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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/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_device.h>
22#include <linux/clk.h>
23#include <linux/sizes.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_DATA_OUT_REG 0x08
42#define ORION_SPI_DATA_IN_REG 0x0c
43#define ORION_SPI_INT_CAUSE_REG 0x10
44#define ORION_SPI_TIMING_PARAMS_REG 0x18
45
46#define ORION_SPI_TMISO_SAMPLE_MASK (0x3 << 6)
47#define ORION_SPI_TMISO_SAMPLE_1 (1 << 6)
48#define ORION_SPI_TMISO_SAMPLE_2 (2 << 6)
49
50#define ORION_SPI_MODE_CPOL (1 << 11)
51#define ORION_SPI_MODE_CPHA (1 << 12)
52#define ORION_SPI_IF_8_16_BIT_MODE (1 << 5)
53#define ORION_SPI_CLK_PRESCALE_MASK 0x1F
54#define ARMADA_SPI_CLK_PRESCALE_MASK 0xDF
55#define ORION_SPI_MODE_MASK (ORION_SPI_MODE_CPOL | \
56 ORION_SPI_MODE_CPHA)
57#define ORION_SPI_CS_MASK 0x1C
58#define ORION_SPI_CS_SHIFT 2
59#define ORION_SPI_CS(cs) ((cs << ORION_SPI_CS_SHIFT) & \
60 ORION_SPI_CS_MASK)
61
62enum orion_spi_type {
63 ORION_SPI,
64 ARMADA_SPI,
65};
66
67struct orion_spi_dev {
68 enum orion_spi_type typ;
69 /*
70 * min_divisor and max_hz should be exclusive, the only we can
71 * have both is for managing the armada-370-spi case with old
72 * device tree
73 */
74 unsigned long max_hz;
75 unsigned int min_divisor;
76 unsigned int max_divisor;
77 u32 prescale_mask;
78 bool is_errata_50mhz_ac;
79};
80
81struct orion_spi {
82 struct spi_master *master;
83 void __iomem *base;
84 struct clk *clk;
85 const struct orion_spi_dev *devdata;
86};
87
88static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
89{
90 return orion_spi->base + reg;
91}
92
93static inline void
94orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
95{
96 void __iomem *reg_addr = spi_reg(orion_spi, reg);
97 u32 val;
98
99 val = readl(reg_addr);
100 val |= mask;
101 writel(val, reg_addr);
102}
103
104static inline void
105orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
106{
107 void __iomem *reg_addr = spi_reg(orion_spi, reg);
108 u32 val;
109
110 val = readl(reg_addr);
111 val &= ~mask;
112 writel(val, reg_addr);
113}
114
115static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
116{
117 u32 tclk_hz;
118 u32 rate;
119 u32 prescale;
120 u32 reg;
121 struct orion_spi *orion_spi;
122 const struct orion_spi_dev *devdata;
123
124 orion_spi = spi_master_get_devdata(spi->master);
125 devdata = orion_spi->devdata;
126
127 tclk_hz = clk_get_rate(orion_spi->clk);
128
129 if (devdata->typ == ARMADA_SPI) {
130 unsigned int clk, spr, sppr, sppr2, err;
131 unsigned int best_spr, best_sppr, best_err;
132
133 best_err = speed;
134 best_spr = 0;
135 best_sppr = 0;
136
137 /* Iterate over the valid range looking for best fit */
138 for (sppr = 0; sppr < 8; sppr++) {
139 sppr2 = 0x1 << sppr;
140
141 spr = tclk_hz / sppr2;
142 spr = DIV_ROUND_UP(spr, speed);
143 if ((spr == 0) || (spr > 15))
144 continue;
145
146 clk = tclk_hz / (spr * sppr2);
147 err = speed - clk;
148
149 if (err < best_err) {
150 best_spr = spr;
151 best_sppr = sppr;
152 best_err = err;
153 }
154 }
155
156 if ((best_sppr == 0) && (best_spr == 0))
157 return -EINVAL;
158
159 prescale = ((best_sppr & 0x6) << 5) |
160 ((best_sppr & 0x1) << 4) | best_spr;
161 } else {
162 /*
163 * the supported rates are: 4,6,8...30
164 * round up as we look for equal or less speed
165 */
166 rate = DIV_ROUND_UP(tclk_hz, speed);
167 rate = roundup(rate, 2);
168
169 /* check if requested speed is too small */
170 if (rate > 30)
171 return -EINVAL;
172
173 if (rate < 4)
174 rate = 4;
175
176 /* Convert the rate to SPI clock divisor value. */
177 prescale = 0x10 + rate/2;
178 }
179
180 reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
181 reg = ((reg & ~devdata->prescale_mask) | prescale);
182 writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
183
184 return 0;
185}
186
187static void
188orion_spi_mode_set(struct spi_device *spi)
189{
190 u32 reg;
191 struct orion_spi *orion_spi;
192
193 orion_spi = spi_master_get_devdata(spi->master);
194
195 reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
196 reg &= ~ORION_SPI_MODE_MASK;
197 if (spi->mode & SPI_CPOL)
198 reg |= ORION_SPI_MODE_CPOL;
199 if (spi->mode & SPI_CPHA)
200 reg |= ORION_SPI_MODE_CPHA;
201 writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
202}
203
204static void
205orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
206{
207 u32 reg;
208 struct orion_spi *orion_spi;
209
210 orion_spi = spi_master_get_devdata(spi->master);
211
212 /*
213 * Erratum description: (Erratum NO. FE-9144572) The device
214 * SPI interface supports frequencies of up to 50 MHz.
215 * However, due to this erratum, when the device core clock is
216 * 250 MHz and the SPI interfaces is configured for 50MHz SPI
217 * clock and CPOL=CPHA=1 there might occur data corruption on
218 * reads from the SPI device.
219 * Erratum Workaround:
220 * Work in one of the following configurations:
221 * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
222 * Register".
223 * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
224 * Register" before setting the interface.
225 */
226 reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
227 reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;
228
229 if (clk_get_rate(orion_spi->clk) == 250000000 &&
230 speed == 50000000 && spi->mode & SPI_CPOL &&
231 spi->mode & SPI_CPHA)
232 reg |= ORION_SPI_TMISO_SAMPLE_2;
233 else
234 reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */
235
236 writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
237}
238
239/*
240 * called only when no transfer is active on the bus
241 */
242static int
243orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
244{
245 struct orion_spi *orion_spi;
246 unsigned int speed = spi->max_speed_hz;
247 unsigned int bits_per_word = spi->bits_per_word;
248 int rc;
249
250 orion_spi = spi_master_get_devdata(spi->master);
251
252 if ((t != NULL) && t->speed_hz)
253 speed = t->speed_hz;
254
255 if ((t != NULL) && t->bits_per_word)
256 bits_per_word = t->bits_per_word;
257
258 orion_spi_mode_set(spi);
259
260 if (orion_spi->devdata->is_errata_50mhz_ac)
261 orion_spi_50mhz_ac_timing_erratum(spi, speed);
262
263 rc = orion_spi_baudrate_set(spi, speed);
264 if (rc)
265 return rc;
266
267 if (bits_per_word == 16)
268 orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
269 ORION_SPI_IF_8_16_BIT_MODE);
270 else
271 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
272 ORION_SPI_IF_8_16_BIT_MODE);
273
274 return 0;
275}
276
277static void orion_spi_set_cs(struct spi_device *spi, bool enable)
278{
279 struct orion_spi *orion_spi;
280
281 orion_spi = spi_master_get_devdata(spi->master);
282
283 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, ORION_SPI_CS_MASK);
284 orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG,
285 ORION_SPI_CS(spi->chip_select));
286
287 /* Chip select logic is inverted from spi_set_cs */
288 if (!enable)
289 orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
290 else
291 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
292}
293
294static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
295{
296 int i;
297
298 for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
299 if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
300 return 1;
301
302 udelay(1);
303 }
304
305 return -1;
306}
307
308static inline int
309orion_spi_write_read_8bit(struct spi_device *spi,
310 const u8 **tx_buf, u8 **rx_buf)
311{
312 void __iomem *tx_reg, *rx_reg, *int_reg;
313 struct orion_spi *orion_spi;
314
315 orion_spi = spi_master_get_devdata(spi->master);
316 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
317 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
318 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
319
320 /* clear the interrupt cause register */
321 writel(0x0, int_reg);
322
323 if (tx_buf && *tx_buf)
324 writel(*(*tx_buf)++, tx_reg);
325 else
326 writel(0, tx_reg);
327
328 if (orion_spi_wait_till_ready(orion_spi) < 0) {
329 dev_err(&spi->dev, "TXS timed out\n");
330 return -1;
331 }
332
333 if (rx_buf && *rx_buf)
334 *(*rx_buf)++ = readl(rx_reg);
335
336 return 1;
337}
338
339static inline int
340orion_spi_write_read_16bit(struct spi_device *spi,
341 const u16 **tx_buf, u16 **rx_buf)
342{
343 void __iomem *tx_reg, *rx_reg, *int_reg;
344 struct orion_spi *orion_spi;
345
346 orion_spi = spi_master_get_devdata(spi->master);
347 tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
348 rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
349 int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
350
351 /* clear the interrupt cause register */
352 writel(0x0, int_reg);
353
354 if (tx_buf && *tx_buf)
355 writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
356 else
357 writel(0, tx_reg);
358
359 if (orion_spi_wait_till_ready(orion_spi) < 0) {
360 dev_err(&spi->dev, "TXS timed out\n");
361 return -1;
362 }
363
364 if (rx_buf && *rx_buf)
365 put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
366
367 return 1;
368}
369
370static unsigned int
371orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
372{
373 unsigned int count;
374 int word_len;
375
376 word_len = spi->bits_per_word;
377 count = xfer->len;
378
379 if (word_len == 8) {
380 const u8 *tx = xfer->tx_buf;
381 u8 *rx = xfer->rx_buf;
382
383 do {
384 if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
385 goto out;
386 count--;
387 } while (count);
388 } else if (word_len == 16) {
389 const u16 *tx = xfer->tx_buf;
390 u16 *rx = xfer->rx_buf;
391
392 do {
393 if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
394 goto out;
395 count -= 2;
396 } while (count);
397 }
398
399out:
400 return xfer->len - count;
401}
402
403static int orion_spi_transfer_one(struct spi_master *master,
404 struct spi_device *spi,
405 struct spi_transfer *t)
406{
407 int status = 0;
408
409 status = orion_spi_setup_transfer(spi, t);
410 if (status < 0)
411 return status;
412
413 if (t->len)
414 orion_spi_write_read(spi, t);
415
416 return status;
417}
418
419static int orion_spi_setup(struct spi_device *spi)
420{
421 return orion_spi_setup_transfer(spi, NULL);
422}
423
424static int orion_spi_reset(struct orion_spi *orion_spi)
425{
426 /* Verify that the CS is deasserted */
427 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
428 return 0;
429}
430
431static const struct orion_spi_dev orion_spi_dev_data = {
432 .typ = ORION_SPI,
433 .min_divisor = 4,
434 .max_divisor = 30,
435 .prescale_mask = ORION_SPI_CLK_PRESCALE_MASK,
436};
437
438static const struct orion_spi_dev armada_370_spi_dev_data = {
439 .typ = ARMADA_SPI,
440 .min_divisor = 4,
441 .max_divisor = 1920,
442 .max_hz = 50000000,
443 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
444};
445
446static const struct orion_spi_dev armada_xp_spi_dev_data = {
447 .typ = ARMADA_SPI,
448 .max_hz = 50000000,
449 .max_divisor = 1920,
450 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
451};
452
453static const struct orion_spi_dev armada_375_spi_dev_data = {
454 .typ = ARMADA_SPI,
455 .min_divisor = 15,
456 .max_divisor = 1920,
457 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
458};
459
460static const struct orion_spi_dev armada_380_spi_dev_data = {
461 .typ = ARMADA_SPI,
462 .max_hz = 50000000,
463 .max_divisor = 1920,
464 .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
465 .is_errata_50mhz_ac = true,
466};
467
468static const struct of_device_id orion_spi_of_match_table[] = {
469 {
470 .compatible = "marvell,orion-spi",
471 .data = &orion_spi_dev_data,
472 },
473 {
474 .compatible = "marvell,armada-370-spi",
475 .data = &armada_370_spi_dev_data,
476 },
477 {
478 .compatible = "marvell,armada-375-spi",
479 .data = &armada_375_spi_dev_data,
480 },
481 {
482 .compatible = "marvell,armada-380-spi",
483 .data = &armada_380_spi_dev_data,
484 },
485 {
486 .compatible = "marvell,armada-390-spi",
487 .data = &armada_xp_spi_dev_data,
488 },
489 {
490 .compatible = "marvell,armada-xp-spi",
491 .data = &armada_xp_spi_dev_data,
492 },
493
494 {}
495};
496MODULE_DEVICE_TABLE(of, orion_spi_of_match_table);
497
498static int orion_spi_probe(struct platform_device *pdev)
499{
500 const struct of_device_id *of_id;
501 const struct orion_spi_dev *devdata;
502 struct spi_master *master;
503 struct orion_spi *spi;
504 struct resource *r;
505 unsigned long tclk_hz;
506 int status = 0;
507
508 master = spi_alloc_master(&pdev->dev, sizeof(*spi));
509 if (master == NULL) {
510 dev_dbg(&pdev->dev, "master allocation failed\n");
511 return -ENOMEM;
512 }
513
514 if (pdev->id != -1)
515 master->bus_num = pdev->id;
516 if (pdev->dev.of_node) {
517 u32 cell_index;
518
519 if (!of_property_read_u32(pdev->dev.of_node, "cell-index",
520 &cell_index))
521 master->bus_num = cell_index;
522 }
523
524 /* we support only mode 0, and no options */
525 master->mode_bits = SPI_CPHA | SPI_CPOL;
526 master->set_cs = orion_spi_set_cs;
527 master->transfer_one = orion_spi_transfer_one;
528 master->num_chipselect = ORION_NUM_CHIPSELECTS;
529 master->setup = orion_spi_setup;
530 master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
531 master->auto_runtime_pm = true;
532
533 platform_set_drvdata(pdev, master);
534
535 spi = spi_master_get_devdata(master);
536 spi->master = master;
537
538 of_id = of_match_device(orion_spi_of_match_table, &pdev->dev);
539 devdata = (of_id) ? of_id->data : &orion_spi_dev_data;
540 spi->devdata = devdata;
541
542 spi->clk = devm_clk_get(&pdev->dev, NULL);
543 if (IS_ERR(spi->clk)) {
544 status = PTR_ERR(spi->clk);
545 goto out;
546 }
547
548 status = clk_prepare_enable(spi->clk);
549 if (status)
550 goto out;
551
552 tclk_hz = clk_get_rate(spi->clk);
553
554 /*
555 * With old device tree, armada-370-spi could be used with
556 * Armada XP, however for this SoC the maximum frequency is
557 * 50MHz instead of tclk/4. On Armada 370, tclk cannot be
558 * higher than 200MHz. So, in order to be able to handle both
559 * SoCs, we can take the minimum of 50MHz and tclk/4.
560 */
561 if (of_device_is_compatible(pdev->dev.of_node,
562 "marvell,armada-370-spi"))
563 master->max_speed_hz = min(devdata->max_hz,
564 DIV_ROUND_UP(tclk_hz, devdata->min_divisor));
565 else if (devdata->min_divisor)
566 master->max_speed_hz =
567 DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
568 else
569 master->max_speed_hz = devdata->max_hz;
570 master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);
571
572 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
573 spi->base = devm_ioremap_resource(&pdev->dev, r);
574 if (IS_ERR(spi->base)) {
575 status = PTR_ERR(spi->base);
576 goto out_rel_clk;
577 }
578
579 pm_runtime_set_active(&pdev->dev);
580 pm_runtime_use_autosuspend(&pdev->dev);
581 pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
582 pm_runtime_enable(&pdev->dev);
583
584 status = orion_spi_reset(spi);
585 if (status < 0)
586 goto out_rel_pm;
587
588 pm_runtime_mark_last_busy(&pdev->dev);
589 pm_runtime_put_autosuspend(&pdev->dev);
590
591 master->dev.of_node = pdev->dev.of_node;
592 status = spi_register_master(master);
593 if (status < 0)
594 goto out_rel_pm;
595
596 return status;
597
598out_rel_pm:
599 pm_runtime_disable(&pdev->dev);
600out_rel_clk:
601 clk_disable_unprepare(spi->clk);
602out:
603 spi_master_put(master);
604 return status;
605}
606
607
608static int orion_spi_remove(struct platform_device *pdev)
609{
610 struct spi_master *master = platform_get_drvdata(pdev);
611 struct orion_spi *spi = spi_master_get_devdata(master);
612
613 pm_runtime_get_sync(&pdev->dev);
614 clk_disable_unprepare(spi->clk);
615
616 spi_unregister_master(master);
617 pm_runtime_disable(&pdev->dev);
618
619 return 0;
620}
621
622MODULE_ALIAS("platform:" DRIVER_NAME);
623
624#ifdef CONFIG_PM
625static int orion_spi_runtime_suspend(struct device *dev)
626{
627 struct spi_master *master = dev_get_drvdata(dev);
628 struct orion_spi *spi = spi_master_get_devdata(master);
629
630 clk_disable_unprepare(spi->clk);
631 return 0;
632}
633
634static int orion_spi_runtime_resume(struct device *dev)
635{
636 struct spi_master *master = dev_get_drvdata(dev);
637 struct orion_spi *spi = spi_master_get_devdata(master);
638
639 return clk_prepare_enable(spi->clk);
640}
641#endif
642
643static const struct dev_pm_ops orion_spi_pm_ops = {
644 SET_RUNTIME_PM_OPS(orion_spi_runtime_suspend,
645 orion_spi_runtime_resume,
646 NULL)
647};
648
649static struct platform_driver orion_spi_driver = {
650 .driver = {
651 .name = DRIVER_NAME,
652 .pm = &orion_spi_pm_ops,
653 .of_match_table = of_match_ptr(orion_spi_of_match_table),
654 },
655 .probe = orion_spi_probe,
656 .remove = orion_spi_remove,
657};
658
659module_platform_driver(orion_spi_driver);
660
661MODULE_DESCRIPTION("Orion SPI driver");
662MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
663MODULE_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");