Re: [PATCH v2 5/5] iio: pressure: bmp280: Add nvmem operations for BMP580

Jonathan Cameron
2022-12-30T18:36:18Z

On Mon, 26 Dec 2022 15:29:24 +0100
Angel Iglesias <ang.iglesiasg@gmail.com> wrote:

> The pressure sensor BMP580 contains a non-volatile memory that stores
> trimming and configuration params. That memory provides an programmable
> user range of three 2-byte words.
>
> Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>

Not much in this one from me other than follow on from earlier patch.
Thanks,

Jonathan

>
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index 44901c6eb2f9..578d145be55d 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -28,6 +28,7 @@
> #include <linux/bitfield.h>
> #include <linux/device.h>
> #include <linux/module.h>
> +#include <linux/nvmem-provider.h>
> #include <linux/regmap.h>
> #include <linux/delay.h>
> #include <linux/iio/iio.h>
> @@ -1628,8 +1629,140 @@ static const int bmp580_odr_table[][2] = {
> [BMP580_ODR_0_125HZ] = {0, 125000},
> };
>
> +const int bmp580_nvmem_addrs[] = { 0x20, 0x21, 0x22 };
> +
> +static int bmp580_nvmem_read(void *priv, unsigned int offset, void *val,
> + size_t bytes)
> +{
> + struct bmp280_data *data = priv;
> + u16 *dst = val;
> + int ret, addr;
> +
> + pm_runtime_get_sync(data->dev);
> + mutex_lock(&data->lock);
> +
> + /* Set sensor in standby mode */
> + ret = regmap_update_bits(data->regmap, BMP580_REG_ODR_CONFIG,
> + BMP580_MODE_MASK | BMP580_ODR_DEEPSLEEP_DIS,
> + BMP580_ODR_DEEPSLEEP_DIS |
> + FIELD_PREP(BMP580_MODE_MASK, BMP580_MODE_SLEEP));
> + if (ret) {
> + dev_err(data->dev, "failed to change sensor to standby mode\n");
> + goto exit;
> + }
> + /* Wait standby transition time */
> + usleep_range(2500, 3000);
> +
> + while (bytes >= sizeof(u16)) {
> + addr = bmp580_nvmem_addrs[offset / sizeof(u16)];
> +
> + ret = regmap_write(data->regmap, BMP580_REG_NVM_ADDR,
> + FIELD_PREP(BMP580_NVM_ROW_ADDR_MASK, addr));
> + if (ret) {
> + dev_err(data->dev, "error writing nvm address\n");
> + goto exit;
> + }
> +
> + ret = bmp580_cmd(data, BMP580_NVM_READ_CMD);
Ah. Here is the command being used. Good to pull that code forwards to this patch.

> + if (ret)
> + goto exit;
> +
> + ret = regmap_bulk_read(data->regmap, BMP580_REG_NVM_DATA_LSB, &data->le16,
> + sizeof(data->le16));
> + if (ret) {
> + dev_err(data->dev, "error reading nvm data regs\n");
> + goto exit;
> + }
> +
> + *dst++ = le16_to_cpu(data->le16);
> + bytes -= sizeof(u16);

sizeof(le16) seems more appropriate (obviously it's the same value).

> + offset += sizeof(u16);
> + }
> +exit:
> + /* Restore chip config */
> + data->chip_info->chip_config(data);
> + mutex_unlock(&data->lock);
> + pm_runtime_mark_last_busy(data->dev);
> + pm_runtime_put_autosuspend(data->dev);
> + return ret;
> +}
> +
> +static int bmp580_nvmem_write(void *priv, unsigned int offset, void *val,
> + size_t bytes)
> +{
> + struct bmp280_data *data = priv;
> + u16 *buf = val;
> + int ret, addr;
> +
> + pm_runtime_get_sync(data->dev);
> + mutex_lock(&data->lock);
> +
> + /* Set sensor in standby mode */
> + ret = regmap_update_bits(data->regmap, BMP580_REG_ODR_CONFIG,
> + BMP580_MODE_MASK | BMP580_ODR_DEEPSLEEP_DIS,
> + BMP580_ODR_DEEPSLEEP_DIS |
> + FIELD_PREP(BMP580_MODE_MASK, BMP580_MODE_SLEEP));
> + if (ret) {
> + dev_err(data->dev, "failed to change sensor to standby mode\n");
> + goto exit;
> + }
> + /* Wait standby transition time */
> + usleep_range(2500, 3000);
> +
> + while (bytes >= sizeof(u16)) {
> + addr = bmp580_nvmem_addrs[offset / sizeof(u16)];
> +
> + ret = regmap_write(data->regmap, BMP580_REG_NVM_ADDR, BMP580_NVM_PROG_EN |
> + FIELD_PREP(BMP580_NVM_ROW_ADDR_MASK, addr));
> + if (ret) {
> + dev_err(data->dev, "error writing nvm address\n");
> + goto exit;
> + }
> + data->le16 = cpu_to_le16(*buf++);
> +
> + ret = regmap_bulk_write(data->regmap, BMP580_REG_NVM_DATA_LSB, &data->le16,
> + sizeof(data->le16));
> + if (ret) {
> + dev_err(data->dev, "error writing LSB NVM data regs\n");
> + goto exit;
> + }
> +
> + ret = bmp580_cmd(data, BMP580_NVM_WRITE_CMD);
> + if (ret)
> + goto exit;
> +
> + /* Disable programming mode bit */
> + ret = regmap_update_bits(data->regmap, BMP580_REG_NVM_ADDR,
> + BMP580_NVM_PROG_EN, 0);
> + if (ret) {
> + dev_err(data->dev, "error resetting nvm write\n");
> + goto exit;
> + }
> +
> + bytes -= sizeof(u16);

As above, maybe sizeof(le16)

> + offset += sizeof(u16);
> + }
> +exit:
> + /* Restore chip config */
> + data->chip_info->chip_config(data);
> + mutex_unlock(&data->lock);
> + pm_runtime_mark_last_busy(data->dev);
> + pm_runtime_put_autosuspend(data->dev);
> + return ret;
> +}
> +