iio: adc: exynos_adc: Add exynos_adc_data structure to improve readability

This patchset add 'exynos_adc_data' structure which includes some functions
to control ADC operation and specific data according to ADC version (v1 or v2).

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/exynos_adc.c

@@ -39,11 +39,6 @@
 #include <linux/iio/machine.h>
 #include <linux/iio/driver.h>
 
-enum adc_version {
-	ADC_V1,
-	ADC_V2
-};
-
 /* EXYNOS4412/5250 ADC_V1 registers definitions */
 #define ADC_V1_CON(x)		((x) + 0x00)
 #define ADC_V1_DLY(x)		((x) + 0x08)
@@ -85,6 +80,7 @@ enum adc_version {
 #define EXYNOS_ADC_TIMEOUT	(msecs_to_jiffies(100))
 
 struct exynos_adc {
+	struct exynos_adc_data	*data;
 	void __iomem		*regs;
 	void __iomem		*enable_reg;
 	struct clk		*clk;
@@ -97,43 +93,139 @@ struct exynos_adc {
 	unsigned int            version;
 };
 
-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 },
-	{},
+struct exynos_adc_data {
+	int num_channels;
+
+	void (*init_hw)(struct exynos_adc *info);
+	void (*exit_hw)(struct exynos_adc *info);
+	void (*clear_irq)(struct exynos_adc *info);
+	void (*start_conv)(struct exynos_adc *info, unsigned long addr);
 };
-MODULE_DEVICE_TABLE(of, exynos_adc_match);
 
-static inline unsigned int exynos_adc_get_version(struct platform_device *pdev)
+static void exynos_adc_v1_init_hw(struct exynos_adc *info)
 {
-	const struct of_device_id *match;
+	u32 con1;
 
-	match = of_match_node(exynos_adc_match, pdev->dev.of_node);
-	return (unsigned int)match->data;
+	writel(1, info->enable_reg);
+
+	/* set default prescaler values and Enable prescaler */
+	con1 =  ADC_V1_CON_PRSCLV(49) | ADC_V1_CON_PRSCEN;
+
+	/* Enable 12-bit ADC resolution */
+	con1 |= ADC_V1_CON_RES;
+	writel(con1, ADC_V1_CON(info->regs));
+}
+
+static void exynos_adc_v1_exit_hw(struct exynos_adc *info)
+{
+	u32 con;
+
+	writel(0, info->enable_reg);
+
+	con = readl(ADC_V1_CON(info->regs));
+	con |= ADC_V1_CON_STANDBY;
+	writel(con, ADC_V1_CON(info->regs));
+}
+
+static void exynos_adc_v1_clear_irq(struct exynos_adc *info)
+{
+	writel(1, ADC_V1_INTCLR(info->regs));
 }
 
-static void exynos_adc_hw_init(struct exynos_adc *info)
+static void exynos_adc_v1_start_conv(struct exynos_adc *info,
+				     unsigned long addr)
+{
+	u32 con1;
+
+	writel(addr, ADC_V1_MUX(info->regs));
+
+	con1 = readl(ADC_V1_CON(info->regs));
+	writel(con1 | ADC_CON_EN_START, ADC_V1_CON(info->regs));
+}
+
+static const struct exynos_adc_data exynos_adc_v1_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_v1_start_conv,
+};
+
+static void exynos_adc_v2_init_hw(struct exynos_adc *info)
 {
 	u32 con1, con2;
 
-	if (info->version == ADC_V2) {
-		con1 = ADC_V2_CON1_SOFT_RESET;
-		writel(con1, ADC_V2_CON1(info->regs));
+	writel(1, info->enable_reg);
 
-		con2 = ADC_V2_CON2_OSEL | ADC_V2_CON2_ESEL |
-			ADC_V2_CON2_HIGHF | ADC_V2_CON2_C_TIME(0);
-		writel(con2, ADC_V2_CON2(info->regs));
+	con1 = ADC_V2_CON1_SOFT_RESET;
+	writel(con1, ADC_V2_CON1(info->regs));
 
-		/* Enable interrupts */
-		writel(1, ADC_V2_INT_EN(info->regs));
-	} else {
-		/* set default prescaler values and Enable prescaler */
-		con1 =  ADC_V1_CON_PRSCLV(49) | ADC_V1_CON_PRSCEN;
+	con2 = ADC_V2_CON2_OSEL | ADC_V2_CON2_ESEL |
+		ADC_V2_CON2_HIGHF | ADC_V2_CON2_C_TIME(0);
+	writel(con2, ADC_V2_CON2(info->regs));
 
-		/* Enable 12-bit ADC resolution */
-		con1 |= ADC_V1_CON_RES;
-		writel(con1, ADC_V1_CON(info->regs));
-	}
+	/* Enable interrupts */
+	writel(1, ADC_V2_INT_EN(info->regs));
+}
+
+static void exynos_adc_v2_exit_hw(struct exynos_adc *info)
+{
+	u32 con;
+
+	writel(0, info->enable_reg);
+
+	con = readl(ADC_V2_CON1(info->regs));
+	con &= ~ADC_CON_EN_START;
+	writel(con, ADC_V2_CON1(info->regs));
+}
+
+static void exynos_adc_v2_clear_irq(struct exynos_adc *info)
+{
+	writel(1, ADC_V2_INT_ST(info->regs));
+}
+
+static void exynos_adc_v2_start_conv(struct exynos_adc *info,
+				     unsigned long addr)
+{
+	u32 con1, con2;
+
+	con2 = readl(ADC_V2_CON2(info->regs));
+	con2 &= ~ADC_V2_CON2_ACH_MASK;
+	con2 |= ADC_V2_CON2_ACH_SEL(addr);
+	writel(con2, ADC_V2_CON2(info->regs));
+
+	con1 = readl(ADC_V2_CON1(info->regs));
+	writel(con1 | ADC_CON_EN_START, ADC_V2_CON1(info->regs));
+}
+
+static const struct exynos_adc_data exynos_adc_v2_data = {
+	.num_channels	= MAX_ADC_V2_CHANNELS,
+
+	.init_hw	= exynos_adc_v2_init_hw,
+	.exit_hw	= exynos_adc_v2_exit_hw,
+	.clear_irq	= exynos_adc_v2_clear_irq,
+	.start_conv	= exynos_adc_v2_start_conv,
+};
+
+static const struct of_device_id exynos_adc_match[] = {
+	{
+		.compatible = "samsung,exynos-adc-v1",
+		.data = &exynos_adc_v1_data,
+	}, {
+		.compatible = "samsung,exynos-adc-v2",
+		.data = &exynos_adc_v2_data,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, exynos_adc_match);
+
+static struct exynos_adc_data *exynos_adc_get_data(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+
+	match = of_match_node(exynos_adc_match, pdev->dev.of_node);
+	return (struct exynos_adc_data *)match->data;
 }
 
 static int exynos_read_raw(struct iio_dev *indio_dev,
@@ -144,7 +236,6 @@ static int exynos_read_raw(struct iio_dev *indio_dev,
 {
 	struct exynos_adc *info = iio_priv(indio_dev);
 	unsigned long timeout;
-	u32 con1, con2;
 	int ret;
 
 	if (mask != IIO_CHAN_INFO_RAW)
@@ -154,28 +245,15 @@ static int exynos_read_raw(struct iio_dev *indio_dev,
 	reinit_completion(&info->completion);
 
 	/* Select the channel to be used and Trigger conversion */
-	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);
-		writel(con2, ADC_V2_CON2(info->regs));
-
-		con1 = readl(ADC_V2_CON1(info->regs));
-		writel(con1 | ADC_CON_EN_START,
-				ADC_V2_CON1(info->regs));
-	} else {
-		writel(chan->address, ADC_V1_MUX(info->regs));
-
-		con1 = readl(ADC_V1_CON(info->regs));
-		writel(con1 | ADC_CON_EN_START,
-				ADC_V1_CON(info->regs));
-	}
+	if (info->data->start_conv)
+		info->data->start_conv(info, chan->address);
 
 	timeout = wait_for_completion_timeout
 			(&info->completion, EXYNOS_ADC_TIMEOUT);
 	if (timeout == 0) {
 		dev_warn(&indio_dev->dev, "Conversion timed out! Resetting\n");
-		exynos_adc_hw_init(info);
+		if (info->data->init_hw)
+			info->data->init_hw(info);
 		ret = -ETIMEDOUT;
 	} else {
 		*val = info->value;
@@ -193,13 +271,11 @@ static irqreturn_t exynos_adc_isr(int irq, void *dev_id)
 	struct exynos_adc *info = (struct exynos_adc *)dev_id;
 
 	/* Read value */
-	info->value = readl(ADC_V1_DATX(info->regs)) &
-						ADC_DATX_MASK;
+	info->value = readl(ADC_V1_DATX(info->regs)) & ADC_DATX_MASK;
+
 	/* clear irq */
-	if (info->version == ADC_V2)
-		writel(1, ADC_V2_INT_ST(info->regs));
-	else
-		writel(1, ADC_V1_INTCLR(info->regs));
+	if (info->data->clear_irq)
+		info->data->clear_irq(info);
 
 	complete(&info->completion);
 
@@ -277,6 +353,12 @@ static int exynos_adc_probe(struct platform_device *pdev)
 
 	info = iio_priv(indio_dev);
 
+	info->data = exynos_adc_get_data(pdev);
+	if (!info->data) {
+		dev_err(&pdev->dev, "failed getting exynos_adc_data\n");
+		return -EINVAL;
+	}
+
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	info->regs = devm_ioremap_resource(&pdev->dev, mem);
 	if (IS_ERR(info->regs))
@@ -319,10 +401,6 @@ static int exynos_adc_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_disable_reg;
 
-	writel(1, info->enable_reg);
-
-	info->version = exynos_adc_get_version(pdev);
-
 	platform_set_drvdata(pdev, indio_dev);
 
 	indio_dev->name = dev_name(&pdev->dev);
@@ -331,11 +409,7 @@ static int exynos_adc_probe(struct platform_device *pdev)
 	indio_dev->info = &exynos_adc_iio_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = exynos_adc_iio_channels;
-
-	if (info->version == ADC_V1)
-		indio_dev->num_channels = MAX_ADC_V1_CHANNELS;
-	else
-		indio_dev->num_channels = MAX_ADC_V2_CHANNELS;
+	indio_dev->num_channels = info->data->num_channels;
 
 	ret = request_irq(info->irq, exynos_adc_isr,
 					0, dev_name(&pdev->dev), info);
@@ -349,7 +423,8 @@ static int exynos_adc_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_irq;
 
-	exynos_adc_hw_init(info);
+	if (info->data->init_hw)
+		info->data->init_hw(info);
 
 	ret = of_platform_populate(np, exynos_adc_match, NULL, &indio_dev->dev);
 	if (ret < 0) {
@@ -366,7 +441,8 @@ err_of_populate:
 err_irq:
 	free_irq(info->irq, info);
 err_disable_clk:
-	writel(0, info->enable_reg);
+	if (info->data->exit_hw)
+		info->data->exit_hw(info);
 	clk_disable_unprepare(info->clk);
 err_disable_reg:
 	regulator_disable(info->vdd);
@@ -382,7 +458,8 @@ static int exynos_adc_remove(struct platform_device *pdev)
 				exynos_adc_remove_devices);
 	iio_device_unregister(indio_dev);
 	free_irq(info->irq, info);
-	writel(0, info->enable_reg);
+	if (info->data->exit_hw)
+		info->data->exit_hw(info);
 	clk_disable_unprepare(info->clk);
 	regulator_disable(info->vdd);
 
@@ -394,19 +471,10 @@ static int exynos_adc_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct exynos_adc *info = iio_priv(indio_dev);
-	u32 con;
 
-	if (info->version == ADC_V2) {
-		con = readl(ADC_V2_CON1(info->regs));
-		con &= ~ADC_CON_EN_START;
-		writel(con, ADC_V2_CON1(info->regs));
-	} else {
-		con = readl(ADC_V1_CON(info->regs));
-		con |= ADC_V1_CON_STANDBY;
-		writel(con, ADC_V1_CON(info->regs));
-	}
+	if (info->data->exit_hw)
+		info->data->exit_hw(info);
 
-	writel(0, info->enable_reg);
 	clk_disable_unprepare(info->clk);
 	regulator_disable(info->vdd);
 
@@ -427,8 +495,8 @@ static int exynos_adc_resume(struct device *dev)
 	if (ret)
 		return ret;
 
-	writel(1, info->enable_reg);
-	exynos_adc_hw_init(info);
+	if (info->data->init_hw)
+		info->data->init_hw(info);
 
 	return 0;
 }