marvell/uboot/drivers/video/spi-lcd/readid.c

#include <common.h>
#include <malloc.h>
#include <asm/gpio.h>
#include "lcd.h"

#define LCD_SUB_ID_CNT	3
static u8 sub_id_reg[LCD_SUB_ID_CNT] = {0xDA, 0xDB, 0xDC};

struct lcd_sub_id {
		u8 val;
		u8 mask;
};

struct lcd_info {
		const char *name;
		u8 type;
		struct lcd_sub_id sub_id[LCD_SUB_ID_CNT];
};

static struct lcd_info lcd_info[] = {
		{"st7735", PANEL_ST7735, {{0x7C, 0x7F}, {0x89, 0xFE}, {0xF0, 0xFF}}},
		{"gc9102", PANEL_GC9102, {{0x00, 0xFF}, {0x91, 0xFF}, {0x02, 0xFF}}},
		{"gc9106", PANEL_GC9106, {{0x00, 0xFF}, {0x91, 0xFF}, {0x06, 0xFF}}},
};

static inline void SPI_DELAY(u16 a)
{
		while (a--)
				nop();
}

static inline void LCD_SELECT_DATA_OR_CMD(u16 a)
{
#ifndef CONFIG_SPI_LCD_3WIRE
		gpio_direction_output(CONFIG_SPI_LCD_RS_PIN, a);
#endif
}

void LCD_SEND_DATA(void)
{
		LCD_SELECT_DATA_OR_CMD(1);
}

void LCD_SEND_CMD(void)
{
		LCD_SELECT_DATA_OR_CMD(0);
}

static inline void SPI_CS(u16 a)
{
		gpio_direction_output(CONFIG_SPI_LCD_CS_PIN, a);
}

static inline void SPI_SCL(u16 a)
{
		gpio_direction_output(CONFIG_SPI_LCD_SCL_PIN, a);
}

static inline void SPI_TX(u16 a)
{
		gpio_direction_output(CONFIG_SPI_LCD_TX_PIN, a);
}

static inline u8 SPI_READ(void)
{
		return !!gpio_get_value(CONFIG_SPI_LCD_TX_PIN);
}

static inline void SPI_TX_TO_RX(void)
{
		gpio_direction_input(CONFIG_SPI_LCD_TX_PIN);
}

static u8 __lcd_readid(u8 reg)
{
		LCD_SEND_CMD();
		SPI_CS(0);
		u16 cmd = reg;
		int i;
		int bits, mask;
		/* May need to tune this delay for different panel.
		 * For ST7735, this delay can be set to 0.
		*/
		u16 delay = 0;

#ifdef CONFIG_SPI_LCD_3WIRE
		bits = 9;
		mask = 0x100;
#else
		bits = 8;
		mask = 0x80;
#endif
		for (i = 0; i < bits; i++)
		{
				SPI_TX(cmd & mask);
				SPI_DELAY(delay);
				SPI_SCL(1);
				SPI_DELAY(delay);
				SPI_SCL(0);
				cmd <<= 1;
		}

		SPI_TX_TO_RX();

		cmd = 0;
		for (i = 0; i < 8; i++)
		{
				SPI_DELAY(delay);
				SPI_SCL(1);
				cmd <<= 1;
				cmd |= SPI_READ();
				SPI_SCL(0);
		}

		SPI_CS(1);
		printf("LCD ID 0x%x: 0x%x\n", reg, cmd);
		return cmd;
}

static u8 check_id(u8 id, u8 mask, u8 val)
{
		if ((val & mask) == (id & mask))
				return 0;
		return 1;
}

u8 lcd_gettype(void)
{
		u32 id = 0;
		int i;
		u8 id1, id2, id3;
		u8 type = 0;

		lcd_readid_pin_config();
		lcd_power(1);
		lcd_reset();
		for (i = 0; i < LCD_SUB_ID_CNT; i++) {
				id <<= 8;
				id |= __lcd_readid(sub_id_reg[i]);
		}
		lcd_readid_pin_restore();

		id1 = (id & 0xFF0000) >> 16;
		id2 = (id & 0xFF00) >> 8;
		id3 = id & 0xFF;

		for (i = 0; i < sizeof(lcd_info) / sizeof(lcd_info[0]); i++) {
				if (check_id(id1, lcd_info[i].sub_id[0].mask, lcd_info[i].sub_id[0].val) == 0 &&
						check_id(id2, lcd_info[i].sub_id[1].mask, lcd_info[i].sub_id[1].val) == 0 &&
						check_id(id3, lcd_info[i].sub_id[2].mask, lcd_info[i].sub_id[2].val) == 0)
				{
						printf("LCD Name: %s, ID: 0x%x, Type: %d\n",
								lcd_info[i].name, id, lcd_info[i].type);
						type = lcd_info[i].type;
						goto end;
				}
		}

		printf("UNSUPPORTTED LCD ID: 0x%x, Type: 0\n", id);
end:
		return type;
}