diff options
Diffstat (limited to 'drivers/iio/adc/stm32-adc-core.c')
-rw-r--r-- | drivers/iio/adc/stm32-adc-core.c | 97 |
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; |