Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752676AbbHRLcd (ORCPT ); Tue, 18 Aug 2015 07:32:33 -0400 Received: from mga11.intel.com ([192.55.52.93]:17754 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750928AbbHRLcb (ORCPT ); Tue, 18 Aug 2015 07:32:31 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,701,1432623600"; d="scan'208";a="544021841" Date: Tue, 18 Aug 2015 14:32:15 +0300 From: Teodora Baluta To: Peter Meerwald 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 Message-ID: <20150818113215.GA22724@hard-bop> References: <1439826269-14849-1-git-send-email-teodora.baluta@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 12318 Lines: 407 On Mon, Aug 17, 2015 at 09:28:41PM +0200, Peter Meerwald wrote: > 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 Hi Peter, Thanks for the review! I'll address the comments in a v5 patch. Some answers 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 Did not take into account that the compiler can decide this for us, though it seems pretty straight-forward it will inline it. I'll drop the inline then. > > > +{ > > + 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? Used the prefix for chip specific conversion - see mmc35240_raw_to_mgauss and mmc34160_raw_to_mgauss. I could keep the prefix for this one function and rename it to mmc35240_raw_to_mgauss_comp (since it applies compensation as well), remove the mmc34160_raw_to_mgauss function and put the formula directly and keep the mmc35240_raw_to_mgauss as it is. Would that be better? > > > * > > * @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/