[RESEND v4 15/15] iio: adc: aspeed: Get and set trimming data.

Jonathan Cameron
2021-08-29T15:45:31Z

On Tue, 24 Aug 2021 17:12:43 +0800
Billy Tsai <billy_tsai@aspeedtech.com> wrote:

> The adc controller have trimming register for fine-tune the reference

Nice to have ADC instead of adc (though not that important as meaning is clear).

> voltage. The trimming value come from the otp register which will be
> written before chip product. This patch will read this otp value and

written during chip production? (perhaps that's what is intended?)

> configure it to the adc register when adc controller probe and using dts
> property "aspeed,trim-data-valid" to determine whether to execute this
> flow.
>
> Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> ---
> drivers/iio/adc/aspeed_adc.c | 68 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 68 insertions(+)
>
> diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
> index 0c5d84e82561..bd7fb23f3510 100644
> --- a/drivers/iio/adc/aspeed_adc.c
> +++ b/drivers/iio/adc/aspeed_adc.c
> @@ -25,6 +25,8 @@
> #include <linux/spinlock.h>
> #include <linux/types.h>
> #include <linux/bitfield.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>
>
> #include <linux/iio/iio.h>
> #include <linux/iio/driver.h>
> @@ -72,6 +74,11 @@
> */
> #define ASPEED_ADC_DEF_SAMPLING_RATE 65000
>
> +struct aspeed_adc_trim_locate {
> + const unsigned int offset;
> + const unsigned int field;
> +};
> +
> struct aspeed_adc_model_data {
> const char *model_name;
> unsigned int min_sampling_rate; // Hz
> @@ -82,6 +89,7 @@ struct aspeed_adc_model_data {
> bool bat_sense_sup;
> u8 scaler_bit_width;
> unsigned int num_channels;
> + const struct aspeed_adc_trim_locate *trim_locate;
> };
>
> struct adc_gain {
> @@ -136,6 +144,44 @@ static const struct iio_chan_spec aspeed_adc_iio_channels[] = {
> ASPEED_CHAN(15, 0x2E),
> };
>
> +static int aspeed_adc_set_trim_data(struct iio_dev *indio_dev)
> +{
> + struct device_node *syscon;
> + struct regmap *scu;
> + u32 scu_otp, trimming_val;
> + struct aspeed_adc_data *data = iio_priv(indio_dev);
> +
> + syscon = of_find_node_by_name(NULL, "syscon");
> + if (syscon == NULL) {
> + dev_warn(data->dev, "Couldn't find syscon node\n");
> + return -EOPNOTSUPP;
> + }
> + scu = syscon_node_to_regmap(syscon);
> + if (IS_ERR(scu)) {
> + dev_warn(data->dev, "Failed to get syscon regmap\n");
> + return -EOPNOTSUPP;
> + }
> + if (data->model_data->trim_locate) {
> + if (regmap_read(scu, data->model_data->trim_locate->offset,
> + &scu_otp)) {
> + dev_warn(data->dev,
> + "Failed to get adc trimming data\n");
> + trimming_val = 0x8;
> + } else {
> + trimming_val =
> + ((scu_otp) &
> + (data->model_data->trim_locate->field)) >>
> + __ffs(data->model_data->trim_locate->field);
> + }
> + dev_dbg(data->dev,
> + "trimming val = %d, offset = %08x, fields = %08x\n",
> + trimming_val, data->model_data->trim_locate->offset,
> + data->model_data->trim_locate->field);
> + writel(trimming_val, data->base + ASPEED_REG_COMPENSATION_TRIM);
> + }
> + return 0;
> +}
> +
> static int aspeed_adc_compensation(struct iio_dev *indio_dev)
> {
> struct aspeed_adc_data *data = iio_priv(indio_dev);
> @@ -506,6 +552,10 @@ static int aspeed_adc_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> + if (of_find_property(data->dev->of_node, "aspeed,trim-data-valid",
> + NULL))
> + aspeed_adc_set_trim_data(indio_dev);
> +
> if (of_find_property(data->dev->of_node, "aspeed,battery-sensing",
> NULL)) {
> if (data->model_data->bat_sense_sup) {
> @@ -579,6 +629,21 @@ static int aspeed_adc_remove(struct platform_device *pdev)
> return 0;
> }
>
> +static const struct aspeed_adc_trim_locate ast2500_adc_trim = {
> + .offset = 0x154,
> + .field = GENMASK(31, 28),
> +};
> +
> +static const struct aspeed_adc_trim_locate ast2600_adc0_trim = {
> + .offset = 0x5d0,
> + .field = GENMASK(3, 0),
> +};
> +
> +static const struct aspeed_adc_trim_locate ast2600_adc1_trim = {
> + .offset = 0x5d0,
> + .field = GENMASK(7, 4),
> +};
> +
> static const struct aspeed_adc_model_data ast2400_model_data = {
> .model_name = "ast2400-adc",
> .vref_fixed = 2500, // mV
> @@ -598,6 +663,7 @@ static const struct aspeed_adc_model_data ast2500_model_data = {
> .need_prescaler = true,
> .scaler_bit_width = 10,
> .num_channels = 16,
> + .trim_locate = &ast2500_adc_trim,
> };
>
> static const struct aspeed_adc_model_data ast2600_adc0_model_data = {
> @@ -608,6 +674,7 @@ static const struct aspeed_adc_model_data ast2600_adc0_model_data = {
> .bat_sense_sup = true,
> .scaler_bit_width = 16,
> .num_channels = 8,
> + .trim_locate = &ast2600_adc0_trim,
> };
>
> static const struct aspeed_adc_model_data ast2600_adc1_model_data = {
> @@ -618,6 +685,7 @@ static const struct aspeed_adc_model_data ast2600_adc1_model_data = {
> .bat_sense_sup = true,
> .scaler_bit_width = 16,
> .num_channels = 8,
> + .trim_locate = &ast2600_adc1_trim,
> };
>
> static const struct of_device_id aspeed_adc_matches[] = {