[RESEND PATCH 2/3] watchdog: max63xx: add GPIO support
From: Vivien Didelot
Date: Mon Jun 15 2015 - 15:59:54 EST
This patch adds support for GPIO wired MAX63xx devices. It adds a
platform data structure which can be filled by a platform code with the
GPIO line numbers. The driver takes care of requesting and releasing
them.
Signed-off-by: Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx>
---
drivers/watchdog/Kconfig | 2 +-
drivers/watchdog/max63xx_wdt.c | 108 ++++++++++++++++++++++++++----
include/linux/platform_data/max63xx_wdt.h | 27 ++++++++
3 files changed, 123 insertions(+), 14 deletions(-)
create mode 100644 include/linux/platform_data/max63xx_wdt.h
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index c0e3a2e..b81d916 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -418,7 +418,7 @@ config TS72XX_WATCHDOG
config MAX63XX_WATCHDOG
tristate "Maxim MAX6369 Pin-Selectable Watchdog Timer and compatibles"
- depends on HAS_IOMEM
+ depends on HAS_IOMEM || GPIOLIB
select WATCHDOG_CORE
help
Support for MAX6369, MAX6370, MAX6371, MAX6372, MAX6373, and MAX6374.
diff --git a/drivers/watchdog/max63xx_wdt.c b/drivers/watchdog/max63xx_wdt.c
index 01fb4ef..9ab9fd1 100644
--- a/drivers/watchdog/max63xx_wdt.c
+++ b/drivers/watchdog/max63xx_wdt.c
@@ -3,13 +3,12 @@
*
* Copyright (C) 2009 Marc Zyngier <maz@xxxxxxxxxxxxxxx>
*
+ * Copyright (C) 2015 Savoir-faire Linux Inc.
+ * Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx>
+ *
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
- *
- * This driver assumes the watchdog pins are memory mapped (as it is
- * the case for the Arcom Zeus). Should it be connected over GPIOs or
- * another interface, some abstraction will have to be introduced.
*/
#include <linux/err.h>
@@ -20,6 +19,8 @@
#include <linux/watchdog.h>
#include <linux/bitops.h>
#include <linux/platform_device.h>
+#include <linux/platform_data/max63xx_wdt.h>
+#include <linux/gpio.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/slab.h>
@@ -47,6 +48,9 @@ MODULE_PARM_DESC(nodelay, "Force selection of a timeout setting without initial
struct max63xx_data {
const struct max63xx_timeout *timeout;
+ /* Platform data for optional config, such as GPIOs */
+ struct max63xx_platform_data *pdata;
+
/* For memory mapped pins */
void __iomem *base;
spinlock_t lock;
@@ -168,6 +172,50 @@ static const struct watchdog_ops max63xx_mmap_ops = {
.ping = max63xx_mmap_ping,
};
+static int max63xx_gpio_ping(struct watchdog_device *wdev)
+{
+ struct max63xx_data *data = watchdog_get_drvdata(wdev);
+
+ gpio_set_value_cansleep(data->pdata->wdi, 1);
+ gpio_set_value_cansleep(data->pdata->wdi, 0);
+
+ return 0;
+}
+
+static inline void max63xx_gpio_set(struct watchdog_device *wdev, u8 set)
+{
+ struct max63xx_data *data = watchdog_get_drvdata(wdev);
+
+ gpio_set_value_cansleep(data->pdata->set0, set & BIT(0));
+ gpio_set_value_cansleep(data->pdata->set1, set & BIT(1));
+ gpio_set_value_cansleep(data->pdata->set2, set & BIT(2));
+}
+
+static int max63xx_gpio_start(struct watchdog_device *wdev)
+{
+ struct max63xx_data *data = watchdog_get_drvdata(wdev);
+
+ max63xx_gpio_set(wdev, data->timeout->wdset);
+
+ /* Check for an edge triggered startup */
+ if (data->timeout->tdelay == 0)
+ max63xx_gpio_ping(wdev);
+ return 0;
+}
+
+static int max63xx_gpio_stop(struct watchdog_device *wdev)
+{
+ max63xx_gpio_set(wdev, MAX63XX_DISABLED);
+ return 0;
+}
+
+static const struct watchdog_ops max63xx_gpio_ops = {
+ .owner = THIS_MODULE,
+ .start = max63xx_gpio_start,
+ .stop = max63xx_gpio_stop,
+ .ping = max63xx_gpio_ping,
+};
+
static const struct watchdog_info max63xx_wdt_info = {
.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "MAX63xx Watchdog Timer",
@@ -175,7 +223,6 @@ static const struct watchdog_info max63xx_wdt_info = {
static int max63xx_wdt_probe(struct platform_device *pdev)
{
- struct resource *mem;
struct watchdog_device *wdev;
struct max63xx_data *data;
struct max63xx_timeout *table;
@@ -190,6 +237,8 @@ static int max63xx_wdt_probe(struct platform_device *pdev)
table = (struct max63xx_timeout *) pdev->id_entry->driver_data;
+ data->pdata = dev_get_platdata(&pdev->dev);
+
if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
heartbeat = DEFAULT_HEARTBEAT;
@@ -206,14 +255,47 @@ static int max63xx_wdt_probe(struct platform_device *pdev)
wdev->timeout = data->timeout->twd;
wdev->info = &max63xx_wdt_info;
- mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- data->base = devm_ioremap_resource(&pdev->dev, mem);
- if (IS_ERR(data->base))
- return PTR_ERR(data->base);
-
- spin_lock_init(&data->lock);
-
- wdev->ops = &max63xx_mmap_ops;
+ /* GPIO or memory mapped? */
+ if (data->pdata && data->pdata->wdi) {
+ int err;
+
+ err = devm_gpio_request_one(&pdev->dev, data->pdata->wdi,
+ GPIOF_OUT_INIT_LOW,
+ "MAX63XX Watchdog WDI");
+ if (err)
+ return err;
+
+ err = devm_gpio_request_one(&pdev->dev, data->pdata->set0,
+ GPIOF_OUT_INIT_LOW,
+ "MAX63XX Watchdog SET0");
+ if (err)
+ return err;
+
+ err = devm_gpio_request_one(&pdev->dev, data->pdata->set1,
+ GPIOF_OUT_INIT_LOW,
+ "MAX63XX Watchdog SET1");
+ if (err)
+ return err;
+
+ err = devm_gpio_request_one(&pdev->dev, data->pdata->set2,
+ GPIOF_OUT_INIT_LOW,
+ "MAX63XX Watchdog SET2");
+ if (err)
+ return err;
+
+ wdev->ops = &max63xx_gpio_ops;
+ } else {
+ struct resource *mem;
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ data->base = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(data->base))
+ return PTR_ERR(data->base);
+
+ spin_lock_init(&data->lock);
+
+ wdev->ops = &max63xx_mmap_ops;
+ }
watchdog_set_drvdata(wdev, data);
platform_set_drvdata(pdev, wdev);
diff --git a/include/linux/platform_data/max63xx_wdt.h b/include/linux/platform_data/max63xx_wdt.h
new file mode 100644
index 0000000..ae28024
--- /dev/null
+++ b/include/linux/platform_data/max63xx_wdt.h
@@ -0,0 +1,27 @@
+/*
+ * Maxim MAX6369 Pin-Selectable Watchdog Timer and compatibles
+ *
+ * Copyright (c) 2015 Savoir-faire Linux Inc.
+ * Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _PDATA_MAX63XX_H
+#define _PDATA_MAX63XX_H
+
+/**
+ * struct max63xx_platform_data - MAX63xx connectivity info
+ * @wdi: Watchdog Input GPIO number.
+ * @set0: Watchdog SET0 GPIO number.
+ * @set1: Watchdog SET1 GPIO number.
+ * @set2: Watchdog SET2 GPIO number.
+ */
+struct max63xx_platform_data {
+ unsigned int wdi;
+ unsigned int set0, set1, set2;
+};
+
+#endif /* _PDATA_MAX63XX_H */
--
2.4.2
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