Re: [PATCH v2 1/3] watchdog: Add Meson GXBB Watchdog Driver
From: Guenter Roeck
Date: Sat Jun 04 2016 - 13:58:30 EST
On 06/03/2016 01:36 AM, Neil Armstrong wrote:
Add watchdog specific driver for Amlogic Meson GXBB SoC.
Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
drivers/watchdog/Kconfig | 10 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/meson_gxbb_wdt.c | 268 ++++++++++++++++++++++++++++++++++++++
3 files changed, 279 insertions(+)
create mode 100644 drivers/watchdog/meson_gxbb_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 9c41431..ad38cf5 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -609,6 +609,16 @@ config QCOM_WDT
To compile this driver as a module, choose M here: the
module will be called qcom_wdt.
+config MESON_GXBB_WATCHDOG
+ tristate "Amlogic Meson GXBB SoCs watchdog support"
+ depends on ARCH_MESON
+ select WATCHDOG_CORE
+ help
+ Say Y here to include support for the watchdog timer
+ in Amlogic Meson GXBB SoCs.
+ To compile this driver as a module, choose M here: the
+ module will be called meson_gxbb_wdt.
+
config MESON_WATCHDOG
tristate "Amlogic Meson SoCs watchdog support"
depends on ARCH_MESON
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 9bde095..a46bf09 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -67,6 +67,7 @@ obj-$(CONFIG_ST_LPC_WATCHDOG) += st_lpc_wdt.o
obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o
obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o
obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o
+obj-$(CONFIG_MESON_GXBB_WATCHDOG) += meson_gxbb_wdt.o
obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o
obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o
obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o
diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
new file mode 100644
index 0000000..ab3d789
--- /dev/null
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -0,0 +1,268 @@
+/*
+ * 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 <narmstrong@xxxxxxxxxxxx>
+ *
+ * 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 <narmstrong@xxxxxxxxxxxx>
+ *
Nitpick, but you don't really need the copyright and author lines twice.
+ * 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/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+
+#define DEFAULT_TIMEOUT 30 /* seconds */
+
+#define GXBB_WDT_CTRL_REG 0x0
+#define GXBB_WDT_TCNT_REG 0x8
+#define GXBB_WDT_RSET_REG 0xc
+
+#define GXBB_WDT_CTRL_CLKDIV_EN BIT(25)
+#define GXBB_WDT_CTRL_CLK_EN BIT(24)
+#define GXBB_WDT_CTRL_EE_RESET BIT(21)
+#define GXBB_WDT_CTRL_EN BIT(18)
+#define GXBB_WDT_CTRL_DIV_MASK (BIT(18) - 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;
+};
+
+static 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;
+}
+
+static 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;
+}
+
+static 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;
+}
+
+static int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev,
+ unsigned int timeout)
+{
+ struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
+ unsigned long tcnt = timeout * 1000;
+
+ if (tcnt > GXBB_WDT_TCNT_SETUP_MASK)
+ return -EINVAL;
+
No; what you need to do is
if (tcnt > GXBB_WDT_TCNT_SETUP_MASK)
tcnt = GXBB_WDT_TCNT_SETUP_MASK;
Also, you need
wdt_dev->timeout = timeout;
+ meson_gxbb_wdt_ping(wdt_dev);
+
+ writel(tcnt, data->reg_base + GXBB_WDT_TCNT_REG);
+
+ return 0;
+}
+
+static 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,
+ .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 Watchdog",
+ .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_timeout = 1;
+ data->wdt_dev.timeout = DEFAULT_TIMEOUT;
+ watchdog_set_drvdata(&data->wdt_dev, data);
+
+ /* 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);
+
+ ret = watchdog_register_device(&data->wdt_dev);
+ if (ret) {
+ clk_disable_unprepare(data->clk);
+ return ret;
+ }
+
+ 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);
+
+ clk_disable_unprepare(data->clk);
+
+ 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 <narmstrong@xxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver");
+MODULE_LICENSE("Dual BSD/GPL");