rockchip: adc: rockchip-saradc: factor out channel_data callback

SARADC v1 and v2 have a different way of reading data, therefore let's
abstract this function so that it can be provided from the udevice.data
pointer.

Cc: Quentin Schulz <foss+uboot@0leil.net>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
diff --git a/drivers/adc/rockchip-saradc.c b/drivers/adc/rockchip-saradc.c
index 4a84255..1cc57be 100644
--- a/drivers/adc/rockchip-saradc.c
+++ b/drivers/adc/rockchip-saradc.c
@@ -37,6 +37,7 @@
 	int				num_bits;
 	int				num_channels;
 	unsigned long			clk_rate;
+	int (*channel_data)(struct udevice *dev, int channel, unsigned int *data);
 };
 
 struct rockchip_saradc_priv {
@@ -45,16 +46,10 @@
 	const struct rockchip_saradc_data	*data;
 };
 
-int rockchip_saradc_channel_data(struct udevice *dev, int channel,
-				 unsigned int *data)
+int rockchip_saradc_channel_data_v1(struct udevice *dev, int channel,
+				    unsigned int *data)
 {
 	struct rockchip_saradc_priv *priv = dev_get_priv(dev);
-	struct adc_uclass_plat *uc_pdata = dev_get_uclass_plat(dev);
-
-	if (channel != priv->active_channel) {
-		pr_err("Requested channel is not active!");
-		return -EINVAL;
-	}
 
 	if ((readl(&priv->regs.v1->ctrl) & SARADC_CTRL_IRQ_STATUS) !=
 	    SARADC_CTRL_IRQ_STATUS)
@@ -62,7 +57,6 @@
 
 	/* Read value */
 	*data = readl(&priv->regs.v1->data);
-	*data &= uc_pdata->data_mask;
 
 	/* Power down adc */
 	writel(0, &priv->regs.v1->ctrl);
@@ -70,6 +64,30 @@
 	return 0;
 }
 
+int rockchip_saradc_channel_data(struct udevice *dev, int channel,
+				 unsigned int *data)
+{
+	struct rockchip_saradc_priv *priv = dev_get_priv(dev);
+	struct adc_uclass_plat *uc_pdata = dev_get_uclass_plat(dev);
+	int ret;
+
+	if (channel != priv->active_channel) {
+		pr_err("Requested channel is not active!");
+		return -EINVAL;
+	}
+
+	ret = priv->data->channel_data(dev, channel, data);
+	if (ret) {
+		if (ret != -EBUSY)
+			pr_err("Error reading channel data, %d!", ret);
+		return ret;
+	}
+
+	*data &= uc_pdata->data_mask;
+
+	return 0;
+}
+
 int rockchip_saradc_start_channel(struct udevice *dev, int channel)
 {
 	struct rockchip_saradc_priv *priv = dev_get_priv(dev);
@@ -174,18 +192,21 @@
 	.num_bits = 10,
 	.num_channels = 3,
 	.clk_rate = 1000000,
+	.channel_data = rockchip_saradc_channel_data_v1,
 };
 
 static const struct rockchip_saradc_data rk3066_tsadc_data = {
 	.num_bits = 12,
 	.num_channels = 2,
 	.clk_rate = 50000,
+	.channel_data = rockchip_saradc_channel_data_v1,
 };
 
 static const struct rockchip_saradc_data rk3399_saradc_data = {
 	.num_bits = 10,
 	.num_channels = 6,
 	.clk_rate = 1000000,
+	.channel_data = rockchip_saradc_channel_data_v1,
 };
 
 static const struct udevice_id rockchip_saradc_ids[] = {