Hi,
On Sun, 2019-11-24 at 22:16 -0800, Guenter Roeck wrote:
On Mon, Nov 25, 2019 at 11:03:50AM +0800, Jiaxin Yu wrote:
From: "yong.liang" yong.liang@mediatek.com
Add reset controller API in watchdog driver. Besides watchdog, MTK toprgu module also provide sub-system (eg, audio, camera, codec and connectivity) software reset functionality.
Signed-off-by: yong.liang yong.liang@mediatek.com Signed-off-by: jiaxin.yu jiaxin.yu@mediatek.com Reviewed-by: Yingjoe Chen yingjoe.chen@mediatek.com
drivers/watchdog/Kconfig | 1 + drivers/watchdog/mtk_wdt.c | 111 ++++++++++++++++++++++++++++++++++++- 2 files changed, 111 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..d29484c7940a 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> #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 +61,99 @@ 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 sw_rst_num;
};
+static const struct mtk_wdt_data mt2712_data = {
- .sw_rst_num = MT2712_TOPRGU_SW_RST_NUM,
+};
+static const struct mtk_wdt_data mt8183_data = {
- .sw_rst_num = MT8183_TOPRGU_SW_RST_NUM,
+};
The number of resets can be set in .data directly; there is no need for the structures.
+static int toprgu_reset_assert(struct reset_controller_dev *rcdev,
unsigned long id)+{
- unsigned int tmp;
- unsigned long flags;
- struct mtk_wdt_dev *data =
container_of(rcdev, struct mtk_wdt_dev, rcdev);- spin_lock_irqsave(&data->lock, flags);
- tmp = __raw_readl(data->wdt_base + WDT_SWSYSRST);
I think this should be readl_relaxed() instead. I don't expect this driver will ever be used on a big-endian architecture, but mixing __raw_readl() and writel() does look dangerous.
- 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_deassert(struct reset_controller_dev *rcdev,
unsigned long id)+{
- unsigned int tmp;
- unsigned long flags;
- struct mtk_wdt_dev *data =
container_of(rcdev, struct mtk_wdt_dev, rcdev);- spin_lock_irqsave(&data->lock, flags);
- tmp = __raw_readl(data->wdt_base + WDT_SWSYSRST);
- tmp &= ~BIT(id);
- tmp |= WDT_SWSYS_RST_KEY;
- writel(tmp, data->wdt_base + WDT_SWSYSRST);
- spin_unlock_irqrestore(&data->lock, flags);
- return 0;
+}
There is a lot of duplication in those functions. Only one line is different. I think this is a good example where a helper function with an additional argument indicating set or reset would be helpful.
+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 const struct reset_control_ops toprgu_reset_ops = {
- .assert = toprgu_reset_assert,
- .deassert = toprgu_reset_deassert,
- .reset = toprgu_reset,
+};
+static int toprgu_register_reset_controller(struct platform_device *pdev,
int rst_num)+{
- int ret;
- struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
- spin_lock_init(&mtk_wdt->lock);
- mtk_wdt->rcdev.owner = THIS_MODULE;
- mtk_wdt->rcdev.nr_resets = rst_num;
- mtk_wdt->rcdev.ops = &toprgu_reset_ops;
- mtk_wdt->rcdev.of_node = pdev->dev.of_node;
- ret = reset_controller_register(&mtk_wdt->rcdev);
I see this driver uses devm_kzalloc() below. Should this be devm_reset_controller_register()?
- if (ret != 0)
dev_err(&pdev->dev,"couldn't register wdt reset controller: %d\n", ret);- return ret;
+}
static int mtk_wdt_restart(struct watchdog_device *wdt_dev, unsigned long action, void *data) { @@ -155,6 +254,7 @@ static int mtk_wdt_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct mtk_wdt_dev *mtk_wdt;
struct mtk_wdt_data *wdt_data; int err;
mtk_wdt = devm_kzalloc(dev, sizeof(*mtk_wdt), GFP_KERNEL);
regards Philipp