diff options
| -rw-r--r-- | realtek_mst_i2c_spi.c | 57 |
1 files changed, 43 insertions, 14 deletions
diff --git a/realtek_mst_i2c_spi.c b/realtek_mst_i2c_spi.c index d1f72273..63ff510c 100644 --- a/realtek_mst_i2c_spi.c +++ b/realtek_mst_i2c_spi.c @@ -46,6 +46,8 @@ #define OPCODE_READ 3 #define OPCODE_WRITE 2 +#define GPIO_CONFIG_ADDRESS 0x104F +#define GPIO_VALUE_ADDRESS 0xFE3F struct realtek_mst_i2c_spi_data { int fd; @@ -146,27 +148,54 @@ static int realtek_mst_i2c_spi_reset_mpu(int fd) return ret; } -static int realtek_mst_i2c_spi_disable_protection(int fd) +static int realtek_mst_i2c_spi_select_indexed_register(int fd, uint16_t address) { int ret = 0; - uint8_t val = 0; - // 0xAB[2:0] = b001 ret |= realtek_mst_i2c_spi_write_register(fd, 0xF4, 0x9F); - ret |= realtek_mst_i2c_spi_write_register(fd, 0xF5, 0x10); - ret |= realtek_mst_i2c_spi_write_register(fd, 0xF4, 0xAB); + ret |= realtek_mst_i2c_spi_write_register(fd, 0xF5, address >> 8); + ret |= realtek_mst_i2c_spi_write_register(fd, 0xF4, address & 0xFF); - ret |= realtek_mst_i2c_spi_read_register(fd, 0xF5, &val); + return ret; +} - ret |= realtek_mst_i2c_spi_write_register(fd, 0xF4, 0x9F); - ret |= realtek_mst_i2c_spi_write_register(fd, 0xF5, 0x10); - ret |= realtek_mst_i2c_spi_write_register(fd, 0xF4, 0xAB); +static int realtek_mst_i2c_spi_write_indexed_register(int fd, uint16_t address, uint8_t val) +{ + int ret = 0; + + ret |= realtek_mst_i2c_spi_select_indexed_register(fd, address); + ret |= realtek_mst_i2c_spi_write_register(fd, 0xF5, val); + + return ret; +} + +static int realtek_mst_i2c_spi_read_indexed_register(int fd, uint16_t address, uint8_t *val) +{ + int ret = 0; + + ret |= realtek_mst_i2c_spi_select_indexed_register(fd, address); + ret |= realtek_mst_i2c_spi_read_register(fd, 0xF5, val); + + return ret; +} + + +/* Toggle the GPIO pin 88, this could be routed to different controls like write + * protection or a led. */ +static int realtek_mst_i2c_spi_toggle_gpio_88_strap(int fd, bool toggle) +{ + int ret = 0; + uint8_t val = 0; - ret |= realtek_mst_i2c_spi_write_register(fd, 0xF5, (val & 0xF8) | 0x01); + /* Read register 0x104F into val. */ + ret |= realtek_mst_i2c_spi_read_indexed_register(fd, GPIO_CONFIG_ADDRESS, &val); + /* Write 0x104F[3:0] = b0001 to enable the toggle of pin value. */ + ret |= realtek_mst_i2c_spi_write_indexed_register(fd, GPIO_CONFIG_ADDRESS, (val & 0xF0) | 0x01); - /* Set pin value to high, 0xFFD7[0] = 1. */ - ret |= realtek_mst_i2c_spi_read_register(fd, 0xD7, &val); - ret |= realtek_mst_i2c_spi_write_register(fd, 0xD7, (val & 0xFE) | 0x01); + /* Read register 0xFE3F into val. */ + ret |= realtek_mst_i2c_spi_read_indexed_register(fd, GPIO_VALUE_ADDRESS, &val); + /* Write 0xFE3F[0] = b|toggle| to toggle pin value to low/high. */ + ret |= realtek_mst_i2c_spi_write_indexed_register(fd, GPIO_VALUE_ADDRESS, (val & 0xFE) | toggle); return ret; } @@ -333,7 +362,7 @@ static int realtek_mst_i2c_spi_write_256(struct flashctx *flash, const uint8_t * if (fd < 0) return SPI_GENERIC_ERROR; - ret = realtek_mst_i2c_spi_disable_protection(fd); + ret = realtek_mst_i2c_spi_toggle_gpio_88_strap(fd, true); if (ret) return ret; |