iio: adc: sc27xx: structure adjustment and optimization

Introduce one variant device data structure to be compatible
with SC2731 PMIC since it has different scale and ratio calculation
and so on. also rename the SC27xx to SC2731 for some definition
and function.

Co-developed-by: Yuming Zhu <[e-mail]>
Signed-off-by: Yuming Zhu <[e-mail]>
Signed-off-by: Cixi Geng <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/adc/sc27xx_adc.c

···
 #include <linux/slab.h>
 
 /* PMIC global registers definition */
-#define SC27XX_MODULE_EN		0xc08
+#define SC2731_MODULE_EN		0xc08
 #define SC27XX_MODULE_ADC_EN		BIT(5)
-#define SC27XX_ARM_CLK_EN		0xc10
+#define SC2731_ARM_CLK_EN		0xc10
 #define SC27XX_CLK_ADC_EN		BIT(5)
 #define SC27XX_CLK_ADC_CLK_EN		BIT(6)
 
···
 	int channel_scale[SC27XX_ADC_CHANNEL_MAX];
 	u32 base;
 	int irq;
+	const struct sc27xx_adc_variant_data *var_data;
+};
+
+/*
+ * Since different PMICs of SC27xx series can have different
+ * address and ratio, we should save ratio config and base
+ * in the device data structure.
+ */
+struct sc27xx_adc_variant_data {
+	u32 module_en;
+	u32 clk_en;
+	u32 scale_shift;
+	u32 scale_mask;
+	const struct sc27xx_adc_linear_graph *bscale_cal;
+	const struct sc27xx_adc_linear_graph *sscale_cal;
+	void (*init_scale)(struct sc27xx_adc_data *data);
+	int (*get_ratio)(int channel, int scale);
 };
 
 struct sc27xx_adc_linear_graph {
···
 	size_t len;
 
 	if (big_scale) {
-		calib_graph = &sc2731_big_scale_graph_calib;
+		calib_graph = data->var_data->bscale_cal;
 		graph = &big_scale_graph;
 		cell_name = "big_scale_calib";
 	} else {
-		calib_graph = &sc2731_small_scale_graph_calib;
+		calib_graph = data->var_data->sscale_cal;
 		graph = &small_scale_graph;
 		cell_name = "small_scale_calib";
 	}
···
 	return 0;
 }
 
-static int sc27xx_adc_get_ratio(int channel, int scale)
+static int sc2731_adc_get_ratio(int channel, int scale)
 {
 	switch (channel) {
 	case 1:
···
 		return SC27XX_VOLT_RATIO(1, 1);
 	}
 	return SC27XX_VOLT_RATIO(1, 1);
+}
+
+/*
+ * According to the datasheet set specific value on some channel.
+ */
+static void sc2731_adc_scale_init(struct sc27xx_adc_data *data)
+{
+	int i;
+	/*
+	 * In the current software design, SC2731 support 2 scales,
+	 * channels 5 uses big scale, others use smale.
+	 */
+	for (i = 0; i < SC27XX_ADC_CHANNEL_MAX; i++) {
+		switch (i) {
+		case 5:
+			data->channel_scale[i] = 1;
+			break;
+		default:
+			data->channel_scale[i] = 0;
+			break;
+		}
+	}
 }
 
 static int sc27xx_adc_read(struct sc27xx_adc_data *data, int channel,
···
 		goto disable_adc;
 
 	/* Configure the channel id and scale */
-	tmp = (scale << SC27XX_ADC_SCALE_SHIFT) & SC27XX_ADC_SCALE_MASK;
+	tmp = (scale << data->var_data->scale_shift) & data->var_data->scale_mask;
 	tmp |= channel & SC27XX_ADC_CHN_ID_MASK;
 	ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CH_CFG,
-				 SC27XX_ADC_CHN_ID_MASK | SC27XX_ADC_SCALE_MASK,
+				 SC27XX_ADC_CHN_ID_MASK |
+				 data->var_data->scale_mask,
 				 tmp);
 	if (ret)
 		goto disable_adc;
···
 				  int channel, int scale,
 				  u32 *div_numerator, u32 *div_denominator)
 {
-	u32 ratio = sc27xx_adc_get_ratio(channel, scale);
+	u32 ratio;
 
+	ratio = data->var_data->get_ratio(channel, scale);
 	*div_numerator = ratio >> SC27XX_RATIO_NUMERATOR_OFFSET;
 	*div_denominator = ratio & SC27XX_RATIO_DENOMINATOR_MASK;
 }
···
 {
 	int ret;
 
-	ret = regmap_update_bits(data->regmap, SC27XX_MODULE_EN,
+	ret = regmap_update_bits(data->regmap, data->var_data->module_en,
 				 SC27XX_MODULE_ADC_EN, SC27XX_MODULE_ADC_EN);
 	if (ret)
 		return ret;
 
 	/* Enable ADC work clock and controller clock */
-	ret = regmap_update_bits(data->regmap, SC27XX_ARM_CLK_EN,
+	ret = regmap_update_bits(data->regmap, data->var_data->clk_en,
 				 SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN,
 				 SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN);
 	if (ret)
···
 	return 0;
 
 disable_clk:
-	regmap_update_bits(data->regmap, SC27XX_ARM_CLK_EN,
+	regmap_update_bits(data->regmap, data->var_data->clk_en,
 			   SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0);
 disable_adc:
-	regmap_update_bits(data->regmap, SC27XX_MODULE_EN,
+	regmap_update_bits(data->regmap, data->var_data->module_en,
 			   SC27XX_MODULE_ADC_EN, 0);
 
 	return ret;
···
 	struct sc27xx_adc_data *data = _data;
 
 	/* Disable ADC work clock and controller clock */
-	regmap_update_bits(data->regmap, SC27XX_ARM_CLK_EN,
+	regmap_update_bits(data->regmap, data->var_data->clk_en,
 			   SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0);
 
-	regmap_update_bits(data->regmap, SC27XX_MODULE_EN,
+	regmap_update_bits(data->regmap, data->var_data->module_en,
 			   SC27XX_MODULE_ADC_EN, 0);
 }
+
+static const struct sc27xx_adc_variant_data sc2731_data = {
+	.module_en = SC2731_MODULE_EN,
+	.clk_en = SC2731_ARM_CLK_EN,
+	.scale_shift = SC27XX_ADC_SCALE_SHIFT,
+	.scale_mask = SC27XX_ADC_SCALE_MASK,
+	.bscale_cal = &sc2731_big_scale_graph_calib,
+	.sscale_cal = &sc2731_small_scale_graph_calib,
+	.init_scale = sc2731_adc_scale_init,
+	.get_ratio = sc2731_adc_get_ratio,
+};
 
 static int sc27xx_adc_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct sc27xx_adc_data *sc27xx_data;
+	const struct sc27xx_adc_variant_data *pdata;
 	struct iio_dev *indio_dev;
 	int ret;
+
+	pdata = of_device_get_match_data(dev);
+	if (!pdata) {
+		dev_err(dev, "No matching driver data found\n");
+		return -EINVAL;
+	}
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*sc27xx_data));
 	if (!indio_dev)
···
 	}
 
 	sc27xx_data->dev = dev;
+	sc27xx_data->var_data = pdata;
+	sc27xx_data->var_data->init_scale(sc27xx_data);
 
 	ret = sc27xx_adc_enable(sc27xx_data);
 	if (ret) {
···
 }
 
 static const struct of_device_id sc27xx_adc_of_match[] = {
-	{ .compatible = "sprd,sc2731-adc", },
+	{ .compatible = "sprd,sc2731-adc", .data = &sc2731_data},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sc27xx_adc_of_match);