From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:51489 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751005AbaECLMO (ORCPT ); Sat, 3 May 2014 07:12:14 -0400 Message-ID: <5364CF6A.1030507@kernel.org> Date: Sat, 03 May 2014 12:13:46 +0100 From: Jonathan Cameron MIME-Version: 1.0 To: Peter Meerwald , linux-iio@vger.kernel.org Subject: Re: [PATCH] iio: Add Freescale MMA8452Q 3-axis accelerometer driver References: <1399020695-29822-1-git-send-email-pmeerw@pmeerw.net> <1399020695-29822-2-git-send-email-pmeerw@pmeerw.net> In-Reply-To: <1399020695-29822-2-git-send-email-pmeerw@pmeerw.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 02/05/14 09:51, Peter Meerwald wrote: > 3-axis accelerometer sensor (2/4/8 g) with 12-bit resolution > and I2C interface > > many extra features are unsupported (freefall detection, orientation > change, autosleep) > > datasheet is here: > http://cache.freescale.com/files/sensors/doc/data_sheet/MMA8452Q.pdf > > v2: (thanks to Jonathan Cameron) > * use ARRAY_SIZE() > > Signed-off-by: Peter Meerwald Fair enough on your responses in the cover letter. Applied to the togreg branch of iio.git Thanks, Jonathan > --- > drivers/iio/accel/Kconfig | 12 ++ > drivers/iio/accel/Makefile | 1 + > drivers/iio/accel/mma8452.c | 439 ++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 452 insertions(+) > create mode 100644 drivers/iio/accel/mma8452.c > > diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig > index e23e5085..1e120fa 100644 > --- a/drivers/iio/accel/Kconfig > +++ b/drivers/iio/accel/Kconfig > @@ -65,4 +65,16 @@ config KXSD9 > Say yes here to build support for the Kionix KXSD9 accelerometer. > Currently this only supports the device via an SPI interface. > > +config MMA8452 > + tristate "Freescale MMA8452Q Accelerometer Driver" > + depends on I2C > + select IIO_BUFFER > + select IIO_TRIGGERED_BUFFER > + help > + Say yes here to build support for the Freescale MMA8452Q 3-axis > + accelerometer. > + > + To compile this driver as a module, choose M here: the module > + will be called mma8452. > + > endmenu > diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile > index c48d15f..dc0e379 100644 > --- a/drivers/iio/accel/Makefile > +++ b/drivers/iio/accel/Makefile > @@ -6,6 +6,7 @@ > obj-$(CONFIG_BMA180) += bma180.o > obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o > obj-$(CONFIG_KXSD9) += kxsd9.o > +obj-$(CONFIG_MMA8452) += mma8452.o > > obj-$(CONFIG_IIO_ST_ACCEL_3AXIS) += st_accel.o > st_accel-y := st_accel_core.o > diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c > new file mode 100644 > index 0000000..17aeea1 > --- /dev/null > +++ b/drivers/iio/accel/mma8452.c > @@ -0,0 +1,439 @@ > +/* > + * mma8452.c - Support for Freescale MMA8452Q 3-axis 12-bit accelerometer > + * > + * Copyright 2014 Peter Meerwald > + * > + * 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. > + * > + * 7-bit I2C slave address 0x1c/0x1d (pin selectable) > + * > + * TODO: interrupt, thresholding, orientation / freefall events, autosleep > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define MMA8452_STATUS 0x00 > +#define MMA8452_OUT_X 0x01 /* MSB first, 12-bit */ > +#define MMA8452_OUT_Y 0x03 > +#define MMA8452_OUT_Z 0x05 > +#define MMA8452_WHO_AM_I 0x0d > +#define MMA8452_DATA_CFG 0x0e > +#define MMA8452_OFF_X 0x2f > +#define MMA8452_OFF_Y 0x30 > +#define MMA8452_OFF_Z 0x31 > +#define MMA8452_CTRL_REG1 0x2a > +#define MMA8452_CTRL_REG2 0x2b > + > +#define MMA8452_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0)) > + > +#define MMA8452_CTRL_DR_MASK (BIT(5) | BIT(4) | BIT(3)) > +#define MMA8452_CTRL_DR_SHIFT 3 > +#define MMA8452_CTRL_DR_DEFAULT 0x4 /* 50 Hz sample frequency */ > +#define MMA8452_CTRL_ACTIVE BIT(0) > + > +#define MMA8452_DATA_CFG_FS_MASK (BIT(1) | BIT(0)) > +#define MMA8452_DATA_CFG_FS_2G 0 > +#define MMA8452_DATA_CFG_FS_4G 1 > +#define MMA8452_DATA_CFG_FS_8G 2 > + > +#define MMA8452_DEVICE_ID 0x2a > + > +struct mma8452_data { > + struct i2c_client *client; > + struct mutex lock; > + u8 ctrl_reg1; > + u8 data_cfg; > +}; > + > +static int mma8452_drdy(struct mma8452_data *data) > +{ > + int tries = 150; > + > + while (tries-- > 0) { > + int ret = i2c_smbus_read_byte_data(data->client, > + MMA8452_STATUS); > + if (ret < 0) > + return ret; > + if ((ret & MMA8452_STATUS_DRDY) == MMA8452_STATUS_DRDY) > + return 0; > + msleep(20); > + } > + > + dev_err(&data->client->dev, "data not ready\n"); > + return -EIO; > +} > + > +static int mma8452_read(struct mma8452_data *data, __be16 buf[3]) > +{ > + int ret = mma8452_drdy(data); > + if (ret < 0) > + return ret; > + return i2c_smbus_read_i2c_block_data(data->client, > + MMA8452_OUT_X, 3 * sizeof(__be16), (u8 *) buf); > +} > + > +static ssize_t mma8452_show_int_plus_micros(char *buf, > + const int (*vals)[2], int n) > +{ > + size_t len = 0; > + > + while (n-- > 0) > + len += scnprintf(buf + len, PAGE_SIZE - len, > + "%d.%06d ", vals[n][0], vals[n][1]); > + > + /* replace trailing space by newline */ > + buf[len - 1] = '\n'; > + > + return len; > +} > + > +static int mma8452_get_int_plus_micros_index(const int (*vals)[2], int n, > + int val, int val2) > +{ > + while (n-- > 0) > + if (val == vals[n][0] && val2 == vals[n][1]) > + return n; > + > + return -EINVAL; > +} > + > +static const int mma8452_samp_freq[8][2] = { > + {800, 0}, {400, 0}, {200, 0}, {100, 0}, {50, 0}, {12, 500000}, > + {6, 250000}, {1, 560000} > +}; > + > +static const int mma8452_scales[3][2] = { > + {0, 977}, {0, 1953}, {0, 3906} > +}; > + > +static ssize_t mma8452_show_samp_freq_avail(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + return mma8452_show_int_plus_micros(buf, mma8452_samp_freq, > + ARRAY_SIZE(mma8452_samp_freq)); > +} > + > +static ssize_t mma8452_show_scale_avail(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + return mma8452_show_int_plus_micros(buf, mma8452_scales, > + ARRAY_SIZE(mma8452_scales)); > +} > + > +static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mma8452_show_samp_freq_avail); > +static IIO_DEVICE_ATTR(in_accel_scale_available, S_IRUGO, > + mma8452_show_scale_avail, NULL, 0); > + > +static int mma8452_get_samp_freq_index(struct mma8452_data *data, > + int val, int val2) > +{ > + return mma8452_get_int_plus_micros_index(mma8452_samp_freq, > + ARRAY_SIZE(mma8452_samp_freq), val, val2); > +} > + > +static int mma8452_get_scale_index(struct mma8452_data *data, > + int val, int val2) > +{ > + return mma8452_get_int_plus_micros_index(mma8452_scales, > + ARRAY_SIZE(mma8452_scales), val, val2); > +} > + > +static int mma8452_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + struct mma8452_data *data = iio_priv(indio_dev); > + __be16 buffer[3]; > + int i, ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + if (iio_buffer_enabled(indio_dev)) > + return -EBUSY; > + > + mutex_lock(&data->lock); > + ret = mma8452_read(data, buffer); > + mutex_unlock(&data->lock); > + if (ret < 0) > + return ret; > + *val = sign_extend32( > + be16_to_cpu(buffer[chan->scan_index]) >> 4, 11); > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + i = data->data_cfg & MMA8452_DATA_CFG_FS_MASK; > + *val = mma8452_scales[i][0]; > + *val2 = mma8452_scales[i][1]; > + return IIO_VAL_INT_PLUS_MICRO; > + case IIO_CHAN_INFO_SAMP_FREQ: > + i = (data->ctrl_reg1 & MMA8452_CTRL_DR_MASK) >> > + MMA8452_CTRL_DR_SHIFT; > + *val = mma8452_samp_freq[i][0]; > + *val2 = mma8452_samp_freq[i][1]; > + return IIO_VAL_INT_PLUS_MICRO; > + case IIO_CHAN_INFO_CALIBBIAS: > + ret = i2c_smbus_read_byte_data(data->client, MMA8452_OFF_X + > + chan->scan_index); > + if (ret < 0) > + return ret; > + *val = sign_extend32(ret, 7); > + return IIO_VAL_INT; > + } > + return -EINVAL; > +} > + > +static int mma8452_standby(struct mma8452_data *data) > +{ > + return i2c_smbus_write_byte_data(data->client, MMA8452_CTRL_REG1, > + data->ctrl_reg1 & ~MMA8452_CTRL_ACTIVE); > +} > + > +static int mma8452_active(struct mma8452_data *data) > +{ > + return i2c_smbus_write_byte_data(data->client, MMA8452_CTRL_REG1, > + data->ctrl_reg1); > +} > + > +static int mma8452_change_config(struct mma8452_data *data, u8 reg, u8 val) > +{ > + int ret; > + > + mutex_lock(&data->lock); > + > + /* config can only be changed when in standby */ > + ret = mma8452_standby(data); > + if (ret < 0) > + goto fail; > + > + ret = i2c_smbus_write_byte_data(data->client, reg, val); > + if (ret < 0) > + goto fail; > + > + ret = mma8452_active(data); > + if (ret < 0) > + goto fail; > + > + ret = 0; > +fail: > + mutex_unlock(&data->lock); > + return ret; > +} > + > +static int mma8452_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, int val2, long mask) > +{ > + struct mma8452_data *data = iio_priv(indio_dev); > + int i; > + > + if (iio_buffer_enabled(indio_dev)) > + return -EBUSY; > + > + switch (mask) { > + case IIO_CHAN_INFO_SAMP_FREQ: > + i = mma8452_get_samp_freq_index(data, val, val2); > + if (i < 0) > + return -EINVAL; > + > + data->ctrl_reg1 &= ~MMA8452_CTRL_DR_MASK; > + data->ctrl_reg1 |= i << MMA8452_CTRL_DR_SHIFT; > + return mma8452_change_config(data, MMA8452_CTRL_REG1, > + data->ctrl_reg1); > + case IIO_CHAN_INFO_SCALE: > + i = mma8452_get_scale_index(data, val, val2); > + if (i < 0) > + return -EINVAL; > + data->data_cfg &= ~MMA8452_DATA_CFG_FS_MASK; > + data->data_cfg |= i; > + return mma8452_change_config(data, MMA8452_DATA_CFG, > + data->data_cfg); > + case IIO_CHAN_INFO_CALIBBIAS: > + if (val < -128 || val > 127) > + return -EINVAL; > + return mma8452_change_config(data, MMA8452_OFF_X + > + chan->scan_index, val); > + default: > + return -EINVAL; > + } > +} > + > +static irqreturn_t mma8452_trigger_handler(int irq, void *p) > +{ > + struct iio_poll_func *pf = p; > + struct iio_dev *indio_dev = pf->indio_dev; > + struct mma8452_data *data = iio_priv(indio_dev); > + u8 buffer[16]; /* 3 16-bit channels + padding + ts */ > + int ret; > + > + ret = mma8452_read(data, (__be16 *) buffer); > + if (ret < 0) > + goto done; > + > + iio_push_to_buffers_with_timestamp(indio_dev, buffer, > + iio_get_time_ns()); > + > +done: > + iio_trigger_notify_done(indio_dev->trig); > + return IRQ_HANDLED; > +} > + > +#define MMA8452_CHANNEL(axis, idx) { \ > + .type = IIO_ACCEL, \ > + .modified = 1, \ > + .channel2 = IIO_MOD_##axis, \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ > + BIT(IIO_CHAN_INFO_CALIBBIAS), \ > + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \ > + BIT(IIO_CHAN_INFO_SCALE), \ > + .scan_index = idx, \ > + .scan_type = { \ > + .sign = 's', \ > + .realbits = 12, \ > + .storagebits = 16, \ > + .shift = 4, \ > + .endianness = IIO_BE, \ > + }, \ > +} > + > +static const struct iio_chan_spec mma8452_channels[] = { > + MMA8452_CHANNEL(X, 0), > + MMA8452_CHANNEL(Y, 1), > + MMA8452_CHANNEL(Z, 2), > + IIO_CHAN_SOFT_TIMESTAMP(3), > +}; > + > +static struct attribute *mma8452_attributes[] = { > + &iio_dev_attr_sampling_frequency_available.dev_attr.attr, > + &iio_dev_attr_in_accel_scale_available.dev_attr.attr, > + NULL > +}; > + > +static const struct attribute_group mma8452_group = { > + .attrs = mma8452_attributes, > +}; > + > +static const struct iio_info mma8452_info = { > + .attrs = &mma8452_group, > + .read_raw = &mma8452_read_raw, > + .write_raw = &mma8452_write_raw, > + .driver_module = THIS_MODULE, > +}; > + > +static const unsigned long mma8452_scan_masks[] = {0x7, 0}; > + > +static int mma8452_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct mma8452_data *data; > + struct iio_dev *indio_dev; > + int ret; > + > + ret = i2c_smbus_read_byte_data(client, MMA8452_WHO_AM_I); > + if (ret < 0) > + return ret; > + if (ret != MMA8452_DEVICE_ID) > + return -ENODEV; > + > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > + if (!indio_dev) > + return -ENOMEM; > + > + data = iio_priv(indio_dev); > + data->client = client; > + mutex_init(&data->lock); > + > + i2c_set_clientdata(client, indio_dev); > + indio_dev->info = &mma8452_info; > + indio_dev->name = id->name; > + indio_dev->dev.parent = &client->dev; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = mma8452_channels; > + indio_dev->num_channels = ARRAY_SIZE(mma8452_channels); > + indio_dev->available_scan_masks = mma8452_scan_masks; > + > + data->ctrl_reg1 = MMA8452_CTRL_ACTIVE | > + (MMA8452_CTRL_DR_DEFAULT << MMA8452_CTRL_DR_SHIFT); > + ret = i2c_smbus_write_byte_data(client, MMA8452_CTRL_REG1, > + data->ctrl_reg1); > + if (ret < 0) > + return ret; > + > + data->data_cfg = MMA8452_DATA_CFG_FS_2G; > + ret = i2c_smbus_write_byte_data(client, MMA8452_DATA_CFG, > + data->data_cfg); > + if (ret < 0) > + return ret; > + > + ret = iio_triggered_buffer_setup(indio_dev, NULL, > + mma8452_trigger_handler, NULL); > + if (ret < 0) > + return ret; > + > + ret = iio_device_register(indio_dev); > + if (ret < 0) > + goto buffer_cleanup; > + return 0; > + > +buffer_cleanup: > + iio_triggered_buffer_cleanup(indio_dev); > + return ret; > +} > + > +static int mma8452_remove(struct i2c_client *client) > +{ > + struct iio_dev *indio_dev = i2c_get_clientdata(client); > + > + iio_device_unregister(indio_dev); > + iio_triggered_buffer_cleanup(indio_dev); > + mma8452_standby(iio_priv(indio_dev)); > + > + return 0; > +} > + > +#ifdef CONFIG_PM_SLEEP > +static int mma8452_suspend(struct device *dev) > +{ > + return mma8452_standby(iio_priv(i2c_get_clientdata( > + to_i2c_client(dev)))); > +} > + > +static int mma8452_resume(struct device *dev) > +{ > + return mma8452_active(iio_priv(i2c_get_clientdata( > + to_i2c_client(dev)))); > +} > + > +static SIMPLE_DEV_PM_OPS(mma8452_pm_ops, mma8452_suspend, mma8452_resume); > +#define MMA8452_PM_OPS (&mma8452_pm_ops) > +#else > +#define MMA8452_PM_OPS NULL > +#endif > + > +static const struct i2c_device_id mma8452_id[] = { > + { "mma8452", 0 }, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, mma8452_id); > + > +static struct i2c_driver mma8452_driver = { > + .driver = { > + .name = "mma8452", > + .pm = MMA8452_PM_OPS, > + }, > + .probe = mma8452_probe, > + .remove = mma8452_remove, > + .id_table = mma8452_id, > +}; > +module_i2c_driver(mma8452_driver); > + > +MODULE_AUTHOR("Peter Meerwald "); > +MODULE_DESCRIPTION("Freescale MMA8452 accelerometer driver"); > +MODULE_LICENSE("GPL"); >