Re: [PATCH] iio: adc: add driver for ti adc081s/adc101s/adc121s

From: Milan Stevanovic
Date: Mon Dec 25 2017 - 15:43:00 EST

On 12/25/2017 03:21 PM, Philippe Ombredanne wrote:
On Sun, Dec 24, 2017 at 8:02 PM, Milan Stevanovic
<milan.o.stevanovic@xxxxxxxxx> wrote:
On 12/23/2017 03:13 PM, Philippe Ombredanne wrote:
Milan,

On Sat, Dec 23, 2017 at 12:19 AM, Milan Stevanovic
<milan.o.stevanovic@xxxxxxxxx> wrote:
Signed-off-by: Milan Stevanovic <milan.o.stevanovic@xxxxxxxxx>
<snip>

May be it is just me, but you may be missing a commit message?

<snip>
Yes... Sorry I missed this
--- /dev/null
+++ b/drivers/iio/adc/ti-adc081s.c
@@ -0,0 +1,239 @@
+/*
+ * TI ADC081S/ADC101S/ADC121S 8/10/12-bit ADC driver
+ *
+ *
+ * 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.
Could you consider using an SPDX tag here as documented by Thomas in
this patch set [1] ?
This is the new thing for this end of of year and a must have for 2018!

[1] https://lkml.org/lkml/2017/12/4/934
Thanks for this... I added it...

Best regards
Milan

From 039f53aa702bd524e53c61b0365d048e2624ef02 Mon Sep 17 00:00:00 2001
From: Milan Stevanovic <milan.o.stevanovic@xxxxxxxxx>
Date: Sat, 23 Dec 2017 00:06:32 +0100
Subject: [PATCH v2] iio: adc: add driver for ti adc081s/adc101s/adc121s

Linux device driver for single-channel CMOS
8/10/12-bit analog-to-digital converter with a
high-speed serial interface.

Signed-off-by: Milan Stevanovic <milan.o.stevanovic@xxxxxxxxx>

Changes in v2:
- Add SPDX tag
- Add correct git commit message
<snip>

--- /dev/null
+++ b/drivers/iio/adc/ti-adc081s.c
@@ -0,0 +1,242 @@
+/*
+ * Released under the GPLv2 only.
+ * SPDX-License-Identifier: GPL-2.0
+ *
The SPDX tag should be on the first line using a C++ style comment
when in a .c file as explained in Thomas doc
And when using an SPDx id, do no repeat a license notice: this would
defeat the whole purpose of getting rid of boilerplate.

+// SPDX-License-Identifier: GPL-2.0
Thanks

Best regards
Milan

From 108841eb108275081958610f03d8c8b0da280666 Mon Sep 17 00:00:00 2001
From: Milan Stevanovic <milan.o.stevanovic@xxxxxxxxx>
Date: Sat, 23 Dec 2017 00:06:32 +0100
Subject: [PATCH v3] iio: adc: add driver for ti adc081s/adc101s/adc121s

Linux device driver for single-channel CMOS
8/10/12-bit analog-to-digital converter with a
high-speed serial interface.

Signed-off-by: Milan Stevanovic <milan.o.stevanovic@xxxxxxxxx>

Changes in v2:
- Add SPDX tag
- Add correct git commit message

Changes in v3:
- C++ style comment for SPDX
- update Kconfig file with name of devices
- Add device tree txt file
---
.../devicetree/bindings/iio/adc/ti-adc081s.txt | 18 ++
drivers/iio/adc/Kconfig | 10 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti-adc081s.c | 238 +++++++++++++++++++++
4 files changed, 267 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/ti-adc081s.txt
create mode 100644 drivers/iio/adc/ti-adc081s.c

diff --git a/Documentation/devicetree/bindings/iio/adc/ti-adc081s.txt b/Documentation/devicetree/bindings/iio/adc/ti-adc081s.txt
new file mode 100644
index 0000000..7d2a10d
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/ti-adc081s.txt
@@ -0,0 +1,18 @@
+* Texas Instruments' ADC081S/ADC101S/ADC121S
+
+Required properties:
+ - compatible: Should be one of
+ * "ti,adc081s"
+ * "ti,adc101s"
+ * "ti,adc121s"
+ - reg: spi chip select number for the device
+ - vref-supply: The regulator supply for ADC reference voltage
+ - spi-max-frequency: Max SPI frequency to use (< 400000)
+
+Example:
+adc@0 {
+ compatible = "ti,adc081s";
+ reg = <0>;
+ vref-supply = <&vdd_supply>;
+ spi-max-frequency = <200000>;
+};
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index ef86296..10366d6 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -701,6 +701,16 @@ config TI_ADC081C
This driver can also be built as a module. If so, the module will be
called ti-adc081c.
+config TI_ADC081S
+ tristate "Texas Instruments ADC081S/ADC101S/ADC121S family"
+ depends on SPI
+ help
+ If you say yes here you get support for Texas Instruments
+ ADC081S/ADC101S/ADC121S family ADC chips.
+
+ This driver can also be built as a module. If so, the module will be
+ called ti-adc081s.
+
config TI_ADC0832
tristate "Texas Instruments ADC0831/ADC0832/ADC0834/ADC0838"
depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 9572c10..020fecf 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -65,6 +65,7 @@ obj-$(CONFIG_SUN4I_GPADC) += sun4i-gpadc-iio.o
obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o
obj-$(CONFIG_STM32_ADC) += stm32-adc.o
obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
+obj-$(CONFIG_TI_ADC081S) += ti-adc081s.o
obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
obj-$(CONFIG_TI_ADC084S021) += ti-adc084s021.o
obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o
diff --git a/drivers/iio/adc/ti-adc081s.c b/drivers/iio/adc/ti-adc081s.c
new file mode 100644
index 0000000..e0db4fd
--- /dev/null
+++ b/drivers/iio/adc/ti-adc081s.c
@@ -0,0 +1,238 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TI ADC081S/ADC101S/ADC121S 8/10/12-bit ADC driver
+ *
+ * Linux device driver for single-channel CMOS
+ * 8/10/12-bit analog-to-digital converter with a
+ * high-speed serial interface.
+ *
+ * Datasheets:
+ * http://www.ti.com/lit/ds/symlink/adc081s021.pdf
+ * http://www.ti.com/lit/ds/symlink/adc101s021.pdf
+ * http://www.ti.com/lit/ds/symlink/adc121s021.pdf
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/spi/spi.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/acpi.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/regulator/consumer.h>
+
+struct adc081s {
+ struct spi_device *spi;
+ struct regulator *reg;
+ struct mutex lock;
+
+ /* 8, 10 or 12 */
+ int bits;
+};
+
+static int adc081s_read_raw(struct iio_dev *iio,
+ struct iio_chan_spec const *channel, int *value,
+ int *shift, long mask)
+{
+ struct adc081s *adc = iio_priv(iio);
+ int ret;
+ __be16 buf;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&adc->lock);
+ ret = spi_read(adc->spi, (void *) &buf, 2);
+ mutex_unlock(&adc->lock);
+ if (ret)
+ return ret;
+ *value = (be16_to_cpu(buf) & 0x0FFF) >> (12 - adc->bits);
+ *value = sign_extend32(*value, channel->scan_type.realbits - 1);
+
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ *value = regulator_get_voltage(adc->reg);
+ if (*value < 0)
+ return *value;
+
+ /* convert regulator output voltage to mV */
+ *value /= 1000;
+ *shift = adc->bits;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ default:
+ break;
+ }
+
+ return -EINVAL;
+}
+
+#define ADCxx1S_CHAN(_bits) { \
+ .type = IIO_VOLTAGE, \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = (_bits), \
+ .storagebits = 16, \
+ .shift = 12 - (_bits), \
+ .endianness = IIO_CPU, \
+ }, \
+}
+
+#define DEFINE_ADCxx1S_CHANNELS(_name, _bits) \
+ static const struct iio_chan_spec _name ## _channels[] = { \
+ ADCxx1S_CHAN((_bits)), \
+ IIO_CHAN_SOFT_TIMESTAMP(1), \
+ } \
+
+#define ADC081S_NUM_CHANNELS 2
+
+struct adcxx1s_model {
+ const struct iio_chan_spec *channels;
+ int bits;
+};
+
+#define ADCxx1S_MODEL(_name, _bits) \
+ { \
+ .channels = _name ## _channels, \
+ .bits = (_bits), \
+ }
+
+DEFINE_ADCxx1S_CHANNELS(adc081s, 8);
+DEFINE_ADCxx1S_CHANNELS(adc101s, 10);
+DEFINE_ADCxx1S_CHANNELS(adc121s, 12);
+
+/* Model ids are indexes in _models array */
+enum adcxx1s_model_id {
+ ADC081S = 0,
+ ADC101S = 1,
+ ADC121S = 2,
+};
+
+static struct adcxx1s_model adcxx1s_models[] = {
+ ADCxx1S_MODEL(adc081s, 8),
+ ADCxx1S_MODEL(adc101s, 10),
+ ADCxx1S_MODEL(adc121s, 12),
+};
+
+static const struct iio_info adc081s_info = {
+ .read_raw = adc081s_read_raw,
+};
+
+static int adc081s_probe(struct spi_device *spi)
+{
+ struct iio_dev *iio;
+ struct adc081s *adc;
+ struct adcxx1s_model *model;
+ int err;
+
+ if (ACPI_COMPANION(&spi->dev)) {
+ const struct acpi_device_id *ad_id;
+
+ ad_id = acpi_match_device(spi->dev.driver->acpi_match_table,
+ &spi->dev);
+ if (!ad_id)
+ return -ENODEV;
+ model = &adcxx1s_models[ad_id->driver_data];
+ } else {
+ model = &adcxx1s_models[spi_get_device_id(spi)->driver_data];
+ }
+
+ iio = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
+ if (!iio)
+ return -ENOMEM;
+
+ adc = iio_priv(iio);
+ adc->spi = spi;
+ adc->bits = model->bits;
+ mutex_init(&adc->lock);
+
+ adc->reg = devm_regulator_get(&spi->dev, "vref");
+ if (IS_ERR(adc->reg))
+ return PTR_ERR(adc->reg);
+
+ err = regulator_enable(adc->reg);
+ if (err < 0)
+ return err;
+
+ iio->dev.parent = &spi->dev;
+ iio->dev.of_node = spi->dev.of_node;
+ iio->name = dev_name(&spi->dev);
+ iio->modes = INDIO_DIRECT_MODE;
+ iio->info = &adc081s_info;
+
+ iio->channels = model->channels;
+ iio->num_channels = ADC081S_NUM_CHANNELS;
+
+ err = iio_device_register(iio);
+ if (err < 0)
+ goto err_regulator_disable;
+
+ spi_set_drvdata(spi, iio);
+
+ return 0;
+
+err_regulator_disable:
+ regulator_disable(adc->reg);
+
+ return err;
+}
+
+static int adc081s_remove(struct spi_device *spi)
+{
+ struct iio_dev *iio = spi_get_drvdata(spi);
+ struct adc081s *adc = iio_priv(iio);
+
+ iio_device_unregister(iio);
+ regulator_disable(adc->reg);
+
+ return 0;
+}
+
+static const struct spi_device_id adc081s_id[] = {
+ { "adc081s", ADC081S },
+ { "adc101s", ADC101S },
+ { "adc121s", ADC121S },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, adc081s_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id adc081s_of_match[] = {
+ { .compatible = "ti,adc081s" },
+ { .compatible = "ti,adc101s" },
+ { .compatible = "ti,adc121s" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, adc081s_of_match);
+#endif
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id adc081s_acpi_match[] = {
+ { "ADC081S", ADC081S },
+ { "ADC101S", ADC101S },
+ { "ADC121S", ADC121S },
+ { }
+};
+MODULE_DEVICE_TABLE(acpi, adc081s_acpi_match);
+#endif
+
+static struct spi_driver adc081s_driver = {
+ .driver = {
+ .name = "adc081s",
+ .of_match_table = of_match_ptr(adc081s_of_match),
+ .acpi_match_table = ACPI_PTR(adc081s_acpi_match),
+ },
+ .probe = adc081s_probe,
+ .remove = adc081s_remove,
+ .id_table = adc081s_id,
+};
+module_spi_driver(adc081s_driver);
+
+MODULE_AUTHOR("Milan Stevanovic <milan.o.stevanovic@xxxxxxxxx>");
+MODULE_DESCRIPTION("Texas Instruments ADC081S/ADC101S/ADC121S driver");
+MODULE_LICENSE("GPL v2");
--
2.7.4