ARM: Exynos: fix reboot hang on Odroid X2/U2/U3 with eMMC memory

Odroid X/X2/U2/U3 require special handling of SD4_nRESET_OUT line for eMMC
memory to perform complete reboot. This patch adds code for performing such
reset.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Change-id: I0dd05288da3d5e661772914cc853a1267609fc6d

diff --git a/arch/arm/boot/dts/exynos4412-odroid-common.dtsi b/arch/arm/boot/dts/exynos4412-odroid-common.dtsi
index 1600037..9eac03c 100644 (file)
--- a/arch/arm/boot/dts/exynos4412-odroid-common.dtsi
+++ b/arch/arm/boot/dts/exynos4412-odroid-common.dtsi
@@ -516,6 +516,11 @@
                vdd_pll-supply = <&ldo8_reg>;
                status = "okay";
        };
+
+       odroid_reboot {
+               compatible = "hardkernel,odroid-reboot";
+               reset-gpio = <&gpk1 2 0>;
+       };
 };
 
 &pinctrl_1 {

diff --git a/arch/arm/mach-exynos/Makefile b/arch/arm/mach-exynos/Makefile
index 0b539ea..9f6844c 100644 (file)
--- a/arch/arm/mach-exynos/Makefile
+++ b/arch/arm/mach-exynos/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_MACH_EXYNOS4_DT)         += mach-exynos4-dt.o
 obj-$(CONFIG_MACH_EXYNOS5_DT)          += mach-exynos5-dt.o
 
 obj-$(CONFIG_ARCH_EXYNOS4)             += sec-reboot.o
+obj-$(CONFIG_ARCH_EXYNOS4)             += odroid-reboot.o
 
 # device support
 

diff --git a/arch/arm/mach-exynos/odroid-reboot.c b/arch/arm/mach-exynos/odroid-reboot.c
new file mode 100644 (file)
index 0000000..a81a5cb
--- /dev/null
+++ b/arch/arm/mach-exynos/odroid-reboot.c
@@ -0,0 +1,96 @@
+#include <linux/delay.h>
+#include <linux/pm.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <asm/cacheflush.h>
+#include <asm/system.h>
+#include <mach/regs-pmu.h>
+#include <linux/gpio.h>
+#include "common.h"
+#include <linux/extcon.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+
+struct odroid_reboot_platform_data {
+       struct device *dev;
+       int power_gpio;
+};
+
+static struct odroid_reboot_platform_data *g_pdata;
+
+static void odroid_reboot(char str, const char *cmd)
+{
+       local_irq_disable();
+
+       writel(0x12345678, S5P_INFORM2);        /* Don't enter lpm mode */
+       writel(0x0, S5P_INFORM4);               /* Reset reboot count */
+
+        gpio_set_value(g_pdata->power_gpio, 0);
+        mdelay(150);
+        gpio_set_value(g_pdata->power_gpio, 1);
+
+       flush_cache_all();
+       outer_flush_all();
+
+       exynos4_restart(0, 0);
+
+       pr_emerg("%s: waiting for reboot\n", __func__);
+       while (1)
+               ;
+}
+
+static struct odroid_reboot_platform_data *odroid_reboot_parse_dt(struct device *dev)
+{
+       struct device_node *np = dev->of_node;
+       struct odroid_reboot_platform_data *pdata;
+
+       pdata = devm_kzalloc(dev, sizeof(struct odroid_reboot_platform_data),
+                            GFP_KERNEL);
+       if (!pdata)
+               return NULL;
+
+       pdata->power_gpio = of_get_named_gpio(np, "reset-gpio", 0);
+       if (!gpio_is_valid(pdata->power_gpio)) {
+               dev_err(dev, "invalied power-gpio\n");
+               return NULL;
+       }
+       devm_gpio_request(dev, pdata->power_gpio, "reset-gpio");
+
+       return pdata;
+}
+
+static int odroid_reboot_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+
+       if (pdev->dev.of_node)
+               g_pdata = odroid_reboot_parse_dt(dev);
+
+       if (!g_pdata) {
+               dev_err(&pdev->dev, "failed to get platform data\n");
+               return -EINVAL;
+       }
+
+       g_pdata->dev = &pdev->dev;
+
+       /* Set machine specific functions */
+       arm_pm_restart = odroid_reboot;
+
+       return 0;
+}
+
+static struct of_device_id odroid_reboot_of_match[] = {
+       { .compatible = "hardkernel,odroid-reboot", },
+       { },
+};
+
+static struct platform_driver odroid_reboot_driver = {
+       .probe          = odroid_reboot_probe,
+       .driver         = {
+               .name   = "odroid-reboot",
+               .owner  = THIS_MODULE,
+               .of_match_table = of_match_ptr(odroid_reboot_of_match),
+       }
+};
+
+module_platform_driver(odroid_reboot_driver);