| Message ID | 1558404814-26078-3-git-send-email-eajames@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: Add driver for Infineon DPS310 | expand |
On Mon, 20 May 2019 21:13:33 -0500 Eddie James <eajames@linux.ibm.com> wrote: > From: Christopher Bostic <cbostic@linux.vnet.ibm.com> > > Add a manufacturer's suggested workaround to deal with early revisions > of chip that don't indicate correct temperature. Readings can be in the > ~60C range when they should be in the ~20's. > > Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com> > Signed-off-by: Joel Stanley <joel@jms.id.au> > Signed-off-by: Eddie James <eajames@linux.ibm.com> > Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > --- > drivers/iio/pressure/dps310.c | 52 +++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 50 insertions(+), 2 deletions(-) > > diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c > index 9acfccb..a093e3a 100644 > --- a/drivers/iio/pressure/dps310.c > +++ b/drivers/iio/pressure/dps310.c > @@ -53,7 +53,6 @@ > #define DPS310_RESET 0x0c > #define DPS310_RESET_MAGIC 0x09 > #define DPS310_COEF_BASE 0x10 > -#define DPS310_COEF_SRC 0x28 > > /* Make sure sleep time is <= 20ms for usleep_range */ > #define DPS310_POLL_SLEEP_US(t) min(20000, (t) / 8) > @@ -234,6 +233,10 @@ static bool dps310_is_writeable_reg(struct device *dev, unsigned int reg) > case DPS310_MEAS_CFG: > case DPS310_CFG_REG: > case DPS310_RESET: > + /* No documentation available on the registers below */ > + case 0x0e: > + case 0x0f: > + case 0x62: > return true; > default: > return false; > @@ -250,6 +253,7 @@ static bool dps310_is_volatile_reg(struct device *dev, unsigned int reg) > case DPS310_TMP_B1: > case DPS310_TMP_B2: > case DPS310_MEAS_CFG: > + case 0x32: /* No documentation available on this register */ > return true; > default: > return false; > @@ -360,7 +364,7 @@ static void dps310_reset(void *action_data) > .writeable_reg = dps310_is_writeable_reg, > .volatile_reg = dps310_is_volatile_reg, > .cache_type = REGCACHE_RBTREE, > - .max_register = DPS310_COEF_SRC, > + .max_register = 0x62, /* No documentation available on this register */ > }; > > static const struct iio_info dps310_info = { > @@ -368,6 +372,46 @@ static void dps310_reset(void *action_data) > .write_raw = dps310_write_raw, > }; > > +/* > + * Some verions of chip will read temperatures in the ~60C range when > + * its actually ~20C. This is the manufacturer recommended workaround > + * to correct the issue. The registers used below are undocumented. > + */ > +static int dps310_temp_workaround(struct dps310_data *data) > +{ > + int rc; > + int reg; > + > + rc = regmap_read(data->regmap, 0x32, ®); > + if (rc < 0) > + return rc; > + > + /* > + * If bit 1 is set then the device is okay, and the workaround does not > + * need to be applied > + */ > + if (reg & BIT(1)) > + return 0; > + > + rc = regmap_write(data->regmap, 0x0e, 0xA5); > + if (rc < 0) > + return rc; > + > + rc = regmap_write(data->regmap, 0x0f, 0x96); > + if (rc < 0) > + return rc; > + > + rc = regmap_write(data->regmap, 0x62, 0x02); > + if (rc < 0) > + return rc; > + > + rc = regmap_write(data->regmap, 0x0e, 0x00); > + if (rc < 0) > + return rc; > + > + return regmap_write(data->regmap, 0x0f, 0x00); > +} > + > static int dps310_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > @@ -439,6 +483,10 @@ static int dps310_probe(struct i2c_client *client, > if (rc < 0) > return rc; > > + rc = dps310_temp_workaround(data); > + if (rc < 0) > + return rc; > + > rc = devm_iio_device_register(&client->dev, iio); > if (rc) > return rc;
diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c index 9acfccb..a093e3a 100644 --- a/drivers/iio/pressure/dps310.c +++ b/drivers/iio/pressure/dps310.c @@ -53,7 +53,6 @@ #define DPS310_RESET 0x0c #define DPS310_RESET_MAGIC 0x09 #define DPS310_COEF_BASE 0x10 -#define DPS310_COEF_SRC 0x28 /* Make sure sleep time is <= 20ms for usleep_range */ #define DPS310_POLL_SLEEP_US(t) min(20000, (t) / 8) @@ -234,6 +233,10 @@ static bool dps310_is_writeable_reg(struct device *dev, unsigned int reg) case DPS310_MEAS_CFG: case DPS310_CFG_REG: case DPS310_RESET: + /* No documentation available on the registers below */ + case 0x0e: + case 0x0f: + case 0x62: return true; default: return false; @@ -250,6 +253,7 @@ static bool dps310_is_volatile_reg(struct device *dev, unsigned int reg) case DPS310_TMP_B1: case DPS310_TMP_B2: case DPS310_MEAS_CFG: + case 0x32: /* No documentation available on this register */ return true; default: return false; @@ -360,7 +364,7 @@ static void dps310_reset(void *action_data) .writeable_reg = dps310_is_writeable_reg, .volatile_reg = dps310_is_volatile_reg, .cache_type = REGCACHE_RBTREE, - .max_register = DPS310_COEF_SRC, + .max_register = 0x62, /* No documentation available on this register */ }; static const struct iio_info dps310_info = { @@ -368,6 +372,46 @@ static void dps310_reset(void *action_data) .write_raw = dps310_write_raw, }; +/* + * Some verions of chip will read temperatures in the ~60C range when + * its actually ~20C. This is the manufacturer recommended workaround + * to correct the issue. The registers used below are undocumented. + */ +static int dps310_temp_workaround(struct dps310_data *data) +{ + int rc; + int reg; + + rc = regmap_read(data->regmap, 0x32, ®); + if (rc < 0) + return rc; + + /* + * If bit 1 is set then the device is okay, and the workaround does not + * need to be applied + */ + if (reg & BIT(1)) + return 0; + + rc = regmap_write(data->regmap, 0x0e, 0xA5); + if (rc < 0) + return rc; + + rc = regmap_write(data->regmap, 0x0f, 0x96); + if (rc < 0) + return rc; + + rc = regmap_write(data->regmap, 0x62, 0x02); + if (rc < 0) + return rc; + + rc = regmap_write(data->regmap, 0x0e, 0x00); + if (rc < 0) + return rc; + + return regmap_write(data->regmap, 0x0f, 0x00); +} + static int dps310_probe(struct i2c_client *client, const struct i2c_device_id *id) { @@ -439,6 +483,10 @@ static int dps310_probe(struct i2c_client *client, if (rc < 0) return rc; + rc = dps310_temp_workaround(data); + if (rc < 0) + return rc; + rc = devm_iio_device_register(&client->dev, iio); if (rc) return rc;