[PATCH 21/23] iio: adc: exynos-adc: Add support for ADC V3 controller

[Alim Akhtar]

Exynos's ADC-V3 has some difference in registers set, number of
programmable channels (16 channel) etc. This patch adds support for ADC-V3
controller version.

Cc: linux-fsd@xxxxxxxxx
Cc: jic23@xxxxxxxxxx
Cc: linux-iio@xxxxxxxxxxxxxxx
Signed-off-by: Tamseel Shams <m.shams@xxxxxxxxxxx>
Signed-off-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
---
 drivers/iio/adc/exynos_adc.c | 74 +++++++++++++++++++++++++++++++++++-
 1 file changed, 72 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
index 3b3868aa2533..61752e798fd6 100644
--- a/drivers/iio/adc/exynos_adc.c
+++ b/drivers/iio/adc/exynos_adc.c
@@ -55,6 +55,11 @@
 #define ADC_V2_INT_ST(x)	((x) + 0x14)
 #define ADC_V2_VER(x)		((x) + 0x20)
 
+/* ADC_V3 register definitions */
+#define ADC_V3_DAT(x)			((x) + 0x08)
+#define ADC_V3_DAT_SUM(x)		((x) + 0x0C)
+#define ADC_V3_DBG_DATA(x)		((x) + 0x1C)
+
 /* Bit definitions for ADC_V1 */
 #define ADC_V1_CON_RES		(1u << 16)
 #define ADC_V1_CON_PRSCEN	(1u << 14)
@@ -92,6 +97,7 @@
 
 /* Bit definitions for ADC_V2 */
 #define ADC_V2_CON1_SOFT_RESET	(1u << 2)
+#define ADC_V2_CON1_SOFT_NON_RESET	(1u << 1)
 
 #define ADC_V2_CON2_OSEL	(1u << 10)
 #define ADC_V2_CON2_ESEL	(1u << 9)
@@ -100,6 +106,7 @@
 #define ADC_V2_CON2_ACH_SEL(x)	(((x) & 0xF) << 0)
 #define ADC_V2_CON2_ACH_MASK	0xF
 
+#define MAX_ADC_V3_CHANNELS		16
 #define MAX_ADC_V2_CHANNELS		10
 #define MAX_ADC_V1_CHANNELS		8
 #define MAX_EXYNOS3250_ADC_CHANNELS	2
@@ -164,6 +171,7 @@ struct exynos_adc_data {
 	void (*exit_hw)(struct exynos_adc *info);
 	void (*clear_irq)(struct exynos_adc *info);
 	void (*start_conv)(struct exynos_adc *info, unsigned long addr);
+	irqreturn_t (*adc_isr)(int irq, void *dev_id);
 };
 
 static void exynos_adc_unprepare_clk(struct exynos_adc *info)
@@ -484,6 +492,59 @@ static const struct exynos_adc_data exynos7_adc_data = {
 	.start_conv	= exynos_adc_v2_start_conv,
 };
 
+static void exynos_adc_v3_init_hw(struct exynos_adc *info)
+{
+	u32 con2;
+
+	writel(ADC_V2_CON1_SOFT_RESET, ADC_V2_CON1(info->regs));
+
+	writel(ADC_V2_CON1_SOFT_NON_RESET, ADC_V2_CON1(info->regs));
+
+	con2 = ADC_V2_CON2_C_TIME(6);
+	writel(con2, ADC_V2_CON2(info->regs));
+
+	/* Enable interrupts */
+	writel(1, ADC_V2_INT_EN(info->regs));
+}
+
+static void exynos_adc_v3_exit_hw(struct exynos_adc *info)
+{
+	u32 con2;
+
+	con2 = readl(ADC_V2_CON2(info->regs));
+	con2 &= ~ADC_V2_CON2_C_TIME(7);
+	writel(con2, ADC_V2_CON2(info->regs));
+
+	/* Disable interrupts */
+	writel(0, ADC_V2_INT_EN(info->regs));
+}
+
+static irqreturn_t exynos_adc_v3_isr(int irq, void *dev_id)
+{
+	struct exynos_adc *info = (struct exynos_adc *)dev_id;
+	u32 mask = info->data->mask;
+
+	info->value = readl(ADC_V3_DAT(info->regs)) & mask;
+
+	if (info->data->clear_irq)
+		info->data->clear_irq(info);
+
+	complete(&info->completion);
+
+	return IRQ_HANDLED;
+}
+
+static const struct exynos_adc_data exynos_adc_v3_adc_data = {
+	.num_channels	= MAX_ADC_V3_CHANNELS,
+	.mask		= ADC_DATX_MASK, /* 12 bit ADC resolution */
+
+	.init_hw	= exynos_adc_v3_init_hw,
+	.exit_hw	= exynos_adc_v3_exit_hw,
+	.clear_irq	= exynos_adc_v2_clear_irq,
+	.start_conv	= exynos_adc_v2_start_conv,
+	.adc_isr	= exynos_adc_v3_isr,
+};
+
 static const struct of_device_id exynos_adc_match[] = {
 	{
 		.compatible = "samsung,s3c2410-adc",
@@ -518,6 +579,9 @@ static const struct of_device_id exynos_adc_match[] = {
 	}, {
 		.compatible = "samsung,exynos7-adc",
 		.data = &exynos7_adc_data,
+	}, {
+		.compatible = "samsung,exynos-adc-v3",
+		.data = &exynos_adc_v3_adc_data,
 	},
 	{},
 };
@@ -719,6 +783,12 @@ static const struct iio_chan_spec exynos_adc_iio_channels[] = {
 	ADC_CHANNEL(7, "adc7"),
 	ADC_CHANNEL(8, "adc8"),
 	ADC_CHANNEL(9, "adc9"),
+	ADC_CHANNEL(10, "adc10"),
+	ADC_CHANNEL(11, "adc11"),
+	ADC_CHANNEL(12, "adc12"),
+	ADC_CHANNEL(13, "adc13"),
+	ADC_CHANNEL(14, "adc14"),
+	ADC_CHANNEL(15, "adc15"),
 };
 
 static int exynos_adc_remove_devices(struct device *dev, void *c)
@@ -885,8 +955,8 @@ static int exynos_adc_probe(struct platform_device *pdev)
 
 	mutex_init(&info->lock);
 
-	ret = request_irq(info->irq, exynos_adc_isr,
-					0, dev_name(&pdev->dev), info);
+	ret = request_irq(info->irq, info->data->adc_isr ? info->data->adc_isr :
+				exynos_adc_isr, 0, dev_name(&pdev->dev), info);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed requesting irq, irq = %d\n",
 							info->irq);
-- 
2.17.1