diff options
Diffstat (limited to 'drivers/regulator/rpi-panel-attiny-regulator.c')
| -rw-r--r-- | drivers/regulator/rpi-panel-attiny-regulator.c | 35 |
1 files changed, 34 insertions, 1 deletions
diff --git a/drivers/regulator/rpi-panel-attiny-regulator.c b/drivers/regulator/rpi-panel-attiny-regulator.c index 6e408a4b2c21..f7df0f4b2f87 100644 --- a/drivers/regulator/rpi-panel-attiny-regulator.c +++ b/drivers/regulator/rpi-panel-attiny-regulator.c @@ -250,6 +250,39 @@ static void attiny_gpio_set(struct gpio_chip *gc, unsigned int off, int val) mutex_unlock(&state->lock); } +static int attiny_i2c_read(struct i2c_client *client, u8 reg, unsigned int *buf) +{ + struct i2c_msg msgs[1]; + u8 addr_buf[1] = { reg }; + u8 data_buf[1] = { 0, }; + int ret; + + /* Write register address */ + msgs[0].addr = client->addr; + msgs[0].flags = 0; + msgs[0].len = ARRAY_SIZE(addr_buf); + msgs[0].buf = addr_buf; + + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (ret != ARRAY_SIZE(msgs)) + return -EIO; + + usleep_range(5000, 10000); + + /* Read data from register */ + msgs[0].addr = client->addr; + msgs[0].flags = I2C_M_RD; + msgs[0].len = 1; + msgs[0].buf = data_buf; + + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (ret != ARRAY_SIZE(msgs)) + return -EIO; + + *buf = data_buf[0]; + return 0; +} + /* * I2C driver interface functions */ @@ -280,7 +313,7 @@ static int attiny_i2c_probe(struct i2c_client *i2c, goto error; } - ret = regmap_read(regmap, REG_ID, &data); + ret = attiny_i2c_read(i2c, REG_ID, &data); if (ret < 0) { dev_err(&i2c->dev, "Failed to read REG_ID reg: %d\n", ret); goto error; |