From 73f3bc6da506711302bb67572440eb84b1ec4a2c Mon Sep 17 00:00:00 2001 From: Mike Looijmans Date: Wed, 6 Mar 2019 08:31:48 +0100 Subject: iio:chemical:bme680: Fix SPI read interface The SPI interface implementation was completely broken. When using the SPI interface, there are only 7 address bits, the upper bit is controlled by a page select register. The core needs access to both ranges, so implement register read/write for both regions. The regmap paging functionality didn't agree with a register that needs to be read and modified, so I implemented a custom paging algorithm. This fixes that the device wouldn't even probe in SPI mode. The SPI interface then isn't different from I2C, merged them into the core, and the I2C/SPI named registers are no longer needed. Implemented register value caching for the registers to reduce the I2C/SPI data transfers considerably. The calibration set reads as all zeroes until some undefined point in time, and I couldn't determine what makes it valid. The datasheet mentions these registers but does not provide any hints on when they become valid, and they aren't even enumerated in the memory map. So check the calibration and retry reading it from the device after each measurement until it provides something valid. Despite the size this is suitable for a stable backport given that it seems the SPI support never worked. Signed-off-by: Mike Looijmans Fixes: 1b3bd8592780 ("iio: chemical: Add support for Bosch BME680 sensor"); Cc: Signed-off-by: Jonathan Cameron --- drivers/iio/chemical/bme680_i2c.c | 21 --------------------- 1 file changed, 21 deletions(-) (limited to 'drivers/iio/chemical/bme680_i2c.c') diff --git a/drivers/iio/chemical/bme680_i2c.c b/drivers/iio/chemical/bme680_i2c.c index b2f805b6b36a..de9c9e3d23ea 100644 --- a/drivers/iio/chemical/bme680_i2c.c +++ b/drivers/iio/chemical/bme680_i2c.c @@ -23,8 +23,6 @@ static int bme680_i2c_probe(struct i2c_client *client, { struct regmap *regmap; const char *name = NULL; - unsigned int val; - int ret; regmap = devm_regmap_init_i2c(client, &bme680_regmap_config); if (IS_ERR(regmap)) { @@ -33,25 +31,6 @@ static int bme680_i2c_probe(struct i2c_client *client, return PTR_ERR(regmap); } - ret = regmap_write(regmap, BME680_REG_SOFT_RESET_I2C, - BME680_CMD_SOFTRESET); - if (ret < 0) { - dev_err(&client->dev, "Failed to reset chip\n"); - return ret; - } - - ret = regmap_read(regmap, BME680_REG_CHIP_I2C_ID, &val); - if (ret < 0) { - dev_err(&client->dev, "Error reading I2C chip ID\n"); - return ret; - } - - if (val != BME680_CHIP_ID_VAL) { - dev_err(&client->dev, "Wrong chip ID, got %x expected %x\n", - val, BME680_CHIP_ID_VAL); - return -ENODEV; - } - if (id) name = id->name; -- cgit