On 01/24/2017 12:58 AM, Baoyou Xie wrote:
This patch adds watchdog controller driver for ZTE's zx2967 family.
Signed-off-by: Baoyou Xie <baoyou.xie@xxxxxxxxxx>
---
drivers/watchdog/Kconfig | 10 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/zx2967_wdt.c | 274 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 285 insertions(+)
create mode 100644 drivers/watchdog/zx2967_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index acb00b5..05093a2 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 0c3d35e..bf2d296 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..89a7018
--- /dev/null
+++ b/drivers/watchdog/zx2967_wdt.c
@@ -0,0 +1,274 @@
+/*
+ * watchdog driver for ZTE's zx2967 family
+ *
+ * Copyright (C) 2017 ZTE Ltd.
+ *
+ * Author: Baoyou Xie <baoyou.xie@xxxxxxxxxx>
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.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
Why not use the real maximum ? Just wondering.
+#define ZX2967_WDT_MAX_COUNT 0xffff
+
+#define ZX2967_WDT_CLK_FREQ 0x8000
+
+#define ZX2967_WDT_FLAG_REBOOT_MON BIT(0)
+
+struct zx2967_wdt {
+ struct watchdog_device wdt_device;
+ void __iomem *reg_base;
+ struct clk *clock;
+};
+
+static inline u32 zx2967_wdt_readl(struct zx2967_wdt *wdt, u16 reg)
+{
+ return readl_relaxed(wdt->reg_base + reg);
+}
+
+static inline void zx2967_wdt_writel(struct zx2967_wdt *wdt, u16 reg, u32 val)
+{
+ writel_relaxed(val | ZX2967_WDT_WRITEKEY, wdt->reg_base + reg);
+}
+
+static void zx2967_wdt_refresh(struct zx2967_wdt *wdt)
+{
+ u32 val;
+
+ val = zx2967_wdt_readl(wdt, ZX2967_WDT_REFRESH_REG);
+ val ^= ZX2967_WDT_REFRESH_MASK;
+ zx2967_wdt_writel(wdt, ZX2967_WDT_REFRESH_REG, val);
+}
+
+static int
+zx2967_wdt_set_timeout(struct watchdog_device *wdd, unsigned int timeout)
+{
+ struct zx2967_wdt *wdt = watchdog_get_drvdata(wdd);
+ unsigned int divisor = ZX2967_WDT_DIV_DEFAULT;
+ unsigned int count;
+
+ count = timeout * ZX2967_WDT_CLK_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_writel(wdt, ZX2967_WDT_CFG_REG, ZX2967_WDT_CFG_DIV(divisor));
+ zx2967_wdt_writel(wdt, ZX2967_WDT_LOAD_REG, count);
+ zx2967_wdt_refresh(wdt);
+ wdd->timeout = (count * divisor) / ZX2967_WDT_CLK_FREQ;
+
+ return 0;
+}
+
+static void __zx2967_wdt_start(struct zx2967_wdt *wdt)
+{
+ u32 val;
+
+ val = zx2967_wdt_readl(wdt, ZX2967_WDT_START_REG);
+ val |= ZX2967_WDT_START_EN;
+ zx2967_wdt_writel(wdt, ZX2967_WDT_START_REG, val);
+}
+
+static void __zx2967_wdt_stop(struct zx2967_wdt *wdt)
+{
+ u32 val;
+
+ val = zx2967_wdt_readl(wdt, ZX2967_WDT_START_REG);
+ val &= ~ZX2967_WDT_START_EN;
+ zx2967_wdt_writel(wdt, ZX2967_WDT_START_REG, val);
+}
+
+static int zx2967_wdt_start(struct watchdog_device *wdd)
+{
+ struct zx2967_wdt *wdt = watchdog_get_drvdata(wdd);
+
+ 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,
Does that make the code easier to read ? I presonally like being able to grep for
"options" in the driver to get a glimpse.
+ .firmware_version = 0,
Initializing a static field to 0 is unnecessary.
+ .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_reset_sysctrl(struct device *dev)
+{
+ int ret;
+ void __iomem *regmap;
+ unsigned int offset, mask, config;
+ struct of_phandle_args out_args;
+
+ ret = of_parse_phandle_with_fixed_args(dev->of_node,
+ "zte,wdt-reset-sysctrl", 3, 0, &out_args);
+ if (ret)
+ return;
+
+ offset = out_args.args[0];
+ config = out_args.args[1];
+ mask = out_args.args[2];
+
+ regmap = syscon_node_to_regmap(out_args.np);
+ if (IS_ERR(regmap))
+ return;
+
+ regmap_update_bits(regmap, offset, mask, config);
Another comment suggested adding
of_node_put(out_args.np);
here.
+}
+
+static int zx2967_wdt_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct zx2967_wdt *wdt;
+ struct resource *base;
+ int ret;
+ struct reset_control *rstc;
+
+ wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
+ if (!wdt)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, wdt);
+
+ 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 (IS_ERR(wdt->reg_base)) {
+ dev_err(dev, "ioremap failed\n");
+ return PTR_ERR(wdt->reg_base);
+ }
+
+ zx2967_wdt_reset_sysctrl(dev);
+
+ wdt->clock = devm_clk_get(dev, NULL);
+ if (IS_ERR(wdt->clock)) {
+ dev_err(dev, "failed to find watchdog clock source\n");
+ return PTR_ERR(wdt->clock);
+ }
+
+ ret = clk_prepare_enable(wdt->clock);
+ if (ret < 0) {
+ dev_err(dev, "failed to enable clock\n");
+ return ret;
+ }
+ clk_set_rate(wdt->clock, ZX2967_WDT_CLK_FREQ);
+
+ rstc = devm_reset_control_get(dev, NULL);
+ if (IS_ERR(rstc)) {
+ dev_err(dev, "failed to get rstc");
+ ret = PTR_ERR(rstc);
+ goto fail_get_reset_control;
+ }
+
+ reset_control_assert(rstc);
+ mdelay(10);
+ reset_control_deassert(rstc);
+
+ watchdog_set_drvdata(&wdt->wdt_device, wdt);
+ watchdog_set_nowayout(&wdt->wdt_device, WATCHDOG_NOWAYOUT);
A call to watchdog_init_timeout() may be valuable here to catch
timeout values from devicetree. Otherwise, displaying the selected timeout
below (which is a constant) doesn't really add much value.
+
+ ret = watchdog_register_device(&wdt->wdt_device);
+ if (ret)
+ goto fail_register;
+
+ dev_info(dev, "watchdog enabled (timeout=%d sec, nowayout=%d)",
+ wdt->wdt_device.timeout, WATCHDOG_NOWAYOUT);
+
+ return 0;
+
+fail_register:
+ watchdog_unregister_device(&wdt->wdt_device);
As asked before - why try to unregister if the registration failed ?
+fail_get_reset_control:
+ clk_disable_unprepare(wdt->clock);
+ return ret;
+}
+
+static int zx2967_wdt_remove(struct platform_device *pdev)
+{
+ struct zx2967_wdt *wdt = platform_get_drvdata(pdev);
+
+ watchdog_unregister_device(&wdt->wdt_device);
+ clk_disable_unprepare(wdt->clock);
+
+ return 0;
+}
+
+static const struct of_device_id zx2967_wdt_match[] = {
+ { .compatible = "zte,zx296718-wdt", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, zx2967_wdt_match);
+
+static struct platform_driver zx2967_wdt_driver = {
+ .probe = zx2967_wdt_probe,
+ .remove = zx2967_wdt_remove,
+ .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@xxxxxxxxxx>");
+MODULE_DESCRIPTION("ZTE zx2967 Watchdog Device Driver");
+MODULE_LICENSE("GPL v2");
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