iio:proximity:sx9360: Add dt-binding support

Add support to configure sx9360 from dt-binding, to match device
hardware setup.
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20220101203800.290387-4-gwendal@chromium.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/proximity/sx9360.c

@@ -18,6 +18,7 @@
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/pm.h>
+#include <linux/property.h>
 #include <linux/regmap.h>
 
 #include <linux/iio/iio.h>
@@ -64,6 +65,7 @@
 #define SX9360_REG_PROX_CTRL0_PHM	0x41
 #define SX9360_REG_PROX_CTRL0_GAIN_MASK	GENMASK(5, 3)
 #define SX9360_REG_PROX_CTRL0_GAIN_1		0x80
+#define SX9360_REG_PROX_CTRL0_RAWFILT_MASK	GENMASK(2, 0)
 #define SX9360_REG_PROX_CTRL0_RAWFILT_1P50	0x01
 #define SX9360_REG_PROX_CTRL1		0x42
 #define SX9360_REG_PROX_CTRL1_AVGNEG_THRESH_MASK	GENMASK(5, 3)
@@ -657,6 +659,41 @@ static int sx9360_write_raw(struct iio_dev *indio_dev,
 	}
 }
 
+static const struct sx_common_reg_default sx9360_default_regs[] = {
+	{ SX9360_REG_IRQ_MSK, 0x00 },
+	{ SX9360_REG_IRQ_CFG, 0x00 },
+	/*
+	 * The lower 2 bits should not be set as it enable sensors measurements.
+	 * Turning the detection on before the configuration values are set to
+	 * good values can cause the device to return erroneous readings.
+	 */
+	{ SX9360_REG_GNRL_CTRL0, 0x00 },
+	{ SX9360_REG_GNRL_CTRL1, 0x00 },
+	{ SX9360_REG_GNRL_CTRL2, SX9360_REG_GNRL_CTRL2_PERIOD_102MS },
+
+	{ SX9360_REG_AFE_CTRL1, 0x00 },
+	{ SX9360_REG_AFE_PARAM0_PHR, SX9360_REG_AFE_PARAM0_RSVD |
+		SX9360_REG_AFE_PARAM0_RESOLUTION_128 },
+	{ SX9360_REG_AFE_PARAM1_PHR, SX9360_REG_AFE_PARAM1_AGAIN_PHM_6PF |
+		SX9360_REG_AFE_PARAM1_FREQ_83_33HZ },
+	{ SX9360_REG_AFE_PARAM0_PHM, SX9360_REG_AFE_PARAM0_RSVD |
+		SX9360_REG_AFE_PARAM0_RESOLUTION_128 },
+	{ SX9360_REG_AFE_PARAM1_PHM, SX9360_REG_AFE_PARAM1_AGAIN_PHM_6PF |
+		SX9360_REG_AFE_PARAM1_FREQ_83_33HZ },
+
+	{ SX9360_REG_PROX_CTRL0_PHR, SX9360_REG_PROX_CTRL0_GAIN_1 |
+		SX9360_REG_PROX_CTRL0_RAWFILT_1P50 },
+	{ SX9360_REG_PROX_CTRL0_PHM, SX9360_REG_PROX_CTRL0_GAIN_1 |
+		SX9360_REG_PROX_CTRL0_RAWFILT_1P50 },
+	{ SX9360_REG_PROX_CTRL1, SX9360_REG_PROX_CTRL1_AVGNEG_THRESH_16K },
+	{ SX9360_REG_PROX_CTRL2, SX9360_REG_PROX_CTRL2_AVGDEB_2SAMPLES |
+		SX9360_REG_PROX_CTRL2_AVGPOS_THRESH_16K },
+	{ SX9360_REG_PROX_CTRL3, SX9360_REG_PROX_CTRL3_AVGNEG_FILT_2 |
+		SX9360_REG_PROX_CTRL3_AVGPOS_FILT_256 },
+	{ SX9360_REG_PROX_CTRL4, 0x00 },
+	{ SX9360_REG_PROX_CTRL5, SX9360_REG_PROX_CTRL5_PROXTHRESH_32 },
+};
+
 /* Activate all channels and perform an initial compensation. */
 static int sx9360_init_compensation(struct iio_dev *indio_dev)
 {
@@ -676,6 +713,51 @@ static int sx9360_init_compensation(struct iio_dev *indio_dev)
 				       20000, 2000000);
 }
 
+static const struct sx_common_reg_default *
+sx9360_get_default_reg(struct device *dev, int idx,
+		       struct sx_common_reg_default *reg_def)
+{
+	u32 raw = 0, pos = 0;
+	int ret;
+
+	memcpy(reg_def, &sx9360_default_regs[idx], sizeof(*reg_def));
+	switch (reg_def->reg) {
+	case SX9360_REG_AFE_PARAM0_PHR:
+	case SX9360_REG_AFE_PARAM0_PHM:
+		ret = device_property_read_u32(dev, "semtech,resolution", &raw);
+		if (ret)
+			break;
+
+		raw = ilog2(raw) - 3;
+
+		reg_def->def &= ~SX9360_REG_AFE_PARAM0_RESOLUTION_MASK;
+		reg_def->def |= FIELD_PREP(SX9360_REG_AFE_PARAM0_RESOLUTION_MASK, raw);
+		break;
+	case SX9360_REG_PROX_CTRL0_PHR:
+	case SX9360_REG_PROX_CTRL0_PHM:
+		ret = device_property_read_u32(dev, "semtech,proxraw-strength", &raw);
+		if (ret)
+			break;
+
+		reg_def->def &= ~SX9360_REG_PROX_CTRL0_RAWFILT_MASK;
+		reg_def->def |= FIELD_PREP(SX9360_REG_PROX_CTRL0_RAWFILT_MASK, raw);
+		break;
+	case SX9360_REG_PROX_CTRL3:
+		ret = device_property_read_u32(dev, "semtech,avg-pos-strength",
+					       &pos);
+		if (ret)
+			break;
+
+		/* Powers of 2, except for a gap between 16 and 64 */
+		raw = clamp(ilog2(pos), 3, 11) - (pos >= 32 ? 4 : 3);
+		reg_def->def &= ~SX9360_REG_PROX_CTRL3_AVGPOS_FILT_MASK;
+		reg_def->def |= FIELD_PREP(SX9360_REG_PROX_CTRL3_AVGPOS_FILT_MASK, raw);
+		break;
+	}
+
+	return reg_def;
+}
+
 static int sx9360_check_whoami(struct device *dev, struct iio_dev *indio_dev)
 {
 	/*
@@ -695,12 +777,14 @@ static const struct sx_common_chip_info sx9360_chip_info = {
 	.mask_enable_chan = SX9360_REG_GNRL_CTRL0_PHEN_MASK,
 	.stat_offset = 3,
 	.num_channels = SX9360_NUM_CHANNELS,
+	.num_default_regs = ARRAY_SIZE(sx9360_default_regs),
 
 	.ops = {
 		.read_prox_data = sx9360_read_prox_data,
 		.check_whoami = sx9360_check_whoami,
 		.init_compensation = sx9360_init_compensation,
 		.wait_for_sample = sx9360_wait_for_sample,
+		.get_default_reg = sx9360_get_default_reg,
 	},
 
 	.iio_channels = sx9360_channels,