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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// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Marvell Orion SPI controller driver
4 *
5 * Author: Shadi Ammouri <shadi@marvell.com>
6 * Copyright (C) 2007-2008 Marvell Ltd.
7 */
8
9#include <linux/interrupt.h>
10#include <linux/delay.h>
11#include <linux/platform_device.h>
12#include <linux/err.h>
13#include <linux/io.h>
14#include <linux/spi/spi.h>
15#include <linux/module.h>
16#include <linux/pm_runtime.h>
17#include <linux/of.h>
18#include <linux/of_address.h>
19#include <linux/of_device.h>
20#include <linux/of_gpio.h>
21#include <linux/clk.h>
22#include <linux/sizes.h>
23#include <linux/gpio.h>
24#include <asm/unaligned.h>
25
26#define DRIVER_NAME "orion_spi"
27
28/* Runtime PM autosuspend timeout: PM is fairly light on this driver */
29#define SPI_AUTOSUSPEND_TIMEOUT 200
30
31/* Some SoCs using this driver support up to 8 chip selects.
32 * It is up to the implementer to only use the chip selects
33 * that are available.
34 */
35#define ORION_NUM_CHIPSELECTS 8
36
37#define ORION_SPI_WAIT_RDY_MAX_LOOP 2000 /* in usec */
38
39#define ORION_SPI_IF_CTRL_REG 0x00
40#define ORION_SPI_IF_CONFIG_REG 0x04
41#define ORION_SPI_IF_RXLSBF BIT(14)
42#define ORION_SPI_IF_TXLSBF BIT(13)
43#define ORION_SPI_DATA_OUT_REG 0x08
44#define ORION_SPI_DATA_IN_REG 0x0c
45#define ORION_SPI_INT_CAUSE_REG 0x10
46#define ORION_SPI_TIMING_PARAMS_REG 0x18
47
48/* Register for the "Direct Mode" */
49#define SPI_DIRECT_WRITE_CONFIG_REG 0x20
50
51#define ORION_SPI_TMISO_SAMPLE_MASK (0x3 << 6)
52#define ORION_SPI_TMISO_SAMPLE_1 (1 << 6)
53#define ORION_SPI_TMISO_SAMPLE_2 (2 << 6)
54
55#define ORION_SPI_MODE_CPOL (1 << 11)
56#define ORION_SPI_MODE_CPHA (1 << 12)
57#define ORION_SPI_IF_8_16_BIT_MODE (1 << 5)
58#define ORION_SPI_CLK_PRESCALE_MASK 0x1F
59#define ARMADA_SPI_CLK_PRESCALE_MASK 0xDF
60#define ORION_SPI_MODE_MASK (ORION_SPI_MODE_CPOL | \
61 ORION_SPI_MODE_CPHA)
62#define ORION_SPI_CS_MASK 0x1C
63#define ORION_SPI_CS_SHIFT 2
64#define ORION_SPI_CS(cs) ((cs << ORION_SPI_CS_SHIFT) & \
65 ORION_SPI_CS_MASK)
66
67enum orion_spi_type {
68 ORION_SPI,
69 ARMADA_SPI,
70};
71
72struct orion_spi_dev {
73 enum orion_spi_type typ;
74 /*
75 * min_divisor and max_hz should be exclusive, the only we can
76 * have both is for managing the armada-370-spi case with old
77 * device tree
78 */
79 unsigned long max_hz;
80 unsigned int min_divisor;
81 unsigned int max_divisor;
82 u32 prescale_mask;
83 bool is_errata_50mhz_ac;
84};
85
86struct orion_direct_acc {
87 void __iomem *vaddr;
88 u32 size;
89};
90
91struct orion_child_options {
92 struct orion_direct_acc direct_access;
93};
94
95struct orion_spi {
96 struct spi_master *master;
97 void __iomem *base;
98 struct clk *clk;
99 struct clk *axi_clk;
100 const struct orion_spi_dev *devdata;
101 int unused_hw_gpio;
102
103 struct orion_child_options child[ORION_NUM_CHIPSELECTS];
104};
105
106static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
107{
108 return orion_spi->base + reg;
109}
110
111static inline void
112orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
113{
114 void __iomem *reg_addr = spi_reg(orion_spi, reg);
115 u32 val;
116
117 val = readl(reg_addr);
118 val |= mask;
119 writel(val, reg_addr);
120}
121
122static inline void
123orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
124{
125 void __iomem *reg_addr = spi_reg(orion_spi, reg);
126 u32 val;
127
128 val = readl(reg_addr);
129 val &= ~mask;
130 writel(val, reg_addr);
131}
132
133static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
134{
135 u32 tclk_hz;
136 u32 rate;
137 u32 prescale;
138 u32 reg;
139 struct orion_spi *orion_spi;
140 const struct orion_spi_dev *devdata;
141
142 orion_spi = spi_master_get_devdata(spi->master);
143 devdata = orion_spi->devdata;
144
145 tclk_hz = clk_get_rate(orion_spi->clk);
146
147 if (devdata->typ == ARMADA_SPI) {
148 /*
149 * Given the core_clk (tclk_hz) and the target rate (speed) we
150 * determine the best values for SPR (in [0 .. 15]) and SPPR (in
151 * [0..7]) such that
152 *
153 * core_clk / (SPR * 2 ** SPPR)
154 *
155 * is as big as possible but not bigger than speed.
156 */
157
158 /* best integer divider: */
159 unsigned divider = DIV_ROUND_UP(tclk_hz, speed);
160 unsigned spr, sppr;
161
162 if (divider < 16) {
163 /* This is the easy case, divider is less than 16 */
164 spr = divider;
165 sppr = 0;
166
167 } else {
168 unsigned two_pow_sppr;
169 /*
170 * Find the highest bit set in divider. This and the
171 * three next bits define SPR (apart from rounding).
172 * SPPR is then the number of zero bits that must be
173 * appended:
174 */
175 sppr = fls(divider) - 4;
176
177 /*
178 * As SPR only has 4 bits, we have to round divider up
179 * to the next multiple of 2 ** sppr.
180 */
181 two_pow_sppr = 1 << sppr;
182 divider = (divider + two_pow_sppr - 1) & -two_pow_sppr;
183
184 /*
185 * recalculate sppr as rounding up divider might have
186 * increased it enough to change the position of the
187 * highest set bit. In this case the bit that now
188 * doesn't make it into SPR is 0, so there is no need to
189 * round again.
190 */
191 sppr = fls(divider) - 4;
192 spr = divider >> sppr;
193
194 /*
195 * Now do range checking. SPR is constructed to have a
196 * width of 4 bits, so this is fine for sure. So we
197 * still need to check for sppr to fit into 3 bits:
198 */
199 if (sppr > 7)
200 return -EINVAL;
201 }
202
203 prescale = ((sppr & 0x6) << 5) | ((sppr & 0x1) << 4) | spr;
204 } else {
205 /*
206 * the supported rates are: 4,6,8...30
207 * round up as we look for equal or less speed
208 */
209 rate = DIV_ROUND_UP(tclk_hz, speed);
210 rate = roundup(rate, 2);
211
212 /* check if requested speed is too small */
213 if (rate > 30)
214 return -EINVAL;
215
216 if (rate < 4)
217 rate = 4;
218
219 /* Convert the rate to SPI clock divisor value. */
220 prescale = 0x10 + rate/2;
221 }
222
223 reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
224 reg = ((reg & ~devdata->prescale_mask) | prescale);
225 writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
226
227 return 0;
228}
229
230static void
231orion_spi_mode_set(struct spi_device *spi)
232{
233 u32 reg;
234 struct orion_spi *orion_spi;
235
236 orion_spi = spi_master_get_devdata(spi->master);
237
238 reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
239 reg &= ~ORION_SPI_MODE_MASK;
240 if (spi->mode & SPI_CPOL)
241 reg |= ORION_SPI_MODE_CPOL;
242 if (spi->mode & SPI_CPHA)
243 reg |= ORION_SPI_MODE_CPHA;
244 if (spi->mode & SPI_LSB_FIRST)
245 reg |= ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF;
246 else
247 reg &= ~(ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF);
248
249 writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
250}
251
252static void
253orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
254{
255 u32 reg;
256 struct orion_spi *orion_spi;
257
258 orion_spi = spi_master_get_devdata(spi->master);
259
260 /*
261 * Erratum description: (Erratum NO. FE-9144572) The device
262 * SPI interface supports frequencies of up to 50 MHz.
263 * However, due to this erratum, when the device core clock is
264 * 250 MHz and the SPI interfaces is configured for 50MHz SPI
265 * clock and CPOL=CPHA=1 there might occur data corruption on
266 * reads from the SPI device.
267 * Erratum Workaround:
268 * Work in one of the following configurations:
269 * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
270 * Register".
271 * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
272 * Register" before setting the interface.
273 */
274 reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
275 reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;
276
277 if (clk_get_rate(orion_spi->clk) == 250000000 &&
278 speed == 50000000 && spi->mode & SPI_CPOL &&
279 spi->mode & SPI_CPHA)
280 reg |= ORION_SPI_TMISO_SAMPLE_2;
281 else
282 reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */
283
284 writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
285}
286
287/*
288 * called only when no transfer is active on the bus
289 */
290static int
291orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
292{
293 struct orion_spi *orion_spi;
294 unsigned int speed = spi->max_speed_hz;
295 unsigned int bits_per_word = spi->bits_per_word;
296 int rc;
297
298 orion_spi = spi_master_get_devdata(spi->master);
299
300 if ((t != NULL) && t->speed_hz)
301 speed = t->speed_hz;
302
303 if ((t != NULL) && t->bits_per_word)
304 bits_per_word = t->bits_per_word;
305
306 orion_spi_mode_set(spi);
307
308 if (orion_spi->devdata->is_errata_50mhz_ac)
309 orion_spi_50mhz_ac_timing_erratum(spi, speed);
310
311 rc = orion_spi_baudrate_set(spi, speed);
312 if (rc)
313 return rc;
314
315 if (bits_per_word == 16)
316 orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
317 ORION_SPI_IF_8_16_BIT_MODE);
318 else
319 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
320 ORION_SPI_IF_8_16_BIT_MODE);
321
322 return 0;
323}
324
325static void orion_spi_set_cs(struct spi_device *spi, bool enable)
326{
327 struct orion_spi *orion_spi;
328 int cs;
329
330 orion_spi = spi_master_get_devdata(spi->master);
331
332 if (gpio_is_valid(spi->cs_gpio))
333 cs = orion_spi->unused_hw_gpio;
334 else
335 cs = spi->chip_select;
336
337 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, ORION_SPI_CS_MASK);
338 orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG,
339 ORION_SPI_CS(cs));
340
341 /* Chip select logic is inverted from spi_set_cs */
342 if (!enable)
343 orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
344 else
345 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
346}
347
348static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
349{
350 int i;
351
352 for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
353 if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
354 return 1;
355
356 udelay(1);
357 }
358
359 return -1;
360}
361
362static inline int
363orion_spi_write_read_8bit(struct spi_device *spi,
364 const u8 **tx_buf, u8 **rx_buf)
365{
366 void __iomem *tx_reg, *rx_reg, *int_reg;
367 struct orion_spi *orion_spi;
368
369 orion_spi = spi_master_get_devdata(spi->master);
370 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
371 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
372 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
373
374 /* clear the interrupt cause register */
375 writel(0x0, int_reg);
376
377 if (tx_buf && *tx_buf)
378 writel(*(*tx_buf)++, tx_reg);
379 else
380 writel(0, tx_reg);
381
382 if (orion_spi_wait_till_ready(orion_spi) < 0) {
383 dev_err(&spi->dev, "TXS timed out\n");
384 return -1;
385 }
386
387 if (rx_buf && *rx_buf)
388 *(*rx_buf)++ = readl(rx_reg);
389
390 return 1;
391}
392
393static inline int
394orion_spi_write_read_16bit(struct spi_device *spi,
395 const u16 **tx_buf, u16 **rx_buf)
396{
397 void __iomem *tx_reg, *rx_reg, *int_reg;
398 struct orion_spi *orion_spi;
399
400 orion_spi = spi_master_get_devdata(spi->master);
401 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
402 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
403 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
404
405 /* clear the interrupt cause register */
406 writel(0x0, int_reg);
407
408 if (tx_buf && *tx_buf)
409 writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
410 else
411 writel(0, tx_reg);
412
413 if (orion_spi_wait_till_ready(orion_spi) < 0) {
414 dev_err(&spi->dev, "TXS timed out\n");
415 return -1;
416 }
417
418 if (rx_buf && *rx_buf)
419 put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
420
421 return 1;
422}
423
424static unsigned int
425orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
426{
427 unsigned int count;
428 int word_len;
429 struct orion_spi *orion_spi;
430 int cs = spi->chip_select;
431 void __iomem *vaddr;
432
433 word_len = spi->bits_per_word;
434 count = xfer->len;
435
436 orion_spi = spi_master_get_devdata(spi->master);
437
438 /*
439 * Use SPI direct write mode if base address is available. Otherwise
440 * fall back to PIO mode for this transfer.
441 */
442 vaddr = orion_spi->child[cs].direct_access.vaddr;
443
444 if (vaddr && xfer->tx_buf && 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(vaddr, xfer->tx_buf, cnt);
453 if (rem) {
454 u32 *buf = (u32 *)xfer->tx_buf;
455
456 iowrite8_rep(vaddr, &buf[cnt], rem);
457 }
458
459 return count;
460 }
461
462 if (word_len == 8) {
463 const u8 *tx = xfer->tx_buf;
464 u8 *rx = xfer->rx_buf;
465
466 do {
467 if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
468 goto out;
469 count--;
470 if (xfer->word_delay_usecs)
471 udelay(xfer->word_delay_usecs);
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 if (xfer->word_delay_usecs)
482 udelay(xfer->word_delay_usecs);
483 } while (count);
484 }
485
486out:
487 return xfer->len - count;
488}
489
490static int orion_spi_transfer_one(struct spi_master *master,
491 struct spi_device *spi,
492 struct spi_transfer *t)
493{
494 int status = 0;
495
496 status = orion_spi_setup_transfer(spi, t);
497 if (status < 0)
498 return status;
499
500 if (t->len)
501 orion_spi_write_read(spi, t);
502
503 return status;
504}
505
506static int orion_spi_setup(struct spi_device *spi)
507{
508 if (gpio_is_valid(spi->cs_gpio)) {
509 gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
510 }
511 return orion_spi_setup_transfer(spi, NULL);
512}
513
514static int orion_spi_reset(struct orion_spi *orion_spi)
515{
516 /* Verify that the CS is deasserted */
517 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
518
519 /* Don't deassert CS between the direct mapped SPI transfers */
520 writel(0, spi_reg(orion_spi, SPI_DIRECT_WRITE_CONFIG_REG));
521
522 return 0;
523}
524
525static const struct orion_spi_dev orion_spi_dev_data = {
526 .typ = ORION_SPI,
527 .min_divisor = 4,
528 .max_divisor = 30,
529 .prescale_mask = ORION_SPI_CLK_PRESCALE_MASK,
530};
531
532static const struct orion_spi_dev armada_370_spi_dev_data = {
533 .typ = ARMADA_SPI,
534 .min_divisor = 4,
535 .max_divisor = 1920,
536 .max_hz = 50000000,
537 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
538};
539
540static const struct orion_spi_dev armada_xp_spi_dev_data = {
541 .typ = ARMADA_SPI,
542 .max_hz = 50000000,
543 .max_divisor = 1920,
544 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
545};
546
547static const struct orion_spi_dev armada_375_spi_dev_data = {
548 .typ = ARMADA_SPI,
549 .min_divisor = 15,
550 .max_divisor = 1920,
551 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
552};
553
554static const struct orion_spi_dev armada_380_spi_dev_data = {
555 .typ = ARMADA_SPI,
556 .max_hz = 50000000,
557 .max_divisor = 1920,
558 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
559 .is_errata_50mhz_ac = true,
560};
561
562static const struct of_device_id orion_spi_of_match_table[] = {
563 {
564 .compatible = "marvell,orion-spi",
565 .data = &orion_spi_dev_data,
566 },
567 {
568 .compatible = "marvell,armada-370-spi",
569 .data = &armada_370_spi_dev_data,
570 },
571 {
572 .compatible = "marvell,armada-375-spi",
573 .data = &armada_375_spi_dev_data,
574 },
575 {
576 .compatible = "marvell,armada-380-spi",
577 .data = &armada_380_spi_dev_data,
578 },
579 {
580 .compatible = "marvell,armada-390-spi",
581 .data = &armada_xp_spi_dev_data,
582 },
583 {
584 .compatible = "marvell,armada-xp-spi",
585 .data = &armada_xp_spi_dev_data,
586 },
587
588 {}
589};
590MODULE_DEVICE_TABLE(of, orion_spi_of_match_table);
591
592static int orion_spi_probe(struct platform_device *pdev)
593{
594 const struct of_device_id *of_id;
595 const struct orion_spi_dev *devdata;
596 struct spi_master *master;
597 struct orion_spi *spi;
598 struct resource *r;
599 unsigned long tclk_hz;
600 int status = 0;
601 struct device_node *np;
602
603 master = spi_alloc_master(&pdev->dev, sizeof(*spi));
604 if (master == NULL) {
605 dev_dbg(&pdev->dev, "master allocation failed\n");
606 return -ENOMEM;
607 }
608
609 if (pdev->id != -1)
610 master->bus_num = pdev->id;
611 if (pdev->dev.of_node) {
612 u32 cell_index;
613
614 if (!of_property_read_u32(pdev->dev.of_node, "cell-index",
615 &cell_index))
616 master->bus_num = cell_index;
617 }
618
619 /* we support all 4 SPI modes and LSB first option */
620 master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST;
621 master->set_cs = orion_spi_set_cs;
622 master->transfer_one = orion_spi_transfer_one;
623 master->num_chipselect = ORION_NUM_CHIPSELECTS;
624 master->setup = orion_spi_setup;
625 master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
626 master->auto_runtime_pm = true;
627 master->flags = SPI_MASTER_GPIO_SS;
628
629 platform_set_drvdata(pdev, master);
630
631 spi = spi_master_get_devdata(master);
632 spi->master = master;
633 spi->unused_hw_gpio = -1;
634
635 of_id = of_match_device(orion_spi_of_match_table, &pdev->dev);
636 devdata = (of_id) ? of_id->data : &orion_spi_dev_data;
637 spi->devdata = devdata;
638
639 spi->clk = devm_clk_get(&pdev->dev, NULL);
640 if (IS_ERR(spi->clk)) {
641 status = PTR_ERR(spi->clk);
642 goto out;
643 }
644
645 status = clk_prepare_enable(spi->clk);
646 if (status)
647 goto out;
648
649 /* The following clock is only used by some SoCs */
650 spi->axi_clk = devm_clk_get(&pdev->dev, "axi");
651 if (IS_ERR(spi->axi_clk) &&
652 PTR_ERR(spi->axi_clk) == -EPROBE_DEFER) {
653 status = -EPROBE_DEFER;
654 goto out_rel_clk;
655 }
656 if (!IS_ERR(spi->axi_clk))
657 clk_prepare_enable(spi->axi_clk);
658
659 tclk_hz = clk_get_rate(spi->clk);
660
661 /*
662 * With old device tree, armada-370-spi could be used with
663 * Armada XP, however for this SoC the maximum frequency is
664 * 50MHz instead of tclk/4. On Armada 370, tclk cannot be
665 * higher than 200MHz. So, in order to be able to handle both
666 * SoCs, we can take the minimum of 50MHz and tclk/4.
667 */
668 if (of_device_is_compatible(pdev->dev.of_node,
669 "marvell,armada-370-spi"))
670 master->max_speed_hz = min(devdata->max_hz,
671 DIV_ROUND_UP(tclk_hz, devdata->min_divisor));
672 else if (devdata->min_divisor)
673 master->max_speed_hz =
674 DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
675 else
676 master->max_speed_hz = devdata->max_hz;
677 master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);
678
679 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
680 spi->base = devm_ioremap_resource(&pdev->dev, r);
681 if (IS_ERR(spi->base)) {
682 status = PTR_ERR(spi->base);
683 goto out_rel_axi_clk;
684 }
685
686 for_each_available_child_of_node(pdev->dev.of_node, np) {
687 struct orion_direct_acc *dir_acc;
688 u32 cs;
689 int cs_gpio;
690
691 /* Get chip-select number from the "reg" property */
692 status = of_property_read_u32(np, "reg", &cs);
693 if (status) {
694 dev_err(&pdev->dev,
695 "%pOF has no valid 'reg' property (%d)\n",
696 np, status);
697 continue;
698 }
699
700 /*
701 * Initialize the CS GPIO:
702 * - properly request the actual GPIO signal
703 * - de-assert the logical signal so that all GPIO CS lines
704 * are inactive when probing for slaves
705 * - find an unused physical CS which will be driven for any
706 * slave which uses a CS GPIO
707 */
708 cs_gpio = of_get_named_gpio(pdev->dev.of_node, "cs-gpios", cs);
709 if (cs_gpio > 0) {
710 char *gpio_name;
711 int cs_flags;
712
713 if (spi->unused_hw_gpio == -1) {
714 dev_info(&pdev->dev,
715 "Selected unused HW CS#%d for any GPIO CSes\n",
716 cs);
717 spi->unused_hw_gpio = cs;
718 }
719
720 gpio_name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
721 "%s-CS%d", dev_name(&pdev->dev), cs);
722 if (!gpio_name) {
723 status = -ENOMEM;
724 goto out_rel_axi_clk;
725 }
726
727 cs_flags = of_property_read_bool(np, "spi-cs-high") ?
728 GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH;
729 status = devm_gpio_request_one(&pdev->dev, cs_gpio,
730 cs_flags, gpio_name);
731 if (status) {
732 dev_err(&pdev->dev,
733 "Can't request GPIO for CS %d\n", cs);
734 goto out_rel_axi_clk;
735 }
736 }
737
738 /*
739 * Check if an address is configured for this SPI device. If
740 * not, the MBus mapping via the 'ranges' property in the 'soc'
741 * node is not configured and this device should not use the
742 * direct mode. In this case, just continue with the next
743 * device.
744 */
745 status = of_address_to_resource(pdev->dev.of_node, cs + 1, r);
746 if (status)
747 continue;
748
749 /*
750 * Only map one page for direct access. This is enough for the
751 * simple TX transfer which only writes to the first word.
752 * This needs to get extended for the direct SPI-NOR / SPI-NAND
753 * support, once this gets implemented.
754 */
755 dir_acc = &spi->child[cs].direct_access;
756 dir_acc->vaddr = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);
757 if (!dir_acc->vaddr) {
758 status = -ENOMEM;
759 goto out_rel_axi_clk;
760 }
761 dir_acc->size = PAGE_SIZE;
762
763 dev_info(&pdev->dev, "CS%d configured for direct access\n", cs);
764 }
765
766 pm_runtime_set_active(&pdev->dev);
767 pm_runtime_use_autosuspend(&pdev->dev);
768 pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
769 pm_runtime_enable(&pdev->dev);
770
771 status = orion_spi_reset(spi);
772 if (status < 0)
773 goto out_rel_pm;
774
775 pm_runtime_mark_last_busy(&pdev->dev);
776 pm_runtime_put_autosuspend(&pdev->dev);
777
778 master->dev.of_node = pdev->dev.of_node;
779 status = spi_register_master(master);
780 if (status < 0)
781 goto out_rel_pm;
782
783 return status;
784
785out_rel_pm:
786 pm_runtime_disable(&pdev->dev);
787out_rel_axi_clk:
788 clk_disable_unprepare(spi->axi_clk);
789out_rel_clk:
790 clk_disable_unprepare(spi->clk);
791out:
792 spi_master_put(master);
793 return status;
794}
795
796
797static int orion_spi_remove(struct platform_device *pdev)
798{
799 struct spi_master *master = platform_get_drvdata(pdev);
800 struct orion_spi *spi = spi_master_get_devdata(master);
801
802 pm_runtime_get_sync(&pdev->dev);
803 clk_disable_unprepare(spi->axi_clk);
804 clk_disable_unprepare(spi->clk);
805
806 spi_unregister_master(master);
807 pm_runtime_disable(&pdev->dev);
808
809 return 0;
810}
811
812MODULE_ALIAS("platform:" DRIVER_NAME);
813
814#ifdef CONFIG_PM
815static int orion_spi_runtime_suspend(struct device *dev)
816{
817 struct spi_master *master = dev_get_drvdata(dev);
818 struct orion_spi *spi = spi_master_get_devdata(master);
819
820 clk_disable_unprepare(spi->axi_clk);
821 clk_disable_unprepare(spi->clk);
822 return 0;
823}
824
825static int orion_spi_runtime_resume(struct device *dev)
826{
827 struct spi_master *master = dev_get_drvdata(dev);
828 struct orion_spi *spi = spi_master_get_devdata(master);
829
830 if (!IS_ERR(spi->axi_clk))
831 clk_prepare_enable(spi->axi_clk);
832 return clk_prepare_enable(spi->clk);
833}
834#endif
835
836static const struct dev_pm_ops orion_spi_pm_ops = {
837 SET_RUNTIME_PM_OPS(orion_spi_runtime_suspend,
838 orion_spi_runtime_resume,
839 NULL)
840};
841
842static struct platform_driver orion_spi_driver = {
843 .driver = {
844 .name = DRIVER_NAME,
845 .pm = &orion_spi_pm_ops,
846 .of_match_table = of_match_ptr(orion_spi_of_match_table),
847 },
848 .probe = orion_spi_probe,
849 .remove = orion_spi_remove,
850};
851
852module_platform_driver(orion_spi_driver);
853
854MODULE_DESCRIPTION("Orion SPI driver");
855MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
856MODULE_LICENSE("GPL");