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authorIvan Khoronzhuk <ivan.khoronzhuk@ti.com>2014-05-24 00:32:39 +0400
committerSantosh Shilimkar <santosh.shilimkar@ti.com>2014-05-27 17:46:40 +0400
commita3e01e8022932a1fbfbad72058967e5da78657e5 (patch)
treef9d9b9eacb6faa839cf1426bad4ecdf7ac998e81 /drivers/power
parentd30982b93a79aafa688e7df1f6948ad28bb94e89 (diff)
downloadlinux-a3e01e8022932a1fbfbad72058967e5da78657e5.tar.xz
power: reset: keystone-reset: introduce keystone reset driver
The keystone SoC can be rebooted in several ways. By external reset pin, by soft and by watchdogs. To allow keystone SoC reset if watchdog is triggered we have to enable it in reset mux configuration register regarding of watchdog configuration. Also we need to set soft/hard reset we are going to use. So add keystone reset driver to handle all this stuff. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Diffstat (limited to 'drivers/power')
-rw-r--r--drivers/power/reset/Kconfig8
-rw-r--r--drivers/power/reset/Makefile1
-rw-r--r--drivers/power/reset/keystone-reset.c166
3 files changed, 175 insertions, 0 deletions
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index fa0e4e057b99..d095e5b1c505 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -57,3 +57,11 @@ 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 a5b4a77d1a41..802a420741ab 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -5,3 +5,4 @@ obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.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);