diff options
-rw-r--r-- | drivers/iio/adc/Kconfig | 2 | ||||
-rw-r--r-- | drivers/iio/adc/mcp3911.c | 103 |
2 files changed, 97 insertions, 8 deletions
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 56e3ca3b4a5d..791612ca6012 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -732,6 +732,8 @@ config MCP3422 config MCP3911 tristate "Microchip Technology MCP3911 driver" depends on SPI + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER help Say yes here to build support for Microchip Technology's MCP3911 analog to digital converter. diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c index 15b3e5bc85ee..15290a6f9b01 100644 --- a/drivers/iio/adc/mcp3911.c +++ b/drivers/iio/adc/mcp3911.c @@ -5,16 +5,25 @@ * Copyright (C) 2018 Marcus Folkesson <marcus.folkesson@gmail.com> * Copyright (C) 2018 Kent Gustavsson <kent@minoris.se> */ +#include <linux/bitfield.h> +#include <linux/bits.h> #include <linux/clk.h> #include <linux/delay.h> #include <linux/err.h> -#include <linux/iio/iio.h> #include <linux/module.h> #include <linux/mod_devicetable.h> #include <linux/property.h> #include <linux/regulator/consumer.h> #include <linux/spi/spi.h> +#include <linux/iio/iio.h> +#include <linux/iio/buffer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/trigger.h> + +#include <asm/unaligned.h> + #define MCP3911_REG_CHANNEL0 0x00 #define MCP3911_REG_CHANNEL1 0x03 #define MCP3911_REG_MOD 0x06 @@ -22,6 +31,7 @@ #define MCP3911_REG_GAIN 0x09 #define MCP3911_REG_STATUSCOM 0x0a +#define MCP3911_STATUSCOM_READ GENMASK(7, 6) #define MCP3911_STATUSCOM_CH1_24WIDTH BIT(4) #define MCP3911_STATUSCOM_CH0_24WIDTH BIT(3) #define MCP3911_STATUSCOM_EN_OFFCAL BIT(2) @@ -54,6 +64,13 @@ struct mcp3911 { struct regulator *vref; struct clk *clki; u32 dev_addr; + struct { + u32 channels[MCP3911_NUM_CHANNELS]; + s64 ts __aligned(8); + } scan; + + u8 tx_buf __aligned(IIO_DMA_MINALIGN); + u8 rx_buf[MCP3911_NUM_CHANNELS * 3]; }; static int mcp3911_read(struct mcp3911 *adc, u8 reg, u32 *val, u8 len) @@ -196,16 +213,66 @@ out: .type = IIO_VOLTAGE, \ .indexed = 1, \ .channel = idx, \ + .scan_index = idx, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ BIT(IIO_CHAN_INFO_OFFSET) | \ BIT(IIO_CHAN_INFO_SCALE), \ + .scan_type = { \ + .sign = 's', \ + .realbits = 24, \ + .storagebits = 32, \ + .endianness = IIO_BE, \ + }, \ } static const struct iio_chan_spec mcp3911_channels[] = { MCP3911_CHAN(0), MCP3911_CHAN(1), + IIO_CHAN_SOFT_TIMESTAMP(2), }; +static irqreturn_t mcp3911_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct mcp3911 *adc = iio_priv(indio_dev); + struct spi_transfer xfer[] = { + { + .tx_buf = &adc->tx_buf, + .len = 1, + }, { + .rx_buf = adc->rx_buf, + .len = sizeof(adc->rx_buf), + }, + }; + int scan_index; + int i = 0; + int ret; + + mutex_lock(&adc->lock); + adc->tx_buf = MCP3911_REG_READ(MCP3911_CHANNEL(0), adc->dev_addr); + ret = spi_sync_transfer(adc->spi, xfer, ARRAY_SIZE(xfer)); + if (ret < 0) { + dev_warn(&adc->spi->dev, + "failed to get conversion data\n"); + goto out; + } + + for_each_set_bit(scan_index, indio_dev->active_scan_mask, indio_dev->masklength) { + const struct iio_chan_spec *scan_chan = &indio_dev->channels[scan_index]; + + adc->scan.channels[i] = get_unaligned_be24(&adc->rx_buf[scan_chan->channel * 3]); + i++; + } + iio_push_to_buffers_with_timestamp(indio_dev, &adc->scan, + iio_get_time_ns(indio_dev)); +out: + mutex_unlock(&adc->lock); + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + static const struct iio_info mcp3911_info = { .read_raw = mcp3911_read_raw, .write_raw = mcp3911_write_raw, @@ -214,7 +281,7 @@ static const struct iio_info mcp3911_info = { static int mcp3911_config(struct mcp3911 *adc) { struct device *dev = &adc->spi->dev; - u32 configreg; + u32 regval; int ret; ret = device_property_read_u32(dev, "microchip,device-addr", &adc->dev_addr); @@ -233,29 +300,43 @@ static int mcp3911_config(struct mcp3911 *adc) } dev_dbg(&adc->spi->dev, "use device address %i\n", adc->dev_addr); - ret = mcp3911_read(adc, MCP3911_REG_CONFIG, &configreg, 2); + ret = mcp3911_read(adc, MCP3911_REG_CONFIG, ®val, 2); if (ret) return ret; + regval &= ~MCP3911_CONFIG_VREFEXT; if (adc->vref) { dev_dbg(&adc->spi->dev, "use external voltage reference\n"); - configreg |= MCP3911_CONFIG_VREFEXT; + regval |= FIELD_PREP(MCP3911_CONFIG_VREFEXT, 1); } else { dev_dbg(&adc->spi->dev, "use internal voltage reference (1.2V)\n"); - configreg &= ~MCP3911_CONFIG_VREFEXT; + regval |= FIELD_PREP(MCP3911_CONFIG_VREFEXT, 0); } + regval &= ~MCP3911_CONFIG_CLKEXT; if (adc->clki) { dev_dbg(&adc->spi->dev, "use external clock as clocksource\n"); - configreg |= MCP3911_CONFIG_CLKEXT; + regval |= FIELD_PREP(MCP3911_CONFIG_CLKEXT, 1); } else { dev_dbg(&adc->spi->dev, "use crystal oscillator as clocksource\n"); - configreg &= ~MCP3911_CONFIG_CLKEXT; + regval |= FIELD_PREP(MCP3911_CONFIG_CLKEXT, 0); } - return mcp3911_write(adc, MCP3911_REG_CONFIG, configreg, 2); + ret = mcp3911_write(adc, MCP3911_REG_CONFIG, regval, 2); + if (ret) + return ret; + + ret = mcp3911_read(adc, MCP3911_REG_STATUSCOM, ®val, 2); + if (ret) + return ret; + + /* Address counter incremented, cycle through register types */ + regval &= ~MCP3911_STATUSCOM_READ; + regval |= FIELD_PREP(MCP3911_STATUSCOM_READ, 0x02); + + return mcp3911_write(adc, MCP3911_REG_STATUSCOM, regval, 2); } static void mcp3911_cleanup_regulator(void *vref) @@ -324,6 +405,12 @@ static int mcp3911_probe(struct spi_device *spi) mutex_init(&adc->lock); + ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, + NULL, + mcp3911_trigger_handler, NULL); + if (ret) + return ret; + return devm_iio_device_register(&adc->spi->dev, indio_dev); } |