[PATCH v3 1/4] watchdog: meson: Enable meson SoC specific data

[Guenter Roeck]

On 11/08/2015 04:18 AM, Carlo Caione wrote:
> From: Carlo Caione <carlo at endlessm.com>
>
> With this patch we refactor the driver code to enable watchdog support
> for all platforms based on Amlogic meson SoCs.
> The new default timeout is also now chosen considering the maximum
> timeout allowed by the SoC.
>
> Signed-off-by: Carlo Caione <carlo at endlessm.com>

Reviewed-by: Guenter Roeck <linux at roeck-us.net>

> ---
>   drivers/watchdog/meson_wdt.c | 58 +++++++++++++++++++++++++++++++-------------
>   1 file changed, 41 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/watchdog/meson_wdt.c b/drivers/watchdog/meson_wdt.c
> index 1f4155e..89734f0 100644
> --- a/drivers/watchdog/meson_wdt.c
> +++ b/drivers/watchdog/meson_wdt.c
> @@ -19,6 +19,7 @@
>   #include <linux/moduleparam.h>
>   #include <linux/notifier.h>
>   #include <linux/of.h>
> +#include <linux/of_device.h>
>   #include <linux/platform_device.h>
>   #include <linux/reboot.h>
>   #include <linux/types.h>
> @@ -27,35 +28,47 @@
>   #define DRV_NAME		"meson_wdt"
>
>   #define MESON_WDT_TC		0x00
> -#define MESON_WDT_TC_EN		BIT(22)
> -#define MESON_WDT_TC_TM_MASK	0x3fffff
>   #define MESON_WDT_DC_RESET	(3 << 24)
>
>   #define MESON_WDT_RESET		0x04
>
>   #define MESON_WDT_TIMEOUT	30
>   #define MESON_WDT_MIN_TIMEOUT	1
> -#define MESON_WDT_MAX_TIMEOUT	(MESON_WDT_TC_TM_MASK / 100000)
>
> -#define MESON_SEC_TO_TC(s)	((s) * 100000)
> +#define MESON_SEC_TO_TC(s, c)	((s) * (c))
>
>   static bool nowayout = WATCHDOG_NOWAYOUT;
>   static unsigned int timeout = MESON_WDT_TIMEOUT;
>
> +struct meson_wdt_data {
> +	unsigned int enable;
> +	unsigned int terminal_count_mask;
> +	unsigned int count_unit;
> +};
> +
> +static struct meson_wdt_data meson6_wdt_data = {
> +	.enable			= BIT(22),
> +	.terminal_count_mask	= 0x3fffff,
> +	.count_unit		= 100000, /* 10 us */
> +};
> +
>   struct meson_wdt_dev {
>   	struct watchdog_device wdt_dev;
>   	void __iomem *wdt_base;
>   	struct notifier_block restart_handler;
> +	const struct meson_wdt_data *data;
>   };
>
>   static int meson_restart_handle(struct notifier_block *this, unsigned long mode,
>   				void *cmd)
>   {
> -	u32 tc_reboot = MESON_WDT_DC_RESET | MESON_WDT_TC_EN;
> +	u32 tc_reboot = MESON_WDT_DC_RESET;
>   	struct meson_wdt_dev *meson_wdt = container_of(this,
>   						       struct meson_wdt_dev,
>   						       restart_handler);
>
> +	tc_reboot |= meson_wdt->data->enable;
> +
>   	while (1) {
>   		writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC);
>   		mdelay(5);
> @@ -80,8 +93,8 @@ static void meson_wdt_change_timeout(struct watchdog_device *wdt_dev,
>   	u32 reg;
>
>   	reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
> -	reg &= ~MESON_WDT_TC_TM_MASK;
> -	reg |= MESON_SEC_TO_TC(timeout);
> +	reg &= ~meson_wdt->data->terminal_count_mask;
> +	reg |= MESON_SEC_TO_TC(timeout, meson_wdt->data->count_unit);
>   	writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
>   }
>
> @@ -102,7 +115,7 @@ static int meson_wdt_stop(struct watchdog_device *wdt_dev)
>   	u32 reg;
>
>   	reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
> -	reg &= ~MESON_WDT_TC_EN;
> +	reg &= ~meson_wdt->data->enable;
>   	writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
>
>   	return 0;
> @@ -117,7 +130,7 @@ static int meson_wdt_start(struct watchdog_device *wdt_dev)
>   	meson_wdt_ping(wdt_dev);
>
>   	reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
> -	reg |= MESON_WDT_TC_EN;
> +	reg |= meson_wdt->data->enable;
>   	writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
>
>   	return 0;
> @@ -138,10 +151,17 @@ static const struct watchdog_ops meson_wdt_ops = {
>   	.set_timeout	= meson_wdt_set_timeout,
>   };
>
> +static const struct of_device_id meson_wdt_dt_ids[] = {
> +	{ .compatible = "amlogic,meson6-wdt", .data = &meson6_wdt_data },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids);
> +
>   static int meson_wdt_probe(struct platform_device *pdev)
>   {
>   	struct resource *res;
>   	struct meson_wdt_dev *meson_wdt;
> +	const struct of_device_id *of_id;
>   	int err;
>
>   	meson_wdt = devm_kzalloc(&pdev->dev, sizeof(*meson_wdt), GFP_KERNEL);
> @@ -153,12 +173,22 @@ static int meson_wdt_probe(struct platform_device *pdev)
>   	if (IS_ERR(meson_wdt->wdt_base))
>   		return PTR_ERR(meson_wdt->wdt_base);
>
> +	of_id = of_match_device(meson_wdt_dt_ids, &pdev->dev);
> +	if (!of_id) {
> +		dev_err(&pdev->dev, "Unable to initialize WDT data\n");
> +		return -ENODEV;
> +	}
> +	meson_wdt->data = of_id->data;
> +
>   	meson_wdt->wdt_dev.parent = &pdev->dev;
>   	meson_wdt->wdt_dev.info = &meson_wdt_info;
>   	meson_wdt->wdt_dev.ops = &meson_wdt_ops;
> -	meson_wdt->wdt_dev.timeout = MESON_WDT_TIMEOUT;
> -	meson_wdt->wdt_dev.max_timeout = MESON_WDT_MAX_TIMEOUT;
> +	meson_wdt->wdt_dev.max_timeout =
> +		meson_wdt->data->terminal_count_mask / meson_wdt->data->count_unit;
>   	meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT;
> +	meson_wdt->wdt_dev.timeout = min_t(unsigned int,
> +					   MESON_WDT_TIMEOUT,
> +					   meson_wdt->wdt_dev.max_timeout);
>
>   	watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt);
>
> @@ -204,12 +234,6 @@ static void meson_wdt_shutdown(struct platform_device *pdev)
>   	meson_wdt_stop(&meson_wdt->wdt_dev);
>   }
>
> -static const struct of_device_id meson_wdt_dt_ids[] = {
> -	{ .compatible = "amlogic,meson6-wdt" },
> -	{ /* sentinel */ }
> -};
> -MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids);
> -
>   static struct platform_driver meson_wdt_driver = {
>   	.probe		= meson_wdt_probe,
>   	.remove		= meson_wdt_remove,
>