diff options
Diffstat (limited to 'drivers/iio/adc/stm32-adc.c')
-rw-r--r-- | drivers/iio/adc/stm32-adc.c | 71 |
1 files changed, 67 insertions, 4 deletions
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index 3b291d72701c..80c3f963527b 100644 --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -117,7 +117,9 @@ struct stm32_adc_regs { * struct stm32_adc_regspec - stm32 registers definition * @dr: data register offset * @ier_eoc: interrupt enable register & eocie bitfield + * @ier_ovr: interrupt enable register & overrun bitfield * @isr_eoc: interrupt status register & eoc bitfield + * @isr_ovr: interrupt status register & overrun bitfield * @sqr: reference to sequence registers array * @exten: trigger control register & bitfield * @extsel: trigger selection register & bitfield @@ -128,7 +130,9 @@ struct stm32_adc_regs { struct stm32_adc_regspec { const u32 dr; const struct stm32_adc_regs ier_eoc; + const struct stm32_adc_regs ier_ovr; const struct stm32_adc_regs isr_eoc; + const struct stm32_adc_regs isr_ovr; const struct stm32_adc_regs *sqr; const struct stm32_adc_regs exten; const struct stm32_adc_regs extsel; @@ -337,7 +341,9 @@ static const unsigned int stm32f4_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = { static const struct stm32_adc_regspec stm32f4_adc_regspec = { .dr = STM32F4_ADC_DR, .ier_eoc = { STM32F4_ADC_CR1, STM32F4_EOCIE }, + .ier_ovr = { STM32F4_ADC_CR1, STM32F4_OVRIE }, .isr_eoc = { STM32F4_ADC_SR, STM32F4_EOC }, + .isr_ovr = { STM32F4_ADC_SR, STM32F4_OVR }, .sqr = stm32f4_sq, .exten = { STM32F4_ADC_CR2, STM32F4_EXTEN_MASK, STM32F4_EXTEN_SHIFT }, .extsel = { STM32F4_ADC_CR2, STM32F4_EXTSEL_MASK, @@ -429,7 +435,9 @@ static const unsigned int stm32h7_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = { static const struct stm32_adc_regspec stm32h7_adc_regspec = { .dr = STM32H7_ADC_DR, .ier_eoc = { STM32H7_ADC_IER, STM32H7_EOCIE }, + .ier_ovr = { STM32H7_ADC_IER, STM32H7_OVRIE }, .isr_eoc = { STM32H7_ADC_ISR, STM32H7_EOC }, + .isr_ovr = { STM32H7_ADC_ISR, STM32H7_OVR }, .sqr = stm32h7_sq, .exten = { STM32H7_ADC_CFGR, STM32H7_EXTEN_MASK, STM32H7_EXTEN_SHIFT }, .extsel = { STM32H7_ADC_CFGR, STM32H7_EXTSEL_MASK, @@ -506,6 +514,18 @@ static void stm32_adc_conv_irq_disable(struct stm32_adc *adc) adc->cfg->regs->ier_eoc.mask); } +static void stm32_adc_ovr_irq_enable(struct stm32_adc *adc) +{ + stm32_adc_set_bits(adc, adc->cfg->regs->ier_ovr.reg, + adc->cfg->regs->ier_ovr.mask); +} + +static void stm32_adc_ovr_irq_disable(struct stm32_adc *adc) +{ + stm32_adc_clr_bits(adc, adc->cfg->regs->ier_ovr.reg, + adc->cfg->regs->ier_ovr.mask); +} + static void stm32_adc_set_res(struct stm32_adc *adc) { const struct stm32_adc_regs *res = &adc->cfg->regs->res; @@ -1205,6 +1225,19 @@ static int stm32_adc_read_raw(struct iio_dev *indio_dev, } } +static irqreturn_t stm32_adc_threaded_isr(int irq, void *data) +{ + struct stm32_adc *adc = data; + struct iio_dev *indio_dev = iio_priv_to_dev(adc); + const struct stm32_adc_regspec *regs = adc->cfg->regs; + u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg); + + if (status & regs->isr_ovr.mask) + dev_err(&indio_dev->dev, "Overrun, stopping: restart needed\n"); + + return IRQ_HANDLED; +} + static irqreturn_t stm32_adc_isr(int irq, void *data) { struct stm32_adc *adc = data; @@ -1212,6 +1245,19 @@ static irqreturn_t stm32_adc_isr(int irq, void *data) const struct stm32_adc_regspec *regs = adc->cfg->regs; u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg); + if (status & regs->isr_ovr.mask) { + /* + * Overrun occurred on regular conversions: data for wrong + * channel may be read. Unconditionally disable interrupts + * to stop processing data and print error message. + * Restarting the capture can be done by disabling, then + * re-enabling it (e.g. write 0, then 1 to buffer/enable). + */ + stm32_adc_ovr_irq_disable(adc); + stm32_adc_conv_irq_disable(adc); + return IRQ_WAKE_THREAD; + } + if (status & regs->isr_eoc.mask) { /* Reading DR also clears EOC status flag */ adc->buffer[adc->bufi] = stm32_adc_readw(adc, regs->dr); @@ -1441,6 +1487,8 @@ static int __stm32_adc_buffer_postenable(struct iio_dev *indio_dev) /* Reset adc buffer index */ adc->bufi = 0; + stm32_adc_ovr_irq_enable(adc); + if (!adc->dma_chan) stm32_adc_conv_irq_enable(adc); @@ -1481,6 +1529,8 @@ static void __stm32_adc_buffer_predisable(struct iio_dev *indio_dev) if (!adc->dma_chan) stm32_adc_conv_irq_disable(adc); + stm32_adc_ovr_irq_disable(adc); + if (adc->dma_chan) dmaengine_terminate_sync(adc->dma_chan); @@ -1746,9 +1796,21 @@ static int stm32_adc_dma_request(struct iio_dev *indio_dev) struct dma_slave_config config; int ret; - adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx"); - if (!adc->dma_chan) + adc->dma_chan = dma_request_chan(&indio_dev->dev, "rx"); + if (IS_ERR(adc->dma_chan)) { + ret = PTR_ERR(adc->dma_chan); + if (ret != -ENODEV) { + if (ret != -EPROBE_DEFER) + dev_err(&indio_dev->dev, + "DMA channel request failed with %d\n", + ret); + return ret; + } + + /* DMA is optional: fall back to IRQ mode */ + adc->dma_chan = NULL; return 0; + } adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, STM32_DMA_BUFFER_SIZE, @@ -1818,8 +1880,9 @@ static int stm32_adc_probe(struct platform_device *pdev) if (adc->irq < 0) return adc->irq; - ret = devm_request_irq(&pdev->dev, adc->irq, stm32_adc_isr, - 0, pdev->name, adc); + ret = devm_request_threaded_irq(&pdev->dev, adc->irq, stm32_adc_isr, + stm32_adc_threaded_isr, + 0, pdev->name, adc); if (ret) { dev_err(&pdev->dev, "failed to request IRQ\n"); return ret; |