On 9/27/19 3:31 AM, Jiaxin Yu wrote:
From: "yong.liang" <yong.liang@xxxxxxxxxxxx>
Provide assert/deassert/reset API in watchdog driver.
Register reset controller for toprgu device in watchdog probe.
Signed-off-by: yong.liang <yong.liang@xxxxxxxxxxxx>
---
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 */ }
};
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