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path: root/drivers/iio/adc/stm32-adc-core.c
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Diffstat (limited to 'drivers/iio/adc/stm32-adc-core.c')
-rw-r--r--drivers/iio/adc/stm32-adc-core.c97
1 files changed, 59 insertions, 38 deletions
diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c
index 9b85fefc0a96..6537f4f776c5 100644
--- a/drivers/iio/adc/stm32-adc-core.c
+++ b/drivers/iio/adc/stm32-adc-core.c
@@ -24,33 +24,6 @@
#include "stm32-adc-core.h"
-/* STM32F4 - common registers for all ADC instances: 1, 2 & 3 */
-#define STM32F4_ADC_CSR (STM32_ADCX_COMN_OFFSET + 0x00)
-#define STM32F4_ADC_CCR (STM32_ADCX_COMN_OFFSET + 0x04)
-
-/* STM32F4_ADC_CSR - bit fields */
-#define STM32F4_EOC3 BIT(17)
-#define STM32F4_EOC2 BIT(9)
-#define STM32F4_EOC1 BIT(1)
-
-/* STM32F4_ADC_CCR - bit fields */
-#define STM32F4_ADC_ADCPRE_SHIFT 16
-#define STM32F4_ADC_ADCPRE_MASK GENMASK(17, 16)
-
-/* 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)
-
#define STM32_ADC_CORE_SLEEP_DELAY_MS 2000
/* SYSCFG registers */
@@ -65,12 +38,14 @@
#define HAS_ANASWVDD BIT(1)
/**
- * stm32_adc_common_regs - stm32 common registers, compatible dependent data
+ * struct stm32_adc_common_regs - stm32 common registers
* @csr: common status register offset
* @ccr: common control 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
+ * @eoc1_msk: adc1 end of conversion flag in @csr
+ * @eoc2_msk: adc2 end of conversion flag in @csr
+ * @eoc3_msk: adc3 end of conversion flag in @csr
+ * @ier: interrupt enable register offset for each adc
+ * @eocie_msk: end of conversion interrupt enable mask in @ier
*/
struct stm32_adc_common_regs {
u32 csr;
@@ -78,12 +53,14 @@ struct stm32_adc_common_regs {
u32 eoc1_msk;
u32 eoc2_msk;
u32 eoc3_msk;
+ u32 ier;
+ u32 eocie_msk;
};
struct stm32_adc_priv;
/**
- * stm32_adc_priv_cfg - stm32 core compatible configuration data
+ * struct stm32_adc_priv_cfg - stm32 core compatible configuration data
* @regs: common registers for all instances
* @clk_sel: clock selection routine
* @max_clk_rate_hz: maximum analog clock rate (Hz, from datasheet)
@@ -102,6 +79,7 @@ struct stm32_adc_priv_cfg {
* @domain: irq domain reference
* @aclk: clock reference for the analog circuitry
* @bclk: bus clock common for all ADCs, depends on part used
+ * @max_clk_rate: desired maximum clock rate
* @booster: booster supply reference
* @vdd: vdd supply reference
* @vdda: vdda analog supply reference
@@ -118,6 +96,7 @@ struct stm32_adc_priv {
struct irq_domain *domain;
struct clk *aclk;
struct clk *bclk;
+ u32 max_clk_rate;
struct regulator *booster;
struct regulator *vdd;
struct regulator *vdda;
@@ -140,6 +119,7 @@ static int stm32f4_pclk_div[] = {2, 4, 6, 8};
/**
* stm32f4_adc_clk_sel() - Select stm32f4 ADC common clock prescaler
+ * @pdev: platform device
* @priv: stm32 ADC core private data
* Select clock prescaler used for analog conversions, before using ADC.
*/
@@ -163,7 +143,7 @@ static int stm32f4_adc_clk_sel(struct platform_device *pdev,
}
for (i = 0; i < ARRAY_SIZE(stm32f4_pclk_div); i++) {
- if ((rate / stm32f4_pclk_div[i]) <= priv->cfg->max_clk_rate_hz)
+ if ((rate / stm32f4_pclk_div[i]) <= priv->max_clk_rate)
break;
}
if (i >= ARRAY_SIZE(stm32f4_pclk_div)) {
@@ -252,7 +232,7 @@ static int stm32h7_adc_clk_sel(struct platform_device *pdev,
if (ckmode)
continue;
- if ((rate / div) <= priv->cfg->max_clk_rate_hz)
+ if ((rate / div) <= priv->max_clk_rate)
goto out;
}
}
@@ -272,7 +252,7 @@ static int stm32h7_adc_clk_sel(struct platform_device *pdev,
if (!ckmode)
continue;
- if ((rate / div) <= priv->cfg->max_clk_rate_hz)
+ if ((rate / div) <= priv->max_clk_rate)
goto out;
}
@@ -303,6 +283,8 @@ static const struct stm32_adc_common_regs stm32f4_adc_common_regs = {
.eoc1_msk = STM32F4_EOC1,
.eoc2_msk = STM32F4_EOC2,
.eoc3_msk = STM32F4_EOC3,
+ .ier = STM32F4_ADC_CR1,
+ .eocie_msk = STM32F4_EOCIE,
};
/* STM32H7 common registers definitions */
@@ -311,8 +293,24 @@ static const struct stm32_adc_common_regs stm32h7_adc_common_regs = {
.ccr = STM32H7_ADC_CCR,
.eoc1_msk = STM32H7_EOC_MST,
.eoc2_msk = STM32H7_EOC_SLV,
+ .ier = STM32H7_ADC_IER,
+ .eocie_msk = STM32H7_EOCIE,
+};
+
+static const unsigned int stm32_adc_offset[STM32_ADC_MAX_ADCS] = {
+ 0, STM32_ADC_OFFSET, STM32_ADC_OFFSET * 2,
};
+static unsigned int stm32_adc_eoc_enabled(struct stm32_adc_priv *priv,
+ unsigned int adc)
+{
+ u32 ier, offset = stm32_adc_offset[adc];
+
+ ier = readl_relaxed(priv->common.base + offset + priv->cfg->regs->ier);
+
+ return ier & priv->cfg->regs->eocie_msk;
+}
+
/* ADC common interrupt for all instances */
static void stm32_adc_irq_handler(struct irq_desc *desc)
{
@@ -323,13 +321,28 @@ static void stm32_adc_irq_handler(struct irq_desc *desc)
chained_irq_enter(chip, desc);
status = readl_relaxed(priv->common.base + priv->cfg->regs->csr);
- if (status & priv->cfg->regs->eoc1_msk)
+ /*
+ * End of conversion may be handled by using IRQ or DMA. There may be a
+ * race here when two conversions complete at the same time on several
+ * ADCs. EOC may be read 'set' for several ADCs, with:
+ * - an ADC configured to use DMA (EOC triggers the DMA request, and
+ * is then automatically cleared by DR read in hardware)
+ * - an ADC configured to use IRQs (EOCIE bit is set. The handler must
+ * be called in this case)
+ * So both EOC status bit in CSR and EOCIE control bit must be checked
+ * before invoking the interrupt handler (e.g. call ISR only for
+ * IRQ-enabled ADCs).
+ */
+ if (status & priv->cfg->regs->eoc1_msk &&
+ stm32_adc_eoc_enabled(priv, 0))
generic_handle_irq(irq_find_mapping(priv->domain, 0));
- if (status & priv->cfg->regs->eoc2_msk)
+ if (status & priv->cfg->regs->eoc2_msk &&
+ stm32_adc_eoc_enabled(priv, 1))
generic_handle_irq(irq_find_mapping(priv->domain, 1));
- if (status & priv->cfg->regs->eoc3_msk)
+ if (status & priv->cfg->regs->eoc3_msk &&
+ stm32_adc_eoc_enabled(priv, 2))
generic_handle_irq(irq_find_mapping(priv->domain, 2));
chained_irq_exit(chip, desc);
@@ -644,6 +657,7 @@ static int stm32_adc_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct device_node *np = pdev->dev.of_node;
struct resource *res;
+ u32 max_rate;
int ret;
if (!pdev->dev.of_node)
@@ -720,6 +734,13 @@ static int stm32_adc_probe(struct platform_device *pdev)
priv->common.vref_mv = ret / 1000;
dev_dbg(&pdev->dev, "vref+=%dmV\n", priv->common.vref_mv);
+ ret = of_property_read_u32(pdev->dev.of_node, "st,max-clk-rate-hz",
+ &max_rate);
+ if (!ret)
+ priv->max_clk_rate = min(max_rate, priv->cfg->max_clk_rate_hz);
+ else
+ priv->max_clk_rate = priv->cfg->max_clk_rate_hz;
+
ret = priv->cfg->clk_sel(pdev, priv);
if (ret < 0)
goto err_hw_stop;