From fbdb24c6fe56a576e288db3acfd91dd67a6ff192 Mon Sep 17 00:00:00 2001 From: zhiayang Date: Wed, 21 Dec 2022 17:45:01 +0800 Subject: [PATCH] fix(driver): Fix potentially buggy read/write routines for max7318 driver --- app/drivers/gpio/gpio_max7318.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/app/drivers/gpio/gpio_max7318.c b/app/drivers/gpio/gpio_max7318.c index 3dcc710c..ac9c5341 100644 --- a/app/drivers/gpio/gpio_max7318.c +++ b/app/drivers/gpio/gpio_max7318.c @@ -72,17 +72,19 @@ struct max7318_drv_data { static int read_registers(const struct device *dev, uint8_t reg, uint16_t *buf) { const struct max7318_config *config = dev->config; - uint16_t data = 0; - int ret = i2c_burst_read_dt(&config->i2c_bus, reg, (uint8_t *)&data, sizeof(data)); + uint8_t data[2] = { 0 }; + int ret = i2c_burst_read_dt(&config->i2c_bus, reg, &data[0], sizeof(data)); if (ret) { - LOG_DBG("i2c_write_read FAIL %d\n", ret); + LOG_DBG("i2c_burst_read FAIL %d\n", ret); return ret; } - *buf = sys_le16_to_cpu(data); + // the first register is data[0], the second one is data[1] + // since we only ever read the PORTA registers here, it's effectively little endian. + *buf = sys_get_le16(data); - LOG_DBG("max7318: read: reg[0x%X] = 0x%X, reg[0x%X] = 0x%X", reg, (*buf & 0xFF), (reg + 1), - (*buf >> 8)); + LOG_DBG("max7318: read: reg[0x%X] = 0x%X, reg[0x%X] = 0x%X", reg, data[0], (reg + 1), + data[1]); return 0; } @@ -105,9 +107,13 @@ static int write_registers(const struct device *dev, uint8_t reg, uint16_t value LOG_DBG("max7318: write: reg[0x%X] = 0x%X, reg[0x%X] = 0x%X", reg, (value & 0xFF), (reg + 1), (value >> 8)); - uint16_t data = sys_cpu_to_le16(value); + uint8_t data[2] = { 0 }; - return i2c_burst_write_dt(&config->i2c_bus, reg, (uint8_t *)&data, sizeof(data)); + // bits 0..7 are port A, 8..15 are port B, so we should write bits 0..7 first + // -- ie. this is little endian also. + sys_put_le16(value, &data[0]); + + return i2c_burst_write_dt(&config->i2c_bus, reg, &data[0], sizeof(data)); } /**