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path: root/drivers/power/reset/sun6i-reboot.c
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Diffstat (limited to 'drivers/power/reset/sun6i-reboot.c')
-rw-r--r--drivers/power/reset/sun6i-reboot.c85
1 files changed, 85 insertions, 0 deletions
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);