watchdog: at91rm9200: use the system timer syscon

Use a syscon regmap to access the system timer registers.

Also, rename the driver atmel_st_watchdog to stop conflicting with
at91sam9_wdt.c

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

2 files changed, 23 insertions, 8 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 16f202350997..ce4f3a7f95fd 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_SYSCON
         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..e6fa87d85de3 100644
--- a/drivers/watchdog/at91rm9200_wdt.c
+++ b/drivers/watchdog/at91rm9200_wdt.c
@@ -17,22 +17,25 @@
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/atmel-st.h>
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/types.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 +58,7 @@ 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 +66,9 @@ 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 +76,7 @@ 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);
 }
 
 /* ......................................................................... */
@@ -203,12 +206,24 @@ static struct miscdevice at91wdt_miscdev = {
 
 static int at91wdt_probe(struct platform_device *pdev)
 {
+        struct device *dev = &pdev->dev;
+        struct device *parent;
         int res;
 
         if (at91wdt_miscdev.parent)
                 return -EBUSY;
         at91wdt_miscdev.parent = &pdev->dev;
 
+        parent = dev->parent;
+        if (!parent) {
+                dev_err(dev, "no parent\n");
+                return -ENODEV;
+        }
+
+        regmap_st = syscon_node_to_regmap(parent->of_node);
+        if (!regmap_st)
+                return -ENODEV;
+
         res = misc_register(&at91wdt_miscdev);
         if (res)
                 return res;
@@ -267,7 +282,7 @@ static struct platform_driver at91wdt_driver = {
         .suspend        = at91wdt_suspend,
         .resume         = at91wdt_resume,
         .driver         = {
-                .name   = "at91_wdt",
+                .name   = "atmel_st_watchdog",
                 .of_match_table = at91_wdt_dt_ids,
         },
 };
@@ -296,4 +311,4 @@ module_exit(at91_wdt_exit);
 MODULE_AUTHOR("Andrew Victor");
 MODULE_DESCRIPTION("Watchdog driver for Atmel AT91RM9200");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:at91_wdt");
+MODULE_ALIAS("platform:atmel_st_watchdog");