On Wed, Jun 14, 2017 at 04:53:44PM +0900, Keiji Hayashibara wrote: > Add a watchdog driver for Socionext UniPhier series SoC. > Note that the timeout value for this device must be a power > of 2 because of the specification. > > Signed-off-by: Keiji Hayashibara <[email protected]>
Reviewed-by: Guenter Roeck <[email protected]> > --- > Documentation/watchdog/watchdog-parameters.txt | 6 + > drivers/watchdog/Kconfig | 12 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/uniphier_wdt.c | 268 > +++++++++++++++++++++++++ > 4 files changed, 287 insertions(+) > create mode 100644 drivers/watchdog/uniphier_wdt.c > > diff --git a/Documentation/watchdog/watchdog-parameters.txt > b/Documentation/watchdog/watchdog-parameters.txt > index 4f7d86d..6f9d7b4 100644 > --- a/Documentation/watchdog/watchdog-parameters.txt > +++ b/Documentation/watchdog/watchdog-parameters.txt > @@ -369,6 +369,12 @@ timeout: Watchdog timeout in seconds. (0<timeout<N, > default=60) > nowayout: Watchdog cannot be stopped once started > (default=kernel config parameter) > ------------------------------------------------- > +uniphier_wdt: > +timeout: Watchdog timeout in power of two seconds. > + (1 <= timeout <= 128, default=64) > +nowayout: Watchdog cannot be stopped once started > + (default=kernel config parameter) > +------------------------------------------------- > w83627hf_wdt: > wdt_io: w83627hf/thf WDT io port (default 0x2E) > timeout: Watchdog timeout in seconds. 1 <= timeout <= 255, default=60. > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 52a70ee..b83759d 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -744,6 +744,18 @@ config ZX2967_WATCHDOG > To compile this driver as a module, choose M here: the > module will be called zx2967_wdt. > > +config UNIPHIER_WATCHDOG > + tristate "UniPhier watchdog support" > + depends on ARCH_UNIPHIER || COMPILE_TEST > + depends on OF && MFD_SYSCON > + select WATCHDOG_CORE > + help > + Say Y here to include support watchdog timer embedded > + into the UniPhier system. > + > + To compile this driver as a module, choose M here: the > + module will be called uniphier_wdt. > + > # AVR32 Architecture > > config AT32AP700X_WDT > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index a2126e2..0928dac 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -84,6 +84,7 @@ 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 > +obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o > > # AVR32 Architecture > obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o > diff --git a/drivers/watchdog/uniphier_wdt.c b/drivers/watchdog/uniphier_wdt.c > new file mode 100644 > index 0000000..0ea2339 > --- /dev/null > +++ b/drivers/watchdog/uniphier_wdt.c > @@ -0,0 +1,268 @@ > +/* > + * Watchdog driver for the UniPhier watchdog timer > + * > + * (c) Copyright 2014 Panasonic Corporation > + * (c) Copyright 2016 Socionext Inc. > + * All rights reserved. > + * > + * 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. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include <linux/bitops.h> > +#include <linux/mfd/syscon.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/regmap.h> > +#include <linux/watchdog.h> > + > +/* WDT timer setting register */ > +#define WDTTIMSET 0x3004 > +#define WDTTIMSET_PERIOD_MASK (0xf << 0) > +#define WDTTIMSET_PERIOD_1_SEC (0x3 << 0) > + > +/* WDT reset selection register */ > +#define WDTRSTSEL 0x3008 > +#define WDTRSTSEL_RSTSEL_MASK (0x3 << 0) > +#define WDTRSTSEL_RSTSEL_BOTH (0x0 << 0) > +#define WDTRSTSEL_RSTSEL_IRQ_ONLY (0x2 << 0) > + > +/* WDT control register */ > +#define WDTCTRL 0x300c > +#define WDTCTRL_STATUS BIT(8) > +#define WDTCTRL_CLEAR BIT(1) > +#define WDTCTRL_ENABLE BIT(0) > + > +#define SEC_TO_WDTTIMSET_PRD(sec) \ > + (ilog2(sec) + WDTTIMSET_PERIOD_1_SEC) > + > +#define WDTST_TIMEOUT 1000 /* usec */ > + > +#define WDT_DEFAULT_TIMEOUT 64 /* Default is 64 seconds */ > +#define WDT_PERIOD_MIN 1 > +#define WDT_PERIOD_MAX 128 > + > +static unsigned int timeout = 0; > +static bool nowayout = WATCHDOG_NOWAYOUT; > + > +struct uniphier_wdt_dev { > + struct watchdog_device wdt_dev; > + struct regmap *regmap; > +}; > + > +/* > + * UniPhier Watchdog operations > + */ > +static int uniphier_watchdog_ping(struct watchdog_device *w) > +{ > + struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w); > + unsigned int val; > + int ret; > + > + /* Clear counter */ > + ret = regmap_write_bits(wdev->regmap, WDTCTRL, > + WDTCTRL_CLEAR, WDTCTRL_CLEAR); > + if (!ret) > + /* > + * As SoC specification, after clear counter, > + * it needs to wait until counter status is 1. > + */ > + ret = regmap_read_poll_timeout(wdev->regmap, WDTCTRL, val, > + (val & WDTCTRL_STATUS), > + 0, WDTST_TIMEOUT); > + > + return ret; > +} > + > +static int __uniphier_watchdog_start(struct regmap *regmap, unsigned int sec) > +{ > + unsigned int val; > + int ret; > + > + ret = regmap_read_poll_timeout(regmap, WDTCTRL, val, > + !(val & WDTCTRL_STATUS), > + 0, WDTST_TIMEOUT); > + if (ret) > + return ret; > + > + /* Setup period */ > + ret = regmap_write(regmap, WDTTIMSET, > + SEC_TO_WDTTIMSET_PRD(sec)); > + if (ret) > + return ret; > + > + /* Enable and clear watchdog */ > + ret = regmap_write(regmap, WDTCTRL, WDTCTRL_ENABLE | WDTCTRL_CLEAR); > + if (!ret) > + /* > + * As SoC specification, after clear counter, > + * it needs to wait until counter status is 1. > + */ > + ret = regmap_read_poll_timeout(regmap, WDTCTRL, val, > + (val & WDTCTRL_STATUS), > + 0, WDTST_TIMEOUT); > + > + return ret; > +} > + > +static int __uniphier_watchdog_stop(struct regmap *regmap) > +{ > + /* Disable and stop watchdog */ > + return regmap_write_bits(regmap, WDTCTRL, WDTCTRL_ENABLE, 0); > +} > + > +static int __uniphier_watchdog_restart(struct regmap *regmap, unsigned int > sec) > +{ > + int ret; > + > + ret = __uniphier_watchdog_stop(regmap); > + if (ret) > + return ret; > + > + return __uniphier_watchdog_start(regmap, sec); > +} > + > +static int uniphier_watchdog_start(struct watchdog_device *w) > +{ > + struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w); > + unsigned int tmp_timeout; > + > + tmp_timeout = roundup_pow_of_two(w->timeout); > + > + return __uniphier_watchdog_start(wdev->regmap, tmp_timeout); > +} > + > +static int uniphier_watchdog_stop(struct watchdog_device *w) > +{ > + struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w); > + > + return __uniphier_watchdog_stop(wdev->regmap); > +} > + > +static int uniphier_watchdog_set_timeout(struct watchdog_device *w, > + unsigned int t) > +{ > + struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w); > + unsigned int tmp_timeout; > + int ret; > + > + tmp_timeout = roundup_pow_of_two(t); > + if (tmp_timeout == w->timeout) > + return 0; > + > + if (watchdog_active(w)) { > + ret = __uniphier_watchdog_restart(wdev->regmap, tmp_timeout); > + if (ret) > + return ret; > + } > + > + w->timeout = tmp_timeout; > + > + return 0; > +} > + > +/* > + * Kernel Interfaces > + */ > +static const struct watchdog_info uniphier_wdt_info = { > + .identity = "uniphier-wdt", > + .options = WDIOF_SETTIMEOUT | > + WDIOF_KEEPALIVEPING | > + WDIOF_MAGICCLOSE | > + WDIOF_OVERHEAT, > +}; > + > +static const struct watchdog_ops uniphier_wdt_ops = { > + .owner = THIS_MODULE, > + .start = uniphier_watchdog_start, > + .stop = uniphier_watchdog_stop, > + .ping = uniphier_watchdog_ping, > + .set_timeout = uniphier_watchdog_set_timeout, > +}; > + > +static int uniphier_wdt_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct uniphier_wdt_dev *wdev; > + struct regmap *regmap; > + struct device_node *parent; > + int ret; > + > + wdev = devm_kzalloc(dev, sizeof(*wdev), GFP_KERNEL); > + if (!wdev) > + return -ENOMEM; > + > + platform_set_drvdata(pdev, wdev); > + > + parent = of_get_parent(dev->of_node); /* parent should be syscon node */ > + regmap = syscon_node_to_regmap(parent); > + of_node_put(parent); > + if (IS_ERR(regmap)) > + return PTR_ERR(regmap); > + > + wdev->regmap = regmap; > + wdev->wdt_dev.info = &uniphier_wdt_info; > + wdev->wdt_dev.ops = &uniphier_wdt_ops; > + wdev->wdt_dev.max_timeout = WDT_PERIOD_MAX; > + wdev->wdt_dev.min_timeout = WDT_PERIOD_MIN; > + wdev->wdt_dev.parent = dev; > + > + if (watchdog_init_timeout(&wdev->wdt_dev, timeout, dev) < 0) { > + wdev->wdt_dev.timeout = WDT_DEFAULT_TIMEOUT; > + } > + watchdog_set_nowayout(&wdev->wdt_dev, nowayout); > + watchdog_stop_on_reboot(&wdev->wdt_dev); > + > + watchdog_set_drvdata(&wdev->wdt_dev, wdev); > + > + uniphier_watchdog_stop(&wdev->wdt_dev); > + ret = regmap_write(wdev->regmap, WDTRSTSEL, WDTRSTSEL_RSTSEL_BOTH); > + if (ret) > + return ret; > + > + ret = devm_watchdog_register_device(dev, &wdev->wdt_dev); > + if (ret) > + return ret; > + > + dev_info(dev, "watchdog driver (timeout=%d sec, nowayout=%d)\n", > + wdev->wdt_dev.timeout, nowayout); > + > + return 0; > +} > + > +static const struct of_device_id uniphier_wdt_dt_ids[] = { > + { .compatible = "socionext,uniphier-wdt" }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, uniphier_wdt_dt_ids); > + > +static struct platform_driver uniphier_wdt_driver = { > + .probe = uniphier_wdt_probe, > + .driver = { > + .name = "uniphier-wdt", > + .of_match_table = uniphier_wdt_dt_ids, > + }, > +}; > + > +module_platform_driver(uniphier_wdt_driver); > + > +module_param(timeout, uint, 0000); > +MODULE_PARM_DESC(timeout, > + "Watchdog timeout seconds in power of 2. (0 < timeout < 128, default=" > + __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")"); > + > +module_param(nowayout, bool, 0000); > +MODULE_PARM_DESC(nowayout, > + "Watchdog cannot be stopped once started (default=" > + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); > + > +MODULE_AUTHOR("Keiji Hayashibara <[email protected]>"); > +MODULE_DESCRIPTION("UniPhier Watchdog Device Driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.7.4 >
