[PATCHv2] iio: adc: Add Maxim MAX11100 driver
Add IIO driver for Maxim MAX11100 single-channel ADC. Add DT bindings documentation. Signed-off-by: Jacopo Mondi --- v1 -> v2: - incorporated pmeerw's review comments - retrieve vref from dts and use that to convert read_raw result to mV - add device tree bindings documentation --- .../devicetree/bindings/iio/adc/max11100.txt | 17 +++ drivers/iio/adc/Kconfig| 9 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/max11100.c | 166 + 4 files changed, 193 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/adc/max11100.txt create mode 100644 drivers/iio/adc/max11100.c diff --git a/Documentation/devicetree/bindings/iio/adc/max11100.txt b/Documentation/devicetree/bindings/iio/adc/max11100.txt new file mode 100644 index 000..6877c11 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/max11100.txt @@ -0,0 +1,17 @@ +* Maxim max11100 Analog to Digital Converter (ADC) + +Required properties: + - compatible: Should be "maxim,max11100" + - vref-supply: phandle to the regulator that provides reference voltage + +Optional properties: + - spi-max-frequency: SPI maximum frequency + +Example: + +adc0: max11100@0 { +compatible = "maxim,max11100"; +vref-supply = <&adc0_vref>; +spi-max-frequency = <24>; +}; + diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 99c0514..a909484 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -285,6 +285,15 @@ config MAX1027 To compile this driver as a module, choose M here: the module will be called max1027. +config MAX11100 + tristate "Maxim max11100 ADC driver" + depends on SPI + help + Say yes here to build support for Maxim max11100 SPI ADC + + To compile this driver as a module, choose M here: the module will be + called max11100. + config MAX1363 tristate "Maxim max1363 ADC driver" depends on I2C diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 7a40c04..1463044 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o obj-$(CONFIG_LTC2485) += ltc2485.o obj-$(CONFIG_MAX1027) += max1027.o +obj-$(CONFIG_MAX11100) += max11100.o obj-$(CONFIG_MAX1363) += max1363.o obj-$(CONFIG_MCP320X) += mcp320x.o obj-$(CONFIG_MCP3422) += mcp3422.o diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c new file mode 100644 index 000..f372ad8 --- /dev/null +++ b/drivers/iio/adc/max11100.c @@ -0,0 +1,166 @@ +/* + * iio/adc/max11100.c + * Maxim max11100 ADC Driver with IIO interface + * + * Copyright (C) 2016 Renesas Electronics Corporation + * Copyright (C) 2016 Jacopo Mondi + * + * 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 + * published by the Free Software Foundation. + */ +#include +#include +#include +#include +#include + +#include +#include +#include + +/* + * LSB is the ADC single digital step + * 1 LSB = (vref / 2 ^ 16) + * AIN = (DIN * LSB) + */ +#define MAX11100_LSB_DIV (1 << 16) +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) + +struct max11100_state { + const struct max11100_chip_desc *desc; + struct spi_device *spi; + int vref_uv; + struct mutex lock; +}; + +static struct iio_chan_spec max11100_channels[] = { + { /* [0] */ + .type = IIO_VOLTAGE, + .scan_type = { + .sign = 'u', + .realbits = 16, + .storagebits = 24, + .shift = 8, + .repeat = 1, + .endianness = IIO_BE, + }, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + }, +}; + +static struct max11100_chip_desc { + unsigned int num_chan; + const struct iio_chan_spec *channels; +} max11100_desc = { + .num_chan = ARRAY_SIZE(max11100_channels), + .channels = max11100_channels, +}; + +static int max11100_read_raw(struct iio_dev *indio_dev, +struct iio_chan_spec const *chan, +int *val, int *val2, long mask) +{ + int ret; + struct max11100_state *state = iio_priv(indio_dev); + uint8_t buffer[3]; + + mutex_lock(&state->lock); + + ret = spi_read(state->spi, buffer, sizeof(buffer)); + if (ret) { + mutex_unlock(&state->lock); + dev_err(&indio_dev->dev, "SPI transfer failed\n"); + return ret; + } + mutex_unlock(&state->lock); + + /* the first 8 bits sent out from ADC must be 0s */ + if (buffer[0]) { + dev_err(&indio_dev->dev, "Invalid value:
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
Hi Jacopo, On Tue, Dec 13, 2016 at 1:37 PM, Jacopo Mondi wrote: > Add IIO driver for Maxim MAX11100 single-channel ADC. > Add DT bindings documentation. > > Signed-off-by: Jacopo Mondi > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o > obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o > obj-$(CONFIG_LTC2485) += ltc2485.o > obj-$(CONFIG_MAX1027) += max1027.o > +obj-$(CONFIG_MAX11100) += max11100.o > obj-$(CONFIG_MAX1363) += max1363.o > obj-$(CONFIG_MCP320X) += mcp320x.o > obj-$(CONFIG_MCP3422) += mcp3422.o > diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c > new file mode 100644 > index 000..f372ad8 > --- /dev/null > +++ b/drivers/iio/adc/max11100.c > +/* > + * LSB is the ADC single digital step > + * 1 LSB = (vref / 2 ^ 16) > + * AIN = (DIN * LSB) > + */ > +#define MAX11100_LSB_DIV (1 << 16) > +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) DIV_ROUND_CLOSEST()? > +struct max11100_state { > + const struct max11100_chip_desc *desc; > + struct spi_device *spi; > + int vref_uv; unsi It's good practice to move the smaller members to the end of the structure, to avoid gaps due to alignment rules (struct mutex needs to be 64-bit aligned on 64-bit platforms). > + struct mutex lock; > +}; > +static struct max11100_chip_desc { > + unsigned int num_chan; > + const struct iio_chan_spec *channels; Same here (but it won't have any effect for now). > +} max11100_desc = { > + .num_chan = ARRAY_SIZE(max11100_channels), > + .channels = max11100_channels, > +}; > +static int max11100_read_raw(struct iio_dev *indio_dev, > +struct iio_chan_spec const *chan, > +int *val, int *val2, long mask) > +{ > + int ret; > + struct max11100_state *state = iio_priv(indio_dev); > + uint8_t buffer[3]; > + *val = be16_to_cpu(*(uint16_t *)&buffer[1]); Reading the uint16_t will be an unaligned load, which is not supported on all platforms. So you either have to use get_unaligned_le16(), or assemble the value yourself, like you did in v1. > + *val = *val * MAX11100_LSB(state->vref_uv) / 1000; DIV_ROUND_CLOSEST()? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
> > +struct max11100_state { > > + const struct max11100_chip_desc *desc; > > + struct spi_device *spi; > > + int vref_uv; > > unsi > It's good practice to move the smaller members to the end of the structure, > to avoid gaps due to alignment rules (struct mutex needs to be 64-bit aligned > on 64-bit platforms). One option. Another idea is to put the most used members to the front to increase chances of being in the same cacheline. signature.asc Description: PGP signature
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
> Add IIO driver for Maxim MAX11100 single-channel ADC. > Add DT bindings documentation. some more comments > Signed-off-by: Jacopo Mondi > --- > > v1 -> v2: > - incorporated pmeerw's review comments > - retrieve vref from dts and use that to convert read_raw result > to mV > - add device tree bindings documentation > > --- > .../devicetree/bindings/iio/adc/max11100.txt | 17 +++ > drivers/iio/adc/Kconfig| 9 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/max11100.c | 166 > + > 4 files changed, 193 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/adc/max11100.txt > create mode 100644 drivers/iio/adc/max11100.c > > diff --git a/Documentation/devicetree/bindings/iio/adc/max11100.txt > b/Documentation/devicetree/bindings/iio/adc/max11100.txt > new file mode 100644 > index 000..6877c11 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/adc/max11100.txt > @@ -0,0 +1,17 @@ > +* Maxim max11100 Analog to Digital Converter (ADC) > + > +Required properties: > + - compatible: Should be "maxim,max11100" > + - vref-supply: phandle to the regulator that provides reference voltage > + > +Optional properties: > + - spi-max-frequency: SPI maximum frequency > + > +Example: > + > +adc0: max11100@0 { > +compatible = "maxim,max11100"; > +vref-supply = <&adc0_vref>; > +spi-max-frequency = <24>; > +}; > + > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 99c0514..a909484 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -285,6 +285,15 @@ config MAX1027 > To compile this driver as a module, choose M here: the module will be > called max1027. > > +config MAX11100 > + tristate "Maxim max11100 ADC driver" > + depends on SPI SPI_MASTER is more precise I think > + help > + Say yes here to build support for Maxim max11100 SPI ADC > + > + To compile this driver as a module, choose M here: the module will be > + called max11100. > + > config MAX1363 > tristate "Maxim max1363 ADC driver" > depends on I2C > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index 7a40c04..1463044 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o > obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o > obj-$(CONFIG_LTC2485) += ltc2485.o > obj-$(CONFIG_MAX1027) += max1027.o > +obj-$(CONFIG_MAX11100) += max11100.o > obj-$(CONFIG_MAX1363) += max1363.o > obj-$(CONFIG_MCP320X) += mcp320x.o > obj-$(CONFIG_MCP3422) += mcp3422.o > diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c > new file mode 100644 > index 000..f372ad8 > --- /dev/null > +++ b/drivers/iio/adc/max11100.c > @@ -0,0 +1,166 @@ > +/* > + * iio/adc/max11100.c > + * Maxim max11100 ADC Driver with IIO interface > + * > + * Copyright (C) 2016 Renesas Electronics Corporation > + * Copyright (C) 2016 Jacopo Mondi > + * > + * 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 > + * published by the Free Software Foundation. > + */ > +#include > +#include > +#include > +#include > +#include > + > +#include > +#include > +#include > + > +/* > + * LSB is the ADC single digital step > + * 1 LSB = (vref / 2 ^ 16) > + * AIN = (DIN * LSB) > + */ > +#define MAX11100_LSB_DIV (1 << 16) > +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) maybe parenthesis around vref > + > +struct max11100_state { > + const struct max11100_chip_desc *desc; > + struct spi_device *spi; > + int vref_uv; > + struct mutex lock; > +}; > + > +static struct iio_chan_spec max11100_channels[] = { > + { /* [0] */ > + .type = IIO_VOLTAGE, > + .scan_type = { scan_type not needed since driver does not support buffered reads > + .sign = 'u', > + .realbits = 16, > + .storagebits = 24, > + .shift = 8, > + .repeat = 1, > + .endianness = IIO_BE, > + }, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > + }, > +}; > + > +static struct max11100_chip_desc { > + unsigned int num_chan; > + const struct iio_chan_spec *channels; > +} max11100_desc = { > + .num_chan = ARRAY_SIZE(max11100_channels), > + .channels = max11100_channels, > +}; > + > +static int max11100_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + int ret; > + struct max11100_state *state = iio_priv(indio_dev); > + uint8_t buffer[3]; > + > + mutex_lock(&state->lock); > + > + ret = spi_r
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
Hello Peter, thanks for review On 13/12/2016 21:33, Peter Meerwald-Stadler wrote: Add IIO driver for Maxim MAX11100 single-channel ADC. Add DT bindings documentation. some more comments Signed-off-by: Jacopo Mondi --- v1 -> v2: - incorporated pmeerw's review comments - retrieve vref from dts and use that to convert read_raw result to mV - add device tree bindings documentation --- .../devicetree/bindings/iio/adc/max11100.txt | 17 +++ drivers/iio/adc/Kconfig| 9 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/max11100.c | 166 + 4 files changed, 193 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/adc/max11100.txt create mode 100644 drivers/iio/adc/max11100.c diff --git a/Documentation/devicetree/bindings/iio/adc/max11100.txt b/Documentation/devicetree/bindings/iio/adc/max11100.txt new file mode 100644 index 000..6877c11 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/max11100.txt @@ -0,0 +1,17 @@ +* Maxim max11100 Analog to Digital Converter (ADC) + +Required properties: + - compatible: Should be "maxim,max11100" + - vref-supply: phandle to the regulator that provides reference voltage + +Optional properties: + - spi-max-frequency: SPI maximum frequency + +Example: + +adc0: max11100@0 { +compatible = "maxim,max11100"; +vref-supply = <&adc0_vref>; +spi-max-frequency = <24>; +}; + diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 99c0514..a909484 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -285,6 +285,15 @@ config MAX1027 To compile this driver as a module, choose M here: the module will be called max1027. +config MAX11100 + tristate "Maxim max11100 ADC driver" + depends on SPI SPI_MASTER is more precise I think + help + Say yes here to build support for Maxim max11100 SPI ADC + + To compile this driver as a module, choose M here: the module will be + called max11100. + config MAX1363 tristate "Maxim max1363 ADC driver" depends on I2C diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 7a40c04..1463044 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o obj-$(CONFIG_LTC2485) += ltc2485.o obj-$(CONFIG_MAX1027) += max1027.o +obj-$(CONFIG_MAX11100) += max11100.o obj-$(CONFIG_MAX1363) += max1363.o obj-$(CONFIG_MCP320X) += mcp320x.o obj-$(CONFIG_MCP3422) += mcp3422.o diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c new file mode 100644 index 000..f372ad8 --- /dev/null +++ b/drivers/iio/adc/max11100.c @@ -0,0 +1,166 @@ +/* + * iio/adc/max11100.c + * Maxim max11100 ADC Driver with IIO interface + * + * Copyright (C) 2016 Renesas Electronics Corporation + * Copyright (C) 2016 Jacopo Mondi + * + * 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 + * published by the Free Software Foundation. + */ +#include +#include +#include +#include +#include + +#include +#include +#include + +/* + * LSB is the ADC single digital step + * 1 LSB = (vref / 2 ^ 16) + * AIN = (DIN * LSB) + */ +#define MAX11100_LSB_DIV (1 << 16) +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) maybe parenthesis around vref + +struct max11100_state { + const struct max11100_chip_desc *desc; + struct spi_device *spi; + int vref_uv; + struct mutex lock; +}; + +static struct iio_chan_spec max11100_channels[] = { + { /* [0] */ + .type = IIO_VOLTAGE, + .scan_type = { scan_type not needed since driver does not support buffered reads + .sign = 'u', + .realbits = 16, + .storagebits = 24, + .shift = 8, + .repeat = 1, + .endianness = IIO_BE, + }, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + }, +}; + +static struct max11100_chip_desc { + unsigned int num_chan; + const struct iio_chan_spec *channels; +} max11100_desc = { + .num_chan = ARRAY_SIZE(max11100_channels), + .channels = max11100_channels, +}; + +static int max11100_read_raw(struct iio_dev *indio_dev, +struct iio_chan_spec const *chan, +int *val, int *val2, long mask) +{ + int ret; + struct max11100_state *state = iio_priv(indio_dev); + uint8_t buffer[3]; + + mutex_lock(&state->lock); + + ret = spi_read(state->spi, buffer, sizeof(buffer)); + if (ret) { + mutex_unlock(&state->lock); + dev_err(&indio
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
Hi Geert, On 13/12/2016 14:21, Geert Uytterhoeven wrote: Hi Jacopo, On Tue, Dec 13, 2016 at 1:37 PM, Jacopo Mondi wrote: Add IIO driver for Maxim MAX11100 single-channel ADC. Add DT bindings documentation. Signed-off-by: Jacopo Mondi --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o obj-$(CONFIG_LTC2485) += ltc2485.o obj-$(CONFIG_MAX1027) += max1027.o +obj-$(CONFIG_MAX11100) += max11100.o obj-$(CONFIG_MAX1363) += max1363.o obj-$(CONFIG_MCP320X) += mcp320x.o obj-$(CONFIG_MCP3422) += mcp3422.o diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c new file mode 100644 index 000..f372ad8 --- /dev/null +++ b/drivers/iio/adc/max11100.c +/* + * LSB is the ADC single digital step + * 1 LSB = (vref / 2 ^ 16) + * AIN = (DIN * LSB) + */ +#define MAX11100_LSB_DIV (1 << 16) +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) DIV_ROUND_CLOSEST()? +struct max11100_state { + const struct max11100_chip_desc *desc; + struct spi_device *spi; + int vref_uv; unsi Was this a suggestion to turn "vref_uv" into unsigned? As you can see in probe function it can get assigned to -EINVAL when a dummy regulator is returned from regulator-core. I had to make it signed for this reason Thanks j It's good practice to move the smaller members to the end of the structure, to avoid gaps due to alignment rules (struct mutex needs to be 64-bit aligned on 64-bit platforms). + struct mutex lock; +}; +static struct max11100_chip_desc { + unsigned int num_chan; + const struct iio_chan_spec *channels; Same here (but it won't have any effect for now). +} max11100_desc = { + .num_chan = ARRAY_SIZE(max11100_channels), + .channels = max11100_channels, +}; +static int max11100_read_raw(struct iio_dev *indio_dev, +struct iio_chan_spec const *chan, +int *val, int *val2, long mask) +{ + int ret; + struct max11100_state *state = iio_priv(indio_dev); + uint8_t buffer[3]; + *val = be16_to_cpu(*(uint16_t *)&buffer[1]); Reading the uint16_t will be an unaligned load, which is not supported on all platforms. So you either have to use get_unaligned_le16(), or assemble the value yourself, like you did in v1. + *val = *val * MAX11100_LSB(state->vref_uv) / 1000; DIV_ROUND_CLOSEST()? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
Hi Jacopo, On Wed, Dec 14, 2016 at 12:54 PM, jac...@jmondi.org wrote: >>> +struct max11100_state { >>> + const struct max11100_chip_desc *desc; >>> + struct spi_device *spi; >>> + int vref_uv; >> >> unsi > > Was this a suggestion to turn "vref_uv" into unsigned? It was a suggestion I started writing, and aborted improperly when noticing the below ;-) > As you can see in probe function it can get assigned to -EINVAL when a dummy > regulator is returned from regulator-core. > I had to make it signed for this reason Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
On 13/12/16 12:37, Jacopo Mondi wrote: > Add IIO driver for Maxim MAX11100 single-channel ADC. > Add DT bindings documentation. > > Signed-off-by: Jacopo Mondi A quick process related thing. Please don't post a new version of a driver as a reply to an old version. It very rapidly leads to deep and difficult to follow threads. Much easier to just start a new thread. > --- > > v1 -> v2: > - incorporated pmeerw's review comments > - retrieve vref from dts and use that to convert read_raw result > to mV > - add device tree bindings documentation > > --- > .../devicetree/bindings/iio/adc/max11100.txt | 17 +++ > drivers/iio/adc/Kconfig| 9 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/max11100.c | 166 > + > 4 files changed, 193 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/adc/max11100.txt > create mode 100644 drivers/iio/adc/max11100.c > > diff --git a/Documentation/devicetree/bindings/iio/adc/max11100.txt > b/Documentation/devicetree/bindings/iio/adc/max11100.txt > new file mode 100644 > index 000..6877c11 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/adc/max11100.txt > @@ -0,0 +1,17 @@ > +* Maxim max11100 Analog to Digital Converter (ADC) > + > +Required properties: > + - compatible: Should be "maxim,max11100" > + - vref-supply: phandle to the regulator that provides reference voltage > + > +Optional properties: > + - spi-max-frequency: SPI maximum frequency > + > +Example: > + > +adc0: max11100@0 { > +compatible = "maxim,max11100"; > +vref-supply = <&adc0_vref>; > +spi-max-frequency = <24>; > +}; > + > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 99c0514..a909484 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -285,6 +285,15 @@ config MAX1027 > To compile this driver as a module, choose M here: the module will be > called max1027. > > +config MAX11100 > + tristate "Maxim max11100 ADC driver" > + depends on SPI > + help > + Say yes here to build support for Maxim max11100 SPI ADC > + > + To compile this driver as a module, choose M here: the module will be > + called max11100. > + > config MAX1363 > tristate "Maxim max1363 ADC driver" > depends on I2C > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index 7a40c04..1463044 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o > obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o > obj-$(CONFIG_LTC2485) += ltc2485.o > obj-$(CONFIG_MAX1027) += max1027.o > +obj-$(CONFIG_MAX11100) += max11100.o > obj-$(CONFIG_MAX1363) += max1363.o > obj-$(CONFIG_MCP320X) += mcp320x.o > obj-$(CONFIG_MCP3422) += mcp3422.o > diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c > new file mode 100644 > index 000..f372ad8 > --- /dev/null > +++ b/drivers/iio/adc/max11100.c > @@ -0,0 +1,166 @@ > +/* > + * iio/adc/max11100.c > + * Maxim max11100 ADC Driver with IIO interface > + * > + * Copyright (C) 2016 Renesas Electronics Corporation > + * Copyright (C) 2016 Jacopo Mondi > + * > + * 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 > + * published by the Free Software Foundation. > + */ > +#include > +#include > +#include > +#include > +#include > + > +#include > +#include > +#include > + > +/* > + * LSB is the ADC single digital step > + * 1 LSB = (vref / 2 ^ 16) > + * AIN = (DIN * LSB) > + */ > +#define MAX11100_LSB_DIV (1 << 16) > +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) > + > +struct max11100_state { > + const struct max11100_chip_desc *desc; > + struct spi_device *spi; > + int vref_uv; > + struct mutex lock; > +}; > + > +static struct iio_chan_spec max11100_channels[] = { > + { /* [0] */ > + .type = IIO_VOLTAGE, > + .scan_type = { > + .sign = 'u', > + .realbits = 16, > + .storagebits = 24, > + .shift = 8, > + .repeat = 1, > + .endianness = IIO_BE, > + }, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > + }, > +}; > + > +static struct max11100_chip_desc { > + unsigned int num_chan; > + const struct iio_chan_spec *channels; > +} max11100_desc = { > + .num_chan = ARRAY_SIZE(max11100_channels), > + .channels = max11100_channels, > +}; > + > +static int max11100_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + int ret; > + struct max11100_state *state = iio_priv(indio_d
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
On 13/12/16 15:53, Wolfram Sang wrote: > >>> +struct max11100_state { >>> + const struct max11100_chip_desc *desc; >>> + struct spi_device *spi; >>> + int vref_uv; >> >> unsi >> It's good practice to move the smaller members to the end of the structure, >> to avoid gaps due to alignment rules (struct mutex needs to be 64-bit aligned >> on 64-bit platforms). > > One option. Another idea is to put the most used members to the front to > increase chances of being in the same cacheline. > Or more cynically, just put them in the order that makes most logical sense as that gives you fewest grumpy reviewers. We aren't really talking high performance stuff here! Jonathan
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
On 14/12/16 12:00, jac...@jmondi.org wrote: > Hello Peter, >thanks for review > > On 13/12/2016 21:33, Peter Meerwald-Stadler wrote: >> >>> Add IIO driver for Maxim MAX11100 single-channel ADC. >>> Add DT bindings documentation. >> >> some more comments >> >>> Signed-off-by: Jacopo Mondi >>> --- >>> >>> v1 -> v2: >>> - incorporated pmeerw's review comments >>> - retrieve vref from dts and use that to convert read_raw result >>> to mV >>> - add device tree bindings documentation >>> >>> --- >>> .../devicetree/bindings/iio/adc/max11100.txt | 17 +++ >>> drivers/iio/adc/Kconfig| 9 ++ >>> drivers/iio/adc/Makefile | 1 + >>> drivers/iio/adc/max11100.c | 166 >>> + >>> 4 files changed, 193 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/iio/adc/max11100.txt >>> create mode 100644 drivers/iio/adc/max11100.c >>> >>> diff --git a/Documentation/devicetree/bindings/iio/adc/max11100.txt >>> b/Documentation/devicetree/bindings/iio/adc/max11100.txt >>> new file mode 100644 >>> index 000..6877c11 >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/iio/adc/max11100.txt >>> @@ -0,0 +1,17 @@ >>> +* Maxim max11100 Analog to Digital Converter (ADC) >>> + >>> +Required properties: >>> + - compatible: Should be "maxim,max11100" >>> + - vref-supply: phandle to the regulator that provides reference voltage >>> + >>> +Optional properties: >>> + - spi-max-frequency: SPI maximum frequency >>> + >>> +Example: >>> + >>> +adc0: max11100@0 { >>> +compatible = "maxim,max11100"; >>> +vref-supply = <&adc0_vref>; >>> +spi-max-frequency = <24>; >>> +}; >>> + >>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig >>> index 99c0514..a909484 100644 >>> --- a/drivers/iio/adc/Kconfig >>> +++ b/drivers/iio/adc/Kconfig >>> @@ -285,6 +285,15 @@ config MAX1027 >>>To compile this driver as a module, choose M here: the module will be >>>called max1027. >>> >>> +config MAX11100 >>> +tristate "Maxim max11100 ADC driver" >>> +depends on SPI >> >> SPI_MASTER is more precise I think >> >>> +help >>> + Say yes here to build support for Maxim max11100 SPI ADC >>> + >>> + To compile this driver as a module, choose M here: the module will be >>> + called max11100. >>> + >>> config MAX1363 >>> tristate "Maxim max1363 ADC driver" >>> depends on I2C >>> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile >>> index 7a40c04..1463044 100644 >>> --- a/drivers/iio/adc/Makefile >>> +++ b/drivers/iio/adc/Makefile >>> @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o >>> obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o >>> obj-$(CONFIG_LTC2485) += ltc2485.o >>> obj-$(CONFIG_MAX1027) += max1027.o >>> +obj-$(CONFIG_MAX11100) += max11100.o >>> obj-$(CONFIG_MAX1363) += max1363.o >>> obj-$(CONFIG_MCP320X) += mcp320x.o >>> obj-$(CONFIG_MCP3422) += mcp3422.o >>> diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c >>> new file mode 100644 >>> index 000..f372ad8 >>> --- /dev/null >>> +++ b/drivers/iio/adc/max11100.c >>> @@ -0,0 +1,166 @@ >>> +/* >>> + * iio/adc/max11100.c >>> + * Maxim max11100 ADC Driver with IIO interface >>> + * >>> + * Copyright (C) 2016 Renesas Electronics Corporation >>> + * Copyright (C) 2016 Jacopo Mondi >>> + * >>> + * 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 >>> + * published by the Free Software Foundation. >>> + */ >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> + >>> +#include >>> +#include >>> +#include >>> + >>> +/* >>> + * LSB is the ADC single digital step >>> + * 1 LSB = (vref / 2 ^ 16) >>> + * AIN = (DIN * LSB) >>> + */ >>> +#define MAX11100_LSB_DIV(1 << 16) >>> +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) >> >> maybe parenthesis around vref >> >>> + >>> +struct max11100_state { >>> +const struct max11100_chip_desc *desc; >>> +struct spi_device *spi; >>> +int vref_uv; >>> +struct mutex lock; >>> +}; >>> + >>> +static struct iio_chan_spec max11100_channels[] = { >>> +{ /* [0] */ >>> +.type = IIO_VOLTAGE, >>> +.scan_type = { >> >> scan_type not needed since driver does not support buffered reads >> >>> +.sign = 'u', >>> +.realbits = 16, >>> +.storagebits = 24, >>> +.shift = 8, >>> +.repeat = 1, >>> +.endianness = IIO_BE, >>> +}, >>> +.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), >>> +}, >>> +}; >>> + >>> +static struct max11100_chip_desc { >>> +unsigned int num_chan; >>> +const struct iio_chan_spec *channels; >>> +} max11100_desc = { >>> +.num_chan = ARRAY_SIZE(max11100_channels), >>> +.channels = max11100_channels, >>> +}; >>> + >>> +sta
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
On 13/12/16 12:37, Jacopo Mondi wrote: > Add IIO driver for Maxim MAX11100 single-channel ADC. > Add DT bindings documentation. > > Signed-off-by: Jacopo Mondi Nothing significant to add, but a few comments inline. Jonathan > --- > > v1 -> v2: > - incorporated pmeerw's review comments > - retrieve vref from dts and use that to convert read_raw result > to mV > - add device tree bindings documentation > > --- > .../devicetree/bindings/iio/adc/max11100.txt | 17 +++ > drivers/iio/adc/Kconfig| 9 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/max11100.c | 166 > + > 4 files changed, 193 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/adc/max11100.txt > create mode 100644 drivers/iio/adc/max11100.c > > diff --git a/Documentation/devicetree/bindings/iio/adc/max11100.txt > b/Documentation/devicetree/bindings/iio/adc/max11100.txt > new file mode 100644 > index 000..6877c11 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/adc/max11100.txt > @@ -0,0 +1,17 @@ > +* Maxim max11100 Analog to Digital Converter (ADC) > + > +Required properties: > + - compatible: Should be "maxim,max11100" > + - vref-supply: phandle to the regulator that provides reference voltage > + > +Optional properties: > + - spi-max-frequency: SPI maximum frequency > + > +Example: > + > +adc0: max11100@0 { > +compatible = "maxim,max11100"; > +vref-supply = <&adc0_vref>; > +spi-max-frequency = <24>; > +}; > + > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 99c0514..a909484 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -285,6 +285,15 @@ config MAX1027 > To compile this driver as a module, choose M here: the module will be > called max1027. > > +config MAX11100 > + tristate "Maxim max11100 ADC driver" > + depends on SPI > + help > + Say yes here to build support for Maxim max11100 SPI ADC > + > + To compile this driver as a module, choose M here: the module will be > + called max11100. > + > config MAX1363 > tristate "Maxim max1363 ADC driver" > depends on I2C > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index 7a40c04..1463044 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o > obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o > obj-$(CONFIG_LTC2485) += ltc2485.o > obj-$(CONFIG_MAX1027) += max1027.o > +obj-$(CONFIG_MAX11100) += max11100.o > obj-$(CONFIG_MAX1363) += max1363.o > obj-$(CONFIG_MCP320X) += mcp320x.o > obj-$(CONFIG_MCP3422) += mcp3422.o > diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c > new file mode 100644 > index 000..f372ad8 > --- /dev/null > +++ b/drivers/iio/adc/max11100.c > @@ -0,0 +1,166 @@ > +/* > + * iio/adc/max11100.c > + * Maxim max11100 ADC Driver with IIO interface > + * > + * Copyright (C) 2016 Renesas Electronics Corporation > + * Copyright (C) 2016 Jacopo Mondi > + * > + * 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 > + * published by the Free Software Foundation. > + */ > +#include > +#include > +#include > +#include > +#include > + > +#include > +#include > +#include > + > +/* > + * LSB is the ADC single digital step > + * 1 LSB = (vref / 2 ^ 16) > + * AIN = (DIN * LSB) > + */ > +#define MAX11100_LSB_DIV (1 << 16) > +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) > + > +struct max11100_state { > + const struct max11100_chip_desc *desc; > + struct spi_device *spi; > + int vref_uv; > + struct mutex lock; > +}; > + > +static struct iio_chan_spec max11100_channels[] = { > + { /* [0] */ > + .type = IIO_VOLTAGE, > + .scan_type = { > + .sign = 'u', > + .realbits = 16, > + .storagebits = 24, > + .shift = 8, > + .repeat = 1, > + .endianness = IIO_BE, > + }, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > + }, > +}; > + > +static struct max11100_chip_desc { > + unsigned int num_chan; > + const struct iio_chan_spec *channels; > +} max11100_desc = { > + .num_chan = ARRAY_SIZE(max11100_channels), > + .channels = max11100_channels, > +}; > + > +static int max11100_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + int ret; > + struct max11100_state *state = iio_priv(indio_dev); > + uint8_t buffer[3]; > + > + mutex_lock(&state->lock); > + > + ret = spi_read(state->spi, buffer, sizeof(buffer)); > + if (
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
Hi Jonathan, On 30/12/2016 17:08, Jonathan Cameron wrote: On 13/12/16 12:37, Jacopo Mondi wrote: Add IIO driver for Maxim MAX11100 single-channel ADC. Add DT bindings documentation. Signed-off-by: Jacopo Mondi A quick process related thing. Please don't post a new version of a driver as a reply to an old version. It very rapidly leads to deep and difficult to follow threads. Much easier to just start a new thread. Noted! Thanks for suggestion ;) j --- v1 -> v2: - incorporated pmeerw's review comments - retrieve vref from dts and use that to convert read_raw result to mV - add device tree bindings documentation --- .../devicetree/bindings/iio/adc/max11100.txt | 17 +++ drivers/iio/adc/Kconfig| 9 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/max11100.c | 166 + 4 files changed, 193 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/adc/max11100.txt create mode 100644 drivers/iio/adc/max11100.c diff --git a/Documentation/devicetree/bindings/iio/adc/max11100.txt b/Documentation/devicetree/bindings/iio/adc/max11100.txt new file mode 100644 index 000..6877c11 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/max11100.txt @@ -0,0 +1,17 @@ +* Maxim max11100 Analog to Digital Converter (ADC) + +Required properties: + - compatible: Should be "maxim,max11100" + - vref-supply: phandle to the regulator that provides reference voltage + +Optional properties: + - spi-max-frequency: SPI maximum frequency + +Example: + +adc0: max11100@0 { +compatible = "maxim,max11100"; +vref-supply = <&adc0_vref>; +spi-max-frequency = <24>; +}; + diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 99c0514..a909484 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -285,6 +285,15 @@ config MAX1027 To compile this driver as a module, choose M here: the module will be called max1027. +config MAX11100 + tristate "Maxim max11100 ADC driver" + depends on SPI + help + Say yes here to build support for Maxim max11100 SPI ADC + + To compile this driver as a module, choose M here: the module will be + called max11100. + config MAX1363 tristate "Maxim max1363 ADC driver" depends on I2C diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 7a40c04..1463044 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o obj-$(CONFIG_LTC2485) += ltc2485.o obj-$(CONFIG_MAX1027) += max1027.o +obj-$(CONFIG_MAX11100) += max11100.o obj-$(CONFIG_MAX1363) += max1363.o obj-$(CONFIG_MCP320X) += mcp320x.o obj-$(CONFIG_MCP3422) += mcp3422.o diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c new file mode 100644 index 000..f372ad8 --- /dev/null +++ b/drivers/iio/adc/max11100.c @@ -0,0 +1,166 @@ +/* + * iio/adc/max11100.c + * Maxim max11100 ADC Driver with IIO interface + * + * Copyright (C) 2016 Renesas Electronics Corporation + * Copyright (C) 2016 Jacopo Mondi + * + * 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 + * published by the Free Software Foundation. + */ +#include +#include +#include +#include +#include + +#include +#include +#include + +/* + * LSB is the ADC single digital step + * 1 LSB = (vref / 2 ^ 16) + * AIN = (DIN * LSB) + */ +#define MAX11100_LSB_DIV (1 << 16) +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) + +struct max11100_state { + const struct max11100_chip_desc *desc; + struct spi_device *spi; + int vref_uv; + struct mutex lock; +}; + +static struct iio_chan_spec max11100_channels[] = { + { /* [0] */ + .type = IIO_VOLTAGE, + .scan_type = { + .sign = 'u', + .realbits = 16, + .storagebits = 24, + .shift = 8, + .repeat = 1, + .endianness = IIO_BE, + }, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + }, +}; + +static struct max11100_chip_desc { + unsigned int num_chan; + const struct iio_chan_spec *channels; +} max11100_desc = { + .num_chan = ARRAY_SIZE(max11100_channels), + .channels = max11100_channels, +}; + +static int max11100_read_raw(struct iio_dev *indio_dev, +struct iio_chan_spec const *chan, +int *val, int *val2, long mask) +{ + int ret; + struct max11100_state *state = iio_priv(indio_dev); + uint8_t buffer[3]; + + mutex_lock(&state->lock); + + ret = spi_read(state->spi, buffer, sizeof(buf
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
Hi Jonathan, thanks for review On 30/12/2016 17:31, Jonathan Cameron wrote: On 14/12/16 12:00, jac...@jmondi.org wrote: Hello Peter, thanks for review On 13/12/2016 21:33, Peter Meerwald-Stadler wrote: Add IIO driver for Maxim MAX11100 single-channel ADC. Add DT bindings documentation. some more comments Signed-off-by: Jacopo Mondi --- v1 -> v2: - incorporated pmeerw's review comments - retrieve vref from dts and use that to convert read_raw result to mV - add device tree bindings documentation --- .../devicetree/bindings/iio/adc/max11100.txt | 17 +++ drivers/iio/adc/Kconfig| 9 ++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/max11100.c | 166 + 4 files changed, 193 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/adc/max11100.txt create mode 100644 drivers/iio/adc/max11100.c diff --git a/Documentation/devicetree/bindings/iio/adc/max11100.txt b/Documentation/devicetree/bindings/iio/adc/max11100.txt new file mode 100644 index 000..6877c11 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/max11100.txt @@ -0,0 +1,17 @@ +* Maxim max11100 Analog to Digital Converter (ADC) + +Required properties: + - compatible: Should be "maxim,max11100" + - vref-supply: phandle to the regulator that provides reference voltage + +Optional properties: + - spi-max-frequency: SPI maximum frequency + +Example: + +adc0: max11100@0 { +compatible = "maxim,max11100"; +vref-supply = <&adc0_vref>; +spi-max-frequency = <24>; +}; + diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 99c0514..a909484 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -285,6 +285,15 @@ config MAX1027 To compile this driver as a module, choose M here: the module will be called max1027. +config MAX11100 +tristate "Maxim max11100 ADC driver" +depends on SPI SPI_MASTER is more precise I think +help + Say yes here to build support for Maxim max11100 SPI ADC + + To compile this driver as a module, choose M here: the module will be + called max11100. + config MAX1363 tristate "Maxim max1363 ADC driver" depends on I2C diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 7a40c04..1463044 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o obj-$(CONFIG_LTC2485) += ltc2485.o obj-$(CONFIG_MAX1027) += max1027.o +obj-$(CONFIG_MAX11100) += max11100.o obj-$(CONFIG_MAX1363) += max1363.o obj-$(CONFIG_MCP320X) += mcp320x.o obj-$(CONFIG_MCP3422) += mcp3422.o diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c new file mode 100644 index 000..f372ad8 --- /dev/null +++ b/drivers/iio/adc/max11100.c @@ -0,0 +1,166 @@ +/* + * iio/adc/max11100.c + * Maxim max11100 ADC Driver with IIO interface + * + * Copyright (C) 2016 Renesas Electronics Corporation + * Copyright (C) 2016 Jacopo Mondi + * + * 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 + * published by the Free Software Foundation. + */ +#include +#include +#include +#include +#include + +#include +#include +#include + +/* + * LSB is the ADC single digital step + * 1 LSB = (vref / 2 ^ 16) + * AIN = (DIN * LSB) + */ +#define MAX11100_LSB_DIV(1 << 16) +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) maybe parenthesis around vref + +struct max11100_state { +const struct max11100_chip_desc *desc; +struct spi_device *spi; +int vref_uv; +struct mutex lock; +}; + +static struct iio_chan_spec max11100_channels[] = { +{ /* [0] */ +.type = IIO_VOLTAGE, +.scan_type = { scan_type not needed since driver does not support buffered reads +.sign = 'u', +.realbits = 16, +.storagebits = 24, +.shift = 8, +.repeat = 1, +.endianness = IIO_BE, +}, +.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), +}, +}; + +static struct max11100_chip_desc { +unsigned int num_chan; +const struct iio_chan_spec *channels; +} max11100_desc = { +.num_chan = ARRAY_SIZE(max11100_channels), +.channels = max11100_channels, +}; + +static int max11100_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ +int ret; +struct max11100_state *state = iio_priv(indio_dev); +uint8_t buffer[3]; + +mutex_lock(&state->lock); + +ret = spi_read(state->spi, buffer, sizeof(buffer)); +if (ret) { +mutex_unlock(&state->lock); +dev_err(&indio_dev->dev, "SPI transfer failed\n"); +return ret; +} +mutex_unlock(&state->lo
Re: [PATCHv2] iio: adc: Add Maxim MAX11100 driver
On 02/01/17 09:19, jacopo mondi wrote: > Hi Jonathan, >thanks for review > > On 30/12/2016 17:31, Jonathan Cameron wrote: >> On 14/12/16 12:00, jac...@jmondi.org wrote: >>> Hello Peter, >>>thanks for review >>> >>> On 13/12/2016 21:33, Peter Meerwald-Stadler wrote: > Add IIO driver for Maxim MAX11100 single-channel ADC. > Add DT bindings documentation. some more comments > Signed-off-by: Jacopo Mondi > --- > > v1 -> v2: > - incorporated pmeerw's review comments > - retrieve vref from dts and use that to convert read_raw result > to mV > - add device tree bindings documentation > > --- > .../devicetree/bindings/iio/adc/max11100.txt | 17 +++ > drivers/iio/adc/Kconfig| 9 ++ > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/max11100.c | 166 > + > 4 files changed, 193 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iio/adc/max11100.txt > create mode 100644 drivers/iio/adc/max11100.c > > diff --git a/Documentation/devicetree/bindings/iio/adc/max11100.txt > b/Documentation/devicetree/bindings/iio/adc/max11100.txt > new file mode 100644 > index 000..6877c11 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/adc/max11100.txt > @@ -0,0 +1,17 @@ > +* Maxim max11100 Analog to Digital Converter (ADC) > + > +Required properties: > + - compatible: Should be "maxim,max11100" > + - vref-supply: phandle to the regulator that provides reference voltage > + > +Optional properties: > + - spi-max-frequency: SPI maximum frequency > + > +Example: > + > +adc0: max11100@0 { > +compatible = "maxim,max11100"; > +vref-supply = <&adc0_vref>; > +spi-max-frequency = <24>; > +}; > + > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index 99c0514..a909484 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -285,6 +285,15 @@ config MAX1027 >To compile this driver as a module, choose M here: the module will > be >called max1027. > > +config MAX11100 > +tristate "Maxim max11100 ADC driver" > +depends on SPI SPI_MASTER is more precise I think > +help > + Say yes here to build support for Maxim max11100 SPI ADC > + > + To compile this driver as a module, choose M here: the module will > be > + called max11100. > + > config MAX1363 > tristate "Maxim max1363 ADC driver" > depends on I2C > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index 7a40c04..1463044 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -29,6 +29,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o > obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o > obj-$(CONFIG_LTC2485) += ltc2485.o > obj-$(CONFIG_MAX1027) += max1027.o > +obj-$(CONFIG_MAX11100) += max11100.o > obj-$(CONFIG_MAX1363) += max1363.o > obj-$(CONFIG_MCP320X) += mcp320x.o > obj-$(CONFIG_MCP3422) += mcp3422.o > diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c > new file mode 100644 > index 000..f372ad8 > --- /dev/null > +++ b/drivers/iio/adc/max11100.c > @@ -0,0 +1,166 @@ > +/* > + * iio/adc/max11100.c > + * Maxim max11100 ADC Driver with IIO interface > + * > + * Copyright (C) 2016 Renesas Electronics Corporation > + * Copyright (C) 2016 Jacopo Mondi > + * > + * 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 > + * published by the Free Software Foundation. > + */ > +#include > +#include > +#include > +#include > +#include > + > +#include > +#include > +#include > + > +/* > + * LSB is the ADC single digital step > + * 1 LSB = (vref / 2 ^ 16) > + * AIN = (DIN * LSB) > + */ > +#define MAX11100_LSB_DIV(1 << 16) > +#define MAX11100_LSB(vref) (vref / MAX11100_LSB_DIV) maybe parenthesis around vref > + > +struct max11100_state { > +const struct max11100_chip_desc *desc; > +struct spi_device *spi; > +int vref_uv; > +struct mutex lock; > +}; > + > +static struct iio_chan_spec max11100_channels[] = { > +{ /* [0] */ > +.type = IIO_VOLTAGE, > +.scan_type = { scan_type not needed since driver does not support buffered reads > +.sign = 'u', > +.realbits = 16, > +.storagebits = 24, > +.shift =