From 08a65f61db69ae4850c3c15e8fbe6293a09a998d Mon Sep 17 00:00:00 2001 From: Marcus Folkesson Date: Mon, 15 Aug 2022 08:16:22 +0200 Subject: [PATCH] iio: adc: mcp3911: add support for interrupts Make it possible to read values upon interrupts. Configure Data Ready Signal Output Pin to either HiZ or push-pull and use it as interrupt source. Signed-off-by: Marcus Folkesson Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20220815061625.35568-7-marcus.folkesson@gmail.com Signed-off-by: Jonathan Cameron --- drivers/iio/adc/mcp3911.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c index 15290a6..4e45ccc 100644 --- a/drivers/iio/adc/mcp3911.c +++ b/drivers/iio/adc/mcp3911.c @@ -31,6 +31,7 @@ #define MCP3911_REG_GAIN 0x09 #define MCP3911_REG_STATUSCOM 0x0a +#define MCP3911_STATUSCOM_DRHIZ BIT(12) #define MCP3911_STATUSCOM_READ GENMASK(7, 6) #define MCP3911_STATUSCOM_CH1_24WIDTH BIT(4) #define MCP3911_STATUSCOM_CH0_24WIDTH BIT(3) @@ -64,6 +65,7 @@ struct mcp3911 { struct regulator *vref; struct clk *clki; u32 dev_addr; + struct iio_trigger *trig; struct { u32 channels[MCP3911_NUM_CHANNELS]; s64 ts __aligned(8); @@ -344,6 +346,23 @@ static void mcp3911_cleanup_regulator(void *vref) regulator_disable(vref); } +static int mcp3911_set_trigger_state(struct iio_trigger *trig, bool enable) +{ + struct mcp3911 *adc = iio_trigger_get_drvdata(trig); + + if (enable) + enable_irq(adc->spi->irq); + else + disable_irq(adc->spi->irq); + + return 0; +} + +static const struct iio_trigger_ops mcp3911_trigger_ops = { + .validate_device = iio_trigger_validate_own_device, + .set_trigger_state = mcp3911_set_trigger_state, +}; + static int mcp3911_probe(struct spi_device *spi) { struct iio_dev *indio_dev; @@ -395,6 +414,15 @@ static int mcp3911_probe(struct spi_device *spi) if (ret) return ret; + if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz")) + ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ, + 0, 2); + else + ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ, + MCP3911_STATUSCOM_DRHIZ, 2); + if (ret) + return ret; + indio_dev->name = spi_get_device_id(spi)->name; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->info = &mcp3911_info; @@ -405,6 +433,31 @@ static int mcp3911_probe(struct spi_device *spi) mutex_init(&adc->lock); + if (spi->irq > 0) { + adc->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d", + indio_dev->name, + iio_device_id(indio_dev)); + if (!adc->trig) + return PTR_ERR(adc->trig); + + adc->trig->ops = &mcp3911_trigger_ops; + iio_trigger_set_drvdata(adc->trig, adc); + ret = devm_iio_trigger_register(&spi->dev, adc->trig); + if (ret) + return ret; + + /* + * The device generates interrupts as long as it is powered up. + * Some platforms might not allow the option to power it down so + * don't enable the interrupt to avoid extra load on the system. + */ + ret = devm_request_irq(&spi->dev, spi->irq, + &iio_trigger_generic_data_rdy_poll, IRQF_NO_AUTOEN | IRQF_ONESHOT, + indio_dev->name, adc->trig); + if (ret) + return ret; + } + ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL, mcp3911_trigger_handler, NULL); -- 2.7.4