mmc: sdhci-acpi: add support for eMMC hardware reset for HID 80860F14

Add support for eMMC hardware reset for HID 80860F14.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 27 insertions, 1 deletions

diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
index 08a85ec33224..cdd4ce0d7c90 100644
--- a/drivers/mmc/host/sdhci-acpi.c
+++ b/drivers/mmc/host/sdhci-acpi.c
@@ -37,6 +37,7 @@
 #include <linux/acpi_gpio.h>
 #include <linux/pm.h>
 #include <linux/pm_runtime.h>
+#include <linux/delay.h>
 
 #include <linux/mmc/host.h>
 #include <linux/mmc/pm.h>
@@ -85,12 +86,37 @@ static int sdhci_acpi_enable_dma(struct sdhci_host *host)
         return 0;
 }
 
+static void sdhci_acpi_int_hw_reset(struct sdhci_host *host)
+{
+        u8 reg;
+
+        reg = sdhci_readb(host, SDHCI_POWER_CONTROL);
+        reg |= 0x10;
+        sdhci_writeb(host, reg, SDHCI_POWER_CONTROL);
+        /* For eMMC, minimum is 1us but give it 9us for good measure */
+        udelay(9);
+        reg &= ~0x10;
+        sdhci_writeb(host, reg, SDHCI_POWER_CONTROL);
+        /* For eMMC, minimum is 200us but give it 300us for good measure */
+        usleep_range(300, 1000);
+}
+
 static const struct sdhci_ops sdhci_acpi_ops_dflt = {
         .enable_dma = sdhci_acpi_enable_dma,
 };
 
+static const struct sdhci_ops sdhci_acpi_ops_int = {
+        .enable_dma = sdhci_acpi_enable_dma,
+        .hw_reset   = sdhci_acpi_int_hw_reset,
+};
+
+static const struct sdhci_acpi_chip sdhci_acpi_chip_int = {
+        .ops = &sdhci_acpi_ops_int,
+};
+
 static const struct sdhci_acpi_slot sdhci_acpi_slot_int_emmc = {
-        .caps    = MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE,
+        .chip    = &sdhci_acpi_chip_int,
+        .caps    = MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE | MMC_CAP_HW_RESET,
         .caps2   = MMC_CAP2_HC_ERASE_SZ,
         .flags   = SDHCI_ACPI_RUNTIME_PM,
 };