Hi,
On Thu, 2019-12-12 at 00:22 +0800, Jiaxin Yu wrote:
> From: "yong.liang" <yong.liang@xxxxxxxxxxxx>
>
> Add reset controller API in watchdog driver.
> Besides watchdog, MTK toprgu module alsa provide sub-system (eg, audio,
> camera, codec and connectivity) software reset functionality.
Do any of the listed sub-systems use the reset_control_reset()
functionality? Is there no delay requirement between assert and
deassert? Otherwise it would be safer not to implement the .reset()
operation at all.
>
> Signed-off-by: yong.liang <yong.liang@xxxxxxxxxxxx>
> ---
> drivers/watchdog/Kconfig | 1 +
> drivers/watchdog/mtk_wdt.c | 109 ++++++++++++++++++++++++++++++++++++-
> 2 files changed, 109 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..667380031dfd 100644
> --- a/drivers/watchdog/mtk_wdt.c
> +++ b/drivers/watchdog/mtk_wdt.c
> @@ -9,6 +9,9 @@
> * Based on sunxi_wdt.c
> */
>
> +#include <dt-bindings/reset-controller/mt2712-resets.h>
> +#include <dt-bindings/reset-controller/mt8183-resets.h>
> +#include <linux/delay.h>
> #include <linux/err.h>
> #include <linux/init.h>
> #include <linux/io.h>
> @@ -16,10 +19,12 @@
> #include <linux/module.h>
> #include <linux/moduleparam.h>
> #include <linux/of.h>
> +#include <linux/of_device.h>
> #include <linux/platform_device.h>
> +#include <linux/reset-controller.h>
> +#include <linux/slab.h>
What is this required for?
> #include <linux/types.h>
> #include <linux/watchdog.h>
> -#include <linux/delay.h>
>
> #define WDT_MAX_TIMEOUT 31
> #define WDT_MIN_TIMEOUT 1
> @@ -44,6 +49,9 @@
> #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"
>
> @@ -53,8 +61,97 @@ static unsigned int timeout;
> struct mtk_wdt_dev {
> struct watchdog_device wdt_dev;
> void __iomem *wdt_base;
> + spinlock_t lock; /* protects WDT_SWSYSRST reg */
> + struct reset_controller_dev rcdev;
> +};
> +
> +struct mtk_wdt_data {
> + int infracfg_sw_rst_num;
This is not used at all, better remove it.
> + int toprgu_sw_rst_num;
> +};
> +
> +static const struct mtk_wdt_data mt2712_data = {
> + .toprgu_sw_rst_num = MT2712_TOPRGU_SW_RST_NUM,
> +};
> +
> +static const struct mtk_wdt_data mt8183_data = {
> + .infracfg_sw_rst_num = MT8183_INFRACFG_SW_RST_NUM,
Same as above.
> + .toprgu_sw_rst_num = MT8183_TOPRGU_SW_RST_NUM,
> +};
> +
> +static int toprgu_reset_update(struct reset_controller_dev *rcdev,
> + unsigned long id, bool assert)
> +{
> + unsigned int tmp;
> + unsigned long flags;
> +
This empty line can be removed.
> + struct mtk_wdt_dev *data =
> + container_of(rcdev, struct mtk_wdt_dev, rcdev);
> +
> + spin_lock_irqsave(&data->lock, flags);
> +
> + tmp = readl(data->wdt_base + WDT_SWSYSRST);
> + if (assert)
> + tmp |= BIT(id);
> + else
> + tmp &= ~BIT(id);
> + tmp |= WDT_SWSYS_RST_KEY;
> + writel(tmp, data->wdt_base + WDT_SWSYSRST);
> +
> + spin_unlock_irqrestore(&data->lock, flags);
> +
> + return 0;
> +}
> +
> +static int toprgu_reset_assert(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + return toprgu_reset_update(rcdev, id, true);
> +}
> +
> +static int toprgu_reset_deassert(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + return toprgu_reset_update(rcdev, id, false);
> +}
> +
> +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);
> +}
As mentioned above, is this needed? Does this work for all modules?
Only implement this if you are sure both are true.
regards
Philipp
