>From 24a7a1fe58d4cbc49dde56adb442c97cbbaf690b Mon Sep 17 00:00:00 2001 From: Chuanxiao Dong <[email protected]> Date: Thu, 18 Nov 2010 10:34:42 +0800 Subject: [PATCH 2/2] mmc: implemented hardware reset callback for sdhci layer
The hardware reset callback in sdhci layer cannot really do a reset for eMMC card. It need the real hardware controller to trigger a RST_n signal to do so. Different sdhci host controller need use reset_emmc callback to implement the RST_n signal. Signed-off-by: Chuanxiao Dong <[email protected]> --- drivers/mmc/host/sdhci.c | 23 +++++++++++++++++++++++ drivers/mmc/host/sdhci.h | 10 ++++++++++ 2 files changed, 33 insertions(+), 0 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 154cbf8..a05b87c 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1266,11 +1266,34 @@ out: spin_unlock_irqrestore(&host->lock, flags); } +/* + * HW reset callback for eMMC4.4 card + * In this function, HC will do the real HW reset + * for eMMC4.4 card + * + * RETURN VALUE: + * 0: reset emmc successfully + * -ENODEV: no valid hardware to do so + */ +static int sdhci_hardware_reset(struct mmc_host *mmc) +{ + int err = 1; + struct sdhci_host *host; + + host = mmc_priv(mmc); + + if (host->ops && host->ops->reset_emmc) + err = host->ops->reset_emmc(host); + + return err; +} + static const struct mmc_host_ops sdhci_ops = { .request = sdhci_request, .set_ios = sdhci_set_ios, .get_ro = sdhci_get_ro, .enable_sdio_irq = sdhci_enable_sdio_irq, + .hardware_reset = sdhci_hardware_reset, }; /*****************************************************************************\ diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index d52a716..24e49b0 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -218,6 +218,16 @@ struct sdhci_ops { void (*platform_send_init_74_clocks)(struct sdhci_host *host, u8 power_mode); unsigned int (*get_ro)(struct sdhci_host *host); + /* + * eMMC card reset callback. + * This callback can be used by sdhci layer to support eMMC4.4 + * hardware reset feature. In this function, should trigger a + * RST_n signal to reset eMMC card. + * return value: + * 0: successfully reset eMMC card. + * -ENODEV: no valid hardware to reset eMMC card. + */ + int (*reset_emmc)(struct sdhci_host *host); }; #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS -- 1.6.6.1 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
