[U-Boot] [PATCH 08/15] RX-51: Add support for resetting twl4030 watchdog

["Pali Rohár" <pali.rohar@gmail.com>]

 * use test_and_set_bit and __clear_bit to access twl4030 i2c bus only once at same time
 * do not reset watchdog too often (max every 2 seconds)
---
 board/nokia/rx51/rx51.c      |   25 +++++++++++++++++++++++--
 include/configs/nokia_rx51.h |    1 +
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/board/nokia/rx51/rx51.c b/board/nokia/rx51/rx51.c
index 96e65d6..a90e4dd 100644
--- a/board/nokia/rx51/rx51.c
+++ b/board/nokia/rx51/rx51.c
@@ -36,6 +36,7 @@
 #include <i2c.h>
 #include <video_fb.h>
 #include <asm/io.h>
+#include <asm/bitops.h>
 #include <asm/arch/mux.h>
 #include <asm/arch/sys_proto.h>
 #include <asm/omap_gpio.h>
@@ -192,6 +193,23 @@ int rx51_kp_init(void)
 	return ret;
 }
 
+static unsigned long int twl_wd_start = 0;
+static volatile unsigned long int twl_chip_lock;
+
+void hw_watchdog_reset(void)
+{
+
+	if ( get_timer(twl_wd_start) < 2 * CONFIG_SYS_HZ )
+		return;
+
+	if ( test_and_set_bit(0, &twl_chip_lock) )
+		return;
+	twl4030_i2c_write_u8(TWL4030_CHIP_PM_RECEIVER, 31, TWL4030_PM_RECEIVER_WATCHDOG_CFG);
+	__clear_bit(0, &twl_chip_lock);
+
+	twl_wd_start = get_timer(0);
+}
+
 char rx51_kp_fill(u8 k, u8 mods)
 {
 	if (mods & 2) { /* fn */
@@ -217,6 +235,9 @@ int rx51_kp_tstc(void)
 	u8 intr;
 	u8 mods;
 
+	if ( test_and_set_bit(0, &twl_chip_lock) )
+		return 0;
+
 	/* twl4030 remembers up to 2 events */
 	for (i = 0; i < 2; i++)	{
 
@@ -249,6 +270,7 @@ int rx51_kp_tstc(void)
 			}
 		}
 	}
+	__clear_bit(0, &twl_chip_lock);
 	return (KEYBUF_SIZE + keybuf_tail - keybuf_head)%KEYBUF_SIZE;
 }
 
@@ -256,7 +278,6 @@ int rx51_kp_getc(void)
 {
 	keybuf_head %= KEYBUF_SIZE;
 	while (!rx51_kp_tstc())
-		;
+		udelay(10000);
 	return keybuf[keybuf_head++];
 }
-
diff --git a/include/configs/nokia_rx51.h b/include/configs/nokia_rx51.h
index 6da56f5..6d93146 100644
--- a/include/configs/nokia_rx51.h
+++ b/include/configs/nokia_rx51.h
@@ -144,6 +144,7 @@
 #define CONFIG_SYS_I2C_BUS		0
 #define CONFIG_SYS_I2C_BUS_SELECT	1
 #define CONFIG_DRIVER_OMAP34XX_I2C	1
+#define CONFIG_HW_WATCHDOG
 
 /*
  * TWL4030
-- 
1.7.4.1