Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752047AbbHQT2s (ORCPT ); Mon, 17 Aug 2015 15:28:48 -0400 Received: from ns.pmeerw.net ([84.19.176.92]:37148 "EHLO pmeerw.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750873AbbHQT2o (ORCPT ); Mon, 17 Aug 2015 15:28:44 -0400 Date: Mon, 17 Aug 2015 21:28:41 +0200 (CEST) From: Peter Meerwald To: Teodora Baluta cc: jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de, daniel.baluta@intel.com, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4] iio: magnetometer: add mmc34160 magnetometer driver In-Reply-To: <1439826269-14849-1-git-send-email-teodora.baluta@intel.com> Message-ID: References: <1439826269-14849-1-git-send-email-teodora.baluta@intel.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10862 Lines: 386 On Mon, 17 Aug 2015, Teodora Baluta wrote: > This patch adds support for the MMC34160 3-axis magnetometer driver. The > MMC31460 magnetometer driver uses the same register map as MMC35240 with > different specifications for sensitivity. > > According to Memsic specification, for the MMC31460 sensor, there is no > need to apply compensation to the read values. Also, the MMC34160 sensor > does not use the same formula as MMC35240 for transforming raw data into > mgauss, and the current formula is based on the input driver (mmc3416x) > provided by Memsic. comments below > Signed-off-by: Teodora Baluta > --- > Changes since v3: > - rebased to apply correctly > - include bits that went missing from v2 to v3 > - remove return variable from mmc34160_raw_to_mgauss function > > drivers/iio/magnetometer/Kconfig | 4 +- > drivers/iio/magnetometer/mmc35240.c | 205 ++++++++++++++++++++++++++++-------- > 2 files changed, 162 insertions(+), 47 deletions(-) > > diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig > index 868abad..df3f4cc 100644 > --- a/drivers/iio/magnetometer/Kconfig > +++ b/drivers/iio/magnetometer/Kconfig > @@ -70,8 +70,8 @@ config MMC35240 > select REGMAP_I2C > depends on I2C > help > - Say yes here to build support for the MEMSIC MMC35240 3-axis > - magnetic sensor. > + Say yes here to build support for the MEMSIC MMC35240 and MMC34160 > + 3-axis magnetic sensors. > > To compile this driver as a module, choose M here: the module > will be called mmc35240. > diff --git a/drivers/iio/magnetometer/mmc35240.c b/drivers/iio/magnetometer/mmc35240.c > index 176e14a..e4fc5e4 100644 > --- a/drivers/iio/magnetometer/mmc35240.c > +++ b/drivers/iio/magnetometer/mmc35240.c > @@ -83,6 +83,20 @@ > > #define MMC35240_OTP_START_ADDR 0x1B > > +#define MMC35240_CHIP_ID 0x08 > +#define MMC34160_CHIP_ID 0x06 > + > +enum mmc35240_chipset { > + MMC35240, > + MMC34160, > + MMC_MAX_CHIPS > +}; > + > +static u8 chip_ids[MMC_MAX_CHIPS] = { mmc35240_ prefix missing > + MMC35240_CHIP_ID, > + MMC34160_CHIP_ID, > +}; > + > enum mmc35240_resolution { > MMC35240_16_BITS_SLOW = 0, /* 7.92 ms */ > MMC35240_16_BITS_FAST, /* 4.08 ms */ > @@ -99,27 +113,53 @@ enum mmc35240_axis { > static const struct { > int sens[3]; /* sensitivity per X, Y, Z axis */ > int nfo; /* null field output */ > -} mmc35240_props_table[] = { > - /* 16 bits, 125Hz ODR */ > - { > - {1024, 1024, 1024}, > - 32768, > - }, > - /* 16 bits, 250Hz ODR */ > - { > - {1024, 1024, 770}, > - 32768, > - }, > - /* 14 bits, 450Hz ODR */ > +} mmc35240_props_table[MMC_MAX_CHIPS][4] = { > + /* MMC35240 */ > { > - {256, 256, 193}, > - 8192, > + /* 16 bits, 125Hz ODR */ > + { > + {1024, 1024, 1024}, > + 32768, > + }, > + /* 16 bits, 250Hz ODR */ > + { > + {1024, 1024, 770}, > + 32768, > + }, > + /* 14 bits, 450Hz ODR */ > + { > + {256, 256, 193}, > + 8192, > + }, > + /* 12 bits, 800Hz ODR */ > + { > + {64, 64, 48}, > + 2048, > + }, > }, > - /* 12 bits, 800Hz ODR */ > + /* MMC34160 */ > { > - {64, 64, 48}, > - 2048, > - }, > + /* 16 bits, 125Hz ODR */ > + { > + {2048, 2048, 2048}, > + 32768, > + }, > + /* 16 bits, 250Hz ODR */ > + { > + {2048, 2048, 2048}, > + 32768, > + }, > + /* 14 bits, 450Hz ODR */ > + { > + {512, 512, 512}, > + 8192, > + }, > + /* 12 bits, 800Hz ODR */ > + { > + {128, 128, 128}, > + 2048, > + }, > + } > }; > > struct mmc35240_data { > @@ -131,6 +171,7 @@ struct mmc35240_data { > /* OTP compensation */ > int axis_coef[3]; > int axis_scale[3]; > + enum mmc35240_chipset chipset; > }; > > static const struct { > @@ -206,6 +247,16 @@ static int mmc35240_hw_set(struct mmc35240_data *data, bool set) > > } > > +static inline bool mmc35240_needs_compensation(enum mmc35240_chipset chipset) maybe drop inline and let the compiler figure out > +{ > + switch (chipset) { > + case MMC35240: > + return true; > + default: > + return false; > + } > +} > + > static int mmc35240_init(struct mmc35240_data *data) > { > int ret, y_convert, z_convert; > @@ -220,6 +271,11 @@ static int mmc35240_init(struct mmc35240_data *data) > > dev_dbg(&data->client->dev, "MMC35240 chip id %x\n", reg_id); > > + if (reg_id != chip_ids[data->chipset]) { > + dev_err(&data->client->dev, "Invalid chip %x\n", ret); > + return -ENODEV; > + } > + > /* > * make sure we restore sensor characteristics, by doing > * a SET/RESET sequence, the axis polarity being naturally > @@ -241,6 +297,9 @@ static int mmc35240_init(struct mmc35240_data *data) > if (ret < 0) > return ret; > > + if (!mmc35240_needs_compensation(data->chipset)) > + return 0; > + > ret = regmap_bulk_read(data->regmap, MMC35240_OTP_START_ADDR, > (u8 *)otp_data, sizeof(otp_data)); > if (ret < 0) > @@ -302,9 +361,37 @@ static int mmc35240_read_measurement(struct mmc35240_data *data, __le16 buf[3]) > 3 * sizeof(__le16)); > } > > +static int mmc34160_raw_to_mgauss(int raw[3], int sens[3], int nfo, > + int index, int *val) > +{ > + return (raw[index] - nfo) * 1000 / sens[index]; > +} > + > +static int mmc35240_raw_to_mgauss(int raw[3], int sens[3], int nfo, > + int index, int *val) > +{ > + switch (index) { > + case AXIS_X: > + *val = (raw[AXIS_X] - nfo) * 1000 / sens[AXIS_X]; > + break; > + case AXIS_Y: > + *val = (raw[AXIS_Y] - nfo) * 1000 / sens[AXIS_Y] - > + (raw[AXIS_Z] - nfo) * 1000 / sens[AXIS_Z]; > + break; > + case AXIS_Z: > + *val = (raw[AXIS_Y] - nfo) * 1000 / sens[AXIS_Y] + > + (raw[AXIS_Z] - nfo) * 1000 / sens[AXIS_Z]; > + break; > + default: > + return -EINVAL; > + } > + > + return 0; > +} > + > /** > - * mmc35240_raw_to_mgauss - convert raw readings to milli gauss. Also apply > - compensation for output value. > + * memsic_raw_to_mgauss - convert raw readings to milli gauss. Also apply > + compensation for output value. why the name change? > * > * @data: device private data > * @index: axis index for which we want the conversion > @@ -313,40 +400,42 @@ static int mmc35240_read_measurement(struct mmc35240_data *data, __le16 buf[3]) > * > * Returns: 0 in case of success, -EINVAL when @index is not valid > */ > -static int mmc35240_raw_to_mgauss(struct mmc35240_data *data, int index, > - __le16 buf[], int *val) > +static int memsic_raw_to_mgauss(struct mmc35240_data *data, int index, > + __le16 buf[], int *val) > { > int raw[3]; > int sens[3]; > int nfo; > + int ret; > + int id = data->chipset; > > raw[AXIS_X] = le16_to_cpu(buf[AXIS_X]); > raw[AXIS_Y] = le16_to_cpu(buf[AXIS_Y]); > raw[AXIS_Z] = le16_to_cpu(buf[AXIS_Z]); > > - sens[AXIS_X] = mmc35240_props_table[data->res].sens[AXIS_X]; > - sens[AXIS_Y] = mmc35240_props_table[data->res].sens[AXIS_Y]; > - sens[AXIS_Z] = mmc35240_props_table[data->res].sens[AXIS_Z]; > + sens[AXIS_X] = mmc35240_props_table[id][data->res].sens[AXIS_X]; > + sens[AXIS_Y] = mmc35240_props_table[id][data->res].sens[AXIS_Y]; > + sens[AXIS_Z] = mmc35240_props_table[id][data->res].sens[AXIS_Z]; > > - nfo = mmc35240_props_table[data->res].nfo; > > - switch (index) { > - case AXIS_X: > - *val = (raw[AXIS_X] - nfo) * 1000 / sens[AXIS_X]; > - break; > - case AXIS_Y: > - *val = (raw[AXIS_Y] - nfo) * 1000 / sens[AXIS_Y] - > - (raw[AXIS_Z] - nfo) * 1000 / sens[AXIS_Z]; > - break; > - case AXIS_Z: > - *val = (raw[AXIS_Y] - nfo) * 1000 / sens[AXIS_Y] + > - (raw[AXIS_Z] - nfo) * 1000 / sens[AXIS_Z]; > - break; > + nfo = mmc35240_props_table[id][data->res].nfo; > + > + switch (id) { > + case MMC35240: > + ret = mmc35240_raw_to_mgauss(raw, sens, nfo, index, val); > + if (ret < 0) > + return ret; > + > + /* apply OTP compensation */ > + *val = (*val) * data->axis_coef[index] / > + data->axis_scale[index]; > + > + return 0; > + case MMC34160: > + return mmc34160_raw_to_mgauss(raw, sens, nfo, index, val); > default: > return -EINVAL; > } > - /* apply OTP compensation */ > - *val = (*val) * data->axis_coef[index] / data->axis_scale[index]; > > return 0; > } > @@ -367,7 +456,7 @@ static int mmc35240_read_raw(struct iio_dev *indio_dev, > mutex_unlock(&data->mutex); > if (ret < 0) > return ret; > - ret = mmc35240_raw_to_mgauss(data, chan->address, buf, val); > + ret = memsic_raw_to_mgauss(data, chan->address, buf, val); > if (ret < 0) > return ret; > return IIO_VAL_INT; > @@ -485,12 +574,27 @@ static const struct regmap_config mmc35240_regmap_config = { > .num_reg_defaults = ARRAY_SIZE(mmc35240_reg_defaults), > }; > > +static const char *mmc35240_match_acpi_device(struct device *dev, > + enum mmc35240_chipset *chipset) > +{ > + const struct acpi_device_id *id; > + > + id = acpi_match_device(dev->driver->acpi_match_table, dev); > + if (!id) > + return NULL; > + > + *chipset = (enum mmc35240_chipset)id->driver_data; > + > + return dev_name(dev); > +} > + > static int mmc35240_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > struct mmc35240_data *data; > struct iio_dev *indio_dev; > struct regmap *regmap; > + const char *name; > int ret; > > indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > @@ -509,11 +613,20 @@ static int mmc35240_probe(struct i2c_client *client, > data->regmap = regmap; > data->res = MMC35240_16_BITS_SLOW; > > + if (id) { > + data->chipset = (enum mmc35240_chipset)(id->driver_data); > + name = id->name; > + } else if (ACPI_HANDLE(&client->dev)) { > + name = mmc35240_match_acpi_device(&client->dev, > + &data->chipset); > + } else > + return -ENODEV; > + > mutex_init(&data->mutex); > > indio_dev->dev.parent = &client->dev; > indio_dev->info = &mmc35240_info; > - indio_dev->name = MMC35240_DRV_NAME; > + indio_dev->name = name; > indio_dev->channels = mmc35240_channels; > indio_dev->num_channels = ARRAY_SIZE(mmc35240_channels); > indio_dev->modes = INDIO_DIRECT_MODE; > @@ -566,14 +679,16 @@ static const struct of_device_id mmc35240_of_match[] = { > MODULE_DEVICE_TABLE(of, mmc35240_of_match); > > static const struct acpi_device_id mmc35240_acpi_match[] = { > - {"MMC35240", 0}, > + {"MMC35240", MMC35240}, > + {"MMC34160", MMC34160}, > { }, > }; > MODULE_DEVICE_TABLE(acpi, mmc35240_acpi_match); > > static const struct i2c_device_id mmc35240_id[] = { > - {"mmc35240", 0}, > - {} > + {"mmc35240", MMC35240}, > + {"mmc34160", MMC34160}, > + { } > }; > MODULE_DEVICE_TABLE(i2c, mmc35240_id); > > -- Peter Meerwald +43-664-2444418 (mobile) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/