Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752845AbbGaQdG (ORCPT ); Fri, 31 Jul 2015 12:33:06 -0400 Received: from ns.pmeerw.net ([84.19.176.92]:59598 "EHLO pmeerw.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751659AbbGaQdE (ORCPT ); Fri, 31 Jul 2015 12:33:04 -0400 Date: Fri, 31 Jul 2015 18:33:01 +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 1/3] iio: accel: add support for mxc4005 accelerometer In-Reply-To: <1438356340-13306-2-git-send-email-teodora.baluta@intel.com> Message-ID: References: <1438356340-13306-1-git-send-email-teodora.baluta@intel.com> <1438356340-13306-2-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: 12233 Lines: 485 On Fri, 31 Jul 2015, Teodora Baluta wrote: > This patch adds support for Memsic MXC4005XC 3-axis accelerometer. The > current implementation is a minimal one as it adds raw readings for the > three axes and setting scale from userspace. some comments below > Signed-off-by: Teodora Baluta > --- > drivers/iio/accel/Kconfig | 11 ++ > drivers/iio/accel/Makefile | 2 + > drivers/iio/accel/mxc4005.c | 373 ++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 386 insertions(+) > create mode 100644 drivers/iio/accel/mxc4005.c > > diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig > index 00e7bcb..7f534a3 100644 > --- a/drivers/iio/accel/Kconfig > +++ b/drivers/iio/accel/Kconfig > @@ -137,6 +137,17 @@ config MMA9553 > To compile this driver as a module, choose M here: the module > will be called mma9553. > > +config MXC4005 > + tristate "Memsic MXC4005XC 3-Axis Accelerometer Driver" > + depends on I2C > + select REGMAP_I2C > + help > + Say yes here to build support for the Memsic MXC4005XC 3-axis > + accelerometer. > + > + To compile this driver as a module, choose M. The module will be > + called mxc4005. > + > config STK8312 > tristate "Sensortek STK8312 3-Axis Accelerometer Driver" > depends on I2C > diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile > index ebd2675..020dda0 100644 > --- a/drivers/iio/accel/Makefile > +++ b/drivers/iio/accel/Makefile > @@ -14,6 +14,8 @@ obj-$(CONFIG_MMA9551_CORE) += mma9551_core.o > obj-$(CONFIG_MMA9551) += mma9551.o > obj-$(CONFIG_MMA9553) += mma9553.o > > +obj-$(CONFIG_MXC4005) += mxc4005.o > + > obj-$(CONFIG_STK8312) += stk8312.o > obj-$(CONFIG_STK8BA50) += stk8ba50.o > > diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c > new file mode 100644 > index 0000000..0f0410c > --- /dev/null > +++ b/drivers/iio/accel/mxc4005.c > @@ -0,0 +1,373 @@ > +/* > + * 3-axis accelerometer driver for MXC4005XC Memsic sensor > + * > + * Copyright (c) 2014, Intel Corporation. > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define MXC4005_DRV_NAME "mxc4005" > +#define MXC4005_REGMAP_NAME "mxc4005_regmap" > + > +#define MXC4005_REG_XOUT_UPPER 0x03 > +#define MXC4005_REG_XOUT_LOWER 0x04 > +#define MXC4005_REG_YOUT_UPPER 0x05 > +#define MXC4005_REG_YOUT_LOWER 0x06 > +#define MXC4005_REG_ZOUT_UPPER 0x07 > +#define MXC4005_REG_ZOUT_LOWER 0x08 > + > +#define MXC4005_REG_CONTROL 0x0D > +#define MXC4005_REG_CONTROL_MASK_FSR GENMASK(6, 5) > +#define MXC4005_CONTROL_FSR_SHIFT 5 > + > +#define MXC4005_REG_DEVICE_ID 0x0E > + > +#define MXC4005_AXIS_TO_REG(axis) (MXC4005_REG_XOUT_UPPER + (axis * 2)) maybe parenthesis around (axis) > + > +enum mxc4005_axis { > + AXIS_X, > + AXIS_Y, > + AXIS_Z, > +}; > + > +enum mxc4005_range { > + MXC4005_RANGE_2G, > + MXC4005_RANGE_4G, > + MXC4005_RANGE_8G, > +}; > + > +struct mxc4005_data { > + struct i2c_client *client; > + struct mutex mutex; > + struct regmap *regmap; > +}; > + > +/* > + * MXC4005 can operate in the following ranges: > + * +/- 2G, 4G, 8G (the default +/-2G) > + * > + * (2 + 2) * 9.81 / (2^12 - 1) = 0.009582 > + * (4 + 4) * 9.81 / (2^12 - 1) = 0.019164 > + * (8 + 8) * 9.81 / (2^12 - 1) = 0.038329 > + */ > +static const struct { > + u8 range; > + u16 scale; scale should be int > +} mxc4005_scale_table[] = { > + {MXC4005_RANGE_2G, 9582}, > + {MXC4005_RANGE_4G, 19164}, > + {MXC4005_RANGE_8G, 38329}, > +}; > + > + > +static IIO_CONST_ATTR(in_accel_scale_available, "0.009582 0.019164 0.038329"); > + > +static struct attribute *mxc4005_attributes[] = { > + &iio_const_attr_in_accel_scale_available.dev_attr.attr, > + NULL, > +}; > + > +static const struct attribute_group mxc4005_attrs_group = { > + .attrs = mxc4005_attributes, > +}; > + > +static bool mxc4005_is_readable_reg(struct device *dev, unsigned int reg) > +{ > + switch (reg) { > + case MXC4005_REG_XOUT_UPPER: > + case MXC4005_REG_XOUT_LOWER: > + case MXC4005_REG_YOUT_UPPER: > + case MXC4005_REG_YOUT_LOWER: > + case MXC4005_REG_ZOUT_UPPER: > + case MXC4005_REG_ZOUT_LOWER: > + case MXC4005_REG_DEVICE_ID: > + case MXC4005_REG_CONTROL: > + return true; > + default: > + return false; > + } > +} > + > +static bool mxc4005_is_writeable_reg(struct device *dev, unsigned int reg) > +{ > + switch (reg) { > + case MXC4005_REG_CONTROL: > + return true; > + default: > + return false; > + } > +} > + > +static const struct regmap_config mxc4005_regmap_config = { > + .name = MXC4005_DRV_NAME, > + > + .reg_bits = 8, > + .val_bits = 8, > + > + .max_register = MXC4005_REG_DEVICE_ID, > + .cache_type = REGCACHE_NONE, > + > + .readable_reg = mxc4005_is_readable_reg, > + .writeable_reg = mxc4005_is_writeable_reg, > +}; > + > +static int mxc4005_read_axis(struct mxc4005_data *data, > + int axis) > +{ > + u16 reg; be16 > + int ret; > + > + ret = regmap_bulk_read(data->regmap, MXC4005_AXIS_TO_REG(axis), > + (u8 *) ®, 2); sizeof(reg) probably > + if (ret < 0) { > + dev_err(&data->client->dev, "failed to read axis %d\n", axis); > + return ret; > + } > + > + return reg; > +} > + > +static int mxc4005_read_scale(struct mxc4005_data *data) > +{ > + unsigned int reg; > + int ret; > + int i; > + > + ret = regmap_read(data->regmap, MXC4005_REG_CONTROL, ®); > + if (ret < 0) { > + dev_err(&data->client->dev, "failed to read reg_control"); \n missing > + return ret; > + } > + > + i = reg >> MXC4005_CONTROL_FSR_SHIFT; maybe mask the relevant bits... > + > + if (i < 0 || i >= ARRAY_SIZE(mxc4005_scale_table)) > + return -EINVAL; .. instead of returning an error > + > + return mxc4005_scale_table[i].scale; > +} > + > +static int mxc4005_set_scale(struct mxc4005_data *data, int val) > +{ > + int i; > + int ret; > + int scale; > + > + for (i = 0; i < ARRAY_SIZE(mxc4005_scale_table); i++) { > + if (mxc4005_scale_table[i].scale == val) { > + scale = i << MXC4005_CONTROL_FSR_SHIFT; reg would be a better name for variable scale (and consistent with read_scale()), could be moved to local scope > + ret = regmap_update_bits(data->regmap, > + MXC4005_REG_CONTROL, > + MXC4005_REG_CONTROL_MASK_FSR, > + scale); > + if (ret < 0) > + dev_err(&data->client->dev, > + "failed to write reg_control %d\n", > + ret); ret is only shown here, but not for read_scale(); maybe "failed to write reg_control, ret = %d\n" would be clearer > + return ret; > + } > + } > + > + return -EINVAL; > +} > + > +static int mxc4005_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + struct mxc4005_data *data = iio_priv(indio_dev); > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + switch (chan->type) { > + case IIO_ACCEL: > + if (iio_buffer_enabled(indio_dev)) > + return -EBUSY; > + > + mutex_lock(&data->mutex); > + ret = mxc4005_read_axis(data, chan->address); > + mutex_unlock(&data->mutex); > + if (ret < 0) > + return ret; > + ret = be16_to_cpu(ret); I'd move the be16_to_cpu() to read_axis() > + *val = sign_extend32(ret >> 4, 11); > + return IIO_VAL_INT; > + default: > + return -EINVAL; > + } > + case IIO_CHAN_INFO_SCALE: > + *val = 0; maybe move this assignment down where you set val2 > + mutex_lock(&data->mutex); > + ret = mxc4005_read_scale(data); > + mutex_unlock(&data->mutex); > + if (ret < 0) > + return ret; > + > + *val2 = ret; > + return IIO_VAL_INT_PLUS_MICRO; > + default: > + return -EINVAL; > + } > +} > + > +static int mxc4005_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, int val2, long mask) > +{ > + struct mxc4005_data *data = iio_priv(indio_dev); > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_SCALE: > + if (val != 0) > + return -EINVAL; > + > + mutex_lock(&data->mutex); > + ret = mxc4005_set_scale(data, val2); > + mutex_unlock(&data->mutex); > + break; return ret; > + default: > + ret = -EINVAL; return -EINVAL; > + } > + > + return ret; > +} > + > +static const struct iio_info mxc4005_info = { > + .driver_module = THIS_MODULE, > + .read_raw = mxc4005_read_raw, > + .write_raw = mxc4005_write_raw, > + .attrs = &mxc4005_attrs_group, > +}; > + > +#define MXC4005_CHANNEL(_axis) { \ > + .type = IIO_ACCEL, \ > + .modified = 1, \ > + .channel2 = IIO_MOD_##_axis, \ > + .address = AXIS_##_axis, \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ > +} > + > +static const struct iio_chan_spec mxc4005_channels[] = { > + MXC4005_CHANNEL(X), > + MXC4005_CHANNEL(Y), > + MXC4005_CHANNEL(Z), > +}; > + > +static int mxc4005_chip_init(struct mxc4005_data *data) > +{ > + int ret; > + unsigned int reg; > + > + ret = regmap_read(data->regmap, MXC4005_REG_DEVICE_ID, ®); > + if (ret < 0) { > + dev_err(&data->client->dev, "failed to read chip id\n"); > + return ret; > + } > + > + dev_dbg(&data->client->dev, "MXC4005 chip id %d\n", reg); probably better to format as %02x > + > + return 0; > +} > + > +static int mxc4005_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct mxc4005_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, &mxc4005_regmap_config); > + if (IS_ERR(regmap)) { > + dev_err(&client->dev, "failed to initialize regmap\n"); > + return PTR_ERR(regmap); > + } > + > + data = iio_priv(indio_dev); > + i2c_set_clientdata(client, indio_dev); > + data->client = client; > + data->regmap = regmap; > + > + ret = mxc4005_chip_init(data); > + if (ret < 0) { > + dev_err(&client->dev, "failed to init chip\n"); > + return ret; > + } > + > + mutex_init(&data->mutex); > + > + indio_dev->dev.parent = &client->dev; > + indio_dev->channels = mxc4005_channels; > + indio_dev->num_channels = ARRAY_SIZE(mxc4005_channels); > + indio_dev->name = MXC4005_DRV_NAME; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->info = &mxc4005_info; > + > + ret = iio_device_register(indio_dev); > + if (ret < 0) { > + dev_err(&client->dev, > + "unable to register iio device %d\n", ret); > + return ret; > + } > + > + return 0; > +} > + > +static int mxc4005_remove(struct i2c_client *client) > +{ > + struct iio_dev *indio_dev = i2c_get_clientdata(client); > + > + iio_device_unregister(indio_dev); > + > + return 0; > +} > + > +static const struct acpi_device_id mxc4005_acpi_match[] = { > + {"MXC4005", 0}, > + { }, > +}; > +MODULE_DEVICE_TABLE(acpi, mxc4005_acpi_match); > + > +static const struct i2c_device_id mxc4005_id[] = { > + {"mxc4005", 0}, > + { }, > +}; > + > +MODULE_DEVICE_TABLE(i2c, mxc4005_id); > + > +static struct i2c_driver mxc4005_driver = { > + .driver = { > + .name = MXC4005_DRV_NAME, > + .acpi_match_table = ACPI_PTR(mxc4005_acpi_match), > + }, > + .probe = mxc4005_probe, > + .remove = mxc4005_remove, > + .id_table = mxc4005_id, > +}; > + > +module_i2c_driver(mxc4005_driver); > + > +MODULE_AUTHOR("Teodora Baluta "); > +MODULE_LICENSE("GPL v2"); > +MODULE_DESCRIPTION("MXC4005 3-axis accelerometer driver"); > -- 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/