diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 383400b678c8..af4fc1279409 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -475,12 +475,13 @@ config MAX9611 called max9611. config MCP320X - tristate "Microchip Technology MCP3x01/02/04/08" + tristate "Microchip Technology MCP3x01/02/04/08 and MCP3550/1/3" depends on SPI help Say yes here to build support for Microchip Technology's MCP3001, MCP3002, MCP3004, MCP3008, MCP3201, MCP3202, MCP3204, - MCP3208 or MCP3301 analog to digital converter. + MCP3208, MCP3301, MCP3550, MCP3551 and MCP3553 analog to digital + converters. This driver can also be built as a module. If so, the module will be called mcp320x. diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c index 32859188d653..a04856d8afdb 100644 --- a/drivers/iio/adc/mcp320x.c +++ b/drivers/iio/adc/mcp320x.c @@ -19,6 +19,11 @@ * ------------ * 13 bit converter * MCP3301 + * ------------ + * 22 bit converter + * MCP3550 + * MCP3551 + * MCP3553 * * Datasheet can be found here: * http://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf mcp3001 @@ -28,6 +33,7 @@ * http://ww1.microchip.com/downloads/en/DeviceDoc/21034D.pdf mcp3202 * http://ww1.microchip.com/downloads/en/DeviceDoc/21298c.pdf mcp3204/08 * http://ww1.microchip.com/downloads/en/DeviceDoc/21700E.pdf mcp3301 + * http://ww1.microchip.com/downloads/en/DeviceDoc/21950D.pdf mcp3550/1/3 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -51,12 +57,17 @@ enum { mcp3204, mcp3208, mcp3301, + mcp3550_50, + mcp3550_60, + mcp3551, + mcp3553, }; struct mcp320x_chip_info { const struct iio_chan_spec *channels; unsigned int num_channels; unsigned int resolution; + unsigned int conv_time; /* usec */ }; /** @@ -64,6 +75,8 @@ struct mcp320x_chip_info { * @spi: SPI slave (parent of the IIO device) * @msg: SPI message to select a channel and receive a value from the ADC * @transfer: SPI transfers used by @msg + * @start_conv_msg: SPI message to start a conversion by briefly asserting CS + * @start_conv_transfer: SPI transfer used by @start_conv_msg * @reg: regulator generating Vref * @lock: protects read sequences * @chip_info: ADC properties @@ -74,13 +87,15 @@ struct mcp320x { struct spi_device *spi; struct spi_message msg; struct spi_transfer transfer[2]; + struct spi_message start_conv_msg; + struct spi_transfer start_conv_transfer; struct regulator *reg; struct mutex lock; const struct mcp320x_chip_info *chip_info; u8 tx_buf ____cacheline_aligned; - u8 rx_buf[2]; + u8 rx_buf[4]; }; static int mcp320x_channel_to_tx_data(int device_index, @@ -109,6 +124,15 @@ static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel, { int ret; + if (adc->chip_info->conv_time) { + ret = spi_sync(adc->spi, &adc->start_conv_msg); + if (ret < 0) + return ret; + + usleep_range(adc->chip_info->conv_time, + adc->chip_info->conv_time + 100); + } + memset(&adc->rx_buf, 0, sizeof(adc->rx_buf)); if (adc->chip_info->num_channels > 1) adc->tx_buf = mcp320x_channel_to_tx_data(device_index, channel, @@ -139,6 +163,31 @@ static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel, *val = sign_extend32((adc->rx_buf[0] & 0x1f) << 8 | adc->rx_buf[1], 12); return 0; + case mcp3550_50: + case mcp3550_60: + case mcp3551: + case mcp3553: { + u32 raw = be32_to_cpup((u32 *)adc->rx_buf); + + if (!(adc->spi->mode & SPI_CPOL)) + raw <<= 1; /* strip Data Ready bit in SPI mode 0,0 */ + + /* + * If the input is within -vref and vref, bit 21 is the sign. + * Up to 12% overrange or underrange are allowed, in which case + * bit 23 is the sign and bit 0 to 21 is the value. + */ + raw >>= 8; + if (raw & BIT(22) && raw & BIT(23)) + return -EIO; /* cannot have overrange AND underrange */ + else if (raw & BIT(22)) + raw &= ~BIT(22); /* overrange */ + else if (raw & BIT(23) || raw & BIT(21)) + raw |= GENMASK(31, 22); /* underrange or negative */ + + *val = (s32)raw; + return 0; + } default: return -EINVAL; } @@ -297,6 +346,31 @@ static const struct mcp320x_chip_info mcp320x_chip_infos[] = { .num_channels = ARRAY_SIZE(mcp3201_channels), .resolution = 13 }, + [mcp3550_50] = { + .channels = mcp3201_channels, + .num_channels = ARRAY_SIZE(mcp3201_channels), + .resolution = 21, + /* 2% max deviation + 144 clock periods to exit shutdown */ + .conv_time = 80000 * 1.02 + 144000 / 102.4, + }, + [mcp3550_60] = { + .channels = mcp3201_channels, + .num_channels = ARRAY_SIZE(mcp3201_channels), + .resolution = 21, + .conv_time = 66670 * 1.02 + 144000 / 122.88, + }, + [mcp3551] = { + .channels = mcp3201_channels, + .num_channels = ARRAY_SIZE(mcp3201_channels), + .resolution = 21, + .conv_time = 73100 * 1.02 + 144000 / 112.64, + }, + [mcp3553] = { + .channels = mcp3201_channels, + .num_channels = ARRAY_SIZE(mcp3201_channels), + .resolution = 21, + .conv_time = 16670 * 1.02 + 144000 / 122.88, + }, }; static int mcp320x_probe(struct spi_device *spi) @@ -304,7 +378,7 @@ static int mcp320x_probe(struct spi_device *spi) struct iio_dev *indio_dev; struct mcp320x *adc; const struct mcp320x_chip_info *chip_info; - int ret; + int ret, device_index; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc)); if (!indio_dev) @@ -320,7 +394,8 @@ static int mcp320x_probe(struct spi_device *spi) indio_dev->info = &mcp320x_info; spi_set_drvdata(spi, indio_dev); - chip_info = &mcp320x_chip_infos[spi_get_device_id(spi)->driver_data]; + device_index = spi_get_device_id(spi)->driver_data; + chip_info = &mcp320x_chip_infos[device_index]; indio_dev->channels = chip_info->channels; indio_dev->num_channels = chip_info->num_channels; @@ -329,7 +404,8 @@ static int mcp320x_probe(struct spi_device *spi) adc->transfer[0].tx_buf = &adc->tx_buf; adc->transfer[0].len = sizeof(adc->tx_buf); adc->transfer[1].rx_buf = adc->rx_buf; - adc->transfer[1].len = sizeof(adc->rx_buf); + adc->transfer[1].len = DIV_ROUND_UP(chip_info->resolution, 8); + if (chip_info->num_channels == 1) /* single-channel converters are rx only (no MOSI pin) */ spi_message_init_with_transfers(&adc->msg, @@ -338,6 +414,32 @@ static int mcp320x_probe(struct spi_device *spi) spi_message_init_with_transfers(&adc->msg, adc->transfer, ARRAY_SIZE(adc->transfer)); + switch (device_index) { + case mcp3550_50: + case mcp3550_60: + case mcp3551: + case mcp3553: + /* rx len increases from 24 to 25 bit in SPI mode 0,0 */ + if (!(spi->mode & SPI_CPOL)) + adc->transfer[1].len++; + + /* conversions are started by asserting CS pin for 8 usec */ + adc->start_conv_transfer.delay_usecs = 8; + spi_message_init_with_transfers(&adc->start_conv_msg, + &adc->start_conv_transfer, 1); + + /* + * If CS was previously kept low (continuous conversion mode) + * and then changed to high, the chip is in shutdown. + * Sometimes it fails to wake from shutdown and clocks out + * only 0xffffff. The magic sequence of performing two + * conversions without delay between them resets the chip + * and ensures all subsequent conversions succeed. + */ + mcp320x_adc_conversion(adc, 0, 1, device_index, &ret); + mcp320x_adc_conversion(adc, 0, 1, device_index, &ret); + } + adc->reg = devm_regulator_get(&spi->dev, "vref"); if (IS_ERR(adc->reg)) return PTR_ERR(adc->reg); @@ -392,6 +494,10 @@ static const struct of_device_id mcp320x_dt_ids[] = { { .compatible = "microchip,mcp3204" }, { .compatible = "microchip,mcp3208" }, { .compatible = "microchip,mcp3301" }, + { .compatible = "microchip,mcp3550-50" }, + { .compatible = "microchip,mcp3550-60" }, + { .compatible = "microchip,mcp3551" }, + { .compatible = "microchip,mcp3553" }, { } }; MODULE_DEVICE_TABLE(of, mcp320x_dt_ids); @@ -407,6 +513,10 @@ static const struct spi_device_id mcp320x_id[] = { { "mcp3204", mcp3204 }, { "mcp3208", mcp3208 }, { "mcp3301", mcp3301 }, + { "mcp3550-50", mcp3550_50 }, + { "mcp3550-60", mcp3550_60 }, + { "mcp3551", mcp3551 }, + { "mcp3553", mcp3553 }, { } }; MODULE_DEVICE_TABLE(spi, mcp320x_id); @@ -423,5 +533,5 @@ static struct spi_driver mcp320x_driver = { module_spi_driver(mcp320x_driver); MODULE_AUTHOR("Oskar Andero "); -MODULE_DESCRIPTION("Microchip Technology MCP3x01/02/04/08"); +MODULE_DESCRIPTION("Microchip Technology MCP3x01/02/04/08 and MCP3550/1/3"); MODULE_LICENSE("GPL v2");