mmc: dw-mmc: support DesignWare MMC Controller
[platform/kernel/u-boot.git] / drivers / mmc / omap_hsmmc.c
1 /*
2  * (C) Copyright 2008
3  * Texas Instruments, <www.ti.com>
4  * Sukumar Ghorai <s-ghorai@ti.com>
5  *
6  * See file CREDITS for list of people who contributed to this
7  * project.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation's version 2 of
12  * the License.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
22  * MA 02111-1307 USA
23  */
24
25 #include <config.h>
26 #include <common.h>
27 #include <mmc.h>
28 #include <part.h>
29 #include <i2c.h>
30 #include <twl4030.h>
31 #include <twl6030.h>
32 #include <twl6035.h>
33 #include <asm/io.h>
34 #include <asm/arch/mmc_host_def.h>
35 #include <asm/arch/sys_proto.h>
36
37 /* common definitions for all OMAPs */
38 #define SYSCTL_SRC      (1 << 25)
39 #define SYSCTL_SRD      (1 << 26)
40
41 /* If we fail after 1 second wait, something is really bad */
42 #define MAX_RETRY_MS    1000
43
44 static int mmc_read_data(struct hsmmc *mmc_base, char *buf, unsigned int size);
45 static int mmc_write_data(struct hsmmc *mmc_base, const char *buf,
46                         unsigned int siz);
47 static struct mmc hsmmc_dev[2];
48
49 #if defined(CONFIG_OMAP44XX) && defined(CONFIG_TWL6030_POWER)
50 static void omap4_vmmc_pbias_config(struct mmc *mmc)
51 {
52         u32 value = 0;
53         struct omap_sys_ctrl_regs *const ctrl =
54                 (struct omap_sys_ctrl_regs *) SYSCTRL_GENERAL_CORE_BASE;
55
56
57         value = readl(&ctrl->control_pbiaslite);
58         value &= ~(MMC1_PBIASLITE_PWRDNZ | MMC1_PWRDNZ);
59         writel(value, &ctrl->control_pbiaslite);
60         /* set VMMC to 3V */
61         twl6030_power_mmc_init();
62         value = readl(&ctrl->control_pbiaslite);
63         value |= MMC1_PBIASLITE_VMODE | MMC1_PBIASLITE_PWRDNZ | MMC1_PWRDNZ;
64         writel(value, &ctrl->control_pbiaslite);
65 }
66 #endif
67
68 #if defined(CONFIG_OMAP54XX) && defined(CONFIG_TWL6035_POWER)
69 static void omap5_pbias_config(struct mmc *mmc)
70 {
71         u32 value = 0;
72         struct omap_sys_ctrl_regs *const ctrl =
73                 (struct omap_sys_ctrl_regs *) SYSCTRL_GENERAL_CORE_BASE;
74
75         value = readl(&ctrl->control_pbias);
76         value &= ~(SDCARD_PWRDNZ | SDCARD_BIAS_PWRDNZ);
77         value |= SDCARD_BIAS_HIZ_MODE;
78         writel(value, &ctrl->control_pbias);
79
80         twl6035_mmc1_poweron_ldo();
81
82         value = readl(&ctrl->control_pbias);
83         value &= ~SDCARD_BIAS_HIZ_MODE;
84         value |= SDCARD_PBIASLITE_VMODE | SDCARD_PWRDNZ | SDCARD_BIAS_PWRDNZ;
85         writel(value, &ctrl->control_pbias);
86
87         value = readl(&ctrl->control_pbias);
88         if (value & (1 << 23)) {
89                 value &= ~(SDCARD_PWRDNZ | SDCARD_BIAS_PWRDNZ);
90                 value |= SDCARD_BIAS_HIZ_MODE;
91                 writel(value, &ctrl->control_pbias);
92         }
93 }
94 #endif
95
96 unsigned char mmc_board_init(struct mmc *mmc)
97 {
98 #if defined(CONFIG_OMAP34XX)
99         t2_t *t2_base = (t2_t *)T2_BASE;
100         struct prcm *prcm_base = (struct prcm *)PRCM_BASE;
101         u32 pbias_lite;
102
103         pbias_lite = readl(&t2_base->pbias_lite);
104         pbias_lite &= ~(PBIASLITEPWRDNZ1 | PBIASLITEPWRDNZ0);
105         writel(pbias_lite, &t2_base->pbias_lite);
106 #endif
107 #if defined(CONFIG_TWL4030_POWER)
108         twl4030_power_mmc_init();
109         mdelay(100);    /* ramp-up delay from Linux code */
110 #endif
111 #if defined(CONFIG_OMAP34XX)
112         writel(pbias_lite | PBIASLITEPWRDNZ1 |
113                 PBIASSPEEDCTRL0 | PBIASLITEPWRDNZ0,
114                 &t2_base->pbias_lite);
115
116         writel(readl(&t2_base->devconf0) | MMCSDIO1ADPCLKISEL,
117                 &t2_base->devconf0);
118
119         writel(readl(&t2_base->devconf1) | MMCSDIO2ADPCLKISEL,
120                 &t2_base->devconf1);
121
122         /* Change from default of 52MHz to 26MHz if necessary */
123         if (!(mmc->host_caps & MMC_MODE_HS_52MHz))
124                 writel(readl(&t2_base->ctl_prog_io1) & ~CTLPROGIO1SPEEDCTRL,
125                         &t2_base->ctl_prog_io1);
126
127         writel(readl(&prcm_base->fclken1_core) |
128                 EN_MMC1 | EN_MMC2 | EN_MMC3,
129                 &prcm_base->fclken1_core);
130
131         writel(readl(&prcm_base->iclken1_core) |
132                 EN_MMC1 | EN_MMC2 | EN_MMC3,
133                 &prcm_base->iclken1_core);
134 #endif
135
136 #if defined(CONFIG_OMAP44XX) && defined(CONFIG_TWL6030_POWER)
137         /* PBIAS config needed for MMC1 only */
138         if (mmc->block_dev.dev == 0)
139                 omap4_vmmc_pbias_config(mmc);
140 #endif
141 #if defined(CONFIG_OMAP54XX) && defined(CONFIG_TWL6035_POWER)
142         if (mmc->block_dev.dev == 0)
143                 omap5_pbias_config(mmc);
144 #endif
145
146         return 0;
147 }
148
149 void mmc_init_stream(struct hsmmc *mmc_base)
150 {
151         ulong start;
152
153         writel(readl(&mmc_base->con) | INIT_INITSTREAM, &mmc_base->con);
154
155         writel(MMC_CMD0, &mmc_base->cmd);
156         start = get_timer(0);
157         while (!(readl(&mmc_base->stat) & CC_MASK)) {
158                 if (get_timer(0) - start > MAX_RETRY_MS) {
159                         printf("%s: timedout waiting for cc!\n", __func__);
160                         return;
161                 }
162         }
163         writel(CC_MASK, &mmc_base->stat)
164                 ;
165         writel(MMC_CMD0, &mmc_base->cmd)
166                 ;
167         start = get_timer(0);
168         while (!(readl(&mmc_base->stat) & CC_MASK)) {
169                 if (get_timer(0) - start > MAX_RETRY_MS) {
170                         printf("%s: timedout waiting for cc2!\n", __func__);
171                         return;
172                 }
173         }
174         writel(readl(&mmc_base->con) & ~INIT_INITSTREAM, &mmc_base->con);
175 }
176
177
178 static int mmc_init_setup(struct mmc *mmc)
179 {
180         struct hsmmc *mmc_base = (struct hsmmc *)mmc->priv;
181         unsigned int reg_val;
182         unsigned int dsor;
183         ulong start;
184
185         mmc_board_init(mmc);
186
187         writel(readl(&mmc_base->sysconfig) | MMC_SOFTRESET,
188                 &mmc_base->sysconfig);
189         start = get_timer(0);
190         while ((readl(&mmc_base->sysstatus) & RESETDONE) == 0) {
191                 if (get_timer(0) - start > MAX_RETRY_MS) {
192                         printf("%s: timedout waiting for cc2!\n", __func__);
193                         return TIMEOUT;
194                 }
195         }
196         writel(readl(&mmc_base->sysctl) | SOFTRESETALL, &mmc_base->sysctl);
197         start = get_timer(0);
198         while ((readl(&mmc_base->sysctl) & SOFTRESETALL) != 0x0) {
199                 if (get_timer(0) - start > MAX_RETRY_MS) {
200                         printf("%s: timedout waiting for softresetall!\n",
201                                 __func__);
202                         return TIMEOUT;
203                 }
204         }
205         writel(DTW_1_BITMODE | SDBP_PWROFF | SDVS_3V0, &mmc_base->hctl);
206         writel(readl(&mmc_base->capa) | VS30_3V0SUP | VS18_1V8SUP,
207                 &mmc_base->capa);
208
209         reg_val = readl(&mmc_base->con) & RESERVED_MASK;
210
211         writel(CTPL_MMC_SD | reg_val | WPP_ACTIVEHIGH | CDP_ACTIVEHIGH |
212                 MIT_CTO | DW8_1_4BITMODE | MODE_FUNC | STR_BLOCK |
213                 HR_NOHOSTRESP | INIT_NOINIT | NOOPENDRAIN, &mmc_base->con);
214
215         dsor = 240;
216         mmc_reg_out(&mmc_base->sysctl, (ICE_MASK | DTO_MASK | CEN_MASK),
217                 (ICE_STOP | DTO_15THDTO | CEN_DISABLE));
218         mmc_reg_out(&mmc_base->sysctl, ICE_MASK | CLKD_MASK,
219                 (dsor << CLKD_OFFSET) | ICE_OSCILLATE);
220         start = get_timer(0);
221         while ((readl(&mmc_base->sysctl) & ICS_MASK) == ICS_NOTREADY) {
222                 if (get_timer(0) - start > MAX_RETRY_MS) {
223                         printf("%s: timedout waiting for ics!\n", __func__);
224                         return TIMEOUT;
225                 }
226         }
227         writel(readl(&mmc_base->sysctl) | CEN_ENABLE, &mmc_base->sysctl);
228
229         writel(readl(&mmc_base->hctl) | SDBP_PWRON, &mmc_base->hctl);
230
231         writel(IE_BADA | IE_CERR | IE_DEB | IE_DCRC | IE_DTO | IE_CIE |
232                 IE_CEB | IE_CCRC | IE_CTO | IE_BRR | IE_BWR | IE_TC | IE_CC,
233                 &mmc_base->ie);
234
235         mmc_init_stream(mmc_base);
236
237         return 0;
238 }
239
240 /*
241  * MMC controller internal finite state machine reset
242  *
243  * Used to reset command or data internal state machines, using respectively
244  * SRC or SRD bit of SYSCTL register
245  */
246 static void mmc_reset_controller_fsm(struct hsmmc *mmc_base, u32 bit)
247 {
248         ulong start;
249
250         mmc_reg_out(&mmc_base->sysctl, bit, bit);
251
252         start = get_timer(0);
253         while ((readl(&mmc_base->sysctl) & bit) != 0) {
254                 if (get_timer(0) - start > MAX_RETRY_MS) {
255                         printf("%s: timedout waiting for sysctl %x to clear\n",
256                                 __func__, bit);
257                         return;
258                 }
259         }
260 }
261
262 static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
263                         struct mmc_data *data)
264 {
265         struct hsmmc *mmc_base = (struct hsmmc *)mmc->priv;
266         unsigned int flags, mmc_stat;
267         ulong start;
268
269         start = get_timer(0);
270         while ((readl(&mmc_base->pstate) & (DATI_MASK | CMDI_MASK)) != 0) {
271                 if (get_timer(0) - start > MAX_RETRY_MS) {
272                         printf("%s: timedout waiting on cmd inhibit to clear\n",
273                                         __func__);
274                         return TIMEOUT;
275                 }
276         }
277         writel(0xFFFFFFFF, &mmc_base->stat);
278         start = get_timer(0);
279         while (readl(&mmc_base->stat)) {
280                 if (get_timer(0) - start > MAX_RETRY_MS) {
281                         printf("%s: timedout waiting for STAT (%x) to clear\n",
282                                 __func__, readl(&mmc_base->stat));
283                         return TIMEOUT;
284                 }
285         }
286         /*
287          * CMDREG
288          * CMDIDX[13:8] : Command index
289          * DATAPRNT[5]  : Data Present Select
290          * ENCMDIDX[4]  : Command Index Check Enable
291          * ENCMDCRC[3]  : Command CRC Check Enable
292          * RSPTYP[1:0]
293          *      00 = No Response
294          *      01 = Length 136
295          *      10 = Length 48
296          *      11 = Length 48 Check busy after response
297          */
298         /* Delay added before checking the status of frq change
299          * retry not supported by mmc.c(core file)
300          */
301         if (cmd->cmdidx == SD_CMD_APP_SEND_SCR)
302                 udelay(50000); /* wait 50 ms */
303
304         if (!(cmd->resp_type & MMC_RSP_PRESENT))
305                 flags = 0;
306         else if (cmd->resp_type & MMC_RSP_136)
307                 flags = RSP_TYPE_LGHT136 | CICE_NOCHECK;
308         else if (cmd->resp_type & MMC_RSP_BUSY)
309                 flags = RSP_TYPE_LGHT48B;
310         else
311                 flags = RSP_TYPE_LGHT48;
312
313         /* enable default flags */
314         flags = flags | (CMD_TYPE_NORMAL | CICE_NOCHECK | CCCE_NOCHECK |
315                         MSBS_SGLEBLK | ACEN_DISABLE | BCE_DISABLE | DE_DISABLE);
316
317         if (cmd->resp_type & MMC_RSP_CRC)
318                 flags |= CCCE_CHECK;
319         if (cmd->resp_type & MMC_RSP_OPCODE)
320                 flags |= CICE_CHECK;
321
322         if (data) {
323                 if ((cmd->cmdidx == MMC_CMD_READ_MULTIPLE_BLOCK) ||
324                          (cmd->cmdidx == MMC_CMD_WRITE_MULTIPLE_BLOCK)) {
325                         flags |= (MSBS_MULTIBLK | BCE_ENABLE);
326                         data->blocksize = 512;
327                         writel(data->blocksize | (data->blocks << 16),
328                                                         &mmc_base->blk);
329                 } else
330                         writel(data->blocksize | NBLK_STPCNT, &mmc_base->blk);
331
332                 if (data->flags & MMC_DATA_READ)
333                         flags |= (DP_DATA | DDIR_READ);
334                 else
335                         flags |= (DP_DATA | DDIR_WRITE);
336         }
337
338         writel(cmd->cmdarg, &mmc_base->arg);
339         writel((cmd->cmdidx << 24) | flags, &mmc_base->cmd);
340
341         start = get_timer(0);
342         do {
343                 mmc_stat = readl(&mmc_base->stat);
344                 if (get_timer(0) - start > MAX_RETRY_MS) {
345                         printf("%s : timeout: No status update\n", __func__);
346                         return TIMEOUT;
347                 }
348         } while (!mmc_stat);
349
350         if ((mmc_stat & IE_CTO) != 0) {
351                 mmc_reset_controller_fsm(mmc_base, SYSCTL_SRC);
352                 return TIMEOUT;
353         } else if ((mmc_stat & ERRI_MASK) != 0)
354                 return -1;
355
356         if (mmc_stat & CC_MASK) {
357                 writel(CC_MASK, &mmc_base->stat);
358                 if (cmd->resp_type & MMC_RSP_PRESENT) {
359                         if (cmd->resp_type & MMC_RSP_136) {
360                                 /* response type 2 */
361                                 cmd->response[3] = readl(&mmc_base->rsp10);
362                                 cmd->response[2] = readl(&mmc_base->rsp32);
363                                 cmd->response[1] = readl(&mmc_base->rsp54);
364                                 cmd->response[0] = readl(&mmc_base->rsp76);
365                         } else
366                                 /* response types 1, 1b, 3, 4, 5, 6 */
367                                 cmd->response[0] = readl(&mmc_base->rsp10);
368                 }
369         }
370
371         if (data && (data->flags & MMC_DATA_READ)) {
372                 mmc_read_data(mmc_base, data->dest,
373                                 data->blocksize * data->blocks);
374         } else if (data && (data->flags & MMC_DATA_WRITE)) {
375                 mmc_write_data(mmc_base, data->src,
376                                 data->blocksize * data->blocks);
377         }
378         return 0;
379 }
380
381 static int mmc_read_data(struct hsmmc *mmc_base, char *buf, unsigned int size)
382 {
383         unsigned int *output_buf = (unsigned int *)buf;
384         unsigned int mmc_stat;
385         unsigned int count;
386
387         /*
388          * Start Polled Read
389          */
390         count = (size > MMCSD_SECTOR_SIZE) ? MMCSD_SECTOR_SIZE : size;
391         count /= 4;
392
393         while (size) {
394                 ulong start = get_timer(0);
395                 do {
396                         mmc_stat = readl(&mmc_base->stat);
397                         if (get_timer(0) - start > MAX_RETRY_MS) {
398                                 printf("%s: timedout waiting for status!\n",
399                                                 __func__);
400                                 return TIMEOUT;
401                         }
402                 } while (mmc_stat == 0);
403
404                 if ((mmc_stat & (IE_DTO | IE_DCRC | IE_DEB)) != 0)
405                         mmc_reset_controller_fsm(mmc_base, SYSCTL_SRD);
406
407                 if ((mmc_stat & ERRI_MASK) != 0)
408                         return 1;
409
410                 if (mmc_stat & BRR_MASK) {
411                         unsigned int k;
412
413                         writel(readl(&mmc_base->stat) | BRR_MASK,
414                                 &mmc_base->stat);
415                         for (k = 0; k < count; k++) {
416                                 *output_buf = readl(&mmc_base->data);
417                                 output_buf++;
418                         }
419                         size -= (count*4);
420                 }
421
422                 if (mmc_stat & BWR_MASK)
423                         writel(readl(&mmc_base->stat) | BWR_MASK,
424                                 &mmc_base->stat);
425
426                 if (mmc_stat & TC_MASK) {
427                         writel(readl(&mmc_base->stat) | TC_MASK,
428                                 &mmc_base->stat);
429                         break;
430                 }
431         }
432         return 0;
433 }
434
435 static int mmc_write_data(struct hsmmc *mmc_base, const char *buf,
436                                 unsigned int size)
437 {
438         unsigned int *input_buf = (unsigned int *)buf;
439         unsigned int mmc_stat;
440         unsigned int count;
441
442         /*
443          * Start Polled Read
444          */
445         count = (size > MMCSD_SECTOR_SIZE) ? MMCSD_SECTOR_SIZE : size;
446         count /= 4;
447
448         while (size) {
449                 ulong start = get_timer(0);
450                 do {
451                         mmc_stat = readl(&mmc_base->stat);
452                         if (get_timer(0) - start > MAX_RETRY_MS) {
453                                 printf("%s: timedout waiting for status!\n",
454                                                 __func__);
455                                 return TIMEOUT;
456                         }
457                 } while (mmc_stat == 0);
458
459                 if ((mmc_stat & (IE_DTO | IE_DCRC | IE_DEB)) != 0)
460                         mmc_reset_controller_fsm(mmc_base, SYSCTL_SRD);
461
462                 if ((mmc_stat & ERRI_MASK) != 0)
463                         return 1;
464
465                 if (mmc_stat & BWR_MASK) {
466                         unsigned int k;
467
468                         writel(readl(&mmc_base->stat) | BWR_MASK,
469                                         &mmc_base->stat);
470                         for (k = 0; k < count; k++) {
471                                 writel(*input_buf, &mmc_base->data);
472                                 input_buf++;
473                         }
474                         size -= (count*4);
475                 }
476
477                 if (mmc_stat & BRR_MASK)
478                         writel(readl(&mmc_base->stat) | BRR_MASK,
479                                 &mmc_base->stat);
480
481                 if (mmc_stat & TC_MASK) {
482                         writel(readl(&mmc_base->stat) | TC_MASK,
483                                 &mmc_base->stat);
484                         break;
485                 }
486         }
487         return 0;
488 }
489
490 static void mmc_set_ios(struct mmc *mmc)
491 {
492         struct hsmmc *mmc_base = (struct hsmmc *)mmc->priv;
493         unsigned int dsor = 0;
494         ulong start;
495
496         /* configue bus width */
497         switch (mmc->bus_width) {
498         case 8:
499                 writel(readl(&mmc_base->con) | DTW_8_BITMODE,
500                         &mmc_base->con);
501                 break;
502
503         case 4:
504                 writel(readl(&mmc_base->con) & ~DTW_8_BITMODE,
505                         &mmc_base->con);
506                 writel(readl(&mmc_base->hctl) | DTW_4_BITMODE,
507                         &mmc_base->hctl);
508                 break;
509
510         case 1:
511         default:
512                 writel(readl(&mmc_base->con) & ~DTW_8_BITMODE,
513                         &mmc_base->con);
514                 writel(readl(&mmc_base->hctl) & ~DTW_4_BITMODE,
515                         &mmc_base->hctl);
516                 break;
517         }
518
519         /* configure clock with 96Mhz system clock.
520          */
521         if (mmc->clock != 0) {
522                 dsor = (MMC_CLOCK_REFERENCE * 1000000 / mmc->clock);
523                 if ((MMC_CLOCK_REFERENCE * 1000000) / dsor > mmc->clock)
524                         dsor++;
525         }
526
527         mmc_reg_out(&mmc_base->sysctl, (ICE_MASK | DTO_MASK | CEN_MASK),
528                                 (ICE_STOP | DTO_15THDTO | CEN_DISABLE));
529
530         mmc_reg_out(&mmc_base->sysctl, ICE_MASK | CLKD_MASK,
531                                 (dsor << CLKD_OFFSET) | ICE_OSCILLATE);
532
533         start = get_timer(0);
534         while ((readl(&mmc_base->sysctl) & ICS_MASK) == ICS_NOTREADY) {
535                 if (get_timer(0) - start > MAX_RETRY_MS) {
536                         printf("%s: timedout waiting for ics!\n", __func__);
537                         return;
538                 }
539         }
540         writel(readl(&mmc_base->sysctl) | CEN_ENABLE, &mmc_base->sysctl);
541 }
542
543 int omap_mmc_init(int dev_index, uint host_caps_mask, uint f_max)
544 {
545         struct mmc *mmc;
546
547         mmc = &hsmmc_dev[dev_index];
548
549         sprintf(mmc->name, "OMAP SD/MMC");
550         mmc->send_cmd = mmc_send_cmd;
551         mmc->set_ios = mmc_set_ios;
552         mmc->init = mmc_init_setup;
553         mmc->getcd = NULL;
554
555         switch (dev_index) {
556         case 0:
557                 mmc->priv = (struct hsmmc *)OMAP_HSMMC1_BASE;
558                 break;
559 #ifdef OMAP_HSMMC2_BASE
560         case 1:
561                 mmc->priv = (struct hsmmc *)OMAP_HSMMC2_BASE;
562                 break;
563 #endif
564 #ifdef OMAP_HSMMC3_BASE
565         case 2:
566                 mmc->priv = (struct hsmmc *)OMAP_HSMMC3_BASE;
567                 break;
568 #endif
569         default:
570                 mmc->priv = (struct hsmmc *)OMAP_HSMMC1_BASE;
571                 return 1;
572         }
573         mmc->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195;
574         mmc->host_caps = (MMC_MODE_4BIT | MMC_MODE_HS_52MHz | MMC_MODE_HS |
575                                 MMC_MODE_HC) & ~host_caps_mask;
576
577         mmc->f_min = 400000;
578
579         if (f_max != 0)
580                 mmc->f_max = f_max;
581         else {
582                 if (mmc->host_caps & MMC_MODE_HS) {
583                         if (mmc->host_caps & MMC_MODE_HS_52MHz)
584                                 mmc->f_max = 52000000;
585                         else
586                                 mmc->f_max = 26000000;
587                 } else
588                         mmc->f_max = 20000000;
589         }
590
591         mmc->b_max = 0;
592
593 #if defined(CONFIG_OMAP34XX)
594         /*
595          * Silicon revs 2.1 and older do not support multiblock transfers.
596          */
597         if ((get_cpu_family() == CPU_OMAP34XX) && (get_cpu_rev() <= CPU_3XX_ES21))
598                 mmc->b_max = 1;
599 #endif
600
601         mmc_register(mmc);
602
603         return 0;
604 }