Message ID | 20211122113554.15990-3-biju.das.jz@bp.renesas.com (mailing list archive) |
---|---|
State | Accepted |
Headers | show |
Series | Add WDT driver for RZ/G2L | expand |
On 11/22/21 3:35 AM, Biju Das wrote: > Add Watchdog Timer driver for RZ/G2L SoC. > > WDT IP block supports normal watchdog timer function and reset > request function due to CPU parity error. > > This driver currently supports normal watchdog timer function > and later will add support for reset request function due to > CPU parity error. > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> > Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > V2->V3: > * Added Rb tag from Guenter Roeck > V1->V2: > * started using clk_get/put instead of devm_clk_get/put > * Moved devm_add_action_or_reset after set_drvdata() and > * removed redundant action on devm_add_action_or_reset() failure. > RFC->V1 > * Removed pclk_rate from priv. > * rzg2l_wdt_write() returns void and Removed tiemout related to register update > * rzg2l_wdt_init_timeout() returns void and removed delays. > * removed set_bit(WDOG_HW_RUNNING,..) as we can stop watchdog > * renamed reset_assert_clock_disable->reset_assert_pm_disable_put > * started using devm_reset_control_get_exclusive() > * removed platform_set_drvdata(pdev, priv) as there is no user > * removed watchdog_set_restart_priority(&priv->wdev, 0) as 0 is the default. > * removed remove callback as it is empty. > --- > drivers/watchdog/Kconfig | 8 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/rzg2l_wdt.c | 255 +++++++++++++++++++++++++++++++++++ > 3 files changed, 264 insertions(+) > create mode 100644 drivers/watchdog/rzg2l_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 9d222ba17ec6..4760ee981263 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -881,6 +881,14 @@ config RENESAS_RZAWDT > This driver adds watchdog support for the integrated watchdogs in the > Renesas RZ/A SoCs. These watchdogs can be used to reset a system. > > +config RENESAS_RZG2LWDT > + tristate "Renesas RZ/G2L WDT Watchdog" > + depends on ARCH_RENESAS || COMPILE_TEST > + select WATCHDOG_CORE > + help > + This driver adds watchdog support for the integrated watchdogs in the > + Renesas RZ/G2L SoCs. These watchdogs can be used to reset a system. > + > config ASPEED_WATCHDOG > tristate "Aspeed BMC watchdog support" > depends on ARCH_ASPEED || COMPILE_TEST > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 2ee97064145b..9a3dc0bd271b 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -84,6 +84,7 @@ obj-$(CONFIG_LPC18XX_WATCHDOG) += lpc18xx_wdt.o > obj-$(CONFIG_BCM7038_WDT) += bcm7038_wdt.o > obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o > obj-$(CONFIG_RENESAS_RZAWDT) += rza_wdt.o > +obj-$(CONFIG_RENESAS_RZG2LWDT) += rzg2l_wdt.o > obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o > obj-$(CONFIG_STM32_WATCHDOG) += stm32_iwdg.o > obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o > diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c > new file mode 100644 > index 000000000000..77f1cfc5ecf6 > --- /dev/null > +++ b/drivers/watchdog/rzg2l_wdt.c > @@ -0,0 +1,255 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Renesas RZ/G2L WDT Watchdog Driver > + * > + * Copyright (C) 2021 Renesas Electronics Corporation > + */ > +#include <linux/bitops.h> > +#include <linux/clk.h> > +#include <linux/delay.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/pm_runtime.h> > +#include <linux/reset.h> > +#include <linux/watchdog.h> > + > +#define WDTCNT 0x00 > +#define WDTSET 0x04 > +#define WDTTIM 0x08 > +#define WDTINT 0x0C > +#define WDTCNT_WDTEN BIT(0) > +#define WDTINT_INTDISP BIT(0) > + > +#define WDT_DEFAULT_TIMEOUT 60U > + > +/* Setting period time register only 12 bit set in WDTSET[31:20] */ > +#define WDTSET_COUNTER_MASK (0xFFF00000) > +#define WDTSET_COUNTER_VAL(f) ((f) << 20) > + > +#define F2CYCLE_NSEC(f) (1000000000 / (f)) > +#define WDT_CYCLE_MSEC(f, wdttime) ((1024 * 1024 * (((u64)wdttime) + 1)) / \ > + ((f) / 1000000)) This macro generates a 64 bit divide operation - as noticed by 0-day - and will have to be rewritten. Guenter > + > +static bool nowayout = WATCHDOG_NOWAYOUT; > +module_param(nowayout, bool, 0); > +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" > + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); > + > +struct rzg2l_wdt_priv { > + void __iomem *base; > + struct watchdog_device wdev; > + struct reset_control *rstc; > + unsigned long osc_clk_rate; > + unsigned long delay; > +}; > + > +static void rzg2l_wdt_wait_delay(struct rzg2l_wdt_priv *priv) > +{ > + /* delay timer when change the setting register */ > + ndelay(priv->delay); > +} > + > +static void rzg2l_wdt_write(struct rzg2l_wdt_priv *priv, u32 val, unsigned int reg) > +{ > + if (reg == WDTSET) > + val &= WDTSET_COUNTER_MASK; > + > + writel_relaxed(val, priv->base + reg); > + /* Registers other than the WDTINT is always synchronized with WDT_CLK */ > + if (reg != WDTINT) > + rzg2l_wdt_wait_delay(priv); > +} > + > +static void rzg2l_wdt_init_timeout(struct watchdog_device *wdev) > +{ > + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); > + u32 time_out; > + > + /* Clear Lapsed Time Register and clear Interrupt */ > + rzg2l_wdt_write(priv, WDTINT_INTDISP, WDTINT); > + /* 2 consecutive overflow cycle needed to trigger reset */ > + time_out = (wdev->timeout / 2 * 1000000) / WDT_CYCLE_MSEC(priv->osc_clk_rate, 0); > + rzg2l_wdt_write(priv, WDTSET_COUNTER_VAL(time_out), WDTSET); > +} > + > +static int rzg2l_wdt_start(struct watchdog_device *wdev) > +{ > + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); > + > + reset_control_deassert(priv->rstc); > + pm_runtime_get_sync(wdev->parent); > + > + /* Initialize time out */ > + rzg2l_wdt_init_timeout(wdev); > + > + /* Initialize watchdog counter register */ > + rzg2l_wdt_write(priv, 0, WDTTIM); > + > + /* Enable watchdog timer*/ > + rzg2l_wdt_write(priv, WDTCNT_WDTEN, WDTCNT); > + > + return 0; > +} > + > +static int rzg2l_wdt_stop(struct watchdog_device *wdev) > +{ > + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); > + > + pm_runtime_put(wdev->parent); > + reset_control_assert(priv->rstc); > + > + return 0; > +} > + > +static int rzg2l_wdt_restart(struct watchdog_device *wdev, > + unsigned long action, void *data) > +{ > + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); > + > + /* Reset the module before we modify any register */ > + reset_control_reset(priv->rstc); > + pm_runtime_get_sync(wdev->parent); > + > + /* smallest counter value to reboot soon */ > + rzg2l_wdt_write(priv, WDTSET_COUNTER_VAL(1), WDTSET); > + > + /* Enable watchdog timer*/ > + rzg2l_wdt_write(priv, WDTCNT_WDTEN, WDTCNT); > + > + return 0; > +} > + > +static const struct watchdog_info rzg2l_wdt_ident = { > + .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, > + .identity = "Renesas RZ/G2L WDT Watchdog", > +}; > + > +static int rzg2l_wdt_ping(struct watchdog_device *wdev) > +{ > + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); > + > + rzg2l_wdt_write(priv, WDTINT_INTDISP, WDTINT); > + > + return 0; > +} > + > +static const struct watchdog_ops rzg2l_wdt_ops = { > + .owner = THIS_MODULE, > + .start = rzg2l_wdt_start, > + .stop = rzg2l_wdt_stop, > + .ping = rzg2l_wdt_ping, > + .restart = rzg2l_wdt_restart, > +}; > + > +static void rzg2l_wdt_reset_assert_pm_disable_put(void *data) > +{ > + struct watchdog_device *wdev = data; > + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); > + > + pm_runtime_put(wdev->parent); > + pm_runtime_disable(wdev->parent); > + reset_control_assert(priv->rstc); > +} > + > +static int rzg2l_wdt_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct rzg2l_wdt_priv *priv; > + unsigned long pclk_rate; > + struct clk *wdt_clk; > + int ret; > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->base = devm_platform_ioremap_resource(pdev, 0); > + if (IS_ERR(priv->base)) > + return PTR_ERR(priv->base); > + > + /* Get watchdog main clock */ > + wdt_clk = clk_get(&pdev->dev, "oscclk"); > + if (IS_ERR(wdt_clk)) > + return dev_err_probe(&pdev->dev, PTR_ERR(wdt_clk), "no oscclk"); > + > + priv->osc_clk_rate = clk_get_rate(wdt_clk); > + clk_put(wdt_clk); > + if (!priv->osc_clk_rate) > + return dev_err_probe(&pdev->dev, -EINVAL, "oscclk rate is 0"); > + > + /* Get Peripheral clock */ > + wdt_clk = clk_get(&pdev->dev, "pclk"); > + if (IS_ERR(wdt_clk)) > + return dev_err_probe(&pdev->dev, PTR_ERR(wdt_clk), "no pclk"); > + > + pclk_rate = clk_get_rate(wdt_clk); > + clk_put(wdt_clk); > + if (!pclk_rate) > + return dev_err_probe(&pdev->dev, -EINVAL, "pclk rate is 0"); > + > + priv->delay = F2CYCLE_NSEC(priv->osc_clk_rate) * 6 + F2CYCLE_NSEC(pclk_rate) * 9; > + > + priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); > + if (IS_ERR(priv->rstc)) > + return dev_err_probe(&pdev->dev, PTR_ERR(priv->rstc), > + "failed to get cpg reset"); > + > + reset_control_deassert(priv->rstc); > + pm_runtime_enable(&pdev->dev); > + ret = pm_runtime_resume_and_get(&pdev->dev); > + if (ret < 0) { > + dev_err(dev, "pm_runtime_resume_and_get failed ret=%pe", ERR_PTR(ret)); > + goto out_pm_get; > + } > + > + priv->wdev.info = &rzg2l_wdt_ident; > + priv->wdev.ops = &rzg2l_wdt_ops; > + priv->wdev.parent = dev; > + priv->wdev.min_timeout = 1; > + priv->wdev.max_timeout = WDT_CYCLE_MSEC(priv->osc_clk_rate, 0xfff); > + priv->wdev.timeout = WDT_DEFAULT_TIMEOUT; > + > + watchdog_set_drvdata(&priv->wdev, priv); > + ret = devm_add_action_or_reset(&pdev->dev, > + rzg2l_wdt_reset_assert_pm_disable_put, > + &priv->wdev); > + if (ret < 0) > + return ret; > + > + watchdog_set_nowayout(&priv->wdev, nowayout); > + watchdog_stop_on_unregister(&priv->wdev); > + > + ret = watchdog_init_timeout(&priv->wdev, 0, dev); > + if (ret) > + dev_warn(dev, "Specified timeout invalid, using default"); > + > + return devm_watchdog_register_device(&pdev->dev, &priv->wdev); > + > +out_pm_get: > + pm_runtime_disable(dev); > + reset_control_assert(priv->rstc); > + > + return ret; > +} > + > +static const struct of_device_id rzg2l_wdt_ids[] = { > + { .compatible = "renesas,rzg2l-wdt", }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, rzg2l_wdt_ids); > + > +static struct platform_driver rzg2l_wdt_driver = { > + .driver = { > + .name = "rzg2l_wdt", > + .of_match_table = rzg2l_wdt_ids, > + }, > + .probe = rzg2l_wdt_probe, > +}; > +module_platform_driver(rzg2l_wdt_driver); > + > +MODULE_DESCRIPTION("Renesas RZ/G2L WDT Watchdog Driver"); > +MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>"); > +MODULE_LICENSE("GPL v2"); >
Hi Guenter, Thanks for the feedback. > Subject: Re: [PATCH v3 2/2] watchdog: Add Watchdog Timer driver for RZ/G2L > > On 11/22/21 3:35 AM, Biju Das wrote: > > Add Watchdog Timer driver for RZ/G2L SoC. > > > > WDT IP block supports normal watchdog timer function and reset request > > function due to CPU parity error. > > > > This driver currently supports normal watchdog timer function and > > later will add support for reset request function due to CPU parity > > error. > > > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> > > Reviewed-by: Guenter Roeck <linux@roeck-us.net> > > --- > > V2->V3: > > * Added Rb tag from Guenter Roeck > > V1->V2: > > * started using clk_get/put instead of devm_clk_get/put > > * Moved devm_add_action_or_reset after set_drvdata() and > > * removed redundant action on devm_add_action_or_reset() failure. > > RFC->V1 > > * Removed pclk_rate from priv. > > * rzg2l_wdt_write() returns void and Removed tiemout related to > register update > > * rzg2l_wdt_init_timeout() returns void and removed delays. > > * removed set_bit(WDOG_HW_RUNNING,..) as we can stop watchdog > > * renamed reset_assert_clock_disable->reset_assert_pm_disable_put > > * started using devm_reset_control_get_exclusive() > > * removed platform_set_drvdata(pdev, priv) as there is no user > > * removed watchdog_set_restart_priority(&priv->wdev, 0) as 0 is the > default. > > * removed remove callback as it is empty. > > --- > > drivers/watchdog/Kconfig | 8 ++ > > drivers/watchdog/Makefile | 1 + > > drivers/watchdog/rzg2l_wdt.c | 255 +++++++++++++++++++++++++++++++++++ > > 3 files changed, 264 insertions(+) > > create mode 100644 drivers/watchdog/rzg2l_wdt.c > > > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index > > 9d222ba17ec6..4760ee981263 100644 > > --- a/drivers/watchdog/Kconfig > > +++ b/drivers/watchdog/Kconfig > > @@ -881,6 +881,14 @@ config RENESAS_RZAWDT > > This driver adds watchdog support for the integrated watchdogs in > the > > Renesas RZ/A SoCs. These watchdogs can be used to reset a system. > > > > +config RENESAS_RZG2LWDT > > + tristate "Renesas RZ/G2L WDT Watchdog" > > + depends on ARCH_RENESAS || COMPILE_TEST > > + select WATCHDOG_CORE > > + help > > + This driver adds watchdog support for the integrated watchdogs in > the > > + Renesas RZ/G2L SoCs. These watchdogs can be used to reset a > system. > > + > > config ASPEED_WATCHDOG > > tristate "Aspeed BMC watchdog support" > > depends on ARCH_ASPEED || COMPILE_TEST diff --git > > a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index > > 2ee97064145b..9a3dc0bd271b 100644 > > --- a/drivers/watchdog/Makefile > > +++ b/drivers/watchdog/Makefile > > @@ -84,6 +84,7 @@ obj-$(CONFIG_LPC18XX_WATCHDOG) += lpc18xx_wdt.o > > obj-$(CONFIG_BCM7038_WDT) += bcm7038_wdt.o > > obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o > > obj-$(CONFIG_RENESAS_RZAWDT) += rza_wdt.o > > +obj-$(CONFIG_RENESAS_RZG2LWDT) += rzg2l_wdt.o > > obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o > > obj-$(CONFIG_STM32_WATCHDOG) += stm32_iwdg.o > > obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o diff --git > > a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c new file > > mode 100644 index 000000000000..77f1cfc5ecf6 > > --- /dev/null > > +++ b/drivers/watchdog/rzg2l_wdt.c > > @@ -0,0 +1,255 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * Renesas RZ/G2L WDT Watchdog Driver > > + * > > + * Copyright (C) 2021 Renesas Electronics Corporation */ #include > > +<linux/bitops.h> #include <linux/clk.h> #include <linux/delay.h> > > +#include <linux/io.h> #include <linux/kernel.h> #include > > +<linux/module.h> #include <linux/of.h> #include > > +<linux/platform_device.h> #include <linux/pm_runtime.h> #include > > +<linux/reset.h> #include <linux/watchdog.h> > > + > > +#define WDTCNT 0x00 > > +#define WDTSET 0x04 > > +#define WDTTIM 0x08 > > +#define WDTINT 0x0C > > +#define WDTCNT_WDTEN BIT(0) > > +#define WDTINT_INTDISP BIT(0) > > + > > +#define WDT_DEFAULT_TIMEOUT 60U > > + > > +/* Setting period time register only 12 bit set in WDTSET[31:20] */ > > +#define WDTSET_COUNTER_MASK (0xFFF00000) > > +#define WDTSET_COUNTER_VAL(f) ((f) << 20) > > + > > +#define F2CYCLE_NSEC(f) (1000000000 / (f)) > > +#define WDT_CYCLE_MSEC(f, wdttime) ((1024 * 1024 * (((u64)wdttime) > + 1)) / \ > > + ((f) / 1000000)) > > This macro generates a 64 bit divide operation - as noticed by 0-day - and > will have to be rewritten. > OK, will rewrite like below to make the ARCH=m68k compiler happy -#define F2CYCLE_NSEC(f) (1000000000 / (f)) -#define WDT_CYCLE_MSEC(f, wdttime) ((1024 * 1024 * (((u64)wdttime) + 1)) / \ - ((f) / 1000000)) +#define F2CYCLE_NSEC(f) (1000000000 / (f)) +#define WDT_CYCLE_MSEC_CONST (1024 * 1024 * (u64)1000000) +static u32 rzg2l_wdt_get_cycle_msec(u32 cycle, u32 wdttime) +{ + /* timer_cycle = clk_cycle *1024 *1024 * (WDTTIME + 1) */ + u64 timer_cycle_ms = WDT_CYCLE_MSEC_CONST * (wdttime + 1); + do_div(timer_cycle_ms, cycle); + + return timer_cycle_ms; +} Regards, Biju > > > + > > +static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, > > +bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once > > +started (default=" > > + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); > > + > > +struct rzg2l_wdt_priv { > > + void __iomem *base; > > + struct watchdog_device wdev; > > + struct reset_control *rstc; > > + unsigned long osc_clk_rate; > > + unsigned long delay; > > +}; > > + > > +static void rzg2l_wdt_wait_delay(struct rzg2l_wdt_priv *priv) { > > + /* delay timer when change the setting register */ > > + ndelay(priv->delay); > > +} > > + > > +static void rzg2l_wdt_write(struct rzg2l_wdt_priv *priv, u32 val, > > +unsigned int reg) { > > + if (reg == WDTSET) > > + val &= WDTSET_COUNTER_MASK; > > + > > + writel_relaxed(val, priv->base + reg); > > + /* Registers other than the WDTINT is always synchronized with > WDT_CLK */ > > + if (reg != WDTINT) > > + rzg2l_wdt_wait_delay(priv); > > +} > > + > > +static void rzg2l_wdt_init_timeout(struct watchdog_device *wdev) { > > + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); > > + u32 time_out; > > + > > + /* Clear Lapsed Time Register and clear Interrupt */ > > + rzg2l_wdt_write(priv, WDTINT_INTDISP, WDTINT); > > + /* 2 consecutive overflow cycle needed to trigger reset */ > > + time_out = (wdev->timeout / 2 * 1000000) / WDT_CYCLE_MSEC(priv- > >osc_clk_rate, 0); > > + rzg2l_wdt_write(priv, WDTSET_COUNTER_VAL(time_out), WDTSET); } > > + > > +static int rzg2l_wdt_start(struct watchdog_device *wdev) { > > + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); > > + > > + reset_control_deassert(priv->rstc); > > + pm_runtime_get_sync(wdev->parent); > > + > > + /* Initialize time out */ > > + rzg2l_wdt_init_timeout(wdev); > > + > > + /* Initialize watchdog counter register */ > > + rzg2l_wdt_write(priv, 0, WDTTIM); > > + > > + /* Enable watchdog timer*/ > > + rzg2l_wdt_write(priv, WDTCNT_WDTEN, WDTCNT); > > + > > + return 0; > > +} > > + > > +static int rzg2l_wdt_stop(struct watchdog_device *wdev) { > > + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); > > + > > + pm_runtime_put(wdev->parent); > > + reset_control_assert(priv->rstc); > > + > > + return 0; > > +} > > + > > +static int rzg2l_wdt_restart(struct watchdog_device *wdev, > > + unsigned long action, void *data) { > > + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); > > + > > + /* Reset the module before we modify any register */ > > + reset_control_reset(priv->rstc); > > + pm_runtime_get_sync(wdev->parent); > > + > > + /* smallest counter value to reboot soon */ > > + rzg2l_wdt_write(priv, WDTSET_COUNTER_VAL(1), WDTSET); > > + > > + /* Enable watchdog timer*/ > > + rzg2l_wdt_write(priv, WDTCNT_WDTEN, WDTCNT); > > + > > + return 0; > > +} > > + > > +static const struct watchdog_info rzg2l_wdt_ident = { > > + .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | > WDIOF_SETTIMEOUT, > > + .identity = "Renesas RZ/G2L WDT Watchdog", }; > > + > > +static int rzg2l_wdt_ping(struct watchdog_device *wdev) { > > + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); > > + > > + rzg2l_wdt_write(priv, WDTINT_INTDISP, WDTINT); > > + > > + return 0; > > +} > > + > > +static const struct watchdog_ops rzg2l_wdt_ops = { > > + .owner = THIS_MODULE, > > + .start = rzg2l_wdt_start, > > + .stop = rzg2l_wdt_stop, > > + .ping = rzg2l_wdt_ping, > > + .restart = rzg2l_wdt_restart, > > +}; > > + > > +static void rzg2l_wdt_reset_assert_pm_disable_put(void *data) { > > + struct watchdog_device *wdev = data; > > + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); > > + > > + pm_runtime_put(wdev->parent); > > + pm_runtime_disable(wdev->parent); > > + reset_control_assert(priv->rstc); > > +} > > + > > +static int rzg2l_wdt_probe(struct platform_device *pdev) { > > + struct device *dev = &pdev->dev; > > + struct rzg2l_wdt_priv *priv; > > + unsigned long pclk_rate; > > + struct clk *wdt_clk; > > + int ret; > > + > > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > > + if (!priv) > > + return -ENOMEM; > > + > > + priv->base = devm_platform_ioremap_resource(pdev, 0); > > + if (IS_ERR(priv->base)) > > + return PTR_ERR(priv->base); > > + > > + /* Get watchdog main clock */ > > + wdt_clk = clk_get(&pdev->dev, "oscclk"); > > + if (IS_ERR(wdt_clk)) > > + return dev_err_probe(&pdev->dev, PTR_ERR(wdt_clk), "no > oscclk"); > > + > > + priv->osc_clk_rate = clk_get_rate(wdt_clk); > > + clk_put(wdt_clk); > > + if (!priv->osc_clk_rate) > > + return dev_err_probe(&pdev->dev, -EINVAL, "oscclk rate is 0"); > > + > > + /* Get Peripheral clock */ > > + wdt_clk = clk_get(&pdev->dev, "pclk"); > > + if (IS_ERR(wdt_clk)) > > + return dev_err_probe(&pdev->dev, PTR_ERR(wdt_clk), "no pclk"); > > + > > + pclk_rate = clk_get_rate(wdt_clk); > > + clk_put(wdt_clk); > > + if (!pclk_rate) > > + return dev_err_probe(&pdev->dev, -EINVAL, "pclk rate is 0"); > > + > > + priv->delay = F2CYCLE_NSEC(priv->osc_clk_rate) * 6 + > > +F2CYCLE_NSEC(pclk_rate) * 9; > > + > > + priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); > > + if (IS_ERR(priv->rstc)) > > + return dev_err_probe(&pdev->dev, PTR_ERR(priv->rstc), > > + "failed to get cpg reset"); > > + > > + reset_control_deassert(priv->rstc); > > + pm_runtime_enable(&pdev->dev); > > + ret = pm_runtime_resume_and_get(&pdev->dev); > > + if (ret < 0) { > > + dev_err(dev, "pm_runtime_resume_and_get failed ret=%pe", > ERR_PTR(ret)); > > + goto out_pm_get; > > + } > > + > > + priv->wdev.info = &rzg2l_wdt_ident; > > + priv->wdev.ops = &rzg2l_wdt_ops; > > + priv->wdev.parent = dev; > > + priv->wdev.min_timeout = 1; > > + priv->wdev.max_timeout = WDT_CYCLE_MSEC(priv->osc_clk_rate, 0xfff); > > + priv->wdev.timeout = WDT_DEFAULT_TIMEOUT; > > + > > + watchdog_set_drvdata(&priv->wdev, priv); > > + ret = devm_add_action_or_reset(&pdev->dev, > > + rzg2l_wdt_reset_assert_pm_disable_put, > > + &priv->wdev); > > + if (ret < 0) > > + return ret; > > + > > + watchdog_set_nowayout(&priv->wdev, nowayout); > > + watchdog_stop_on_unregister(&priv->wdev); > > + > > + ret = watchdog_init_timeout(&priv->wdev, 0, dev); > > + if (ret) > > + dev_warn(dev, "Specified timeout invalid, using default"); > > + > > + return devm_watchdog_register_device(&pdev->dev, &priv->wdev); > > + > > +out_pm_get: > > + pm_runtime_disable(dev); > > + reset_control_assert(priv->rstc); > > + > > + return ret; > > +} > > + > > +static const struct of_device_id rzg2l_wdt_ids[] = { > > + { .compatible = "renesas,rzg2l-wdt", }, > > + { /* sentinel */ } > > +}; > > +MODULE_DEVICE_TABLE(of, rzg2l_wdt_ids); > > + > > +static struct platform_driver rzg2l_wdt_driver = { > > + .driver = { > > + .name = "rzg2l_wdt", > > + .of_match_table = rzg2l_wdt_ids, > > + }, > > + .probe = rzg2l_wdt_probe, > > +}; > > +module_platform_driver(rzg2l_wdt_driver); > > + > > +MODULE_DESCRIPTION("Renesas RZ/G2L WDT Watchdog Driver"); > > +MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>"); > > +MODULE_LICENSE("GPL v2"); > >
Hi Biju, On Tue, Nov 30, 2021 at 10:59 AM Biju Das <biju.das.jz@bp.renesas.com> wrote: > > Subject: Re: [PATCH v3 2/2] watchdog: Add Watchdog Timer driver for RZ/G2L > > On 11/22/21 3:35 AM, Biju Das wrote: > > > Add Watchdog Timer driver for RZ/G2L SoC. > > > > > > WDT IP block supports normal watchdog timer function and reset request > > > function due to CPU parity error. > > > > > > This driver currently supports normal watchdog timer function and > > > later will add support for reset request function due to CPU parity > > > error. > > > > > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> > > > Reviewed-by: Guenter Roeck <linux@roeck-us.net> > > > --- /dev/null > > > +++ b/drivers/watchdog/rzg2l_wdt.c > > > @@ -0,0 +1,255 @@ > > > +// SPDX-License-Identifier: GPL-2.0 > > > +/* > > > + * Renesas RZ/G2L WDT Watchdog Driver > > > + * > > > + * Copyright (C) 2021 Renesas Electronics Corporation */ #include > > > +<linux/bitops.h> #include <linux/clk.h> #include <linux/delay.h> > > > +#include <linux/io.h> #include <linux/kernel.h> #include > > > +<linux/module.h> #include <linux/of.h> #include > > > +<linux/platform_device.h> #include <linux/pm_runtime.h> #include > > > +<linux/reset.h> #include <linux/watchdog.h> > > > + > > > +#define WDTCNT 0x00 > > > +#define WDTSET 0x04 > > > +#define WDTTIM 0x08 > > > +#define WDTINT 0x0C > > > +#define WDTCNT_WDTEN BIT(0) > > > +#define WDTINT_INTDISP BIT(0) > > > + > > > +#define WDT_DEFAULT_TIMEOUT 60U > > > + > > > +/* Setting period time register only 12 bit set in WDTSET[31:20] */ > > > +#define WDTSET_COUNTER_MASK (0xFFF00000) > > > +#define WDTSET_COUNTER_VAL(f) ((f) << 20) > > > + > > > +#define F2CYCLE_NSEC(f) (1000000000 / (f)) > > > +#define WDT_CYCLE_MSEC(f, wdttime) ((1024 * 1024 * (((u64)wdttime) > > + 1)) / \ > > > + ((f) / 1000000)) > > > > This macro generates a 64 bit divide operation - as noticed by 0-day - and > > will have to be rewritten. > > > > OK, will rewrite like below to make the ARCH=m68k compiler happy > > -#define F2CYCLE_NSEC(f) (1000000000 / (f)) > -#define WDT_CYCLE_MSEC(f, wdttime) ((1024 * 1024 * (((u64)wdttime) + 1)) / \ > - ((f) / 1000000)) > +#define F2CYCLE_NSEC(f) (1000000000 / (f)) > +#define WDT_CYCLE_MSEC_CONST (1024 * 1024 * (u64)1000000) 1000000ULL (casts are evil ;-) > > +static u32 rzg2l_wdt_get_cycle_msec(u32 cycle, u32 wdttime) cycle == priv->osc_clk_rate, i.e. unsigned long? > +{ > + /* timer_cycle = clk_cycle *1024 *1024 * (WDTTIME + 1) */ Comment not needed if you get rid of WDT_CYCLE_MSEC_CONST? > + u64 timer_cycle_ms = WDT_CYCLE_MSEC_CONST * (wdttime + 1); > + do_div(timer_cycle_ms, cycle); div64_ul()? > + > + return timer_cycle_ms; > +} Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
Hi Geert, Thanks for the feedback. > Subject: Re: [PATCH v3 2/2] watchdog: Add Watchdog Timer driver for RZ/G2L > > Hi Biju, > > On Tue, Nov 30, 2021 at 10:59 AM Biju Das <biju.das.jz@bp.renesas.com> > wrote: > > > Subject: Re: [PATCH v3 2/2] watchdog: Add Watchdog Timer driver for > > > RZ/G2L On 11/22/21 3:35 AM, Biju Das wrote: > > > > Add Watchdog Timer driver for RZ/G2L SoC. > > > > > > > > WDT IP block supports normal watchdog timer function and reset > > > > request function due to CPU parity error. > > > > > > > > This driver currently supports normal watchdog timer function and > > > > later will add support for reset request function due to CPU > > > > parity error. > > > > > > > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> > > > > Reviewed-by: Guenter Roeck <linux@roeck-us.net> > > > > > --- /dev/null > > > > +++ b/drivers/watchdog/rzg2l_wdt.c > > > > @@ -0,0 +1,255 @@ > > > > +// SPDX-License-Identifier: GPL-2.0 > > > > +/* > > > > + * Renesas RZ/G2L WDT Watchdog Driver > > > > + * > > > > + * Copyright (C) 2021 Renesas Electronics Corporation */ > > > > +#include <linux/bitops.h> #include <linux/clk.h> #include > > > > +<linux/delay.h> #include <linux/io.h> #include <linux/kernel.h> > > > > +#include <linux/module.h> #include <linux/of.h> #include > > > > +<linux/platform_device.h> #include <linux/pm_runtime.h> #include > > > > +<linux/reset.h> #include <linux/watchdog.h> > > > > + > > > > +#define WDTCNT 0x00 > > > > +#define WDTSET 0x04 > > > > +#define WDTTIM 0x08 > > > > +#define WDTINT 0x0C > > > > +#define WDTCNT_WDTEN BIT(0) > > > > +#define WDTINT_INTDISP BIT(0) > > > > + > > > > +#define WDT_DEFAULT_TIMEOUT 60U > > > > + > > > > +/* Setting period time register only 12 bit set in WDTSET[31:20] */ > > > > +#define WDTSET_COUNTER_MASK (0xFFF00000) > > > > +#define WDTSET_COUNTER_VAL(f) ((f) << 20) > > > > + > > > > +#define F2CYCLE_NSEC(f) (1000000000 / (f)) > > > > +#define WDT_CYCLE_MSEC(f, wdttime) ((1024 * 1024 * > > > > +(((u64)wdttime) > > > + 1)) / \ > > > > + ((f) / 1000000)) > > > > > > This macro generates a 64 bit divide operation - as noticed by 0-day > > > - and will have to be rewritten. > > > > > > > OK, will rewrite like below to make the ARCH=m68k compiler happy > > > > -#define F2CYCLE_NSEC(f) (1000000000 / (f)) > > -#define WDT_CYCLE_MSEC(f, wdttime) ((1024 * 1024 * (((u64)wdttime) > + 1)) / \ > > - ((f) / 1000000)) > > +#define F2CYCLE_NSEC(f) (1000000000 / (f)) > > +#define WDT_CYCLE_MSEC_CONST (1024 * 1024 * (u64)1000000) > > 1000000ULL (casts are evil ;-) OK will get rid of this macro as you suggested below. > > > > > +static u32 rzg2l_wdt_get_cycle_msec(u32 cycle, u32 wdttime) > > cycle == priv->osc_clk_rate, i.e. unsigned long? OK will make unsigned long. > > > +{ > > + /* timer_cycle = clk_cycle *1024 *1024 * (WDTTIME + 1) */ > > Comment not needed if you get rid of WDT_CYCLE_MSEC_CONST? Agreed. > > > + u64 timer_cycle_ms = WDT_CYCLE_MSEC_CONST * (wdttime + 1); > > + do_div(timer_cycle_ms, cycle); > > div64_ul()? OK, will do since it is 64 bit by 64 bit division. Regards, Biju > > > + > > + return timer_cycle_ms; > > +} > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux- > m68k.org > > In personal conversations with technical people, I call myself a hacker. > But when I'm talking to journalists I just say "programmer" or something > like that. > -- Linus Torvalds
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 9d222ba17ec6..4760ee981263 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -881,6 +881,14 @@ config RENESAS_RZAWDT This driver adds watchdog support for the integrated watchdogs in the Renesas RZ/A SoCs. These watchdogs can be used to reset a system. +config RENESAS_RZG2LWDT + tristate "Renesas RZ/G2L WDT Watchdog" + depends on ARCH_RENESAS || COMPILE_TEST + select WATCHDOG_CORE + help + This driver adds watchdog support for the integrated watchdogs in the + Renesas RZ/G2L SoCs. These watchdogs can be used to reset a system. + config ASPEED_WATCHDOG tristate "Aspeed BMC watchdog support" depends on ARCH_ASPEED || COMPILE_TEST diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 2ee97064145b..9a3dc0bd271b 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -84,6 +84,7 @@ obj-$(CONFIG_LPC18XX_WATCHDOG) += lpc18xx_wdt.o obj-$(CONFIG_BCM7038_WDT) += bcm7038_wdt.o obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o obj-$(CONFIG_RENESAS_RZAWDT) += rza_wdt.o +obj-$(CONFIG_RENESAS_RZG2LWDT) += rzg2l_wdt.o obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o obj-$(CONFIG_STM32_WATCHDOG) += stm32_iwdg.o obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c new file mode 100644 index 000000000000..77f1cfc5ecf6 --- /dev/null +++ b/drivers/watchdog/rzg2l_wdt.c @@ -0,0 +1,255 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas RZ/G2L WDT Watchdog Driver + * + * Copyright (C) 2021 Renesas Electronics Corporation + */ +#include <linux/bitops.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/reset.h> +#include <linux/watchdog.h> + +#define WDTCNT 0x00 +#define WDTSET 0x04 +#define WDTTIM 0x08 +#define WDTINT 0x0C +#define WDTCNT_WDTEN BIT(0) +#define WDTINT_INTDISP BIT(0) + +#define WDT_DEFAULT_TIMEOUT 60U + +/* Setting period time register only 12 bit set in WDTSET[31:20] */ +#define WDTSET_COUNTER_MASK (0xFFF00000) +#define WDTSET_COUNTER_VAL(f) ((f) << 20) + +#define F2CYCLE_NSEC(f) (1000000000 / (f)) +#define WDT_CYCLE_MSEC(f, wdttime) ((1024 * 1024 * (((u64)wdttime) + 1)) / \ + ((f) / 1000000)) + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +struct rzg2l_wdt_priv { + void __iomem *base; + struct watchdog_device wdev; + struct reset_control *rstc; + unsigned long osc_clk_rate; + unsigned long delay; +}; + +static void rzg2l_wdt_wait_delay(struct rzg2l_wdt_priv *priv) +{ + /* delay timer when change the setting register */ + ndelay(priv->delay); +} + +static void rzg2l_wdt_write(struct rzg2l_wdt_priv *priv, u32 val, unsigned int reg) +{ + if (reg == WDTSET) + val &= WDTSET_COUNTER_MASK; + + writel_relaxed(val, priv->base + reg); + /* Registers other than the WDTINT is always synchronized with WDT_CLK */ + if (reg != WDTINT) + rzg2l_wdt_wait_delay(priv); +} + +static void rzg2l_wdt_init_timeout(struct watchdog_device *wdev) +{ + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); + u32 time_out; + + /* Clear Lapsed Time Register and clear Interrupt */ + rzg2l_wdt_write(priv, WDTINT_INTDISP, WDTINT); + /* 2 consecutive overflow cycle needed to trigger reset */ + time_out = (wdev->timeout / 2 * 1000000) / WDT_CYCLE_MSEC(priv->osc_clk_rate, 0); + rzg2l_wdt_write(priv, WDTSET_COUNTER_VAL(time_out), WDTSET); +} + +static int rzg2l_wdt_start(struct watchdog_device *wdev) +{ + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); + + reset_control_deassert(priv->rstc); + pm_runtime_get_sync(wdev->parent); + + /* Initialize time out */ + rzg2l_wdt_init_timeout(wdev); + + /* Initialize watchdog counter register */ + rzg2l_wdt_write(priv, 0, WDTTIM); + + /* Enable watchdog timer*/ + rzg2l_wdt_write(priv, WDTCNT_WDTEN, WDTCNT); + + return 0; +} + +static int rzg2l_wdt_stop(struct watchdog_device *wdev) +{ + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); + + pm_runtime_put(wdev->parent); + reset_control_assert(priv->rstc); + + return 0; +} + +static int rzg2l_wdt_restart(struct watchdog_device *wdev, + unsigned long action, void *data) +{ + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); + + /* Reset the module before we modify any register */ + reset_control_reset(priv->rstc); + pm_runtime_get_sync(wdev->parent); + + /* smallest counter value to reboot soon */ + rzg2l_wdt_write(priv, WDTSET_COUNTER_VAL(1), WDTSET); + + /* Enable watchdog timer*/ + rzg2l_wdt_write(priv, WDTCNT_WDTEN, WDTCNT); + + return 0; +} + +static const struct watchdog_info rzg2l_wdt_ident = { + .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, + .identity = "Renesas RZ/G2L WDT Watchdog", +}; + +static int rzg2l_wdt_ping(struct watchdog_device *wdev) +{ + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); + + rzg2l_wdt_write(priv, WDTINT_INTDISP, WDTINT); + + return 0; +} + +static const struct watchdog_ops rzg2l_wdt_ops = { + .owner = THIS_MODULE, + .start = rzg2l_wdt_start, + .stop = rzg2l_wdt_stop, + .ping = rzg2l_wdt_ping, + .restart = rzg2l_wdt_restart, +}; + +static void rzg2l_wdt_reset_assert_pm_disable_put(void *data) +{ + struct watchdog_device *wdev = data; + struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); + + pm_runtime_put(wdev->parent); + pm_runtime_disable(wdev->parent); + reset_control_assert(priv->rstc); +} + +static int rzg2l_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rzg2l_wdt_priv *priv; + unsigned long pclk_rate; + struct clk *wdt_clk; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + /* Get watchdog main clock */ + wdt_clk = clk_get(&pdev->dev, "oscclk"); + if (IS_ERR(wdt_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(wdt_clk), "no oscclk"); + + priv->osc_clk_rate = clk_get_rate(wdt_clk); + clk_put(wdt_clk); + if (!priv->osc_clk_rate) + return dev_err_probe(&pdev->dev, -EINVAL, "oscclk rate is 0"); + + /* Get Peripheral clock */ + wdt_clk = clk_get(&pdev->dev, "pclk"); + if (IS_ERR(wdt_clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(wdt_clk), "no pclk"); + + pclk_rate = clk_get_rate(wdt_clk); + clk_put(wdt_clk); + if (!pclk_rate) + return dev_err_probe(&pdev->dev, -EINVAL, "pclk rate is 0"); + + priv->delay = F2CYCLE_NSEC(priv->osc_clk_rate) * 6 + F2CYCLE_NSEC(pclk_rate) * 9; + + priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); + if (IS_ERR(priv->rstc)) + return dev_err_probe(&pdev->dev, PTR_ERR(priv->rstc), + "failed to get cpg reset"); + + reset_control_deassert(priv->rstc); + pm_runtime_enable(&pdev->dev); + ret = pm_runtime_resume_and_get(&pdev->dev); + if (ret < 0) { + dev_err(dev, "pm_runtime_resume_and_get failed ret=%pe", ERR_PTR(ret)); + goto out_pm_get; + } + + priv->wdev.info = &rzg2l_wdt_ident; + priv->wdev.ops = &rzg2l_wdt_ops; + priv->wdev.parent = dev; + priv->wdev.min_timeout = 1; + priv->wdev.max_timeout = WDT_CYCLE_MSEC(priv->osc_clk_rate, 0xfff); + priv->wdev.timeout = WDT_DEFAULT_TIMEOUT; + + watchdog_set_drvdata(&priv->wdev, priv); + ret = devm_add_action_or_reset(&pdev->dev, + rzg2l_wdt_reset_assert_pm_disable_put, + &priv->wdev); + if (ret < 0) + return ret; + + watchdog_set_nowayout(&priv->wdev, nowayout); + watchdog_stop_on_unregister(&priv->wdev); + + ret = watchdog_init_timeout(&priv->wdev, 0, dev); + if (ret) + dev_warn(dev, "Specified timeout invalid, using default"); + + return devm_watchdog_register_device(&pdev->dev, &priv->wdev); + +out_pm_get: + pm_runtime_disable(dev); + reset_control_assert(priv->rstc); + + return ret; +} + +static const struct of_device_id rzg2l_wdt_ids[] = { + { .compatible = "renesas,rzg2l-wdt", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, rzg2l_wdt_ids); + +static struct platform_driver rzg2l_wdt_driver = { + .driver = { + .name = "rzg2l_wdt", + .of_match_table = rzg2l_wdt_ids, + }, + .probe = rzg2l_wdt_probe, +}; +module_platform_driver(rzg2l_wdt_driver); + +MODULE_DESCRIPTION("Renesas RZ/G2L WDT Watchdog Driver"); +MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>"); +MODULE_LICENSE("GPL v2");