iio: adc: exynos_adc: add support for s3c64xx adc

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>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 27 insertions, 1 deletions

diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
index fc9dfc23ecb7..62631a778b1f 100644
--- a/drivers/iio/adc/exynos_adc.c
+++ b/drivers/iio/adc/exynos_adc.c
@@ -40,7 +40,7 @@
 #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_DLY(x)           ((x) + 0x08)
 #define ADC_V1_DATX(x)          ((x) + 0x0C)
@@ -61,6 +61,9 @@
 #define ADC_V1_CON_PRSCLV(x)    (((x) & 0xFF) << 6)
 #define ADC_V1_CON_STANDBY      (1u << 2)
 
+/* Bit definitions for S3C2410 ADC */
+#define ADC_S3C2410_CON_SELMUX(x) (((x) & 7) << 3)
+
 /* Bit definitions for ADC_V2 */
 #define ADC_V2_CON1_SOFT_RESET  (1u << 2)
 
@@ -217,6 +220,26 @@ static const struct exynos_adc_data exynos_adc_v1_data = {
         .start_conv     = exynos_adc_v1_start_conv,
 };
 
+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(0x7);
+        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_v2_init_hw(struct exynos_adc *info)
 {
         u32 con1, con2;
@@ -285,6 +308,9 @@ static const struct exynos_adc_data exynos3250_adc_data = {
 
 static const struct of_device_id exynos_adc_match[] = {
         {
+                .compatible = "samsung,s3c6410-adc",
+                .data = &exynos_adc_s3c64xx_data,
+        }, {
                 .compatible = "samsung,exynos-adc-v1",
                 .data = &exynos_adc_v1_data,
         }, {