iio: adc: exynos_adc: Add support for s3c24xx ADC

This patch add support for s3c2410/s3c2416/s3c2440/s3c2443 ADC. The s3c24xx
is alomost same as ADCv1. But, There are a little difference as following:
- ADCMUX register address
- ADCDAT mask (10 bit or 12 bit ADC resolution according to SoC version)
- s3c24xx/s3c64xx has not included ADC_PHY enable register

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

2 files changed, 101 insertions, 10 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 6655fd41acd9..88bdc8f612e2 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -129,7 +129,7 @@ config AT91_ADC
 
 config EXYNOS_ADC
         tristate "Exynos ADC driver support"
-        depends on ARCH_EXYNOS || (OF && COMPILE_TEST)
+        depends on ARCH_EXYNOS || ARCH_S3C24XX || ARCH_S3C64XX || (OF && COMPILE_TEST)
         help
           Core support for the ADC block found in the Samsung EXYNOS series
           of SoCs for drivers such as the touchscreen and hwmon to use to share
diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
index 62631a778b1f..c59012d2d06f 100644
--- a/drivers/iio/adc/exynos_adc.c
+++ b/drivers/iio/adc/exynos_adc.c
@@ -47,6 +47,9 @@
 #define ADC_V1_INTCLR(x)        ((x) + 0x18)
 #define ADC_V1_MUX(x)           ((x) + 0x1c)
 
+/* S3C2410 ADC registers definitions */
+#define ADC_S3C2410_MUX(x)      ((x) + 0x18)
+
 /* Future ADC_V2 registers definitions */
 #define ADC_V2_CON1(x)          ((x) + 0x00)
 #define ADC_V2_CON2(x)          ((x) + 0x04)
@@ -63,6 +66,8 @@
 
 /* Bit definitions for S3C2410 ADC */
 #define ADC_S3C2410_CON_SELMUX(x) (((x) & 7) << 3)
+#define ADC_S3C2410_DATX_MASK   0x3FF
+#define ADC_S3C2416_CON_RES_SEL (1u << 3)
 
 /* Bit definitions for ADC_V2 */
 #define ADC_V2_CON1_SOFT_RESET  (1u << 2)
@@ -80,6 +85,7 @@
 
 /* Bit definitions common for ADC_V1 and ADC_V2 */
 #define ADC_CON_EN_START        (1u << 0)
+#define ADC_CON_EN_START_MASK   (0x3 << 0)
 #define ADC_DATX_MASK           0xFFF
 
 #define EXYNOS_ADC_TIMEOUT      (msecs_to_jiffies(100))
@@ -103,6 +109,8 @@ struct exynos_adc {
 struct exynos_adc_data {
         int num_channels;
         bool needs_sclk;
+        bool needs_adc_phy;
+        u32 mask;
 
         void (*init_hw)(struct exynos_adc *info);
         void (*exit_hw)(struct exynos_adc *info);
@@ -174,7 +182,8 @@ static void exynos_adc_v1_init_hw(struct exynos_adc *info)
 {
         u32 con1;
 
-        writel(1, info->enable_reg);
+        if (info->data->needs_adc_phy)
+                writel(1, info->enable_reg);
 
         /* set default prescaler values and Enable prescaler */
         con1 =  ADC_V1_CON_PRSCLV(49) | ADC_V1_CON_PRSCEN;
@@ -188,7 +197,8 @@ static void exynos_adc_v1_exit_hw(struct exynos_adc *info)
 {
         u32 con;
 
-        writel(0, info->enable_reg);
+        if (info->data->needs_adc_phy)
+                writel(0, info->enable_reg);
 
         con = readl(ADC_V1_CON(info->regs));
         con |= ADC_V1_CON_STANDBY;
@@ -213,6 +223,8 @@ static void exynos_adc_v1_start_conv(struct exynos_adc *info,
 
 static const struct exynos_adc_data exynos_adc_v1_data = {
         .num_channels   = MAX_ADC_V1_CHANNELS,
+        .mask           = ADC_DATX_MASK,        /* 12 bit ADC resolution */
+        .needs_adc_phy  = true,
 
         .init_hw        = exynos_adc_v1_init_hw,
         .exit_hw        = exynos_adc_v1_exit_hw,
@@ -220,6 +232,53 @@ static const struct exynos_adc_data exynos_adc_v1_data = {
         .start_conv     = exynos_adc_v1_start_conv,
 };
 
+static void exynos_adc_s3c2416_start_conv(struct exynos_adc *info,
+                                          unsigned long addr)
+{
+        u32 con1;
+
+        /* Enable 12 bit ADC resolution */
+        con1 = readl(ADC_V1_CON(info->regs));
+        con1 |= ADC_S3C2416_CON_RES_SEL;
+        writel(con1, ADC_V1_CON(info->regs));
+
+        /* Select channel for S3C2416 */
+        writel(addr, ADC_S3C2410_MUX(info->regs));
+
+        con1 = readl(ADC_V1_CON(info->regs));
+        writel(con1 | ADC_CON_EN_START, ADC_V1_CON(info->regs));
+}
+
+static struct exynos_adc_data const exynos_adc_s3c2416_data = {
+        .num_channels   = MAX_ADC_V1_CHANNELS,
+        .mask           = ADC_DATX_MASK,        /* 12 bit ADC resolution */
+
+        .init_hw        = exynos_adc_v1_init_hw,
+        .exit_hw        = exynos_adc_v1_exit_hw,
+        .start_conv     = exynos_adc_s3c2416_start_conv,
+};
+
+static void exynos_adc_s3c2443_start_conv(struct exynos_adc *info,
+                                          unsigned long addr)
+{
+        u32 con1;
+
+        /* Select channel for S3C2433 */
+        writel(addr, ADC_S3C2410_MUX(info->regs));
+
+        con1 = readl(ADC_V1_CON(info->regs));
+        writel(con1 | ADC_CON_EN_START, ADC_V1_CON(info->regs));
+}
+
+static struct exynos_adc_data const exynos_adc_s3c2443_data = {
+        .num_channels   = MAX_ADC_V1_CHANNELS,
+        .mask           = ADC_S3C2410_DATX_MASK, /* 10 bit ADC resolution */
+
+        .init_hw        = exynos_adc_v1_init_hw,
+        .exit_hw        = exynos_adc_v1_exit_hw,
+        .start_conv     = exynos_adc_s3c2443_start_conv,
+};
+
 static void exynos_adc_s3c64xx_start_conv(struct exynos_adc *info,
                                           unsigned long addr)
 {
@@ -231,8 +290,18 @@ static void exynos_adc_s3c64xx_start_conv(struct exynos_adc *info,
         writel(con1 | ADC_CON_EN_START, ADC_V1_CON(info->regs));
 }
 
+static struct exynos_adc_data const exynos_adc_s3c24xx_data = {
+        .num_channels   = MAX_ADC_V1_CHANNELS,
+        .mask           = ADC_S3C2410_DATX_MASK, /* 10 bit ADC resolution */
+
+        .init_hw        = exynos_adc_v1_init_hw,
+        .exit_hw        = exynos_adc_v1_exit_hw,
+        .start_conv     = exynos_adc_s3c64xx_start_conv,
+};
+
 static struct exynos_adc_data const exynos_adc_s3c64xx_data = {
         .num_channels   = MAX_ADC_V1_CHANNELS,
+        .mask           = ADC_DATX_MASK,        /* 12 bit ADC resolution */
 
         .init_hw        = exynos_adc_v1_init_hw,
         .exit_hw        = exynos_adc_v1_exit_hw,
@@ -244,7 +313,8 @@ static void exynos_adc_v2_init_hw(struct exynos_adc *info)
 {
         u32 con1, con2;
 
-        writel(1, info->enable_reg);
+        if (info->data->needs_adc_phy)
+                writel(1, info->enable_reg);
 
         con1 = ADC_V2_CON1_SOFT_RESET;
         writel(con1, ADC_V2_CON1(info->regs));
@@ -261,7 +331,8 @@ static void exynos_adc_v2_exit_hw(struct exynos_adc *info)
 {
         u32 con;
 
-        writel(0, info->enable_reg);
+        if (info->data->needs_adc_phy)
+                writel(0, info->enable_reg);
 
         con = readl(ADC_V2_CON1(info->regs));
         con &= ~ADC_CON_EN_START;
@@ -289,6 +360,8 @@ static void exynos_adc_v2_start_conv(struct exynos_adc *info,
 
 static const struct exynos_adc_data exynos_adc_v2_data = {
         .num_channels   = MAX_ADC_V2_CHANNELS,
+        .mask           = ADC_DATX_MASK, /* 12 bit ADC resolution */
+        .needs_adc_phy  = true,
 
         .init_hw        = exynos_adc_v2_init_hw,
         .exit_hw        = exynos_adc_v2_exit_hw,
@@ -298,7 +371,9 @@ static const struct exynos_adc_data exynos_adc_v2_data = {
 
 static const struct exynos_adc_data exynos3250_adc_data = {
         .num_channels   = MAX_EXYNOS3250_ADC_CHANNELS,
+        .mask           = ADC_DATX_MASK, /* 12 bit ADC resolution */
         .needs_sclk     = true,
+        .needs_adc_phy  = true,
 
         .init_hw        = exynos_adc_v2_init_hw,
         .exit_hw        = exynos_adc_v2_exit_hw,
@@ -308,6 +383,18 @@ static const struct exynos_adc_data exynos3250_adc_data = {
 
 static const struct of_device_id exynos_adc_match[] = {
         {
+                .compatible = "samsung,s3c2410-adc",
+                .data = &exynos_adc_s3c24xx_data,
+        }, {
+                .compatible = "samsung,s3c2416-adc",
+                .data = &exynos_adc_s3c2416_data,
+        }, {
+                .compatible = "samsung,s3c2440-adc",
+                .data = &exynos_adc_s3c24xx_data,
+        }, {
+                .compatible = "samsung,s3c2443-adc",
+                .data = &exynos_adc_s3c2443_data,
+        }, {
                 .compatible = "samsung,s3c6410-adc",
                 .data = &exynos_adc_s3c64xx_data,
         }, {
@@ -373,9 +460,10 @@ static int exynos_read_raw(struct iio_dev *indio_dev,
 static irqreturn_t exynos_adc_isr(int irq, void *dev_id)
 {
         struct exynos_adc *info = (struct exynos_adc *)dev_id;
+        u32 mask = info->data->mask;
 
         /* Read value */
-        info->value = readl(ADC_V1_DATX(info->regs)) & ADC_DATX_MASK;
+        info->value = readl(ADC_V1_DATX(info->regs)) & mask;
 
         /* clear irq */
         if (info->data->clear_irq)
@@ -468,10 +556,13 @@ static int exynos_adc_probe(struct platform_device *pdev)
         if (IS_ERR(info->regs))
                 return PTR_ERR(info->regs);
 
-        mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-        info->enable_reg = devm_ioremap_resource(&pdev->dev, mem);
-        if (IS_ERR(info->enable_reg))
-                return PTR_ERR(info->enable_reg);
+
+        if (info->data->needs_adc_phy) {
+                mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+                info->enable_reg = devm_ioremap_resource(&pdev->dev, mem);
+                if (IS_ERR(info->enable_reg))
+                        return PTR_ERR(info->enable_reg);
+        }
 
         irq = platform_get_irq(pdev, 0);
         if (irq < 0) {