Revert "stm32: Change USART port to USART6 for stm32f746 discovery board"

Per Vikas' request, the problem this commit is supposed to be solving is
something he doesn't see and further this introduces additional hardware
requirements.

This reverts commit 4b2fd720.
Signed-off-by: NTom Rini <trini@konsulko.com>

arch/arm/include/asm/arch-stm32f7/stm32_periph.h

@@ -17,13 +17,11 @@
 enum periph_id {
 	UART1_GPIOA_9_10 = 0,
 	UART2_GPIOD_5_6,
-	UART6_GPIOC_6_7,
 };
 
 enum periph_clock {
 	USART1_CLOCK_CFG = 0,
 	USART2_CLOCK_CFG,
-	USART6_CLOCK_CFG,
 	GPIO_A_CLOCK_CFG,
 	GPIO_B_CLOCK_CFG,
 	GPIO_C_CLOCK_CFG,

arch/arm/mach-stm32/stm32f7/clock.c

@@ -245,9 +245,6 @@ void clock_setup(int peripheral)
 	case USART1_CLOCK_CFG:
 		setbits_le32(RCC_BASE + RCC_APB2ENR, RCC_ENR_USART1EN);
 		break;
-	case USART6_CLOCK_CFG:
-		setbits_le32(RCC_BASE + RCC_APB2ENR, RCC_ENR_USART6EN);
-		break;
 	case GPIO_A_CLOCK_CFG:
 		setbits_le32(RCC_BASE + RCC_AHB1ENR, RCC_ENR_GPIO_A_EN);
 		break;

board/st/stm32f746-disco/stm32f746-disco.c

@@ -32,7 +32,7 @@ const struct stm32_gpio_ctl gpio_ctl_usart = {
 	.otype = STM32_GPIO_OTYPE_PP,
 	.speed = STM32_GPIO_SPEED_50M,
 	.pupd = STM32_GPIO_PUPD_UP,
-	.af = STM32_GPIO_AF8
+	.af = STM32_GPIO_AF7
 };
 
 const struct stm32_gpio_ctl gpio_ctl_fmc = {
@@ -251,8 +251,8 @@ int dram_init(void)
 }
 
 static const struct stm32_gpio_dsc usart_gpio[] = {
-	{STM32_GPIO_PORT_C, STM32_GPIO_PIN_6},	/* TX */
-	{STM32_GPIO_PORT_C, STM32_GPIO_PIN_7},	/* RX */
+	{STM32_GPIO_PORT_A, STM32_GPIO_PIN_9},	/* TX */
+	{STM32_GPIO_PORT_B, STM32_GPIO_PIN_7},	/* RX */
 };
 
 int uart_setup_gpio(void)
@@ -260,7 +260,8 @@ int uart_setup_gpio(void)
 	int i;
 	int rv = 0;
 
-	clock_setup(GPIO_C_CLOCK_CFG);
+	clock_setup(GPIO_A_CLOCK_CFG);
+	clock_setup(GPIO_B_CLOCK_CFG);
 	for (i = 0; i < ARRAY_SIZE(usart_gpio); i++) {
 		rv = stm32_gpio_config(&usart_gpio[i], &gpio_ctl_usart);
 		if (rv)
@@ -272,7 +273,7 @@ out:
 }
 
 static const struct stm32x7_serial_platdata serial_platdata = {
-	.base = (struct stm32_usart *)USART6_BASE,
+	.base = (struct stm32_usart *)USART1_BASE,
 	.clock = CONFIG_SYS_CLK_FREQ,
 };
 
@@ -291,7 +292,7 @@ int board_early_init_f(void)
 	int res;
 
 	res = uart_setup_gpio();
-	clock_setup(USART6_CLOCK_CFG);
+	clock_setup(USART1_CLOCK_CFG);
 	if (res)
 		return res;