[PATCH v2 2/6] power: reset: Add Allwinner A31 reset code

Maxime Ripard
2014-05-07T02:47:16Z

That code used to be in the machine code, but it's more fit here with other
restart hooks.

That will allow to cleanup the machine directory, while waiting for a proper
watchdog driver for the A31.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/power/reset/Kconfig | 7 ++++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/sun6i-reboot.c | 85 ++++++++++++++++++++++++++++++++++++++
3 files changed, 93 insertions(+)
create mode 100644 drivers/power/reset/sun6i-reboot.c

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index fa0e4e057b99..67aeb6ec08f9 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -43,6 +43,13 @@ config POWER_RESET_RESTART
Instead they restart, and u-boot holds the SoC until the
user presses a key. u-boot then boots into Linux.

+config POWER_RESET_SUN6I
+ bool "Allwinner A31 SoC reset driver"
+ depends on ARCH_SUNXI
+ depends on POWER_RESET
+ help
+ Reboot support for the Allwinner A31 SoCs.
+
config POWER_RESET_VEXPRESS
bool "ARM Versatile Express power-off and reset driver"
depends on ARM || ARM64
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index a5b4a77d1a41..950fdc011c7a 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -3,5 +3,6 @@ obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o
obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
+obj-$(CONFIG_POWER_RESET_SUN6I) += sun6i-reboot.o
obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o
obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o
diff --git a/drivers/power/reset/sun6i-reboot.c b/drivers/power/reset/sun6i-reboot.c
new file mode 100644
index 000000000000..af2cd7ff2fe8
--- /dev/null
+++ b/drivers/power/reset/sun6i-reboot.c
@@ -0,0 +1,85 @@
+/*
+ * Allwinner A31 SoCs reset code
+ *
+ * Copyright (C) 2012-2014 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+
+#include <asm/system_misc.h>
+
+#define SUN6I_WATCHDOG1_IRQ_REG 0x00
+#define SUN6I_WATCHDOG1_CTRL_REG 0x10
+#define SUN6I_WATCHDOG1_CTRL_RESTART BIT(0)
+#define SUN6I_WATCHDOG1_CONFIG_REG 0x14
+#define SUN6I_WATCHDOG1_CONFIG_RESTART BIT(0)
+#define SUN6I_WATCHDOG1_CONFIG_IRQ BIT(1)
+#define SUN6I_WATCHDOG1_MODE_REG 0x18
+#define SUN6I_WATCHDOG1_MODE_ENABLE BIT(0)
+
+static void __iomem *wdt_base;
+
+static void sun6i_wdt_restart(enum reboot_mode mode, const char *cmd)
+{
+ if (!wdt_base)
+ return;
+
+ /* Disable interrupts */
+ writel(0, wdt_base + SUN6I_WATCHDOG1_IRQ_REG);
+
+ /* We want to disable the IRQ and just reset the whole system */
+ writel(SUN6I_WATCHDOG1_CONFIG_RESTART,
+ wdt_base + SUN6I_WATCHDOG1_CONFIG_REG);
+
+ /* Enable timer. The default and lowest interval value is 0.5s */
+ writel(SUN6I_WATCHDOG1_MODE_ENABLE,
+ wdt_base + SUN6I_WATCHDOG1_MODE_REG);
+
+ /* Restart the watchdog. */
+ writel(SUN6I_WATCHDOG1_CTRL_RESTART,
+ wdt_base + SUN6I_WATCHDOG1_CTRL_REG);
+
+ while (1) {
+ mdelay(5);
+ writel(SUN6I_WATCHDOG1_MODE_ENABLE,
+ wdt_base + SUN6I_WATCHDOG1_MODE_REG);
+ }
+}
+
+static int sun6i_reboot_probe(struct platform_device *pdev)
+{
+ wdt_base = of_iomap(pdev->dev.of_node, 0);
+ if (!wdt_base) {
+ WARN(1, "failed to map watchdog base address");
+ return -ENODEV;
+ }
+
+ arm_pm_restart = sun6i_wdt_restart;
+
+ return 0;
+}
+
+static struct of_device_id sun6i_reboot_of_match[] = {
+ { .compatible = "allwinner,sun6i-a31-wdt" },
+ {}
+};
+
+static struct platform_driver sun6i_reboot_driver = {
+ .probe = sun6i_reboot_probe,
+ .driver = {
+ .name = "sun6i-reboot",
+ .of_match_table = sun6i_reboot_of_match,
+ },
+};
+module_platform_driver(sun6i_reboot_driver);
--
1.9.1