2017-04-06 12:21:15

by Yannick FERTRE

[permalink] [raw]
Subject: [PATCH v5 0/5] STM32 Independent watchdog

Version 5:
- Update bindings (add field timeout-sec)
- Update driver (rework start, rework settings & remove max_timeout)

Version 4:
- Update bindings (iwdg > watchdog)
- Update typo
- Update commit header
- remove gerrit tags
- Update driver (remove unnecessary tests) a add watchdog_init_timeout

Version 3:
- Update typo into bindings file
- Reorder node in devicetree (ordering by address)
- Remove unnecessary lines in commits

Version 2:
- Add commit messages

Version 1:
- Initial commit

The purpose of this set of patches is to add a new watchdog driver for
stm32f429.
This driver was developed and tested on evaluation board stm32429i.

Yannick Fertre (5):
dt-bindings: watchdog: Document STM32 IWDG bindings
drivers: watchdog: Add STM32 IWDG driver
ARM: dts: stm32: Add watchdog support for STM32F429 SoC
ARM: dts: stm32: Add watchdog support for STM32F429 eval board
ARM: configs: stm32: Add watchdog support in STM32 defconfig

.../devicetree/bindings/watchdog/st,stm32-iwdg.txt | 19 ++
arch/arm/boot/dts/stm32429i-eval.dts | 5 +
arch/arm/boot/dts/stm32f429.dtsi | 9 +-
arch/arm/configs/stm32_defconfig | 1 +
drivers/watchdog/Kconfig | 12 +
drivers/watchdog/Makefile | 1 +
drivers/watchdog/stm32_iwdg.c | 253 +++++++++++++++++++++
7 files changed, 299 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/watchdog/st,stm32-iwdg.txt
create mode 100644 drivers/watchdog/stm32_iwdg.c

--
1.9.1


2017-04-06 12:21:04

by Yannick FERTRE

[permalink] [raw]
Subject: [PATCH v5 4/5] ARM: dts: stm32: Add watchdog support for STM32F429 eval board

This patch adds watchdog support for STM32x9I-Eval board.

Signed-off-by: Yannick Fertre <[email protected]>
---
arch/arm/boot/dts/stm32429i-eval.dts | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/dts/stm32429i-eval.dts b/arch/arm/boot/dts/stm32429i-eval.dts
index 6e4b42a..ff29980 100644
--- a/arch/arm/boot/dts/stm32429i-eval.dts
+++ b/arch/arm/boot/dts/stm32429i-eval.dts
@@ -144,6 +144,11 @@
};
};

+&iwdg {
+ status = "okay";
+ timeout-sec = <32>;
+};
+
&adc {
pinctrl-names = "default";
pinctrl-0 = <&adc3_in8_pin>;
--
1.9.1

2017-04-06 12:21:24

by Yannick FERTRE

[permalink] [raw]
Subject: [PATCH v5 5/5] ARM: configs: stm32: Add watchdog support in STM32 defconfig

This patch adds STM32 watchdog support in stm32_defconfig file

Signed-off-by: Yannick Fertre <[email protected]>
---
arch/arm/configs/stm32_defconfig | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/stm32_defconfig b/arch/arm/configs/stm32_defconfig
index 29ac5a4..1fb901c 100644
--- a/arch/arm/configs/stm32_defconfig
+++ b/arch/arm/configs/stm32_defconfig
@@ -51,6 +51,7 @@ CONFIG_I2C=y
CONFIG_I2C_CHARDEV=y
CONFIG_I2C_STM32F4=y
# CONFIG_HWMON is not set
+CONFIG_WATCHDOG=y
CONFIG_REGULATOR=y
CONFIG_REGULATOR_FIXED_VOLTAGE=y
# CONFIG_USB_SUPPORT is not set
--
1.9.1

2017-04-06 12:21:35

by Yannick FERTRE

[permalink] [raw]
Subject: [PATCH v5 3/5] ARM: dts: stm32: Add watchdog support for STM32F429 SoC

Add watchdog into DT for stm32f429 family.

Signed-off-by: Yannick FERTRE <[email protected]>
---
arch/arm/boot/dts/stm32f429.dtsi | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/stm32f429.dtsi b/arch/arm/boot/dts/stm32f429.dtsi
index 89327d6..d84dd44 100644
--- a/arch/arm/boot/dts/stm32f429.dtsi
+++ b/arch/arm/boot/dts/stm32f429.dtsi
@@ -64,7 +64,7 @@
clock-frequency = <32768>;
};

- clk-lsi {
+ clk_lsi: clk-lsi {
#clock-cells = <0>;
compatible = "fixed-clock";
clock-frequency = <32000>;
@@ -306,6 +306,13 @@
status = "disabled";
};

+ iwdg: watchdog@40003000 {
+ compatible = "st,stm32-iwdg";
+ reg = <0x40003000 0x400>;
+ clocks = <&clk_lsi>;
+ status = "disabled";
+ };
+
usart2: serial@40004400 {
compatible = "st,stm32-usart", "st,stm32-uart";
reg = <0x40004400 0x400>;
--
1.9.1

2017-04-06 12:21:46

by Yannick FERTRE

[permalink] [raw]
Subject: [PATCH v5 1/5] dt-bindings: watchdog: Document STM32 IWDG bindings

This adds documentation of device tree bindings for the STM32 IWDG
(Independent WatchDoG).

Signed-off-by: Yannick Fertre <[email protected]>
---
.../devicetree/bindings/watchdog/st,stm32-iwdg.txt | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
create mode 100644 Documentation/devicetree/bindings/watchdog/st,stm32-iwdg.txt

diff --git a/Documentation/devicetree/bindings/watchdog/st,stm32-iwdg.txt b/Documentation/devicetree/bindings/watchdog/st,stm32-iwdg.txt
new file mode 100644
index 0000000..cc13b10a
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/st,stm32-iwdg.txt
@@ -0,0 +1,19 @@
+STM32 Independent WatchDoG (IWDG)
+---------------------------------
+
+Required properties:
+- compatible: "st,stm32-iwdg"
+- reg: physical base address and length of the registers set for the device
+- clocks: must contain a single entry describing the clock input
+
+Optional Properties:
+- timeout-sec: Watchdog timeout value in seconds.
+
+Example:
+
+iwdg: watchdog@40003000 {
+ compatible = "st,stm32-iwdg";
+ reg = <0x40003000 0x400>;
+ clocks = <&clk_lsi>;
+ timeout-sec = <32>;
+};
--
1.9.1

2017-04-06 12:22:07

by Yannick FERTRE

[permalink] [raw]
Subject: [PATCH v5 2/5] drivers: watchdog: Add STM32 IWDG driver

This patch adds IWDG (Independent WatchDoG) support for STM32 platform.

Signed-off-by: Yannick FERTRE <[email protected]>
---
drivers/watchdog/Kconfig | 12 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/stm32_iwdg.c | 253 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 266 insertions(+)
create mode 100644 drivers/watchdog/stm32_iwdg.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 52a70ee..d014deb 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -744,6 +744,18 @@ config ZX2967_WATCHDOG
To compile this driver as a module, choose M here: the
module will be called zx2967_wdt.

+config STM32_WATCHDOG
+ tristate "STM32 Independent WatchDoG (IWDG) support"
+ depends on ARCH_STM32
+ select WATCHDOG_CORE
+ default y
+ help
+ Say Y here to include support for the watchdog timer
+ in stm32 SoCs.
+
+ To compile this driver as a module, choose M here: the
+ module will be called stm32_iwdg.
+
# AVR32 Architecture

config AT32AP700X_WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index a2126e2..a35e423 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -84,6 +84,7 @@ obj-$(CONFIG_ATLAS7_WATCHDOG) += atlas7_wdt.o
obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o
obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o
obj-$(CONFIG_ZX2967_WATCHDOG) += zx2967_wdt.o
+obj-$(CONFIG_STM32_WATCHDOG) += stm32_iwdg.o

# AVR32 Architecture
obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
diff --git a/drivers/watchdog/stm32_iwdg.c b/drivers/watchdog/stm32_iwdg.c
new file mode 100644
index 0000000..6c501b7
--- /dev/null
+++ b/drivers/watchdog/stm32_iwdg.c
@@ -0,0 +1,253 @@
+/*
+ * Driver for STM32 Independent Watchdog
+ *
+ * Copyright (C) Yannick Fertre 2017
+ * Author: Yannick Fertre <[email protected]>
+ *
+ * This driver is based on tegra_wdt.c
+ *
+ * License terms: GNU General Public License (GPL), version 2
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+/* IWDG registers */
+#define IWDG_KR 0x00 /* Key register */
+#define IWDG_PR 0x04 /* Prescaler Register */
+#define IWDG_RLR 0x08 /* ReLoad Register */
+#define IWDG_SR 0x0C /* Status Register */
+#define IWDG_WINR 0x10 /* Windows Register */
+
+/* IWDG_KR register bit mask */
+#define KR_KEY_RELOAD 0xAAAA /* reload counter enable */
+#define KR_KEY_ENABLE 0xCCCC /* peripheral enable */
+#define KR_KEY_EWA 0x5555 /* write access enable */
+#define KR_KEY_DWA 0x0000 /* write access disable */
+
+/* IWDG_PR register bit values */
+#define PR_4 0x00 /* prescaler set to 4 */
+#define PR_8 0x01 /* prescaler set to 8 */
+#define PR_16 0x02 /* prescaler set to 16 */
+#define PR_32 0x03 /* prescaler set to 32 */
+#define PR_64 0x04 /* prescaler set to 64 */
+#define PR_128 0x05 /* prescaler set to 128 */
+#define PR_256 0x06 /* prescaler set to 256 */
+
+/* IWDG_RLR register values */
+#define RLR_MIN 0x07C /* min value supported by reload register */
+#define RLR_MAX 0xFFF /* max value supported by reload register */
+
+/* IWDG_SR register bit mask */
+#define FLAG_PVU BIT(0) /* Watchdog prescaler value update */
+#define FLAG_RVU BIT(1) /* Watchdog counter reload value update */
+
+/* set timeout to 100000 us */
+#define TIMEOUT_US 100000
+#define SLEEP_US 1000
+
+struct stm32_iwdg {
+ struct watchdog_device wdd;
+ void __iomem *regs;
+ struct clk *clk;
+ unsigned int rate;
+};
+
+static inline u32 reg_read(void __iomem *base, u32 reg)
+{
+ return readl_relaxed(base + reg);
+}
+
+static inline void reg_write(void __iomem *base, u32 reg, u32 val)
+{
+ writel_relaxed(val, base + reg);
+}
+
+static int stm32_iwdg_start(struct watchdog_device *wdd)
+{
+ struct stm32_iwdg *wdt = watchdog_get_drvdata(wdd);
+ u32 val = FLAG_PVU | FLAG_RVU;
+ u32 reload;
+ int ret;
+
+ dev_dbg(wdd->parent, "%s\n", __func__);
+
+ /* prescaler fixed to 256 */
+ reload = clamp_t(unsigned int, ((wdd->timeout * wdt->rate) / 256) - 1,
+ RLR_MIN, RLR_MAX);
+
+ /* enable write access */
+ reg_write(wdt->regs, IWDG_KR, KR_KEY_EWA);
+
+ /* set prescaler & reload registers */
+ reg_write(wdt->regs, IWDG_PR, PR_256); /* prescaler fix to 256 */
+ reg_write(wdt->regs, IWDG_RLR, reload);
+ reg_write(wdt->regs, IWDG_KR, KR_KEY_ENABLE);
+
+ /* wait for the registers to be updated (max 100ms) */
+ ret = readl_relaxed_poll_timeout(wdt->regs + IWDG_SR, val,
+ !(val & (FLAG_PVU | FLAG_RVU)),
+ SLEEP_US, TIMEOUT_US);
+ if (ret) {
+ dev_err(wdd->parent,
+ "Fail to set prescaler or reload registers\n");
+ return ret;
+ }
+
+ /* reload watchdog */
+ reg_write(wdt->regs, IWDG_KR, KR_KEY_RELOAD);
+
+ return 0;
+}
+
+static int stm32_iwdg_ping(struct watchdog_device *wdd)
+{
+ struct stm32_iwdg *wdt = watchdog_get_drvdata(wdd);
+
+ dev_dbg(wdd->parent, "%s\n", __func__);
+
+ /* reload watchdog */
+ reg_write(wdt->regs, IWDG_KR, KR_KEY_RELOAD);
+
+ return 0;
+}
+
+static int stm32_iwdg_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ dev_dbg(wdd->parent, "%s timeout: %d sec\n", __func__, timeout);
+
+ wdd->timeout = timeout;
+
+ if (watchdog_active(wdd))
+ return stm32_iwdg_start(wdd);
+
+ return 0;
+}
+
+static const struct watchdog_info stm32_iwdg_info = {
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_MAGICCLOSE |
+ WDIOF_KEEPALIVEPING,
+ .identity = "STM32 Independent Watchdog",
+};
+
+static struct watchdog_ops stm32_iwdg_ops = {
+ .owner = THIS_MODULE,
+ .start = stm32_iwdg_start,
+ .ping = stm32_iwdg_ping,
+ .set_timeout = stm32_iwdg_set_timeout,
+};
+
+static int stm32_iwdg_probe(struct platform_device *pdev)
+{
+ struct watchdog_device *wdd;
+ struct stm32_iwdg *wdt;
+ struct resource *res;
+ void __iomem *regs;
+ struct clk *clk;
+ int ret;
+
+ /* This is the timer base. */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(regs)) {
+ dev_err(&pdev->dev, "Could not get resource\n");
+ return PTR_ERR(regs);
+ }
+
+ clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "Unable to get clock\n");
+ return PTR_ERR(clk);
+ }
+
+ ret = clk_prepare_enable(clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Unable to prepare clock %p\n", clk);
+ return ret;
+ }
+
+ /*
+ * Allocate our watchdog driver data, which has the
+ * struct watchdog_device nested within it.
+ */
+ wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
+ if (!wdt) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ /* Initialize struct stm32_iwdg. */
+ wdt->regs = regs;
+ wdt->clk = clk;
+ wdt->rate = clk_get_rate(clk);
+
+ /* Initialize struct watchdog_device. */
+ wdd = &wdt->wdd;
+ wdd->info = &stm32_iwdg_info;
+ wdd->ops = &stm32_iwdg_ops;
+ wdd->min_timeout = ((RLR_MIN + 1) * 256) / wdt->rate;
+ wdd->max_hw_heartbeat_ms = ((RLR_MAX + 1) * 256 * 1000) / wdt->rate;
+ wdd->parent = &pdev->dev;
+
+ watchdog_set_drvdata(wdd, wdt);
+ watchdog_set_nowayout(wdd, WATCHDOG_NOWAYOUT);
+
+ ret = watchdog_init_timeout(wdd, 0, &pdev->dev);
+ if (ret)
+ dev_warn(&pdev->dev,
+ "unable to set timeout value, using default\n");
+
+ ret = watchdog_register_device(wdd);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register watchdog device\n");
+ goto err;
+ }
+
+ platform_set_drvdata(pdev, wdt);
+
+ return 0;
+err:
+ clk_disable_unprepare(clk);
+
+ return ret;
+}
+
+static int stm32_iwdg_remove(struct platform_device *pdev)
+{
+ struct stm32_iwdg *wdt = platform_get_drvdata(pdev);
+
+ watchdog_unregister_device(&wdt->wdd);
+ clk_disable_unprepare(wdt->clk);
+
+ return 0;
+}
+
+static const struct of_device_id stm32_iwdg_of_match[] = {
+ { .compatible = "st,stm32-iwdg" },
+ { /* end node */ }
+};
+MODULE_DEVICE_TABLE(of, stm32_iwdg_of_match);
+
+static struct platform_driver stm32_iwdg_driver = {
+ .probe = stm32_iwdg_probe,
+ .remove = stm32_iwdg_remove,
+ .driver = {
+ .name = "iwdg",
+ .of_match_table = stm32_iwdg_of_match,
+ },
+};
+module_platform_driver(stm32_iwdg_driver);
+
+MODULE_AUTHOR("Yannick Fertre <[email protected]>");
+MODULE_DESCRIPTION("STMicroelectronics STM32 Independent Watchdog Driver");
+MODULE_LICENSE("GPL v2");
--
1.9.1

2017-04-10 18:25:53

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH v5 1/5] dt-bindings: watchdog: Document STM32 IWDG bindings

On Thu, Apr 06, 2017 at 02:19:24PM +0200, Yannick Fertre wrote:
> This adds documentation of device tree bindings for the STM32 IWDG
> (Independent WatchDoG).
>
> Signed-off-by: Yannick Fertre <[email protected]>
> ---
> .../devicetree/bindings/watchdog/st,stm32-iwdg.txt | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/watchdog/st,stm32-iwdg.txt

Acked-by: Rob Herring <[email protected]>

2017-04-17 01:11:16

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH v5 2/5] drivers: watchdog: Add STM32 IWDG driver

On 04/06/2017 05:19 AM, Yannick Fertre wrote:
> This patch adds IWDG (Independent WatchDoG) support for STM32 platform.
>
> Signed-off-by: Yannick FERTRE <[email protected]>

Reviewed-by: Guenter Roeck <[email protected]>

> ---
> drivers/watchdog/Kconfig | 12 ++
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/stm32_iwdg.c | 253 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 266 insertions(+)
> create mode 100644 drivers/watchdog/stm32_iwdg.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 52a70ee..d014deb 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -744,6 +744,18 @@ config ZX2967_WATCHDOG
> To compile this driver as a module, choose M here: the
> module will be called zx2967_wdt.
>
> +config STM32_WATCHDOG
> + tristate "STM32 Independent WatchDoG (IWDG) support"
> + depends on ARCH_STM32
> + select WATCHDOG_CORE
> + default y
> + help
> + Say Y here to include support for the watchdog timer
> + in stm32 SoCs.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called stm32_iwdg.
> +
> # AVR32 Architecture
>
> config AT32AP700X_WDT
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index a2126e2..a35e423 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -84,6 +84,7 @@ obj-$(CONFIG_ATLAS7_WATCHDOG) += atlas7_wdt.o
> obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o
> obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o
> obj-$(CONFIG_ZX2967_WATCHDOG) += zx2967_wdt.o
> +obj-$(CONFIG_STM32_WATCHDOG) += stm32_iwdg.o
>
> # AVR32 Architecture
> obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
> diff --git a/drivers/watchdog/stm32_iwdg.c b/drivers/watchdog/stm32_iwdg.c
> new file mode 100644
> index 0000000..6c501b7
> --- /dev/null
> +++ b/drivers/watchdog/stm32_iwdg.c
> @@ -0,0 +1,253 @@
> +/*
> + * Driver for STM32 Independent Watchdog
> + *
> + * Copyright (C) Yannick Fertre 2017
> + * Author: Yannick Fertre <[email protected]>
> + *
> + * This driver is based on tegra_wdt.c
> + *
> + * License terms: GNU General Public License (GPL), version 2
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/watchdog.h>
> +
> +/* IWDG registers */
> +#define IWDG_KR 0x00 /* Key register */
> +#define IWDG_PR 0x04 /* Prescaler Register */
> +#define IWDG_RLR 0x08 /* ReLoad Register */
> +#define IWDG_SR 0x0C /* Status Register */
> +#define IWDG_WINR 0x10 /* Windows Register */
> +
> +/* IWDG_KR register bit mask */
> +#define KR_KEY_RELOAD 0xAAAA /* reload counter enable */
> +#define KR_KEY_ENABLE 0xCCCC /* peripheral enable */
> +#define KR_KEY_EWA 0x5555 /* write access enable */
> +#define KR_KEY_DWA 0x0000 /* write access disable */
> +
> +/* IWDG_PR register bit values */
> +#define PR_4 0x00 /* prescaler set to 4 */
> +#define PR_8 0x01 /* prescaler set to 8 */
> +#define PR_16 0x02 /* prescaler set to 16 */
> +#define PR_32 0x03 /* prescaler set to 32 */
> +#define PR_64 0x04 /* prescaler set to 64 */
> +#define PR_128 0x05 /* prescaler set to 128 */
> +#define PR_256 0x06 /* prescaler set to 256 */
> +
> +/* IWDG_RLR register values */
> +#define RLR_MIN 0x07C /* min value supported by reload register */
> +#define RLR_MAX 0xFFF /* max value supported by reload register */
> +
> +/* IWDG_SR register bit mask */
> +#define FLAG_PVU BIT(0) /* Watchdog prescaler value update */
> +#define FLAG_RVU BIT(1) /* Watchdog counter reload value update */
> +
> +/* set timeout to 100000 us */
> +#define TIMEOUT_US 100000
> +#define SLEEP_US 1000
> +
> +struct stm32_iwdg {
> + struct watchdog_device wdd;
> + void __iomem *regs;
> + struct clk *clk;
> + unsigned int rate;
> +};
> +
> +static inline u32 reg_read(void __iomem *base, u32 reg)
> +{
> + return readl_relaxed(base + reg);
> +}
> +
> +static inline void reg_write(void __iomem *base, u32 reg, u32 val)
> +{
> + writel_relaxed(val, base + reg);
> +}
> +
> +static int stm32_iwdg_start(struct watchdog_device *wdd)
> +{
> + struct stm32_iwdg *wdt = watchdog_get_drvdata(wdd);
> + u32 val = FLAG_PVU | FLAG_RVU;
> + u32 reload;
> + int ret;
> +
> + dev_dbg(wdd->parent, "%s\n", __func__);
> +
> + /* prescaler fixed to 256 */
> + reload = clamp_t(unsigned int, ((wdd->timeout * wdt->rate) / 256) - 1,
> + RLR_MIN, RLR_MAX);
> +
> + /* enable write access */
> + reg_write(wdt->regs, IWDG_KR, KR_KEY_EWA);
> +
> + /* set prescaler & reload registers */
> + reg_write(wdt->regs, IWDG_PR, PR_256); /* prescaler fix to 256 */
> + reg_write(wdt->regs, IWDG_RLR, reload);
> + reg_write(wdt->regs, IWDG_KR, KR_KEY_ENABLE);
> +
> + /* wait for the registers to be updated (max 100ms) */
> + ret = readl_relaxed_poll_timeout(wdt->regs + IWDG_SR, val,
> + !(val & (FLAG_PVU | FLAG_RVU)),
> + SLEEP_US, TIMEOUT_US);
> + if (ret) {
> + dev_err(wdd->parent,
> + "Fail to set prescaler or reload registers\n");
> + return ret;
> + }
> +
> + /* reload watchdog */
> + reg_write(wdt->regs, IWDG_KR, KR_KEY_RELOAD);
> +
> + return 0;
> +}
> +
> +static int stm32_iwdg_ping(struct watchdog_device *wdd)
> +{
> + struct stm32_iwdg *wdt = watchdog_get_drvdata(wdd);
> +
> + dev_dbg(wdd->parent, "%s\n", __func__);
> +
> + /* reload watchdog */
> + reg_write(wdt->regs, IWDG_KR, KR_KEY_RELOAD);
> +
> + return 0;
> +}
> +
> +static int stm32_iwdg_set_timeout(struct watchdog_device *wdd,
> + unsigned int timeout)
> +{
> + dev_dbg(wdd->parent, "%s timeout: %d sec\n", __func__, timeout);
> +
> + wdd->timeout = timeout;
> +
> + if (watchdog_active(wdd))
> + return stm32_iwdg_start(wdd);
> +
> + return 0;
> +}
> +
> +static const struct watchdog_info stm32_iwdg_info = {
> + .options = WDIOF_SETTIMEOUT |
> + WDIOF_MAGICCLOSE |
> + WDIOF_KEEPALIVEPING,
> + .identity = "STM32 Independent Watchdog",
> +};
> +
> +static struct watchdog_ops stm32_iwdg_ops = {
> + .owner = THIS_MODULE,
> + .start = stm32_iwdg_start,
> + .ping = stm32_iwdg_ping,
> + .set_timeout = stm32_iwdg_set_timeout,
> +};
> +
> +static int stm32_iwdg_probe(struct platform_device *pdev)
> +{
> + struct watchdog_device *wdd;
> + struct stm32_iwdg *wdt;
> + struct resource *res;
> + void __iomem *regs;
> + struct clk *clk;
> + int ret;
> +
> + /* This is the timer base. */
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + regs = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(regs)) {
> + dev_err(&pdev->dev, "Could not get resource\n");
> + return PTR_ERR(regs);
> + }
> +
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(clk)) {
> + dev_err(&pdev->dev, "Unable to get clock\n");
> + return PTR_ERR(clk);
> + }
> +
> + ret = clk_prepare_enable(clk);
> + if (ret) {
> + dev_err(&pdev->dev, "Unable to prepare clock %p\n", clk);
> + return ret;
> + }
> +
> + /*
> + * Allocate our watchdog driver data, which has the
> + * struct watchdog_device nested within it.
> + */
> + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
> + if (!wdt) {
> + ret = -ENOMEM;
> + goto err;
> + }
> +
> + /* Initialize struct stm32_iwdg. */
> + wdt->regs = regs;
> + wdt->clk = clk;
> + wdt->rate = clk_get_rate(clk);
> +
> + /* Initialize struct watchdog_device. */
> + wdd = &wdt->wdd;
> + wdd->info = &stm32_iwdg_info;
> + wdd->ops = &stm32_iwdg_ops;
> + wdd->min_timeout = ((RLR_MIN + 1) * 256) / wdt->rate;
> + wdd->max_hw_heartbeat_ms = ((RLR_MAX + 1) * 256 * 1000) / wdt->rate;
> + wdd->parent = &pdev->dev;
> +
> + watchdog_set_drvdata(wdd, wdt);
> + watchdog_set_nowayout(wdd, WATCHDOG_NOWAYOUT);
> +
> + ret = watchdog_init_timeout(wdd, 0, &pdev->dev);
> + if (ret)
> + dev_warn(&pdev->dev,
> + "unable to set timeout value, using default\n");
> +
> + ret = watchdog_register_device(wdd);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to register watchdog device\n");
> + goto err;
> + }
> +
> + platform_set_drvdata(pdev, wdt);
> +
> + return 0;
> +err:
> + clk_disable_unprepare(clk);
> +
> + return ret;
> +}
> +
> +static int stm32_iwdg_remove(struct platform_device *pdev)
> +{
> + struct stm32_iwdg *wdt = platform_get_drvdata(pdev);
> +
> + watchdog_unregister_device(&wdt->wdd);
> + clk_disable_unprepare(wdt->clk);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id stm32_iwdg_of_match[] = {
> + { .compatible = "st,stm32-iwdg" },
> + { /* end node */ }
> +};
> +MODULE_DEVICE_TABLE(of, stm32_iwdg_of_match);
> +
> +static struct platform_driver stm32_iwdg_driver = {
> + .probe = stm32_iwdg_probe,
> + .remove = stm32_iwdg_remove,
> + .driver = {
> + .name = "iwdg",
> + .of_match_table = stm32_iwdg_of_match,
> + },
> +};
> +module_platform_driver(stm32_iwdg_driver);
> +
> +MODULE_AUTHOR("Yannick Fertre <[email protected]>");
> +MODULE_DESCRIPTION("STMicroelectronics STM32 Independent Watchdog Driver");
> +MODULE_LICENSE("GPL v2");
>

2017-06-12 10:08:51

by Alexandre Torgue

[permalink] [raw]
Subject: Re: [PATCH v5 0/5] STM32 Independent watchdog

Hi Yannick

On 04/06/2017 02:19 PM, Yannick Fertre wrote:
> Version 5:
> - Update bindings (add field timeout-sec)
> - Update driver (rework start, rework settings & remove max_timeout)
>
> Version 4:
> - Update bindings (iwdg > watchdog)
> - Update typo
> - Update commit header
> - remove gerrit tags
> - Update driver (remove unnecessary tests) a add watchdog_init_timeout
>
> Version 3:
> - Update typo into bindings file
> - Reorder node in devicetree (ordering by address)
> - Remove unnecessary lines in commits
>
> Version 2:
> - Add commit messages
>
> Version 1:
> - Initial commit
>
> The purpose of this set of patches is to add a new watchdog driver for
> stm32f429.
> This driver was developed and tested on evaluation board stm32429i.
>
> Yannick Fertre (5):
> dt-bindings: watchdog: Document STM32 IWDG bindings
> drivers: watchdog: Add STM32 IWDG driver
> ARM: dts: stm32: Add watchdog support for STM32F429 SoC
> ARM: dts: stm32: Add watchdog support for STM32F429 eval board
> ARM: configs: stm32: Add watchdog support in STM32 defconfig
>
> .../devicetree/bindings/watchdog/st,stm32-iwdg.txt | 19 ++
> arch/arm/boot/dts/stm32429i-eval.dts | 5 +
> arch/arm/boot/dts/stm32f429.dtsi | 9 +-
> arch/arm/configs/stm32_defconfig | 1 +
> drivers/watchdog/Kconfig | 12 +
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/stm32_iwdg.c | 253 +++++++++++++++++++++
> 7 files changed, 299 insertions(+), 1 deletion(-)
> create mode 100644 Documentation/devicetree/bindings/watchdog/st,stm32-iwdg.txt
> create mode 100644 drivers/watchdog/stm32_iwdg.c
>

Patches 3&4 applied on stm32-dt-for-v4.13
Patch 5 applied on stm32-defconfig-for-v4.13

regards
Alex