On 9/27/19 3:31 AM, Jiaxin Yu wrote:
From: "yong.liang" yong.liang@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@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;
"dev_comp" suggests that this would be a device name. In practice, the only value there is sw_rst_num, and the value is only used in toprgu_register_reset_controller(). Might as well pass it as argument and drop this pointer.
+};
+struct mtk_wdt_compatible {
- int sw_rst_num;
+};
"compatible" is an odd name for this structure. I would suggest to select a more common name such as "mtk_wdt_data".
+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);
Unless there is additional synchronization elsewhere, parallel calls to the -> assert, and ->reset callbacks may result in the reset being deasserted while at least one caller (the one who called the ->assert function) believes that it is still asserted.
[ ... and if there _is_ additional synchronization elsewhere, the local spinlock would be unnecessary ]
+}
+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)
Since there is only one well defined offset, it seems unnecessary to pass regofs as parameter.
+{
- 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);
Duplicate, and not really needed. Just pass sw_rst_num as argument.
- 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);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,
Please no such magic numbers. This should be a define in an include file.
+};
- static const struct of_device_id mtk_wdt_dt_ids[] = {
- { .compatible = "mediatek,mt8183-wdt", .data = &mt8183_compat }, { .compatible = "mediatek,mt6589-wdt" }, { /* sentinel */ } };