[PATCH v3 5/6] power: reset: Add Axxia system reset driver
From: Anders Berg
Date: Wed May 14 2014 - 14:38:49 EST
From: Anders Berg <anders.berg@xxxxxxx>
Add Axxia (AXM55xx) SoC system reset driver. This driver handles only system
reboot (and not power-off).
Signed-off-by: Anders Berg <anders.berg@xxxxxxx>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
.../bindings/power_supply/axxia-reset.txt | 20 +++++
drivers/power/reset/Kconfig | 8 ++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/axxia-reset.c | 97 ++++++++++++++++++++++
4 files changed, 126 insertions(+)
create mode 100644 Documentation/devicetree/bindings/power_supply/axxia-reset.txt
create mode 100644 drivers/power/reset/axxia-reset.c
diff --git a/Documentation/devicetree/bindings/power_supply/axxia-reset.txt b/Documentation/devicetree/bindings/power_supply/axxia-reset.txt
new file mode 100644
index 0000000..47e720d
--- /dev/null
+++ b/Documentation/devicetree/bindings/power_supply/axxia-reset.txt
@@ -0,0 +1,20 @@
+Axxia Restart Driver
+
+This driver can do reset of the Axxia SoC. It uses the registers in the syscon
+block to initiate a chip reset.
+
+Required Properties:
+ -compatible: "lsi,axm55xx-reset"
+ -syscon: phandle to the syscon node.
+
+Example:
+
+ syscon: syscon@2010030000 {
+ compatible = "lsi,axxia-syscon", "syscon";
+ reg = <0x20 0x10030000 0 0x2000>;
+ };
+
+ reset: reset@2010031000 {
+ compatible = "lsi,axm55xx-reset";
+ syscon = <&syscon>;
+ };
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index fa0e4e0..49b46e6 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -12,6 +12,14 @@ config POWER_RESET_AS3722
help
This driver supports turning off board via a ams AS3722 power-off.
+config POWER_RESET_AXXIA
+ bool "LSI Axxia reset driver"
+ depends on POWER_RESET && ARCH_AXXIA
+ help
+ This driver supports restart for Axxia SoC.
+
+ Say Y if you have an Axxia family SoC.
+
config POWER_RESET_GPIO
bool "GPIO power-off driver"
depends on OF_GPIO && POWER_RESET
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index a5b4a77..16c0516 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -1,4 +1,5 @@
obj-$(CONFIG_POWER_RESET_AS3722) += as3722-poweroff.o
+obj-$(CONFIG_POWER_RESET_AXXIA) += axxia-reset.o
obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o
obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
diff --git a/drivers/power/reset/axxia-reset.c b/drivers/power/reset/axxia-reset.c
new file mode 100644
index 0000000..a16eb50
--- /dev/null
+++ b/drivers/power/reset/axxia-reset.c
@@ -0,0 +1,97 @@
+/*
+ * Reset driver for Axxia devices
+ *
+ * Copyright (C) 2014 LSI
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+
+#include <asm/system_misc.h>
+
+
+#define SC_CRIT_WRITE_KEY 0x1000
+#define SC_LATCH_ON_RESET 0x1004
+#define SC_RESET_CONTROL 0x1008
+#define RSTCTL_RST_ZERO (1<<3)
+#define RSTCTL_RST_FAB (1<<2)
+#define RSTCTL_RST_CHIP (1<<1)
+#define RSTCTL_RST_SYS (1<<0)
+#define SC_EFUSE_INT_STATUS 0x180c
+#define EFUSE_READ_DONE (1<<31)
+
+static struct regmap *syscon;
+
+static void do_axxia_restart(enum reboot_mode reboot_mode, const char *cmd)
+{
+ /* Access Key (0xab) */
+ regmap_write(syscon, SC_CRIT_WRITE_KEY, 0xab);
+ /* Select internal boot from 0xffff0000 */
+ regmap_write(syscon, SC_LATCH_ON_RESET, 0x00000040);
+ /* Assert ResetReadDone (to avoid hanging in boot ROM) */
+ regmap_write(syscon, SC_EFUSE_INT_STATUS, EFUSE_READ_DONE);
+ /* Assert chip reset */
+ regmap_update_bits(syscon, SC_RESET_CONTROL,
+ RSTCTL_RST_CHIP, RSTCTL_RST_CHIP);
+}
+
+static int axxia_reset_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *dev_np = dev->of_node;
+ struct device_node *syscon_np;
+
+ syscon_np = of_parse_phandle(dev_np, "syscon", 0);
+ if (!syscon_np) {
+ pr_err("%s: no handle to syscon node\n", dev_np->name);
+ return -ENODEV;
+ }
+
+ syscon = syscon_node_to_regmap(syscon_np);
+ if (IS_ERR(syscon)) {
+ pr_err("%s: could not locate syscon regmap\n", dev_np->name);
+ return PTR_ERR(syscon);
+ }
+
+ arm_pm_restart = do_axxia_restart;
+
+ return 0;
+}
+
+static const struct of_device_id of_axxia_reset_match[] = {
+ { .compatible = "lsi,axm55xx-reset", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, of_axxia_reset_match);
+
+static struct platform_driver axxia_reset_driver = {
+ .probe = axxia_reset_probe,
+ .driver = {
+ .name = "axxia-reset",
+ .of_match_table = of_match_ptr(of_axxia_reset_match),
+ },
+};
+
+static int __init axxia_reset_init(void)
+{
+ return platform_driver_register(&axxia_reset_driver);
+}
+device_initcall(axxia_reset_init);
--
1.8.3.2
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