[PATCH v2 05/10] power/reset: Add reset driver support for nuc900

Wan Zongshun
2016-07-10T07:27:25Z

This driver is to add reset support for nuc900 series,
currently, it only supports nuc970 SoC reset.

Signed-off-by: Wan Zongshun <mcuos.com@gmail.com>
---
drivers/power/reset/Kconfig | 7 +++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/nuc900-reset.c | 93 ++++++++++++++++++++++++++++++++++++++
3 files changed, 101 insertions(+)
create mode 100644 drivers/power/reset/nuc900-reset.c

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 9bb2622..8c84892 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -94,6 +94,13 @@ config POWER_RESET_MSM
help
Power off and restart support for Qualcomm boards.

+config POWER_RESET_NUC900
+ bool "Nuc900 restart driver"
+ depends on ARCH_W90X900
+ help
+ Power off and restart support for Nuvoton NUC900 family of
+ reference boards.
+
config POWER_RESET_LTC2952
bool "LTC2952 PowerPath power-off driver"
depends on OF_GPIO
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index ab7aa86..d4df889 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o
obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o
obj-$(CONFIG_POWER_RESET_IMX) += imx-snvs-poweroff.o
obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o
+obj-$(CONFIG_POWER_RESET_NUC900) += nuc900-reset.o
obj-$(CONFIG_POWER_RESET_LTC2952) += ltc2952-poweroff.o
obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
diff --git a/drivers/power/reset/nuc900-reset.c b/drivers/power/reset/nuc900-reset.c
new file mode 100644
index 0000000..49986b7
--- /dev/null
+++ b/drivers/power/reset/nuc900-reset.c
@@ -0,0 +1,93 @@
+/*
+ * Copyright 2016 Wan Zongshun <mcuos.com@gmail.com>
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+
+#define REG_WRPRTR 0x1fc
+#define REG_AHBIPRST 0x060
+
+static struct regmap *syscon;
+
+static int nuc900_restart_handler(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ /*0:register protect enable*/
+ int write_protect = 0;
+
+ /*register protection disable*/
+ do {
+ regmap_read(syscon, REG_WRPRTR, &write_protect);
+
+ if (write_protect != 1) {
+ regmap_write(syscon, REG_WRPRTR, 0x59);
+ regmap_write(syscon, REG_WRPRTR, 0x16);
+ regmap_write(syscon, REG_WRPRTR, 0x88);
+ }
+
+ } while (write_protect != 1);
+
+ /*trigger reset*/
+ regmap_write(syscon, REG_AHBIPRST, 0x01);
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block nuc900_restart_nb = {
+ .notifier_call = nuc900_restart_handler,
+ .priority = 128,
+};
+
+static int nuc900_reset_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ int err;
+
+ syscon = syscon_regmap_lookup_by_phandle(dev->of_node, "syscon");
+ if (IS_ERR(syscon)) {
+ pr_err("%s: syscon lookup failed\n", dev->of_node->name);
+ return PTR_ERR(syscon);
+ }
+
+ err = register_restart_handler(&nuc900_restart_nb);
+ if (err)
+ dev_err(dev, "cannot register restart handler (err=%d)\n", err);
+
+ return err;
+}
+
+static const struct of_device_id of_nuc900_reset_match[] = {
+ { .compatible = "nuvoton,nuc900-reset", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_nuc900_reset_match);
+
+static struct platform_driver nuc900_reset_driver = {
+ .probe = nuc900_reset_probe,
+ .driver = {
+ .name = "nuc900-reset",
+ .of_match_table = of_match_ptr(of_nuc900_reset_match),
+ },
+};
+
+static int __init nuc900_reset_init(void)
+{
+ return platform_driver_register(&nuc900_reset_driver);
+}
+device_initcall(nuc900_reset_init);
--
2.7.4