[PATCH v1 3/3] iio: adc: meson: init voltage control bits

George Stark
2023-07-15T11:07:49Z

Define and init voltage configuration bits. Those bits are inited in
vendor boot code (bl2, bl33) already so do it in the driver to not depend
on other code.

Introduced bits:
REG11[0] - selects Vref. 0 - calibration voltage, 1 - VDDA. txlx and later
SoCs support VDDA or calibration voltage as Vref, but others
support only calibration voltage. For newer platforms vendor
uses VDDA as default.
REG11[1] - reserved bit. g12a and later SoCs must write 1, others SoCs
write 0.
REG11[5] - Vref voltage. 0 - 0.9v, 1 - 1.8v. g12a and later SoCs must
write 0, others SoCs write 1.
REG11[6] - selects common-mode voltage, 0: from AVDD, 1: from Vref.
g12a and later SoCs must write 0, others SoCs write 1.

Signed-off-by: George Stark <gnstark@sberdevices.ru>
---
drivers/iio/adc/meson_saradc.c | 48 ++++++++++++++++++++++++++++++++++
1 file changed, 48 insertions(+)

diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index 806ba7cd7320..05fb30b81b8d 100644
--- a/drivers/iio/adc/meson_saradc.c
+++ b/drivers/iio/adc/meson_saradc.c
@@ -156,6 +156,10 @@
*/
#define MESON_SAR_ADC_REG11 0x2c
#define MESON_SAR_ADC_REG11_BANDGAP_EN BIT(13)
+ #define MESON_SAR_ADC_REG11_CMV_SEL BIT(6)
+ #define MESON_SAR_ADC_REG11_VREF_VOLTAGE BIT(5)
+ #define MESON_SAR_ADC_REG11_EOC BIT(1)
+ #define MESON_SAR_ADC_REG11_VREF_SEL BIT(0)

#define MESON_SAR_ADC_REG13 0x34
#define MESON_SAR_ADC_REG13_12BIT_CALIBRATION_MASK GENMASK(13, 8)
@@ -216,6 +220,11 @@
.datasheet_name = "SAR_ADC_MUX_"#_sel, \
}

+enum meson_sar_adc_vref_sel {
+ VREF_CALIBATION_VOLTAGE = 0,
+ VREF_VDDA = 1,
+};
+
enum meson_sar_adc_avg_mode {
NO_AVERAGING = 0x0,
MEAN_AVERAGING = 0x1,
@@ -314,6 +323,12 @@ struct meson_sar_adc_param {
unsigned int temperature_multiplier;
unsigned int temperature_divider;
u8 disable_ring_counter;
+ bool has_reg11;
+ bool has_vref_select;
+ u8 vref_select;
+ u8 cmv_select;
+ u8 adc_eoc;
+ enum meson_sar_adc_vref_sel vref_volatge;
};

struct meson_sar_adc_data {
@@ -974,6 +989,29 @@ static int meson_sar_adc_init(struct iio_dev *indio_dev)
MESON_SAR_ADC_REG3_CTRL_CONT_RING_COUNTER_EN,
regval);

+ if (priv->param->has_reg11) {
+ regval = FIELD_PREP(MESON_SAR_ADC_REG11_EOC, priv->param->adc_eoc);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
+ MESON_SAR_ADC_REG11_EOC, regval);
+
+ if (priv->param->has_vref_select) {
+ regval = FIELD_PREP(MESON_SAR_ADC_REG11_VREF_SEL,
+ priv->param->vref_select);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
+ MESON_SAR_ADC_REG11_VREF_SEL, regval);
+ }
+
+ regval = FIELD_PREP(MESON_SAR_ADC_REG11_VREF_VOLTAGE,
+ priv->param->vref_volatge);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
+ MESON_SAR_ADC_REG11_VREF_VOLTAGE, regval);
+
+ regval = FIELD_PREP(MESON_SAR_ADC_REG11_CMV_SEL,
+ priv->param->cmv_select);
+ regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
+ MESON_SAR_ADC_REG11_CMV_SEL, regval);
+ }
+
ret = clk_set_parent(priv->adc_sel_clk, priv->clkin);
if (ret)
return dev_err_probe(dev, ret, "failed to set adc parent to clkin\n");
@@ -1195,6 +1233,9 @@ static const struct meson_sar_adc_param meson_sar_adc_gxbb_param = {
.bandgap_reg = MESON_SAR_ADC_REG11,
.regmap_config = &meson_sar_adc_regmap_config_gxbb,
.resolution = 10,
+ .has_reg11 = true,
+ .vref_volatge = 1,
+ .cmv_select = 1,
};

static const struct meson_sar_adc_param meson_sar_adc_gxl_param = {
@@ -1204,6 +1245,9 @@ static const struct meson_sar_adc_param meson_sar_adc_gxl_param = {
.regmap_config = &meson_sar_adc_regmap_config_gxbb,
.resolution = 12,
.disable_ring_counter = 1,
+ .has_reg11 = true,
+ .vref_volatge = 1,
+ .cmv_select = 1,
};

static const struct meson_sar_adc_param meson_sar_adc_g12a_param = {
@@ -1213,6 +1257,10 @@ static const struct meson_sar_adc_param meson_sar_adc_g12a_param = {
.regmap_config = &meson_sar_adc_regmap_config_gxbb,
.resolution = 12,
.disable_ring_counter = 1,
+ .has_reg11 = true,
+ .adc_eoc = 1,
+ .has_vref_select = true,
+ .vref_select = VREF_VDDA,
};

static const struct meson_sar_adc_data meson_sar_adc_meson8_data = {
--
2.38.4