Quantcast

[RFC PATCH 0/3] watchdog: Add Amlogic Meson GXBB Watchdog Timer driver

classic Classic list List threaded Threaded
7 messages Options
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

[RFC PATCH 0/3] watchdog: Add Amlogic Meson GXBB Watchdog Timer driver

Neil Armstrong-3
Adds support for the Amlogic Meson GXBB SoC Watchdog Timer.
It differs from the meson6/meson8b HW, so need for a separate driver.
The HW provides a divider capable of having a 1ms timebase thus simplifying
the counter update.
The restart call is not provided even if the HW is capable of triggering a
system reset immediately because of the PSCI firmare having such functionnality.

Neil Armstrong (3):
  watchdog: Add Meson GXBB Watchdog Driver
  dt-bindings: watchdog: Add Meson GXBB Watchdog bindings
  ARM64: dts: amlogic: meson-gxbb: Add watchdog node

 .../bindings/watchdog/meson-gxbb-wdt.txt           |  13 +
 arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi        |   6 +
 drivers/watchdog/Makefile                          |   1 +
 drivers/watchdog/meson_gxbb_wdt.c                  | 287 +++++++++++++++++++++
 4 files changed, 307 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/watchdog/meson-gxbb-wdt.txt
 create mode 100644 drivers/watchdog/meson_gxbb_wdt.c

--
2.7.0

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

[RFC PATCH 1/3] watchdog: Add Meson GXBB Watchdog Driver

Neil Armstrong-3
Add watchdog specific driver for Amlogic Meson GXBB SoC.

Signed-off-by: Neil Armstrong <[hidden email]>
---
 drivers/watchdog/Makefile         |   1 +
 drivers/watchdog/meson_gxbb_wdt.c | 287 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 288 insertions(+)
 create mode 100644 drivers/watchdog/meson_gxbb_wdt.c

diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 9bde095..7679d93 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -68,6 +68,7 @@ obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o
 obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o
 obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o
 obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o
+obj-$(CONFIG_MESON_WATCHDOG) += meson_gxbb_wdt.o
 obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o
 obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o
 obj-$(CONFIG_LPC18XX_WATCHDOG) += lpc18xx_wdt.o
diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
new file mode 100644
index 0000000..0c7c0d9
--- /dev/null
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -0,0 +1,287 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright (c) 2016 BayLibre, SAS.
+ * Author: Neil Armstrong <[hidden email]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ * The full GNU General Public License is included in this distribution
+ * in the file called COPYING.
+ *
+ * BSD LICENSE
+ *
+ * Copyright (c) 2016 BayLibre, SAS.
+ * Author: Neil Armstrong <[hidden email]>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in
+ *     the documentation and/or other materials provided with the
+ *     distribution.
+ *   * Neither the name of Intel Corporation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+
+#define DEFAULT_TIMEOUT 10 /* seconds */
+
+#define GXBB_WDT_CTRL_REG 0x0
+#define GXBB_WDT_CTRL1_REG 0x4
+#define GXBB_WDT_TCNT_REG 0x8
+#define GXBB_WDT_RSET_REG 0xc
+
+#define GXBB_WDT_CTRL_EE_RESET_NOW BIT(26)
+
+#define GXBB_WDT_CTRL_CLKDIV_EN BIT(25)
+#define GXBB_WDT_CTRL_CLK_EN BIT(24)
+#define GXBB_WDT_CTRL_IRQ_EN BIT(23)
+#define GXBB_WDT_CTRL_EE_RESET BIT(21)
+#define GXBB_WDT_CTRL_XTAL_SEL (0)
+#define GXBB_WDT_CTRL_CLK81_SEL BIT(19)
+#define GXBB_WDT_CTRL_EN BIT(18)
+#define GXBB_WDT_CTRL_DIV_MASK (BIT(18)-1)
+
+#define GXBB_WDT_CTRL1_GPIO_PULSE BIT(17)
+#define GXBB_WDT_CTRL1_GPIO_POL_RESET_0 BIT(16)
+#define GXBB_WDT_CTRL1_GPIO_POL_RESET_1 (0)
+#define GXBB_WDT_CTRL1_GPIO_PULSE_CNT (BIT(16)-1)
+
+#define GXBB_WDT_TCNT_SETUP_MASK (BIT(16)-1)
+#define GXBB_WDT_TCNT_CNT_SHIFT 16
+
+struct meson_gxbb_wdt {
+ void __iomem *reg_base;
+ struct watchdog_device wdt_dev;
+ struct clk *clk;
+};
+
+int meson_gxbb_wdt_start(struct watchdog_device *wdt_dev)
+{
+ struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
+
+ writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN,
+ data->reg_base + GXBB_WDT_CTRL_REG);
+
+ return 0;
+}
+
+int meson_gxbb_wdt_stop(struct watchdog_device *wdt_dev)
+{
+ struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
+
+ writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN,
+ data->reg_base + GXBB_WDT_CTRL_REG);
+
+ return 0;
+}
+
+unsigned int meson_gxbb_wdt_status(struct watchdog_device *wdt_dev)
+{
+ struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
+
+ return !!(readl(data->reg_base + GXBB_WDT_CTRL_REG) & GXBB_WDT_CTRL_EN);
+}
+
+int meson_gxbb_wdt_ping(struct watchdog_device *wdt_dev)
+{
+ struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
+
+ writel(0, data->reg_base + GXBB_WDT_RSET_REG);
+
+ return 0;
+}
+
+int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev,
+       unsigned int timeout)
+{
+ struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
+
+ if (watchdog_active(wdt_dev))
+ meson_gxbb_wdt_stop(wdt_dev);
+
+ meson_gxbb_wdt_ping(wdt_dev);
+
+ writel(timeout*1000, data->reg_base + GXBB_WDT_TCNT_REG);
+
+ if (watchdog_active(wdt_dev))
+ meson_gxbb_wdt_start(wdt_dev);
+
+ return 0;
+}
+
+unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev)
+{
+ struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
+ unsigned long reg;
+
+ reg = readl(data->reg_base + GXBB_WDT_TCNT_REG);
+
+ return ((reg >> GXBB_WDT_TCNT_CNT_SHIFT)-
+ (reg & GXBB_WDT_TCNT_SETUP_MASK)) / 1000;
+}
+
+static const struct watchdog_ops meson_gxbb_wdt_ops = {
+ .start = meson_gxbb_wdt_start,
+ .stop = meson_gxbb_wdt_stop,
+ .status = meson_gxbb_wdt_status,
+ .ping = meson_gxbb_wdt_ping,
+ .set_timeout = meson_gxbb_wdt_set_timeout,
+ .get_timeleft = meson_gxbb_wdt_get_timeleft,
+};
+
+static const struct watchdog_info meson_gxbb_wdt_info = {
+ .identity = "meson-gxbb-wdt",
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+};
+
+static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev)
+{
+ struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
+
+ if (watchdog_active(&data->wdt_dev))
+ meson_gxbb_wdt_start(&data->wdt_dev);
+
+ return 0;
+}
+
+static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev)
+{
+ struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
+
+ if (watchdog_active(&data->wdt_dev))
+ meson_gxbb_wdt_stop(&data->wdt_dev);
+
+ return 0;
+}
+
+static const struct dev_pm_ops meson_gxbb_wdt_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(meson_gxbb_wdt_suspend, meson_gxbb_wdt_resume)
+};
+
+static const struct of_device_id meson_gxbb_wdt_dt_ids[] = {
+ { .compatible = "amlogic,meson-gxbb-wdt", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, meson_gxbb_wdt_dt_ids);
+
+static int meson_gxbb_wdt_probe(struct platform_device *pdev)
+{
+ struct meson_gxbb_wdt *data;
+ struct resource *res;
+ int ret;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ data->reg_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(data->reg_base))
+ return PTR_ERR(data->reg_base);
+
+ data->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(data->clk))
+ return PTR_ERR(data->clk);
+
+ clk_prepare_enable(data->clk);
+
+ platform_set_drvdata(pdev, data);
+
+ data->wdt_dev.parent = &pdev->dev;
+ data->wdt_dev.info = &meson_gxbb_wdt_info;
+ data->wdt_dev.ops = &meson_gxbb_wdt_ops;
+ data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK;
+ data->wdt_dev.min_hw_heartbeat_ms = 1;
+ data->wdt_dev.timeout = DEFAULT_TIMEOUT;
+ watchdog_set_drvdata(&data->wdt_dev, data);
+
+ watchdog_init_timeout(&data->wdt_dev, DEFAULT_TIMEOUT, &pdev->dev);
+
+ ret = watchdog_register_device(&data->wdt_dev);
+ if (ret)
+ return ret;
+
+ /* Setup with 1ms timebase */
+ writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) |
+ GXBB_WDT_CTRL_EE_RESET |
+ GXBB_WDT_CTRL_CLK_EN |
+ GXBB_WDT_CTRL_CLKDIV_EN,
+ data->reg_base + GXBB_WDT_CTRL_REG);
+ meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
+ meson_gxbb_wdt_ping(&data->wdt_dev);
+
+ return 0;
+}
+
+static int meson_gxbb_wdt_remove(struct platform_device *pdev)
+{
+ struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
+
+ watchdog_unregister_device(&data->wdt_dev);
+
+ return 0;
+}
+
+static void meson_gxbb_wdt_shutdown(struct platform_device *pdev)
+{
+ struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
+
+ meson_gxbb_wdt_stop(&data->wdt_dev);
+}
+
+static struct platform_driver meson_gxbb_wdt_driver = {
+ .probe = meson_gxbb_wdt_probe,
+ .remove = meson_gxbb_wdt_remove,
+ .shutdown = meson_gxbb_wdt_shutdown,
+ .driver = {
+ .name = "meson-gxbb-wdt",
+ .pm = &meson_gxbb_wdt_pm_ops,
+ .of_match_table = meson_gxbb_wdt_dt_ids,
+ },
+};
+
+module_platform_driver(meson_gxbb_wdt_driver);
+
+MODULE_ALIAS("platform:meson-gxbb-wdt");
+MODULE_AUTHOR("Neil Armstrong <[hidden email]>");
+MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver");
+MODULE_LICENSE("Dual BSD/GPL");
--
2.7.0

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

[RFC PATCH 2/3] dt-bindings: watchdog: Add Meson GXBB Watchdog bindings

Neil Armstrong-3
In reply to this post by Neil Armstrong-3
Signed-off-by: Neil Armstrong <[hidden email]>
---
 .../devicetree/bindings/watchdog/meson-gxbb-wdt.txt         | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/watchdog/meson-gxbb-wdt.txt

diff --git a/Documentation/devicetree/bindings/watchdog/meson-gxbb-wdt.txt b/Documentation/devicetree/bindings/watchdog/meson-gxbb-wdt.txt
new file mode 100644
index 0000000..d06c0a0
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/meson-gxbb-wdt.txt
@@ -0,0 +1,13 @@
+Meson GXBB SoCs Watchdog timer
+
+Required properties:
+
+- compatible : should be "amlogic,meson-gxbb-wdt"
+- reg : Specifies base physical address and size of the registers.
+
+Example:
+
+wdt: watchdog@98d0 {
+ compatible = "amlogic,meson-gxbb-wdt";
+ reg = <0 0x98d0 0x0 0x10>;
+};
--
2.7.0

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

[RFC PATCH 3/3] ARM64: dts: amlogic: meson-gxbb: Add watchdog node

Neil Armstrong-3
In reply to this post by Neil Armstrong-3
Signed-off-by: Neil Armstrong <[hidden email]>
---
 arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
index 832815d..bcca82f 100644
--- a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
@@ -136,6 +136,12 @@
  clocks = <&xtal>;
  status = "disabled";
  };
+
+ watchdog@98d0 {
+ compatible = "amlogic,meson-gxbb-wdt";
+ reg = <0x0 0x098d0 0x0 0x10>;
+ clocks = <&xtal>;
+ };
  };
 
  gic: interrupt-controller@c4301000 {
--
2.7.0

Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: [RFC PATCH 1/3] watchdog: Add Meson GXBB Watchdog Driver

Carlo Caione
In reply to this post by Neil Armstrong-3
On 26/05/16 09:51, Neil Armstrong wrote:
> Add watchdog specific driver for Amlogic Meson GXBB SoC.
>
> Signed-off-by: Neil Armstrong <[hidden email]>
> +

[...]

> +#define DEFAULT_TIMEOUT 10 /* seconds */
> +
> +#define GXBB_WDT_CTRL_REG 0x0
> +#define GXBB_WDT_CTRL1_REG 0x4
> +#define GXBB_WDT_TCNT_REG 0x8
> +#define GXBB_WDT_RSET_REG 0xc
> +
> +#define GXBB_WDT_CTRL_EE_RESET_NOW BIT(26)
> +
> +#define GXBB_WDT_CTRL_CLKDIV_EN BIT(25)
> +#define GXBB_WDT_CTRL_CLK_EN BIT(24)
> +#define GXBB_WDT_CTRL_IRQ_EN BIT(23)
> +#define GXBB_WDT_CTRL_EE_RESET BIT(21)
> +#define GXBB_WDT_CTRL_XTAL_SEL (0)
> +#define GXBB_WDT_CTRL_CLK81_SEL BIT(19)
> +#define GXBB_WDT_CTRL_EN BIT(18)
> +#define GXBB_WDT_CTRL_DIV_MASK (BIT(18)-1)
> +
> +#define GXBB_WDT_CTRL1_GPIO_PULSE BIT(17)
> +#define GXBB_WDT_CTRL1_GPIO_POL_RESET_0 BIT(16)
> +#define GXBB_WDT_CTRL1_GPIO_POL_RESET_1 (0)
> +#define GXBB_WDT_CTRL1_GPIO_PULSE_CNT (BIT(16)-1)
> +
> +#define GXBB_WDT_TCNT_SETUP_MASK (BIT(16)-1)
> +#define GXBB_WDT_TCNT_CNT_SHIFT 16

Indentation

[...]

> +int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev,
> +       unsigned int timeout)
> +{
> + struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
> +
> + if (watchdog_active(wdt_dev))
> + meson_gxbb_wdt_stop(wdt_dev);
> +
> + meson_gxbb_wdt_ping(wdt_dev);
> +
> + writel(timeout*1000, data->reg_base + GXBB_WDT_TCNT_REG);

nit: spaces around "*"

[...]
> + data->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(data->clk))
> + return PTR_ERR(data->clk);
> +
> + clk_prepare_enable(data->clk);

Do we need to merge the clock controller driver before this?

Cheers,

--
Carlo Caione
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: [RFC PATCH 2/3] dt-bindings: watchdog: Add Meson GXBB Watchdog bindings

Carlo Caione
In reply to this post by Neil Armstrong-3
On 26/05/16 09:51, Neil Armstrong wrote:

> Signed-off-by: Neil Armstrong <[hidden email]>
> ---
>  .../devicetree/bindings/watchdog/meson-gxbb-wdt.txt         | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/watchdog/meson-gxbb-wdt.txt
>
> diff --git a/Documentation/devicetree/bindings/watchdog/meson-gxbb-wdt.txt b/Documentation/devicetree/bindings/watchdog/meson-gxbb-wdt.txt
> new file mode 100644
> index 0000000..d06c0a0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/watchdog/meson-gxbb-wdt.txt
> @@ -0,0 +1,13 @@
> +Meson GXBB SoCs Watchdog timer
> +
> +Required properties:
> +
> +- compatible : should be "amlogic,meson-gxbb-wdt"
> +- reg : Specifies base physical address and size of the registers.

'clocks' is also required IIRC.

Thanks,

--
Carlo Caione
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: [RFC PATCH 1/3] watchdog: Add Meson GXBB Watchdog Driver

Guenter Roeck-5
In reply to this post by Neil Armstrong-3
On 05/26/2016 12:51 AM, Neil Armstrong wrote:
> Add watchdog specific driver for Amlogic Meson GXBB SoC.
>

Wondering - why RFC ?

> Signed-off-by: Neil Armstrong <[hidden email]>
> ---
>   drivers/watchdog/Makefile         |   1 +
>   drivers/watchdog/meson_gxbb_wdt.c | 287 ++++++++++++++++++++++++++++++++++++++
>   2 files changed, 288 insertions(+)
>   create mode 100644 drivers/watchdog/meson_gxbb_wdt.c
>
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 9bde095..7679d93 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -68,6 +68,7 @@ obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o
>   obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o
>   obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o
>   obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o
> +obj-$(CONFIG_MESON_WATCHDOG) += meson_gxbb_wdt.o
>   obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o
>   obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o
>   obj-$(CONFIG_LPC18XX_WATCHDOG) += lpc18xx_wdt.o
> diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
> new file mode 100644
> index 0000000..0c7c0d9
> --- /dev/null
> +++ b/drivers/watchdog/meson_gxbb_wdt.c
> @@ -0,0 +1,287 @@
> +/*
> + * This file is provided under a dual BSD/GPLv2 license.  When using or
> + * redistributing this file, you may do so under either license.
> + *
> + * GPL LICENSE SUMMARY
> + *
> + * Copyright (c) 2016 BayLibre, SAS.
> + * Author: Neil Armstrong <[hidden email]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of version 2 of the GNU General Public License as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, see <http://www.gnu.org/licenses/>.
> + * The full GNU General Public License is included in this distribution
> + * in the file called COPYING.
> + *
> + * BSD LICENSE
> + *
> + * Copyright (c) 2016 BayLibre, SAS.
> + * Author: Neil Armstrong <[hidden email]>
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + *
> + *   * Redistributions of source code must retain the above copyright
> + *     notice, this list of conditions and the following disclaimer.
> + *   * Redistributions in binary form must reproduce the above copyright
> + *     notice, this list of conditions and the following disclaimer in
> + *     the documentation and/or other materials provided with the
> + *     distribution.
> + *   * Neither the name of Intel Corporation nor the names of its
> + *     contributors may be used to endorse or promote products derived
> + *     from this software without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
> + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
> + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
> + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
> + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
> + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
> + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
> + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
> + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
> + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
> + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> + */
> +#include <linux/err.h>
> +#include <linux/module.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/clk.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +#include <linux/watchdog.h>
> +
> +#define DEFAULT_TIMEOUT 10 /* seconds */
> +
> +#define GXBB_WDT_CTRL_REG 0x0
> +#define GXBB_WDT_CTRL1_REG 0x4
> +#define GXBB_WDT_TCNT_REG 0x8
> +#define GXBB_WDT_RSET_REG 0xc
> +
> +#define GXBB_WDT_CTRL_EE_RESET_NOW BIT(26)
> +
> +#define GXBB_WDT_CTRL_CLKDIV_EN BIT(25)
> +#define GXBB_WDT_CTRL_CLK_EN BIT(24)
> +#define GXBB_WDT_CTRL_IRQ_EN BIT(23)
> +#define GXBB_WDT_CTRL_EE_RESET BIT(21)
> +#define GXBB_WDT_CTRL_XTAL_SEL (0)
> +#define GXBB_WDT_CTRL_CLK81_SEL BIT(19)
> +#define GXBB_WDT_CTRL_EN BIT(18)
> +#define GXBB_WDT_CTRL_DIV_MASK (BIT(18)-1)
> +
> +#define GXBB_WDT_CTRL1_GPIO_PULSE BIT(17)
> +#define GXBB_WDT_CTRL1_GPIO_POL_RESET_0 BIT(16)
> +#define GXBB_WDT_CTRL1_GPIO_POL_RESET_1 (0)
> +#define GXBB_WDT_CTRL1_GPIO_PULSE_CNT (BIT(16)-1)
> +

Spaces around operators, please.

> +#define GXBB_WDT_TCNT_SETUP_MASK (BIT(16)-1)
> +#define GXBB_WDT_TCNT_CNT_SHIFT 16
> +
> +struct meson_gxbb_wdt {
> + void __iomem *reg_base;
> + struct watchdog_device wdt_dev;
> + struct clk *clk;
> +};
> +
> +int meson_gxbb_wdt_start(struct watchdog_device *wdt_dev)

Functions should all be static.

> +{
> + struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
> +
> + writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN,
> + data->reg_base + GXBB_WDT_CTRL_REG);
> +
> + return 0;
> +}
> +
> +int meson_gxbb_wdt_stop(struct watchdog_device *wdt_dev)
> +{
> + struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
> +
> + writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN,
> + data->reg_base + GXBB_WDT_CTRL_REG);
> +
> + return 0;
> +}
> +
> +unsigned int meson_gxbb_wdt_status(struct watchdog_device *wdt_dev)
> +{
> + struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
> +
> + return !!(readl(data->reg_base + GXBB_WDT_CTRL_REG) & GXBB_WDT_CTRL_EN);

This function is not supposed to return 0/1 but a bit mask with relevant
WDIOF_bits set. sbsa_gwdt.c is buggy (oops, and I reviewed it ;-), so
please don't use it as example; it doesn't make much sense to return
a kernel-only flag to user space.

Overall I would suggest to not implement the function at all. We'll have
to revisit it - its current implementation in the watchdog core does not
make much sense and for the most part only returns 0 to user space.
The only driver implementing it (sbsa) returns a bad value. It is also
_not_ supposed to return the "watchdog running" status as currently
implemented (there is no WDIOF_ flag indicating that the watchdog is
running).

> +}
> +
> +int meson_gxbb_wdt_ping(struct watchdog_device *wdt_dev)
> +{
> + struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
> +
> + writel(0, data->reg_base + GXBB_WDT_RSET_REG);
> +
> + return 0;
> +}
> +
> +int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev,
> +       unsigned int timeout)
> +{
> + struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
> +
> + if (watchdog_active(wdt_dev))
> + meson_gxbb_wdt_stop(wdt_dev);
> +

Is the stop/start sequence mandatory ? It leaves the system unprotected
for a few cycles, so it is undesirable.

> + meson_gxbb_wdt_ping(wdt_dev);
> +
> + writel(timeout*1000, data->reg_base + GXBB_WDT_TCNT_REG);
> +
> + if (watchdog_active(wdt_dev))
> + meson_gxbb_wdt_start(wdt_dev);
> +
> + return 0;
> +}
> +
> +unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev)
> +{
> + struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
> + unsigned long reg;
> +
> + reg = readl(data->reg_base + GXBB_WDT_TCNT_REG);
> +
> + return ((reg >> GXBB_WDT_TCNT_CNT_SHIFT)-
> + (reg & GXBB_WDT_TCNT_SETUP_MASK)) / 1000;
> +}
> +
> +static const struct watchdog_ops meson_gxbb_wdt_ops = {
> + .start = meson_gxbb_wdt_start,
> + .stop = meson_gxbb_wdt_stop,
> + .status = meson_gxbb_wdt_status,
> + .ping = meson_gxbb_wdt_ping,
> + .set_timeout = meson_gxbb_wdt_set_timeout,
> + .get_timeleft = meson_gxbb_wdt_get_timeleft,
> +};
> +
> +static const struct watchdog_info meson_gxbb_wdt_info = {
> + .identity = "meson-gxbb-wdt",
> + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
> +};
> +
> +static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev)
> +{
> + struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
> +
> + if (watchdog_active(&data->wdt_dev))
> + meson_gxbb_wdt_start(&data->wdt_dev);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev)
> +{
> + struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
> +
> + if (watchdog_active(&data->wdt_dev))
> + meson_gxbb_wdt_stop(&data->wdt_dev);
> +
> + return 0;
> +}
> +
> +static const struct dev_pm_ops meson_gxbb_wdt_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(meson_gxbb_wdt_suspend, meson_gxbb_wdt_resume)
> +};
> +
> +static const struct of_device_id meson_gxbb_wdt_dt_ids[] = {
> + { .compatible = "amlogic,meson-gxbb-wdt", },
> + { /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, meson_gxbb_wdt_dt_ids);
> +
> +static int meson_gxbb_wdt_probe(struct platform_device *pdev)
> +{
> + struct meson_gxbb_wdt *data;
> + struct resource *res;
> + int ret;
> +
> + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + data->reg_base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(data->reg_base))
> + return PTR_ERR(data->reg_base);
> +
> + data->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(data->clk))
> + return PTR_ERR(data->clk);
> +
> + clk_prepare_enable(data->clk);
> +
> + platform_set_drvdata(pdev, data);
> +
> + data->wdt_dev.parent = &pdev->dev;
> + data->wdt_dev.info = &meson_gxbb_wdt_info;
> + data->wdt_dev.ops = &meson_gxbb_wdt_ops;
> + data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK;
> + data->wdt_dev.min_hw_heartbeat_ms = 1;

Does the device require a minimum time between heartbeats ?
Just asking, because you violate it yourself below.

If you want to set the minimum timeout, that would be min_timeout.

> + data->wdt_dev.timeout = DEFAULT_TIMEOUT;
> + watchdog_set_drvdata(&data->wdt_dev, data);
> +
> + watchdog_init_timeout(&data->wdt_dev, DEFAULT_TIMEOUT, &pdev->dev);
> +

DEFAULT_TIMEOUT is unnecessary here. Since the default timeout is already set,
it makes the call useless.

> + ret = watchdog_register_device(&data->wdt_dev);
> + if (ret)
> + return ret;
> +
> + /* Setup with 1ms timebase */
> + writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) |
> + GXBB_WDT_CTRL_EE_RESET |
> + GXBB_WDT_CTRL_CLK_EN |
> + GXBB_WDT_CTRL_CLKDIV_EN,
> + data->reg_base + GXBB_WDT_CTRL_REG);
> + meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);

set_timeout already calls the ping function. Also, the functions should be called
prior to watchdog registration to avoid race conditions.

> + meson_gxbb_wdt_ping(&data->wdt_dev);

This is unusual. If the watchdog can be already running, it might make sense
to tell the core about it (set WDOG_HW_RUNNING in the status field), so it
can send heartbeats until user space opens the device.

> +
> + return 0;
> +}
> +
> +static int meson_gxbb_wdt_remove(struct platform_device *pdev)
> +{
> + struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
> +
> + watchdog_unregister_device(&data->wdt_dev);
> +
> + return 0;
> +}
> +
> +static void meson_gxbb_wdt_shutdown(struct platform_device *pdev)
> +{
> + struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
> +
> + meson_gxbb_wdt_stop(&data->wdt_dev);
> +}
> +
> +static struct platform_driver meson_gxbb_wdt_driver = {
> + .probe = meson_gxbb_wdt_probe,
> + .remove = meson_gxbb_wdt_remove,
> + .shutdown = meson_gxbb_wdt_shutdown,
> + .driver = {
> + .name = "meson-gxbb-wdt",
> + .pm = &meson_gxbb_wdt_pm_ops,
> + .of_match_table = meson_gxbb_wdt_dt_ids,
> + },
> +};
> +
> +module_platform_driver(meson_gxbb_wdt_driver);
> +
> +MODULE_ALIAS("platform:meson-gxbb-wdt");
> +MODULE_AUTHOR("Neil Armstrong <[hidden email]>");
> +MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver");
> +MODULE_LICENSE("Dual BSD/GPL");
>

Loading...