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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/interrupt.h>
13#include <linux/delay.h>
14#include <linux/platform_device.h>
15#include <linux/err.h>
16#include <linux/io.h>
17#include <linux/spi/spi.h>
18#include <linux/module.h>
19#include <linux/pm_runtime.h>
20#include <linux/of.h>
21#include <linux/of_address.h>
22#include <linux/of_device.h>
23#include <linux/clk.h>
24#include <linux/sizes.h>
25#include <linux/gpio.h>
26#include <asm/unaligned.h>
27
28#define DRIVER_NAME "orion_spi"
29
30/* Runtime PM autosuspend timeout: PM is fairly light on this driver */
31#define SPI_AUTOSUSPEND_TIMEOUT 200
32
33/* Some SoCs using this driver support up to 8 chip selects.
34 * It is up to the implementer to only use the chip selects
35 * that are available.
36 */
37#define ORION_NUM_CHIPSELECTS 8
38
39#define ORION_SPI_WAIT_RDY_MAX_LOOP 2000 /* in usec */
40
41#define ORION_SPI_IF_CTRL_REG 0x00
42#define ORION_SPI_IF_CONFIG_REG 0x04
43#define ORION_SPI_IF_RXLSBF BIT(14)
44#define ORION_SPI_IF_TXLSBF BIT(13)
45#define ORION_SPI_DATA_OUT_REG 0x08
46#define ORION_SPI_DATA_IN_REG 0x0c
47#define ORION_SPI_INT_CAUSE_REG 0x10
48#define ORION_SPI_TIMING_PARAMS_REG 0x18
49
50/* Register for the "Direct Mode" */
51#define SPI_DIRECT_WRITE_CONFIG_REG 0x20
52
53#define ORION_SPI_TMISO_SAMPLE_MASK (0x3 << 6)
54#define ORION_SPI_TMISO_SAMPLE_1 (1 << 6)
55#define ORION_SPI_TMISO_SAMPLE_2 (2 << 6)
56
57#define ORION_SPI_MODE_CPOL (1 << 11)
58#define ORION_SPI_MODE_CPHA (1 << 12)
59#define ORION_SPI_IF_8_16_BIT_MODE (1 << 5)
60#define ORION_SPI_CLK_PRESCALE_MASK 0x1F
61#define ARMADA_SPI_CLK_PRESCALE_MASK 0xDF
62#define ORION_SPI_MODE_MASK (ORION_SPI_MODE_CPOL | \
63 ORION_SPI_MODE_CPHA)
64#define ORION_SPI_CS_MASK 0x1C
65#define ORION_SPI_CS_SHIFT 2
66#define ORION_SPI_CS(cs) ((cs << ORION_SPI_CS_SHIFT) & \
67 ORION_SPI_CS_MASK)
68
69enum orion_spi_type {
70 ORION_SPI,
71 ARMADA_SPI,
72};
73
74struct orion_spi_dev {
75 enum orion_spi_type typ;
76 /*
77 * min_divisor and max_hz should be exclusive, the only we can
78 * have both is for managing the armada-370-spi case with old
79 * device tree
80 */
81 unsigned long max_hz;
82 unsigned int min_divisor;
83 unsigned int max_divisor;
84 u32 prescale_mask;
85 bool is_errata_50mhz_ac;
86};
87
88struct orion_direct_acc {
89 void __iomem *vaddr;
90 u32 size;
91};
92
93struct orion_child_options {
94 struct orion_direct_acc direct_access;
95};
96
97struct orion_spi {
98 struct spi_master *master;
99 void __iomem *base;
100 struct clk *clk;
101 struct clk *axi_clk;
102 const struct orion_spi_dev *devdata;
103 int unused_hw_gpio;
104
105 struct orion_child_options child[ORION_NUM_CHIPSELECTS];
106};
107
108static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
109{
110 return orion_spi->base + reg;
111}
112
113static inline void
114orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
115{
116 void __iomem *reg_addr = spi_reg(orion_spi, reg);
117 u32 val;
118
119 val = readl(reg_addr);
120 val |= mask;
121 writel(val, reg_addr);
122}
123
124static inline void
125orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
126{
127 void __iomem *reg_addr = spi_reg(orion_spi, reg);
128 u32 val;
129
130 val = readl(reg_addr);
131 val &= ~mask;
132 writel(val, reg_addr);
133}
134
135static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
136{
137 u32 tclk_hz;
138 u32 rate;
139 u32 prescale;
140 u32 reg;
141 struct orion_spi *orion_spi;
142 const struct orion_spi_dev *devdata;
143
144 orion_spi = spi_master_get_devdata(spi->master);
145 devdata = orion_spi->devdata;
146
147 tclk_hz = clk_get_rate(orion_spi->clk);
148
149 if (devdata->typ == ARMADA_SPI) {
150 /*
151 * Given the core_clk (tclk_hz) and the target rate (speed) we
152 * determine the best values for SPR (in [0 .. 15]) and SPPR (in
153 * [0..7]) such that
154 *
155 * core_clk / (SPR * 2 ** SPPR)
156 *
157 * is as big as possible but not bigger than speed.
158 */
159
160 /* best integer divider: */
161 unsigned divider = DIV_ROUND_UP(tclk_hz, speed);
162 unsigned spr, sppr;
163
164 if (divider < 16) {
165 /* This is the easy case, divider is less than 16 */
166 spr = divider;
167 sppr = 0;
168
169 } else {
170 unsigned two_pow_sppr;
171 /*
172 * Find the highest bit set in divider. This and the
173 * three next bits define SPR (apart from rounding).
174 * SPPR is then the number of zero bits that must be
175 * appended:
176 */
177 sppr = fls(divider) - 4;
178
179 /*
180 * As SPR only has 4 bits, we have to round divider up
181 * to the next multiple of 2 ** sppr.
182 */
183 two_pow_sppr = 1 << sppr;
184 divider = (divider + two_pow_sppr - 1) & -two_pow_sppr;
185
186 /*
187 * recalculate sppr as rounding up divider might have
188 * increased it enough to change the position of the
189 * highest set bit. In this case the bit that now
190 * doesn't make it into SPR is 0, so there is no need to
191 * round again.
192 */
193 sppr = fls(divider) - 4;
194 spr = divider >> sppr;
195
196 /*
197 * Now do range checking. SPR is constructed to have a
198 * width of 4 bits, so this is fine for sure. So we
199 * still need to check for sppr to fit into 3 bits:
200 */
201 if (sppr > 7)
202 return -EINVAL;
203 }
204
205 prescale = ((sppr & 0x6) << 5) | ((sppr & 0x1) << 4) | spr;
206 } else {
207 /*
208 * the supported rates are: 4,6,8...30
209 * round up as we look for equal or less speed
210 */
211 rate = DIV_ROUND_UP(tclk_hz, speed);
212 rate = roundup(rate, 2);
213
214 /* check if requested speed is too small */
215 if (rate > 30)
216 return -EINVAL;
217
218 if (rate < 4)
219 rate = 4;
220
221 /* Convert the rate to SPI clock divisor value. */
222 prescale = 0x10 + rate/2;
223 }
224
225 reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
226 reg = ((reg & ~devdata->prescale_mask) | prescale);
227 writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
228
229 return 0;
230}
231
232static void
233orion_spi_mode_set(struct spi_device *spi)
234{
235 u32 reg;
236 struct orion_spi *orion_spi;
237
238 orion_spi = spi_master_get_devdata(spi->master);
239
240 reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
241 reg &= ~ORION_SPI_MODE_MASK;
242 if (spi->mode & SPI_CPOL)
243 reg |= ORION_SPI_MODE_CPOL;
244 if (spi->mode & SPI_CPHA)
245 reg |= ORION_SPI_MODE_CPHA;
246 if (spi->mode & SPI_LSB_FIRST)
247 reg |= ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF;
248 else
249 reg &= ~(ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF);
250
251 writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
252}
253
254static void
255orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
256{
257 u32 reg;
258 struct orion_spi *orion_spi;
259
260 orion_spi = spi_master_get_devdata(spi->master);
261
262 /*
263 * Erratum description: (Erratum NO. FE-9144572) The device
264 * SPI interface supports frequencies of up to 50 MHz.
265 * However, due to this erratum, when the device core clock is
266 * 250 MHz and the SPI interfaces is configured for 50MHz SPI
267 * clock and CPOL=CPHA=1 there might occur data corruption on
268 * reads from the SPI device.
269 * Erratum Workaround:
270 * Work in one of the following configurations:
271 * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
272 * Register".
273 * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
274 * Register" before setting the interface.
275 */
276 reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
277 reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;
278
279 if (clk_get_rate(orion_spi->clk) == 250000000 &&
280 speed == 50000000 && spi->mode & SPI_CPOL &&
281 spi->mode & SPI_CPHA)
282 reg |= ORION_SPI_TMISO_SAMPLE_2;
283 else
284 reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */
285
286 writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
287}
288
289/*
290 * called only when no transfer is active on the bus
291 */
292static int
293orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
294{
295 struct orion_spi *orion_spi;
296 unsigned int speed = spi->max_speed_hz;
297 unsigned int bits_per_word = spi->bits_per_word;
298 int rc;
299
300 orion_spi = spi_master_get_devdata(spi->master);
301
302 if ((t != NULL) && t->speed_hz)
303 speed = t->speed_hz;
304
305 if ((t != NULL) && t->bits_per_word)
306 bits_per_word = t->bits_per_word;
307
308 orion_spi_mode_set(spi);
309
310 if (orion_spi->devdata->is_errata_50mhz_ac)
311 orion_spi_50mhz_ac_timing_erratum(spi, speed);
312
313 rc = orion_spi_baudrate_set(spi, speed);
314 if (rc)
315 return rc;
316
317 if (bits_per_word == 16)
318 orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
319 ORION_SPI_IF_8_16_BIT_MODE);
320 else
321 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
322 ORION_SPI_IF_8_16_BIT_MODE);
323
324 return 0;
325}
326
327static void orion_spi_set_cs(struct spi_device *spi, bool enable)
328{
329 struct orion_spi *orion_spi;
330 int cs;
331
332 orion_spi = spi_master_get_devdata(spi->master);
333
334 if (gpio_is_valid(spi->cs_gpio))
335 cs = orion_spi->unused_hw_gpio;
336 else
337 cs = spi->chip_select;
338
339 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, ORION_SPI_CS_MASK);
340 orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG,
341 ORION_SPI_CS(cs));
342
343 /* Chip select logic is inverted from spi_set_cs */
344 if (!enable)
345 orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
346 else
347 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
348}
349
350static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
351{
352 int i;
353
354 for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
355 if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
356 return 1;
357
358 udelay(1);
359 }
360
361 return -1;
362}
363
364static inline int
365orion_spi_write_read_8bit(struct spi_device *spi,
366 const u8 **tx_buf, u8 **rx_buf)
367{
368 void __iomem *tx_reg, *rx_reg, *int_reg;
369 struct orion_spi *orion_spi;
370
371 orion_spi = spi_master_get_devdata(spi->master);
372 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
373 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
374 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
375
376 /* clear the interrupt cause register */
377 writel(0x0, int_reg);
378
379 if (tx_buf && *tx_buf)
380 writel(*(*tx_buf)++, tx_reg);
381 else
382 writel(0, tx_reg);
383
384 if (orion_spi_wait_till_ready(orion_spi) < 0) {
385 dev_err(&spi->dev, "TXS timed out\n");
386 return -1;
387 }
388
389 if (rx_buf && *rx_buf)
390 *(*rx_buf)++ = readl(rx_reg);
391
392 return 1;
393}
394
395static inline int
396orion_spi_write_read_16bit(struct spi_device *spi,
397 const u16 **tx_buf, u16 **rx_buf)
398{
399 void __iomem *tx_reg, *rx_reg, *int_reg;
400 struct orion_spi *orion_spi;
401
402 orion_spi = spi_master_get_devdata(spi->master);
403 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
404 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
405 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
406
407 /* clear the interrupt cause register */
408 writel(0x0, int_reg);
409
410 if (tx_buf && *tx_buf)
411 writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
412 else
413 writel(0, tx_reg);
414
415 if (orion_spi_wait_till_ready(orion_spi) < 0) {
416 dev_err(&spi->dev, "TXS timed out\n");
417 return -1;
418 }
419
420 if (rx_buf && *rx_buf)
421 put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
422
423 return 1;
424}
425
426static unsigned int
427orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
428{
429 unsigned int count;
430 int word_len;
431 struct orion_spi *orion_spi;
432 int cs = spi->chip_select;
433
434 word_len = spi->bits_per_word;
435 count = xfer->len;
436
437 orion_spi = spi_master_get_devdata(spi->master);
438
439 /*
440 * Use SPI direct write mode if base address is available. Otherwise
441 * fall back to PIO mode for this transfer.
442 */
443 if ((orion_spi->child[cs].direct_access.vaddr) && (xfer->tx_buf) &&
444 (word_len == 8)) {
445 unsigned int cnt = count / 4;
446 unsigned int rem = count % 4;
447
448 /*
449 * Send the TX-data to the SPI device via the direct
450 * mapped address window
451 */
452 iowrite32_rep(orion_spi->child[cs].direct_access.vaddr,
453 xfer->tx_buf, cnt);
454 if (rem) {
455 u32 *buf = (u32 *)xfer->tx_buf;
456
457 iowrite8_rep(orion_spi->child[cs].direct_access.vaddr,
458 &buf[cnt], rem);
459 }
460
461 return count;
462 }
463
464 if (word_len == 8) {
465 const u8 *tx = xfer->tx_buf;
466 u8 *rx = xfer->rx_buf;
467
468 do {
469 if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
470 goto out;
471 count--;
472 } while (count);
473 } else if (word_len == 16) {
474 const u16 *tx = xfer->tx_buf;
475 u16 *rx = xfer->rx_buf;
476
477 do {
478 if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
479 goto out;
480 count -= 2;
481 } while (count);
482 }
483
484out:
485 return xfer->len - count;
486}
487
488static int orion_spi_transfer_one(struct spi_master *master,
489 struct spi_device *spi,
490 struct spi_transfer *t)
491{
492 int status = 0;
493
494 status = orion_spi_setup_transfer(spi, t);
495 if (status < 0)
496 return status;
497
498 if (t->len)
499 orion_spi_write_read(spi, t);
500
501 return status;
502}
503
504static int orion_spi_setup(struct spi_device *spi)
505{
506 if (gpio_is_valid(spi->cs_gpio)) {
507 gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
508 }
509 return orion_spi_setup_transfer(spi, NULL);
510}
511
512static int orion_spi_reset(struct orion_spi *orion_spi)
513{
514 /* Verify that the CS is deasserted */
515 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
516
517 /* Don't deassert CS between the direct mapped SPI transfers */
518 writel(0, spi_reg(orion_spi, SPI_DIRECT_WRITE_CONFIG_REG));
519
520 return 0;
521}
522
523static const struct orion_spi_dev orion_spi_dev_data = {
524 .typ = ORION_SPI,
525 .min_divisor = 4,
526 .max_divisor = 30,
527 .prescale_mask = ORION_SPI_CLK_PRESCALE_MASK,
528};
529
530static const struct orion_spi_dev armada_370_spi_dev_data = {
531 .typ = ARMADA_SPI,
532 .min_divisor = 4,
533 .max_divisor = 1920,
534 .max_hz = 50000000,
535 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
536};
537
538static const struct orion_spi_dev armada_xp_spi_dev_data = {
539 .typ = ARMADA_SPI,
540 .max_hz = 50000000,
541 .max_divisor = 1920,
542 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
543};
544
545static const struct orion_spi_dev armada_375_spi_dev_data = {
546 .typ = ARMADA_SPI,
547 .min_divisor = 15,
548 .max_divisor = 1920,
549 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
550};
551
552static const struct orion_spi_dev armada_380_spi_dev_data = {
553 .typ = ARMADA_SPI,
554 .max_hz = 50000000,
555 .max_divisor = 1920,
556 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
557 .is_errata_50mhz_ac = true,
558};
559
560static const struct of_device_id orion_spi_of_match_table[] = {
561 {
562 .compatible = "marvell,orion-spi",
563 .data = &orion_spi_dev_data,
564 },
565 {
566 .compatible = "marvell,armada-370-spi",
567 .data = &armada_370_spi_dev_data,
568 },
569 {
570 .compatible = "marvell,armada-375-spi",
571 .data = &armada_375_spi_dev_data,
572 },
573 {
574 .compatible = "marvell,armada-380-spi",
575 .data = &armada_380_spi_dev_data,
576 },
577 {
578 .compatible = "marvell,armada-390-spi",
579 .data = &armada_xp_spi_dev_data,
580 },
581 {
582 .compatible = "marvell,armada-xp-spi",
583 .data = &armada_xp_spi_dev_data,
584 },
585
586 {}
587};
588MODULE_DEVICE_TABLE(of, orion_spi_of_match_table);
589
590static int orion_spi_probe(struct platform_device *pdev)
591{
592 const struct of_device_id *of_id;
593 const struct orion_spi_dev *devdata;
594 struct spi_master *master;
595 struct orion_spi *spi;
596 struct resource *r;
597 unsigned long tclk_hz;
598 int status = 0;
599 struct device_node *np;
600
601 master = spi_alloc_master(&pdev->dev, sizeof(*spi));
602 if (master == NULL) {
603 dev_dbg(&pdev->dev, "master allocation failed\n");
604 return -ENOMEM;
605 }
606
607 if (pdev->id != -1)
608 master->bus_num = pdev->id;
609 if (pdev->dev.of_node) {
610 u32 cell_index;
611
612 if (!of_property_read_u32(pdev->dev.of_node, "cell-index",
613 &cell_index))
614 master->bus_num = cell_index;
615 }
616
617 /* we support all 4 SPI modes and LSB first option */
618 master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST;
619 master->set_cs = orion_spi_set_cs;
620 master->transfer_one = orion_spi_transfer_one;
621 master->num_chipselect = ORION_NUM_CHIPSELECTS;
622 master->setup = orion_spi_setup;
623 master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
624 master->auto_runtime_pm = true;
625 master->flags = SPI_MASTER_GPIO_SS;
626
627 platform_set_drvdata(pdev, master);
628
629 spi = spi_master_get_devdata(master);
630 spi->master = master;
631 spi->unused_hw_gpio = -1;
632
633 of_id = of_match_device(orion_spi_of_match_table, &pdev->dev);
634 devdata = (of_id) ? of_id->data : &orion_spi_dev_data;
635 spi->devdata = devdata;
636
637 spi->clk = devm_clk_get(&pdev->dev, NULL);
638 if (IS_ERR(spi->clk)) {
639 status = PTR_ERR(spi->clk);
640 goto out;
641 }
642
643 status = clk_prepare_enable(spi->clk);
644 if (status)
645 goto out;
646
647 /* The following clock is only used by some SoCs */
648 spi->axi_clk = devm_clk_get(&pdev->dev, "axi");
649 if (IS_ERR(spi->axi_clk) &&
650 PTR_ERR(spi->axi_clk) == -EPROBE_DEFER) {
651 status = -EPROBE_DEFER;
652 goto out_rel_clk;
653 }
654 if (!IS_ERR(spi->axi_clk))
655 clk_prepare_enable(spi->axi_clk);
656
657 tclk_hz = clk_get_rate(spi->clk);
658
659 /*
660 * With old device tree, armada-370-spi could be used with
661 * Armada XP, however for this SoC the maximum frequency is
662 * 50MHz instead of tclk/4. On Armada 370, tclk cannot be
663 * higher than 200MHz. So, in order to be able to handle both
664 * SoCs, we can take the minimum of 50MHz and tclk/4.
665 */
666 if (of_device_is_compatible(pdev->dev.of_node,
667 "marvell,armada-370-spi"))
668 master->max_speed_hz = min(devdata->max_hz,
669 DIV_ROUND_UP(tclk_hz, devdata->min_divisor));
670 else if (devdata->min_divisor)
671 master->max_speed_hz =
672 DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
673 else
674 master->max_speed_hz = devdata->max_hz;
675 master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);
676
677 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
678 spi->base = devm_ioremap_resource(&pdev->dev, r);
679 if (IS_ERR(spi->base)) {
680 status = PTR_ERR(spi->base);
681 goto out_rel_axi_clk;
682 }
683
684 /* Scan all SPI devices of this controller for direct mapped devices */
685 for_each_available_child_of_node(pdev->dev.of_node, np) {
686 u32 cs;
687
688 /* Get chip-select number from the "reg" property */
689 status = of_property_read_u32(np, "reg", &cs);
690 if (status) {
691 dev_err(&pdev->dev,
692 "%pOF has no valid 'reg' property (%d)\n",
693 np, status);
694 continue;
695 }
696
697 /*
698 * Check if an address is configured for this SPI device. If
699 * not, the MBus mapping via the 'ranges' property in the 'soc'
700 * node is not configured and this device should not use the
701 * direct mode. In this case, just continue with the next
702 * device.
703 */
704 status = of_address_to_resource(pdev->dev.of_node, cs + 1, r);
705 if (status)
706 continue;
707
708 /*
709 * Only map one page for direct access. This is enough for the
710 * simple TX transfer which only writes to the first word.
711 * This needs to get extended for the direct SPI-NOR / SPI-NAND
712 * support, once this gets implemented.
713 */
714 spi->child[cs].direct_access.vaddr = devm_ioremap(&pdev->dev,
715 r->start,
716 PAGE_SIZE);
717 if (!spi->child[cs].direct_access.vaddr) {
718 status = -ENOMEM;
719 goto out_rel_axi_clk;
720 }
721 spi->child[cs].direct_access.size = PAGE_SIZE;
722
723 dev_info(&pdev->dev, "CS%d configured for direct access\n", cs);
724 }
725
726 pm_runtime_set_active(&pdev->dev);
727 pm_runtime_use_autosuspend(&pdev->dev);
728 pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
729 pm_runtime_enable(&pdev->dev);
730
731 status = orion_spi_reset(spi);
732 if (status < 0)
733 goto out_rel_pm;
734
735 pm_runtime_mark_last_busy(&pdev->dev);
736 pm_runtime_put_autosuspend(&pdev->dev);
737
738 master->dev.of_node = pdev->dev.of_node;
739 status = spi_register_master(master);
740 if (status < 0)
741 goto out_rel_pm;
742
743 if (master->cs_gpios) {
744 int i;
745 for (i = 0; i < master->num_chipselect; ++i) {
746 char *gpio_name;
747
748 if (!gpio_is_valid(master->cs_gpios[i])) {
749 continue;
750 }
751
752 gpio_name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
753 "%s-CS%d", dev_name(&pdev->dev), i);
754 if (!gpio_name) {
755 status = -ENOMEM;
756 goto out_rel_master;
757 }
758
759 status = devm_gpio_request(&pdev->dev,
760 master->cs_gpios[i], gpio_name);
761 if (status) {
762 dev_err(&pdev->dev,
763 "Can't request GPIO for CS %d\n",
764 master->cs_gpios[i]);
765 goto out_rel_master;
766 }
767 if (spi->unused_hw_gpio == -1) {
768 dev_info(&pdev->dev,
769 "Selected unused HW CS#%d for any GPIO CSes\n",
770 i);
771 spi->unused_hw_gpio = i;
772 }
773 }
774 }
775
776
777 return status;
778
779out_rel_master:
780 spi_unregister_master(master);
781out_rel_pm:
782 pm_runtime_disable(&pdev->dev);
783out_rel_axi_clk:
784 clk_disable_unprepare(spi->axi_clk);
785out_rel_clk:
786 clk_disable_unprepare(spi->clk);
787out:
788 spi_master_put(master);
789 return status;
790}
791
792
793static int orion_spi_remove(struct platform_device *pdev)
794{
795 struct spi_master *master = platform_get_drvdata(pdev);
796 struct orion_spi *spi = spi_master_get_devdata(master);
797
798 pm_runtime_get_sync(&pdev->dev);
799 clk_disable_unprepare(spi->axi_clk);
800 clk_disable_unprepare(spi->clk);
801
802 spi_unregister_master(master);
803 pm_runtime_disable(&pdev->dev);
804
805 return 0;
806}
807
808MODULE_ALIAS("platform:" DRIVER_NAME);
809
810#ifdef CONFIG_PM
811static int orion_spi_runtime_suspend(struct device *dev)
812{
813 struct spi_master *master = dev_get_drvdata(dev);
814 struct orion_spi *spi = spi_master_get_devdata(master);
815
816 clk_disable_unprepare(spi->axi_clk);
817 clk_disable_unprepare(spi->clk);
818 return 0;
819}
820
821static int orion_spi_runtime_resume(struct device *dev)
822{
823 struct spi_master *master = dev_get_drvdata(dev);
824 struct orion_spi *spi = spi_master_get_devdata(master);
825
826 if (!IS_ERR(spi->axi_clk))
827 clk_prepare_enable(spi->axi_clk);
828 return clk_prepare_enable(spi->clk);
829}
830#endif
831
832static const struct dev_pm_ops orion_spi_pm_ops = {
833 SET_RUNTIME_PM_OPS(orion_spi_runtime_suspend,
834 orion_spi_runtime_resume,
835 NULL)
836};
837
838static struct platform_driver orion_spi_driver = {
839 .driver = {
840 .name = DRIVER_NAME,
841 .pm = &orion_spi_pm_ops,
842 .of_match_table = of_match_ptr(orion_spi_of_match_table),
843 },
844 .probe = orion_spi_probe,
845 .remove = orion_spi_remove,
846};
847
848module_platform_driver(orion_spi_driver);
849
850MODULE_DESCRIPTION("Orion SPI driver");
851MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
852MODULE_LICENSE("GPL");