Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  *  linux/drivers/mmc/sdio.c
  3  *
  4  *  Copyright 2006-2007 Pierre Ossman
  5  *
  6  * This program is free software; you can redistribute it and/or modify
  7  * it under the terms of the GNU General Public License as published by
  8  * the Free Software Foundation; either version 2 of the License, or (at
  9  * your option) any later version.
 10  */
 11 
 12 #include <linux/err.h>
 13 
 14 #include <linux/mmc/host.h>
 15 #include <linux/mmc/card.h>
 16 #include <linux/mmc/sdio.h>
 17 #include <linux/mmc/sdio_func.h>
 18 
 19 #include "core.h"
 20 #include "bus.h"
 21 #include "sdio_bus.h"
 22 #include "mmc_ops.h"
 23 #include "sd_ops.h"
 24 #include "sdio_ops.h"
 25 #include "sdio_cis.h"
 26 
 27 static int sdio_read_fbr(struct sdio_func *func)
 28 {
 29         int ret;
 30         unsigned char data;
 31 
 32         ret = mmc_io_rw_direct(func->card, 0, 0,
 33                 SDIO_FBR_BASE(func->num) + SDIO_FBR_STD_IF, 0, &data);
 34         if (ret)
 35                 goto out;
 36 
 37         data &= 0x0f;
 38 
 39         if (data == 0x0f) {
 40                 ret = mmc_io_rw_direct(func->card, 0, 0,
 41                         SDIO_FBR_BASE(func->num) + SDIO_FBR_STD_IF_EXT, 0, &data);
 42                 if (ret)
 43                         goto out;
 44         }
 45 
 46         func->class = data;
 47 
 48 out:
 49         return ret;
 50 }
 51 
 52 static int sdio_init_func(struct mmc_card *card, unsigned int fn)
 53 {
 54         int ret;
 55         struct sdio_func *func;
 56 
 57         BUG_ON(fn > SDIO_MAX_FUNCS);
 58 
 59         func = sdio_alloc_func(card);
 60         if (IS_ERR(func))
 61                 return PTR_ERR(func);
 62 
 63         func->num = fn;
 64 
 65         ret = sdio_read_fbr(func);
 66         if (ret)
 67                 goto fail;
 68 
 69         ret = sdio_read_func_cis(func);
 70         if (ret)
 71                 goto fail;
 72 
 73         card->sdio_func[fn - 1] = func;
 74 
 75         return 0;
 76 
 77 fail:
 78         /*
 79          * It is okay to remove the function here even though we hold
 80          * the host lock as we haven't registered the device yet.
 81          */
 82         sdio_remove_func(func);
 83         return ret;
 84 }
 85 
 86 static int sdio_read_cccr(struct mmc_card *card)
 87 {
 88         int ret;
 89         int cccr_vsn;
 90         unsigned char data;
 91 
 92         memset(&card->cccr, 0, sizeof(struct sdio_cccr));
 93 
 94         ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_CCCR, 0, &data);
 95         if (ret)
 96                 goto out;
 97 
 98         cccr_vsn = data & 0x0f;
 99 
100         if (cccr_vsn > SDIO_CCCR_REV_1_20) {
101                 printk(KERN_ERR "%s: unrecognised CCCR structure version %d\n",
102                         mmc_hostname(card->host), cccr_vsn);
103                 return -EINVAL;
104         }
105 
106         card->cccr.sdio_vsn = (data & 0xf0) >> 4;
107 
108         ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_CAPS, 0, &data);
109         if (ret)
110                 goto out;
111 
112         if (data & SDIO_CCCR_CAP_SMB)
113                 card->cccr.multi_block = 1;
114         if (data & SDIO_CCCR_CAP_LSC)
115                 card->cccr.low_speed = 1;
116         if (data & SDIO_CCCR_CAP_4BLS)
117                 card->cccr.wide_bus = 1;
118 
119         if (cccr_vsn >= SDIO_CCCR_REV_1_10) {
120                 ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_POWER, 0, &data);
121                 if (ret)
122                         goto out;
123 
124                 if (data & SDIO_POWER_SMPC)
125                         card->cccr.high_power = 1;
126         }
127 
128         if (cccr_vsn >= SDIO_CCCR_REV_1_20) {
129                 ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &data);
130                 if (ret)
131                         goto out;
132 
133                 if (data & SDIO_SPEED_SHS)
134                         card->cccr.high_speed = 1;
135         }
136 
137 out:
138         return ret;
139 }
140 
141 static int sdio_enable_wide(struct mmc_card *card)
142 {
143         int ret;
144         u8 ctrl;
145 
146         if (!(card->host->caps & MMC_CAP_4_BIT_DATA))
147                 return 0;
148 
149         if (card->cccr.low_speed && !card->cccr.wide_bus)
150                 return 0;
151 
152         ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_IF, 0, &ctrl);
153         if (ret)
154                 return ret;
155 
156         ctrl |= SDIO_BUS_WIDTH_4BIT;
157 
158         ret = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_IF, ctrl, NULL);
159         if (ret)
160                 return ret;
161 
162         mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
163 
164         return 0;
165 }
166 
167 /*
168  * Host is being removed. Free up the current card.
169  */
170 static void mmc_sdio_remove(struct mmc_host *host)
171 {
172         int i;
173 
174         BUG_ON(!host);
175         BUG_ON(!host->card);
176 
177         for (i = 0;i < host->card->sdio_funcs;i++) {
178                 if (host->card->sdio_func[i]) {
179                         sdio_remove_func(host->card->sdio_func[i]);
180                         host->card->sdio_func[i] = NULL;
181                 }
182         }
183 
184         mmc_remove_card(host->card);
185         host->card = NULL;
186 }
187 
188 /*
189  * Card detection callback from host.
190  */
191 static void mmc_sdio_detect(struct mmc_host *host)
192 {
193         int err;
194 
195         BUG_ON(!host);
196         BUG_ON(!host->card);
197 
198         mmc_claim_host(host);
199 
200         /*
201          * Just check if our card has been removed.
202          */
203         err = mmc_select_card(host->card);
204 
205         mmc_release_host(host);
206 
207         if (err) {
208                 mmc_sdio_remove(host);
209 
210                 mmc_claim_host(host);
211                 mmc_detach_bus(host);
212                 mmc_release_host(host);
213         }
214 }
215 
216 
217 static const struct mmc_bus_ops mmc_sdio_ops = {
218         .remove = mmc_sdio_remove,
219         .detect = mmc_sdio_detect,
220 };
221 
222 
223 /*
224  * Starting point for SDIO card init.
225  */
226 int mmc_attach_sdio(struct mmc_host *host, u32 ocr)
227 {
228         int err;
229         int i, funcs;
230         struct mmc_card *card;
231 
232         BUG_ON(!host);
233         WARN_ON(!host->claimed);
234 
235         mmc_attach_bus(host, &mmc_sdio_ops);
236 
237         /*
238          * Sanity check the voltages that the card claims to
239          * support.
240          */
241         if (ocr & 0x7F) {
242                 printk(KERN_WARNING "%s: card claims to support voltages "
243                        "below the defined range. These will be ignored.\n",
244                        mmc_hostname(host));
245                 ocr &= ~0x7F;
246         }
247 
248         if (ocr & MMC_VDD_165_195) {
249                 printk(KERN_WARNING "%s: SDIO card claims to support the "
250                        "incompletely defined 'low voltage range'. This "
251                        "will be ignored.\n", mmc_hostname(host));
252                 ocr &= ~MMC_VDD_165_195;
253         }
254 
255         host->ocr = mmc_select_voltage(host, ocr);
256 
257         /*
258          * Can we support the voltage(s) of the card(s)?
259          */
260         if (!host->ocr) {
261                 err = -EINVAL;
262                 goto err;
263         }
264 
265         /*
266          * Inform the card of the voltage
267          */
268         err = mmc_send_io_op_cond(host, host->ocr, &ocr);
269         if (err)
270                 goto err;
271 
272         /*
273          * For SPI, enable CRC as appropriate.
274          */
275         if (mmc_host_is_spi(host)) {
276                 err = mmc_spi_set_crc(host, use_spi_crc);
277                 if (err)
278                         goto err;
279         }
280 
281         /*
282          * The number of functions on the card is encoded inside
283          * the ocr.
284          */
285         funcs = (ocr & 0x70000000) >> 28;
286 
287         /*
288          * Allocate card structure.
289          */
290         card = mmc_alloc_card(host, NULL);
291         if (IS_ERR(card)) {
292                 err = PTR_ERR(card);
293                 goto err;
294         }
295 
296         card->type = MMC_TYPE_SDIO;
297         card->sdio_funcs = funcs;
298 
299         host->card = card;
300 
301         /*
302          * For native busses:  set card RCA and quit open drain mode.
303          */
304         if (!mmc_host_is_spi(host)) {
305                 err = mmc_send_relative_addr(host, &card->rca);
306                 if (err)
307                         goto remove;
308 
309                 mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);
310         }
311 
312         /*
313          * Select card, as all following commands rely on that.
314          */
315         if (!mmc_host_is_spi(host)) {
316                 err = mmc_select_card(card);
317                 if (err)
318                         goto remove;
319         }
320 
321         /*
322          * Read the common registers.
323          */
324         err = sdio_read_cccr(card);
325         if (err)
326                 goto remove;
327 
328         /*
329          * Read the common CIS tuples.
330          */
331         err = sdio_read_common_cis(card);
332         if (err)
333                 goto remove;
334 
335         /*
336          * No support for high-speed yet, so just set
337          * the card's maximum speed.
338          */
339         mmc_set_clock(host, card->cis.max_dtr);
340 
341         /*
342          * Switch to wider bus (if supported).
343          */
344         err = sdio_enable_wide(card);
345         if (err)
346                 goto remove;
347 
348         /*
349          * Initialize (but don't add) all present functions.
350          */
351         for (i = 0;i < funcs;i++) {
352                 err = sdio_init_func(host->card, i + 1);
353                 if (err)
354                         goto remove;
355         }
356 
357         mmc_release_host(host);
358 
359         /*
360          * First add the card to the driver model...
361          */
362         err = mmc_add_card(host->card);
363         if (err)
364                 goto remove_added;
365 
366         /*
367          * ...then the SDIO functions.
368          */
369         for (i = 0;i < funcs;i++) {
370                 err = sdio_add_func(host->card->sdio_func[i]);
371                 if (err)
372                         goto remove_added;
373         }
374 
375         return 0;
376 
377 
378 remove_added:
379         /* Remove without lock if the device has been added. */
380         mmc_sdio_remove(host);
381         mmc_claim_host(host);
382 remove:
383         /* And with lock if it hasn't been added. */
384         if (host->card)
385                 mmc_sdio_remove(host);
386 err:
387         mmc_detach_bus(host);
388         mmc_release_host(host);
389 
390         printk(KERN_ERR "%s: error %d whilst initialising SDIO card\n",
391                 mmc_hostname(host), err);
392 
393         return err;
394 }
395 
396 
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