[U-Boot] [PATCH 20/20] arm/km: remove calls to kw_gpio_* in board_early_init_f

[Valentin Longchamp]

These functions tried to access two static tables before relocation
(board_early_init_f is executed before relocation). But these static
tables lie in the bss section which is not valid before relocation.
These accesses then overwrote some parts of u-boot binary before it was
relocated. For the kmnusa build, this results in a corrupted important
env variable (bootcmd) but it may be that some other parts of the u-boot
binary are corrupted.

This patch solves this problem by moving all the kw_gpio_* calls to
board_init, which should be early enough in the boot sequence. The only
calls that could not be moved is the one for the SOFT (bitbang) I2C, and
they have been replaced by a direct access to the GPIO dataout Control
register to set the two GPIOs as output.

Signed-off-by: Valentin Longchamp <valentin.longchamp at keymile.com>
cc: Holger Brunck <holger.brunck at keymile.com>
cc: Prafulla Wadaskar <prafulla at marvell.com>
---
 board/keymile/km_arm/km_arm.c |   34 ++++++++++++++++++++++++----------
 include/configs/km/km_arm.h   |    1 +
 2 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/board/keymile/km_arm/km_arm.c b/board/keymile/km_arm/km_arm.c
index 2581d61..c13be71 100644
--- a/board/keymile/km_arm/km_arm.c
+++ b/board/keymile/km_arm/km_arm.c
@@ -248,9 +248,27 @@ int misc_init_r(void)
 
 int board_early_init_f(void)
 {
+#if defined(CONFIG_SOFT_I2C)
 	u32 tmp;
 
+	/* set the 2 bitbang i2c pins as output gpios */
+	tmp = readl(KW_GPIO0_BASE + 4);
+	writel(tmp & (~KM_KIRKWOOD_SOFT_I2C_GPIOS) , KW_GPIO0_BASE + 4);
+#endif
+
 	kirkwood_mpp_conf(kwmpp_config, NULL);
+	return 0;
+}
+
+int board_init(void)
+{
+	/*
+	 * arch number of board
+	 */
+	gd->bd->bi_arch_number = MACH_TYPE_KM_KIRKWOOD;
+
+	/* address of boot parameters */
+	gd->bd->bi_boot_params = kw_sdram_bar(0) + 0x100;
 
 	/*
 	 * The KM_FLASH_GPIO_PIN switches between using a
@@ -259,24 +277,20 @@ int board_early_init_f(void)
 	 */
 	kw_gpio_set_valid(KM_FLASH_GPIO_PIN, 1);
 	kw_gpio_direction_output(KM_FLASH_GPIO_PIN, 1);
+
 #if defined(CONFIG_SOFT_I2C)
-	/* init the GPIO for I2C Bitbang driver */
+	/* reinit the GPIO for I2C Bitbang driver so that the now
+	 * available gpio framework is consistent. The calls to
+	 * direction output in are not necessary, they are already done in
+	 * board_early_init_f */
 	kw_gpio_set_valid(KM_KIRKWOOD_SDA_PIN, 1);
 	kw_gpio_set_valid(KM_KIRKWOOD_SCL_PIN, 1);
-	kw_gpio_direction_output(KM_KIRKWOOD_SDA_PIN, 0);
-	kw_gpio_direction_output(KM_KIRKWOOD_SCL_PIN, 0);
 #endif
+
 #if defined(CONFIG_SYS_EEPROM_WREN)
 	kw_gpio_set_valid(KM_KIRKWOOD_ENV_WP, 38);
 	kw_gpio_direction_output(KM_KIRKWOOD_ENV_WP, 1);
 #endif
-	return 0;
-}
-
-int board_init(void)
-{
-	/* address of boot parameters */
-	gd->bd->bi_boot_params = kw_sdram_bar(0) + 0x100;
 
 #if defined(CONFIG_KM_FPGA_CONFIG)
 	trigger_fpga_config();
diff --git a/include/configs/km/km_arm.h b/include/configs/km/km_arm.h
index 5fbb590..8a6b345 100644
--- a/include/configs/km/km_arm.h
+++ b/include/configs/km/km_arm.h
@@ -192,6 +192,7 @@ int get_sda(void);
 int get_scl(void);
 #define KM_KIRKWOOD_SDA_PIN	8
 #define KM_KIRKWOOD_SCL_PIN	9
+#define KM_KIRKWOOD_SOFT_I2C_GPIOS	0x0300
 #define KM_KIRKWOOD_ENV_WP	38
 
 #define I2C_ACTIVE	__set_direction(KM_KIRKWOOD_SDA_PIN, 0)
-- 
1.7.1