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/bitmap.h>
13 #include <linux/clk.h>
14 #include <linux/completion.h>
15 #include <linux/delay.h>
16 #include <linux/err.h>
17 #include <linux/gpio.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
21 #include <linux/kernel.h>
22 #include <linux/platform_device.h>
23 #include <linux/pm_runtime.h>
25 #include <linux/spi/sh_msiof.h>
26 #include <linux/spi/spi.h>
27 #include <linux/spi/spi_bitbang.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 u32
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
,
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 u32 tx_hi_z
, u32 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 */
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
,
202 u32 dr2
= ((bits
- 1) << 24) | ((words
- 1) << 16);
205 sh_msiof_write(p
, TMDR2
, dr2
);
207 sh_msiof_write(p
, TMDR2
, dr2
| 1);
210 sh_msiof_write(p
, RMDR2
, dr2
);
212 sh_msiof_write(p
, IER
, STR_TEOF
| STR_REOF
);
215 static void sh_msiof_reset_str(struct sh_msiof_spi_priv
*p
)
217 sh_msiof_write(p
, STR
, sh_msiof_read(p
, STR
));
220 static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv
*p
,
221 const void *tx_buf
, int words
, int fs
)
223 const u8
*buf_8
= tx_buf
;
226 for (k
= 0; k
< words
; k
++)
227 sh_msiof_write(p
, TFDR
, buf_8
[k
] << fs
);
230 static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv
*p
,
231 const void *tx_buf
, int words
, int fs
)
233 const u16
*buf_16
= tx_buf
;
236 for (k
= 0; k
< words
; k
++)
237 sh_msiof_write(p
, TFDR
, buf_16
[k
] << fs
);
240 static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv
*p
,
241 const void *tx_buf
, int words
, int fs
)
243 const u16
*buf_16
= tx_buf
;
246 for (k
= 0; k
< words
; k
++)
247 sh_msiof_write(p
, TFDR
, get_unaligned(&buf_16
[k
]) << fs
);
250 static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv
*p
,
251 const void *tx_buf
, int words
, int fs
)
253 const u32
*buf_32
= tx_buf
;
256 for (k
= 0; k
< words
; k
++)
257 sh_msiof_write(p
, TFDR
, buf_32
[k
] << fs
);
260 static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv
*p
,
261 const void *tx_buf
, int words
, int fs
)
263 const u32
*buf_32
= tx_buf
;
266 for (k
= 0; k
< words
; k
++)
267 sh_msiof_write(p
, TFDR
, get_unaligned(&buf_32
[k
]) << fs
);
270 static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv
*p
,
271 const void *tx_buf
, int words
, int fs
)
273 const u32
*buf_32
= tx_buf
;
276 for (k
= 0; k
< words
; k
++)
277 sh_msiof_write(p
, TFDR
, swab32(buf_32
[k
] << fs
));
280 static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv
*p
,
281 const void *tx_buf
, int words
, int fs
)
283 const u32
*buf_32
= tx_buf
;
286 for (k
= 0; k
< words
; k
++)
287 sh_msiof_write(p
, TFDR
, swab32(get_unaligned(&buf_32
[k
]) << fs
));
290 static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv
*p
,
291 void *rx_buf
, int words
, int fs
)
296 for (k
= 0; k
< words
; k
++)
297 buf_8
[k
] = sh_msiof_read(p
, RFDR
) >> fs
;
300 static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv
*p
,
301 void *rx_buf
, int words
, int fs
)
303 u16
*buf_16
= rx_buf
;
306 for (k
= 0; k
< words
; k
++)
307 buf_16
[k
] = sh_msiof_read(p
, RFDR
) >> fs
;
310 static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv
*p
,
311 void *rx_buf
, int words
, int fs
)
313 u16
*buf_16
= rx_buf
;
316 for (k
= 0; k
< words
; k
++)
317 put_unaligned(sh_msiof_read(p
, RFDR
) >> fs
, &buf_16
[k
]);
320 static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv
*p
,
321 void *rx_buf
, int words
, int fs
)
323 u32
*buf_32
= rx_buf
;
326 for (k
= 0; k
< words
; k
++)
327 buf_32
[k
] = sh_msiof_read(p
, RFDR
) >> fs
;
330 static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv
*p
,
331 void *rx_buf
, int words
, int fs
)
333 u32
*buf_32
= rx_buf
;
336 for (k
= 0; k
< words
; k
++)
337 put_unaligned(sh_msiof_read(p
, RFDR
) >> fs
, &buf_32
[k
]);
340 static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv
*p
,
341 void *rx_buf
, int words
, int fs
)
343 u32
*buf_32
= rx_buf
;
346 for (k
= 0; k
< words
; k
++)
347 buf_32
[k
] = swab32(sh_msiof_read(p
, RFDR
) >> fs
);
350 static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv
*p
,
351 void *rx_buf
, int words
, int fs
)
353 u32
*buf_32
= rx_buf
;
356 for (k
= 0; k
< words
; k
++)
357 put_unaligned(swab32(sh_msiof_read(p
, RFDR
) >> fs
), &buf_32
[k
]);
360 static int sh_msiof_spi_bits(struct spi_device
*spi
, struct spi_transfer
*t
)
364 bits
= t
? t
->bits_per_word
: 0;
366 bits
= spi
->bits_per_word
;
370 static unsigned long sh_msiof_spi_hz(struct spi_device
*spi
,
371 struct spi_transfer
*t
)
375 hz
= t
? t
->speed_hz
: 0;
377 hz
= spi
->max_speed_hz
;
381 static int sh_msiof_spi_setup_transfer(struct spi_device
*spi
,
382 struct spi_transfer
*t
)
386 /* noting to check hz values against since parent clock is disabled */
388 bits
= sh_msiof_spi_bits(spi
, t
);
394 return spi_bitbang_setup_transfer(spi
, t
);
397 static void sh_msiof_spi_chipselect(struct spi_device
*spi
, int is_on
)
399 struct sh_msiof_spi_priv
*p
= spi_master_get_devdata(spi
->master
);
402 /* chip select is active low unless SPI_CS_HIGH is set */
403 if (spi
->mode
& SPI_CS_HIGH
)
404 value
= (is_on
== BITBANG_CS_ACTIVE
) ? 1 : 0;
406 value
= (is_on
== BITBANG_CS_ACTIVE
) ? 0 : 1;
408 if (is_on
== BITBANG_CS_ACTIVE
) {
409 if (!test_and_set_bit(0, &p
->flags
)) {
410 pm_runtime_get_sync(&p
->pdev
->dev
);
414 /* Configure pins before asserting CS */
415 sh_msiof_spi_set_pin_regs(p
, !!(spi
->mode
& SPI_CPOL
),
416 !!(spi
->mode
& SPI_CPHA
),
417 !!(spi
->mode
& SPI_3WIRE
),
418 !!(spi
->mode
& SPI_LSB_FIRST
));
421 /* use spi->controller data for CS (same strategy as spi_gpio) */
422 gpio_set_value((unsigned)spi
->controller_data
, value
);
424 if (is_on
== BITBANG_CS_INACTIVE
) {
425 if (test_and_clear_bit(0, &p
->flags
)) {
427 pm_runtime_put(&p
->pdev
->dev
);
432 static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv
*p
,
433 void (*tx_fifo
)(struct sh_msiof_spi_priv
*,
434 const void *, int, int),
435 void (*rx_fifo
)(struct sh_msiof_spi_priv
*,
437 const void *tx_buf
, void *rx_buf
,
443 /* limit maximum word transfer to rx/tx fifo size */
445 words
= min_t(int, words
, p
->tx_fifo_size
);
447 words
= min_t(int, words
, p
->rx_fifo_size
);
449 /* the fifo contents need shifting */
450 fifo_shift
= 32 - bits
;
452 /* setup msiof transfer mode registers */
453 sh_msiof_spi_set_mode_regs(p
, tx_buf
, rx_buf
, bits
, words
);
457 tx_fifo(p
, tx_buf
, words
, fifo_shift
);
459 /* setup clock and rx/tx signals */
460 ret
= sh_msiof_modify_ctr_wait(p
, 0, CTR_TSCKE
);
462 ret
= ret
? ret
: sh_msiof_modify_ctr_wait(p
, 0, CTR_RXE
);
463 ret
= ret
? ret
: sh_msiof_modify_ctr_wait(p
, 0, CTR_TXE
);
465 /* start by setting frame bit */
466 INIT_COMPLETION(p
->done
);
467 ret
= ret
? ret
: sh_msiof_modify_ctr_wait(p
, 0, CTR_TFSE
);
469 dev_err(&p
->pdev
->dev
, "failed to start hardware\n");
473 /* wait for tx fifo to be emptied / rx fifo to be filled */
474 wait_for_completion(&p
->done
);
478 rx_fifo(p
, rx_buf
, words
, fifo_shift
);
480 /* clear status bits */
481 sh_msiof_reset_str(p
);
483 /* shut down frame, tx/tx and clock signals */
484 ret
= sh_msiof_modify_ctr_wait(p
, CTR_TFSE
, 0);
485 ret
= ret
? ret
: sh_msiof_modify_ctr_wait(p
, CTR_TXE
, 0);
487 ret
= ret
? ret
: sh_msiof_modify_ctr_wait(p
, CTR_RXE
, 0);
488 ret
= ret
? ret
: sh_msiof_modify_ctr_wait(p
, CTR_TSCKE
, 0);
490 dev_err(&p
->pdev
->dev
, "failed to shut down hardware\n");
497 sh_msiof_write(p
, IER
, 0);
501 static int sh_msiof_spi_txrx(struct spi_device
*spi
, struct spi_transfer
*t
)
503 struct sh_msiof_spi_priv
*p
= spi_master_get_devdata(spi
->master
);
504 void (*tx_fifo
)(struct sh_msiof_spi_priv
*, const void *, int, int);
505 void (*rx_fifo
)(struct sh_msiof_spi_priv
*, void *, int, int);
513 bits
= sh_msiof_spi_bits(spi
, t
);
515 if (bits
<= 8 && t
->len
> 15 && !(t
->len
& 3)) {
522 /* setup bytes per word and fifo read/write functions */
525 tx_fifo
= sh_msiof_spi_write_fifo_8
;
526 rx_fifo
= sh_msiof_spi_read_fifo_8
;
527 } else if (bits
<= 16) {
529 if ((unsigned long)t
->tx_buf
& 0x01)
530 tx_fifo
= sh_msiof_spi_write_fifo_16u
;
532 tx_fifo
= sh_msiof_spi_write_fifo_16
;
534 if ((unsigned long)t
->rx_buf
& 0x01)
535 rx_fifo
= sh_msiof_spi_read_fifo_16u
;
537 rx_fifo
= sh_msiof_spi_read_fifo_16
;
540 if ((unsigned long)t
->tx_buf
& 0x03)
541 tx_fifo
= sh_msiof_spi_write_fifo_s32u
;
543 tx_fifo
= sh_msiof_spi_write_fifo_s32
;
545 if ((unsigned long)t
->rx_buf
& 0x03)
546 rx_fifo
= sh_msiof_spi_read_fifo_s32u
;
548 rx_fifo
= sh_msiof_spi_read_fifo_s32
;
551 if ((unsigned long)t
->tx_buf
& 0x03)
552 tx_fifo
= sh_msiof_spi_write_fifo_32u
;
554 tx_fifo
= sh_msiof_spi_write_fifo_32
;
556 if ((unsigned long)t
->rx_buf
& 0x03)
557 rx_fifo
= sh_msiof_spi_read_fifo_32u
;
559 rx_fifo
= sh_msiof_spi_read_fifo_32
;
562 /* setup clocks (clock already enabled in chipselect()) */
563 sh_msiof_spi_set_clk_regs(p
, clk_get_rate(p
->clk
),
564 sh_msiof_spi_hz(spi
, t
));
566 /* transfer in fifo sized chunks */
567 words
= t
->len
/ bytes_per_word
;
570 while (bytes_done
< t
->len
) {
571 void *rx_buf
= t
->rx_buf
? t
->rx_buf
+ bytes_done
: NULL
;
572 const void *tx_buf
= t
->tx_buf
? t
->tx_buf
+ bytes_done
: NULL
;
573 n
= sh_msiof_spi_txrx_once(p
, tx_fifo
, rx_fifo
,
580 bytes_done
+= n
* bytes_per_word
;
587 static u32
sh_msiof_spi_txrx_word(struct spi_device
*spi
, unsigned nsecs
,
590 BUG(); /* unused but needed by bitbang code */
594 static int sh_msiof_spi_probe(struct platform_device
*pdev
)
597 struct spi_master
*master
;
598 struct sh_msiof_spi_priv
*p
;
603 master
= spi_alloc_master(&pdev
->dev
, sizeof(struct sh_msiof_spi_priv
));
604 if (master
== NULL
) {
605 dev_err(&pdev
->dev
, "failed to allocate spi master\n");
610 p
= spi_master_get_devdata(master
);
612 platform_set_drvdata(pdev
, p
);
613 p
->info
= pdev
->dev
.platform_data
;
614 init_completion(&p
->done
);
616 snprintf(clk_name
, sizeof(clk_name
), "msiof%d", pdev
->id
);
617 p
->clk
= clk_get(&pdev
->dev
, clk_name
);
618 if (IS_ERR(p
->clk
)) {
619 dev_err(&pdev
->dev
, "cannot get clock \"%s\"\n", clk_name
);
620 ret
= PTR_ERR(p
->clk
);
624 r
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
625 i
= platform_get_irq(pdev
, 0);
627 dev_err(&pdev
->dev
, "cannot get platform resources\n");
631 p
->mapbase
= ioremap_nocache(r
->start
, resource_size(r
));
633 dev_err(&pdev
->dev
, "unable to ioremap\n");
638 ret
= request_irq(i
, sh_msiof_spi_irq
, IRQF_DISABLED
,
639 dev_name(&pdev
->dev
), p
);
641 dev_err(&pdev
->dev
, "unable to request irq\n");
646 pm_runtime_enable(&pdev
->dev
);
648 /* The standard version of MSIOF use 64 word FIFOs */
649 p
->tx_fifo_size
= 64;
650 p
->rx_fifo_size
= 64;
652 /* Platform data may override FIFO sizes */
653 if (p
->info
->tx_fifo_override
)
654 p
->tx_fifo_size
= p
->info
->tx_fifo_override
;
655 if (p
->info
->rx_fifo_override
)
656 p
->rx_fifo_size
= p
->info
->rx_fifo_override
;
658 /* init master and bitbang code */
659 master
->mode_bits
= SPI_CPOL
| SPI_CPHA
| SPI_CS_HIGH
;
660 master
->mode_bits
|= SPI_LSB_FIRST
| SPI_3WIRE
;
662 master
->bus_num
= pdev
->id
;
663 master
->num_chipselect
= p
->info
->num_chipselect
;
664 master
->setup
= spi_bitbang_setup
;
665 master
->cleanup
= spi_bitbang_cleanup
;
667 p
->bitbang
.master
= master
;
668 p
->bitbang
.chipselect
= sh_msiof_spi_chipselect
;
669 p
->bitbang
.setup_transfer
= sh_msiof_spi_setup_transfer
;
670 p
->bitbang
.txrx_bufs
= sh_msiof_spi_txrx
;
671 p
->bitbang
.txrx_word
[SPI_MODE_0
] = sh_msiof_spi_txrx_word
;
672 p
->bitbang
.txrx_word
[SPI_MODE_1
] = sh_msiof_spi_txrx_word
;
673 p
->bitbang
.txrx_word
[SPI_MODE_2
] = sh_msiof_spi_txrx_word
;
674 p
->bitbang
.txrx_word
[SPI_MODE_3
] = sh_msiof_spi_txrx_word
;
676 ret
= spi_bitbang_start(&p
->bitbang
);
680 pm_runtime_disable(&pdev
->dev
);
686 spi_master_put(master
);
691 static int sh_msiof_spi_remove(struct platform_device
*pdev
)
693 struct sh_msiof_spi_priv
*p
= platform_get_drvdata(pdev
);
696 ret
= spi_bitbang_stop(&p
->bitbang
);
698 pm_runtime_disable(&pdev
->dev
);
699 free_irq(platform_get_irq(pdev
, 0), p
);
702 spi_master_put(p
->bitbang
.master
);
707 static int sh_msiof_spi_runtime_nop(struct device
*dev
)
709 /* Runtime PM callback shared between ->runtime_suspend()
710 * and ->runtime_resume(). Simply returns success.
712 * This driver re-initializes all registers after
713 * pm_runtime_get_sync() anyway so there is no need
714 * to save and restore registers here.
719 static struct dev_pm_ops sh_msiof_spi_dev_pm_ops
= {
720 .runtime_suspend
= sh_msiof_spi_runtime_nop
,
721 .runtime_resume
= sh_msiof_spi_runtime_nop
,
724 static struct platform_driver sh_msiof_spi_drv
= {
725 .probe
= sh_msiof_spi_probe
,
726 .remove
= sh_msiof_spi_remove
,
728 .name
= "spi_sh_msiof",
729 .owner
= THIS_MODULE
,
730 .pm
= &sh_msiof_spi_dev_pm_ops
,
734 static int __init
sh_msiof_spi_init(void)
736 return platform_driver_register(&sh_msiof_spi_drv
);
738 module_init(sh_msiof_spi_init
);
740 static void __exit
sh_msiof_spi_exit(void)
742 platform_driver_unregister(&sh_msiof_spi_drv
);
744 module_exit(sh_msiof_spi_exit
);
746 MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
747 MODULE_AUTHOR("Magnus Damm");
748 MODULE_LICENSE("GPL v2");
749 MODULE_ALIAS("platform:spi_sh_msiof");