[PATCH v1 3/3] watchdog: zx2967: add watchdog controller driver for ZTE's zx2967 family

Baoyou Xie
2017-01-16T04:20:38Z

This patch adds watchdog controller driver for ZTE's zx2967 family.

Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
---
drivers/watchdog/Kconfig | 10 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/zx2967_wdt.c | 405 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 416 insertions(+)
create mode 100644 drivers/watchdog/zx2967_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 3eb58cb..79027da 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -714,6 +714,16 @@ config ASPEED_WATCHDOG
To compile this driver as a module, choose M here: the
module will be called aspeed_wdt.

+config ZX2967_WATCHDOG
+ tristate "ZTE zx2967 SoCs watchdog support"
+ depends on ARCH_ZX
+ select WATCHDOG_CORE
+ help
+ Say Y here to include support for the watchdog timer
+ in ZTE zx2967 SoCs.
+ To compile this driver as a module, choose M here: the
+ module will be called zx2967_wdt.
+
# AVR32 Architecture

config AT32AP700X_WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index caa9f4a..ea08925 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -82,6 +82,7 @@ obj-$(CONFIG_BCM7038_WDT) += bcm7038_wdt.o
obj-$(CONFIG_ATLAS7_WATCHDOG) += atlas7_wdt.o
obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o
obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o
+obj-$(CONFIG_ZX2967_WATCHDOG) += zx2967_wdt.o

# AVR32 Architecture
obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
diff --git a/drivers/watchdog/zx2967_wdt.c b/drivers/watchdog/zx2967_wdt.c
new file mode 100644
index 0000000..8791dd2
--- /dev/null
+++ b/drivers/watchdog/zx2967_wdt.c
@@ -0,0 +1,405 @@
+/*
+ * watchdog driver for ZTE's zx2967 family
+ *
+ * Copyright (C) 2017 ZTE Ltd.
+ *
+ * Author: Baoyou Xie <baoyou.xie@linaro.org>
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/reset.h>
+#include <linux/watchdog.h>
+
+#define ZX2967_WDT_CFG_REG 0x4
+#define ZX2967_WDT_LOAD_REG 0x8
+#define ZX2967_WDT_REFRESH_REG 0x18
+#define ZX2967_WDT_START_REG 0x1c
+
+#define ZX2967_WDT_REFRESH_MASK 0x3f
+
+#define ZX2967_WDT_CFG_DIV(n) ((((n)&0xff) - 1) << 8)
+#define ZX2967_WDT_START_EN 0x1
+
+#define ZX2967_WDT_WRITEKEY 0x12340000
+
+#define ZX2967_WDT_DIV_DEFAULT 16
+#define ZX2967_WDT_DEFAULT_TIMEOUT 32
+#define ZX2967_WDT_MIN_TIMEOUT 1
+#define ZX2967_WDT_MAX_TIMEOUT 500
+#define ZX2967_WDT_MAX_COUNT 0xffff
+
+#define ZX2967_WDT_FLAG_REBOOT_MON (1 << 0)
+
+#define ZX2967_RESET_MASK_REG 0xb0
+
+#define zx2967_wdt_write_reg(v, r) \
+ writel((v) | ZX2967_WDT_WRITEKEY, r)
+#define zx2967_wdt_read_reg(r) readl(r)
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static unsigned int timeout = ZX2967_WDT_DEFAULT_TIMEOUT;
+
+struct zx2967_wdt {
+ struct device *dev;
+ struct clk *clock;
+ void __iomem *reg_base;
+ unsigned int conf;
+ unsigned int load;
+ unsigned int flags;
+ spinlock_t lock;
+ struct watchdog_device wdt_device;
+ struct notifier_block restart_handler;
+ struct notifier_block reboot_handler;
+};
+
+static void zx2967_wdt_refresh(struct zx2967_wdt *wdt)
+{
+ unsigned int val;
+
+ spin_lock(&wdt->lock);
+
+ val = zx2967_wdt_read_reg(wdt->reg_base + ZX2967_WDT_REFRESH_REG);
+ val ^= ZX2967_WDT_REFRESH_MASK;
+ zx2967_wdt_write_reg(val, wdt->reg_base + ZX2967_WDT_REFRESH_REG);
+
+ spin_unlock(&wdt->lock);
+}
+
+static void __zx2967_wdt_stop(struct zx2967_wdt *wdt)
+{
+ unsigned int val;
+
+ spin_lock(&wdt->lock);
+
+ val = zx2967_wdt_read_reg(wdt->reg_base + ZX2967_WDT_START_REG);
+ val &= ~(ZX2967_WDT_START_EN);
+ zx2967_wdt_write_reg(val, wdt->reg_base + ZX2967_WDT_START_REG);
+
+ spin_unlock(&wdt->lock);
+}
+
+static void __zx2967_wdt_start(struct zx2967_wdt *wdt)
+{
+ unsigned int val;
+
+ spin_lock(&wdt->lock);
+
+ val = zx2967_wdt_read_reg(wdt->reg_base + ZX2967_WDT_START_REG);
+ val |= ZX2967_WDT_START_EN;
+ zx2967_wdt_write_reg(val, wdt->reg_base + ZX2967_WDT_START_REG);
+
+ spin_unlock(&wdt->lock);
+}
+
+static unsigned int
+__zx2967_wdt_set_timeout(struct zx2967_wdt *wdt, unsigned int timeout)
+{
+ unsigned int freq = clk_get_rate(wdt->clock);
+ unsigned int divisor = ZX2967_WDT_DIV_DEFAULT, count;
+
+ count = timeout * freq;
+ if (count > divisor * ZX2967_WDT_MAX_COUNT)
+ divisor = DIV_ROUND_UP(count, ZX2967_WDT_MAX_COUNT);
+ count = DIV_ROUND_UP(count, divisor);
+ zx2967_wdt_write_reg(ZX2967_WDT_CFG_DIV(divisor),
+ wdt->reg_base + ZX2967_WDT_CFG_REG);
+ zx2967_wdt_write_reg(count, wdt->reg_base + ZX2967_WDT_LOAD_REG);
+ zx2967_wdt_refresh(wdt);
+
+ wdt->load = count;
+ dev_info(wdt->dev, "count=%d, timeout=%d, divisor=%d\n",
+ count, timeout, divisor);
+
+ return (count * divisor) / freq;
+}
+
+static int zx2967_wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ struct zx2967_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ if (watchdog_timeout_invalid(&wdt->wdt_device, timeout)) {
+ dev_err(wdt->dev, "timeout %d is invalid\n", timeout);
+
+ return -EINVAL;
+ }
+
+ wdd->timeout = __zx2967_wdt_set_timeout(wdt, timeout);
+
+ return 0;
+}
+
+static int zx2967_wdt_start(struct watchdog_device *wdd)
+{
+ struct zx2967_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ __zx2967_wdt_stop(wdt);
+ zx2967_wdt_set_timeout(wdd, wdd->timeout);
+ __zx2967_wdt_start(wdt);
+
+ return 0;
+}
+
+static int zx2967_wdt_stop(struct watchdog_device *wdd)
+{
+ struct zx2967_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ __zx2967_wdt_stop(wdt);
+
+ return 0;
+}
+
+static int zx2967_wdt_keepalive(struct watchdog_device *wdd)
+{
+ struct zx2967_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ zx2967_wdt_refresh(wdt);
+
+ return 0;
+}
+
+#define ZX2967_WDT_OPTIONS \
+ (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
+static const struct watchdog_info zx2967_wdt_ident = {
+ .options = ZX2967_WDT_OPTIONS,
+ .firmware_version = 0,
+ .identity = "zx2967 watchdog",
+};
+
+static struct watchdog_ops zx2967_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = zx2967_wdt_start,
+ .stop = zx2967_wdt_stop,
+ .ping = zx2967_wdt_keepalive,
+ .set_timeout = zx2967_wdt_set_timeout,
+};
+
+static void zx2967_wdt_fix_sysdown(struct zx2967_wdt *wdt)
+{
+ __zx2967_wdt_stop(wdt);
+ __zx2967_wdt_set_timeout(wdt, 15);
+ __zx2967_wdt_start(wdt);
+}
+
+static int zx2967_wdt_notify_sys(struct notifier_block *this,
+ unsigned long code, void *unused)
+{
+ struct zx2967_wdt *wdt = container_of(this, struct zx2967_wdt,
+ reboot_handler);
+
+ wdt->flags |= ZX2967_WDT_FLAG_REBOOT_MON;
+ switch (code) {
+ case SYS_HALT:
+ case SYS_POWER_OFF:
+ case SYS_RESTART:
+ zx2967_wdt_fix_sysdown(wdt);
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int zx2967_wdt_restart(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ struct zx2967_wdt *wdt;
+
+ wdt = container_of(this, struct zx2967_wdt, restart_handler);
+
+ zx2967_wdt_stop(&wdt->wdt_device);
+
+ zx2967_wdt_write_reg(0x80, wdt->reg_base + ZX2967_WDT_LOAD_REG);
+ zx2967_wdt_refresh(wdt);
+ zx2967_wdt_write_reg(ZX2967_WDT_START_EN,
+ wdt->reg_base + ZX2967_WDT_START_REG);
+
+ zx2967_wdt_start(&wdt->wdt_device);
+ /* wait for reset*/
+ mdelay(500);
+
+ return NOTIFY_DONE;
+}
+
+static void zx2967_reset_mask_config(struct device *dev)
+{
+ struct device_node *np = NULL;
+ void __iomem *reg;
+ unsigned int val, mask, config, size;
+ const unsigned int *prop;
+
+ prop = of_get_property(dev->of_node, "reset-mask-config", &size);
+ if (size < (sizeof(*prop) * 2)) {
+ dev_err(dev, "bad data for reset-mask-config");
+ return;
+ }
+ config = be32_to_cpup(prop++);
+ mask = be32_to_cpup(prop);
+ np = of_find_compatible_node(NULL, NULL, "zte,aon-sysctrl");
+ if (!np) {
+ dev_err(dev, "Cannot found pcu device node\n");
+ return;
+ }
+ reg = of_iomap(np, 0) + ZX2967_RESET_MASK_REG;
+ of_node_put(np);
+
+ val = readl(reg);
+ val &= ~mask;
+ val |= config;
+ writel(val, reg);
+}
+
+static int zx2967_wdt_probe(struct platform_device *pdev)
+{
+ struct device *dev;
+ struct zx2967_wdt *wdt;
+ struct resource *base;
+ int err, ret = 0;
+ unsigned int rate, val;
+
+ struct reset_control *rstc;
+
+ dev = &pdev->dev;
+
+ wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
+ if (!wdt) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ platform_set_drvdata(pdev, wdt);
+
+ wdt->dev = dev;
+ spin_lock_init(&wdt->lock);
+
+ wdt->wdt_device.info = &zx2967_wdt_ident;
+ wdt->wdt_device.ops = &zx2967_wdt_ops;
+ wdt->wdt_device.timeout = ZX2967_WDT_DEFAULT_TIMEOUT;
+ wdt->wdt_device.max_timeout = ZX2967_WDT_MAX_TIMEOUT;
+ wdt->wdt_device.min_timeout = ZX2967_WDT_MIN_TIMEOUT;
+ wdt->wdt_device.parent = &pdev->dev;
+
+ base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ wdt->reg_base = devm_ioremap_resource(dev, base);
+
+ if (of_find_property(dev->of_node, "reset-mask-config", NULL))
+ zx2967_reset_mask_config(dev);
+
+ wdt->reboot_handler.notifier_call = zx2967_wdt_notify_sys;
+ ret = register_reboot_notifier(&wdt->reboot_handler);
+ wdt->clock = devm_clk_get(dev, "wdtclk");
+ if (IS_ERR(wdt->clock)) {
+ dev_err(dev, "failed to find watchdog clock source\n");
+ ret = PTR_ERR(wdt->clock);
+ goto out;
+ }
+ ret = clk_prepare_enable(wdt->clock);
+ if (ret < 0) {
+ dev_err(dev, "failed to enable clock\n");
+ goto out;
+ }
+
+ rate = clk_get_rate(wdt->clock);
+ if (rate == 24000000)
+ ret = clk_set_rate(wdt->clock, 32768);
+ rate = clk_get_rate(wdt->clock);
+
+ rstc = devm_reset_control_get(dev, "wdtrst");
+ if (!rstc) {
+ dev_info(dev, "rstc get failed");
+ } else {
+ reset_control_assert(rstc);
+ mdelay(10);
+ reset_control_deassert(rstc);
+ }
+
+ watchdog_set_drvdata(&wdt->wdt_device, wdt);
+
+ watchdog_init_timeout(&wdt->wdt_device, timeout, &pdev->dev);
+ watchdog_set_nowayout(&wdt->wdt_device, nowayout);
+
+ zx2967_wdt_stop(&wdt->wdt_device);
+
+ err = watchdog_register_device(&wdt->wdt_device);
+ if (unlikely(err)) {
+ ret = err;
+ goto fail_register;
+ }
+
+ wdt->restart_handler.notifier_call = zx2967_wdt_restart;
+ wdt->restart_handler.priority = 128;
+ ret = register_restart_handler(&wdt->restart_handler);
+ if (ret) {
+ pr_err("cannot register restart handler, %d\n", ret);
+ goto fail_restart;
+ }
+
+ val = zx2967_wdt_read_reg(wdt->reg_base + ZX2967_WDT_START_REG);
+ dev_info(&pdev->dev, "watchdog enabled (timeout=%d sec, nowayout=%d)",
+ wdt->wdt_device.timeout, nowayout);
+
+ return 0;
+
+fail_restart:
+ watchdog_unregister_device(&wdt->wdt_device);
+fail_register:
+ clk_disable_unprepare(wdt->clock);
+out:
+ return ret;
+}
+
+static int zx2967_wdt_remove(struct platform_device *pdev)
+{
+ struct zx2967_wdt *wdt = platform_get_drvdata(pdev);
+
+ unregister_restart_handler(&wdt->restart_handler);
+ watchdog_unregister_device(&wdt->wdt_device);
+ clk_disable_unprepare(wdt->clock);
+
+ return 0;
+}
+
+static void zx2967_wdt_shutdown(struct platform_device *pdev)
+{
+ struct zx2967_wdt *wdt = platform_get_drvdata(pdev);
+
+ if (!(wdt->flags & ZX2967_WDT_FLAG_REBOOT_MON))
+ zx2967_wdt_stop(&wdt->wdt_device);
+}
+
+static const struct of_device_id zx2967_wdt_match[] = {
+ { .compatible = "zte,zx296718-wdt", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, zx2967_wdt_match);
+
+static const struct platform_device_id zx2967_wdt_ids[] = {
+ { .name = "zx2967-wdt", },
+ {}
+};
+MODULE_DEVICE_TABLE(platform, zx2967_wdt_ids);
+
+static struct platform_driver zx2967_wdt_driver = {
+ .probe = zx2967_wdt_probe,
+ .remove = zx2967_wdt_remove,
+ .shutdown = zx2967_wdt_shutdown,
+ .id_table = zx2967_wdt_ids,
+ .driver = {
+ .name = "zx2967-wdt",
+ .of_match_table = of_match_ptr(zx2967_wdt_match),
+ },
+};
+module_platform_driver(zx2967_wdt_driver);
+
+MODULE_AUTHOR("Baoyou Xie <baoyou.xie@linaro.org>");
+MODULE_DESCRIPTION("ZTE zx2967 Watchdog Device Driver");
+MODULE_LICENSE("GPL");
--
2.7.4