mmc: sdhi: Add write16_hook

Some controllers require waiting for the bus to become idle
before writing to some registers. I have implemented this
by adding a hook to sd_ctrl_write16() and implementing
a hook for SDHI which waits for the bus to become idle.

Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Simon Horman 2011-06-21 08:00:10 +09:00 committed by Chris Ball
parent a11862d338
commit 973ed3af1a
4 changed files with 50 additions and 0 deletions

View File

@ -26,6 +26,7 @@
#include <linux/mmc/sh_mobile_sdhi.h>
#include <linux/mfd/tmio.h>
#include <linux/sh_dma.h>
#include <linux/delay.h>
#include "tmio_mmc.h"
@ -55,6 +56,39 @@ static int sh_mobile_sdhi_get_cd(struct platform_device *pdev)
return -ENOSYS;
}
static int sh_mobile_sdhi_wait_idle(struct tmio_mmc_host *host)
{
int timeout = 1000;
while (--timeout && !(sd_ctrl_read16(host, CTL_STATUS2) & (1 << 13)))
udelay(1);
if (!timeout) {
dev_warn(host->pdata->dev, "timeout waiting for SD bus idle\n");
return -EBUSY;
}
return 0;
}
static int sh_mobile_sdhi_write16_hook(struct tmio_mmc_host *host, int addr)
{
switch (addr)
{
case CTL_SD_CMD:
case CTL_STOP_INTERNAL_ACTION:
case CTL_XFER_BLK_COUNT:
case CTL_SD_CARD_CLK_CTL:
case CTL_SD_XFER_LEN:
case CTL_SD_MEM_CARD_OPT:
case CTL_TRANSACTION_CTL:
case CTL_DMA_ENABLE:
return sh_mobile_sdhi_wait_idle(host);
}
return 0;
}
static int __devinit sh_mobile_sdhi_probe(struct platform_device *pdev)
{
struct sh_mobile_sdhi *priv;
@ -86,6 +120,8 @@ static int __devinit sh_mobile_sdhi_probe(struct platform_device *pdev)
mmc_data->hclk = clk_get_rate(priv->clk);
mmc_data->set_pwr = sh_mobile_sdhi_set_pwr;
mmc_data->get_cd = sh_mobile_sdhi_get_cd;
if (mmc_data->flags & TMIO_MMC_HAS_IDLE_WAIT)
mmc_data->write16_hook = sh_mobile_sdhi_write16_hook;
mmc_data->capabilities = MMC_CAP_MMC_HIGHSPEED;
if (p) {
mmc_data->flags = p->tmio_flags;

View File

@ -153,6 +153,11 @@ static inline u32 sd_ctrl_read32(struct tmio_mmc_host *host, int addr)
static inline void sd_ctrl_write16(struct tmio_mmc_host *host, int addr, u16 val)
{
/* If there is a hook and it returns non-zero then there
* is an error and the write should be skipped
*/
if (host->pdata->write16_hook && host->pdata->write16_hook(host, addr))
return;
writew(val, host->ctl + (addr << host->bus_shift));
}

View File

@ -68,6 +68,11 @@
* controller and report the event to the driver.
*/
#define TMIO_MMC_HAS_COLD_CD (1 << 3)
/*
* Some controllers require waiting for the SD bus to become
* idle before writing to some registers.
*/
#define TMIO_MMC_HAS_IDLE_WAIT (1 << 4)
int tmio_core_mmc_enable(void __iomem *cnf, int shift, unsigned long base);
int tmio_core_mmc_resume(void __iomem *cnf, int shift, unsigned long base);
@ -80,6 +85,8 @@ struct tmio_mmc_dma {
int alignment_shift;
};
struct tmio_mmc_host;
/*
* data for the MMC controller
*/
@ -94,6 +101,7 @@ struct tmio_mmc_data {
void (*set_pwr)(struct platform_device *host, int state);
void (*set_clk_div)(struct platform_device *host, int state);
int (*get_cd)(struct platform_device *host);
int (*write16_hook)(struct tmio_mmc_host *host, int addr);
};
static inline void tmio_mmc_cd_wakeup(struct tmio_mmc_data *pdata)

View File

@ -21,6 +21,7 @@
#define CTL_XFER_BLK_COUNT 0xa
#define CTL_RESPONSE 0x0c
#define CTL_STATUS 0x1c
#define CTL_STATUS2 0x1e
#define CTL_IRQ_MASK 0x20
#define CTL_SD_CARD_CLK_CTL 0x24
#define CTL_SD_XFER_LEN 0x26