2 * SuperH MSIOF SPI Master Interface
4 * Copyright (c) 2009 Magnus Damm
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/delay.h>
15 #include <linux/interrupt.h>
16 #include <linux/platform_device.h>
17 #include <linux/completion.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/gpio.h>
20 #include <linux/bitmap.h>
21 #include <linux/clk.h>
23 #include <linux/err.h>
25 #include <linux/spi/spi.h>
26 #include <linux/spi/spi_bitbang.h>
27 #include <linux/spi/sh_msiof.h>
29 #include <asm/unaligned.h>
31 struct sh_msiof_spi_priv
{
32 struct spi_bitbang bitbang
; /* must be first for spi_bitbang.c */
33 void __iomem
*mapbase
;
35 struct platform_device
*pdev
;
36 struct sh_msiof_spi_info
*info
;
37 struct completion done
;
62 #define CTR_TSCKE (1 << 15)
63 #define CTR_TFSE (1 << 14)
64 #define CTR_TXE (1 << 9)
65 #define CTR_RXE (1 << 8)
67 #define STR_TEOF (1 << 23)
68 #define STR_REOF (1 << 7)
70 static unsigned long sh_msiof_read(struct sh_msiof_spi_priv
*p
, int reg_offs
)
75 return ioread16(p
->mapbase
+ reg_offs
);
77 return ioread32(p
->mapbase
+ reg_offs
);
81 static void sh_msiof_write(struct sh_msiof_spi_priv
*p
, int reg_offs
,
87 iowrite16(value
, p
->mapbase
+ reg_offs
);
90 iowrite32(value
, p
->mapbase
+ reg_offs
);
95 static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv
*p
,
96 unsigned long clr
, unsigned long set
)
98 unsigned long mask
= clr
| set
;
102 data
= sh_msiof_read(p
, CTR
);
105 sh_msiof_write(p
, CTR
, data
);
107 for (k
= 100; k
> 0; k
--) {
108 if ((sh_msiof_read(p
, CTR
) & mask
) == set
)
114 return k
> 0 ? 0 : -ETIMEDOUT
;
117 static irqreturn_t
sh_msiof_spi_irq(int irq
, void *data
)
119 struct sh_msiof_spi_priv
*p
= data
;
121 /* just disable the interrupt and wake up */
122 sh_msiof_write(p
, IER
, 0);
131 } const sh_msiof_spi_clk_table
[] = {
145 static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv
*p
,
146 unsigned long parent_rate
,
147 unsigned long spi_hz
)
149 unsigned long div
= 1024;
152 if (!WARN_ON(!spi_hz
|| !parent_rate
))
153 div
= parent_rate
/ spi_hz
;
155 /* TODO: make more fine grained */
157 for (k
= 0; k
< ARRAY_SIZE(sh_msiof_spi_clk_table
); k
++) {
158 if (sh_msiof_spi_clk_table
[k
].div
>= div
)
162 k
= min_t(int, k
, ARRAY_SIZE(sh_msiof_spi_clk_table
) - 1);
164 sh_msiof_write(p
, TSCR
, sh_msiof_spi_clk_table
[k
].scr
);
165 sh_msiof_write(p
, RSCR
, sh_msiof_spi_clk_table
[k
].scr
);
168 static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv
*p
,
170 int tx_hi_z
, int lsb_first
)
176 * CPOL CPHA TSCKIZ RSCKIZ TEDG REDG
182 sh_msiof_write(p
, FCTR
, 0);
183 sh_msiof_write(p
, TMDR1
, 0xe2000005 | (lsb_first
<< 24));
184 sh_msiof_write(p
, RMDR1
, 0x22000005 | (lsb_first
<< 24));
187 tmp
|= cpol
<< 30; /* TSCKIZ */
188 tmp
|= cpol
<< 28; /* RSCKIZ */
190 edge
= cpol
? cpha
: !cpha
;
192 tmp
|= edge
<< 27; /* TEDG */
193 tmp
|= edge
<< 26; /* REDG */
194 tmp
|= (tx_hi_z
? 2 : 0) << 22; /* TXDIZ */
195 sh_msiof_write(p
, CTR
, tmp
);
198 static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv
*p
,
199 const void *tx_buf
, void *rx_buf
,
204 dr2
= ((bits
- 1) << 24) | ((words
- 1) << 16);
207 sh_msiof_write(p
, TMDR2
, dr2
);
209 sh_msiof_write(p
, TMDR2
, dr2
| 1);
212 sh_msiof_write(p
, RMDR2
, dr2
);
214 sh_msiof_write(p
, IER
, STR_TEOF
| STR_REOF
);
217 static void sh_msiof_reset_str(struct sh_msiof_spi_priv
*p
)
219 sh_msiof_write(p
, STR
, sh_msiof_read(p
, STR
));
222 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv
*p
,
223 const void *tx_buf
, int words
, int fs
)
225 const unsigned char *buf_8
= tx_buf
;
228 for (k
= 0; k
< words
; k
++)
229 sh_msiof_write(p
, TFDR
, buf_8
[k
] << fs
);
232 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv
*p
,
233 const void *tx_buf
, int words
, int fs
)
235 const unsigned short *buf_16
= tx_buf
;
238 for (k
= 0; k
< words
; k
++)
239 sh_msiof_write(p
, TFDR
, buf_16
[k
] << fs
);
242 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv
*p
,
243 const void *tx_buf
, int words
, int fs
)
245 const unsigned short *buf_16
= tx_buf
;
248 for (k
= 0; k
< words
; k
++)
249 sh_msiof_write(p
, TFDR
, get_unaligned(&buf_16
[k
]) << fs
);
252 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv
*p
,
253 const void *tx_buf
, int words
, int fs
)
255 const unsigned int *buf_32
= tx_buf
;
258 for (k
= 0; k
< words
; k
++)
259 sh_msiof_write(p
, TFDR
, buf_32
[k
] << fs
);
262 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv
*p
,
263 const void *tx_buf
, int words
, int fs
)
265 const unsigned int *buf_32
= tx_buf
;
268 for (k
= 0; k
< words
; k
++)
269 sh_msiof_write(p
, TFDR
, get_unaligned(&buf_32
[k
]) << fs
);
272 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv
*p
,
273 void *rx_buf
, int words
, int fs
)
275 unsigned char *buf_8
= rx_buf
;
278 for (k
= 0; k
< words
; k
++)
279 buf_8
[k
] = sh_msiof_read(p
, RFDR
) >> fs
;
282 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv
*p
,
283 void *rx_buf
, int words
, int fs
)
285 unsigned short *buf_16
= rx_buf
;
288 for (k
= 0; k
< words
; k
++)
289 buf_16
[k
] = sh_msiof_read(p
, RFDR
) >> fs
;
292 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv
*p
,
293 void *rx_buf
, int words
, int fs
)
295 unsigned short *buf_16
= rx_buf
;
298 for (k
= 0; k
< words
; k
++)
299 put_unaligned(sh_msiof_read(p
, RFDR
) >> fs
, &buf_16
[k
]);
302 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv
*p
,
303 void *rx_buf
, int words
, int fs
)
305 unsigned int *buf_32
= rx_buf
;
308 for (k
= 0; k
< words
; k
++)
309 buf_32
[k
] = sh_msiof_read(p
, RFDR
) >> fs
;
312 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv
*p
,
313 void *rx_buf
, int words
, int fs
)
315 unsigned int *buf_32
= rx_buf
;
318 for (k
= 0; k
< words
; k
++)
319 put_unaligned(sh_msiof_read(p
, RFDR
) >> fs
, &buf_32
[k
]);
322 static int sh_msiof_spi_bits(struct spi_device
*spi
, struct spi_transfer
*t
)
326 bits
= t
? t
->bits_per_word
: 0;
327 bits
= bits
? bits
: spi
->bits_per_word
;
331 static unsigned long sh_msiof_spi_hz(struct spi_device
*spi
,
332 struct spi_transfer
*t
)
336 hz
= t
? t
->speed_hz
: 0;
337 hz
= hz
? hz
: spi
->max_speed_hz
;
341 static int sh_msiof_spi_setup_transfer(struct spi_device
*spi
,
342 struct spi_transfer
*t
)
346 /* noting to check hz values against since parent clock is disabled */
348 bits
= sh_msiof_spi_bits(spi
, t
);
354 return spi_bitbang_setup_transfer(spi
, t
);
357 static void sh_msiof_spi_chipselect(struct spi_device
*spi
, int is_on
)
359 struct sh_msiof_spi_priv
*p
= spi_master_get_devdata(spi
->master
);
362 /* chip select is active low unless SPI_CS_HIGH is set */
363 if (spi
->mode
& SPI_CS_HIGH
)
364 value
= (is_on
== BITBANG_CS_ACTIVE
) ? 1 : 0;
366 value
= (is_on
== BITBANG_CS_ACTIVE
) ? 0 : 1;
368 if (is_on
== BITBANG_CS_ACTIVE
) {
369 if (!test_and_set_bit(0, &p
->flags
)) {
370 pm_runtime_get_sync(&p
->pdev
->dev
);
374 /* Configure pins before asserting CS */
375 sh_msiof_spi_set_pin_regs(p
, !!(spi
->mode
& SPI_CPOL
),
376 !!(spi
->mode
& SPI_CPHA
),
377 !!(spi
->mode
& SPI_3WIRE
),
378 !!(spi
->mode
& SPI_LSB_FIRST
));
381 /* use spi->controller data for CS (same strategy as spi_gpio) */
382 gpio_set_value((unsigned)spi
->controller_data
, value
);
384 if (is_on
== BITBANG_CS_INACTIVE
) {
385 if (test_and_clear_bit(0, &p
->flags
)) {
387 pm_runtime_put(&p
->pdev
->dev
);
392 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv
*p
,
393 void (*tx_fifo
)(struct sh_msiof_spi_priv
*,
394 const void *, int, int),
395 void (*rx_fifo
)(struct sh_msiof_spi_priv
*,
397 const void *tx_buf
, void *rx_buf
,
403 /* limit maximum word transfer to rx/tx fifo size */
405 words
= min_t(int, words
, p
->tx_fifo_size
);
407 words
= min_t(int, words
, p
->rx_fifo_size
);
409 /* the fifo contents need shifting */
410 fifo_shift
= 32 - bits
;
412 /* setup msiof transfer mode registers */
413 sh_msiof_spi_set_mode_regs(p
, tx_buf
, rx_buf
, bits
, words
);
417 tx_fifo(p
, tx_buf
, words
, fifo_shift
);
419 /* setup clock and rx/tx signals */
420 ret
= sh_msiof_modify_ctr_wait(p
, 0, CTR_TSCKE
);
422 ret
= ret
? ret
: sh_msiof_modify_ctr_wait(p
, 0, CTR_RXE
);
423 ret
= ret
? ret
: sh_msiof_modify_ctr_wait(p
, 0, CTR_TXE
);
425 /* start by setting frame bit */
426 INIT_COMPLETION(p
->done
);
427 ret
= ret
? ret
: sh_msiof_modify_ctr_wait(p
, 0, CTR_TFSE
);
429 dev_err(&p
->pdev
->dev
, "failed to start hardware\n");
433 /* wait for tx fifo to be emptied / rx fifo to be filled */
434 wait_for_completion(&p
->done
);
438 rx_fifo(p
, rx_buf
, words
, fifo_shift
);
440 /* clear status bits */
441 sh_msiof_reset_str(p
);
443 /* shut down frame, tx/tx and clock signals */
444 ret
= sh_msiof_modify_ctr_wait(p
, CTR_TFSE
, 0);
445 ret
= ret
? ret
: sh_msiof_modify_ctr_wait(p
, CTR_TXE
, 0);
447 ret
= ret
? ret
: sh_msiof_modify_ctr_wait(p
, CTR_RXE
, 0);
448 ret
= ret
? ret
: sh_msiof_modify_ctr_wait(p
, CTR_TSCKE
, 0);
450 dev_err(&p
->pdev
->dev
, "failed to shut down hardware\n");
457 sh_msiof_write(p
, IER
, 0);
461 static int sh_msiof_spi_txrx(struct spi_device
*spi
, struct spi_transfer
*t
)
463 struct sh_msiof_spi_priv
*p
= spi_master_get_devdata(spi
->master
);
464 void (*tx_fifo
)(struct sh_msiof_spi_priv
*, const void *, int, int);
465 void (*rx_fifo
)(struct sh_msiof_spi_priv
*, void *, int, int);
472 bits
= sh_msiof_spi_bits(spi
, t
);
474 /* setup bytes per word and fifo read/write functions */
477 tx_fifo
= sh_msiof_spi_write_fifo_8
;
478 rx_fifo
= sh_msiof_spi_read_fifo_8
;
479 } else if (bits
<= 16) {
481 if ((unsigned long)t
->tx_buf
& 0x01)
482 tx_fifo
= sh_msiof_spi_write_fifo_16u
;
484 tx_fifo
= sh_msiof_spi_write_fifo_16
;
486 if ((unsigned long)t
->rx_buf
& 0x01)
487 rx_fifo
= sh_msiof_spi_read_fifo_16u
;
489 rx_fifo
= sh_msiof_spi_read_fifo_16
;
492 if ((unsigned long)t
->tx_buf
& 0x03)
493 tx_fifo
= sh_msiof_spi_write_fifo_32u
;
495 tx_fifo
= sh_msiof_spi_write_fifo_32
;
497 if ((unsigned long)t
->rx_buf
& 0x03)
498 rx_fifo
= sh_msiof_spi_read_fifo_32u
;
500 rx_fifo
= sh_msiof_spi_read_fifo_32
;
503 /* setup clocks (clock already enabled in chipselect()) */
504 sh_msiof_spi_set_clk_regs(p
, clk_get_rate(p
->clk
),
505 sh_msiof_spi_hz(spi
, t
));
507 /* transfer in fifo sized chunks */
508 words
= t
->len
/ bytes_per_word
;
511 while (bytes_done
< t
->len
) {
512 void *rx_buf
= t
->rx_buf
? t
->rx_buf
+ bytes_done
: NULL
;
513 const void *tx_buf
= t
->tx_buf
? t
->tx_buf
+ bytes_done
: NULL
;
514 n
= sh_msiof_spi_txrx_once(p
, tx_fifo
, rx_fifo
,
521 bytes_done
+= n
* bytes_per_word
;
528 static u32
sh_msiof_spi_txrx_word(struct spi_device
*spi
, unsigned nsecs
,
531 BUG(); /* unused but needed by bitbang code */
535 static int sh_msiof_spi_probe(struct platform_device
*pdev
)
538 struct spi_master
*master
;
539 struct sh_msiof_spi_priv
*p
;
544 master
= spi_alloc_master(&pdev
->dev
, sizeof(struct sh_msiof_spi_priv
));
545 if (master
== NULL
) {
546 dev_err(&pdev
->dev
, "failed to allocate spi master\n");
551 p
= spi_master_get_devdata(master
);
553 platform_set_drvdata(pdev
, p
);
554 p
->info
= pdev
->dev
.platform_data
;
555 init_completion(&p
->done
);
557 snprintf(clk_name
, sizeof(clk_name
), "msiof%d", pdev
->id
);
558 p
->clk
= clk_get(&pdev
->dev
, clk_name
);
559 if (IS_ERR(p
->clk
)) {
560 dev_err(&pdev
->dev
, "cannot get clock \"%s\"\n", clk_name
);
561 ret
= PTR_ERR(p
->clk
);
565 r
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
566 i
= platform_get_irq(pdev
, 0);
568 dev_err(&pdev
->dev
, "cannot get platform resources\n");
572 p
->mapbase
= ioremap_nocache(r
->start
, resource_size(r
));
574 dev_err(&pdev
->dev
, "unable to ioremap\n");
579 ret
= request_irq(i
, sh_msiof_spi_irq
, IRQF_DISABLED
,
580 dev_name(&pdev
->dev
), p
);
582 dev_err(&pdev
->dev
, "unable to request irq\n");
587 pm_runtime_enable(&pdev
->dev
);
589 /* The standard version of MSIOF use 64 word FIFOs */
590 p
->tx_fifo_size
= 64;
591 p
->rx_fifo_size
= 64;
593 /* Platform data may override FIFO sizes */
594 if (p
->info
->tx_fifo_override
)
595 p
->tx_fifo_size
= p
->info
->tx_fifo_override
;
596 if (p
->info
->rx_fifo_override
)
597 p
->rx_fifo_size
= p
->info
->rx_fifo_override
;
599 /* init master and bitbang code */
600 master
->mode_bits
= SPI_CPOL
| SPI_CPHA
| SPI_CS_HIGH
;
601 master
->mode_bits
|= SPI_LSB_FIRST
| SPI_3WIRE
;
603 master
->bus_num
= pdev
->id
;
604 master
->num_chipselect
= p
->info
->num_chipselect
;
605 master
->setup
= spi_bitbang_setup
;
606 master
->cleanup
= spi_bitbang_cleanup
;
608 p
->bitbang
.master
= master
;
609 p
->bitbang
.chipselect
= sh_msiof_spi_chipselect
;
610 p
->bitbang
.setup_transfer
= sh_msiof_spi_setup_transfer
;
611 p
->bitbang
.txrx_bufs
= sh_msiof_spi_txrx
;
612 p
->bitbang
.txrx_word
[SPI_MODE_0
] = sh_msiof_spi_txrx_word
;
613 p
->bitbang
.txrx_word
[SPI_MODE_1
] = sh_msiof_spi_txrx_word
;
614 p
->bitbang
.txrx_word
[SPI_MODE_2
] = sh_msiof_spi_txrx_word
;
615 p
->bitbang
.txrx_word
[SPI_MODE_3
] = sh_msiof_spi_txrx_word
;
617 ret
= spi_bitbang_start(&p
->bitbang
);
621 pm_runtime_disable(&pdev
->dev
);
627 spi_master_put(master
);
632 static int sh_msiof_spi_remove(struct platform_device
*pdev
)
634 struct sh_msiof_spi_priv
*p
= platform_get_drvdata(pdev
);
637 ret
= spi_bitbang_stop(&p
->bitbang
);
639 pm_runtime_disable(&pdev
->dev
);
640 free_irq(platform_get_irq(pdev
, 0), p
);
643 spi_master_put(p
->bitbang
.master
);
648 static int sh_msiof_spi_runtime_nop(struct device
*dev
)
650 /* Runtime PM callback shared between ->runtime_suspend()
651 * and ->runtime_resume(). Simply returns success.
653 * This driver re-initializes all registers after
654 * pm_runtime_get_sync() anyway so there is no need
655 * to save and restore registers here.
660 static struct dev_pm_ops sh_msiof_spi_dev_pm_ops
= {
661 .runtime_suspend
= sh_msiof_spi_runtime_nop
,
662 .runtime_resume
= sh_msiof_spi_runtime_nop
,
665 static struct platform_driver sh_msiof_spi_drv
= {
666 .probe
= sh_msiof_spi_probe
,
667 .remove
= sh_msiof_spi_remove
,
669 .name
= "spi_sh_msiof",
670 .owner
= THIS_MODULE
,
671 .pm
= &sh_msiof_spi_dev_pm_ops
,
675 static int __init
sh_msiof_spi_init(void)
677 return platform_driver_register(&sh_msiof_spi_drv
);
679 module_init(sh_msiof_spi_init
);
681 static void __exit
sh_msiof_spi_exit(void)
683 platform_driver_unregister(&sh_msiof_spi_drv
);
685 module_exit(sh_msiof_spi_exit
);
687 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
688 MODULE_AUTHOR("Magnus Damm");
689 MODULE_LICENSE("GPL v2");
690 MODULE_ALIAS("platform:spi_sh_msiof");