i.MX28: Implement boot pads sampling and reporting

This patch implements code that samples i.MX28 boot pads and reports boot mode
accordingly.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Detlev Zundel <dzu@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>

arch/arm/cpu/arm926ejs/mx28/mx28.c

@@ -185,8 +185,12 @@ int arch_cpu_init(void)
 #if defined(CONFIG_DISPLAY_CPUINFO)
 int print_cpuinfo(void)
 {
+	struct mx28_spl_data *data = (struct mx28_spl_data *)
+		((CONFIG_SYS_TEXT_BASE - sizeof(struct mx28_spl_data)) & ~0xf);
+
 	printf("Freescale i.MX28 family at %d MHz\n",
 			mxc_get_clock(MXC_ARM_CLK) / 1000000);
+	printf("BOOT:  %s\n", mx28_boot_modes[data->boot_mode_idx].mode);
 	return 0;
 }
 #endif

arch/arm/cpu/arm926ejs/mx28/spl_boot.c

@@ -29,6 +29,7 @@
 #include <asm/arch/iomux-mx28.h>
 #include <asm/arch/imx-regs.h>
 #include <asm/arch/sys_proto.h>
+#include <asm/gpio.h>
 
 #include "mx28_init.h"
 
@@ -47,11 +48,56 @@ void early_delay(int delay)
 		;
 }
 
+#define	MUX_CONFIG_BOOTMODE_PAD	(MXS_PAD_3V3 | MXS_PAD_4MA | MXS_PAD_NOPULL)
+const iomux_cfg_t iomux_boot[] = {
+	MX28_PAD_LCD_D00__GPIO_1_0 | MUX_CONFIG_BOOTMODE_PAD,
+	MX28_PAD_LCD_D01__GPIO_1_1 | MUX_CONFIG_BOOTMODE_PAD,
+	MX28_PAD_LCD_D02__GPIO_1_2 | MUX_CONFIG_BOOTMODE_PAD,
+	MX28_PAD_LCD_D03__GPIO_1_3 | MUX_CONFIG_BOOTMODE_PAD,
+	MX28_PAD_LCD_D04__GPIO_1_4 | MUX_CONFIG_BOOTMODE_PAD,
+	MX28_PAD_LCD_D05__GPIO_1_5 | MUX_CONFIG_BOOTMODE_PAD,
+};
+
+uint8_t mx28_get_bootmode_index(void)
+{
+	uint8_t bootmode = 0;
+	int i;
+	uint8_t masked;
+
+	/* Setup IOMUX of bootmode pads to GPIO */
+	mxs_iomux_setup_multiple_pads(iomux_boot, ARRAY_SIZE(iomux_boot));
+
+	/* Setup bootmode pins as GPIO input */
+	gpio_direction_input(MX28_PAD_LCD_D00__GPIO_1_0);
+	gpio_direction_input(MX28_PAD_LCD_D01__GPIO_1_1);
+	gpio_direction_input(MX28_PAD_LCD_D02__GPIO_1_2);
+	gpio_direction_input(MX28_PAD_LCD_D03__GPIO_1_3);
+	gpio_direction_input(MX28_PAD_LCD_D04__GPIO_1_4);
+	gpio_direction_input(MX28_PAD_LCD_D05__GPIO_1_5);
+
+	/* Read bootmode pads */
+	bootmode |= (gpio_get_value(MX28_PAD_LCD_D00__GPIO_1_0) ? 1 : 0) << 0;
+	bootmode |= (gpio_get_value(MX28_PAD_LCD_D01__GPIO_1_1) ? 1 : 0) << 1;
+	bootmode |= (gpio_get_value(MX28_PAD_LCD_D02__GPIO_1_2) ? 1 : 0) << 2;
+	bootmode |= (gpio_get_value(MX28_PAD_LCD_D03__GPIO_1_3) ? 1 : 0) << 3;
+	bootmode |= (gpio_get_value(MX28_PAD_LCD_D04__GPIO_1_4) ? 1 : 0) << 4;
+	bootmode |= (gpio_get_value(MX28_PAD_LCD_D05__GPIO_1_5) ? 1 : 0) << 5;
+
+	for (i = 0; i < ARRAY_SIZE(mx28_boot_modes); i++) {
+		masked = bootmode & mx28_boot_modes[i].boot_mask;
+		if (masked == mx28_boot_modes[i].boot_pads)
+			break;
+	}
+
+	return i;
+}
+
 void mx28_common_spl_init(const iomux_cfg_t *iomux_setup,
 			const unsigned int iomux_size)
 {
 	struct mx28_spl_data *data = (struct mx28_spl_data *)
 		((CONFIG_SYS_TEXT_BASE - sizeof(struct mx28_spl_data)) & ~0xf);
+	uint8_t bootmode = mx28_get_bootmode_index();
 
 	mxs_iomux_setup_multiple_pads(iomux_setup, iomux_size);
 	mx28_power_init();
@@ -59,6 +105,8 @@ void mx28_common_spl_init(const iomux_cfg_t *iomux_setup,
 	mx28_mem_init();
 	data->mem_dram_size = mx28_mem_get_size();
 
+	data->boot_mode_idx = bootmode;
+
 	mx28_power_wait_pswitch();
 }
 

arch/arm/include/asm/arch-mx28/sys_proto.h

@@ -39,7 +39,33 @@ void mx28_common_spl_init(const iomux_cfg_t *iomux_setup,
 			const unsigned int iomux_size);
 #endif
 
+struct mx28_pair {
+	uint8_t	boot_pads;
+	uint8_t boot_mask;
+	const char *mode;
+};
+
+static const struct mx28_pair mx28_boot_modes[] = {
+	{ 0x00, 0x0f, "USB #0" },
+	{ 0x01, 0x1f, "I2C #0, master, 3V3" },
+	{ 0x11, 0x1f, "I2C #0, master, 1V8" },
+	{ 0x02, 0x1f, "SSP SPI #2, master, 3V3 NOR" },
+	{ 0x12, 0x1f, "SSP SPI #2, master, 1V8 NOR" },
+	{ 0x03, 0x1f, "SSP SPI #3, master, 3V3 NOR" },
+	{ 0x13, 0x1f, "SSP SPI #3, master, 1V8 NOR" },
+	{ 0x04, 0x1f, "NAND, 3V3" },
+	{ 0x14, 0x1f, "NAND, 1V8" },
+	{ 0x08, 0x1f, "SSP SPI #3, master, 3V3 EEPROM" },
+	{ 0x18, 0x1f, "SSP SPI #3, master, 1V8 EEPROM" },
+	{ 0x09, 0x1f, "SSP SD/MMC #0, 3V3" },
+	{ 0x19, 0x1f, "SSP SD/MMC #0, 1V8" },
+	{ 0x0a, 0x1f, "SSP SD/MMC #1, 3V3" },
+	{ 0x1a, 0x1f, "SSP SD/MMC #1, 1V8" },
+	{ 0x00, 0x00, "Reserved/Unknown/Wrong" },
+};
+
 struct mx28_spl_data {
+	uint8_t		boot_mode_idx;
 	uint32_t	mem_dram_size;
 };
 

include/configs/m28evk.h

@@ -54,6 +54,7 @@
 #define	CONFIG_SPL_LDSCRIPT	"arch/arm/cpu/arm926ejs/mx28/u-boot-spl.lds"
 #define	CONFIG_SPL_LIBCOMMON_SUPPORT
 #define	CONFIG_SPL_LIBGENERIC_SUPPORT
+#define	CONFIG_SPL_GPIO_SUPPORT
 
 /*
  * U-Boot Commands

include/configs/mx28evk.h

@@ -46,6 +46,7 @@
 #define CONFIG_SPL_LDSCRIPT	"arch/arm/cpu/arm926ejs/mx28/u-boot-spl.lds"
 #define CONFIG_SPL_LIBCOMMON_SUPPORT
 #define CONFIG_SPL_LIBGENERIC_SUPPORT
+#define CONFIG_SPL_GPIO_SUPPORT
 
 /*
  * U-Boot Commands