power: reset: Add Axxia system reset driver

Add Axxia (AXM55xx) SoC system reset driver. This driver handles only system
reboot (and not power-off).

Signed-off-by: Anders Berg <anders.berg@lsi.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/Documentation/devicetree/bindings/power_supply/axxia-reset.txt b/Documentation/devicetree/bindings/power_supply/axxia-reset.txt
new file mode 100644 (file)
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 (file)
--- 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 (file)
--- 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 (file)
index 0000000..3b1f8d6
--- /dev/null
+++ b/drivers/power/reset/axxia-reset.c
@@ -0,0 +1,88 @@
+/*
+ * 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/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/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;
+
+       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);
+       }
+
+       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);