Merge tag 'keystone-reset-driver' of git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux-keystone into next/drivers

Merge "Keystone Reset driver for 3.16" from Santosh Shilimkar:

* tag 'keystone-reset-driver' of git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux-keystone:
  power: reset: keystone-reset: introduce keystone reset driver
  Documentation: dt: add bindings for keystone pll control controller
  Documentation: dt: add bindings for keystone reset driver

Signed-off-by: Olof Johansson <olof@lixom.net>

3 files changed, 175 insertions, 0 deletions

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 67aeb6ec08f9..736b91994249 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -64,3 +64,11 @@ config POWER_RESET_XGENE
         depends on POWER_RESET
         help
           Reboot support for the APM SoC X-Gene Eval boards.
+
+config POWER_RESET_KEYSTONE
+        bool "Keystone reset driver"
+        depends on ARCH_KEYSTONE
+        select MFD_SYSCON
+        help
+          Reboot support for the KEYSTONE SoCs.
+
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index 950fdc011c7a..618541b70207 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
 obj-$(CONFIG_POWER_RESET_SUN6I) += sun6i-reboot.o
 obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o
 obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o
+obj-$(CONFIG_POWER_RESET_KEYSTONE) += keystone-reset.o
diff --git a/drivers/power/reset/keystone-reset.c b/drivers/power/reset/keystone-reset.c
new file mode 100644
index 000000000000..408a18fd91cb
--- /dev/null
+++ b/drivers/power/reset/keystone-reset.c
@@ -0,0 +1,166 @@
+/*
+ * TI keystone reboot driver
+ *
+ * Copyright (C) 2014 Texas Instruments Incorporated. http://www.ti.com/
+ *
+ * Author: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+#include <asm/system_misc.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_platform.h>
+
+#define RSTYPE_RG                       0x0
+#define RSCTRL_RG                       0x4
+#define RSCFG_RG                        0x8
+#define RSISO_RG                        0xc
+
+#define RSCTRL_KEY_MASK                 0x0000ffff
+#define RSCTRL_RESET_MASK               BIT(16)
+#define RSCTRL_KEY                      0x5a69
+
+#define RSMUX_OMODE_MASK                0xe
+#define RSMUX_OMODE_RESET_ON            0xa
+#define RSMUX_OMODE_RESET_OFF           0x0
+#define RSMUX_LOCK_MASK                 0x1
+#define RSMUX_LOCK_SET                  0x1
+
+#define RSCFG_RSTYPE_SOFT               0x300f
+#define RSCFG_RSTYPE_HARD               0x0
+
+#define WDT_MUX_NUMBER                  0x4
+
+static int rspll_offset;
+static struct regmap *pllctrl_regs;
+
+/**
+ * rsctrl_enable_rspll_write - enable access to RSCTRL, RSCFG
+ * To be able to access to RSCTRL, RSCFG registers
+ * we have to write a key before
+ */
+static inline int rsctrl_enable_rspll_write(void)
+{
+        return regmap_update_bits(pllctrl_regs, rspll_offset + RSCTRL_RG,
+                                  RSCTRL_KEY_MASK, RSCTRL_KEY);
+}
+
+static void rsctrl_restart(enum reboot_mode mode, const char *cmd)
+{
+        /* enable write access to RSTCTRL */
+        rsctrl_enable_rspll_write();
+
+        /* reset the SOC */
+        regmap_update_bits(pllctrl_regs, rspll_offset + RSCTRL_RG,
+                           RSCTRL_RESET_MASK, 0);
+}
+
+static struct of_device_id rsctrl_of_match[] = {
+        {.compatible = "ti,keystone-reset", },
+        {},
+};
+
+static int rsctrl_probe(struct platform_device *pdev)
+{
+        int i;
+        int ret;
+        u32 val;
+        unsigned int rg;
+        u32 rsmux_offset;
+        struct regmap *devctrl_regs;
+        struct device *dev = &pdev->dev;
+        struct device_node *np = dev->of_node;
+
+        if (!np)
+                return -ENODEV;
+
+        /* get regmaps */
+        pllctrl_regs = syscon_regmap_lookup_by_phandle(np, "ti,syscon-pll");
+        if (IS_ERR(pllctrl_regs))
+                return PTR_ERR(pllctrl_regs);
+
+        devctrl_regs = syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
+        if (IS_ERR(devctrl_regs))
+                return PTR_ERR(devctrl_regs);
+
+        ret = of_property_read_u32_index(np, "ti,syscon-pll", 1, &rspll_offset);
+        if (ret) {
+                dev_err(dev, "couldn't read the reset pll offset!\n");
+                return -EINVAL;
+        }
+
+        ret = of_property_read_u32_index(np, "ti,syscon-dev", 1, &rsmux_offset);
+        if (ret) {
+                dev_err(dev, "couldn't read the rsmux offset!\n");
+                return -EINVAL;
+        }
+
+        /* set soft/hard reset */
+        val = of_property_read_bool(np, "ti,soft-reset");
+        val = val ? RSCFG_RSTYPE_SOFT : RSCFG_RSTYPE_HARD;
+
+        ret = rsctrl_enable_rspll_write();
+        if (ret)
+                return ret;
+
+        ret = regmap_write(pllctrl_regs, rspll_offset + RSCFG_RG, val);
+        if (ret)
+                return ret;
+
+        arm_pm_restart = rsctrl_restart;
+
+        /* disable a reset isolation for all module clocks */
+        ret = regmap_write(pllctrl_regs, rspll_offset + RSISO_RG, 0);
+        if (ret)
+                return ret;
+
+        /* enable a reset for watchdogs from wdt-list */
+        for (i = 0; i < WDT_MUX_NUMBER; i++) {
+                ret = of_property_read_u32_index(np, "ti,wdt-list", i, &val);
+                if (ret == -EOVERFLOW && !i) {
+                        dev_err(dev, "ti,wdt-list property has to contain at"
+                                "least one entry\n");
+                        return -EINVAL;
+                } else if (ret) {
+                        break;
+                }
+
+                if (val >= WDT_MUX_NUMBER) {
+                        dev_err(dev, "ti,wdt-list property can contain"
+                                "only numbers < 4\n");
+                        return -EINVAL;
+                }
+
+                rg = rsmux_offset + val * 4;
+
+                ret = regmap_update_bits(devctrl_regs, rg, RSMUX_OMODE_MASK,
+                                         RSMUX_OMODE_RESET_ON |
+                                         RSMUX_LOCK_SET);
+                if (ret)
+                        return ret;
+        }
+
+        return 0;
+}
+
+static struct platform_driver rsctrl_driver = {
+        .probe = rsctrl_probe,
+        .driver = {
+                .owner = THIS_MODULE,
+                .name = KBUILD_MODNAME,
+                .of_match_table = rsctrl_of_match,
+        },
+};
+module_platform_driver(rsctrl_driver);
+
+MODULE_AUTHOR("Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>");
+MODULE_DESCRIPTION("Texas Instruments keystone reset driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" KBUILD_MODNAME);