>From 24a7a1fe58d4cbc49dde56adb442c97cbbaf690b Mon Sep 17 00:00:00 2001
From: Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx>
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 <chuanxiao.dong@xxxxxxxxx>
---
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 majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
