[U-Boot] [PATCH v3 11/11] arm/km: remove calls to kw_gpio_* in board_early_init_f

[Holger Brunck]

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they have been replaced by a direct access to the GPIO dataout Control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>
---
changes for v3:
  -  nothing
changes for v2:
  - fix comment syntax

 board/keymile/km_arm/km_arm.c |   43 ++++++++++++++++++++++++++--------------
 include/configs/km/km_arm.h   |    1 +
 2 files changed, 29 insertions(+), 15 deletions(-)

diff --git a/board/keymile/km_arm/km_arm.c b/board/keymile/km_arm/km_arm.c
index eb691f9..ac290fa 100644
--- a/board/keymile/km_arm/km_arm.c
+++ b/board/keymile/km_arm/km_arm.c
@@ -243,38 +243,51 @@ 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)
+{
 	/*
-	 * The FLASH_GPIO_PIN switches between using a
+	 * 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
 	 * NAND or a SPI FLASH. Set this pin on start
 	 * to NAND mode.
 	 */
-	tmp = readl(KW_GPIO0_BASE);
-	writel(tmp | FLASH_GPIO_PIN , KW_GPIO0_BASE);
-	tmp = readl(KW_GPIO0_BASE + 4);
-	writel(tmp & (~FLASH_GPIO_PIN) , KW_GPIO0_BASE + 4);
+	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 1a5f04b..3aa5ca1 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