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author | Philip Rakity <prakity@marvell.com> | 2010-11-19 16:48:39 -0500 |
---|---|---|
committer | Chris Ball <cjb@laptop.org> | 2010-11-22 15:12:04 -0500 |
commit | 15ec44611904be0dcc97b84c29fbf964e5e2b36f (patch) | |
tree | d64384c6bf47beee40172419a29b09c2943e964e /drivers/mmc | |
parent | ed919b0125b26dcc052e44836f66e7e1f5c49c7e (diff) | |
download | kernel_samsung_smdk4412-15ec44611904be0dcc97b84c29fbf964e5e2b36f.zip kernel_samsung_smdk4412-15ec44611904be0dcc97b84c29fbf964e5e2b36f.tar.gz kernel_samsung_smdk4412-15ec44611904be0dcc97b84c29fbf964e5e2b36f.tar.bz2 |
mmc: sdhci: 8-bit bus width changes
We now:
* check for a v3 controller before setting 8-bit bus width
* offer a callback for platform code to switch to 8-bit mode, which
allows non-v3 controllers to support it
* rely on mmc->caps |= MMC_CAP_8_BIT_DATA; in platform code to specify
that the board designers have indeed brought out all the pins for
8-bit to the slot.
We were previously relying only on whether the *controller* supported
8-bit, which doesn't tell us anything about the pin configuration in
the board design.
This fixes the MMC card regression reported by Maxim Levitsky here:
http://thread.gmane.org/gmane.linux.kernel.mmc/4336
by no longer assuming that 8-bit works by default.
Signed-off-by: Philip Rakity <prakity@marvell.com>
Tested-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r-- | drivers/mmc/host/sdhci-pxa.c | 4 | ||||
-rw-r--r-- | drivers/mmc/host/sdhci.c | 44 | ||||
-rw-r--r-- | drivers/mmc/host/sdhci.h | 5 |
3 files changed, 41 insertions, 12 deletions
diff --git a/drivers/mmc/host/sdhci-pxa.c b/drivers/mmc/host/sdhci-pxa.c index fc406ac..5a61208 100644 --- a/drivers/mmc/host/sdhci-pxa.c +++ b/drivers/mmc/host/sdhci-pxa.c @@ -141,6 +141,10 @@ static int __devinit sdhci_pxa_probe(struct platform_device *pdev) if (pdata->quirks) host->quirks |= pdata->quirks; + /* If slot design supports 8 bit data, indicate this to MMC. */ + if (pdata->flags & PXA_FLAG_SD_8_BIT_CAPABLE_SLOT) + host->mmc->caps |= MMC_CAP_8_BIT_DATA; + ret = sdhci_add_host(host); if (ret) { dev_err(&pdev->dev, "failed to add host\n"); diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 154cbf8..a25db42 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1185,17 +1185,31 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) if (host->ops->platform_send_init_74_clocks) host->ops->platform_send_init_74_clocks(host, ios->power_mode); - ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL); - - if (ios->bus_width == MMC_BUS_WIDTH_8) - ctrl |= SDHCI_CTRL_8BITBUS; - else - ctrl &= ~SDHCI_CTRL_8BITBUS; + /* + * If your platform has 8-bit width support but is not a v3 controller, + * or if it requires special setup code, you should implement that in + * platform_8bit_width(). + */ + if (host->ops->platform_8bit_width) + host->ops->platform_8bit_width(host, ios->bus_width); + else { + ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL); + if (ios->bus_width == MMC_BUS_WIDTH_8) { + ctrl &= ~SDHCI_CTRL_4BITBUS; + if (host->version >= SDHCI_SPEC_300) + ctrl |= SDHCI_CTRL_8BITBUS; + } else { + if (host->version >= SDHCI_SPEC_300) + ctrl &= ~SDHCI_CTRL_8BITBUS; + if (ios->bus_width == MMC_BUS_WIDTH_4) + ctrl |= SDHCI_CTRL_4BITBUS; + else + ctrl &= ~SDHCI_CTRL_4BITBUS; + } + sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL); + } - if (ios->bus_width == MMC_BUS_WIDTH_4) - ctrl |= SDHCI_CTRL_4BITBUS; - else - ctrl &= ~SDHCI_CTRL_4BITBUS; + ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL); if ((ios->timing == MMC_TIMING_SD_HS || ios->timing == MMC_TIMING_MMC_HS) @@ -1855,11 +1869,19 @@ int sdhci_add_host(struct sdhci_host *host) mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_300; else mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_200; + mmc->f_max = host->max_clk; mmc->caps |= MMC_CAP_SDIO_IRQ; + /* + * A controller may support 8-bit width, but the board itself + * might not have the pins brought out. Boards that support + * 8-bit width must set "mmc->caps |= MMC_CAP_8_BIT_DATA;" in + * their platform code before calling sdhci_add_host(), and we + * won't assume 8-bit width for hosts without that CAP. + */ if (!(host->quirks & SDHCI_QUIRK_FORCE_1_BIT_DATA)) - mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA; + mmc->caps |= MMC_CAP_4_BIT_DATA; if (caps & SDHCI_CAN_DO_HISPD) mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED; diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index d52a716..e42d7f0 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -76,7 +76,7 @@ #define SDHCI_CTRL_ADMA1 0x08 #define SDHCI_CTRL_ADMA32 0x10 #define SDHCI_CTRL_ADMA64 0x18 -#define SDHCI_CTRL_8BITBUS 0x20 +#define SDHCI_CTRL_8BITBUS 0x20 #define SDHCI_POWER_CONTROL 0x29 #define SDHCI_POWER_ON 0x01 @@ -155,6 +155,7 @@ #define SDHCI_CLOCK_BASE_SHIFT 8 #define SDHCI_MAX_BLOCK_MASK 0x00030000 #define SDHCI_MAX_BLOCK_SHIFT 16 +#define SDHCI_CAN_DO_8BIT 0x00040000 #define SDHCI_CAN_DO_ADMA2 0x00080000 #define SDHCI_CAN_DO_ADMA1 0x00100000 #define SDHCI_CAN_DO_HISPD 0x00200000 @@ -215,6 +216,8 @@ struct sdhci_ops { unsigned int (*get_max_clock)(struct sdhci_host *host); unsigned int (*get_min_clock)(struct sdhci_host *host); unsigned int (*get_timeout_clock)(struct sdhci_host *host); + int (*platform_8bit_width)(struct sdhci_host *host, + int width); void (*platform_send_init_74_clocks)(struct sdhci_host *host, u8 power_mode); unsigned int (*get_ro)(struct sdhci_host *host); |