Re: [PATCH 1/5] staging:iio:hmc5843: Added regmap support

Jonathan Cameron
2014-07-07T16:58:20Z

On 02/07/14 14:50, Josef Gajdusek wrote:
> This patch changes hmc5843.c to use regmap. This provides transparent caching
> to the code as well as abstraction necessary to add support for SPI-based
> hmc5983.
>
> Signed-off-by: Josef Gajdusek <atx@atx.name>
Hi Josef,

A few little bits and pieces inline.
Peter, could you also take a look at this series?

Thanks,

Jonathan
> ---
> drivers/staging/iio/magnetometer/Kconfig | 1 +
> drivers/staging/iio/magnetometer/hmc5843.c | 145 +++++++++++++++++++----------
> 2 files changed, 98 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/staging/iio/magnetometer/Kconfig b/drivers/staging/iio/magnetometer/Kconfig
> index 34634da..ad88d61 100644
> --- a/drivers/staging/iio/magnetometer/Kconfig
> +++ b/drivers/staging/iio/magnetometer/Kconfig
> @@ -8,6 +8,7 @@ config SENSORS_HMC5843
> depends on I2C
> select IIO_BUFFER
> select IIO_TRIGGERED_BUFFER
> + select REGMAP_I2C
> help
> Say Y here to add support for the Honeywell HMC5843, HMC5883 and
> HMC5883L 3-Axis Magnetometer (digital compass).
> diff --git a/drivers/staging/iio/magnetometer/hmc5843.c b/drivers/staging/iio/magnetometer/hmc5843.c
> index d4f4dd9..cc12308 100644
> --- a/drivers/staging/iio/magnetometer/hmc5843.c
> +++ b/drivers/staging/iio/magnetometer/hmc5843.c
> @@ -21,6 +21,7 @@
>
> #include <linux/module.h>
> #include <linux/i2c.h>
> +#include <linux/regmap.h>
> #include <linux/iio/iio.h>
> #include <linux/iio/sysfs.h>
> #include <linux/iio/trigger_consumer.h>
> @@ -34,6 +35,7 @@
> #define HMC5843_DATA_OUT_MSB_REGS 0x03
> #define HMC5843_STATUS_REG 0x09
> #define HMC5843_ID_REG 0x0a
> +#define HMC5843_ID_END 0x0c
>
> enum hmc5843_ids {
> HMC5843_ID,
> @@ -49,6 +51,7 @@ enum hmc5843_ids {
> #define HMC5843_RANGE_GAIN_OFFSET 0x05
> #define HMC5843_RANGE_GAIN_DEFAULT 0x01
> #define HMC5843_RANGE_GAINS 8
> +#define HMC5843_RANGE_GAIN_MASK 0xe0
>
> /* Device status */
> #define HMC5843_DATA_READY 0x01
> @@ -68,6 +71,7 @@ enum hmc5843_ids {
> #define HMC5843_RATE_OFFSET 0x02
> #define HMC5843_RATE_DEFAULT 0x04
> #define HMC5843_RATES 7
> +#define HMC5843_RATE_MASK 0x1c
>
> /* Device measurement configuration */
> #define HMC5843_MEAS_CONF_NORMAL 0x00
> @@ -121,10 +125,7 @@ struct hmc5843_chip_info {
> struct hmc5843_data {
> struct i2c_client *client;
> struct mutex lock;
> - u8 rate;
> - u8 meas_conf;
> - u8 operating_mode;
> - u8 range;
> + struct regmap *regmap;
> const struct hmc5843_chip_info *variant;
> __be16 buffer[8]; /* 3x 16-bit channels + padding + 64-bit timestamp */
> };
> @@ -135,10 +136,8 @@ static s32 hmc5843_set_mode(struct hmc5843_data *data, u8 operating_mode)
> int ret;
>
> mutex_lock(&data->lock);
> - ret = i2c_smbus_write_byte_data(data->client, HMC5843_MODE_REG,
> - operating_mode & HMC5843_MODE_MASK);
> - if (ret >= 0)
> - data->operating_mode = operating_mode;
> + ret = regmap_update_bits(data->regmap, HMC5843_MODE_REG,
> + HMC5843_MODE_MASK, operating_mode);
Whilst minor, we do have a slight change in how this works in the event
of an error. I don't particularly mind it, but perhaps should have
been broken out for separate discussion.

> mutex_unlock(&data->lock);
>
> return ret;
> @@ -146,15 +145,15 @@ static s32 hmc5843_set_mode(struct hmc5843_data *data, u8 operating_mode)
>
> static int hmc5843_wait_measurement(struct hmc5843_data *data)
> {
> - s32 result;
> int tries = 150;
> + int val;
> + int ret;
>
> while (tries-- > 0) {
> - result = i2c_smbus_read_byte_data(data->client,
> - HMC5843_STATUS_REG);
> - if (result < 0)
> - return result;
> - if (result & HMC5843_DATA_READY)
> + ret = regmap_read(data->regmap, HMC5843_STATUS_REG, &val);
> + if (ret < 0)
> + return ret;
> + if (val & HMC5843_DATA_READY)
> break;
> msleep(20);
> }
> @@ -171,20 +170,20 @@ static int hmc5843_wait_measurement(struct hmc5843_data *data)
> static int hmc5843_read_measurement(struct hmc5843_data *data,
> int idx, int *val)
> {
> - s32 result;
> __be16 values[3];
> + int ret;
>
> mutex_lock(&data->lock);
> - result = hmc5843_wait_measurement(data);
> - if (result < 0) {
> + ret = hmc5843_wait_measurement(data);
> + if (ret < 0) {
> mutex_unlock(&data->lock);
> - return result;
> + return ret;
> }
> - result = i2c_smbus_read_i2c_block_data(data->client,
> - HMC5843_DATA_OUT_MSB_REGS, sizeof(values), (u8 *) values);
> + ret = regmap_bulk_read(data->regmap, HMC5843_DATA_OUT_MSB_REGS,
> + values, sizeof(values));
> mutex_unlock(&data->lock);
> - if (result < 0)
> - return -EINVAL;
> + if (ret < 0)
> + return ret;
>
> *val = sign_extend32(be16_to_cpu(values[idx]), 15);
> return IIO_VAL_INT;
> @@ -208,16 +207,13 @@ static int hmc5843_read_measurement(struct hmc5843_data *data,
> * and BN.
> *
> */
> -static s32 hmc5843_set_meas_conf(struct hmc5843_data *data, u8 meas_conf)
> +static int hmc5843_set_meas_conf(struct hmc5843_data *data, u8 meas_conf)
> {
> int ret;
>
> mutex_lock(&data->lock);
> - ret = i2c_smbus_write_byte_data(data->client, HMC5843_CONFIG_REG_A,
> - (meas_conf & HMC5843_MEAS_CONF_MASK) |
> - (data->rate << HMC5843_RATE_OFFSET));
> - if (ret >= 0)
> - data->meas_conf = meas_conf;
> + ret = regmap_update_bits(data->regmap, HMC5843_CONFIG_REG_A,
> + HMC5843_MEAS_CONF_MASK, meas_conf);
> mutex_unlock(&data->lock);
>
> return ret;
> @@ -228,7 +224,15 @@ static ssize_t hmc5843_show_measurement_configuration(struct device *dev,
> char *buf)
> {
> struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev));
> - return sprintf(buf, "%d\n", data->meas_conf);
> + int val;
> + int ret;
> +
> + ret = regmap_read(data->regmap, HMC5843_CONFIG_REG_A, &val);
> + if (ret)
> + return ret;
> + val &= HMC5843_MEAS_CONF_MASK;
> +
> + return sprintf(buf, "%d\n", val);
> }
>
> static ssize_t hmc5843_set_measurement_configuration(struct device *dev,
> @@ -282,10 +286,8 @@ static int hmc5843_set_samp_freq(struct hmc5843_data *data, u8 rate)
> int ret;
>
> mutex_lock(&data->lock);
> - ret = i2c_smbus_write_byte_data(data->client, HMC5843_CONFIG_REG_A,
> - data->meas_conf | (rate << HMC5843_RATE_OFFSET));
> - if (ret >= 0)
> - data->rate = rate;
> + ret = regmap_update_bits(data->regmap, HMC5843_CONFIG_REG_A,
> + HMC5843_RATE_MASK, rate << HMC5843_RATE_OFFSET);
> mutex_unlock(&data->lock);
>
> return ret;
> @@ -309,10 +311,9 @@ static int hmc5843_set_range_gain(struct hmc5843_data *data, u8 range)
> int ret;
>
> mutex_lock(&data->lock);
> - ret = i2c_smbus_write_byte_data(data->client, HMC5843_CONFIG_REG_B,
> - range << HMC5843_RANGE_GAIN_OFFSET);
> - if (ret >= 0)
> - data->range = range;
> + ret = regmap_update_bits(data->regmap, HMC5843_CONFIG_REG_B,
> + HMC5843_RANGE_GAIN_MASK,
> + range << HMC5843_RANGE_GAIN_OFFSET);
> mutex_unlock(&data->lock);
>
> return ret;
> @@ -358,17 +359,26 @@ static int hmc5843_read_raw(struct iio_dev *indio_dev,
> int *val, int *val2, long mask)
> {
> struct hmc5843_data *data = iio_priv(indio_dev);
> + int rval;
> + int ret;
>
> switch (mask) {
> case IIO_CHAN_INFO_RAW:
> return hmc5843_read_measurement(data, chan->scan_index, val);
> case IIO_CHAN_INFO_SCALE:
> + ret = regmap_read(data->regmap, HMC5843_CONFIG_REG_B, &rval);
> + if (ret < 0)
> + return ret;
> *val = 0;
> - *val2 = data->variant->regval_to_nanoscale[data->range];
> + *val2 = data->variant->regval_to_nanoscale[rval >> HMC5843_RANGE_GAIN_OFFSET];
> return IIO_VAL_INT_PLUS_NANO;
> case IIO_CHAN_INFO_SAMP_FREQ:
> - *val = data->variant->regval_to_samp_freq[data->rate][0];
> - *val2 = data->variant->regval_to_samp_freq[data->rate][1];
> + ret = regmap_read(data->regmap, HMC5843_CONFIG_REG_A, &rval);
> + if (ret < 0)
> + return ret;
> + rval &= HMC5843_RATE_MASK;
> + *val = data->variant->regval_to_samp_freq[rval][0];
> + *val2 = data->variant->regval_to_samp_freq[rval][1];
> return IIO_VAL_INT_PLUS_MICRO;
> }
> return -EINVAL;
> @@ -426,9 +436,9 @@ static irqreturn_t hmc5843_trigger_handler(int irq, void *p)
> goto done;
> }
>
> - ret = i2c_smbus_read_i2c_block_data(data->client,
> - HMC5843_DATA_OUT_MSB_REGS, 3 * sizeof(__be16),
> - (u8 *) data->buffer);
> + ret = regmap_bulk_read(data->regmap, HMC5843_DATA_OUT_MSB_REGS,
> + data->buffer, 3 * sizeof(__be16));
> +
> mutex_unlock(&data->lock);
> if (ret < 0)
> goto done;
> @@ -508,8 +518,8 @@ static int hmc5843_init(struct hmc5843_data *data)
> int ret;
> u8 id[3];
>
> - ret = i2c_smbus_read_i2c_block_data(data->client, HMC5843_ID_REG,
> - sizeof(id), id);
> + ret = regmap_bulk_read(data->regmap, HMC5843_ID_REG,
> + id, ARRAY_SIZE(id));
> if (ret < 0)
> return ret;
> if (id[0] != 'H' || id[1] != '4' || id[2] != '3') {
> @@ -539,6 +549,44 @@ static const struct iio_info hmc5843_info = {
>
> static const unsigned long hmc5843_scan_masks[] = {0x7, 0};
>
> +static const struct regmap_range hmc5843_readable_ranges[] = {
> + regmap_reg_range(0, HMC5843_ID_END),
> +};
> +
> +static struct regmap_access_table hmc5843_readable_table = {
> + .yes_ranges = hmc5843_readable_ranges,
> + .n_yes_ranges = ARRAY_SIZE(hmc5843_readable_ranges),
> +};
> +
> +static const struct regmap_range hmc5843_writable_ranges[] = {
> + regmap_reg_range(0, HMC5843_MODE_REG),
> +};
> +
> +static struct regmap_access_table hmc5843_writable_table = {
> + .yes_ranges = hmc5843_writable_ranges,
> + .n_yes_ranges = ARRAY_SIZE(hmc5843_writable_ranges),
> +};
> +
> +static const struct regmap_range hmc5843_volatile_ranges[] = {
> + regmap_reg_range(HMC5843_DATA_OUT_MSB_REGS, HMC5843_STATUS_REG),
> +};
> +
> +static struct regmap_access_table hmc5843_volatile_table = {
> + .yes_ranges = hmc5843_volatile_ranges,
> + .n_yes_ranges = ARRAY_SIZE(hmc5843_volatile_ranges),
> +};
> +
> +static struct regmap_config hmc5843_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> +
> + .rd_table = &hmc5843_readable_table,
> + .wr_table = &hmc5843_writable_table,
> + .volatile_table = &hmc5843_volatile_table,
> +
> + .cache_type = REGCACHE_RBTREE,
> +};
> +
> static int hmc5843_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> @@ -554,6 +602,7 @@ static int hmc5843_probe(struct i2c_client *client,
> data = iio_priv(indio_dev);
> data->client = client;
> data->variant = &hmc5843_chip_info_tbl[id->driver_data];
> + data->regmap = devm_regmap_init_i2c(client, &hmc5843_regmap_config);
> mutex_init(&data->lock);
>
> i2c_set_clientdata(client, indio_dev);
> @@ -589,12 +638,12 @@ static int hmc5843_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);
> -
> /* sleep mode to save power */
> hmc5843_set_mode(iio_priv(indio_dev), HMC5843_MODE_SLEEP);
>
> + iio_device_unregister(indio_dev);
> + iio_triggered_buffer_cleanup(indio_dev);
Why move these? You now have the device going to sleep whilst
the userspace interface is still available...
> +
> return 0;
> }
>
>