Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754505AbbDSNc7 (ORCPT ); Sun, 19 Apr 2015 09:32:59 -0400 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:39296 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752179AbbDSN2x (ORCPT ); Sun, 19 Apr 2015 09:28:53 -0400 Message-ID: <5533AD90.8010507@kernel.org> Date: Sun, 19 Apr 2015 14:28:48 +0100 From: Jonathan Cameron User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Daniel Baluta CC: knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org Subject: Re: [PATCH 1/3] iio: magnetometer: Add support for MEMSIC MMC35240 sensor References: <1429095726-10055-1-git-send-email-daniel.baluta@intel.com> <1429095726-10055-2-git-send-email-daniel.baluta@intel.com> In-Reply-To: <1429095726-10055-2-git-send-email-daniel.baluta@intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 15051 Lines: 544 On 15/04/15 12:02, Daniel Baluta wrote: > Minimal implementation for MMC35240 3-axis magnetometer > sensor. It provides processed readings and possiblity to change > the sampling frequency. > > Signed-off-by: Daniel Baluta a couple of really minor points inline. Looks good to me. Jonathan > --- > drivers/iio/magnetometer/Kconfig | 11 + > drivers/iio/magnetometer/Makefile | 1 + > drivers/iio/magnetometer/mmc35240.c | 476 ++++++++++++++++++++++++++++++++++++ > 3 files changed, 488 insertions(+) > create mode 100644 drivers/iio/magnetometer/mmc35240.c > > diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig > index a5d6de7..7aba685 100644 > --- a/drivers/iio/magnetometer/Kconfig > +++ b/drivers/iio/magnetometer/Kconfig > @@ -47,6 +47,17 @@ config HID_SENSOR_MAGNETOMETER_3D > Say yes here to build support for the HID SENSOR > Magnetometer 3D. > > +config MMC35240 > + tristate "MEMSIC MMC35240 3-axis magnetic sensor" > + select REGMAP_I2C > + depends on I2C > + help > + Say yes here to build support for the MEMSIC MMC35240 3-axis > + magnetic sensor. > + > + To compile this driver as a module, choose M here: the module > + will be called mmc35240. > + > config IIO_ST_MAGN_3AXIS > tristate "STMicroelectronics magnetometers 3-Axis Driver" > depends on (I2C || SPI_MASTER) && SYSFS > diff --git a/drivers/iio/magnetometer/Makefile b/drivers/iio/magnetometer/Makefile > index 0f5d3c9..696a429 100644 > --- a/drivers/iio/magnetometer/Makefile > +++ b/drivers/iio/magnetometer/Makefile > @@ -6,6 +6,7 @@ > obj-$(CONFIG_AK8975) += ak8975.o > obj-$(CONFIG_MAG3110) += mag3110.o > obj-$(CONFIG_HID_SENSOR_MAGNETOMETER_3D) += hid-sensor-magn-3d.o > +obj-$(CONFIG_MMC35240) += mmc35240.o > > obj-$(CONFIG_IIO_ST_MAGN_3AXIS) += st_magn.o > st_magn-y := st_magn_core.o > diff --git a/drivers/iio/magnetometer/mmc35240.c b/drivers/iio/magnetometer/mmc35240.c > new file mode 100644 > index 0000000..c46c1f7 > --- /dev/null > +++ b/drivers/iio/magnetometer/mmc35240.c > @@ -0,0 +1,476 @@ > +/* > + * MMC35240 - MEMSIC 3-axis Magnetic Sensor > + * > + * Copyright (c) 2015, Intel Corporation. > + * > + * This file is subject to the terms and conditions of version 2 of > + * the GNU General Public License. See the file COPYING in the main > + * directory of this archive for more details. > + * > + * IIO driver for MMC35240 (7-bit I2C slave address 0x30). > + * > + * TODO: offset, ACPI, continuous measurement mode, PM > + */ > + > +#include > +#include > +#include > +#include > +#include > + > +#include > +#include > + > +#define MMC35240_DRV_NAME "mmc35240" > +#define MMC35240_REGMAP_NAME "mmc35240_regmap" > + > +#define MMC35240_REG_XOUT_L 0x00 > +#define MMC35240_REG_XOUT_H 0x01 > +#define MMC35240_REG_YOUT_L 0x02 > +#define MMC35240_REG_YOUT_H 0x03 > +#define MMC35240_REG_ZOUT_L 0x04 > +#define MMC35240_REG_ZOUT_H 0x05 > + > +#define MMC35240_REG_STATUS 0x06 > +#define MMC35240_REG_CTRL0 0x07 > +#define MMC35240_REG_CTRL1 0x08 > + > +#define MMC35240_REG_ID 0x20 > + > +#define MMC35240_STATUS_MEAS_DONE_BIT BIT(0) > + > +#define MMC35240_CTRL0_REFILL_BIT BIT(7) > +#define MMC35240_CTRL0_RESET_BIT BIT(6) > +#define MMC35240_CTRL0_SET_BIT BIT(5) > +#define MMC35240_CTRL0_CMM_BIT BIT(1) > +#define MMC35240_CTRL0_TM_BIT BIT(0) > + > +/* output resolution bits */ > +#define MMC35240_CTRL1_BW0_BIT BIT(0) > +#define MMC35240_CTRL1_BW1_BIT BIT(1) > + > +#define MMC35240_CTRL1_BW_MASK (MMC35240_CTRL1_BW0_BIT | \ > + MMC35240_CTRL1_BW1_BIT) > +#define MMC35240_CTRL1_BW_SHIFT 0 > + > +#define MMC35240_WAIT_CHARGE_PUMP 50000 /* us */ > +#define MMC53240_WAIT_SET_RESET 1000 /* us */ > + > +enum mmc35240_resolution { > + MMC35240_16_BITS_SLOW = 0, /* 100 Hz */ > + MMC35240_16_BITS_FAST, /* 200 Hz */ > + MMC35240_14_BITS, /* 333 Hz */ > + MMC35240_12_BITS, /* 666 Hz */ > + MMC35240_MAX_BITS /* this must be last */ > +}; > + > +enum mmc35240_axis { > + AXIS_X = 0, > + AXIS_Y, > + AXIS_Z, > +}; > + > +static const struct { > + int sens[3]; /* sensitivity per X, Y, Z axis */ > + int nfo; /* null field output */ > +} mmc35240_props_table[] = { > + /* 16 bits, 100Hz ODR */ > + { > + {1024, 1024, 770}, > + 32768, > + }, > + /* 16 bits, 200Hz ODR */ > + { > + {1024, 1024, 770}, > + 32768, > + }, > + /* 14 bits, 333Hz ODR */ > + { > + {256, 256, 193}, > + 8192, > + }, > + /* 12 bits, 666Hz ODR */ > + { > + {64, 64, 48}, > + 2048, > + }, > +}; > + > +struct mmc35240_data { > + struct i2c_client *client; > + struct mutex mutex; > + struct regmap *regmap; > + enum mmc35240_resolution res; > +}; > + > +int mmc35240_samp_freq[] = {100, 200, 333, 666}; > + > +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("100 200 333 666"); > + > +#define MMC35240_CHANNEL(_axis) { \ > + .type = IIO_MAGN, \ > + .modified = 1, \ > + .channel2 = IIO_MOD_ ## _axis, \ > + .address = AXIS_ ## _axis, \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \ > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ), \ > +} > + > +static const struct iio_chan_spec mmc35240_channels[] = { > + MMC35240_CHANNEL(X), > + MMC35240_CHANNEL(Y), > + MMC35240_CHANNEL(Z), > +}; > + > +static struct attribute *mmc35240_attributes[] = { > + &iio_const_attr_sampling_frequency_available.dev_attr.attr, > +}; > + > +static const struct attribute_group mmc35240_attribute_group = { > + .attrs = mmc35240_attributes, > +}; > + > +static int mmc35240_get_samp_freq_index(struct mmc35240_data *data, > + int val, int val2) > +{ > + int i; > + > + for (i = 0; i < ARRAY_SIZE(mmc35240_samp_freq); i++) > + if (mmc35240_samp_freq[i] == val) > + return i; > + return -EINVAL; > +} > + > +static int mmc35240_hw_set(struct mmc35240_data *data, bool set) > +{ > + int ret; > + u8 coil_bit; > + > + /* > + * Recharge the capacitor at VCAP pin, requested to be issued > + * before a SET/RESET command. > + */ > + ret = regmap_update_bits(data->regmap, MMC35240_REG_CTRL0, > + MMC35240_CTRL0_REFILL_BIT, > + MMC35240_CTRL0_REFILL_BIT); > + if (ret < 0) > + return ret; > + usleep_range(MMC35240_WAIT_CHARGE_PUMP, MMC35240_WAIT_CHARGE_PUMP + 1); > + > + if (set) > + coil_bit = MMC35240_CTRL0_SET_BIT; > + else > + coil_bit = MMC35240_CTRL0_RESET_BIT; > + > + return regmap_update_bits(data->regmap, MMC35240_REG_CTRL0, > + MMC35240_CTRL0_REFILL_BIT, > + coil_bit); > +} > + > +static int mmc35240_init(struct mmc35240_data *data) > +{ > + int ret; > + unsigned int reg_id; > + > + ret = regmap_read(data->regmap, MMC35240_REG_ID, ®_id); > + if (ret < 0) { > + dev_err(&data->client->dev, "Error reading product id\n"); > + return ret; > + } > + > + dev_info(&data->client->dev, "MMC35240 chip id %x\n", reg_id); > + > + /* > + * make sure we restore sensor characteristics, by doing > + * a RESET/SET sequence > + */ > + ret = mmc35240_hw_set(data, false); > + if (ret < 0) > + return ret; > + usleep_range(MMC53240_WAIT_SET_RESET, MMC53240_WAIT_SET_RESET + 1); > + > + ret = mmc35240_hw_set(data, true); > + if (ret < 0) > + return ret; > + > + /* set default sampling frequency */ > + return regmap_update_bits(data->regmap, MMC35240_REG_CTRL1, > + MMC35240_CTRL1_BW_MASK, > + data->res << MMC35240_CTRL1_BW_SHIFT); > +} > + > +static int mmc35240_take_measurement(struct mmc35240_data *data) > +{ > + int ret, tries = 100; > + unsigned int reg_status; > + > + ret = regmap_write(data->regmap, MMC35240_REG_CTRL0, > + MMC35240_CTRL0_TM_BIT); > + if (ret < 0) > + return ret; > + > + while (tries-- > 0) { > + ret = regmap_read(data->regmap, MMC35240_REG_STATUS, > + ®_status); > + if (ret < 0) > + return ret; > + if (reg_status & MMC35240_STATUS_MEAS_DONE_BIT) > + break; > + msleep(20); > + } > + > + if (tries < 0) { > + dev_err(&data->client->dev, "data not ready\n"); > + return -EIO; > + } > + > + return 0; > +} > + > +static int mmc35240_read_measurement(struct mmc35240_data *data, __le16 buf[3]) > +{ > + int ret; > + Why this seperation into read_measurement and take_measurement? > + ret = mmc35240_take_measurement(data); > + if (ret < 0) > + return ret; > + > + return regmap_bulk_read(data->regmap, MMC35240_REG_XOUT_L, (u8 *)buf, > + 3 * sizeof(__be16)); > +} > + > +int mmc35240_raw_to_gauss(struct mmc35240_data *data, int index, __le16 buf[], > + int *val, int *val2) > +{ > + int raw_x, raw_y, raw_z; > + int sens_x, sens_y, sens_z; > + int nfo; > + > + raw_x = le16_to_cpu(buf[AXIS_X]); > + raw_y = le16_to_cpu(buf[AXIS_Y]); > + raw_z = le16_to_cpu(buf[AXIS_Z]); > + > + sens_x = mmc35240_props_table[data->res].sens[AXIS_X]; > + sens_y = mmc35240_props_table[data->res].sens[AXIS_Y]; > + sens_z = mmc35240_props_table[data->res].sens[AXIS_Z]; > + > + nfo = mmc35240_props_table[data->res].nfo; > + > + switch (index) { > + case AXIS_X: > + *val = (raw_x - nfo) / sens_x; > + *val2 = ((raw_x - nfo) % sens_x) * 1000000; > + break; > + case AXIS_Y: > + *val = (raw_y - nfo) / sens_y - (raw_z - nfo) / sens_z; > + *val2 = (((raw_y - nfo) % sens_y - (raw_z - nfo) % sens_z)) > + * 1000000; > + break; > + case AXIS_Z: > + *val = (raw_y - nfo) / sens_y + (raw_z - nfo) / sens_z; > + *val2 = (((raw_y - nfo) % sens_y + (raw_z - nfo) % sens_z)) > + * 1000000; > + break; > + default: > + return -EINVAL; > + } > + return 0; > +} > + > +static int mmc35240_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, int *val, > + int *val2, long mask) > +{ > + struct mmc35240_data *data = iio_priv(indio_dev); > + int ret, i; > + unsigned int reg; > + __le16 buf[3]; > + > + switch (mask) { > + case IIO_CHAN_INFO_PROCESSED: > + mutex_lock(&data->mutex); > + ret = mmc35240_read_measurement(data, buf); > + mutex_unlock(&data->mutex); > + if (ret < 0) > + return ret; > + ret = mmc35240_raw_to_gauss(data, chan->address, > + buf, val, val2); > + if (ret < 0) > + return ret; > + return IIO_VAL_INT_PLUS_MICRO; > + case IIO_CHAN_INFO_SAMP_FREQ: > + mutex_lock(&data->mutex); > + ret = regmap_read(data->regmap, MMC35240_REG_CTRL1, ®); > + mutex_unlock(&data->mutex); > + if (ret < 0) > + return ret; > + > + i = (reg & MMC35240_CTRL1_BW_MASK) >> MMC35240_CTRL1_BW_SHIFT; > + if (i < 0 || i > ARRAY_SIZE(mmc35240_samp_freq)) > + return -EINVAL; > + > + *val = mmc35240_samp_freq[i]; > + *val2 = 0; > + return IIO_VAL_INT_PLUS_MICRO; > + default: > + return -EINVAL; > + } > +} > + > +static int mmc35240_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, int val, > + int val2, long mask) > +{ > + struct mmc35240_data *data = iio_priv(indio_dev); > + int i, ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_SAMP_FREQ: > + i = mmc35240_get_samp_freq_index(data, val, val2); > + if (i < 0) > + return -EINVAL; > + mutex_lock(&data->mutex); > + ret = regmap_update_bits(data->regmap, MMC35240_REG_CTRL1, > + MMC35240_CTRL1_BW_MASK, > + i << MMC35240_CTRL1_BW_SHIFT); > + mutex_unlock(&data->mutex); > + return ret; > + default: > + return -EINVAL; > + } > +} > + > +static const struct iio_info mmc35240_info = { > + .driver_module = THIS_MODULE, > + .read_raw = mmc35240_read_raw, > + .write_raw = mmc35240_write_raw, > + .attrs = &mmc35240_attribute_group, > +}; > + > +static bool mmc35240_is_writeable_reg(struct device *dev, unsigned int reg) > +{ > + switch (reg) { > + case MMC35240_REG_CTRL0: > + case MMC35240_REG_CTRL1: > + return true; > + default: > + return false; > + } > +} > + > +static bool mmc35240_is_readable_reg(struct device *dev, unsigned int reg) > +{ > + switch (reg) { > + case MMC35240_REG_XOUT_L: > + case MMC35240_REG_XOUT_H: > + case MMC35240_REG_YOUT_L: > + case MMC35240_REG_YOUT_H: > + case MMC35240_REG_ZOUT_L: > + case MMC35240_REG_ZOUT_H: > + case MMC35240_REG_STATUS: > + case MMC35240_REG_ID: > + return true; > + default: > + return false; > + } > +} > + > +static bool mmc35240_is_volatile_reg(struct device *dev, unsigned int reg) > +{ > + switch (reg) { > + case MMC35240_REG_CTRL0: > + case MMC35240_REG_CTRL1: > + return false; > + default: > + return true; > + } > +} > + > +static struct reg_default mmc35240_reg_defaults[] = { > + { MMC35240_REG_CTRL0, 0x00 }, > + { MMC35240_REG_CTRL1, 0x00 }, > +}; > + > +static const struct regmap_config mmc35240_regmap_config = { > + .name = MMC35240_REGMAP_NAME, > + > + .reg_bits = 8, > + .val_bits = 8, > + > + .max_register = MMC35240_REG_ID, > + .cache_type = REGCACHE_FLAT, > + > + .writeable_reg = mmc35240_is_writeable_reg, > + .readable_reg = mmc35240_is_readable_reg, > + .volatile_reg = mmc35240_is_volatile_reg, > + > + .reg_defaults = mmc35240_reg_defaults, > + .num_reg_defaults = ARRAY_SIZE(mmc35240_reg_defaults), > +}; > + > +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; > + int ret; > + > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > + if (!indio_dev) > + return -ENOMEM; > + > + regmap = devm_regmap_init_i2c(client, &mmc35240_regmap_config); > + if (IS_ERR(regmap)) { > + dev_err(&client->dev, "regmap initialization failed\n"); > + return PTR_ERR(regmap); > + } > + > + data = iio_priv(indio_dev); > + i2c_set_clientdata(client, indio_dev); If you are dropping the remove, you don't actually need the above either. > + data->client = client; > + data->regmap = regmap; > + data->res = MMC35240_16_BITS_SLOW; > + > + mutex_init(&data->mutex); > + > + indio_dev->dev.parent = &client->dev; > + indio_dev->info = &mmc35240_info; > + indio_dev->name = MMC35240_DRV_NAME; > + indio_dev->channels = mmc35240_channels; > + indio_dev->num_channels = ARRAY_SIZE(mmc35240_channels); > + indio_dev->modes = INDIO_DIRECT_MODE; > + > + ret = mmc35240_init(data); > + if (ret < 0) { > + dev_err(&client->dev, "mmc35240 chip init failed\n"); > + return ret; > + } > + return devm_iio_device_register(&client->dev, indio_dev); > +} > + > +static int mmc35240_remove(struct i2c_client *client) > +{ > + return 0; > +} > + > +static const struct i2c_device_id mmc35240_id[] = { > + {"MMC35240", 0}, > + {} > +}; > +MODULE_DEVICE_TABLE(i2c, mmc35240_id); > + > +static struct i2c_driver mmc35240_driver = { > + .driver = { > + .name = MMC35240_DRV_NAME, > + }, > + .probe = mmc35240_probe, > + .remove = mmc35240_remove, > + .id_table = mmc35240_id, > +}; > + > +module_i2c_driver(mmc35240_driver); > + > +MODULE_AUTHOR("Daniel Baluta "); > +MODULE_DESCRIPTION("MEMSIC MMC35240 magnetic sensor driver"); > +MODULE_LICENSE("GPL v2"); > -- 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/