From 31922f62bb527d749b99dbc776e514bcba29b7fe Mon Sep 17 00:00:00 2001 From: Fabrice Gasnier Date: Tue, 17 Sep 2019 14:38:15 +0200 Subject: iio: adc: stm32-adc: move registers definitions Move STM32 ADC registers definitions to common header. This is precursor patch to: - iio: adc: stm32-adc: fix a race when using several adcs with dma and irq It keeps registers definitions as a whole block, to ease readability and allow simple access path to EOC bits (readl) in stm32-adc-core driver. Fixes: 2763ea0585c9 ("iio: adc: stm32: add optional dma support") Signed-off-by: Fabrice Gasnier Cc: Signed-off-by: Jonathan Cameron --- drivers/iio/adc/stm32-adc-core.c | 27 --------------------------- 1 file changed, 27 deletions(-) (limited to 'drivers/iio/adc/stm32-adc-core.c') diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c index 9b85fefc0a96..84ac326bb714 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 */ -- cgit v1.2.3 From dcb10920179ab74caf88a6f2afadecfc2743b910 Mon Sep 17 00:00:00 2001 From: Fabrice Gasnier Date: Tue, 17 Sep 2019 14:38:16 +0200 Subject: iio: adc: stm32-adc: fix a race when using several adcs with dma and irq End of conversion may be handled by using IRQ or DMA. There may be a race when two conversions complete at the same time on several ADCs. EOC can be read as 'set' for several ADCs, with: - an ADC configured to use IRQs. EOCIE bit is set. The handler is normally called in this case. - an ADC configured to use DMA. EOCIE bit isn't set. EOC triggers the DMA request instead. It's then automatically cleared by DMA read. But the handler gets called due to status bit is temporarily set (IRQ triggered by the other ADC). 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). Fixes: 2763ea0585c9 ("iio: adc: stm32: add optional dma support") Signed-off-by: Fabrice Gasnier Cc: Signed-off-by: Jonathan Cameron --- drivers/iio/adc/stm32-adc-core.c | 43 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 40 insertions(+), 3 deletions(-) (limited to 'drivers/iio/adc/stm32-adc-core.c') diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c index 84ac326bb714..93a096a91f8c 100644 --- a/drivers/iio/adc/stm32-adc-core.c +++ b/drivers/iio/adc/stm32-adc-core.c @@ -44,6 +44,8 @@ * @eoc1: adc1 end of conversion flag in @csr * @eoc2: adc2 end of conversion flag in @csr * @eoc3: 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; @@ -51,6 +53,8 @@ struct stm32_adc_common_regs { u32 eoc1_msk; u32 eoc2_msk; u32 eoc3_msk; + u32 ier; + u32 eocie_msk; }; struct stm32_adc_priv; @@ -276,6 +280,8 @@ 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 */ @@ -284,8 +290,24 @@ 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) { @@ -296,13 +318,28 @@ 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); -- cgit v1.2.3