[PATCH v4 4/9] power: reset: Add AT91RM9200 reset driver

Alexandre Belloni
2015-03-05T15:50:39Z

AT91RM9200 uses the watchdog from the system timer to reset.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
drivers/power/reset/Kconfig | 7 ++++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/at91rm9200-reset.c | 72 ++++++++++++++++++++++++++++++++++
3 files changed, 80 insertions(+)
create mode 100644 drivers/power/reset/at91rm9200-reset.c

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 27f6646731b0..8d79e45ae754 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -30,6 +30,13 @@ config POWER_RESET_AT91_RESET
This driver supports restart for Atmel AT91SAM9 and SAMA5
SoCs

+config POWER_RESET_AT91RM9200_RESET
+ bool "Atmel AT91RM9200 reset driver"
+ depends on ARCH_AT91 && MFD_SYSCON
+ default SOC_AT91RM9200
+ help
+ This driver supports restart for Atmel AT91RM9200.
+
config POWER_RESET_AXXIA
bool "LSI Axxia reset driver"
depends on ARCH_AXXIA
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index 11de15bae52e..96e972bbb922 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -1,6 +1,7 @@
obj-$(CONFIG_POWER_RESET_AS3722) += as3722-poweroff.o
obj-$(CONFIG_POWER_RESET_AT91_POWEROFF) += at91-poweroff.o
obj-$(CONFIG_POWER_RESET_AT91_RESET) += at91-reset.o
+obj-$(CONFIG_POWER_RESET_AT91RM9200_RESET) += at91rm9200-reset.o
obj-$(CONFIG_POWER_RESET_AXXIA) += axxia-reset.o
obj-$(CONFIG_POWER_RESET_BRCMSTB) += brcmstb-reboot.o
obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
diff --git a/drivers/power/reset/at91rm9200-reset.c b/drivers/power/reset/at91rm9200-reset.c
new file mode 100644
index 000000000000..b739ac82b9c9
--- /dev/null
+++ b/drivers/power/reset/at91rm9200-reset.c
@@ -0,0 +1,72 @@
+/*
+ * Atmel AT91 RM9200 SoCs reset code
+ *
+ * Copyright (C) 2015 Atmel Corporation.
+ *
+ * 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/mfd/syscon.h>
+#include <linux/mfd/syscon/atmel-st.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+
+static struct regmap *regmap_st;
+
+static int at91rm9200_restart(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ /*
+ * Perform a hardware reset with the use of the Watchdog timer.
+ */
+ regmap_write(regmap_st, AT91_ST_WDMR,
+ AT91_ST_RSTEN | AT91_ST_EXTEN | 1);
+ regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
+
+ mdelay(2000);
+
+ pr_emerg("Unable to restart system\n");
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block at91rm9200_restart_nb = {
+ .notifier_call = at91rm9200_restart,
+ .priority = 192,
+};
+
+static int at91rm9200_reset_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+
+ regmap_st = syscon_node_to_regmap(np);
+ if (!regmap_st)
+ return -ENODEV;
+
+ return register_restart_handler(&at91rm9200_restart_nb);
+}
+
+static const struct of_device_id at91rm9200_reset_of_match[] = {
+ { .compatible = "atmel,at91rm9200-st" },
+ { /* sentinel */ }
+};
+
+static struct platform_driver at91rm9200_reset_driver = {
+ .probe = at91rm9200_reset_probe,
+ .driver = {
+ .name = "at91rm9200-reset",
+ .of_match_table = at91rm9200_reset_of_match,
+ },
+};
+module_platform_driver(at91rm9200_reset_driver);
+
+MODULE_ALIAS("platform:at91rm9200-reset");
+MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
+MODULE_DESCRIPTION("Atmel at91rm9200 System Timer Reset driver");
+MODULE_LICENSE("GPL v2");
--
2.1.0