On Tue, Jan 24, 2017 at 04:58:42PM +0800, 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 > +#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, > + .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_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); Go read the comment I made on your V4 post. > + 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); > +} > + > +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); Still no explanation as to why we need to have a busy loop here. I suggest you take a look at: https://www.kernel.org/doc/Documentation/timers/timers-howto.txt > + > + watchdog_set_drvdata(&wdt->wdt_device, wdt); > + watchdog_set_nowayout(&wdt->wdt_device, WATCHDOG_NOWAYOUT); > + > + 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); > +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"); > -- > 2.7.4 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html