wlcore, wl1251: fix spelling: "Couldnt" -> "Couldn't" and remove error on -ENOMEM
[linux-2.6/btrfs-unstable.git] / drivers / mmc / host / bcm2835.c
blob229dc18f0581beb26733222be97f981b2038fb60
1 /*
2 * bcm2835 sdhost driver.
4 * The 2835 has two SD controllers: The Arasan sdhci controller
5 * (supported by the iproc driver) and a custom sdhost controller
6 * (supported by this driver).
8 * The sdhci controller supports both sdcard and sdio. The sdhost
9 * controller supports the sdcard only, but has better performance.
10 * Also note that the rpi3 has sdio wifi, so driving the sdcard with
11 * the sdhost controller allows to use the sdhci controller for wifi
12 * support.
14 * The configuration is done by devicetree via pin muxing. Both
15 * SD controller are available on the same pins (2 pin groups = pin 22
16 * to 27 + pin 48 to 53). So it's possible to use both SD controllers
17 * at the same time with different pin groups.
19 * Author: Phil Elwell <phil@raspberrypi.org>
20 * Copyright (C) 2015-2016 Raspberry Pi (Trading) Ltd.
22 * Based on
23 * mmc-bcm2835.c by Gellert Weisz
24 * which is, in turn, based on
25 * sdhci-bcm2708.c by Broadcom
26 * sdhci-bcm2835.c by Stephen Warren and Oleksandr Tymoshenko
27 * sdhci.c and sdhci-pci.c by Pierre Ossman
29 * This program is free software; you can redistribute it and/or modify it
30 * under the terms and conditions of the GNU General Public License,
31 * version 2, as published by the Free Software Foundation.
33 * This program is distributed in the hope it will be useful, but WITHOUT
34 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
35 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
36 * more details.
38 * You should have received a copy of the GNU General Public License
39 * along with this program. If not, see <http://www.gnu.org/licenses/>.
41 #include <linux/clk.h>
42 #include <linux/delay.h>
43 #include <linux/device.h>
44 #include <linux/dmaengine.h>
45 #include <linux/dma-mapping.h>
46 #include <linux/err.h>
47 #include <linux/highmem.h>
48 #include <linux/interrupt.h>
49 #include <linux/io.h>
50 #include <linux/iopoll.h>
51 #include <linux/module.h>
52 #include <linux/of_address.h>
53 #include <linux/of_irq.h>
54 #include <linux/platform_device.h>
55 #include <linux/scatterlist.h>
56 #include <linux/time.h>
57 #include <linux/workqueue.h>
59 #include <linux/mmc/host.h>
60 #include <linux/mmc/mmc.h>
61 #include <linux/mmc/sd.h>
63 #define SDCMD 0x00 /* Command to SD card - 16 R/W */
64 #define SDARG 0x04 /* Argument to SD card - 32 R/W */
65 #define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */
66 #define SDCDIV 0x0c /* Start value for clock divider - 11 R/W */
67 #define SDRSP0 0x10 /* SD card response (31:0) - 32 R */
68 #define SDRSP1 0x14 /* SD card response (63:32) - 32 R */
69 #define SDRSP2 0x18 /* SD card response (95:64) - 32 R */
70 #define SDRSP3 0x1c /* SD card response (127:96) - 32 R */
71 #define SDHSTS 0x20 /* SD host status - 11 R/W */
72 #define SDVDD 0x30 /* SD card power control - 1 R/W */
73 #define SDEDM 0x34 /* Emergency Debug Mode - 13 R/W */
74 #define SDHCFG 0x38 /* Host configuration - 2 R/W */
75 #define SDHBCT 0x3c /* Host byte count (debug) - 32 R/W */
76 #define SDDATA 0x40 /* Data to/from SD card - 32 R/W */
77 #define SDHBLC 0x50 /* Host block count (SDIO/SDHC) - 9 R/W */
79 #define SDCMD_NEW_FLAG 0x8000
80 #define SDCMD_FAIL_FLAG 0x4000
81 #define SDCMD_BUSYWAIT 0x800
82 #define SDCMD_NO_RESPONSE 0x400
83 #define SDCMD_LONG_RESPONSE 0x200
84 #define SDCMD_WRITE_CMD 0x80
85 #define SDCMD_READ_CMD 0x40
86 #define SDCMD_CMD_MASK 0x3f
88 #define SDCDIV_MAX_CDIV 0x7ff
90 #define SDHSTS_BUSY_IRPT 0x400
91 #define SDHSTS_BLOCK_IRPT 0x200
92 #define SDHSTS_SDIO_IRPT 0x100
93 #define SDHSTS_REW_TIME_OUT 0x80
94 #define SDHSTS_CMD_TIME_OUT 0x40
95 #define SDHSTS_CRC16_ERROR 0x20
96 #define SDHSTS_CRC7_ERROR 0x10
97 #define SDHSTS_FIFO_ERROR 0x08
98 /* Reserved */
99 /* Reserved */
100 #define SDHSTS_DATA_FLAG 0x01
102 #define SDHSTS_TRANSFER_ERROR_MASK (SDHSTS_CRC7_ERROR | \
103 SDHSTS_CRC16_ERROR | \
104 SDHSTS_REW_TIME_OUT | \
105 SDHSTS_FIFO_ERROR)
107 #define SDHSTS_ERROR_MASK (SDHSTS_CMD_TIME_OUT | \
108 SDHSTS_TRANSFER_ERROR_MASK)
110 #define SDHCFG_BUSY_IRPT_EN BIT(10)
111 #define SDHCFG_BLOCK_IRPT_EN BIT(8)
112 #define SDHCFG_SDIO_IRPT_EN BIT(5)
113 #define SDHCFG_DATA_IRPT_EN BIT(4)
114 #define SDHCFG_SLOW_CARD BIT(3)
115 #define SDHCFG_WIDE_EXT_BUS BIT(2)
116 #define SDHCFG_WIDE_INT_BUS BIT(1)
117 #define SDHCFG_REL_CMD_LINE BIT(0)
119 #define SDVDD_POWER_OFF 0
120 #define SDVDD_POWER_ON 1
122 #define SDEDM_FORCE_DATA_MODE BIT(19)
123 #define SDEDM_CLOCK_PULSE BIT(20)
124 #define SDEDM_BYPASS BIT(21)
126 #define SDEDM_WRITE_THRESHOLD_SHIFT 9
127 #define SDEDM_READ_THRESHOLD_SHIFT 14
128 #define SDEDM_THRESHOLD_MASK 0x1f
130 #define SDEDM_FSM_MASK 0xf
131 #define SDEDM_FSM_IDENTMODE 0x0
132 #define SDEDM_FSM_DATAMODE 0x1
133 #define SDEDM_FSM_READDATA 0x2
134 #define SDEDM_FSM_WRITEDATA 0x3
135 #define SDEDM_FSM_READWAIT 0x4
136 #define SDEDM_FSM_READCRC 0x5
137 #define SDEDM_FSM_WRITECRC 0x6
138 #define SDEDM_FSM_WRITEWAIT1 0x7
139 #define SDEDM_FSM_POWERDOWN 0x8
140 #define SDEDM_FSM_POWERUP 0x9
141 #define SDEDM_FSM_WRITESTART1 0xa
142 #define SDEDM_FSM_WRITESTART2 0xb
143 #define SDEDM_FSM_GENPULSES 0xc
144 #define SDEDM_FSM_WRITEWAIT2 0xd
145 #define SDEDM_FSM_STARTPOWDOWN 0xf
147 #define SDDATA_FIFO_WORDS 16
149 #define FIFO_READ_THRESHOLD 4
150 #define FIFO_WRITE_THRESHOLD 4
151 #define SDDATA_FIFO_PIO_BURST 8
153 #define PIO_THRESHOLD 1 /* Maximum block count for PIO (0 = always DMA) */
155 struct bcm2835_host {
156 spinlock_t lock;
157 struct mutex mutex;
159 void __iomem *ioaddr;
160 u32 phys_addr;
162 struct mmc_host *mmc;
163 struct platform_device *pdev;
165 int clock; /* Current clock speed */
166 unsigned int max_clk; /* Max possible freq */
167 struct work_struct dma_work;
168 struct delayed_work timeout_work; /* Timer for timeouts */
169 struct sg_mapping_iter sg_miter; /* SG state for PIO */
170 unsigned int blocks; /* remaining PIO blocks */
171 int irq; /* Device IRQ */
173 u32 ns_per_fifo_word;
175 /* cached registers */
176 u32 hcfg;
177 u32 cdiv;
179 struct mmc_request *mrq; /* Current request */
180 struct mmc_command *cmd; /* Current command */
181 struct mmc_data *data; /* Current data request */
182 bool data_complete:1;/* Data finished before cmd */
183 bool use_busy:1; /* Wait for busy interrupt */
184 bool use_sbc:1; /* Send CMD23 */
186 /* for threaded irq handler */
187 bool irq_block;
188 bool irq_busy;
189 bool irq_data;
191 /* DMA part */
192 struct dma_chan *dma_chan_rxtx;
193 struct dma_chan *dma_chan;
194 struct dma_slave_config dma_cfg_rx;
195 struct dma_slave_config dma_cfg_tx;
196 struct dma_async_tx_descriptor *dma_desc;
197 u32 dma_dir;
198 u32 drain_words;
199 struct page *drain_page;
200 u32 drain_offset;
201 bool use_dma;
204 static void bcm2835_dumpcmd(struct bcm2835_host *host, struct mmc_command *cmd,
205 const char *label)
207 struct device *dev = &host->pdev->dev;
209 if (!cmd)
210 return;
212 dev_dbg(dev, "%c%s op %d arg 0x%x flags 0x%x - resp %08x %08x %08x %08x, err %d\n",
213 (cmd == host->cmd) ? '>' : ' ',
214 label, cmd->opcode, cmd->arg, cmd->flags,
215 cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3],
216 cmd->error);
219 static void bcm2835_dumpregs(struct bcm2835_host *host)
221 struct mmc_request *mrq = host->mrq;
222 struct device *dev = &host->pdev->dev;
224 if (mrq) {
225 bcm2835_dumpcmd(host, mrq->sbc, "sbc");
226 bcm2835_dumpcmd(host, mrq->cmd, "cmd");
227 if (mrq->data) {
228 dev_dbg(dev, "data blocks %x blksz %x - err %d\n",
229 mrq->data->blocks,
230 mrq->data->blksz,
231 mrq->data->error);
233 bcm2835_dumpcmd(host, mrq->stop, "stop");
236 dev_dbg(dev, "=========== REGISTER DUMP ===========\n");
237 dev_dbg(dev, "SDCMD 0x%08x\n", readl(host->ioaddr + SDCMD));
238 dev_dbg(dev, "SDARG 0x%08x\n", readl(host->ioaddr + SDARG));
239 dev_dbg(dev, "SDTOUT 0x%08x\n", readl(host->ioaddr + SDTOUT));
240 dev_dbg(dev, "SDCDIV 0x%08x\n", readl(host->ioaddr + SDCDIV));
241 dev_dbg(dev, "SDRSP0 0x%08x\n", readl(host->ioaddr + SDRSP0));
242 dev_dbg(dev, "SDRSP1 0x%08x\n", readl(host->ioaddr + SDRSP1));
243 dev_dbg(dev, "SDRSP2 0x%08x\n", readl(host->ioaddr + SDRSP2));
244 dev_dbg(dev, "SDRSP3 0x%08x\n", readl(host->ioaddr + SDRSP3));
245 dev_dbg(dev, "SDHSTS 0x%08x\n", readl(host->ioaddr + SDHSTS));
246 dev_dbg(dev, "SDVDD 0x%08x\n", readl(host->ioaddr + SDVDD));
247 dev_dbg(dev, "SDEDM 0x%08x\n", readl(host->ioaddr + SDEDM));
248 dev_dbg(dev, "SDHCFG 0x%08x\n", readl(host->ioaddr + SDHCFG));
249 dev_dbg(dev, "SDHBCT 0x%08x\n", readl(host->ioaddr + SDHBCT));
250 dev_dbg(dev, "SDHBLC 0x%08x\n", readl(host->ioaddr + SDHBLC));
251 dev_dbg(dev, "===========================================\n");
254 static void bcm2835_reset_internal(struct bcm2835_host *host)
256 u32 temp;
258 writel(SDVDD_POWER_OFF, host->ioaddr + SDVDD);
259 writel(0, host->ioaddr + SDCMD);
260 writel(0, host->ioaddr + SDARG);
261 writel(0xf00000, host->ioaddr + SDTOUT);
262 writel(0, host->ioaddr + SDCDIV);
263 writel(0x7f8, host->ioaddr + SDHSTS); /* Write 1s to clear */
264 writel(0, host->ioaddr + SDHCFG);
265 writel(0, host->ioaddr + SDHBCT);
266 writel(0, host->ioaddr + SDHBLC);
268 /* Limit fifo usage due to silicon bug */
269 temp = readl(host->ioaddr + SDEDM);
270 temp &= ~((SDEDM_THRESHOLD_MASK << SDEDM_READ_THRESHOLD_SHIFT) |
271 (SDEDM_THRESHOLD_MASK << SDEDM_WRITE_THRESHOLD_SHIFT));
272 temp |= (FIFO_READ_THRESHOLD << SDEDM_READ_THRESHOLD_SHIFT) |
273 (FIFO_WRITE_THRESHOLD << SDEDM_WRITE_THRESHOLD_SHIFT);
274 writel(temp, host->ioaddr + SDEDM);
275 msleep(20);
276 writel(SDVDD_POWER_ON, host->ioaddr + SDVDD);
277 msleep(20);
278 host->clock = 0;
279 writel(host->hcfg, host->ioaddr + SDHCFG);
280 writel(host->cdiv, host->ioaddr + SDCDIV);
283 static void bcm2835_reset(struct mmc_host *mmc)
285 struct bcm2835_host *host = mmc_priv(mmc);
287 if (host->dma_chan)
288 dmaengine_terminate_sync(host->dma_chan);
289 bcm2835_reset_internal(host);
292 static void bcm2835_finish_command(struct bcm2835_host *host);
294 static void bcm2835_wait_transfer_complete(struct bcm2835_host *host)
296 int timediff;
297 u32 alternate_idle;
299 alternate_idle = (host->mrq->data->flags & MMC_DATA_READ) ?
300 SDEDM_FSM_READWAIT : SDEDM_FSM_WRITESTART1;
302 timediff = 0;
304 while (1) {
305 u32 edm, fsm;
307 edm = readl(host->ioaddr + SDEDM);
308 fsm = edm & SDEDM_FSM_MASK;
310 if ((fsm == SDEDM_FSM_IDENTMODE) ||
311 (fsm == SDEDM_FSM_DATAMODE))
312 break;
313 if (fsm == alternate_idle) {
314 writel(edm | SDEDM_FORCE_DATA_MODE,
315 host->ioaddr + SDEDM);
316 break;
319 timediff++;
320 if (timediff == 100000) {
321 dev_err(&host->pdev->dev,
322 "wait_transfer_complete - still waiting after %d retries\n",
323 timediff);
324 bcm2835_dumpregs(host);
325 host->mrq->data->error = -ETIMEDOUT;
326 return;
328 cpu_relax();
332 static void bcm2835_dma_complete(void *param)
334 struct bcm2835_host *host = param;
336 schedule_work(&host->dma_work);
339 static void bcm2835_transfer_block_pio(struct bcm2835_host *host, bool is_read)
341 unsigned long flags;
342 size_t blksize;
343 unsigned long wait_max;
345 blksize = host->data->blksz;
347 wait_max = jiffies + msecs_to_jiffies(500);
349 local_irq_save(flags);
351 while (blksize) {
352 int copy_words;
353 u32 hsts = 0;
354 size_t len;
355 u32 *buf;
357 if (!sg_miter_next(&host->sg_miter)) {
358 host->data->error = -EINVAL;
359 break;
362 len = min(host->sg_miter.length, blksize);
363 if (len % 4) {
364 host->data->error = -EINVAL;
365 break;
368 blksize -= len;
369 host->sg_miter.consumed = len;
371 buf = (u32 *)host->sg_miter.addr;
373 copy_words = len / 4;
375 while (copy_words) {
376 int burst_words, words;
377 u32 edm;
379 burst_words = min(SDDATA_FIFO_PIO_BURST, copy_words);
380 edm = readl(host->ioaddr + SDEDM);
381 if (is_read)
382 words = ((edm >> 4) & 0x1f);
383 else
384 words = SDDATA_FIFO_WORDS - ((edm >> 4) & 0x1f);
386 if (words < burst_words) {
387 int fsm_state = (edm & SDEDM_FSM_MASK);
388 struct device *dev = &host->pdev->dev;
390 if ((is_read &&
391 (fsm_state != SDEDM_FSM_READDATA &&
392 fsm_state != SDEDM_FSM_READWAIT &&
393 fsm_state != SDEDM_FSM_READCRC)) ||
394 (!is_read &&
395 (fsm_state != SDEDM_FSM_WRITEDATA &&
396 fsm_state != SDEDM_FSM_WRITESTART1 &&
397 fsm_state != SDEDM_FSM_WRITESTART2))) {
398 hsts = readl(host->ioaddr + SDHSTS);
399 dev_err(dev, "fsm %x, hsts %08x\n",
400 fsm_state, hsts);
401 if (hsts & SDHSTS_ERROR_MASK)
402 break;
405 if (time_after(jiffies, wait_max)) {
406 dev_err(dev, "PIO %s timeout - EDM %08x\n",
407 is_read ? "read" : "write",
408 edm);
409 hsts = SDHSTS_REW_TIME_OUT;
410 break;
412 ndelay((burst_words - words) *
413 host->ns_per_fifo_word);
414 continue;
415 } else if (words > copy_words) {
416 words = copy_words;
419 copy_words -= words;
421 while (words) {
422 if (is_read)
423 *(buf++) = readl(host->ioaddr + SDDATA);
424 else
425 writel(*(buf++), host->ioaddr + SDDATA);
426 words--;
430 if (hsts & SDHSTS_ERROR_MASK)
431 break;
434 sg_miter_stop(&host->sg_miter);
436 local_irq_restore(flags);
439 static void bcm2835_transfer_pio(struct bcm2835_host *host)
441 struct device *dev = &host->pdev->dev;
442 u32 sdhsts;
443 bool is_read;
445 is_read = (host->data->flags & MMC_DATA_READ) != 0;
446 bcm2835_transfer_block_pio(host, is_read);
448 sdhsts = readl(host->ioaddr + SDHSTS);
449 if (sdhsts & (SDHSTS_CRC16_ERROR |
450 SDHSTS_CRC7_ERROR |
451 SDHSTS_FIFO_ERROR)) {
452 dev_err(dev, "%s transfer error - HSTS %08x\n",
453 is_read ? "read" : "write", sdhsts);
454 host->data->error = -EILSEQ;
455 } else if ((sdhsts & (SDHSTS_CMD_TIME_OUT |
456 SDHSTS_REW_TIME_OUT))) {
457 dev_err(dev, "%s timeout error - HSTS %08x\n",
458 is_read ? "read" : "write", sdhsts);
459 host->data->error = -ETIMEDOUT;
463 static
464 void bcm2835_prepare_dma(struct bcm2835_host *host, struct mmc_data *data)
466 int len, dir_data, dir_slave;
467 struct dma_async_tx_descriptor *desc = NULL;
468 struct dma_chan *dma_chan;
470 dma_chan = host->dma_chan_rxtx;
471 if (data->flags & MMC_DATA_READ) {
472 dir_data = DMA_FROM_DEVICE;
473 dir_slave = DMA_DEV_TO_MEM;
474 } else {
475 dir_data = DMA_TO_DEVICE;
476 dir_slave = DMA_MEM_TO_DEV;
479 /* The block doesn't manage the FIFO DREQs properly for
480 * multi-block transfers, so don't attempt to DMA the final
481 * few words. Unfortunately this requires the final sg entry
482 * to be trimmed. N.B. This code demands that the overspill
483 * is contained in a single sg entry.
486 host->drain_words = 0;
487 if ((data->blocks > 1) && (dir_data == DMA_FROM_DEVICE)) {
488 struct scatterlist *sg;
489 u32 len;
490 int i;
492 len = min((u32)(FIFO_READ_THRESHOLD - 1) * 4,
493 (u32)data->blocks * data->blksz);
495 for_each_sg(data->sg, sg, data->sg_len, i) {
496 if (sg_is_last(sg)) {
497 WARN_ON(sg->length < len);
498 sg->length -= len;
499 host->drain_page = sg_page(sg);
500 host->drain_offset = sg->offset + sg->length;
503 host->drain_words = len / 4;
506 /* The parameters have already been validated, so this will not fail */
507 (void)dmaengine_slave_config(dma_chan,
508 (dir_data == DMA_FROM_DEVICE) ?
509 &host->dma_cfg_rx :
510 &host->dma_cfg_tx);
512 len = dma_map_sg(dma_chan->device->dev, data->sg, data->sg_len,
513 dir_data);
515 if (len > 0) {
516 desc = dmaengine_prep_slave_sg(dma_chan, data->sg,
517 len, dir_slave,
518 DMA_PREP_INTERRUPT |
519 DMA_CTRL_ACK);
522 if (desc) {
523 desc->callback = bcm2835_dma_complete;
524 desc->callback_param = host;
525 host->dma_desc = desc;
526 host->dma_chan = dma_chan;
527 host->dma_dir = dir_data;
531 static void bcm2835_start_dma(struct bcm2835_host *host)
533 dmaengine_submit(host->dma_desc);
534 dma_async_issue_pending(host->dma_chan);
537 static void bcm2835_set_transfer_irqs(struct bcm2835_host *host)
539 u32 all_irqs = SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN |
540 SDHCFG_BUSY_IRPT_EN;
542 if (host->dma_desc) {
543 host->hcfg = (host->hcfg & ~all_irqs) |
544 SDHCFG_BUSY_IRPT_EN;
545 } else {
546 host->hcfg = (host->hcfg & ~all_irqs) |
547 SDHCFG_DATA_IRPT_EN |
548 SDHCFG_BUSY_IRPT_EN;
551 writel(host->hcfg, host->ioaddr + SDHCFG);
554 static
555 void bcm2835_prepare_data(struct bcm2835_host *host, struct mmc_command *cmd)
557 struct mmc_data *data = cmd->data;
559 WARN_ON(host->data);
561 host->data = data;
562 if (!data)
563 return;
565 host->data_complete = false;
566 host->data->bytes_xfered = 0;
568 if (!host->dma_desc) {
569 /* Use PIO */
570 int flags = SG_MITER_ATOMIC;
572 if (data->flags & MMC_DATA_READ)
573 flags |= SG_MITER_TO_SG;
574 else
575 flags |= SG_MITER_FROM_SG;
576 sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
577 host->blocks = data->blocks;
580 bcm2835_set_transfer_irqs(host);
582 writel(data->blksz, host->ioaddr + SDHBCT);
583 writel(data->blocks, host->ioaddr + SDHBLC);
586 static u32 bcm2835_read_wait_sdcmd(struct bcm2835_host *host, u32 max_ms)
588 struct device *dev = &host->pdev->dev;
589 u32 value;
590 int ret;
592 ret = readl_poll_timeout(host->ioaddr + SDCMD, value,
593 !(value & SDCMD_NEW_FLAG), 1, 10);
594 if (ret == -ETIMEDOUT)
595 /* if it takes a while make poll interval bigger */
596 ret = readl_poll_timeout(host->ioaddr + SDCMD, value,
597 !(value & SDCMD_NEW_FLAG),
598 10, max_ms * 1000);
599 if (ret == -ETIMEDOUT)
600 dev_err(dev, "%s: timeout (%d ms)\n", __func__, max_ms);
602 return value;
605 static void bcm2835_finish_request(struct bcm2835_host *host)
607 struct dma_chan *terminate_chan = NULL;
608 struct mmc_request *mrq;
610 cancel_delayed_work(&host->timeout_work);
612 mrq = host->mrq;
614 host->mrq = NULL;
615 host->cmd = NULL;
616 host->data = NULL;
618 host->dma_desc = NULL;
619 terminate_chan = host->dma_chan;
620 host->dma_chan = NULL;
622 if (terminate_chan) {
623 int err = dmaengine_terminate_all(terminate_chan);
625 if (err)
626 dev_err(&host->pdev->dev,
627 "failed to terminate DMA (%d)\n", err);
630 mmc_request_done(host->mmc, mrq);
633 static
634 bool bcm2835_send_command(struct bcm2835_host *host, struct mmc_command *cmd)
636 struct device *dev = &host->pdev->dev;
637 u32 sdcmd, sdhsts;
638 unsigned long timeout;
640 WARN_ON(host->cmd);
642 sdcmd = bcm2835_read_wait_sdcmd(host, 100);
643 if (sdcmd & SDCMD_NEW_FLAG) {
644 dev_err(dev, "previous command never completed.\n");
645 bcm2835_dumpregs(host);
646 cmd->error = -EILSEQ;
647 bcm2835_finish_request(host);
648 return false;
651 if (!cmd->data && cmd->busy_timeout > 9000)
652 timeout = DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ;
653 else
654 timeout = 10 * HZ;
655 schedule_delayed_work(&host->timeout_work, timeout);
657 host->cmd = cmd;
659 /* Clear any error flags */
660 sdhsts = readl(host->ioaddr + SDHSTS);
661 if (sdhsts & SDHSTS_ERROR_MASK)
662 writel(sdhsts, host->ioaddr + SDHSTS);
664 if ((cmd->flags & MMC_RSP_136) && (cmd->flags & MMC_RSP_BUSY)) {
665 dev_err(dev, "unsupported response type!\n");
666 cmd->error = -EINVAL;
667 bcm2835_finish_request(host);
668 return false;
671 bcm2835_prepare_data(host, cmd);
673 writel(cmd->arg, host->ioaddr + SDARG);
675 sdcmd = cmd->opcode & SDCMD_CMD_MASK;
677 host->use_busy = false;
678 if (!(cmd->flags & MMC_RSP_PRESENT)) {
679 sdcmd |= SDCMD_NO_RESPONSE;
680 } else {
681 if (cmd->flags & MMC_RSP_136)
682 sdcmd |= SDCMD_LONG_RESPONSE;
683 if (cmd->flags & MMC_RSP_BUSY) {
684 sdcmd |= SDCMD_BUSYWAIT;
685 host->use_busy = true;
689 if (cmd->data) {
690 if (cmd->data->flags & MMC_DATA_WRITE)
691 sdcmd |= SDCMD_WRITE_CMD;
692 if (cmd->data->flags & MMC_DATA_READ)
693 sdcmd |= SDCMD_READ_CMD;
696 writel(sdcmd | SDCMD_NEW_FLAG, host->ioaddr + SDCMD);
698 return true;
701 static void bcm2835_transfer_complete(struct bcm2835_host *host)
703 struct mmc_data *data;
705 WARN_ON(!host->data_complete);
707 data = host->data;
708 host->data = NULL;
710 /* Need to send CMD12 if -
711 * a) open-ended multiblock transfer (no CMD23)
712 * b) error in multiblock transfer
714 if (host->mrq->stop && (data->error || !host->use_sbc)) {
715 if (bcm2835_send_command(host, host->mrq->stop)) {
716 /* No busy, so poll for completion */
717 if (!host->use_busy)
718 bcm2835_finish_command(host);
720 } else {
721 bcm2835_wait_transfer_complete(host);
722 bcm2835_finish_request(host);
726 static void bcm2835_finish_data(struct bcm2835_host *host)
728 struct device *dev = &host->pdev->dev;
729 struct mmc_data *data;
731 data = host->data;
733 host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN);
734 writel(host->hcfg, host->ioaddr + SDHCFG);
736 data->bytes_xfered = data->error ? 0 : (data->blksz * data->blocks);
738 host->data_complete = true;
740 if (host->cmd) {
741 /* Data managed to finish before the
742 * command completed. Make sure we do
743 * things in the proper order.
745 dev_dbg(dev, "Finished early - HSTS %08x\n",
746 readl(host->ioaddr + SDHSTS));
747 } else {
748 bcm2835_transfer_complete(host);
752 static void bcm2835_finish_command(struct bcm2835_host *host)
754 struct device *dev = &host->pdev->dev;
755 struct mmc_command *cmd = host->cmd;
756 u32 sdcmd;
758 sdcmd = bcm2835_read_wait_sdcmd(host, 100);
760 /* Check for errors */
761 if (sdcmd & SDCMD_NEW_FLAG) {
762 dev_err(dev, "command never completed.\n");
763 bcm2835_dumpregs(host);
764 host->cmd->error = -EIO;
765 bcm2835_finish_request(host);
766 return;
767 } else if (sdcmd & SDCMD_FAIL_FLAG) {
768 u32 sdhsts = readl(host->ioaddr + SDHSTS);
770 /* Clear the errors */
771 writel(SDHSTS_ERROR_MASK, host->ioaddr + SDHSTS);
773 if (!(sdhsts & SDHSTS_CRC7_ERROR) ||
774 (host->cmd->opcode != MMC_SEND_OP_COND)) {
775 if (sdhsts & SDHSTS_CMD_TIME_OUT) {
776 host->cmd->error = -ETIMEDOUT;
777 } else {
778 dev_err(dev, "unexpected command %d error\n",
779 host->cmd->opcode);
780 bcm2835_dumpregs(host);
781 host->cmd->error = -EILSEQ;
783 bcm2835_finish_request(host);
784 return;
788 if (cmd->flags & MMC_RSP_PRESENT) {
789 if (cmd->flags & MMC_RSP_136) {
790 int i;
792 for (i = 0; i < 4; i++) {
793 cmd->resp[3 - i] =
794 readl(host->ioaddr + SDRSP0 + i * 4);
796 } else {
797 cmd->resp[0] = readl(host->ioaddr + SDRSP0);
801 if (cmd == host->mrq->sbc) {
802 /* Finished CMD23, now send actual command. */
803 host->cmd = NULL;
804 if (bcm2835_send_command(host, host->mrq->cmd)) {
805 if (host->data && host->dma_desc)
806 /* DMA transfer starts now, PIO starts
807 * after irq
809 bcm2835_start_dma(host);
811 if (!host->use_busy)
812 bcm2835_finish_command(host);
814 } else if (cmd == host->mrq->stop) {
815 /* Finished CMD12 */
816 bcm2835_finish_request(host);
817 } else {
818 /* Processed actual command. */
819 host->cmd = NULL;
820 if (!host->data)
821 bcm2835_finish_request(host);
822 else if (host->data_complete)
823 bcm2835_transfer_complete(host);
827 static void bcm2835_timeout(struct work_struct *work)
829 struct delayed_work *d = to_delayed_work(work);
830 struct bcm2835_host *host =
831 container_of(d, struct bcm2835_host, timeout_work);
832 struct device *dev = &host->pdev->dev;
834 mutex_lock(&host->mutex);
836 if (host->mrq) {
837 dev_err(dev, "timeout waiting for hardware interrupt.\n");
838 bcm2835_dumpregs(host);
840 if (host->data) {
841 host->data->error = -ETIMEDOUT;
842 bcm2835_finish_data(host);
843 } else {
844 if (host->cmd)
845 host->cmd->error = -ETIMEDOUT;
846 else
847 host->mrq->cmd->error = -ETIMEDOUT;
849 bcm2835_finish_request(host);
853 mutex_unlock(&host->mutex);
856 static bool bcm2835_check_cmd_error(struct bcm2835_host *host, u32 intmask)
858 struct device *dev = &host->pdev->dev;
860 if (!(intmask & SDHSTS_ERROR_MASK))
861 return false;
863 if (!host->cmd)
864 return true;
866 dev_err(dev, "sdhost_busy_irq: intmask %08x\n", intmask);
867 if (intmask & SDHSTS_CRC7_ERROR) {
868 host->cmd->error = -EILSEQ;
869 } else if (intmask & (SDHSTS_CRC16_ERROR |
870 SDHSTS_FIFO_ERROR)) {
871 if (host->mrq->data)
872 host->mrq->data->error = -EILSEQ;
873 else
874 host->cmd->error = -EILSEQ;
875 } else if (intmask & SDHSTS_REW_TIME_OUT) {
876 if (host->mrq->data)
877 host->mrq->data->error = -ETIMEDOUT;
878 else
879 host->cmd->error = -ETIMEDOUT;
880 } else if (intmask & SDHSTS_CMD_TIME_OUT) {
881 host->cmd->error = -ETIMEDOUT;
883 bcm2835_dumpregs(host);
884 return true;
887 static void bcm2835_check_data_error(struct bcm2835_host *host, u32 intmask)
889 if (!host->data)
890 return;
891 if (intmask & (SDHSTS_CRC16_ERROR | SDHSTS_FIFO_ERROR))
892 host->data->error = -EILSEQ;
893 if (intmask & SDHSTS_REW_TIME_OUT)
894 host->data->error = -ETIMEDOUT;
897 static void bcm2835_busy_irq(struct bcm2835_host *host)
899 if (WARN_ON(!host->cmd)) {
900 bcm2835_dumpregs(host);
901 return;
904 if (WARN_ON(!host->use_busy)) {
905 bcm2835_dumpregs(host);
906 return;
908 host->use_busy = false;
910 bcm2835_finish_command(host);
913 static void bcm2835_data_irq(struct bcm2835_host *host, u32 intmask)
915 /* There are no dedicated data/space available interrupt
916 * status bits, so it is necessary to use the single shared
917 * data/space available FIFO status bits. It is therefore not
918 * an error to get here when there is no data transfer in
919 * progress.
921 if (!host->data)
922 return;
924 bcm2835_check_data_error(host, intmask);
925 if (host->data->error)
926 goto finished;
928 if (host->data->flags & MMC_DATA_WRITE) {
929 /* Use the block interrupt for writes after the first block */
930 host->hcfg &= ~(SDHCFG_DATA_IRPT_EN);
931 host->hcfg |= SDHCFG_BLOCK_IRPT_EN;
932 writel(host->hcfg, host->ioaddr + SDHCFG);
933 bcm2835_transfer_pio(host);
934 } else {
935 bcm2835_transfer_pio(host);
936 host->blocks--;
937 if ((host->blocks == 0) || host->data->error)
938 goto finished;
940 return;
942 finished:
943 host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN);
944 writel(host->hcfg, host->ioaddr + SDHCFG);
947 static void bcm2835_data_threaded_irq(struct bcm2835_host *host)
949 if (!host->data)
950 return;
951 if ((host->blocks == 0) || host->data->error)
952 bcm2835_finish_data(host);
955 static void bcm2835_block_irq(struct bcm2835_host *host)
957 if (WARN_ON(!host->data)) {
958 bcm2835_dumpregs(host);
959 return;
962 if (!host->dma_desc) {
963 WARN_ON(!host->blocks);
964 if (host->data->error || (--host->blocks == 0))
965 bcm2835_finish_data(host);
966 else
967 bcm2835_transfer_pio(host);
968 } else if (host->data->flags & MMC_DATA_WRITE) {
969 bcm2835_finish_data(host);
973 static irqreturn_t bcm2835_irq(int irq, void *dev_id)
975 irqreturn_t result = IRQ_NONE;
976 struct bcm2835_host *host = dev_id;
977 u32 intmask;
979 spin_lock(&host->lock);
981 intmask = readl(host->ioaddr + SDHSTS);
983 writel(SDHSTS_BUSY_IRPT |
984 SDHSTS_BLOCK_IRPT |
985 SDHSTS_SDIO_IRPT |
986 SDHSTS_DATA_FLAG,
987 host->ioaddr + SDHSTS);
989 if (intmask & SDHSTS_BLOCK_IRPT) {
990 bcm2835_check_data_error(host, intmask);
991 host->irq_block = true;
992 result = IRQ_WAKE_THREAD;
995 if (intmask & SDHSTS_BUSY_IRPT) {
996 if (!bcm2835_check_cmd_error(host, intmask)) {
997 host->irq_busy = true;
998 result = IRQ_WAKE_THREAD;
999 } else {
1000 result = IRQ_HANDLED;
1004 /* There is no true data interrupt status bit, so it is
1005 * necessary to qualify the data flag with the interrupt
1006 * enable bit.
1008 if ((intmask & SDHSTS_DATA_FLAG) &&
1009 (host->hcfg & SDHCFG_DATA_IRPT_EN)) {
1010 bcm2835_data_irq(host, intmask);
1011 host->irq_data = true;
1012 result = IRQ_WAKE_THREAD;
1015 spin_unlock(&host->lock);
1017 return result;
1020 static irqreturn_t bcm2835_threaded_irq(int irq, void *dev_id)
1022 struct bcm2835_host *host = dev_id;
1023 unsigned long flags;
1024 bool block, busy, data;
1026 spin_lock_irqsave(&host->lock, flags);
1028 block = host->irq_block;
1029 busy = host->irq_busy;
1030 data = host->irq_data;
1031 host->irq_block = false;
1032 host->irq_busy = false;
1033 host->irq_data = false;
1035 spin_unlock_irqrestore(&host->lock, flags);
1037 mutex_lock(&host->mutex);
1039 if (block)
1040 bcm2835_block_irq(host);
1041 if (busy)
1042 bcm2835_busy_irq(host);
1043 if (data)
1044 bcm2835_data_threaded_irq(host);
1046 mutex_unlock(&host->mutex);
1048 return IRQ_HANDLED;
1051 static void bcm2835_dma_complete_work(struct work_struct *work)
1053 struct bcm2835_host *host =
1054 container_of(work, struct bcm2835_host, dma_work);
1055 struct mmc_data *data = host->data;
1057 mutex_lock(&host->mutex);
1059 if (host->dma_chan) {
1060 dma_unmap_sg(host->dma_chan->device->dev,
1061 data->sg, data->sg_len,
1062 host->dma_dir);
1064 host->dma_chan = NULL;
1067 if (host->drain_words) {
1068 unsigned long flags;
1069 void *page;
1070 u32 *buf;
1072 if (host->drain_offset & PAGE_MASK) {
1073 host->drain_page += host->drain_offset >> PAGE_SHIFT;
1074 host->drain_offset &= ~PAGE_MASK;
1076 local_irq_save(flags);
1077 page = kmap_atomic(host->drain_page);
1078 buf = page + host->drain_offset;
1080 while (host->drain_words) {
1081 u32 edm = readl(host->ioaddr + SDEDM);
1083 if ((edm >> 4) & 0x1f)
1084 *(buf++) = readl(host->ioaddr + SDDATA);
1085 host->drain_words--;
1088 kunmap_atomic(page);
1089 local_irq_restore(flags);
1092 bcm2835_finish_data(host);
1094 mutex_unlock(&host->mutex);
1097 static void bcm2835_set_clock(struct bcm2835_host *host, unsigned int clock)
1099 int div;
1101 /* The SDCDIV register has 11 bits, and holds (div - 2). But
1102 * in data mode the max is 50MHz wihout a minimum, and only
1103 * the bottom 3 bits are used. Since the switch over is
1104 * automatic (unless we have marked the card as slow...),
1105 * chosen values have to make sense in both modes. Ident mode
1106 * must be 100-400KHz, so can range check the requested
1107 * clock. CMD15 must be used to return to data mode, so this
1108 * can be monitored.
1110 * clock 250MHz -> 0->125MHz, 1->83.3MHz, 2->62.5MHz, 3->50.0MHz
1111 * 4->41.7MHz, 5->35.7MHz, 6->31.3MHz, 7->27.8MHz
1113 * 623->400KHz/27.8MHz
1114 * reset value (507)->491159/50MHz
1116 * BUT, the 3-bit clock divisor in data mode is too small if
1117 * the core clock is higher than 250MHz, so instead use the
1118 * SLOW_CARD configuration bit to force the use of the ident
1119 * clock divisor at all times.
1122 if (clock < 100000) {
1123 /* Can't stop the clock, but make it as slow as possible
1124 * to show willing
1126 host->cdiv = SDCDIV_MAX_CDIV;
1127 writel(host->cdiv, host->ioaddr + SDCDIV);
1128 return;
1131 div = host->max_clk / clock;
1132 if (div < 2)
1133 div = 2;
1134 if ((host->max_clk / div) > clock)
1135 div++;
1136 div -= 2;
1138 if (div > SDCDIV_MAX_CDIV)
1139 div = SDCDIV_MAX_CDIV;
1141 clock = host->max_clk / (div + 2);
1142 host->mmc->actual_clock = clock;
1144 /* Calibrate some delays */
1146 host->ns_per_fifo_word = (1000000000 / clock) *
1147 ((host->mmc->caps & MMC_CAP_4_BIT_DATA) ? 8 : 32);
1149 host->cdiv = div;
1150 writel(host->cdiv, host->ioaddr + SDCDIV);
1152 /* Set the timeout to 500ms */
1153 writel(host->mmc->actual_clock / 2, host->ioaddr + SDTOUT);
1156 static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq)
1158 struct bcm2835_host *host = mmc_priv(mmc);
1159 struct device *dev = &host->pdev->dev;
1160 u32 edm, fsm;
1162 /* Reset the error statuses in case this is a retry */
1163 if (mrq->sbc)
1164 mrq->sbc->error = 0;
1165 if (mrq->cmd)
1166 mrq->cmd->error = 0;
1167 if (mrq->data)
1168 mrq->data->error = 0;
1169 if (mrq->stop)
1170 mrq->stop->error = 0;
1172 if (mrq->data && !is_power_of_2(mrq->data->blksz)) {
1173 dev_err(dev, "unsupported block size (%d bytes)\n",
1174 mrq->data->blksz);
1176 if (mrq->cmd)
1177 mrq->cmd->error = -EINVAL;
1179 mmc_request_done(mmc, mrq);
1180 return;
1183 if (host->use_dma && mrq->data && (mrq->data->blocks > PIO_THRESHOLD))
1184 bcm2835_prepare_dma(host, mrq->data);
1186 mutex_lock(&host->mutex);
1188 WARN_ON(host->mrq);
1189 host->mrq = mrq;
1191 edm = readl(host->ioaddr + SDEDM);
1192 fsm = edm & SDEDM_FSM_MASK;
1194 if ((fsm != SDEDM_FSM_IDENTMODE) &&
1195 (fsm != SDEDM_FSM_DATAMODE)) {
1196 dev_err(dev, "previous command (%d) not complete (EDM %08x)\n",
1197 readl(host->ioaddr + SDCMD) & SDCMD_CMD_MASK,
1198 edm);
1199 bcm2835_dumpregs(host);
1201 if (mrq->cmd)
1202 mrq->cmd->error = -EILSEQ;
1204 bcm2835_finish_request(host);
1205 mutex_unlock(&host->mutex);
1206 return;
1209 host->use_sbc = !!mrq->sbc && host->mrq->data &&
1210 (host->mrq->data->flags & MMC_DATA_READ);
1211 if (host->use_sbc) {
1212 if (bcm2835_send_command(host, mrq->sbc)) {
1213 if (!host->use_busy)
1214 bcm2835_finish_command(host);
1216 } else if (mrq->cmd && bcm2835_send_command(host, mrq->cmd)) {
1217 if (host->data && host->dma_desc) {
1218 /* DMA transfer starts now, PIO starts after irq */
1219 bcm2835_start_dma(host);
1222 if (!host->use_busy)
1223 bcm2835_finish_command(host);
1226 mutex_unlock(&host->mutex);
1229 static void bcm2835_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
1231 struct bcm2835_host *host = mmc_priv(mmc);
1233 mutex_lock(&host->mutex);
1235 if (!ios->clock || ios->clock != host->clock) {
1236 bcm2835_set_clock(host, ios->clock);
1237 host->clock = ios->clock;
1240 /* set bus width */
1241 host->hcfg &= ~SDHCFG_WIDE_EXT_BUS;
1242 if (ios->bus_width == MMC_BUS_WIDTH_4)
1243 host->hcfg |= SDHCFG_WIDE_EXT_BUS;
1245 host->hcfg |= SDHCFG_WIDE_INT_BUS;
1247 /* Disable clever clock switching, to cope with fast core clocks */
1248 host->hcfg |= SDHCFG_SLOW_CARD;
1250 writel(host->hcfg, host->ioaddr + SDHCFG);
1252 mutex_unlock(&host->mutex);
1255 static const struct mmc_host_ops bcm2835_ops = {
1256 .request = bcm2835_request,
1257 .set_ios = bcm2835_set_ios,
1258 .hw_reset = bcm2835_reset,
1261 static int bcm2835_add_host(struct bcm2835_host *host)
1263 struct mmc_host *mmc = host->mmc;
1264 struct device *dev = &host->pdev->dev;
1265 char pio_limit_string[20];
1266 int ret;
1268 mmc->f_max = host->max_clk;
1269 mmc->f_min = host->max_clk / SDCDIV_MAX_CDIV;
1271 mmc->max_busy_timeout = ~0 / (mmc->f_max / 1000);
1273 dev_dbg(dev, "f_max %d, f_min %d, max_busy_timeout %d\n",
1274 mmc->f_max, mmc->f_min, mmc->max_busy_timeout);
1276 /* host controller capabilities */
1277 mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED |
1278 MMC_CAP_NEEDS_POLL | MMC_CAP_HW_RESET | MMC_CAP_ERASE |
1279 MMC_CAP_CMD23;
1281 spin_lock_init(&host->lock);
1282 mutex_init(&host->mutex);
1284 if (IS_ERR_OR_NULL(host->dma_chan_rxtx)) {
1285 dev_warn(dev, "unable to initialise DMA channel. Falling back to PIO\n");
1286 host->use_dma = false;
1287 } else {
1288 host->use_dma = true;
1290 host->dma_cfg_tx.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1291 host->dma_cfg_tx.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1292 host->dma_cfg_tx.slave_id = 13; /* DREQ channel */
1293 host->dma_cfg_tx.direction = DMA_MEM_TO_DEV;
1294 host->dma_cfg_tx.src_addr = 0;
1295 host->dma_cfg_tx.dst_addr = host->phys_addr + SDDATA;
1297 host->dma_cfg_rx.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1298 host->dma_cfg_rx.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1299 host->dma_cfg_rx.slave_id = 13; /* DREQ channel */
1300 host->dma_cfg_rx.direction = DMA_DEV_TO_MEM;
1301 host->dma_cfg_rx.src_addr = host->phys_addr + SDDATA;
1302 host->dma_cfg_rx.dst_addr = 0;
1304 if (dmaengine_slave_config(host->dma_chan_rxtx,
1305 &host->dma_cfg_tx) != 0 ||
1306 dmaengine_slave_config(host->dma_chan_rxtx,
1307 &host->dma_cfg_rx) != 0)
1308 host->use_dma = false;
1311 mmc->max_segs = 128;
1312 mmc->max_req_size = 524288;
1313 mmc->max_seg_size = mmc->max_req_size;
1314 mmc->max_blk_size = 1024;
1315 mmc->max_blk_count = 65535;
1317 /* report supported voltage ranges */
1318 mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
1320 INIT_WORK(&host->dma_work, bcm2835_dma_complete_work);
1321 INIT_DELAYED_WORK(&host->timeout_work, bcm2835_timeout);
1323 /* Set interrupt enables */
1324 host->hcfg = SDHCFG_BUSY_IRPT_EN;
1326 bcm2835_reset_internal(host);
1328 ret = request_threaded_irq(host->irq, bcm2835_irq,
1329 bcm2835_threaded_irq,
1330 0, mmc_hostname(mmc), host);
1331 if (ret) {
1332 dev_err(dev, "failed to request IRQ %d: %d\n", host->irq, ret);
1333 return ret;
1336 ret = mmc_add_host(mmc);
1337 if (ret) {
1338 free_irq(host->irq, host);
1339 return ret;
1342 pio_limit_string[0] = '\0';
1343 if (host->use_dma && (PIO_THRESHOLD > 0))
1344 sprintf(pio_limit_string, " (>%d)", PIO_THRESHOLD);
1345 dev_info(dev, "loaded - DMA %s%s\n",
1346 host->use_dma ? "enabled" : "disabled", pio_limit_string);
1348 return 0;
1351 static int bcm2835_probe(struct platform_device *pdev)
1353 struct device *dev = &pdev->dev;
1354 struct clk *clk;
1355 struct resource *iomem;
1356 struct bcm2835_host *host;
1357 struct mmc_host *mmc;
1358 const __be32 *regaddr_p;
1359 int ret;
1361 dev_dbg(dev, "%s\n", __func__);
1362 mmc = mmc_alloc_host(sizeof(*host), dev);
1363 if (!mmc)
1364 return -ENOMEM;
1366 mmc->ops = &bcm2835_ops;
1367 host = mmc_priv(mmc);
1368 host->mmc = mmc;
1369 host->pdev = pdev;
1370 spin_lock_init(&host->lock);
1372 iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1373 host->ioaddr = devm_ioremap_resource(dev, iomem);
1374 if (IS_ERR(host->ioaddr)) {
1375 ret = PTR_ERR(host->ioaddr);
1376 goto err;
1379 /* Parse OF address directly to get the physical address for
1380 * DMA to our registers.
1382 regaddr_p = of_get_address(pdev->dev.of_node, 0, NULL, NULL);
1383 if (!regaddr_p) {
1384 dev_err(dev, "Can't get phys address\n");
1385 ret = -EINVAL;
1386 goto err;
1389 host->phys_addr = be32_to_cpup(regaddr_p);
1391 host->dma_chan = NULL;
1392 host->dma_desc = NULL;
1394 host->dma_chan_rxtx = dma_request_slave_channel(dev, "rx-tx");
1396 clk = devm_clk_get(dev, NULL);
1397 if (IS_ERR(clk)) {
1398 ret = PTR_ERR(clk);
1399 if (ret != -EPROBE_DEFER)
1400 dev_err(dev, "could not get clk: %d\n", ret);
1401 goto err;
1404 host->max_clk = clk_get_rate(clk);
1406 host->irq = platform_get_irq(pdev, 0);
1407 if (host->irq <= 0) {
1408 dev_err(dev, "get IRQ failed\n");
1409 ret = -EINVAL;
1410 goto err;
1413 ret = mmc_of_parse(mmc);
1414 if (ret)
1415 goto err;
1417 ret = bcm2835_add_host(host);
1418 if (ret)
1419 goto err;
1421 platform_set_drvdata(pdev, host);
1423 dev_dbg(dev, "%s -> OK\n", __func__);
1425 return 0;
1427 err:
1428 dev_dbg(dev, "%s -> err %d\n", __func__, ret);
1429 mmc_free_host(mmc);
1431 return ret;
1434 static int bcm2835_remove(struct platform_device *pdev)
1436 struct bcm2835_host *host = platform_get_drvdata(pdev);
1438 mmc_remove_host(host->mmc);
1440 writel(SDVDD_POWER_OFF, host->ioaddr + SDVDD);
1442 free_irq(host->irq, host);
1444 cancel_work_sync(&host->dma_work);
1445 cancel_delayed_work_sync(&host->timeout_work);
1447 mmc_free_host(host->mmc);
1448 platform_set_drvdata(pdev, NULL);
1450 return 0;
1453 static const struct of_device_id bcm2835_match[] = {
1454 { .compatible = "brcm,bcm2835-sdhost" },
1457 MODULE_DEVICE_TABLE(of, bcm2835_match);
1459 static struct platform_driver bcm2835_driver = {
1460 .probe = bcm2835_probe,
1461 .remove = bcm2835_remove,
1462 .driver = {
1463 .name = "sdhost-bcm2835",
1464 .of_match_table = bcm2835_match,
1467 module_platform_driver(bcm2835_driver);
1469 MODULE_ALIAS("platform:sdhost-bcm2835");
1470 MODULE_DESCRIPTION("BCM2835 SDHost driver");
1471 MODULE_LICENSE("GPL v2");
1472 MODULE_AUTHOR("Phil Elwell");