[alsa-devel] [PATCH v2 2/4] watchdog: mtk_wdt: mt8183: Add reset controller
Guenter Roeck
linux at roeck-us.net
Sat Sep 28 19:49:23 CEST 2019
On Fri, Sep 27, 2019 at 06:31:55PM +0800, Jiaxin Yu wrote:
> From: "yong.liang" <yong.liang at mediatek.com>
>
> Provide assert/deassert/reset API in watchdog driver.
> Register reset controller for toprgu device in watchdog probe.
>
> Signed-off-by: yong.liang <yong.liang at mediatek.com>
> ---
> drivers/watchdog/Kconfig | 1 +
> drivers/watchdog/mtk_wdt.c | 110 ++++++++++++++++++++++++++++++++++++-
> 2 files changed, 110 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 2e07caab9db2..629249fe5305 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -717,6 +717,7 @@ config MEDIATEK_WATCHDOG
> tristate "Mediatek SoCs watchdog support"
> depends on ARCH_MEDIATEK || COMPILE_TEST
> select WATCHDOG_CORE
> + select RESET_CONTROLLER
> help
> Say Y here to include support for the watchdog timer
> in Mediatek SoCs.
> diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
> index 9c3d0033260d..660fb0e48d8e 100644
> --- a/drivers/watchdog/mtk_wdt.c
> +++ b/drivers/watchdog/mtk_wdt.c
> @@ -20,6 +20,10 @@
> #include <linux/types.h>
> #include <linux/watchdog.h>
> #include <linux/delay.h>
> +#include <linux/reset-controller.h>
> +#include <linux/slab.h>
> +#include <linux/reset.h>
> +#include <linux/of_device.h>
>
> #define WDT_MAX_TIMEOUT 31
> #define WDT_MIN_TIMEOUT 1
> @@ -44,17 +48,113 @@
> #define WDT_SWRST 0x14
> #define WDT_SWRST_KEY 0x1209
>
> +#define WDT_SWSYSRST 0x18U
> +#define WDT_SWSYS_RST_KEY 0x88000000
> +
> #define DRV_NAME "mtk-wdt"
> #define DRV_VERSION "1.0"
>
> static bool nowayout = WATCHDOG_NOWAYOUT;
> static unsigned int timeout;
>
> +struct toprgu_reset {
> + spinlock_t lock; /* Protects reset_controller access */
> + void __iomem *toprgu_swrst_base;
> + int regofs;
> + struct reset_controller_dev rcdev;
> +};
> +
> struct mtk_wdt_dev {
> struct watchdog_device wdt_dev;
> void __iomem *wdt_base;
> + struct toprgu_reset reset_controller;
> + const struct mtk_wdt_compatible *dev_comp;
> +};
> +
> +struct mtk_wdt_compatible {
> + int sw_rst_num;
> +};
> +
> +static int toprgu_reset_assert(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + unsigned int tmp;
> + unsigned long flags;
> + struct toprgu_reset *data = container_of(rcdev,
> + struct toprgu_reset, rcdev);
> +
> + spin_lock_irqsave(&data->lock, flags);
> +
> + tmp = __raw_readl(data->toprgu_swrst_base + data->regofs);
> + tmp |= BIT(id);
> + tmp |= WDT_SWSYS_RST_KEY;
> + writel(tmp, data->toprgu_swrst_base + data->regofs);
> +
> + spin_unlock_irqrestore(&data->lock, flags);
> +
> + return 0;
> +}
> +
> +static int toprgu_reset_deassert(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + unsigned int tmp;
> + unsigned long flags;
> + struct toprgu_reset *data = container_of(rcdev,
> + struct toprgu_reset, rcdev);
> +
> + spin_lock_irqsave(&data->lock, flags);
> +
> + tmp = __raw_readl(data->toprgu_swrst_base + data->regofs);
> + tmp &= ~BIT(id);
> + tmp |= WDT_SWSYS_RST_KEY;
> + writel(tmp, data->toprgu_swrst_base + data->regofs);
> +
> + spin_unlock_irqrestore(&data->lock, flags);
> +
> + return 0;
> +}
> +
> +static int toprgu_reset(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + int ret;
> +
> + ret = toprgu_reset_assert(rcdev, id);
> + if (ret)
> + return ret;
> +
> + return toprgu_reset_deassert(rcdev, id);
> +}
> +
> +static struct reset_control_ops toprgu_reset_ops = {
> + .assert = toprgu_reset_assert,
> + .deassert = toprgu_reset_deassert,
> + .reset = toprgu_reset,
> };
>
> +static void toprgu_register_reset_controller(struct platform_device *pdev,
> + int regofs)
> +{
> + int ret;
> + struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
> +
> + spin_lock_init(&mtk_wdt->reset_controller.lock);
> +
> + mtk_wdt->dev_comp = of_device_get_match_data(&pdev->dev);
> + mtk_wdt->reset_controller.toprgu_swrst_base = mtk_wdt->wdt_base;
> + mtk_wdt->reset_controller.regofs = regofs;
> + mtk_wdt->reset_controller.rcdev.owner = THIS_MODULE;
> + mtk_wdt->reset_controller.rcdev.nr_resets =
> + mtk_wdt->dev_comp->sw_rst_num;
> + mtk_wdt->reset_controller.rcdev.ops = &toprgu_reset_ops;
> + mtk_wdt->reset_controller.rcdev.of_node = pdev->dev.of_node;
> + ret = reset_controller_register(&mtk_wdt->reset_controller.rcdev);
> + if (ret != 0)
> + dev_err(&pdev->dev,
> + "couldn't register wdt reset controller: %d\n", ret);
> +}
> +
> static int mtk_wdt_restart(struct watchdog_device *wdt_dev,
> unsigned long action, void *data)
> {
> @@ -187,9 +287,12 @@ static int mtk_wdt_probe(struct platform_device *pdev)
> if (unlikely(err))
> return err;
>
> - dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)\n",
> + dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)\n",
> mtk_wdt->wdt_dev.timeout, nowayout);
>
> + mtk_wdt->dev_comp = of_device_get_match_data(&pdev->dev);
> + if (mtk_wdt->dev_comp)
> + toprgu_register_reset_controller(pdev, WDT_SWSYSRST);
Please explain why you can not use the watchdog device built-in support
for handling system resets.
Guenter
> return 0;
> }
>
> @@ -217,7 +320,12 @@ static int mtk_wdt_resume(struct device *dev)
> }
> #endif
>
> +static const struct mtk_wdt_compatible mt8183_compat = {
> + .sw_rst_num = 18,
> +};
> +
> static const struct of_device_id mtk_wdt_dt_ids[] = {
> + { .compatible = "mediatek,mt8183-wdt", .data = &mt8183_compat },
> { .compatible = "mediatek,mt6589-wdt" },
> { /* sentinel */ }
> };
> --
> 2.18.0
>
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