = DIV_ROUND_UP(tclk_hz, speed);
115 rate = roundup(rate, 2);
116
117 /* check if requested speed is too small */
118 if (rate > 30)
119 return -EINVAL;
120
121 if (rate < 4)
122 rate = 4;
123
124 /* Convert the rate to SPI clock divisor value. */
125 prescale = 0x10 + rate/2;
126
127 reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
128 reg = ((reg & ~ORION_SPI_CLK_PRESCALE_MASK) | prescale);
129 writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
130
131 return 0;
132}
133
134/*
135 * called only when no transfer is active on the bus
136 */
137static int
138orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
139{
140 struct orion_spi *orion_spi;
141 unsigned int speed = spi->max_speed_hz;
142 unsigned int bits_per_word = spi->bits_per_word;
143 int rc;
144
145 orion_spi = spi_master_get_devdata(spi->master);
146
147 if ((t != NULL) && t->speed_hz)
148 speed = t->speed_hz;
149
150 if ((t != NULL) && t->bits_per_word)
151 bits_per_word = t->bits_per_word;
152
153 rc = orion_spi_baudrate_set(spi, speed);
154 if (rc)
155 return rc;
156
157 return orion_spi_set_transfer_size(orion_spi, bits_per_word);
158}
159
160static void orion_spi_set_cs(struct orion_spi *orion_spi, int enable)
161{
162 if (enable)
163 orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
164 else
165 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
166}
167
168static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
169{
170 int i;
171
172 for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
173 if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
174 return 1;
175 else
176 udelay(1);
177 }
178
179 return -1;
180}
181
182static inline int
183orion_spi_write_read_8bit(struct spi_device *spi,
184 const u8 **tx_buf, u8 **rx_buf)
185{
186 void __iomem *tx_reg, *rx_reg, *int_reg;
187 struct orion_spi *orion_spi;
188
189 orion_spi = spi_master_get_devdata(spi->master);
190 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
191 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
192 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
193
194 /* clear the interrupt cause register */
195 writel(0x0, int_reg);
196
197 if (tx_buf && *tx_buf)
198 writel(*(*tx_buf)++, tx_reg);
199 else
200 writel(0, tx_reg);
201
202 if (orion_spi_wait_till_ready(orion_spi) < 0) {
203 dev_err(&spi->dev, "TXS timed out\n");
204 return -1;
205 }
206
207 if (rx_buf && *rx_buf)
208 *(*rx_buf)++ = readl(rx_reg);
209
210 return 1;
211}
212
213static inline int
214orion_spi_write_read_16bit(struct spi_device *spi,
215 const u16 **tx_buf, u16 **rx_buf)
216{
217 void __iomem *tx_reg, *rx_reg, *int_reg;
218 struct orion_spi *orion_spi;
219
220 orion_spi = spi_master_get_devdata(spi->master);
221 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
222 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
223 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
224
225 /* clear the interrupt cause register */
226 writel(0x0, int_reg);
227
228 if (tx_buf && *tx_buf)
229 writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
230 else
231 writel(0, tx_reg);
232
233 if (orion_spi_wait_till_ready(orion_spi) < 0) {
234 dev_err(&spi->dev, "TXS timed out\n");
235 return -1;
236 }
237
238 if (rx_buf && *rx_buf)
239 put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
240
241 return 1;
242}
243
244static unsigned int
245orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
246{
247 struct orion_spi *orion_spi;
248 unsigned int count;
249 int word_len;
250
251 orion_spi = spi_master_get_devdata(spi->master);
252 word_len = spi->bits_per_word;
253 count = xfer->len;
254
255 if (word_len == 8) {
256 const u8 *tx = xfer->tx_buf;
257 u8 *rx = xfer->rx_buf;
258
259 do {
260 if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
261 goto out;
262 count--;
263 } while (count);
264 } else if (word_len == 16) {
265 const u16 *tx = xfer->tx_buf;
266 u16 *rx = xfer->rx_buf;
267
268 do {
269 if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
270 goto out;
271 count -= 2;
272 } while (count);
273 }
274
275out:
276 return xfer->len - count;
277}
278
279
280static void orion_spi_work(struct work_struct *work)
281{
282 struct orion_spi *orion_spi =
283 container_of(work, struct orion_spi, work);
284
285 spin_lock_irq(&orion_spi->lock);
286 while (!list_empty(&orion_spi->msg_queue)) {
287 struct spi_message *m;
288 struct spi_device *spi;
289 struct spi_transfer *t = NULL;
290 int par_override = 0;
291 int status = 0;
292 int cs_active = 0;
293
294 m = container_of(orion_spi->msg_queue.next, struct spi_message,
295 queue);
296
297 list_del_init(&m->queue);
298 spin_unlock_irq(&orion_spi->lock);
299
300 spi = m->spi;
301
302 /* Load defaults */
303 status = orion_spi_setup_transfer(spi, NULL);
304
305 if (status < 0)
306 goto msg_done;
307
308 list_for_each_entry(t, &m->transfers, transfer_list) {
309 if (par_override || t->speed_hz || t->bits_per_word) {
310 par_override = 1;
311 status = orion_spi_setup_transfer(spi, t);
312 if (status < 0)
313 break;
314 if (!t->speed_hz && !t->bits_per_word)
315 par_override = 0;
316 }
317
318 if (!cs_active) {
319 orion_spi_set_cs(orion_spi, 1);
320 cs_active = 1;
321 }
322
323 if (t->len)
324 m->actual_length +=
325 orion_spi_write_read(spi, t);
326
327 if (t->delay_usecs)
328 udelay(t->delay_usecs);
329
330 if (t->cs_change) {
331 orion_spi_set_cs(orion_spi, 0);
332 cs_active = 0;
333 }
334 }
335
336msg_done:
337 if (cs_active)
338 orion_spi_set_cs(orion_spi, 0);
339
340 m->status = status;
341 m->complete(m->context);
342
343 spin_lock_irq(&orion_spi->lock);
344 }
345
346 spin_unlock_irq(&orion_spi->lock);
347}
348
349static int __init orion_spi_reset(struct orion_spi *orion_spi)
350{
351 /* Verify that the CS is deasserted */
352 orion_spi_set_cs(orion_spi, 0);
353
354 return 0;
355}
356
357static int orion_spi_setup(struct spi_device *spi)
358{
359 struct orion_spi *orion_spi;
360
361 orion_spi = spi_master_get_devdata(spi->master);
362
363 if ((spi->max_speed_hz == 0)
364 || (spi->max_speed_hz > orion_spi->max_speed))
365 spi->max_speed_hz = orion_spi->max_speed;
366
367 if (spi->max_speed_hz < orion_spi->min_speed) {
368 dev_err(&spi->dev, "setup: requested speed too low %d Hz\n",
369 spi->max_speed_hz);
370 return -EINVAL;
371 }
372
373 /*
374 * baudrate & width will be set orion_spi_setup_transfer
375 */
376 return 0;
377}
378
379static int orion_spi_transfer(struct spi_device *spi, struct spi_message *m)
380{
381 struct orion_spi *orion_spi;
382 struct spi_transfer *t = NULL;
383 unsigned long flags;
384
385 m->actual_length = 0;
386 m->status = 0;
387
388 /* reject invalid messages and transfers */
389 if (list_empty(&m->transfers) || !m->complete)
390 return -EINVAL;
391
392 orion_spi = spi_master_get_devdata(spi->master);
393
394 list_for_each_entry(t, &m->transfers, transfer_list) {
395 unsigned int bits_per_word = spi->bits_per_word;
396
397 if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
398 dev_err(&spi->dev,
399 "message rejected : "
400 "invalid transfer data buffers\n");
401 goto msg_rejected;
402 }
403
404 if (t->bits_per_word)
405 bits_per_word = t->bits_per_word;
406
407 if ((bits_per_word != 8) && (bits_per_word != 16)) {
408 dev_err(&spi->dev,
409 "message rejected : "
410 "invalid transfer bits_per_word (%d bits)\n",
411 bits_per_word);
412 goto msg_rejected;
413 }
414 /*make sure buffer length is even when working in 16 bit mode*/
415 if ((t->bits_per_word == 16) && (t->len & 1)) {
416 dev_err(&spi->dev,
417 "message rejected : "
418 "odd data length (%d) while in 16 bit mode\n",
419 t->len);
420 goto msg_rejected;
421 }
422
423 if (t->speed_hz && t->speed_hz < orion_spi->min_speed) {
424 dev_err(&spi->dev,
425 "message rejected : "
426 "device min speed (%d Hz) exceeds "
427 "required transfer speed (%d Hz)\n",
428 orion_spi->min_speed, t->speed_hz);
429 goto msg_rejected;
430 }
431 }
432
433
434 spin_lock_irqsave(&orion_spi->lock, flags);
435 list_add_tail(&m->queue, &orion_spi->msg_queue);
436 queue_work(orion_spi_wq, &orion_spi->work);
437 spin_unlock_irqrestore(&orion_spi->lock, flags);
438
439 return 0;
440msg_rejected:
441 /* Message rejected and not queued */
442 m->status = -EINVAL;
443 if (m->complete)
444 m->complete(m->context);
445 return -EINVAL;
446}
447
448static int __init orion_spi_probe(struct platform_device *pdev)
449{
450 struct spi_master *master;
451 struct orion_spi *spi;
452 struct resource *r;
453 struct orion_spi_info *spi_info;
454 unsigned long tclk_hz;
455 int status = 0;
456
457 spi_info = pdev->dev.platform_data;
458
459 master = spi_alloc_master(&pdev->dev, sizeof *spi);
460 if (master == NULL) {
461 dev_dbg(&pdev->dev, "master allocation failed\n");
462 return -ENOMEM;
463 }
464
465 if (pdev->id != -1)
466 master->bus_num = pdev->id;
467
468 /* we support only mode 0, and no options */
469 master->mode_bits = 0;
470
471 master->setup = orion_spi_setup;
472 master->transfer = orion_spi_transfer;
473 master->num_chipselect = ORION_NUM_CHIPSELECTS;
474
475 dev_set_drvdata(&pdev->dev, master);
476
477 spi = spi_master_get_devdata(master);
478 spi->master = master;
479 spi->spi_info = spi_info;
480
481 spi->clk = clk_get(&pdev->dev, NULL);
482 if (IS_ERR(spi->clk)) {
483 status = PTR_ERR(spi->clk);
484 goto out;
485 }
486
487 clk_prepare(spi->clk);
488 clk_enable(spi->clk);
489 tclk_hz = clk_get_rate(spi->clk);
490 spi->max_speed = DIV_ROUND_UP(tclk_hz, 4);
491 spi->min_speed = DIV_ROUND_UP(tclk_hz, 30);
492
493 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
494 if (r == NULL) {
495 status = -ENODEV;
496 goto out_rel_clk;
497 }
498
499 if (!request_mem_region(r->start, resource_size(r),
500 dev_name(&pdev->dev))) {
501 status = -EBUSY;
502 goto out_rel_clk;
503 }
504 spi->base = ioremap(r->start, SZ_1K);
505
506 INIT_WORK(&spi->work, orion_spi_work);
507
508 spin_lock_init(&spi->lock);
509 INIT_LIST_HEAD(&spi->msg_queue);
510
511 if (orion_spi_reset(spi) < 0)
512 goto out_rel_mem;
513
514 status = spi_register_master(master);
515 if (status < 0)
516 goto out_rel_mem;
517
518 return status;
519
520out_rel_mem:
521 release_mem_region(r->start, resource_size(r));
522out_rel_clk:
523 clk_disable_unprepare(spi->clk);
524 clk_put(spi->clk);
525out:
526 spi_master_put(master);
527 return status;
528}
529
530
531static int __exit orion_spi_remove(struct platform_device *pdev)
532{
533 struct spi_master *master;
534 struct orion_spi *spi;
535 struct resource *r;
536
537 master = dev_get_drvdata(&pdev->dev);
538 spi = spi_master_get_devdata(master);
539
540 cancel_work_sync(&spi->work);
541
542 clk_disable_unprepare(spi->clk);
543 clk_put(spi->clk);
544
545 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
546 release_mem_region(r->start, resource_size(r));
547
548 spi_unregister_master(master);
549
550 return 0;
551}
552
553MODULE_ALIAS("platform:" DRIVER_NAME);
554
555static struct platform_driver orion_spi_driver = {
556 .driver = {
557 .name = DRIVER_NAME,
558 .owner = THIS_MODULE,
559 },
560 .remove = __exit_p(orion_spi_remove),
561};
562
563static int __init orion_spi_init(void)
564{
565 orion_spi_wq = create_singlethread_workqueue(
566 orion_spi_driver.driver.name);
567 if (orion_spi_wq == NULL)
568 return -ENOMEM;
569
570 return platform_driver_probe(&orion_spi_driver, orion_spi_probe);
571}
572module_init(orion_spi_init);
573
574static void __exit orion_spi_exit(void)
575{
576 flush_workqueue(orion_spi_wq);
577 platform_driver_unregister(&orion_spi_driver);
578
579 destroy_workqueue(orion_spi_wq);
580}
581module_exit(orion_spi_exit);
582
583MODULE_DESCRIPTION("Orion SPI driver");
584MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
585MODULE_LICENSE("GPL");