1 files changed, 248 insertions, 21 deletions

diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c
index 22b7c9321e78..e09233b03c05 100644
--- a/drivers/iio/adc/stm32-adc-core.c
+++ b/drivers/iio/adc/stm32-adc-core.c
@@ -49,19 +49,66 @@
 /* STM32 F4 maximum analog clock rate (from datasheet) */
 #define STM32F4_ADC_MAX_CLK_RATE	36000000
 
+/* STM32H7 - common registers for all ADC instances */
+#define STM32H7_ADC_CSR			(STM32_ADCX_COMN_OFFSET + 0x00)
+#define STM32H7_ADC_CCR			(STM32_ADCX_COMN_OFFSET + 0x08)
+
+/* STM32H7_ADC_CSR - bit fields */
+#define STM32H7_EOC_SLV			BIT(18)
+#define STM32H7_EOC_MST			BIT(2)
+
+/* STM32H7_ADC_CCR - bit fields */
+#define STM32H7_PRESC_SHIFT		18
+#define STM32H7_PRESC_MASK		GENMASK(21, 18)
+#define STM32H7_CKMODE_SHIFT		16
+#define STM32H7_CKMODE_MASK		GENMASK(17, 16)
+
+/* STM32 H7 maximum analog clock rate (from datasheet) */
+#define STM32H7_ADC_MAX_CLK_RATE	72000000
+
+/**
+ * stm32_adc_common_regs - stm32 common registers, compatible dependent data
+ * @csr:	common status register offset
+ * @eoc1:	adc1 end of conversion flag in @csr
+ * @eoc2:	adc2 end of conversion flag in @csr
+ * @eoc3:	adc3 end of conversion flag in @csr
+ */
+struct stm32_adc_common_regs {
+	u32 csr;
+	u32 eoc1_msk;
+	u32 eoc2_msk;
+	u32 eoc3_msk;
+};
+
+struct stm32_adc_priv;
+
+/**
+ * stm32_adc_priv_cfg - stm32 core compatible configuration data
+ * @regs:	common registers for all instances
+ * @clk_sel:	clock selection routine
+ */
+struct stm32_adc_priv_cfg {
+	const struct stm32_adc_common_regs *regs;
+	int (*clk_sel)(struct platform_device *, struct stm32_adc_priv *);
+};
+
 /**
  * struct stm32_adc_priv - stm32 ADC core private data
  * @irq:		irq for ADC block
  * @domain:		irq domain reference
  * @aclk:		clock reference for the analog circuitry
+ * @bclk:		bus clock common for all ADCs, depends on part used
  * @vref:		regulator reference
+ * @cfg:		compatible configuration data
  * @common:		common data for all ADC instances
  */
 struct stm32_adc_priv {
 	int				irq;
 	struct irq_domain		*domain;
 	struct clk			*aclk;
+	struct clk			*bclk;
 	struct regulator		*vref;
+	const struct stm32_adc_priv_cfg	*cfg;
 	struct stm32_adc_common		common;
 };
 
@@ -85,14 +132,23 @@ static int stm32f4_adc_clk_sel(struct platform_device *pdev,
 	u32 val;
 	int i;
 
+	/* stm32f4 has one clk input for analog (mandatory), enforce it here */
+	if (!priv->aclk) {
+		dev_err(&pdev->dev, "No 'adc' clock found\n");
+		return -ENOENT;
+	}
+
 	rate = clk_get_rate(priv->aclk);
 	for (i = 0; i < ARRAY_SIZE(stm32f4_pclk_div); i++) {
 		if ((rate / stm32f4_pclk_div[i]) <= STM32F4_ADC_MAX_CLK_RATE)
 			break;
 	}
-	if (i >= ARRAY_SIZE(stm32f4_pclk_div))
+	if (i >= ARRAY_SIZE(stm32f4_pclk_div)) {
+		dev_err(&pdev->dev, "adc clk selection failed\n");
 		return -EINVAL;
+	}
 
+	priv->common.rate = rate;
 	val = readl_relaxed(priv->common.base + STM32F4_ADC_CCR);
 	val &= ~STM32F4_ADC_ADCPRE_MASK;
 	val |= i << STM32F4_ADC_ADCPRE_SHIFT;
@@ -104,6 +160,126 @@ static int stm32f4_adc_clk_sel(struct platform_device *pdev,
 	return 0;
 }
 
+/**
+ * struct stm32h7_adc_ck_spec - specification for stm32h7 adc clock
+ * @ckmode: ADC clock mode, Async or sync with prescaler.
+ * @presc: prescaler bitfield for async clock mode
+ * @div: prescaler division ratio
+ */
+struct stm32h7_adc_ck_spec {
+	u32 ckmode;
+	u32 presc;
+	int div;
+};
+
+const struct stm32h7_adc_ck_spec stm32h7_adc_ckmodes_spec[] = {
+	/* 00: CK_ADC[1..3]: Asynchronous clock modes */
+	{ 0, 0, 1 },
+	{ 0, 1, 2 },
+	{ 0, 2, 4 },
+	{ 0, 3, 6 },
+	{ 0, 4, 8 },
+	{ 0, 5, 10 },
+	{ 0, 6, 12 },
+	{ 0, 7, 16 },
+	{ 0, 8, 32 },
+	{ 0, 9, 64 },
+	{ 0, 10, 128 },
+	{ 0, 11, 256 },
+	/* HCLK used: Synchronous clock modes (1, 2 or 4 prescaler) */
+	{ 1, 0, 1 },
+	{ 2, 0, 2 },
+	{ 3, 0, 4 },
+};
+
+static int stm32h7_adc_clk_sel(struct platform_device *pdev,
+			       struct stm32_adc_priv *priv)
+{
+	u32 ckmode, presc, val;
+	unsigned long rate;
+	int i, div;
+
+	/* stm32h7 bus clock is common for all ADC instances (mandatory) */
+	if (!priv->bclk) {
+		dev_err(&pdev->dev, "No 'bus' clock found\n");
+		return -ENOENT;
+	}
+
+	/*
+	 * stm32h7 can use either 'bus' or 'adc' clock for analog circuitry.
+	 * So, choice is to have bus clock mandatory and adc clock optional.
+	 * If optional 'adc' clock has been found, then try to use it first.
+	 */
+	if (priv->aclk) {
+		/*
+		 * Asynchronous clock modes (e.g. ckmode == 0)
+		 * From spec: PLL output musn't exceed max rate
+		 */
+		rate = clk_get_rate(priv->aclk);
+
+		for (i = 0; i < ARRAY_SIZE(stm32h7_adc_ckmodes_spec); i++) {
+			ckmode = stm32h7_adc_ckmodes_spec[i].ckmode;
+			presc = stm32h7_adc_ckmodes_spec[i].presc;
+			div = stm32h7_adc_ckmodes_spec[i].div;
+
+			if (ckmode)
+				continue;
+
+			if ((rate / div) <= STM32H7_ADC_MAX_CLK_RATE)
+				goto out;
+		}
+	}
+
+	/* Synchronous clock modes (e.g. ckmode is 1, 2 or 3) */
+	rate = clk_get_rate(priv->bclk);
+
+	for (i = 0; i < ARRAY_SIZE(stm32h7_adc_ckmodes_spec); i++) {
+		ckmode = stm32h7_adc_ckmodes_spec[i].ckmode;
+		presc = stm32h7_adc_ckmodes_spec[i].presc;
+		div = stm32h7_adc_ckmodes_spec[i].div;
+
+		if (!ckmode)
+			continue;
+
+		if ((rate / div) <= STM32H7_ADC_MAX_CLK_RATE)
+			goto out;
+	}
+
+	dev_err(&pdev->dev, "adc clk selection failed\n");
+	return -EINVAL;
+
+out:
+	/* rate used later by each ADC instance to control BOOST mode */
+	priv->common.rate = rate;
+
+	/* Set common clock mode and prescaler */
+	val = readl_relaxed(priv->common.base + STM32H7_ADC_CCR);
+	val &= ~(STM32H7_CKMODE_MASK | STM32H7_PRESC_MASK);
+	val |= ckmode << STM32H7_CKMODE_SHIFT;
+	val |= presc << STM32H7_PRESC_SHIFT;
+	writel_relaxed(val, priv->common.base + STM32H7_ADC_CCR);
+
+	dev_dbg(&pdev->dev, "Using %s clock/%d source at %ld kHz\n",
+		ckmode ? "bus" : "adc", div, rate / (div * 1000));
+
+	return 0;
+}
+
+/* STM32F4 common registers definitions */
+static const struct stm32_adc_common_regs stm32f4_adc_common_regs = {
+	.csr = STM32F4_ADC_CSR,
+	.eoc1_msk = STM32F4_EOC1,
+	.eoc2_msk = STM32F4_EOC2,
+	.eoc3_msk = STM32F4_EOC3,
+};
+
+/* STM32H7 common registers definitions */
+static const struct stm32_adc_common_regs stm32h7_adc_common_regs = {
+	.csr = STM32H7_ADC_CSR,
+	.eoc1_msk = STM32H7_EOC_MST,
+	.eoc2_msk = STM32H7_EOC_SLV,
+};
+
 /* ADC common interrupt for all instances */
 static void stm32_adc_irq_handler(struct irq_desc *desc)
 {
@@ -112,15 +288,15 @@ static void stm32_adc_irq_handler(struct irq_desc *desc)
 	u32 status;
 
 	chained_irq_enter(chip, desc);
-	status = readl_relaxed(priv->common.base + STM32F4_ADC_CSR);
+	status = readl_relaxed(priv->common.base + priv->cfg->regs->csr);
 
-	if (status & STM32F4_EOC1)
+	if (status & priv->cfg->regs->eoc1_msk)
 		generic_handle_irq(irq_find_mapping(priv->domain, 0));
 
-	if (status & STM32F4_EOC2)
+	if (status & priv->cfg->regs->eoc2_msk)
 		generic_handle_irq(irq_find_mapping(priv->domain, 1));
 
-	if (status & STM32F4_EOC3)
+	if (status & priv->cfg->regs->eoc3_msk)
 		generic_handle_irq(irq_find_mapping(priv->domain, 2));
 
 	chained_irq_exit(chip, desc);
@@ -186,6 +362,7 @@ static void stm32_adc_irq_remove(struct platform_device *pdev,
 static int stm32_adc_probe(struct platform_device *pdev)
 {
 	struct stm32_adc_priv *priv;
+	struct device *dev = &pdev->dev;
 	struct device_node *np = pdev->dev.of_node;
 	struct resource *res;
 	int ret;
@@ -197,6 +374,9 @@ static int stm32_adc_probe(struct platform_device *pdev)
 	if (!priv)
 		return -ENOMEM;
 
+	priv->cfg = (const struct stm32_adc_priv_cfg *)
+		of_match_device(dev->driver->of_match_table, dev)->data;
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	priv->common.base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(priv->common.base))
@@ -227,25 +407,48 @@ static int stm32_adc_probe(struct platform_device *pdev)
 	priv->aclk = devm_clk_get(&pdev->dev, "adc");
 	if (IS_ERR(priv->aclk)) {
 		ret = PTR_ERR(priv->aclk);
-		dev_err(&pdev->dev, "Can't get 'adc' clock\n");
-		goto err_regulator_disable;
+		if (ret == -ENOENT) {
+			priv->aclk = NULL;
+		} else {
+			dev_err(&pdev->dev, "Can't get 'adc' clock\n");
+			goto err_regulator_disable;
+		}
 	}
 
-	ret = clk_prepare_enable(priv->aclk);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "adc clk enable failed\n");
-		goto err_regulator_disable;
+	if (priv->aclk) {
+		ret = clk_prepare_enable(priv->aclk);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "adc clk enable failed\n");
+			goto err_regulator_disable;
+		}
 	}
 
-	ret = stm32f4_adc_clk_sel(pdev, priv);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "adc clk selection failed\n");
-		goto err_clk_disable;
+	priv->bclk = devm_clk_get(&pdev->dev, "bus");
+	if (IS_ERR(priv->bclk)) {
+		ret = PTR_ERR(priv->bclk);
+		if (ret == -ENOENT) {
+			priv->bclk = NULL;
+		} else {
+			dev_err(&pdev->dev, "Can't get 'bus' clock\n");
+			goto err_aclk_disable;
+		}
+	}
+
+	if (priv->bclk) {
+		ret = clk_prepare_enable(priv->bclk);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "adc clk enable failed\n");
+			goto err_aclk_disable;
+		}
 	}
 
+	ret = priv->cfg->clk_sel(pdev, priv);
+	if (ret < 0)
+		goto err_bclk_disable;
+
 	ret = stm32_adc_irq_probe(pdev, priv);
 	if (ret < 0)
-		goto err_clk_disable;
+		goto err_bclk_disable;
 
 	platform_set_drvdata(pdev, &priv->common);
 
@@ -260,8 +463,13 @@ static int stm32_adc_probe(struct platform_device *pdev)
 err_irq_remove:
 	stm32_adc_irq_remove(pdev, priv);
 
-err_clk_disable:
-	clk_disable_unprepare(priv->aclk);
+err_bclk_disable:
+	if (priv->bclk)
+		clk_disable_unprepare(priv->bclk);
+
+err_aclk_disable:
+	if (priv->aclk)
+		clk_disable_unprepare(priv->aclk);
 
 err_regulator_disable:
 	regulator_disable(priv->vref);
@@ -276,15 +484,34 @@ static int stm32_adc_remove(struct platform_device *pdev)
 
 	of_platform_depopulate(&pdev->dev);
 	stm32_adc_irq_remove(pdev, priv);
-	clk_disable_unprepare(priv->aclk);
+	if (priv->bclk)
+		clk_disable_unprepare(priv->bclk);
+	if (priv->aclk)
+		clk_disable_unprepare(priv->aclk);
 	regulator_disable(priv->vref);
 
 	return 0;
 }
 
+static const struct stm32_adc_priv_cfg stm32f4_adc_priv_cfg = {
+	.regs = &stm32f4_adc_common_regs,
+	.clk_sel = stm32f4_adc_clk_sel,
+};
+
+static const struct stm32_adc_priv_cfg stm32h7_adc_priv_cfg = {
+	.regs = &stm32h7_adc_common_regs,
+	.clk_sel = stm32h7_adc_clk_sel,
+};
+
 static const struct of_device_id stm32_adc_of_match[] = {
-	{ .compatible = "st,stm32f4-adc-core" },
-	{},
+	{
+		.compatible = "st,stm32f4-adc-core",
+		.data = (void *)&stm32f4_adc_priv_cfg
+	}, {
+		.compatible = "st,stm32h7-adc-core",
+		.data = (void *)&stm32h7_adc_priv_cfg
+	}, {
+	},
 };
 MODULE_DEVICE_TABLE(of, stm32_adc_of_match);