1 // SPDX-License-Identifier: GPL-2.0
3 * bcm2835 sdhost driver.
5 * The 2835 has two SD controllers: The Arasan sdhci controller
6 * (supported by the iproc driver) and a custom sdhost controller
7 * (supported by this driver).
9 * The sdhci controller supports both sdcard and sdio. The sdhost
10 * controller supports the sdcard only, but has better performance.
11 * Also note that the rpi3 has sdio wifi, so driving the sdcard with
12 * the sdhost controller allows to use the sdhci controller for wifi
15 * The configuration is done by devicetree via pin muxing. Both
16 * SD controller are available on the same pins (2 pin groups = pin 22
17 * to 27 + pin 48 to 53). So it's possible to use both SD controllers
18 * at the same time with different pin groups.
20 * Author: Phil Elwell <phil@raspberrypi.org>
21 * Copyright (C) 2015-2016 Raspberry Pi (Trading) Ltd.
24 * mmc-bcm2835.c by Gellert Weisz
25 * which is, in turn, based on
26 * sdhci-bcm2708.c by Broadcom
27 * sdhci-bcm2835.c by Stephen Warren and Oleksandr Tymoshenko
28 * sdhci.c and sdhci-pci.c by Pierre Ossman
30 #include <linux/clk.h>
31 #include <linux/delay.h>
32 #include <linux/device.h>
33 #include <linux/dmaengine.h>
34 #include <linux/dma-mapping.h>
35 #include <linux/err.h>
36 #include <linux/highmem.h>
37 #include <linux/interrupt.h>
39 #include <linux/iopoll.h>
40 #include <linux/module.h>
41 #include <linux/of_address.h>
42 #include <linux/of_irq.h>
43 #include <linux/platform_device.h>
44 #include <linux/scatterlist.h>
45 #include <linux/time.h>
46 #include <linux/workqueue.h>
48 #include <linux/mmc/host.h>
49 #include <linux/mmc/mmc.h>
50 #include <linux/mmc/sd.h>
52 #define SDCMD 0x00 /* Command to SD card - 16 R/W */
53 #define SDARG 0x04 /* Argument to SD card - 32 R/W */
54 #define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */
55 #define SDCDIV 0x0c /* Start value for clock divider - 11 R/W */
56 #define SDRSP0 0x10 /* SD card response (31:0) - 32 R */
57 #define SDRSP1 0x14 /* SD card response (63:32) - 32 R */
58 #define SDRSP2 0x18 /* SD card response (95:64) - 32 R */
59 #define SDRSP3 0x1c /* SD card response (127:96) - 32 R */
60 #define SDHSTS 0x20 /* SD host status - 11 R/W */
61 #define SDVDD 0x30 /* SD card power control - 1 R/W */
62 #define SDEDM 0x34 /* Emergency Debug Mode - 13 R/W */
63 #define SDHCFG 0x38 /* Host configuration - 2 R/W */
64 #define SDHBCT 0x3c /* Host byte count (debug) - 32 R/W */
65 #define SDDATA 0x40 /* Data to/from SD card - 32 R/W */
66 #define SDHBLC 0x50 /* Host block count (SDIO/SDHC) - 9 R/W */
68 #define SDCMD_NEW_FLAG 0x8000
69 #define SDCMD_FAIL_FLAG 0x4000
70 #define SDCMD_BUSYWAIT 0x800
71 #define SDCMD_NO_RESPONSE 0x400
72 #define SDCMD_LONG_RESPONSE 0x200
73 #define SDCMD_WRITE_CMD 0x80
74 #define SDCMD_READ_CMD 0x40
75 #define SDCMD_CMD_MASK 0x3f
77 #define SDCDIV_MAX_CDIV 0x7ff
79 #define SDHSTS_BUSY_IRPT 0x400
80 #define SDHSTS_BLOCK_IRPT 0x200
81 #define SDHSTS_SDIO_IRPT 0x100
82 #define SDHSTS_REW_TIME_OUT 0x80
83 #define SDHSTS_CMD_TIME_OUT 0x40
84 #define SDHSTS_CRC16_ERROR 0x20
85 #define SDHSTS_CRC7_ERROR 0x10
86 #define SDHSTS_FIFO_ERROR 0x08
89 #define SDHSTS_DATA_FLAG 0x01
91 #define SDHSTS_TRANSFER_ERROR_MASK (SDHSTS_CRC7_ERROR | \
92 SDHSTS_CRC16_ERROR | \
93 SDHSTS_REW_TIME_OUT | \
96 #define SDHSTS_ERROR_MASK (SDHSTS_CMD_TIME_OUT | \
97 SDHSTS_TRANSFER_ERROR_MASK)
99 #define SDHCFG_BUSY_IRPT_EN BIT(10)
100 #define SDHCFG_BLOCK_IRPT_EN BIT(8)
101 #define SDHCFG_SDIO_IRPT_EN BIT(5)
102 #define SDHCFG_DATA_IRPT_EN BIT(4)
103 #define SDHCFG_SLOW_CARD BIT(3)
104 #define SDHCFG_WIDE_EXT_BUS BIT(2)
105 #define SDHCFG_WIDE_INT_BUS BIT(1)
106 #define SDHCFG_REL_CMD_LINE BIT(0)
108 #define SDVDD_POWER_OFF 0
109 #define SDVDD_POWER_ON 1
111 #define SDEDM_FORCE_DATA_MODE BIT(19)
112 #define SDEDM_CLOCK_PULSE BIT(20)
113 #define SDEDM_BYPASS BIT(21)
115 #define SDEDM_WRITE_THRESHOLD_SHIFT 9
116 #define SDEDM_READ_THRESHOLD_SHIFT 14
117 #define SDEDM_THRESHOLD_MASK 0x1f
119 #define SDEDM_FSM_MASK 0xf
120 #define SDEDM_FSM_IDENTMODE 0x0
121 #define SDEDM_FSM_DATAMODE 0x1
122 #define SDEDM_FSM_READDATA 0x2
123 #define SDEDM_FSM_WRITEDATA 0x3
124 #define SDEDM_FSM_READWAIT 0x4
125 #define SDEDM_FSM_READCRC 0x5
126 #define SDEDM_FSM_WRITECRC 0x6
127 #define SDEDM_FSM_WRITEWAIT1 0x7
128 #define SDEDM_FSM_POWERDOWN 0x8
129 #define SDEDM_FSM_POWERUP 0x9
130 #define SDEDM_FSM_WRITESTART1 0xa
131 #define SDEDM_FSM_WRITESTART2 0xb
132 #define SDEDM_FSM_GENPULSES 0xc
133 #define SDEDM_FSM_WRITEWAIT2 0xd
134 #define SDEDM_FSM_STARTPOWDOWN 0xf
136 #define SDDATA_FIFO_WORDS 16
138 #define FIFO_READ_THRESHOLD 4
139 #define FIFO_WRITE_THRESHOLD 4
140 #define SDDATA_FIFO_PIO_BURST 8
142 #define PIO_THRESHOLD 1 /* Maximum block count for PIO (0 = always DMA) */
144 struct bcm2835_host
{
148 void __iomem
*ioaddr
;
151 struct platform_device
*pdev
;
153 int clock
; /* Current clock speed */
154 unsigned int max_clk
; /* Max possible freq */
155 struct work_struct dma_work
;
156 struct delayed_work timeout_work
; /* Timer for timeouts */
157 struct sg_mapping_iter sg_miter
; /* SG state for PIO */
158 unsigned int blocks
; /* remaining PIO blocks */
159 int irq
; /* Device IRQ */
161 u32 ns_per_fifo_word
;
163 /* cached registers */
167 struct mmc_request
*mrq
; /* Current request */
168 struct mmc_command
*cmd
; /* Current command */
169 struct mmc_data
*data
; /* Current data request */
170 bool data_complete
:1;/* Data finished before cmd */
171 bool use_busy
:1; /* Wait for busy interrupt */
172 bool use_sbc
:1; /* Send CMD23 */
174 /* for threaded irq handler */
180 struct dma_chan
*dma_chan_rxtx
;
181 struct dma_chan
*dma_chan
;
182 struct dma_slave_config dma_cfg_rx
;
183 struct dma_slave_config dma_cfg_tx
;
184 struct dma_async_tx_descriptor
*dma_desc
;
187 struct page
*drain_page
;
192 static void bcm2835_dumpcmd(struct bcm2835_host
*host
, struct mmc_command
*cmd
,
195 struct device
*dev
= &host
->pdev
->dev
;
200 dev_dbg(dev
, "%c%s op %d arg 0x%x flags 0x%x - resp %08x %08x %08x %08x, err %d\n",
201 (cmd
== host
->cmd
) ? '>' : ' ',
202 label
, cmd
->opcode
, cmd
->arg
, cmd
->flags
,
203 cmd
->resp
[0], cmd
->resp
[1], cmd
->resp
[2], cmd
->resp
[3],
207 static void bcm2835_dumpregs(struct bcm2835_host
*host
)
209 struct mmc_request
*mrq
= host
->mrq
;
210 struct device
*dev
= &host
->pdev
->dev
;
213 bcm2835_dumpcmd(host
, mrq
->sbc
, "sbc");
214 bcm2835_dumpcmd(host
, mrq
->cmd
, "cmd");
216 dev_dbg(dev
, "data blocks %x blksz %x - err %d\n",
221 bcm2835_dumpcmd(host
, mrq
->stop
, "stop");
224 dev_dbg(dev
, "=========== REGISTER DUMP ===========\n");
225 dev_dbg(dev
, "SDCMD 0x%08x\n", readl(host
->ioaddr
+ SDCMD
));
226 dev_dbg(dev
, "SDARG 0x%08x\n", readl(host
->ioaddr
+ SDARG
));
227 dev_dbg(dev
, "SDTOUT 0x%08x\n", readl(host
->ioaddr
+ SDTOUT
));
228 dev_dbg(dev
, "SDCDIV 0x%08x\n", readl(host
->ioaddr
+ SDCDIV
));
229 dev_dbg(dev
, "SDRSP0 0x%08x\n", readl(host
->ioaddr
+ SDRSP0
));
230 dev_dbg(dev
, "SDRSP1 0x%08x\n", readl(host
->ioaddr
+ SDRSP1
));
231 dev_dbg(dev
, "SDRSP2 0x%08x\n", readl(host
->ioaddr
+ SDRSP2
));
232 dev_dbg(dev
, "SDRSP3 0x%08x\n", readl(host
->ioaddr
+ SDRSP3
));
233 dev_dbg(dev
, "SDHSTS 0x%08x\n", readl(host
->ioaddr
+ SDHSTS
));
234 dev_dbg(dev
, "SDVDD 0x%08x\n", readl(host
->ioaddr
+ SDVDD
));
235 dev_dbg(dev
, "SDEDM 0x%08x\n", readl(host
->ioaddr
+ SDEDM
));
236 dev_dbg(dev
, "SDHCFG 0x%08x\n", readl(host
->ioaddr
+ SDHCFG
));
237 dev_dbg(dev
, "SDHBCT 0x%08x\n", readl(host
->ioaddr
+ SDHBCT
));
238 dev_dbg(dev
, "SDHBLC 0x%08x\n", readl(host
->ioaddr
+ SDHBLC
));
239 dev_dbg(dev
, "===========================================\n");
242 static void bcm2835_reset_internal(struct bcm2835_host
*host
)
246 writel(SDVDD_POWER_OFF
, host
->ioaddr
+ SDVDD
);
247 writel(0, host
->ioaddr
+ SDCMD
);
248 writel(0, host
->ioaddr
+ SDARG
);
249 writel(0xf00000, host
->ioaddr
+ SDTOUT
);
250 writel(0, host
->ioaddr
+ SDCDIV
);
251 writel(0x7f8, host
->ioaddr
+ SDHSTS
); /* Write 1s to clear */
252 writel(0, host
->ioaddr
+ SDHCFG
);
253 writel(0, host
->ioaddr
+ SDHBCT
);
254 writel(0, host
->ioaddr
+ SDHBLC
);
256 /* Limit fifo usage due to silicon bug */
257 temp
= readl(host
->ioaddr
+ SDEDM
);
258 temp
&= ~((SDEDM_THRESHOLD_MASK
<< SDEDM_READ_THRESHOLD_SHIFT
) |
259 (SDEDM_THRESHOLD_MASK
<< SDEDM_WRITE_THRESHOLD_SHIFT
));
260 temp
|= (FIFO_READ_THRESHOLD
<< SDEDM_READ_THRESHOLD_SHIFT
) |
261 (FIFO_WRITE_THRESHOLD
<< SDEDM_WRITE_THRESHOLD_SHIFT
);
262 writel(temp
, host
->ioaddr
+ SDEDM
);
264 writel(SDVDD_POWER_ON
, host
->ioaddr
+ SDVDD
);
267 writel(host
->hcfg
, host
->ioaddr
+ SDHCFG
);
268 writel(host
->cdiv
, host
->ioaddr
+ SDCDIV
);
271 static void bcm2835_reset(struct mmc_host
*mmc
)
273 struct bcm2835_host
*host
= mmc_priv(mmc
);
276 dmaengine_terminate_sync(host
->dma_chan
);
277 host
->dma_chan
= NULL
;
278 bcm2835_reset_internal(host
);
281 static void bcm2835_finish_command(struct bcm2835_host
*host
);
283 static void bcm2835_wait_transfer_complete(struct bcm2835_host
*host
)
288 alternate_idle
= (host
->mrq
->data
->flags
& MMC_DATA_READ
) ?
289 SDEDM_FSM_READWAIT
: SDEDM_FSM_WRITESTART1
;
296 edm
= readl(host
->ioaddr
+ SDEDM
);
297 fsm
= edm
& SDEDM_FSM_MASK
;
299 if ((fsm
== SDEDM_FSM_IDENTMODE
) ||
300 (fsm
== SDEDM_FSM_DATAMODE
))
302 if (fsm
== alternate_idle
) {
303 writel(edm
| SDEDM_FORCE_DATA_MODE
,
304 host
->ioaddr
+ SDEDM
);
309 if (timediff
== 100000) {
310 dev_err(&host
->pdev
->dev
,
311 "wait_transfer_complete - still waiting after %d retries\n",
313 bcm2835_dumpregs(host
);
314 host
->mrq
->data
->error
= -ETIMEDOUT
;
321 static void bcm2835_dma_complete(void *param
)
323 struct bcm2835_host
*host
= param
;
325 schedule_work(&host
->dma_work
);
328 static void bcm2835_transfer_block_pio(struct bcm2835_host
*host
, bool is_read
)
332 unsigned long wait_max
;
334 blksize
= host
->data
->blksz
;
336 wait_max
= jiffies
+ msecs_to_jiffies(500);
338 local_irq_save(flags
);
346 if (!sg_miter_next(&host
->sg_miter
)) {
347 host
->data
->error
= -EINVAL
;
351 len
= min(host
->sg_miter
.length
, blksize
);
353 host
->data
->error
= -EINVAL
;
358 host
->sg_miter
.consumed
= len
;
360 buf
= (u32
*)host
->sg_miter
.addr
;
362 copy_words
= len
/ 4;
365 int burst_words
, words
;
368 burst_words
= min(SDDATA_FIFO_PIO_BURST
, copy_words
);
369 edm
= readl(host
->ioaddr
+ SDEDM
);
371 words
= ((edm
>> 4) & 0x1f);
373 words
= SDDATA_FIFO_WORDS
- ((edm
>> 4) & 0x1f);
375 if (words
< burst_words
) {
376 int fsm_state
= (edm
& SDEDM_FSM_MASK
);
377 struct device
*dev
= &host
->pdev
->dev
;
380 (fsm_state
!= SDEDM_FSM_READDATA
&&
381 fsm_state
!= SDEDM_FSM_READWAIT
&&
382 fsm_state
!= SDEDM_FSM_READCRC
)) ||
384 (fsm_state
!= SDEDM_FSM_WRITEDATA
&&
385 fsm_state
!= SDEDM_FSM_WRITESTART1
&&
386 fsm_state
!= SDEDM_FSM_WRITESTART2
))) {
387 hsts
= readl(host
->ioaddr
+ SDHSTS
);
388 dev_err(dev
, "fsm %x, hsts %08x\n",
390 if (hsts
& SDHSTS_ERROR_MASK
)
394 if (time_after(jiffies
, wait_max
)) {
395 dev_err(dev
, "PIO %s timeout - EDM %08x\n",
396 is_read
? "read" : "write",
398 hsts
= SDHSTS_REW_TIME_OUT
;
401 ndelay((burst_words
- words
) *
402 host
->ns_per_fifo_word
);
404 } else if (words
> copy_words
) {
412 *(buf
++) = readl(host
->ioaddr
+ SDDATA
);
414 writel(*(buf
++), host
->ioaddr
+ SDDATA
);
419 if (hsts
& SDHSTS_ERROR_MASK
)
423 sg_miter_stop(&host
->sg_miter
);
425 local_irq_restore(flags
);
428 static void bcm2835_transfer_pio(struct bcm2835_host
*host
)
430 struct device
*dev
= &host
->pdev
->dev
;
434 is_read
= (host
->data
->flags
& MMC_DATA_READ
) != 0;
435 bcm2835_transfer_block_pio(host
, is_read
);
437 sdhsts
= readl(host
->ioaddr
+ SDHSTS
);
438 if (sdhsts
& (SDHSTS_CRC16_ERROR
|
440 SDHSTS_FIFO_ERROR
)) {
441 dev_err(dev
, "%s transfer error - HSTS %08x\n",
442 is_read
? "read" : "write", sdhsts
);
443 host
->data
->error
= -EILSEQ
;
444 } else if ((sdhsts
& (SDHSTS_CMD_TIME_OUT
|
445 SDHSTS_REW_TIME_OUT
))) {
446 dev_err(dev
, "%s timeout error - HSTS %08x\n",
447 is_read
? "read" : "write", sdhsts
);
448 host
->data
->error
= -ETIMEDOUT
;
453 void bcm2835_prepare_dma(struct bcm2835_host
*host
, struct mmc_data
*data
)
455 int sg_len
, dir_data
, dir_slave
;
456 struct dma_async_tx_descriptor
*desc
= NULL
;
457 struct dma_chan
*dma_chan
;
459 dma_chan
= host
->dma_chan_rxtx
;
460 if (data
->flags
& MMC_DATA_READ
) {
461 dir_data
= DMA_FROM_DEVICE
;
462 dir_slave
= DMA_DEV_TO_MEM
;
464 dir_data
= DMA_TO_DEVICE
;
465 dir_slave
= DMA_MEM_TO_DEV
;
468 /* The block doesn't manage the FIFO DREQs properly for
469 * multi-block transfers, so don't attempt to DMA the final
470 * few words. Unfortunately this requires the final sg entry
471 * to be trimmed. N.B. This code demands that the overspill
472 * is contained in a single sg entry.
475 host
->drain_words
= 0;
476 if ((data
->blocks
> 1) && (dir_data
== DMA_FROM_DEVICE
)) {
477 struct scatterlist
*sg
;
481 len
= min((u32
)(FIFO_READ_THRESHOLD
- 1) * 4,
482 (u32
)data
->blocks
* data
->blksz
);
484 for_each_sg(data
->sg
, sg
, data
->sg_len
, i
) {
485 if (sg_is_last(sg
)) {
486 WARN_ON(sg
->length
< len
);
488 host
->drain_page
= sg_page(sg
);
489 host
->drain_offset
= sg
->offset
+ sg
->length
;
492 host
->drain_words
= len
/ 4;
495 /* The parameters have already been validated, so this will not fail */
496 (void)dmaengine_slave_config(dma_chan
,
497 (dir_data
== DMA_FROM_DEVICE
) ?
501 sg_len
= dma_map_sg(dma_chan
->device
->dev
, data
->sg
, data
->sg_len
,
506 desc
= dmaengine_prep_slave_sg(dma_chan
, data
->sg
, sg_len
, dir_slave
,
507 DMA_PREP_INTERRUPT
| DMA_CTRL_ACK
);
510 dma_unmap_sg(dma_chan
->device
->dev
, data
->sg
, sg_len
, dir_data
);
514 desc
->callback
= bcm2835_dma_complete
;
515 desc
->callback_param
= host
;
516 host
->dma_desc
= desc
;
517 host
->dma_chan
= dma_chan
;
518 host
->dma_dir
= dir_data
;
521 static void bcm2835_start_dma(struct bcm2835_host
*host
)
523 dmaengine_submit(host
->dma_desc
);
524 dma_async_issue_pending(host
->dma_chan
);
527 static void bcm2835_set_transfer_irqs(struct bcm2835_host
*host
)
529 u32 all_irqs
= SDHCFG_DATA_IRPT_EN
| SDHCFG_BLOCK_IRPT_EN
|
532 if (host
->dma_desc
) {
533 host
->hcfg
= (host
->hcfg
& ~all_irqs
) |
536 host
->hcfg
= (host
->hcfg
& ~all_irqs
) |
537 SDHCFG_DATA_IRPT_EN
|
541 writel(host
->hcfg
, host
->ioaddr
+ SDHCFG
);
545 void bcm2835_prepare_data(struct bcm2835_host
*host
, struct mmc_command
*cmd
)
547 struct mmc_data
*data
= cmd
->data
;
555 host
->data_complete
= false;
556 host
->data
->bytes_xfered
= 0;
558 if (!host
->dma_desc
) {
560 int flags
= SG_MITER_ATOMIC
;
562 if (data
->flags
& MMC_DATA_READ
)
563 flags
|= SG_MITER_TO_SG
;
565 flags
|= SG_MITER_FROM_SG
;
566 sg_miter_start(&host
->sg_miter
, data
->sg
, data
->sg_len
, flags
);
567 host
->blocks
= data
->blocks
;
570 bcm2835_set_transfer_irqs(host
);
572 writel(data
->blksz
, host
->ioaddr
+ SDHBCT
);
573 writel(data
->blocks
, host
->ioaddr
+ SDHBLC
);
576 static u32
bcm2835_read_wait_sdcmd(struct bcm2835_host
*host
, u32 max_ms
)
578 struct device
*dev
= &host
->pdev
->dev
;
582 ret
= readl_poll_timeout(host
->ioaddr
+ SDCMD
, value
,
583 !(value
& SDCMD_NEW_FLAG
), 1, 10);
584 if (ret
== -ETIMEDOUT
)
585 /* if it takes a while make poll interval bigger */
586 ret
= readl_poll_timeout(host
->ioaddr
+ SDCMD
, value
,
587 !(value
& SDCMD_NEW_FLAG
),
589 if (ret
== -ETIMEDOUT
)
590 dev_err(dev
, "%s: timeout (%d ms)\n", __func__
, max_ms
);
595 static void bcm2835_finish_request(struct bcm2835_host
*host
)
597 struct dma_chan
*terminate_chan
= NULL
;
598 struct mmc_request
*mrq
;
600 cancel_delayed_work(&host
->timeout_work
);
608 host
->dma_desc
= NULL
;
609 terminate_chan
= host
->dma_chan
;
610 host
->dma_chan
= NULL
;
612 if (terminate_chan
) {
613 int err
= dmaengine_terminate_all(terminate_chan
);
616 dev_err(&host
->pdev
->dev
,
617 "failed to terminate DMA (%d)\n", err
);
620 mmc_request_done(mmc_from_priv(host
), mrq
);
624 bool bcm2835_send_command(struct bcm2835_host
*host
, struct mmc_command
*cmd
)
626 struct device
*dev
= &host
->pdev
->dev
;
628 unsigned long timeout
;
632 sdcmd
= bcm2835_read_wait_sdcmd(host
, 100);
633 if (sdcmd
& SDCMD_NEW_FLAG
) {
634 dev_err(dev
, "previous command never completed.\n");
635 bcm2835_dumpregs(host
);
636 cmd
->error
= -EILSEQ
;
637 bcm2835_finish_request(host
);
641 if (!cmd
->data
&& cmd
->busy_timeout
> 9000)
642 timeout
= DIV_ROUND_UP(cmd
->busy_timeout
, 1000) * HZ
+ HZ
;
645 schedule_delayed_work(&host
->timeout_work
, timeout
);
649 /* Clear any error flags */
650 sdhsts
= readl(host
->ioaddr
+ SDHSTS
);
651 if (sdhsts
& SDHSTS_ERROR_MASK
)
652 writel(sdhsts
, host
->ioaddr
+ SDHSTS
);
654 if ((cmd
->flags
& MMC_RSP_136
) && (cmd
->flags
& MMC_RSP_BUSY
)) {
655 dev_err(dev
, "unsupported response type!\n");
656 cmd
->error
= -EINVAL
;
657 bcm2835_finish_request(host
);
661 bcm2835_prepare_data(host
, cmd
);
663 writel(cmd
->arg
, host
->ioaddr
+ SDARG
);
665 sdcmd
= cmd
->opcode
& SDCMD_CMD_MASK
;
667 host
->use_busy
= false;
668 if (!(cmd
->flags
& MMC_RSP_PRESENT
)) {
669 sdcmd
|= SDCMD_NO_RESPONSE
;
671 if (cmd
->flags
& MMC_RSP_136
)
672 sdcmd
|= SDCMD_LONG_RESPONSE
;
673 if (cmd
->flags
& MMC_RSP_BUSY
) {
674 sdcmd
|= SDCMD_BUSYWAIT
;
675 host
->use_busy
= true;
680 if (cmd
->data
->flags
& MMC_DATA_WRITE
)
681 sdcmd
|= SDCMD_WRITE_CMD
;
682 if (cmd
->data
->flags
& MMC_DATA_READ
)
683 sdcmd
|= SDCMD_READ_CMD
;
686 writel(sdcmd
| SDCMD_NEW_FLAG
, host
->ioaddr
+ SDCMD
);
691 static void bcm2835_transfer_complete(struct bcm2835_host
*host
)
693 struct mmc_data
*data
;
695 WARN_ON(!host
->data_complete
);
700 /* Need to send CMD12 if -
701 * a) open-ended multiblock transfer (no CMD23)
702 * b) error in multiblock transfer
704 if (host
->mrq
->stop
&& (data
->error
|| !host
->use_sbc
)) {
705 if (bcm2835_send_command(host
, host
->mrq
->stop
)) {
706 /* No busy, so poll for completion */
708 bcm2835_finish_command(host
);
711 bcm2835_wait_transfer_complete(host
);
712 bcm2835_finish_request(host
);
716 static void bcm2835_finish_data(struct bcm2835_host
*host
)
718 struct device
*dev
= &host
->pdev
->dev
;
719 struct mmc_data
*data
;
723 host
->hcfg
&= ~(SDHCFG_DATA_IRPT_EN
| SDHCFG_BLOCK_IRPT_EN
);
724 writel(host
->hcfg
, host
->ioaddr
+ SDHCFG
);
726 data
->bytes_xfered
= data
->error
? 0 : (data
->blksz
* data
->blocks
);
728 host
->data_complete
= true;
731 /* Data managed to finish before the
732 * command completed. Make sure we do
733 * things in the proper order.
735 dev_dbg(dev
, "Finished early - HSTS %08x\n",
736 readl(host
->ioaddr
+ SDHSTS
));
738 bcm2835_transfer_complete(host
);
742 static void bcm2835_finish_command(struct bcm2835_host
*host
)
744 struct device
*dev
= &host
->pdev
->dev
;
745 struct mmc_command
*cmd
= host
->cmd
;
748 sdcmd
= bcm2835_read_wait_sdcmd(host
, 100);
750 /* Check for errors */
751 if (sdcmd
& SDCMD_NEW_FLAG
) {
752 dev_err(dev
, "command never completed.\n");
753 bcm2835_dumpregs(host
);
754 host
->cmd
->error
= -EIO
;
755 bcm2835_finish_request(host
);
757 } else if (sdcmd
& SDCMD_FAIL_FLAG
) {
758 u32 sdhsts
= readl(host
->ioaddr
+ SDHSTS
);
760 /* Clear the errors */
761 writel(SDHSTS_ERROR_MASK
, host
->ioaddr
+ SDHSTS
);
763 if (!(sdhsts
& SDHSTS_CRC7_ERROR
) ||
764 (host
->cmd
->opcode
!= MMC_SEND_OP_COND
)) {
767 if (sdhsts
& SDHSTS_CMD_TIME_OUT
) {
768 host
->cmd
->error
= -ETIMEDOUT
;
770 dev_err(dev
, "unexpected command %d error\n",
772 bcm2835_dumpregs(host
);
773 host
->cmd
->error
= -EILSEQ
;
775 edm
= readl(host
->ioaddr
+ SDEDM
);
776 fsm
= edm
& SDEDM_FSM_MASK
;
777 if (fsm
== SDEDM_FSM_READWAIT
||
778 fsm
== SDEDM_FSM_WRITESTART1
)
779 /* Kick the FSM out of its wait */
780 writel(edm
| SDEDM_FORCE_DATA_MODE
,
781 host
->ioaddr
+ SDEDM
);
782 bcm2835_finish_request(host
);
787 if (cmd
->flags
& MMC_RSP_PRESENT
) {
788 if (cmd
->flags
& MMC_RSP_136
) {
791 for (i
= 0; i
< 4; i
++) {
793 readl(host
->ioaddr
+ SDRSP0
+ i
* 4);
796 cmd
->resp
[0] = readl(host
->ioaddr
+ SDRSP0
);
800 if (cmd
== host
->mrq
->sbc
) {
801 /* Finished CMD23, now send actual command. */
803 if (bcm2835_send_command(host
, host
->mrq
->cmd
)) {
804 if (host
->data
&& host
->dma_desc
)
805 /* DMA transfer starts now, PIO starts
808 bcm2835_start_dma(host
);
811 bcm2835_finish_command(host
);
813 } else if (cmd
== host
->mrq
->stop
) {
815 bcm2835_finish_request(host
);
817 /* Processed actual command. */
820 bcm2835_finish_request(host
);
821 else if (host
->data_complete
)
822 bcm2835_transfer_complete(host
);
826 static void bcm2835_timeout(struct work_struct
*work
)
828 struct delayed_work
*d
= to_delayed_work(work
);
829 struct bcm2835_host
*host
=
830 container_of(d
, struct bcm2835_host
, timeout_work
);
831 struct device
*dev
= &host
->pdev
->dev
;
833 mutex_lock(&host
->mutex
);
836 dev_err(dev
, "timeout waiting for hardware interrupt.\n");
837 bcm2835_dumpregs(host
);
839 bcm2835_reset(mmc_from_priv(host
));
842 host
->data
->error
= -ETIMEDOUT
;
843 bcm2835_finish_data(host
);
846 host
->cmd
->error
= -ETIMEDOUT
;
848 host
->mrq
->cmd
->error
= -ETIMEDOUT
;
850 bcm2835_finish_request(host
);
854 mutex_unlock(&host
->mutex
);
857 static bool bcm2835_check_cmd_error(struct bcm2835_host
*host
, u32 intmask
)
859 struct device
*dev
= &host
->pdev
->dev
;
861 if (!(intmask
& SDHSTS_ERROR_MASK
))
867 dev_err(dev
, "sdhost_busy_irq: intmask %08x\n", intmask
);
868 if (intmask
& SDHSTS_CRC7_ERROR
) {
869 host
->cmd
->error
= -EILSEQ
;
870 } else if (intmask
& (SDHSTS_CRC16_ERROR
|
871 SDHSTS_FIFO_ERROR
)) {
873 host
->mrq
->data
->error
= -EILSEQ
;
875 host
->cmd
->error
= -EILSEQ
;
876 } else if (intmask
& SDHSTS_REW_TIME_OUT
) {
878 host
->mrq
->data
->error
= -ETIMEDOUT
;
880 host
->cmd
->error
= -ETIMEDOUT
;
881 } else if (intmask
& SDHSTS_CMD_TIME_OUT
) {
882 host
->cmd
->error
= -ETIMEDOUT
;
884 bcm2835_dumpregs(host
);
888 static void bcm2835_check_data_error(struct bcm2835_host
*host
, u32 intmask
)
892 if (intmask
& (SDHSTS_CRC16_ERROR
| SDHSTS_FIFO_ERROR
))
893 host
->data
->error
= -EILSEQ
;
894 if (intmask
& SDHSTS_REW_TIME_OUT
)
895 host
->data
->error
= -ETIMEDOUT
;
898 static void bcm2835_busy_irq(struct bcm2835_host
*host
)
900 if (WARN_ON(!host
->cmd
)) {
901 bcm2835_dumpregs(host
);
905 if (WARN_ON(!host
->use_busy
)) {
906 bcm2835_dumpregs(host
);
909 host
->use_busy
= false;
911 bcm2835_finish_command(host
);
914 static void bcm2835_data_irq(struct bcm2835_host
*host
, u32 intmask
)
916 /* There are no dedicated data/space available interrupt
917 * status bits, so it is necessary to use the single shared
918 * data/space available FIFO status bits. It is therefore not
919 * an error to get here when there is no data transfer in
925 bcm2835_check_data_error(host
, intmask
);
926 if (host
->data
->error
)
929 if (host
->data
->flags
& MMC_DATA_WRITE
) {
930 /* Use the block interrupt for writes after the first block */
931 host
->hcfg
&= ~(SDHCFG_DATA_IRPT_EN
);
932 host
->hcfg
|= SDHCFG_BLOCK_IRPT_EN
;
933 writel(host
->hcfg
, host
->ioaddr
+ SDHCFG
);
934 bcm2835_transfer_pio(host
);
936 bcm2835_transfer_pio(host
);
938 if ((host
->blocks
== 0) || host
->data
->error
)
944 host
->hcfg
&= ~(SDHCFG_DATA_IRPT_EN
| SDHCFG_BLOCK_IRPT_EN
);
945 writel(host
->hcfg
, host
->ioaddr
+ SDHCFG
);
948 static void bcm2835_data_threaded_irq(struct bcm2835_host
*host
)
952 if ((host
->blocks
== 0) || host
->data
->error
)
953 bcm2835_finish_data(host
);
956 static void bcm2835_block_irq(struct bcm2835_host
*host
)
958 if (WARN_ON(!host
->data
)) {
959 bcm2835_dumpregs(host
);
963 if (!host
->dma_desc
) {
964 WARN_ON(!host
->blocks
);
965 if (host
->data
->error
|| (--host
->blocks
== 0))
966 bcm2835_finish_data(host
);
968 bcm2835_transfer_pio(host
);
969 } else if (host
->data
->flags
& MMC_DATA_WRITE
) {
970 bcm2835_finish_data(host
);
974 static irqreturn_t
bcm2835_irq(int irq
, void *dev_id
)
976 irqreturn_t result
= IRQ_NONE
;
977 struct bcm2835_host
*host
= dev_id
;
980 spin_lock(&host
->lock
);
982 intmask
= readl(host
->ioaddr
+ SDHSTS
);
984 writel(SDHSTS_BUSY_IRPT
|
988 host
->ioaddr
+ SDHSTS
);
990 if (intmask
& SDHSTS_BLOCK_IRPT
) {
991 bcm2835_check_data_error(host
, intmask
);
992 host
->irq_block
= true;
993 result
= IRQ_WAKE_THREAD
;
996 if (intmask
& SDHSTS_BUSY_IRPT
) {
997 if (!bcm2835_check_cmd_error(host
, intmask
)) {
998 host
->irq_busy
= true;
999 result
= IRQ_WAKE_THREAD
;
1001 result
= IRQ_HANDLED
;
1005 /* There is no true data interrupt status bit, so it is
1006 * necessary to qualify the data flag with the interrupt
1009 if ((intmask
& SDHSTS_DATA_FLAG
) &&
1010 (host
->hcfg
& SDHCFG_DATA_IRPT_EN
)) {
1011 bcm2835_data_irq(host
, intmask
);
1012 host
->irq_data
= true;
1013 result
= IRQ_WAKE_THREAD
;
1016 spin_unlock(&host
->lock
);
1021 static irqreturn_t
bcm2835_threaded_irq(int irq
, void *dev_id
)
1023 struct bcm2835_host
*host
= dev_id
;
1024 unsigned long flags
;
1025 bool block
, busy
, data
;
1027 spin_lock_irqsave(&host
->lock
, flags
);
1029 block
= host
->irq_block
;
1030 busy
= host
->irq_busy
;
1031 data
= host
->irq_data
;
1032 host
->irq_block
= false;
1033 host
->irq_busy
= false;
1034 host
->irq_data
= false;
1036 spin_unlock_irqrestore(&host
->lock
, flags
);
1038 mutex_lock(&host
->mutex
);
1041 bcm2835_block_irq(host
);
1043 bcm2835_busy_irq(host
);
1045 bcm2835_data_threaded_irq(host
);
1047 mutex_unlock(&host
->mutex
);
1052 static void bcm2835_dma_complete_work(struct work_struct
*work
)
1054 struct bcm2835_host
*host
=
1055 container_of(work
, struct bcm2835_host
, dma_work
);
1056 struct mmc_data
*data
;
1058 mutex_lock(&host
->mutex
);
1062 if (host
->dma_chan
) {
1063 dma_unmap_sg(host
->dma_chan
->device
->dev
,
1064 data
->sg
, data
->sg_len
,
1067 host
->dma_chan
= NULL
;
1070 if (host
->drain_words
) {
1071 unsigned long flags
;
1075 if (host
->drain_offset
& PAGE_MASK
) {
1076 host
->drain_page
+= host
->drain_offset
>> PAGE_SHIFT
;
1077 host
->drain_offset
&= ~PAGE_MASK
;
1079 local_irq_save(flags
);
1080 page
= kmap_atomic(host
->drain_page
);
1081 buf
= page
+ host
->drain_offset
;
1083 while (host
->drain_words
) {
1084 u32 edm
= readl(host
->ioaddr
+ SDEDM
);
1086 if ((edm
>> 4) & 0x1f)
1087 *(buf
++) = readl(host
->ioaddr
+ SDDATA
);
1088 host
->drain_words
--;
1091 kunmap_atomic(page
);
1092 local_irq_restore(flags
);
1095 bcm2835_finish_data(host
);
1097 mutex_unlock(&host
->mutex
);
1100 static void bcm2835_set_clock(struct bcm2835_host
*host
, unsigned int clock
)
1102 struct mmc_host
*mmc
= mmc_from_priv(host
);
1105 /* The SDCDIV register has 11 bits, and holds (div - 2). But
1106 * in data mode the max is 50MHz wihout a minimum, and only
1107 * the bottom 3 bits are used. Since the switch over is
1108 * automatic (unless we have marked the card as slow...),
1109 * chosen values have to make sense in both modes. Ident mode
1110 * must be 100-400KHz, so can range check the requested
1111 * clock. CMD15 must be used to return to data mode, so this
1114 * clock 250MHz -> 0->125MHz, 1->83.3MHz, 2->62.5MHz, 3->50.0MHz
1115 * 4->41.7MHz, 5->35.7MHz, 6->31.3MHz, 7->27.8MHz
1117 * 623->400KHz/27.8MHz
1118 * reset value (507)->491159/50MHz
1120 * BUT, the 3-bit clock divisor in data mode is too small if
1121 * the core clock is higher than 250MHz, so instead use the
1122 * SLOW_CARD configuration bit to force the use of the ident
1123 * clock divisor at all times.
1126 if (clock
< 100000) {
1127 /* Can't stop the clock, but make it as slow as possible
1130 host
->cdiv
= SDCDIV_MAX_CDIV
;
1131 writel(host
->cdiv
, host
->ioaddr
+ SDCDIV
);
1135 div
= host
->max_clk
/ clock
;
1138 if ((host
->max_clk
/ div
) > clock
)
1142 if (div
> SDCDIV_MAX_CDIV
)
1143 div
= SDCDIV_MAX_CDIV
;
1145 clock
= host
->max_clk
/ (div
+ 2);
1146 mmc
->actual_clock
= clock
;
1148 /* Calibrate some delays */
1150 host
->ns_per_fifo_word
= (1000000000 / clock
) *
1151 ((mmc
->caps
& MMC_CAP_4_BIT_DATA
) ? 8 : 32);
1154 writel(host
->cdiv
, host
->ioaddr
+ SDCDIV
);
1156 /* Set the timeout to 500ms */
1157 writel(mmc
->actual_clock
/ 2, host
->ioaddr
+ SDTOUT
);
1160 static void bcm2835_request(struct mmc_host
*mmc
, struct mmc_request
*mrq
)
1162 struct bcm2835_host
*host
= mmc_priv(mmc
);
1163 struct device
*dev
= &host
->pdev
->dev
;
1166 /* Reset the error statuses in case this is a retry */
1168 mrq
->sbc
->error
= 0;
1170 mrq
->cmd
->error
= 0;
1172 mrq
->data
->error
= 0;
1174 mrq
->stop
->error
= 0;
1176 if (mrq
->data
&& !is_power_of_2(mrq
->data
->blksz
)) {
1177 dev_err(dev
, "unsupported block size (%d bytes)\n",
1181 mrq
->cmd
->error
= -EINVAL
;
1183 mmc_request_done(mmc
, mrq
);
1187 mutex_lock(&host
->mutex
);
1192 edm
= readl(host
->ioaddr
+ SDEDM
);
1193 fsm
= edm
& SDEDM_FSM_MASK
;
1195 if ((fsm
!= SDEDM_FSM_IDENTMODE
) &&
1196 (fsm
!= SDEDM_FSM_DATAMODE
)) {
1197 dev_err(dev
, "previous command (%d) not complete (EDM %08x)\n",
1198 readl(host
->ioaddr
+ SDCMD
) & SDCMD_CMD_MASK
,
1200 bcm2835_dumpregs(host
);
1203 mrq
->cmd
->error
= -EILSEQ
;
1205 bcm2835_finish_request(host
);
1206 mutex_unlock(&host
->mutex
);
1210 if (host
->use_dma
&& mrq
->data
&& (mrq
->data
->blocks
> PIO_THRESHOLD
))
1211 bcm2835_prepare_dma(host
, mrq
->data
);
1213 host
->use_sbc
= !!mrq
->sbc
&& host
->mrq
->data
&&
1214 (host
->mrq
->data
->flags
& MMC_DATA_READ
);
1215 if (host
->use_sbc
) {
1216 if (bcm2835_send_command(host
, mrq
->sbc
)) {
1217 if (!host
->use_busy
)
1218 bcm2835_finish_command(host
);
1220 } else if (mrq
->cmd
&& bcm2835_send_command(host
, mrq
->cmd
)) {
1221 if (host
->data
&& host
->dma_desc
) {
1222 /* DMA transfer starts now, PIO starts after irq */
1223 bcm2835_start_dma(host
);
1226 if (!host
->use_busy
)
1227 bcm2835_finish_command(host
);
1230 mutex_unlock(&host
->mutex
);
1233 static void bcm2835_set_ios(struct mmc_host
*mmc
, struct mmc_ios
*ios
)
1235 struct bcm2835_host
*host
= mmc_priv(mmc
);
1237 mutex_lock(&host
->mutex
);
1239 if (!ios
->clock
|| ios
->clock
!= host
->clock
) {
1240 bcm2835_set_clock(host
, ios
->clock
);
1241 host
->clock
= ios
->clock
;
1245 host
->hcfg
&= ~SDHCFG_WIDE_EXT_BUS
;
1246 if (ios
->bus_width
== MMC_BUS_WIDTH_4
)
1247 host
->hcfg
|= SDHCFG_WIDE_EXT_BUS
;
1249 host
->hcfg
|= SDHCFG_WIDE_INT_BUS
;
1251 /* Disable clever clock switching, to cope with fast core clocks */
1252 host
->hcfg
|= SDHCFG_SLOW_CARD
;
1254 writel(host
->hcfg
, host
->ioaddr
+ SDHCFG
);
1256 mutex_unlock(&host
->mutex
);
1259 static const struct mmc_host_ops bcm2835_ops
= {
1260 .request
= bcm2835_request
,
1261 .set_ios
= bcm2835_set_ios
,
1262 .hw_reset
= bcm2835_reset
,
1265 static int bcm2835_add_host(struct bcm2835_host
*host
)
1267 struct mmc_host
*mmc
= mmc_from_priv(host
);
1268 struct device
*dev
= &host
->pdev
->dev
;
1269 char pio_limit_string
[20];
1272 if (!mmc
->f_max
|| mmc
->f_max
> host
->max_clk
)
1273 mmc
->f_max
= host
->max_clk
;
1274 mmc
->f_min
= host
->max_clk
/ SDCDIV_MAX_CDIV
;
1276 mmc
->max_busy_timeout
= ~0 / (mmc
->f_max
/ 1000);
1278 dev_dbg(dev
, "f_max %d, f_min %d, max_busy_timeout %d\n",
1279 mmc
->f_max
, mmc
->f_min
, mmc
->max_busy_timeout
);
1281 /* host controller capabilities */
1282 mmc
->caps
|= MMC_CAP_SD_HIGHSPEED
| MMC_CAP_MMC_HIGHSPEED
|
1283 MMC_CAP_NEEDS_POLL
| MMC_CAP_HW_RESET
| MMC_CAP_CMD23
;
1285 spin_lock_init(&host
->lock
);
1286 mutex_init(&host
->mutex
);
1288 if (!host
->dma_chan_rxtx
) {
1289 dev_warn(dev
, "unable to initialise DMA channel. Falling back to PIO\n");
1290 host
->use_dma
= false;
1292 host
->use_dma
= true;
1294 host
->dma_cfg_tx
.src_addr_width
= DMA_SLAVE_BUSWIDTH_4_BYTES
;
1295 host
->dma_cfg_tx
.dst_addr_width
= DMA_SLAVE_BUSWIDTH_4_BYTES
;
1296 host
->dma_cfg_tx
.slave_id
= 13; /* DREQ channel */
1297 host
->dma_cfg_tx
.direction
= DMA_MEM_TO_DEV
;
1298 host
->dma_cfg_tx
.src_addr
= 0;
1299 host
->dma_cfg_tx
.dst_addr
= host
->phys_addr
+ SDDATA
;
1301 host
->dma_cfg_rx
.src_addr_width
= DMA_SLAVE_BUSWIDTH_4_BYTES
;
1302 host
->dma_cfg_rx
.dst_addr_width
= DMA_SLAVE_BUSWIDTH_4_BYTES
;
1303 host
->dma_cfg_rx
.slave_id
= 13; /* DREQ channel */
1304 host
->dma_cfg_rx
.direction
= DMA_DEV_TO_MEM
;
1305 host
->dma_cfg_rx
.src_addr
= host
->phys_addr
+ SDDATA
;
1306 host
->dma_cfg_rx
.dst_addr
= 0;
1308 if (dmaengine_slave_config(host
->dma_chan_rxtx
,
1309 &host
->dma_cfg_tx
) != 0 ||
1310 dmaengine_slave_config(host
->dma_chan_rxtx
,
1311 &host
->dma_cfg_rx
) != 0)
1312 host
->use_dma
= false;
1315 mmc
->max_segs
= 128;
1316 mmc
->max_req_size
= min_t(size_t, 524288, dma_max_mapping_size(dev
));
1317 mmc
->max_seg_size
= mmc
->max_req_size
;
1318 mmc
->max_blk_size
= 1024;
1319 mmc
->max_blk_count
= 65535;
1321 /* report supported voltage ranges */
1322 mmc
->ocr_avail
= MMC_VDD_32_33
| MMC_VDD_33_34
;
1324 INIT_WORK(&host
->dma_work
, bcm2835_dma_complete_work
);
1325 INIT_DELAYED_WORK(&host
->timeout_work
, bcm2835_timeout
);
1327 /* Set interrupt enables */
1328 host
->hcfg
= SDHCFG_BUSY_IRPT_EN
;
1330 bcm2835_reset_internal(host
);
1332 ret
= request_threaded_irq(host
->irq
, bcm2835_irq
,
1333 bcm2835_threaded_irq
,
1334 0, mmc_hostname(mmc
), host
);
1336 dev_err(dev
, "failed to request IRQ %d: %d\n", host
->irq
, ret
);
1340 ret
= mmc_add_host(mmc
);
1342 free_irq(host
->irq
, host
);
1346 pio_limit_string
[0] = '\0';
1347 if (host
->use_dma
&& (PIO_THRESHOLD
> 0))
1348 sprintf(pio_limit_string
, " (>%d)", PIO_THRESHOLD
);
1349 dev_info(dev
, "loaded - DMA %s%s\n",
1350 host
->use_dma
? "enabled" : "disabled", pio_limit_string
);
1355 static int bcm2835_probe(struct platform_device
*pdev
)
1357 struct device
*dev
= &pdev
->dev
;
1359 struct bcm2835_host
*host
;
1360 struct mmc_host
*mmc
;
1361 const __be32
*regaddr_p
;
1364 dev_dbg(dev
, "%s\n", __func__
);
1365 mmc
= mmc_alloc_host(sizeof(*host
), dev
);
1369 mmc
->ops
= &bcm2835_ops
;
1370 host
= mmc_priv(mmc
);
1372 spin_lock_init(&host
->lock
);
1374 host
->ioaddr
= devm_platform_ioremap_resource(pdev
, 0);
1375 if (IS_ERR(host
->ioaddr
)) {
1376 ret
= PTR_ERR(host
->ioaddr
);
1380 /* Parse OF address directly to get the physical address for
1381 * DMA to our registers.
1383 regaddr_p
= of_get_address(pdev
->dev
.of_node
, 0, NULL
, NULL
);
1385 dev_err(dev
, "Can't get phys address\n");
1390 host
->phys_addr
= be32_to_cpup(regaddr_p
);
1392 host
->dma_chan
= NULL
;
1393 host
->dma_desc
= NULL
;
1395 host
->dma_chan_rxtx
= dma_request_chan(dev
, "rx-tx");
1396 if (IS_ERR(host
->dma_chan_rxtx
)) {
1397 ret
= PTR_ERR(host
->dma_chan_rxtx
);
1398 host
->dma_chan_rxtx
= NULL
;
1400 if (ret
== -EPROBE_DEFER
)
1403 /* Ignore errors to fall back to PIO mode */
1407 clk
= devm_clk_get(dev
, NULL
);
1409 ret
= dev_err_probe(dev
, PTR_ERR(clk
), "could not get clk\n");
1413 host
->max_clk
= clk_get_rate(clk
);
1415 host
->irq
= platform_get_irq(pdev
, 0);
1416 if (host
->irq
<= 0) {
1421 ret
= mmc_of_parse(mmc
);
1425 ret
= bcm2835_add_host(host
);
1429 platform_set_drvdata(pdev
, host
);
1431 dev_dbg(dev
, "%s -> OK\n", __func__
);
1436 dev_dbg(dev
, "%s -> err %d\n", __func__
, ret
);
1437 if (host
->dma_chan_rxtx
)
1438 dma_release_channel(host
->dma_chan_rxtx
);
1444 static int bcm2835_remove(struct platform_device
*pdev
)
1446 struct bcm2835_host
*host
= platform_get_drvdata(pdev
);
1447 struct mmc_host
*mmc
= mmc_from_priv(host
);
1449 mmc_remove_host(mmc
);
1451 writel(SDVDD_POWER_OFF
, host
->ioaddr
+ SDVDD
);
1453 free_irq(host
->irq
, host
);
1455 cancel_work_sync(&host
->dma_work
);
1456 cancel_delayed_work_sync(&host
->timeout_work
);
1458 if (host
->dma_chan_rxtx
)
1459 dma_release_channel(host
->dma_chan_rxtx
);
1466 static const struct of_device_id bcm2835_match
[] = {
1467 { .compatible
= "brcm,bcm2835-sdhost" },
1470 MODULE_DEVICE_TABLE(of
, bcm2835_match
);
1472 static struct platform_driver bcm2835_driver
= {
1473 .probe
= bcm2835_probe
,
1474 .remove
= bcm2835_remove
,
1476 .name
= "sdhost-bcm2835",
1477 .probe_type
= PROBE_PREFER_ASYNCHRONOUS
,
1478 .of_match_table
= bcm2835_match
,
1481 module_platform_driver(bcm2835_driver
);
1483 MODULE_ALIAS("platform:sdhost-bcm2835");
1484 MODULE_DESCRIPTION("BCM2835 SDHost driver");
1485 MODULE_LICENSE("GPL v2");
1486 MODULE_AUTHOR("Phil Elwell");