Re: [PATCH v2 2/2] staging: iio: vcnl4000: Replace i2c api's with regmap
From: Jonathan Cameron
Date: Sun Aug 21 2016 - 11:22:03 EST
On 25/07/16 11:57, Pratik Prajapati wrote:
> Signed-off-by: Pratik Prajapati <pratik.prajapati12@xxxxxxxxx>
Why? I.e. Why replace it with regmap. I kind of assumed this was
to add spi support on a dual bus chip, but it doesn't look like
vcnl4000 has an spi version...
I wouldn't have minded if the driver had originally been written
to use regmap, but it seems a fair bit of churn if there are no
advantages.
Caching?
Anyhow, description should include the answer to 'Why?'
Jonathan
> ---
> Changes v1 -> v2
> - added error msgs for led current's read and write functions
>
> drivers/iio/light/vcnl4000.c | 99 ++++++++++++++++++++++++++++++++++++++------
> 1 file changed, 86 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
> index dcf7a6f..9a79022 100644
> --- a/drivers/iio/light/vcnl4000.c
> +++ b/drivers/iio/light/vcnl4000.c
> @@ -21,6 +21,7 @@
> #include <linux/i2c.h>
> #include <linux/err.h>
> #include <linux/delay.h>
> +#include <linux/regmap.h>
>
> #include <linux/iio/iio.h>
> #include <linux/iio/sysfs.h>
> @@ -53,6 +54,7 @@
> struct vcnl4000_data {
> struct i2c_client *client;
> struct mutex lock;
> + struct regmap *regmap;
> };
>
> static const struct i2c_device_id vcnl4000_id[] = {
> @@ -67,20 +69,20 @@ static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
> int tries = 20;
> __be16 buf;
> int ret;
> + unsigned int regval;
>
> mutex_lock(&data->lock);
>
> - ret = i2c_smbus_write_byte_data(data->client, VCNL4000_COMMAND,
> - req_mask);
> + ret = regmap_write(data->regmap, VCNL4000_COMMAND, req_mask);
> if (ret < 0)
> goto fail;
>
> /* wait for data to become ready */
> while (tries--) {
> - ret = i2c_smbus_read_byte_data(data->client, VCNL4000_COMMAND);
> + ret = regmap_read(data->regmap, VCNL4000_COMMAND, ®val);
> if (ret < 0)
> goto fail;
> - if (ret & rdy_mask)
> + if (regval & rdy_mask)
> break;
> msleep(20); /* measurement takes up to 100 ms */
> }
> @@ -92,8 +94,8 @@ static int vcnl4000_measure(struct vcnl4000_data *data, u8 req_mask,
> goto fail;
> }
>
> - ret = i2c_smbus_read_i2c_block_data(data->client,
> - data_reg, sizeof(buf), (u8 *) &buf);
> + ret = regmap_bulk_read(data->regmap, data_reg, (u8 *) &buf,
> + sizeof(buf));
> if (ret < 0)
> goto fail;
>
> @@ -127,29 +129,38 @@ static const struct iio_chan_spec vcnl4000_channels[] = {
>
> static int vcnl4000_write_led_current_raw(struct vcnl4000_data *data, int val)
> {
> + struct device *dev = regmap_get_device(data->regmap);
> int ret;
>
> if (val < 0 || val > VCNL4000_LED_CURRENT_MAX)
> return -ERANGE;
> +
> mutex_lock(&data->lock);
> - ret = i2c_smbus_write_byte_data(data->client, VCNL4000_LED_CURRENT,
> - VCNL4000_LED_CURRENT_MASK & val);
> + ret = regmap_write_bits(data->regmap, VCNL4000_LED_CURRENT,
> + VCNL4000_LED_CURRENT_MASK, val);
> mutex_unlock(&data->lock);
> + if (ret < 0)
> + dev_err(dev, "Failed to write to LED current register: %d",
> + ret);
>
> return ret;
> }
>
> static int vcnl4000_read_led_current_raw(struct vcnl4000_data *data)
> {
> + struct device *dev = regmap_get_device(data->regmap);
> + unsigned int regval;
> int ret;
>
> mutex_lock(&data->lock);
> - ret = i2c_smbus_read_byte_data(data->client, VCNL4000_LED_CURRENT);
> + ret = regmap_read(data->regmap, VCNL4000_LED_CURRENT, ®val);
> mutex_unlock(&data->lock);
> - if (ret < 0)
> + if (ret < 0) {
> + dev_err(dev, "Failed to read LED current register: %d", ret);
> return ret;
> + }
>
> - return ret &= VCNL4000_LED_CURRENT_MASK;
> + return regval &= VCNL4000_LED_CURRENT_MASK;
> }
>
> static int vcnl4000_read_raw(struct iio_dev *indio_dev,
> @@ -223,27 +234,89 @@ static const struct iio_info vcnl4000_info = {
> .driver_module = THIS_MODULE,
> };
>
> +static bool vcnl4000_readable_reg(struct device *dev, unsigned int reg)
> +{
> + switch (reg) {
> + case VCNL4000_COMMAND:
> + case VCNL4000_PROD_REV:
> + case VCNL4000_LED_CURRENT:
> + case VCNL4000_AL_PARAM:
> + case VCNL4000_AL_RESULT_HI:
> + case VCNL4000_AL_RESULT_LO:
> + case VCNL4000_PS_RESULT_HI:
> + case VCNL4000_PS_RESULT_LO:
> + case VCNL4000_PS_MEAS_FREQ:
> + case VCNL4000_PS_MOD_ADJ:
> + return true;
> + default:
> + return false;
> + }
> +}
> +
> +static bool vcnl4000_writeable_reg(struct device *dev, unsigned int reg)
> +{
> + switch (reg) {
> + case VCNL4000_COMMAND:
> + case VCNL4000_LED_CURRENT:
> + case VCNL4000_AL_PARAM:
> + case VCNL4000_PS_MEAS_FREQ:
> + case VCNL4000_PS_MOD_ADJ:
> + return true;
> + default:
> + return false;
> + }
> +}
> +
> +static bool vcnl4000_volatile_reg(struct device *dev, unsigned int reg)
> +{
> + switch (reg) {
> + case VCNL4000_COMMAND:
> + case VCNL4000_AL_RESULT_HI:
> + case VCNL4000_AL_RESULT_LO:
> + case VCNL4000_PS_RESULT_HI:
> + case VCNL4000_PS_RESULT_LO:
> + return true;
> + default:
> + return false;
> + }
> +}
> +
> +static const struct regmap_config vcnl4000_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .max_register = VCNL4000_PS_MOD_ADJ,
> + .readable_reg = vcnl4000_readable_reg,
> + .writeable_reg = vcnl4000_writeable_reg,
> + .volatile_reg = vcnl4000_volatile_reg,
> +};
> +
> static int vcnl4000_probe(struct i2c_client *client,
> const struct i2c_device_id *id)
> {
> struct vcnl4000_data *data;
> struct iio_dev *indio_dev;
> int ret, prod_id;
> + unsigned int regval;
>
> indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> if (!indio_dev)
> return -ENOMEM;
>
> data = iio_priv(indio_dev);
> + data->regmap = devm_regmap_init_i2c(client, &vcnl4000_regmap_config);
> + if (IS_ERR(data->regmap)) {
> + dev_err(&client->dev, "regmap_init failed!\n");
> + return PTR_ERR(data->regmap);
> + }
> i2c_set_clientdata(client, indio_dev);
> data->client = client;
> mutex_init(&data->lock);
>
> - ret = i2c_smbus_read_byte_data(data->client, VCNL4000_PROD_REV);
> + ret = regmap_read(data->regmap, VCNL4000_PROD_REV, ®val);
> if (ret < 0)
> return ret;
>
> - prod_id = ret >> 4;
> + prod_id = regval >> 4;
> if (prod_id != VCNL4010_ID && prod_id != VCNL4000_ID)
> return -ENODEV;
>
>