[PATCH] mmc: meson-gx: add device reset

[Jerome Brunet]

Trigger the reset line of the mmc controller while probing, if available
The reset should be optional for now, at least until all related DT node
have the reset property

Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
---
 Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt | 2 ++
 drivers/mmc/host/meson-gx-mmc.c                            | 6 ++++++
 2 files changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt b/Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt
index 5add8d7d855f..ba434375e7f2 100644
--- a/Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt
+++ b/Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt
@@ -20,6 +20,7 @@ Required properties:
 	"clkin1" - Other parent clock of internal mux
   The driver has an internal mux clock which switches between clkin0 and clkin1 depending on the
   clock rate requested by the MMC core.
+- reset      : phandle of the internal reset line
 
 Example:
 
@@ -30,4 +31,5 @@ Example:
 		clocks = <&clkc CLKID_SD_EMMC_A>, <&xtal>, <&clkc CLKID_FCLK_DIV2>;
 		clock-names = "core", "clkin0", "clkin1";
 		pinctrl-0 = <&emmc_pins>;
+		resets = <&reset RESET_SD_EMMC_A>;
 	};
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 55bbd67177df..9d214622c8cf 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -35,6 +35,7 @@
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/regulator/consumer.h>
+#include <linux/reset.h>
 #include <linux/interrupt.h>
 #include <linux/bitfield.h>
 #include <linux/pinctrl/consumer.h>
@@ -1212,6 +1213,11 @@ static int meson_mmc_probe(struct platform_device *pdev)
 		goto free_host;
 	}
 
+	ret = device_reset_optional(&pdev->dev);
+	if (ret)
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "device reset failed: %d\n", ret);
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	host->regs = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(host->regs)) {
-- 
2.14.3