diff options
| author |   Simon Horman <horms@verge.net.au> | 2011-06-21 08:00:10 +0900 |
|---|---|---|
| committer |   Chris Ball <cjb@laptop.org> | 2011-07-20 17:20:57 -0400 |
| commit | 973ed3af1a570612771ed10dec6506c757767668 (patch) | |
| tree | db993034cacfcc3f3388c43d96459a123adc32a2 /drivers/mmc | |
| parent | mmc: tmio: Share register access functions (diff) | |
| download | linux-dev-973ed3af1a570612771ed10dec6506c757767668.tar.xz linux-dev-973ed3af1a570612771ed10dec6506c757767668.zip | |
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>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/host/sh_mobile_sdhi.c | 36 | ||||
| -rw-r--r-- | drivers/mmc/host/tmio_mmc.h | 5 |
2 files changed, 41 insertions, 0 deletions
diff --git a/drivers/mmc/host/sh_mobile_sdhi.c b/drivers/mmc/host/sh_mobile_sdhi.c index ce500f03df85..774f6439d7ce 100644 --- a/drivers/mmc/host/sh_mobile_sdhi.c +++ b/drivers/mmc/host/sh_mobile_sdhi.c @@ -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; diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h index 0c22df0f954d..211ef6e7a820 100644 --- a/drivers/mmc/host/tmio_mmc.h +++ b/drivers/mmc/host/tmio_mmc.h @@ -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)); } |