* [PATCH v3 0/2] Maxim MAX1241 driver
@ 2020-03-19 16:29 Alexandru Lazar
2020-03-19 16:29 ` [PATCH v3 1/2] iio: adc: Add " Alexandru Lazar
` (2 more replies)
0 siblings, 3 replies; 9+ messages in thread
From: Alexandru Lazar @ 2020-03-19 16:29 UTC (permalink / raw)
To: linux-iio
Cc: jic23, knaack.h, lars, pmeerw, robh+dt, mark.rutland, Alexandru Lazar
A silly typo found its way into the previous version of this patch
series. Fortunately, Alexandru Ardelean spotted it. I'm a little
embarrassed to show my face in public right now -- thankfully I'm
staying home these days anyway.
Other than the Kconfig text (which claimed this module was named max1118
-- like I said, I wear my code monkey badge with pride...) nothing's
changed since the last version. For reference, the last version is here:
https://lore.kernel.org/linux-iio/20200318202837.512428-1-alazar@startmail.com/
Thanks!
Alex
Alexandru Lazar (2):
iio: adc: Add MAX1241 driver
dt-bindings: iio: adc: Add MAX1241 device tree bindings in
documentation
.../bindings/iio/adc/maxim,max1241.yaml | 62 ++++++
drivers/iio/adc/Kconfig | 10 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/max1241.c | 206 ++++++++++++++++++
4 files changed, 279 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml
create mode 100644 drivers/iio/adc/max1241.c
--
2.25.2
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v3 1/2] iio: adc: Add MAX1241 driver
2020-03-19 16:29 [PATCH v3 0/2] Maxim MAX1241 driver Alexandru Lazar
@ 2020-03-19 16:29 ` Alexandru Lazar
2020-03-20 7:06 ` Ardelean, Alexandru
2020-03-19 16:29 ` [PATCH v3 2/2] dt-bindings: iio: adc: Add MAX1241 device tree bindings in documentation Alexandru Lazar
2020-03-20 7:02 ` [PATCH v3 0/2] Maxim MAX1241 driver Ardelean, Alexandru
2 siblings, 1 reply; 9+ messages in thread
From: Alexandru Lazar @ 2020-03-19 16:29 UTC (permalink / raw)
To: linux-iio
Cc: jic23, knaack.h, lars, pmeerw, robh+dt, mark.rutland, Alexandru Lazar
Add driver for the Maxim MAX1241 12-bit, single-channel ADC. The driver
includes support for this device's low-power operation mode.
Signed-off-by: Alexandru Lazar <alazar@startmail.com>
---
drivers/iio/adc/Kconfig | 10 ++
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/max1241.c | 206 ++++++++++++++++++++++++++++++++++++++
3 files changed, 217 insertions(+)
create mode 100644 drivers/iio/adc/max1241.c
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 5d8540b7b427..55f6462cd93f 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -566,6 +566,16 @@ config MAX1118
To compile this driver as a module, choose M here: the module will be
called max1118.
+config MAX1241
+ tristate "Maxim max1241 ADC driver"
+ depends on SPI_MASTER
+ help
+ Say yes here to build support for Maxim max1241 12-bit, single-channel
+ ADC.
+
+ To compile this driver as a module, choose M here: the module will be
+ called max1241.
+
config MAX1363
tristate "Maxim max1363 ADC driver"
depends on I2C
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index a1f1fbec0f87..37d6f17559dc 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -54,6 +54,7 @@ obj-$(CONFIG_LTC2497) += ltc2497.o
obj-$(CONFIG_MAX1027) += max1027.o
obj-$(CONFIG_MAX11100) += max11100.o
obj-$(CONFIG_MAX1118) += max1118.o
+obj-$(CONFIG_MAX1241) += max1241.o
obj-$(CONFIG_MAX1363) += max1363.o
obj-$(CONFIG_MAX9611) += max9611.o
obj-$(CONFIG_MCP320X) += mcp320x.o
diff --git a/drivers/iio/adc/max1241.c b/drivers/iio/adc/max1241.c
new file mode 100644
index 000000000000..0278510ec346
--- /dev/null
+++ b/drivers/iio/adc/max1241.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MAX1241 low-power, 12-bit serial ADC
+ *
+ * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf
+ */
+
+#include <linux/regulator/consumer.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+
+#define MAX1241_VAL_MASK 0xFFF
+#define MAX1241_SHDN_DELAY_USEC 4
+
+enum max1241_id {
+ max1241,
+};
+
+struct max1241 {
+ struct spi_device *spi;
+ struct mutex lock;
+ struct regulator *reg;
+ struct gpio_desc *shdn;
+
+ __be16 data ____cacheline_aligned;
+};
+
+static const struct iio_chan_spec max1241_channels[] = {
+ {
+ .type = IIO_VOLTAGE,
+ .indexed = 1,
+ .channel = 0,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 12,
+ .storagebits = 16,
+ },
+ },
+};
+
+static int max1241_read(struct max1241 *adc)
+{
+ struct spi_transfer xfers[] = {
+ /*
+ * Begin conversion by bringing /CS low for at least
+ * tconv us.
+ */
+ {
+ .len = 0,
+ .delay.value = 8,
+ .delay.unit = SPI_DELAY_UNIT_USECS,
+ },
+ /*
+ * Then read two bytes of data in our RX buffer.
+ */
+ {
+ .rx_buf = &adc->data,
+ .len = 2,
+ },
+ };
+
+ return spi_sync_transfer(adc->spi, xfers, ARRAY_SIZE(xfers));
+}
+
+static int max1241_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ int ret, vref_uV;
+ struct max1241 *adc = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&adc->lock);
+
+ if (adc->shdn) {
+ gpiod_set_value(adc->shdn, 0);
+ udelay(MAX1241_SHDN_DELAY_USEC);
+ }
+
+ ret = max1241_read(adc);
+
+ if (adc->shdn)
+ gpiod_set_value(adc->shdn, 1);
+
+ if (ret) {
+ mutex_unlock(&adc->lock);
+ return ret;
+ }
+
+ *val = (be16_to_cpu(adc->data) >> 3) & MAX1241_VAL_MASK;
+
+ mutex_unlock(&adc->lock);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ vref_uV = regulator_get_voltage(adc->reg);
+
+ if (vref_uV < 0)
+ return vref_uV;
+
+ *val = vref_uV / 1000;
+ *val2 = 12;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info max1241_info = {
+ .read_raw = max1241_read_raw,
+};
+
+static void max1241_disable_reg_action(void *data)
+{
+ struct max1241 *adc = data;
+ int err;
+
+ err = regulator_disable(adc->reg);
+ if (err)
+ dev_err(&adc->spi->dev, "could not disable reference regulator.\n");
+}
+
+static int max1241_probe(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev;
+ struct max1241 *adc;
+ int ret = 0;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ adc = iio_priv(indio_dev);
+ adc->spi = spi;
+ mutex_init(&adc->lock);
+
+ spi_set_drvdata(spi, indio_dev);
+
+ adc->reg = devm_regulator_get(&spi->dev, "vref");
+ if (IS_ERR(adc->reg)) {
+ dev_err(&spi->dev, "failed to get vref regulator\n");
+ return PTR_ERR(adc->reg);
+ }
+
+ ret = regulator_enable(adc->reg);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(&spi->dev, max1241_disable_reg_action,
+ adc);
+ if (ret) {
+ dev_err(&spi->dev, "could not set up regulator cleanup action!\n");
+ return ret;
+ }
+
+ adc->shdn = devm_gpiod_get_optional(&spi->dev, "shdn", GPIOD_OUT_HIGH);
+
+ if (IS_ERR(adc->shdn))
+ return PTR_ERR(adc->shdn);
+
+ if (!adc->shdn)
+ dev_dbg(&spi->dev, "no shdn pin passed, low-power mode disabled");
+ else
+ dev_dbg(&spi->dev, "shdn pin passed, low-power mode enabled");
+
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->info = &max1241_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = max1241_channels;
+ indio_dev->num_channels = ARRAY_SIZE(max1241_channels);
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct spi_device_id max1241_id[] = {
+ { "max1241", max1241 },
+ {},
+};
+
+static const struct of_device_id max1241_dt_ids[] = {
+ { .compatible = "maxim,max1241" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, max1241_dt_ids);
+
+static struct spi_driver max1241_spi_driver = {
+ .driver = {
+ .name = "max1241",
+ .of_match_table = max1241_dt_ids,
+ },
+ .probe = max1241_probe,
+ .id_table = max1241_id,
+};
+module_spi_driver(max1241_spi_driver);
+
+MODULE_AUTHOR("Alexandru Lazar <alazar@startmail.com>");
+MODULE_DESCRIPTION("MAX1241 ADC driver");
+MODULE_LICENSE("GPL v2");
--
2.25.2
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v3 2/2] dt-bindings: iio: adc: Add MAX1241 device tree bindings in documentation
2020-03-19 16:29 [PATCH v3 0/2] Maxim MAX1241 driver Alexandru Lazar
2020-03-19 16:29 ` [PATCH v3 1/2] iio: adc: Add " Alexandru Lazar
@ 2020-03-19 16:29 ` Alexandru Lazar
2020-03-20 7:12 ` Ardelean, Alexandru
2020-03-20 7:02 ` [PATCH v3 0/2] Maxim MAX1241 driver Ardelean, Alexandru
2 siblings, 1 reply; 9+ messages in thread
From: Alexandru Lazar @ 2020-03-19 16:29 UTC (permalink / raw)
To: linux-iio
Cc: jic23, knaack.h, lars, pmeerw, robh+dt, mark.rutland, Alexandru Lazar
Add device-tree bindings documentation for the MAX1241 device driver.
Signed-off-by: Alexandru Lazar <alazar@startmail.com>
---
.../bindings/iio/adc/maxim,max1241.yaml | 62 +++++++++++++++++++
1 file changed, 62 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml
diff --git a/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml b/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml
new file mode 100644
index 000000000000..28c73ed795aa
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright 2020 Ioan-Alexandru Lazar
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/maxim,max1241.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Maxim MAX1241 12-bit, single-channel analog to digital converter
+
+maintainers:
+ - Ioan-Alexandru Lazar <alazar@startmail.com>
+
+description: |
+ Bindings for the max1241 12-bit, single-channel ADC device. This
+ driver supports voltage reading and can optionally be configured for
+ power-down mode operation. The datasheet can be found at:
+ https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf
+
+properties:
+ compatible:
+ enum:
+ - maxim,max1241
+
+ reg:
+ description: SPI chip select number for this device
+ maxItems: 1
+
+ vref-supply:
+ description:
+ Device tree identifier of the regulator that provides the external
+ reference voltage.
+ maxItems: 1
+
+ shdn-gpios:
+ description:
+ GPIO spec for the GPIO pin connected to the ADC's /SHDN pin. If
+ specified, the /SHDN pin will be asserted between conversions,
+ thus enabling power-down mode.
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+ - vref-supply
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ spi0 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ adc@0 {
+ compatible = "maxim,max1241";
+ reg = <0>;
+ vref-supply = <&vdd_3v3_reg>;
+ spi-max-frequency = <1000000>;
+ shdn-gpios = <&gpio 26 1>;
+ };
+ };
+
+
--
2.25.2
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v3 0/2] Maxim MAX1241 driver
2020-03-19 16:29 [PATCH v3 0/2] Maxim MAX1241 driver Alexandru Lazar
2020-03-19 16:29 ` [PATCH v3 1/2] iio: adc: Add " Alexandru Lazar
2020-03-19 16:29 ` [PATCH v3 2/2] dt-bindings: iio: adc: Add MAX1241 device tree bindings in documentation Alexandru Lazar
@ 2020-03-20 7:02 ` Ardelean, Alexandru
2 siblings, 0 replies; 9+ messages in thread
From: Ardelean, Alexandru @ 2020-03-20 7:02 UTC (permalink / raw)
To: alazar, linux-iio; +Cc: jic23, mark.rutland, knaack.h, lars, pmeerw, robh+dt
On Thu, 2020-03-19 at 18:29 +0200, Alexandru Lazar wrote:
> A silly typo found its way into the previous version of this patch
> series. Fortunately, Alexandru Ardelean spotted it. I'm a little
> embarrassed to show my face in public right now -- thankfully I'm
> staying home these days anyway.
I still win in embarrassment [getting embarrassed] contests.
>
> Other than the Kconfig text (which claimed this module was named max1118
> -- like I said, I wear my code monkey badge with pride...) nothing's
> changed since the last version. For reference, the last version is here:
>
> https://lore.kernel.org/linux-iio/20200318202837.512428-1-alazar@startmail.com/
>
For future patches: it's usually a good idea to include changelog in each
V2,3,4,N
Example:
https://lore.kernel.org/linux-iio/20200316155035.25500-1-alexandru.ardelean@analog.com/T/
[this one [of mine] got up-to V10 :p ; I'll admit I didn't do a good job right
from the start]
> Thanks!
>
> Alex
>
> Alexandru Lazar (2):
> iio: adc: Add MAX1241 driver
> dt-bindings: iio: adc: Add MAX1241 device tree bindings in
> documentation
>
> .../bindings/iio/adc/maxim,max1241.yaml | 62 ++++++
> drivers/iio/adc/Kconfig | 10 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/max1241.c | 206 ++++++++++++++++++
> 4 files changed, 279 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml
> create mode 100644 drivers/iio/adc/max1241.c
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v3 1/2] iio: adc: Add MAX1241 driver
2020-03-19 16:29 ` [PATCH v3 1/2] iio: adc: Add " Alexandru Lazar
@ 2020-03-20 7:06 ` Ardelean, Alexandru
2020-03-20 7:13 ` Ardelean, Alexandru
0 siblings, 1 reply; 9+ messages in thread
From: Ardelean, Alexandru @ 2020-03-20 7:06 UTC (permalink / raw)
To: alazar, linux-iio; +Cc: jic23, mark.rutland, knaack.h, lars, pmeerw, robh+dt
On Thu, 2020-03-19 at 18:29 +0200, Alexandru Lazar wrote:
> Add driver for the Maxim MAX1241 12-bit, single-channel ADC. The driver
> includes support for this device's low-power operation mode.
>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> Signed-off-by: Alexandru Lazar <alazar@startmail.com>
> ---
> drivers/iio/adc/Kconfig | 10 ++
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/max1241.c | 206 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 217 insertions(+)
> create mode 100644 drivers/iio/adc/max1241.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 5d8540b7b427..55f6462cd93f 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -566,6 +566,16 @@ config MAX1118
> To compile this driver as a module, choose M here: the module will be
> called max1118.
>
> +config MAX1241
> + tristate "Maxim max1241 ADC driver"
> + depends on SPI_MASTER
> + help
> + Say yes here to build support for Maxim max1241 12-bit, single-channel
> + ADC.
> +
> + To compile this driver as a module, choose M here: the module will be
> + called max1241.
> +
> config MAX1363
> tristate "Maxim max1363 ADC driver"
> depends on I2C
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index a1f1fbec0f87..37d6f17559dc 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -54,6 +54,7 @@ obj-$(CONFIG_LTC2497) += ltc2497.o
> obj-$(CONFIG_MAX1027) += max1027.o
> obj-$(CONFIG_MAX11100) += max11100.o
> obj-$(CONFIG_MAX1118) += max1118.o
> +obj-$(CONFIG_MAX1241) += max1241.o
> obj-$(CONFIG_MAX1363) += max1363.o
> obj-$(CONFIG_MAX9611) += max9611.o
> obj-$(CONFIG_MCP320X) += mcp320x.o
> diff --git a/drivers/iio/adc/max1241.c b/drivers/iio/adc/max1241.c
> new file mode 100644
> index 000000000000..0278510ec346
> --- /dev/null
> +++ b/drivers/iio/adc/max1241.c
> @@ -0,0 +1,206 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * MAX1241 low-power, 12-bit serial ADC
> + *
> + * Datasheet:
> https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf
> + */
> +
> +#include <linux/regulator/consumer.h>
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/module.h>
> +#include <linux/spi/spi.h>
> +
> +#define MAX1241_VAL_MASK 0xFFF
> +#define MAX1241_SHDN_DELAY_USEC 4
> +
> +enum max1241_id {
> + max1241,
> +};
> +
> +struct max1241 {
> + struct spi_device *spi;
> + struct mutex lock;
> + struct regulator *reg;
> + struct gpio_desc *shdn;
> +
> + __be16 data ____cacheline_aligned;
> +};
> +
> +static const struct iio_chan_spec max1241_channels[] = {
> + {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .channel = 0,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE),
> + .scan_index = 0,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 12,
> + .storagebits = 16,
> + },
> + },
> +};
> +
> +static int max1241_read(struct max1241 *adc)
> +{
> + struct spi_transfer xfers[] = {
> + /*
> + * Begin conversion by bringing /CS low for at least
> + * tconv us.
> + */
> + {
> + .len = 0,
> + .delay.value = 8,
> + .delay.unit = SPI_DELAY_UNIT_USECS,
> + },
> + /*
> + * Then read two bytes of data in our RX buffer.
> + */
> + {
> + .rx_buf = &adc->data,
> + .len = 2,
> + },
> + };
> +
> + return spi_sync_transfer(adc->spi, xfers, ARRAY_SIZE(xfers));
> +}
> +
> +static int max1241_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + int ret, vref_uV;
> + struct max1241 *adc = iio_priv(indio_dev);
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + mutex_lock(&adc->lock);
> +
> + if (adc->shdn) {
> + gpiod_set_value(adc->shdn, 0);
> + udelay(MAX1241_SHDN_DELAY_USEC);
> + }
> +
> + ret = max1241_read(adc);
> +
> + if (adc->shdn)
> + gpiod_set_value(adc->shdn, 1);
> +
> + if (ret) {
> + mutex_unlock(&adc->lock);
> + return ret;
> + }
> +
> + *val = (be16_to_cpu(adc->data) >> 3) & MAX1241_VAL_MASK;
> +
> + mutex_unlock(&adc->lock);
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + vref_uV = regulator_get_voltage(adc->reg);
> +
> + if (vref_uV < 0)
> + return vref_uV;
> +
> + *val = vref_uV / 1000;
> + *val2 = 12;
> +
> + return IIO_VAL_FRACTIONAL_LOG2;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static const struct iio_info max1241_info = {
> + .read_raw = max1241_read_raw,
> +};
> +
> +static void max1241_disable_reg_action(void *data)
> +{
> + struct max1241 *adc = data;
> + int err;
> +
> + err = regulator_disable(adc->reg);
> + if (err)
> + dev_err(&adc->spi->dev, "could not disable reference
> regulator.\n");
> +}
> +
> +static int max1241_probe(struct spi_device *spi)
> +{
> + struct iio_dev *indio_dev;
> + struct max1241 *adc;
> + int ret = 0;
> +
> + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + adc = iio_priv(indio_dev);
> + adc->spi = spi;
> + mutex_init(&adc->lock);
> +
> + spi_set_drvdata(spi, indio_dev);
> +
> + adc->reg = devm_regulator_get(&spi->dev, "vref");
> + if (IS_ERR(adc->reg)) {
> + dev_err(&spi->dev, "failed to get vref regulator\n");
> + return PTR_ERR(adc->reg);
> + }
> +
> + ret = regulator_enable(adc->reg);
> + if (ret)
> + return ret;
> +
> + ret = devm_add_action_or_reset(&spi->dev, max1241_disable_reg_action,
> + adc);
> + if (ret) {
> + dev_err(&spi->dev, "could not set up regulator cleanup
> action!\n");
> + return ret;
> + }
> +
> + adc->shdn = devm_gpiod_get_optional(&spi->dev, "shdn", GPIOD_OUT_HIGH);
> +
> + if (IS_ERR(adc->shdn))
> + return PTR_ERR(adc->shdn);
> +
> + if (!adc->shdn)
> + dev_dbg(&spi->dev, "no shdn pin passed, low-power mode
> disabled");
> + else
> + dev_dbg(&spi->dev, "shdn pin passed, low-power mode enabled");
> +
> + indio_dev->name = spi_get_device_id(spi)->name;
> + indio_dev->dev.parent = &spi->dev;
> + indio_dev->info = &max1241_info;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->channels = max1241_channels;
> + indio_dev->num_channels = ARRAY_SIZE(max1241_channels);
> +
> + return devm_iio_device_register(&spi->dev, indio_dev);
> +}
> +
> +static const struct spi_device_id max1241_id[] = {
> + { "max1241", max1241 },
> + {},
> +};
> +
> +static const struct of_device_id max1241_dt_ids[] = {
> + { .compatible = "maxim,max1241" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, max1241_dt_ids);
> +
> +static struct spi_driver max1241_spi_driver = {
> + .driver = {
> + .name = "max1241",
> + .of_match_table = max1241_dt_ids,
> + },
> + .probe = max1241_probe,
> + .id_table = max1241_id,
> +};
> +module_spi_driver(max1241_spi_driver);
> +
> +MODULE_AUTHOR("Alexandru Lazar <alazar@startmail.com>");
> +MODULE_DESCRIPTION("MAX1241 ADC driver");
> +MODULE_LICENSE("GPL v2");
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v3 2/2] dt-bindings: iio: adc: Add MAX1241 device tree bindings in documentation
2020-03-19 16:29 ` [PATCH v3 2/2] dt-bindings: iio: adc: Add MAX1241 device tree bindings in documentation Alexandru Lazar
@ 2020-03-20 7:12 ` Ardelean, Alexandru
2020-03-20 8:33 ` Alexandru Lazar
0 siblings, 1 reply; 9+ messages in thread
From: Ardelean, Alexandru @ 2020-03-20 7:12 UTC (permalink / raw)
To: alazar, linux-iio; +Cc: jic23, mark.rutland, knaack.h, lars, pmeerw, robh+dt
On Thu, 2020-03-19 at 18:29 +0200, Alexandru Lazar wrote:
> Add device-tree bindings documentation for the MAX1241 device driver.
>
> Signed-off-by: Alexandru Lazar <alazar@startmail.com>
> ---
> .../bindings/iio/adc/maxim,max1241.yaml | 62 +++++++++++++++++++
> 1 file changed, 62 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml
>
> diff --git a/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml
> b/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml
> new file mode 100644
> index 000000000000..28c73ed795aa
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/maxim,max1241.yaml
> @@ -0,0 +1,62 @@
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright 2020 Ioan-Alexandru Lazar
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/maxim,max1241.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Maxim MAX1241 12-bit, single-channel analog to digital converter
> +
> +maintainers:
> + - Ioan-Alexandru Lazar <alazar@startmail.com>
> +
> +description: |
> + Bindings for the max1241 12-bit, single-channel ADC device. This
> + driver supports voltage reading and can optionally be configured for
> + power-down mode operation. The datasheet can be found at:
> + https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf
> +
> +properties:
> + compatible:
> + enum:
> + - maxim,max1241
> +
> + reg:
> + description: SPI chip select number for this device
Rob will probably complain that you don't need to document[add description] to
standard attributes [like SPI's 'reg' parameter]
Just listing it here, should be sufficient. So, you can drop the description.
> + maxItems: 1
> +
> + vref-supply:
> + description:
> + Device tree identifier of the regulator that provides the external
> + reference voltage.
> + maxItems: 1
> +
> + shdn-gpios:
> + description:
> + GPIO spec for the GPIO pin connected to the ADC's /SHDN pin. If
> + specified, the /SHDN pin will be asserted between conversions,
> + thus enabling power-down mode.
> + maxItems: 1
> +
> +required:
> + - compatible
> + - reg
> + - vref-supply
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> + spi0 {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + adc@0 {
> + compatible = "maxim,max1241";
> + reg = <0>;
> + vref-supply = <&vdd_3v3_reg>;
> + spi-max-frequency = <1000000>;
> + shdn-gpios = <&gpio 26 1>;
> + };
> + };
> +
> +
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v3 1/2] iio: adc: Add MAX1241 driver
2020-03-20 7:06 ` Ardelean, Alexandru
@ 2020-03-20 7:13 ` Ardelean, Alexandru
0 siblings, 0 replies; 9+ messages in thread
From: Ardelean, Alexandru @ 2020-03-20 7:13 UTC (permalink / raw)
To: alazar, linux-iio; +Cc: robh+dt, jic23, mark.rutland, knaack.h, pmeerw, lars
On Fri, 2020-03-20 at 07:06 +0000, Ardelean, Alexandru wrote:
> [External]
>
> On Thu, 2020-03-19 at 18:29 +0200, Alexandru Lazar wrote:
> > Add driver for the Maxim MAX1241 12-bit, single-channel ADC. The driver
> > includes support for this device's low-power operation mode.
> >
>
> Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
before I forget;
if you do a V4 [or above] you can add my Reviewed-by tag to this patch
>
> > Signed-off-by: Alexandru Lazar <alazar@startmail.com>
> > ---
> > drivers/iio/adc/Kconfig | 10 ++
> > drivers/iio/adc/Makefile | 1 +
> > drivers/iio/adc/max1241.c | 206 ++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 217 insertions(+)
> > create mode 100644 drivers/iio/adc/max1241.c
> >
> > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> > index 5d8540b7b427..55f6462cd93f 100644
> > --- a/drivers/iio/adc/Kconfig
> > +++ b/drivers/iio/adc/Kconfig
> > @@ -566,6 +566,16 @@ config MAX1118
> > To compile this driver as a module, choose M here: the module will be
> > called max1118.
> >
> > +config MAX1241
> > + tristate "Maxim max1241 ADC driver"
> > + depends on SPI_MASTER
> > + help
> > + Say yes here to build support for Maxim max1241 12-bit, single-channel
> > + ADC.
> > +
> > + To compile this driver as a module, choose M here: the module will be
> > + called max1241.
> > +
> > config MAX1363
> > tristate "Maxim max1363 ADC driver"
> > depends on I2C
> > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> > index a1f1fbec0f87..37d6f17559dc 100644
> > --- a/drivers/iio/adc/Makefile
> > +++ b/drivers/iio/adc/Makefile
> > @@ -54,6 +54,7 @@ obj-$(CONFIG_LTC2497) += ltc2497.o
> > obj-$(CONFIG_MAX1027) += max1027.o
> > obj-$(CONFIG_MAX11100) += max11100.o
> > obj-$(CONFIG_MAX1118) += max1118.o
> > +obj-$(CONFIG_MAX1241) += max1241.o
> > obj-$(CONFIG_MAX1363) += max1363.o
> > obj-$(CONFIG_MAX9611) += max9611.o
> > obj-$(CONFIG_MCP320X) += mcp320x.o
> > diff --git a/drivers/iio/adc/max1241.c b/drivers/iio/adc/max1241.c
> > new file mode 100644
> > index 000000000000..0278510ec346
> > --- /dev/null
> > +++ b/drivers/iio/adc/max1241.c
> > @@ -0,0 +1,206 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * MAX1241 low-power, 12-bit serial ADC
> > + *
> > + * Datasheet:
> > https://datasheets.maximintegrated.com/en/ds/MAX1240-MAX1241.pdf
> > + */
> > +
> > +#include <linux/regulator/consumer.h>
> > +#include <linux/delay.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/iio/iio.h>
> > +#include <linux/module.h>
> > +#include <linux/spi/spi.h>
> > +
> > +#define MAX1241_VAL_MASK 0xFFF
> > +#define MAX1241_SHDN_DELAY_USEC 4
> > +
> > +enum max1241_id {
> > + max1241,
> > +};
> > +
> > +struct max1241 {
> > + struct spi_device *spi;
> > + struct mutex lock;
> > + struct regulator *reg;
> > + struct gpio_desc *shdn;
> > +
> > + __be16 data ____cacheline_aligned;
> > +};
> > +
> > +static const struct iio_chan_spec max1241_channels[] = {
> > + {
> > + .type = IIO_VOLTAGE,
> > + .indexed = 1,
> > + .channel = 0,
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> > + BIT(IIO_CHAN_INFO_SCALE),
> > + .scan_index = 0,
> > + .scan_type = {
> > + .sign = 'u',
> > + .realbits = 12,
> > + .storagebits = 16,
> > + },
> > + },
> > +};
> > +
> > +static int max1241_read(struct max1241 *adc)
> > +{
> > + struct spi_transfer xfers[] = {
> > + /*
> > + * Begin conversion by bringing /CS low for at least
> > + * tconv us.
> > + */
> > + {
> > + .len = 0,
> > + .delay.value = 8,
> > + .delay.unit = SPI_DELAY_UNIT_USECS,
> > + },
> > + /*
> > + * Then read two bytes of data in our RX buffer.
> > + */
> > + {
> > + .rx_buf = &adc->data,
> > + .len = 2,
> > + },
> > + };
> > +
> > + return spi_sync_transfer(adc->spi, xfers, ARRAY_SIZE(xfers));
> > +}
> > +
> > +static int max1241_read_raw(struct iio_dev *indio_dev,
> > + struct iio_chan_spec const *chan,
> > + int *val, int *val2, long mask)
> > +{
> > + int ret, vref_uV;
> > + struct max1241 *adc = iio_priv(indio_dev);
> > +
> > + switch (mask) {
> > + case IIO_CHAN_INFO_RAW:
> > + mutex_lock(&adc->lock);
> > +
> > + if (adc->shdn) {
> > + gpiod_set_value(adc->shdn, 0);
> > + udelay(MAX1241_SHDN_DELAY_USEC);
> > + }
> > +
> > + ret = max1241_read(adc);
> > +
> > + if (adc->shdn)
> > + gpiod_set_value(adc->shdn, 1);
> > +
> > + if (ret) {
> > + mutex_unlock(&adc->lock);
> > + return ret;
> > + }
> > +
> > + *val = (be16_to_cpu(adc->data) >> 3) & MAX1241_VAL_MASK;
> > +
> > + mutex_unlock(&adc->lock);
> > + return IIO_VAL_INT;
> > + case IIO_CHAN_INFO_SCALE:
> > + vref_uV = regulator_get_voltage(adc->reg);
> > +
> > + if (vref_uV < 0)
> > + return vref_uV;
> > +
> > + *val = vref_uV / 1000;
> > + *val2 = 12;
> > +
> > + return IIO_VAL_FRACTIONAL_LOG2;
> > + default:
> > + return -EINVAL;
> > + }
> > +}
> > +
> > +static const struct iio_info max1241_info = {
> > + .read_raw = max1241_read_raw,
> > +};
> > +
> > +static void max1241_disable_reg_action(void *data)
> > +{
> > + struct max1241 *adc = data;
> > + int err;
> > +
> > + err = regulator_disable(adc->reg);
> > + if (err)
> > + dev_err(&adc->spi->dev, "could not disable reference
> > regulator.\n");
> > +}
> > +
> > +static int max1241_probe(struct spi_device *spi)
> > +{
> > + struct iio_dev *indio_dev;
> > + struct max1241 *adc;
> > + int ret = 0;
> > +
> > + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
> > + if (!indio_dev)
> > + return -ENOMEM;
> > +
> > + adc = iio_priv(indio_dev);
> > + adc->spi = spi;
> > + mutex_init(&adc->lock);
> > +
> > + spi_set_drvdata(spi, indio_dev);
> > +
> > + adc->reg = devm_regulator_get(&spi->dev, "vref");
> > + if (IS_ERR(adc->reg)) {
> > + dev_err(&spi->dev, "failed to get vref regulator\n");
> > + return PTR_ERR(adc->reg);
> > + }
> > +
> > + ret = regulator_enable(adc->reg);
> > + if (ret)
> > + return ret;
> > +
> > + ret = devm_add_action_or_reset(&spi->dev, max1241_disable_reg_action,
> > + adc);
> > + if (ret) {
> > + dev_err(&spi->dev, "could not set up regulator cleanup
> > action!\n");
> > + return ret;
> > + }
> > +
> > + adc->shdn = devm_gpiod_get_optional(&spi->dev, "shdn", GPIOD_OUT_HIGH);
> > +
> > + if (IS_ERR(adc->shdn))
> > + return PTR_ERR(adc->shdn);
> > +
> > + if (!adc->shdn)
> > + dev_dbg(&spi->dev, "no shdn pin passed, low-power mode
> > disabled");
> > + else
> > + dev_dbg(&spi->dev, "shdn pin passed, low-power mode enabled");
> > +
> > + indio_dev->name = spi_get_device_id(spi)->name;
> > + indio_dev->dev.parent = &spi->dev;
> > + indio_dev->info = &max1241_info;
> > + indio_dev->modes = INDIO_DIRECT_MODE;
> > + indio_dev->channels = max1241_channels;
> > + indio_dev->num_channels = ARRAY_SIZE(max1241_channels);
> > +
> > + return devm_iio_device_register(&spi->dev, indio_dev);
> > +}
> > +
> > +static const struct spi_device_id max1241_id[] = {
> > + { "max1241", max1241 },
> > + {},
> > +};
> > +
> > +static const struct of_device_id max1241_dt_ids[] = {
> > + { .compatible = "maxim,max1241" },
> > + {},
> > +};
> > +MODULE_DEVICE_TABLE(of, max1241_dt_ids);
> > +
> > +static struct spi_driver max1241_spi_driver = {
> > + .driver = {
> > + .name = "max1241",
> > + .of_match_table = max1241_dt_ids,
> > + },
> > + .probe = max1241_probe,
> > + .id_table = max1241_id,
> > +};
> > +module_spi_driver(max1241_spi_driver);
> > +
> > +MODULE_AUTHOR("Alexandru Lazar <alazar@startmail.com>");
> > +MODULE_DESCRIPTION("MAX1241 ADC driver");
> > +MODULE_LICENSE("GPL v2");
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v3 2/2] dt-bindings: iio: adc: Add MAX1241 device tree bindings in documentation
2020-03-20 7:12 ` Ardelean, Alexandru
@ 2020-03-20 8:33 ` Alexandru Lazar
2020-03-20 8:45 ` Ardelean, Alexandru
0 siblings, 1 reply; 9+ messages in thread
From: Alexandru Lazar @ 2020-03-20 8:33 UTC (permalink / raw)
To: Ardelean, Alexandru
Cc: linux-iio, jic23, mark.rutland, knaack.h, lars, pmeerw, robh+dt
> > + reg:
> > + description: SPI chip select number for this device
>
> Rob will probably complain that you don't need to document[add description] to
> standard attributes [like SPI's 'reg' parameter]
> Just listing it here, should be sufficient. So, you can drop the
> description.
Makes sense -- should've thought of it, considering I dropped the doc
for spi-frequency as well. My brain is still wired to the non-standard
txt docs it seems, sorry!
I'm going to make a v4 for this (I think I need to reorder the patch
series anyway -- the dt-bindings should come first) and Cc: the
dt-bindings list with as well.
Thanks again for all your help!
Best regards,
Alex
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v3 2/2] dt-bindings: iio: adc: Add MAX1241 device tree bindings in documentation
2020-03-20 8:33 ` Alexandru Lazar
@ 2020-03-20 8:45 ` Ardelean, Alexandru
0 siblings, 0 replies; 9+ messages in thread
From: Ardelean, Alexandru @ 2020-03-20 8:45 UTC (permalink / raw)
To: alazar; +Cc: pmeerw, robh+dt, jic23, mark.rutland, linux-iio, lars, knaack.h
On Fri, 2020-03-20 at 10:33 +0200, Alexandru Lazar wrote:
> [External]
>
> > > + reg:
> > > + description: SPI chip select number for this device
> >
> > Rob will probably complain that you don't need to document[add description]
> > to
> > standard attributes [like SPI's 'reg' parameter]
> > Just listing it here, should be sufficient. So, you can drop the
> > description.
>
> Makes sense -- should've thought of it, considering I dropped the doc
> for spi-frequency as well. My brain is still wired to the non-standard
> txt docs it seems, sorry!
>
I think many people aren't yet super-comfortable with the new yaml format, which
probably makes Rob's life a bit difficult.
I guess it should become easier once version 5.4+ becomes more popular.
> I'm going to make a v4 for this (I think I need to reorder the patch
> series anyway -- the dt-bindings should come first) and Cc: the
> dt-bindings list with as well.
The order of the bindings vs code is a bit relaxed [atm]. But may become more
strict [later at some point]. I think the official version is bindings-first &
driver-next, but it's still accepted to do it the other way around.
>
> Thanks again for all your help!
>
> Best regards,
> Alex
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2020-03-20 8:46 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-19 16:29 [PATCH v3 0/2] Maxim MAX1241 driver Alexandru Lazar
2020-03-19 16:29 ` [PATCH v3 1/2] iio: adc: Add " Alexandru Lazar
2020-03-20 7:06 ` Ardelean, Alexandru
2020-03-20 7:13 ` Ardelean, Alexandru
2020-03-19 16:29 ` [PATCH v3 2/2] dt-bindings: iio: adc: Add MAX1241 device tree bindings in documentation Alexandru Lazar
2020-03-20 7:12 ` Ardelean, Alexandru
2020-03-20 8:33 ` Alexandru Lazar
2020-03-20 8:45 ` Ardelean, Alexandru
2020-03-20 7:02 ` [PATCH v3 0/2] Maxim MAX1241 driver Ardelean, Alexandru
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