linux/drivers/mmc/core/sd_ops.c
Mark Asselstine 6dd6bca3fb mmc: sd: clean up redundant memset
The clearing of mrq via a memset at the top of the for loop in
mmc_wait_for_app_cmd() is not required as mrq is not used and there is
another clearing of mrq just below.  We remove the first memset since if
the initial tests in the for loop fail the memset is not required.

Signed-off-by: Mark Asselstine <asselsm@gmail.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:39 -07:00

348 lines
6.9 KiB
C

/*
* linux/drivers/mmc/core/sd_ops.h
*
* Copyright 2006-2007 Pierre Ossman
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*/
#include <linux/types.h>
#include <linux/scatterlist.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sd.h>
#include "core.h"
#include "sd_ops.h"
static int mmc_app_cmd(struct mmc_host *host, struct mmc_card *card)
{
int err;
struct mmc_command cmd;
BUG_ON(!host);
BUG_ON(card && (card->host != host));
cmd.opcode = MMC_APP_CMD;
if (card) {
cmd.arg = card->rca << 16;
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
} else {
cmd.arg = 0;
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_BCR;
}
err = mmc_wait_for_cmd(host, &cmd, 0);
if (err)
return err;
/* Check that card supported application commands */
if (!mmc_host_is_spi(host) && !(cmd.resp[0] & R1_APP_CMD))
return -EOPNOTSUPP;
return 0;
}
/**
* mmc_wait_for_app_cmd - start an application command and wait for
completion
* @host: MMC host to start command
* @card: Card to send MMC_APP_CMD to
* @cmd: MMC command to start
* @retries: maximum number of retries
*
* Sends a MMC_APP_CMD, checks the card response, sends the command
* in the parameter and waits for it to complete. Return any error
* that occurred while the command was executing. Do not attempt to
* parse the response.
*/
int mmc_wait_for_app_cmd(struct mmc_host *host, struct mmc_card *card,
struct mmc_command *cmd, int retries)
{
struct mmc_request mrq;
int i, err;
BUG_ON(!cmd);
BUG_ON(retries < 0);
err = -EIO;
/*
* We have to resend MMC_APP_CMD for each attempt so
* we cannot use the retries field in mmc_command.
*/
for (i = 0;i <= retries;i++) {
err = mmc_app_cmd(host, card);
if (err) {
/* no point in retrying; no APP commands allowed */
if (mmc_host_is_spi(host)) {
if (cmd->resp[0] & R1_SPI_ILLEGAL_COMMAND)
break;
}
continue;
}
memset(&mrq, 0, sizeof(struct mmc_request));
memset(cmd->resp, 0, sizeof(cmd->resp));
cmd->retries = 0;
mrq.cmd = cmd;
cmd->data = NULL;
mmc_wait_for_req(host, &mrq);
err = cmd->error;
if (!cmd->error)
break;
/* no point in retrying illegal APP commands */
if (mmc_host_is_spi(host)) {
if (cmd->resp[0] & R1_SPI_ILLEGAL_COMMAND)
break;
}
}
return err;
}
EXPORT_SYMBOL(mmc_wait_for_app_cmd);
int mmc_app_set_bus_width(struct mmc_card *card, int width)
{
int err;
struct mmc_command cmd;
BUG_ON(!card);
BUG_ON(!card->host);
memset(&cmd, 0, sizeof(struct mmc_command));
cmd.opcode = SD_APP_SET_BUS_WIDTH;
cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
switch (width) {
case MMC_BUS_WIDTH_1:
cmd.arg = SD_BUS_WIDTH_1;
break;
case MMC_BUS_WIDTH_4:
cmd.arg = SD_BUS_WIDTH_4;
break;
default:
return -EINVAL;
}
err = mmc_wait_for_app_cmd(card->host, card, &cmd, MMC_CMD_RETRIES);
if (err)
return err;
return 0;
}
int mmc_send_app_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
{
struct mmc_command cmd;
int i, err = 0;
BUG_ON(!host);
memset(&cmd, 0, sizeof(struct mmc_command));
cmd.opcode = SD_APP_OP_COND;
if (mmc_host_is_spi(host))
cmd.arg = ocr & (1 << 30); /* SPI only defines one bit */
else
cmd.arg = ocr;
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R3 | MMC_CMD_BCR;
for (i = 100; i; i--) {
err = mmc_wait_for_app_cmd(host, NULL, &cmd, MMC_CMD_RETRIES);
if (err)
break;
/* if we're just probing, do a single pass */
if (ocr == 0)
break;
/* otherwise wait until reset completes */
if (mmc_host_is_spi(host)) {
if (!(cmd.resp[0] & R1_SPI_IDLE))
break;
} else {
if (cmd.resp[0] & MMC_CARD_BUSY)
break;
}
err = -ETIMEDOUT;
mmc_delay(10);
}
if (rocr && !mmc_host_is_spi(host))
*rocr = cmd.resp[0];
return err;
}
int mmc_send_if_cond(struct mmc_host *host, u32 ocr)
{
struct mmc_command cmd;
int err;
static const u8 test_pattern = 0xAA;
u8 result_pattern;
/*
* To support SD 2.0 cards, we must always invoke SD_SEND_IF_COND
* before SD_APP_OP_COND. This command will harmlessly fail for
* SD 1.0 cards.
*/
cmd.opcode = SD_SEND_IF_COND;
cmd.arg = ((ocr & 0xFF8000) != 0) << 8 | test_pattern;
cmd.flags = MMC_RSP_SPI_R7 | MMC_RSP_R7 | MMC_CMD_BCR;
err = mmc_wait_for_cmd(host, &cmd, 0);
if (err)
return err;
if (mmc_host_is_spi(host))
result_pattern = cmd.resp[1] & 0xFF;
else
result_pattern = cmd.resp[0] & 0xFF;
if (result_pattern != test_pattern)
return -EIO;
return 0;
}
int mmc_send_relative_addr(struct mmc_host *host, unsigned int *rca)
{
int err;
struct mmc_command cmd;
BUG_ON(!host);
BUG_ON(!rca);
memset(&cmd, 0, sizeof(struct mmc_command));
cmd.opcode = SD_SEND_RELATIVE_ADDR;
cmd.arg = 0;
cmd.flags = MMC_RSP_R6 | MMC_CMD_BCR;
err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
if (err)
return err;
*rca = cmd.resp[0] >> 16;
return 0;
}
int mmc_app_send_scr(struct mmc_card *card, u32 *scr)
{
int err;
struct mmc_request mrq;
struct mmc_command cmd;
struct mmc_data data;
struct scatterlist sg;
BUG_ON(!card);
BUG_ON(!card->host);
BUG_ON(!scr);
/* NOTE: caller guarantees scr is heap-allocated */
err = mmc_app_cmd(card->host, card);
if (err)
return err;
memset(&mrq, 0, sizeof(struct mmc_request));
memset(&cmd, 0, sizeof(struct mmc_command));
memset(&data, 0, sizeof(struct mmc_data));
mrq.cmd = &cmd;
mrq.data = &data;
cmd.opcode = SD_APP_SEND_SCR;
cmd.arg = 0;
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
data.blksz = 8;
data.blocks = 1;
data.flags = MMC_DATA_READ;
data.sg = &sg;
data.sg_len = 1;
sg_init_one(&sg, scr, 8);
mmc_set_data_timeout(&data, card);
mmc_wait_for_req(card->host, &mrq);
if (cmd.error)
return cmd.error;
if (data.error)
return data.error;
scr[0] = be32_to_cpu(scr[0]);
scr[1] = be32_to_cpu(scr[1]);
return 0;
}
int mmc_sd_switch(struct mmc_card *card, int mode, int group,
u8 value, u8 *resp)
{
struct mmc_request mrq;
struct mmc_command cmd;
struct mmc_data data;
struct scatterlist sg;
BUG_ON(!card);
BUG_ON(!card->host);
/* NOTE: caller guarantees resp is heap-allocated */
mode = !!mode;
value &= 0xF;
memset(&mrq, 0, sizeof(struct mmc_request));
memset(&cmd, 0, sizeof(struct mmc_command));
memset(&data, 0, sizeof(struct mmc_data));
mrq.cmd = &cmd;
mrq.data = &data;
cmd.opcode = SD_SWITCH;
cmd.arg = mode << 31 | 0x00FFFFFF;
cmd.arg &= ~(0xF << (group * 4));
cmd.arg |= value << (group * 4);
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
data.blksz = 64;
data.blocks = 1;
data.flags = MMC_DATA_READ;
data.sg = &sg;
data.sg_len = 1;
sg_init_one(&sg, resp, 64);
mmc_set_data_timeout(&data, card);
mmc_wait_for_req(card->host, &mrq);
if (cmd.error)
return cmd.error;
if (data.error)
return data.error;
return 0;
}