[PATCHv2 1/2] iio: adc: exynos_adc: Control special clock of ADC to support Exynos3250 ADC

[Chanwoo Choi]

This patch control special clock for ADC in Exynos series's FSYS block.
If special clock of ADC is registerd on clock list of common clk framework,
Exynos ADC drvier have to control this clock.

Exynos3250/Exynos4/Exynos5 has 'adc' clock as following:
- 'adc' clock: bus clock for ADC

Exynos3250 has additional 'sclk_tsadc' clock as following:
- 'sclk_tsadc' clock: special clock for ADC which provide clock to internal ADC

Exynos 4210/4212/4412 and Exynos5250/5420 has not included 'sclk_tsadc' clock
in FSYS_BLK. But, Exynos3250 based on Cortex-A7 has only included 'sclk_tsadc'
clock in FSYS_BLK.

Cc: Jonathan Cameron <jic23 at kernel.org>
Cc: Kukjin Kim <kgene.kim at samsung.com>
Cc: Naveen Krishna Chatradhi
Cc: linux-iio at vger.kernel.org
Signed-off-by: Chanwoo Choi <cw00.choi at samsung.com>
Acked-by: Kyungmin Park <kyungmin.park at samsung.com>
---
 drivers/iio/adc/exynos_adc.c | 54 +++++++++++++++++++++++++++++++++-----------
 1 file changed, 41 insertions(+), 13 deletions(-)

diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
index d25b262..3c99243 100644
--- a/drivers/iio/adc/exynos_adc.c
+++ b/drivers/iio/adc/exynos_adc.c
@@ -40,8 +40,9 @@
 #include <linux/iio/driver.h>
 
 enum adc_version {
-	ADC_V1,
-	ADC_V2
+	ADC_V1 = 0x1,
+	ADC_V2 = 0x2,
+	ADC_V3 = (ADC_V1 | ADC_V2),
 };
 
 /* EXYNOS4412/5250 ADC_V1 registers definitions */
@@ -88,6 +89,7 @@ struct exynos_adc {
 	void __iomem		*regs;
 	void __iomem		*enable_reg;
 	struct clk		*clk;
+	struct clk		*sclk;
 	unsigned int		irq;
 	struct regulator	*vdd;
 
@@ -100,6 +102,7 @@ struct exynos_adc {
 static const struct of_device_id exynos_adc_match[] = {
 	{ .compatible = "samsung,exynos-adc-v1", .data = (void *)ADC_V1 },
 	{ .compatible = "samsung,exynos-adc-v2", .data = (void *)ADC_V2 },
+	{ .compatible = "samsung,exynos-adc-v3", .data = (void *)ADC_V3 },
 	{},
 };
 MODULE_DEVICE_TABLE(of, exynos_adc_match);
@@ -128,7 +131,7 @@ static int exynos_read_raw(struct iio_dev *indio_dev,
 	mutex_lock(&indio_dev->mlock);
 
 	/* Select the channel to be used and Trigger conversion */
-	if (info->version == ADC_V2) {
+	if (info->version & ADC_V2) {
 		con2 = readl(ADC_V2_CON2(info->regs));
 		con2 &= ~ADC_V2_CON2_ACH_MASK;
 		con2 |= ADC_V2_CON2_ACH_SEL(chan->address);
@@ -165,7 +168,7 @@ static irqreturn_t exynos_adc_isr(int irq, void *dev_id)
 	info->value = readl(ADC_V1_DATX(info->regs)) &
 						ADC_DATX_MASK;
 	/* clear irq */
-	if (info->version == ADC_V2)
+	if (info->version & ADC_V2)
 		writel(1, ADC_V2_INT_ST(info->regs));
 	else
 		writel(1, ADC_V1_INTCLR(info->regs));
@@ -226,11 +229,25 @@ static int exynos_adc_remove_devices(struct device *dev, void *c)
 	return 0;
 }
 
+static void exynos_adc_enable_clock(struct exynos_adc *info, bool enable)
+{
+	if (enable) {
+		clk_prepare_enable(info->clk);
+		if (info->version == ADC_V3)
+			clk_prepare_enable(info->sclk);
+
+	} else {
+		if (info->version == ADC_V3)
+			clk_disable_unprepare(info->sclk);
+		clk_disable_unprepare(info->clk);
+	}
+}
+
 static void exynos_adc_hw_init(struct exynos_adc *info)
 {
 	u32 con1, con2;
 
-	if (info->version == ADC_V2) {
+	if (info->version & ADC_V2) {
 		con1 = ADC_V2_CON1_SOFT_RESET;
 		writel(con1, ADC_V2_CON1(info->regs));
 
@@ -300,6 +317,8 @@ static int exynos_adc_probe(struct platform_device *pdev)
 
 	writel(1, info->enable_reg);
 
+	info->version = exynos_adc_get_version(pdev);
+
 	info->clk = devm_clk_get(&pdev->dev, "adc");
 	if (IS_ERR(info->clk)) {
 		dev_err(&pdev->dev, "failed getting clock, err = %ld\n",
@@ -308,6 +327,17 @@ static int exynos_adc_probe(struct platform_device *pdev)
 		goto err_irq;
 	}
 
+	if (info->version == ADC_V3) {
+		info->sclk = devm_clk_get(&pdev->dev, "sclk_tsadc");
+		if (IS_ERR(info->sclk)) {
+			dev_warn(&pdev->dev,
+				"failed getting sclk clock, err = %ld\n",
+				PTR_ERR(info->sclk));
+			ret = PTR_ERR(info->sclk);
+			goto err_irq;
+		}
+	}
+
 	info->vdd = devm_regulator_get(&pdev->dev, "vdd");
 	if (IS_ERR(info->vdd)) {
 		dev_err(&pdev->dev, "failed getting regulator, err = %ld\n",
@@ -316,8 +346,6 @@ static int exynos_adc_probe(struct platform_device *pdev)
 		goto err_irq;
 	}
 
-	info->version = exynos_adc_get_version(pdev);
-
 	platform_set_drvdata(pdev, indio_dev);
 
 	indio_dev->name = dev_name(&pdev->dev);
@@ -340,7 +368,7 @@ static int exynos_adc_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_iio_dev;
 
-	clk_prepare_enable(info->clk);
+	exynos_adc_enable_clock(info, true);
 
 	exynos_adc_hw_init(info);
 
@@ -356,7 +384,7 @@ err_of_populate:
 	device_for_each_child(&pdev->dev, NULL,
 				exynos_adc_remove_devices);
 	regulator_disable(info->vdd);
-	clk_disable_unprepare(info->clk);
+	exynos_adc_enable_clock(info, false);
 err_iio_dev:
 	iio_device_unregister(indio_dev);
 err_irq:
@@ -372,7 +400,7 @@ static int exynos_adc_remove(struct platform_device *pdev)
 	device_for_each_child(&pdev->dev, NULL,
 				exynos_adc_remove_devices);
 	regulator_disable(info->vdd);
-	clk_disable_unprepare(info->clk);
+	exynos_adc_enable_clock(info, false);
 	writel(0, info->enable_reg);
 	iio_device_unregister(indio_dev);
 	free_irq(info->irq, info);
@@ -387,7 +415,7 @@ static int exynos_adc_suspend(struct device *dev)
 	struct exynos_adc *info = iio_priv(indio_dev);
 	u32 con;
 
-	if (info->version == ADC_V2) {
+	if (info->version & ADC_V2) {
 		con = readl(ADC_V2_CON1(info->regs));
 		con &= ~ADC_CON_EN_START;
 		writel(con, ADC_V2_CON1(info->regs));
@@ -397,7 +425,7 @@ static int exynos_adc_suspend(struct device *dev)
 		writel(con, ADC_V1_CON(info->regs));
 	}
 
-	clk_disable_unprepare(info->clk);
+	exynos_adc_enable_clock(info, false);
 	writel(0, info->enable_reg);
 	regulator_disable(info->vdd);
 
@@ -415,7 +443,7 @@ static int exynos_adc_resume(struct device *dev)
 		return ret;
 
 	writel(1, info->enable_reg);
-	clk_prepare_enable(info->clk);
+	exynos_adc_enable_clock(info, true);
 
 	exynos_adc_hw_init(info);
 
-- 
1.8.0