[PATCH 1/2] iio: exynos-adc: add support for s3c64xx adc

[Arnd Bergmann <arnd@arndb.de>]

The ADC in s3c64xx is almost the same as exynosv1, but
has a different 'select' method. Adding this here will be
helpful to move over the existing s3c64xx platform from the
legacy plat-samsung/adc driver to the new exynos-adc.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
[In reply to Exynos3250 ADC support, adding Heiko and Ben]

I spent way too much time this week trying to clean up the
old plat-samsung/adc.c driver as preparation for s3c64xx multiplatform
support. Eventually I figured out that all that code is much simpler
done using the new driver. This adds support for s3c64xx in
samsung-adc.c, similar code changes can be done to support the
various s3c24xx variants as well.

This first patch should be fairly straightforward but is not tested
yet. The second patch is more tricky.

Both are based on the exynos3250 patches sent by Chanwoo Choi.

diff --git a/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt b/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt
index 26232f98d8c5..f84e9250429b 100644
--- a/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt
+++ b/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt
@@ -11,11 +11,21 @@ New driver handles the following
 
 Required properties:
 - compatible:		Must be "samsung,exynos-adc-v1"
-				for exynos4412/5250 controllers.
+				for exynos4412/5250 and s5pv210 controllers.
 			Must be "samsung,exynos-adc-v2" for
 				future controllers.
 			Must be "samsung,exynos3250-adc-v2" for
 				controllers compatible with ADC of Exynos3250.
+			Must be "samsung,s3c2410-adc" for
+				the ADC in s3c2410 and compatibles
+			Must be "samsung,s3c2416-adc" for
+				the ADC in s3c2416 and compatibles
+			Must be "samsung,s3c2440-adc" for
+				the ADC in s3c2440 and compatibles
+			Must be "samsung,s3c2440-adc" for
+				the ADC in s3c2440 and compatibles
+			Must be "samsung,s3c2443-adc" for
+				the ADC in s3c2443 and compatibles
 - reg:			Contains ADC register address range (base address and
 			length) and the address of the phy enable register.
 - interrupts: 		Contains the interrupt information for the timer. The
diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
index b63e88247eb2..5f95638513d2 100644
--- a/drivers/iio/adc/exynos_adc.c
+++ b/drivers/iio/adc/exynos_adc.c
@@ -39,12 +39,16 @@
 #include <linux/iio/machine.h>
 #include <linux/iio/driver.h>
 
-/* EXYNOS4412/5250 ADC_V1 registers definitions */
+/* S3C/EXYNOS4412/5250 ADC_V1 registers definitions */
 #define ADC_V1_CON(x)		((x) + 0x00)
+#define ADC_V1_TSC(x)		((x) + 0x04)
 #define ADC_V1_DLY(x)		((x) + 0x08)
 #define ADC_V1_DATX(x)		((x) + 0x0C)
+#define ADC_V1_DATY(x)		((x) + 0x10)
+#define ADC_V1_UPDN(x)		((x) + 0x14)
 #define ADC_V1_INTCLR(x)	((x) + 0x18)
 #define ADC_V1_MUX(x)		((x) + 0x1c)
+#define ADC_V1_CLRINTPNDNUP(x)	((x) + 0x20)
 
 /* Future ADC_V2 registers definitions */
 #define ADC_V2_CON1(x)		((x) + 0x00)
@@ -60,6 +64,30 @@
 #define ADC_V1_CON_PRSCLV(x)	(((x) & 0xFF) << 6)
 #define ADC_V1_CON_STANDBY	(1u << 2)
 
+#define ADC_S3C2410_CON_SELMUX(x) (((x)&0x7)<<3)
+
+/* ADCTSC Register Bits */
+#define ADC_S3C2443_TSC_UD_SEN		(1<<8)
+#define ADC_S3C2410_TSC_YM_SEN		(1<<7)
+#define ADC_S3C2410_TSC_YP_SEN		(1<<6)
+#define ADC_S3C2410_TSC_XM_SEN		(1<<5)
+#define ADC_S3C2410_TSC_XP_SEN		(1<<4)
+#define ADC_S3C2410_TSC_PULL_UP_DISABLE	(1<<3)
+#define ADC_S3C2410_TSC_AUTO_PST	(1<<2)
+#define ADC_S3C2410_TSC_XY_PST(x)	(((x)&0x3)<<0)
+
+#define ADC_TSC_WAIT4INT (ADC_S3C2410_TSC_YM_SEN | \
+			 ADC_S3C2410_TSC_YP_SEN | \
+			 ADC_S3C2410_TSC_XP_SEN | \
+			 ADC_S3C2410_TSC_XY_PST(3))
+
+#define ADC_TSC_AUTOPST	(ADC_S3C2410_TSC_YM_SEN | \
+			 ADC_S3C2410_TSC_YP_SEN | \
+			 ADC_S3C2410_TSC_XP_SEN | \
+			 ADC_S3C2410_TSC_AUTO_PST | \
+			 ADC_S3C2410_TSC_XY_PST(0))
+
+
 /* Bit definitions for ADC_V2 */
 #define ADC_V2_CON1_SOFT_RESET	(1u << 2)
 
@@ -195,6 +223,26 @@ static void exynos_adc_v1_clear_irq(struct exynos_adc *info)
 	writel(1, ADC_V1_INTCLR(info->regs));
 }
 
+static void exynos_adc_s3c64xx_start_conv(struct exynos_adc *info,
+				     unsigned long addr)
+{
+	u32 con1;
+
+	con1 = readl(ADC_V1_CON(info->regs));
+	con1 &= ~ADC_S3C2410_CON_SELMUX(7);
+	con1 |= ADC_S3C2410_CON_SELMUX(addr);
+	writel(con1 | ADC_CON_EN_START, ADC_V1_CON(info->regs));
+}
+
+static struct exynos_adc_data const exynos_adc_s3c64xx_data = {
+	.num_channels	= MAX_ADC_V1_CHANNELS,
+
+	.init_hw	= exynos_adc_v1_init_hw,
+	.exit_hw	= exynos_adc_v1_exit_hw,
+	.clear_irq	= exynos_adc_v1_clear_irq,
+	.start_conv	= exynos_adc_s3c64xx_start_conv,
+};
+
 static void exynos_adc_v1_start_conv(struct exynos_adc *info,
 				     unsigned long addr)
 {
@@ -280,6 +328,9 @@ static struct exynos_adc_data const exynos3250_adc_v2_data = {
 
 static const struct of_device_id exynos_adc_match[] = {
 	{
+		.compatible = "samsung,s3c64100-adc",
+		.data = &exynos_adc_s3c64xx_data,
+	}, {
 		.compatible = "samsung,exynos-adc-v1",
 		.data = (void *)&exynos_adc_v1_data,
 	}, {