From 694e1b5f95725d48a1d4ff5e93042118d50ee235 Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Fri, 12 Aug 2011 17:48:03 +0100 Subject: [PATCH] staging:iio:magnetometer:ak8975 convert to iio_chan_spec + cleanups. iio_chan_spec conversion is straight forward. Other changes: * use i2c_smbus_write_byte_data in write_data * c99 isms to setup various structures. * move the comment about the scale factor and kill off trivial access func. * make mode setting code use a bool rather than a ulong. Ultimately I'd like to get rid of that mode bit entirely and handle it through core pm routines, but have left it for now. Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/staging/iio/magnetometer/ak8975.c | 214 ++++++++++++++---------------- 1 file changed, 103 insertions(+), 111 deletions(-) diff --git a/drivers/staging/iio/magnetometer/ak8975.c b/drivers/staging/iio/magnetometer/ak8975.c index 33919e8..a17fa9f 100644 --- a/drivers/staging/iio/magnetometer/ak8975.c +++ b/drivers/staging/iio/magnetometer/ak8975.c @@ -31,7 +31,6 @@ #include #include "../iio.h" -#include "magnet.h" /* * Register definitions, as well as various shifts and masks to get at the @@ -93,38 +92,28 @@ struct ak8975_data { struct mutex lock; u8 asa[3]; long raw_to_gauss[3]; - unsigned long mode; + bool mode; u8 reg_cache[AK8975_MAX_REGS]; int eoc_gpio; int eoc_irq; }; +static const int ak8975_index_to_reg[] = { + AK8975_REG_HXL, AK8975_REG_HYL, AK8975_REG_HZL, +}; + /* * Helper function to write to the I2C device's registers. */ static int ak8975_write_data(struct i2c_client *client, u8 reg, u8 val, u8 mask, u8 shift) { - u8 regval; - struct i2c_msg msg; - u8 w_data[2]; - int ret = 0; - struct ak8975_data *data = i2c_get_clientdata(client); + u8 regval; + int ret; - regval = data->reg_cache[reg]; - regval &= ~mask; - regval |= val << shift; - - w_data[0] = reg; - w_data[1] = regval; - - msg.addr = client->addr; - msg.flags = 0; - msg.len = 2; - msg.buf = w_data; - - ret = i2c_transfer(client->adapter, &msg, 1); + regval = (data->reg_cache[reg] & ~mask) | (val << shift); + ret = i2c_smbus_write_byte_data(client, reg, regval); if (ret < 0) { dev_err(&client->dev, "Write to device fails status %x\n", ret); return ret; @@ -140,21 +129,20 @@ static int ak8975_write_data(struct i2c_client *client, static int ak8975_read_data(struct i2c_client *client, u8 reg, u8 length, u8 *buffer) { - struct i2c_msg msg[2]; - u8 w_data[2]; int ret; - - w_data[0] = reg; - - msg[0].addr = client->addr; - msg[0].flags = I2C_M_NOSTART; /* set repeated start and write */ - msg[0].len = 1; - msg[0].buf = w_data; - - msg[1].addr = client->addr; - msg[1].flags = I2C_M_RD; - msg[1].len = length; - msg[1].buf = buffer; + struct i2c_msg msg[2] = { + { + .addr = client->addr, + .flags = I2C_M_NOSTART, + .len = 1, + .buf = ®, + }, { + .addr = client->addr, + .flags = I2C_M_RD, + .len = length, + .buf = buffer, + } + }; ret = i2c_transfer(client->adapter, msg, 2); if (ret < 0) { @@ -204,8 +192,41 @@ static int ak8975_setup(struct i2c_client *client) return ret; } - /* Precalculate scale factor for each axis and - store in the device data. */ +/* + * Precalculate scale factor (in Gauss units) for each axis and + * store in the device data. + * + * This scale factor is axis-dependent, and is derived from 3 calibration + * factors ASA(x), ASA(y), and ASA(z). + * + * These ASA values are read from the sensor device at start of day, and + * cached in the device context struct. + * + * Adjusting the flux value with the sensitivity adjustment value should be + * done via the following formula: + * + * Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 ) + * + * where H is the raw value, ASA is the sensitivity adjustment, and Hadj + * is the resultant adjusted value. + * + * We reduce the formula to: + * + * Hadj = H * (ASA + 128) / 256 + * + * H is in the range of -4096 to 4095. The magnetometer has a range of + * +-1229uT. To go from the raw value to uT is: + * + * HuT = H * 1229/4096, or roughly, 3/10. + * + * Since 1uT = 100 gauss, our final scale factor becomes: + * + * Hadj = H * ((ASA + 128) / 256) * 3/10 * 100 + * Hadj = H * ((ASA + 128) * 30 / 256 + * + * Since ASA doesn't change, we cache the resultant scale factor into the + * device context in ak8975_setup(). + */ data->raw_to_gauss[0] = ((data->asa[0] + 128) * 30) >> 8; data->raw_to_gauss[1] = ((data->asa[1] + 128) * 30) >> 8; data->raw_to_gauss[2] = ((data->asa[2] + 128) * 30) >> 8; @@ -222,7 +243,7 @@ static ssize_t show_mode(struct device *dev, struct device_attribute *devattr, struct iio_dev *indio_dev = dev_get_drvdata(dev); struct ak8975_data *data = iio_priv(indio_dev); - return sprintf(buf, "%lu\n", data->mode); + return sprintf(buf, "%u\n", data->mode); } /* @@ -235,26 +256,22 @@ static ssize_t store_mode(struct device *dev, struct device_attribute *devattr, struct iio_dev *indio_dev = dev_get_drvdata(dev); struct ak8975_data *data = iio_priv(indio_dev); struct i2c_client *client = data->client; - unsigned long oval; + bool value; int ret; /* Convert mode string and do some basic sanity checking on it. only 0 or 1 are valid. */ - if (strict_strtoul(buf, 10, &oval)) - return -EINVAL; - - if (oval > 1) { - dev_err(dev, "mode value is not supported\n"); - return -EINVAL; - } + ret = strtobool(buf, &value); + if (ret < 0) + return ret; mutex_lock(&data->lock); /* Write the mode to the device. */ - if (data->mode != oval) { + if (data->mode != value) { ret = ak8975_write_data(client, AK8975_REG_CNTL, - (u8)oval, + (u8)value, AK8975_REG_CNTL_MODE_MASK, AK8975_REG_CNTL_MODE_SHIFT); @@ -263,7 +280,7 @@ static ssize_t store_mode(struct device *dev, struct device_attribute *devattr, mutex_unlock(&data->lock); return ret; } - data->mode = oval; + data->mode = value; } mutex_unlock(&data->lock); @@ -271,50 +288,6 @@ static ssize_t store_mode(struct device *dev, struct device_attribute *devattr, return count; } -/* - * Emits the scale factor to bring the raw value into Gauss units. - * - * This scale factor is axis-dependent, and is derived from 3 calibration - * factors ASA(x), ASA(y), and ASA(z). - * - * These ASA values are read from the sensor device at start of day, and - * cached in the device context struct. - * - * Adjusting the flux value with the sensitivity adjustment value should be - * done via the following formula: - * - * Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 ) - * - * where H is the raw value, ASA is the sensitivity adjustment, and Hadj - * is the resultant adjusted value. - * - * We reduce the formula to: - * - * Hadj = H * (ASA + 128) / 256 - * - * H is in the range of -4096 to 4095. The magnetometer has a range of - * +-1229uT. To go from the raw value to uT is: - * - * HuT = H * 1229/4096, or roughly, 3/10. - * - * Since 1uT = 100 gauss, our final scale factor becomes: - * - * Hadj = H * ((ASA + 128) / 256) * 3/10 * 100 - * Hadj = H * ((ASA + 128) * 30 / 256 - * - * Since ASA doesn't change, we cache the resultant scale factor into the - * device context in ak8975_setup(). - */ -static ssize_t show_scale(struct device *dev, struct device_attribute *devattr, - char *buf) -{ - struct iio_dev *indio_dev = dev_get_drvdata(dev); - struct ak8975_data *data = iio_priv(indio_dev); - struct iio_dev_attr *this_attr = to_iio_dev_attr(devattr); - - return sprintf(buf, "%ld\n", data->raw_to_gauss[this_attr->address]); -} - static int wait_conversion_complete_gpio(struct ak8975_data *data) { struct i2c_client *client = data->client; @@ -371,13 +344,10 @@ static int wait_conversion_complete_polled(struct ak8975_data *data) /* * Emits the raw flux value for the x, y, or z axis. */ -static ssize_t show_raw(struct device *dev, struct device_attribute *devattr, - char *buf) +static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) { - struct iio_dev *indio_dev = dev_get_drvdata(dev); struct ak8975_data *data = iio_priv(indio_dev); struct i2c_client *client = data->client; - struct iio_dev_attr *this_attr = to_iio_dev_attr(devattr); u16 meas_reg; s16 raw; u8 read_status; @@ -429,7 +399,8 @@ static ssize_t show_raw(struct device *dev, struct device_attribute *devattr, /* Read the flux value from the appropriate register (the register is specified in the iio device attributes). */ - ret = ak8975_read_data(client, this_attr->address, 2, (u8 *)&meas_reg); + ret = ak8975_read_data(client, ak8975_index_to_reg[index], + 2, (u8 *)&meas_reg); if (ret < 0) { dev_err(&client->dev, "Read axis data fails\n"); goto exit; @@ -442,30 +413,48 @@ static ssize_t show_raw(struct device *dev, struct device_attribute *devattr, /* Clamp to valid range. */ raw = clamp_t(s16, raw, -4096, 4095); - - return sprintf(buf, "%d\n", raw); + *val = raw; + return IIO_VAL_INT; exit: mutex_unlock(&data->lock); return ret; } +static int ak8975_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, + long mask) +{ + struct ak8975_data *data = iio_priv(indio_dev); + + switch (mask) { + case 0: + return ak8975_read_axis(indio_dev, chan->address, val); + case (1 << IIO_CHAN_INFO_SCALE_SEPARATE): + *val = data->raw_to_gauss[chan->address]; + return IIO_VAL_INT; + } + return -EINVAL; +} + +#define AK8975_CHANNEL(axis, index) \ + { \ + .type = IIO_MAGN, \ + .modified = 1, \ + .channel2 = IIO_MOD_##axis, \ + .info_mask = (1 << IIO_CHAN_INFO_SCALE_SEPARATE), \ + .address = index, \ + } + +static const struct iio_chan_spec ak8975_channels[] = { + AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2), +}; + static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, show_mode, store_mode, 0); -static IIO_DEV_ATTR_MAGN_X_SCALE(S_IRUGO, show_scale, NULL, 0); -static IIO_DEV_ATTR_MAGN_Y_SCALE(S_IRUGO, show_scale, NULL, 1); -static IIO_DEV_ATTR_MAGN_Z_SCALE(S_IRUGO, show_scale, NULL, 2); -static IIO_DEV_ATTR_MAGN_X(show_raw, AK8975_REG_HXL); -static IIO_DEV_ATTR_MAGN_Y(show_raw, AK8975_REG_HYL); -static IIO_DEV_ATTR_MAGN_Z(show_raw, AK8975_REG_HZL); static struct attribute *ak8975_attr[] = { &iio_dev_attr_mode.dev_attr.attr, - &iio_dev_attr_magn_x_scale.dev_attr.attr, - &iio_dev_attr_magn_y_scale.dev_attr.attr, - &iio_dev_attr_magn_z_scale.dev_attr.attr, - &iio_dev_attr_magn_x_raw.dev_attr.attr, - &iio_dev_attr_magn_y_raw.dev_attr.attr, - &iio_dev_attr_magn_z_raw.dev_attr.attr, NULL }; @@ -475,6 +464,7 @@ static struct attribute_group ak8975_attr_group = { static const struct iio_info ak8975_info = { .attrs = &ak8975_attr_group, + .read_raw = &ak8975_read_raw, .driver_module = THIS_MODULE, }; @@ -530,6 +520,8 @@ static int ak8975_probe(struct i2c_client *client, data->eoc_irq = client->irq; data->eoc_gpio = eoc_gpio; indio_dev->dev.parent = &client->dev; + indio_dev->channels = ak8975_channels; + indio_dev->num_channels = ARRAY_SIZE(ak8975_channels); indio_dev->info = &ak8975_info; indio_dev->modes = INDIO_DIRECT_MODE; -- 2.7.4