Re: [PATCH v2 3/8] watchdog: at91rm9200: use the regmap from mfd

From: Guenter Roeck
Date: Fri Jan 09 2015 - 19:39:55 EST


On 01/09/2015 01:51 AM, Alexandre Belloni wrote:
The system timer MFD driver is providing a regmap. Use it to access the
registers.

Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
---
drivers/watchdog/Kconfig | 2 +-
drivers/watchdog/at91rm9200_wdt.c | 27 +++++++++------------------
2 files changed, 10 insertions(+), 19 deletions(-)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 08f41add1461..18c73bc159fc 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -154,7 +154,7 @@ config ARM_SP805_WATCHDOG

config AT91RM9200_WATCHDOG
tristate "AT91RM9200 watchdog"
- depends on SOC_AT91RM9200
+ depends on SOC_AT91RM9200 && MFD_ATMEL_ST
help
Watchdog timer embedded into AT91RM9200 chips. This will reboot your
system when the timeout is reached.
diff --git a/drivers/watchdog/at91rm9200_wdt.c b/drivers/watchdog/at91rm9200_wdt.c
index d244112d5b6f..a493fe4b0dfc 100644
--- a/drivers/watchdog/at91rm9200_wdt.c
+++ b/drivers/watchdog/at91rm9200_wdt.c
@@ -14,25 +14,22 @@
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/fs.h>
-#include <linux/init.h>
-#include <linux/io.h>
#include <linux/kernel.h>
+#include <linux/mfd/atmel-st.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
-#include <linux/types.h>
+#include <linux/regmap.h>
#include <linux/watchdog.h>
#include <linux/uaccess.h>
-#include <linux/of.h>
-#include <linux/of_device.h>
-#include <mach/at91_st.h>

#define WDT_DEFAULT_TIME 5 /* seconds */
#define WDT_MAX_TIME 256 /* seconds */

static int wdt_time = WDT_DEFAULT_TIME;
static bool nowayout = WATCHDOG_NOWAYOUT;
+static struct regmap *regmap_st;

module_param(wdt_time, int, 0);
MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="
@@ -55,7 +52,7 @@ static unsigned long at91wdt_busy;
*/
static inline void at91_wdt_stop(void)
{
- at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN);
+ regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN);
}

/*
@@ -63,9 +60,9 @@ static inline void at91_wdt_stop(void)
*/
static inline void at91_wdt_start(void)
{
- at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN |
+ regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN |
(((65536 * wdt_time) >> 8) & AT91_ST_WDV));
- at91_st_write(AT91_ST_CR, AT91_ST_WDRST);
+ regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
}

/*
@@ -73,7 +70,7 @@ static inline void at91_wdt_start(void)
*/
static inline void at91_wdt_reload(void)
{
- at91_st_write(AT91_ST_CR, AT91_ST_WDRST);
+ regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
}

/* ......................................................................... */
@@ -204,6 +201,7 @@ static struct miscdevice at91wdt_miscdev = {
static int at91wdt_probe(struct platform_device *pdev)
{
int res;
+ regmap_st = dev_get_drvdata(pdev->dev.parent);


Is it guaranteed that parent is never NULL, and that the parent's
drvdata is always set ?

Also, it seems that regmap_st will be overwritten if the device
is already open (see code below). That may not be a good idea.

Guenter

if (at91wdt_miscdev.parent)
return -EBUSY;
@@ -254,12 +252,6 @@ static int at91wdt_resume(struct platform_device *pdev)
#define at91wdt_resume NULL
#endif

-static const struct of_device_id at91_wdt_dt_ids[] = {
- { .compatible = "atmel,at91rm9200-wdt" },
- { /* sentinel */ }
-};
-MODULE_DEVICE_TABLE(of, at91_wdt_dt_ids);
-
static struct platform_driver at91wdt_driver = {
.probe = at91wdt_probe,
.remove = at91wdt_remove,
@@ -267,8 +259,7 @@ static struct platform_driver at91wdt_driver = {
.suspend = at91wdt_suspend,
.resume = at91wdt_resume,
.driver = {
- .name = "at91_wdt",
- .of_match_table = at91_wdt_dt_ids,
+ .name = "atmel_st_watchdog",
},
};



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