* [PATCH] iio: adc: add ADC12130/ADC12132/ADC12138 ADC driver
@ 2016-07-18 15:00 ` Akinobu Mita
0 siblings, 0 replies; 10+ messages in thread
From: Akinobu Mita @ 2016-07-18 15:00 UTC (permalink / raw)
To: linux-iio-u79uwXL29TY76Z2rM5mHXA, devicetree-u79uwXL29TY76Z2rM5mHXA
Cc: Akinobu Mita, Jonathan Cameron, Hartmut Knaack,
Lars-Peter Clausen, Peter Meerwald
This adds Texas Instruments' ADC12130/ADC12132/ADC12138 12-bit plus
sign ADC driver. I have tested with the ADC12138. The ADC12130 and
ADC12132 are not tested but these are similar to ADC12138 except that
the mode programming instruction is a bit different.
Signed-off-by: Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Hartmut Knaack <knaack.h-Mmb7MZpHnFY@public.gmane.org>
Cc: Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>
Cc: Peter Meerwald <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
---
.../devicetree/bindings/iio/adc/ti-adc12138.txt | 32 ++
drivers/iio/adc/Kconfig | 12 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti-adc12138.c | 541 +++++++++++++++++++++
4 files changed, 586 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
create mode 100644 drivers/iio/adc/ti-adc12138.c
diff --git a/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
new file mode 100644
index 0000000..3a11d2a
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
@@ -0,0 +1,32 @@
+* Texas Instruments' ADC12130/ADC12132/ADC12138
+
+Required properties:
+ - compatible: Should be one of
+ * "ti,adc12130"
+ * "ti,adc12132"
+ * "ti,adc12138"
+ - reg: SPI chip select number for the device
+ - interrupts: Should contain interrupt for EOC (end of conversion)
+ - clocks: phandle to conversion clock input
+ - spi-max-frequency: Definision as per
+ Documentation/devicetree/bindings/spi/spi-bus.txt
+ - vref-p-supply: The regulator supply for positive analog voltage reference
+
+Optional properties:
+ - vref-n-supply: The regulator supply for negative analog voltage reference
+ If not specified, this is assumed to be analog ground.
+ - acquisition-time: The number of conversion clock periods for the S/H's
+ acquisition time. Should be one of 6, 10, 18, 34. If not specified,
+ default value of 10 is used.
+
+Example:
+adc@0 {
+ compatible = "ti,adc12138";
+ reg = <0>;
+ interrupts = <28 IRQ_TYPE_EDGE_RISING>;
+ interrupt-parent = <&gpio1>;
+ clocks = <&cclk>;
+ vref-p-supply = <&ldo4_reg>;
+ spi-max-frequency = <5000000>;
+ acquisition-time = <6>;
+};
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index fa0ff29..0783291 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -414,6 +414,18 @@ config TI_ADC0832
This driver can also be built as a module. If so, the module will be
called ti-adc0832.
+config TI_ADC12138
+ tristate "Texas Instruments ADC12130/ADC12132/ADC12138"
+ depends on SPI
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ help
+ If you say yes here you get support for Texas Instruments ADC12130,
+ ADC12132and ADC12138 chips.
+
+ This driver can also be built as a module. If so, the module will be
+ called ti-adc12138.
+
config TI_ADC128S052
tristate "Texas Instruments ADC128S052/ADC122S021/ADC124S021"
depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 599714b..3ae4ae3 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
+obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o
obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
diff --git a/drivers/iio/adc/ti-adc12138.c b/drivers/iio/adc/ti-adc12138.c
new file mode 100644
index 0000000..e7bd986
--- /dev/null
+++ b/drivers/iio/adc/ti-adc12138.c
@@ -0,0 +1,541 @@
+/*
+ * ADC12130/ADC12132/ADC12138 12-bit plus sign ADC driver
+ *
+ * Copyright (c) 2016 Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * Datasheet: http://www.ti.com/lit/ds/symlink/adc12138.pdf
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
+#include <linux/clk.h>
+#include <linux/spi/spi.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/regulator/consumer.h>
+
+#define ADC12138_MODE_AUTO_CAL 0x08
+#define ADC12138_MODE_READ_STATUS 0x0c
+#define ADC12138_MODE_ACQUISITION_TIME_6 0x0e
+#define ADC12138_MODE_ACQUISITION_TIME_10 0x4e
+#define ADC12138_MODE_ACQUISITION_TIME_18 0x8e
+#define ADC12138_MODE_ACQUISITION_TIME_34 0xce
+
+#define ADC12138_STATUS_CAL BIT(6)
+
+enum {
+ adc12130,
+ adc12132,
+ adc12138,
+};
+
+struct adc12138 {
+ struct spi_device *spi;
+ unsigned int id;
+ /* conversion clock */
+ struct clk *cclk;
+ /* positive analog voltage reference */
+ struct regulator *vref_p;
+ /* negative analog voltage reference */
+ struct regulator *vref_n;
+ struct mutex lock;
+ struct completion complete;
+ unsigned int acquisition_time;
+
+ u8 tx_buf[2] ____cacheline_aligned;
+ u8 rx_buf[2];
+};
+
+#define ADC12138_VOLTAGE_CHANNEL(chan) \
+ { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = chan, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
+ | BIT(IIO_CHAN_INFO_OFFSET), \
+ .scan_index = chan, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 13, \
+ .storagebits = 16, \
+ .shift = 3, \
+ .endianness = IIO_BE, \
+ }, \
+ }
+
+#define ADC12138_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si_offset) \
+ { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = (chan1), \
+ .channel2 = (chan2), \
+ .differential = 1, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
+ | BIT(IIO_CHAN_INFO_OFFSET), \
+ .scan_index = (chan1) + (si_offset), \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 13, \
+ .storagebits = 16, \
+ .shift = 3, \
+ .endianness = IIO_BE, \
+ }, \
+ }
+
+static const struct iio_chan_spec adc12132_channels[] = {
+ ADC12138_VOLTAGE_CHANNEL(0),
+ ADC12138_VOLTAGE_CHANNEL(1),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 2),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 2),
+ IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+static const struct iio_chan_spec adc12138_channels[] = {
+ ADC12138_VOLTAGE_CHANNEL(0),
+ ADC12138_VOLTAGE_CHANNEL(1),
+ ADC12138_VOLTAGE_CHANNEL(2),
+ ADC12138_VOLTAGE_CHANNEL(3),
+ ADC12138_VOLTAGE_CHANNEL(4),
+ ADC12138_VOLTAGE_CHANNEL(5),
+ ADC12138_VOLTAGE_CHANNEL(6),
+ ADC12138_VOLTAGE_CHANNEL(7),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(2, 3, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(3, 2, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(4, 5, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(5, 4, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(6, 7, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(7, 6, 8),
+ IIO_CHAN_SOFT_TIMESTAMP(16),
+};
+
+static int adc12138_mode_programming(struct adc12138 *adc, u8 mode,
+ void *rx_buf, int len)
+{
+ struct spi_transfer xfer = {
+ .tx_buf = adc->tx_buf,
+ .rx_buf = adc->rx_buf,
+ .len = len,
+ };
+ int ret;
+
+ /* Skip disused bits for ADC12130 and ADC12132 */
+ if (adc->id != adc12138)
+ mode = (mode & 0xc0) | ((mode & 0x0f) << 2);
+
+ adc->tx_buf[0] = mode;
+
+ ret = spi_sync_transfer(adc->spi, &xfer, 1);
+ if (ret)
+ return ret;
+
+ memcpy(rx_buf, adc->rx_buf, len);
+
+ return 0;
+}
+
+static int adc12138_read_status(struct adc12138 *adc)
+{
+ u8 rx_buf[2];
+ int ret;
+
+ ret = adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
+ rx_buf, 2);
+ if (ret)
+ return ret;
+
+ return (rx_buf[0] << 1) | (rx_buf[1] >> 7);
+}
+
+static int __adc12138_start_conv(struct adc12138 *adc,
+ struct iio_chan_spec const *channel,
+ void *data, int len)
+
+{
+ const u8 ch_to_mux[] = { 0, 4, 1, 5, 2, 6, 3, 7 };
+ u8 mode = (ch_to_mux[channel->channel] << 4) |
+ (channel->differential ? 0 : 0x80);
+
+ return adc12138_mode_programming(adc, mode, data, len);
+}
+
+static int adc12138_start_conv(struct adc12138 *adc,
+ struct iio_chan_spec const *channel)
+{
+ u8 trash;
+
+ return __adc12138_start_conv(adc, channel, &trash, 1);
+}
+
+static int adc12138_start_and_read_conv(struct adc12138 *adc,
+ struct iio_chan_spec const *channel,
+ __be16 *data)
+{
+ return __adc12138_start_conv(adc, channel, data, 2);
+}
+
+static int adc12138_read_conv_data(struct adc12138 *adc, __be16 *value)
+{
+ /* Issue a read status instruction and read previous conversion data */
+ return adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
+ value, sizeof(*value));
+}
+
+static int adc12138_wait_eoc(struct adc12138 *adc, unsigned long timeout)
+{
+ if (!wait_for_completion_timeout(&adc->complete, timeout))
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static int adc12138_adc_conversion(struct adc12138 *adc,
+ struct iio_chan_spec const *channel,
+ __be16 *value)
+{
+ int ret;
+
+ reinit_completion(&adc->complete);
+
+ ret = adc12138_start_conv(adc, channel);
+ if (ret)
+ return ret;
+
+ ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
+ if (ret)
+ return ret;
+
+ return adc12138_read_conv_data(adc, value);
+}
+
+static int adc12138_read_raw(struct iio_dev *iio,
+ struct iio_chan_spec const *channel, int *value,
+ int *shift, long mask)
+{
+ struct adc12138 *adc = iio_priv(iio);
+ int ret;
+ __be16 data;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&adc->lock);
+ ret = adc12138_adc_conversion(adc, channel, &data);
+ mutex_unlock(&adc->lock);
+ if (ret)
+ return ret;
+
+ *value = sign_extend32(be16_to_cpu(data) >> 3, 12);
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ ret = regulator_get_voltage(adc->vref_p);
+ if (ret < 0)
+ return ret;
+ *value = ret;
+
+ if (!IS_ERR(adc->vref_n)) {
+ ret = regulator_get_voltage(adc->vref_n);
+ if (ret < 0)
+ return ret;
+ *value -= ret;
+ }
+
+ /* convert regulator output voltage to mV */
+ *value /= 1000;
+ *shift = channel->scan_type.realbits - 1;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+ case IIO_CHAN_INFO_OFFSET:
+ if (!IS_ERR(adc->vref_n)) {
+ *value = regulator_get_voltage(adc->vref_n);
+ if (*value < 0)
+ return *value;
+ } else {
+ *value = 0;
+ }
+
+ /* convert regulator output voltage to mV */
+ *value /= 1000;
+
+ return IIO_VAL_INT;
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info adc12138_info = {
+ .read_raw = adc12138_read_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static int adc12138_init(struct adc12138 *adc)
+{
+ int ret;
+ int status;
+ u8 mode;
+ u8 trash;
+
+ reinit_completion(&adc->complete);
+
+ ret = adc12138_mode_programming(adc, ADC12138_MODE_AUTO_CAL, &trash, 1);
+ if (ret)
+ return ret;
+
+ /* data output at this time has no significance */
+ status = adc12138_read_status(adc);
+ if (status < 0)
+ return status;
+
+ adc12138_wait_eoc(adc, msecs_to_jiffies(100));
+
+ status = adc12138_read_status(adc);
+ if (status & ADC12138_STATUS_CAL) {
+ dev_warn(&adc->spi->dev,
+ "Auto Cal sequence is still in progress: %#x\n",
+ status);
+ return -EIO;
+ }
+
+ switch (adc->acquisition_time) {
+ case 6:
+ mode = ADC12138_MODE_ACQUISITION_TIME_6;
+ break;
+ case 10:
+ mode = ADC12138_MODE_ACQUISITION_TIME_10;
+ break;
+ case 18:
+ mode = ADC12138_MODE_ACQUISITION_TIME_18;
+ break;
+ case 34:
+ mode = ADC12138_MODE_ACQUISITION_TIME_34;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return adc12138_mode_programming(adc, mode, &trash, 1);
+}
+
+static irqreturn_t adc12138_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct adc12138 *adc = iio_priv(indio_dev);
+ __be16 data[20] = { };
+ __be16 trash;
+ int ret;
+ int scan_index;
+ int i = 0;
+
+ mutex_lock(&adc->lock);
+
+ for_each_set_bit(scan_index, indio_dev->active_scan_mask,
+ indio_dev->masklength) {
+ const struct iio_chan_spec *scan_chan =
+ &indio_dev->channels[scan_index];
+
+ reinit_completion(&adc->complete);
+
+ ret = adc12138_start_and_read_conv(adc, scan_chan,
+ i ? &data[i - 1] : &trash);
+ if (ret) {
+ dev_warn(&adc->spi->dev,
+ "failed to start conversion\n");
+ goto out;
+ }
+
+ ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
+ if (ret) {
+ dev_warn(&adc->spi->dev, "wait eoc timeout\n");
+ goto out;
+ }
+
+ i++;
+ }
+
+ if (i) {
+ ret = adc12138_read_conv_data(adc, &data[i - 1]);
+ if (ret) {
+ dev_warn(&adc->spi->dev,
+ "failed to get conversion data\n");
+ goto out;
+ }
+ }
+
+ iio_push_to_buffers_with_timestamp(indio_dev, data, iio_get_time_ns());
+out:
+ mutex_unlock(&adc->lock);
+
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t adc12138_eoc_handler(int irq, void *p)
+{
+ struct iio_dev *indio_dev = p;
+ struct adc12138 *adc = iio_priv(indio_dev);
+
+ complete(&adc->complete);
+
+ return IRQ_HANDLED;
+}
+
+static int adc12138_probe(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev;
+ struct adc12138 *adc;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ adc = iio_priv(indio_dev);
+ adc->spi = spi;
+ adc->id = spi_get_device_id(spi)->driver_data;
+ mutex_init(&adc->lock);
+ init_completion(&adc->complete);
+
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->info = &adc12138_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ switch (adc->id) {
+ case adc12130:
+ case adc12132:
+ indio_dev->channels = adc12132_channels;
+ indio_dev->num_channels = ARRAY_SIZE(adc12132_channels);
+ break;
+ case adc12138:
+ indio_dev->channels = adc12138_channels;
+ indio_dev->num_channels = ARRAY_SIZE(adc12138_channels);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = of_property_read_u32(spi->dev.of_node, "acquisition-time",
+ &adc->acquisition_time);
+ if (ret)
+ adc->acquisition_time = 10;
+
+ adc->cclk = devm_clk_get(&spi->dev, NULL);
+ if (IS_ERR(adc->cclk))
+ return PTR_ERR(adc->cclk);
+
+ adc->vref_p = devm_regulator_get(&spi->dev, "vref-p");
+ if (IS_ERR(adc->vref_p))
+ return PTR_ERR(adc->vref_p);
+
+ adc->vref_n = devm_regulator_get_optional(&spi->dev, "vref-n");
+
+ ret = devm_request_irq(&spi->dev, spi->irq, adc12138_eoc_handler,
+ IRQF_TRIGGER_RISING, indio_dev->name, indio_dev);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(adc->cclk);
+ if (ret)
+ return ret;
+
+ ret = regulator_enable(adc->vref_p);
+ if (ret)
+ goto error1;
+
+ if (!IS_ERR(adc->vref_n)) {
+ ret = regulator_enable(adc->vref_n);
+ if (ret)
+ goto error2;
+ }
+
+ ret = adc12138_init(adc);
+ if (ret)
+ goto error3;
+
+ spi_set_drvdata(spi, indio_dev);
+
+ ret = iio_triggered_buffer_setup(indio_dev, NULL,
+ adc12138_trigger_handler, NULL);
+ if (ret)
+ goto error3;
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error4;
+
+ return 0;
+error4:
+ iio_triggered_buffer_cleanup(indio_dev);
+error3:
+ if (!IS_ERR(adc->vref_n))
+ regulator_disable(adc->vref_n);
+error2:
+ regulator_disable(adc->vref_p);
+error1:
+ clk_disable_unprepare(adc->cclk);
+
+ return ret;
+}
+
+static int adc12138_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct adc12138 *adc = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
+ if (!IS_ERR(adc->vref_n))
+ regulator_disable(adc->vref_n);
+ regulator_disable(adc->vref_p);
+ clk_disable_unprepare(adc->cclk);
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+
+static const struct of_device_id adc12138_dt_ids[] = {
+ { .compatible = "ti,adc12130", },
+ { .compatible = "ti,adc12132", },
+ { .compatible = "ti,adc12138", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, adc12138_dt_ids);
+
+#endif
+
+static const struct spi_device_id adc12138_id[] = {
+ { "adc12130", adc12130 },
+ { "adc12132", adc12132 },
+ { "adc12138", adc12138 },
+ {}
+};
+MODULE_DEVICE_TABLE(spi, adc12138_id);
+
+static struct spi_driver adc12138_driver = {
+ .driver = {
+ .name = "adc12138",
+ .of_match_table = of_match_ptr(adc12138_dt_ids),
+ },
+ .probe = adc12138_probe,
+ .remove = adc12138_remove,
+ .id_table = adc12138_id,
+};
+module_spi_driver(adc12138_driver);
+
+MODULE_AUTHOR("Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
+MODULE_DESCRIPTION("ADC12130/ADC12132/ADC12138 driver");
+MODULE_LICENSE("GPL v2");
--
2.7.4
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH] iio: adc: add ADC12130/ADC12132/ADC12138 ADC driver
@ 2016-07-18 15:00 ` Akinobu Mita
0 siblings, 0 replies; 10+ messages in thread
From: Akinobu Mita @ 2016-07-18 15:00 UTC (permalink / raw)
To: linux-iio, devicetree
Cc: Akinobu Mita, Jonathan Cameron, Hartmut Knaack,
Lars-Peter Clausen, Peter Meerwald
This adds Texas Instruments' ADC12130/ADC12132/ADC12138 12-bit plus
sign ADC driver. I have tested with the ADC12138. The ADC12130 and
ADC12132 are not tested but these are similar to ADC12138 except that
the mode programming instruction is a bit different.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald <pmeerw@pmeerw.net>
---
.../devicetree/bindings/iio/adc/ti-adc12138.txt | 32 ++
drivers/iio/adc/Kconfig | 12 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti-adc12138.c | 541 +++++++++++++++++++++
4 files changed, 586 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
create mode 100644 drivers/iio/adc/ti-adc12138.c
diff --git a/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
new file mode 100644
index 0000000..3a11d2a
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
@@ -0,0 +1,32 @@
+* Texas Instruments' ADC12130/ADC12132/ADC12138
+
+Required properties:
+ - compatible: Should be one of
+ * "ti,adc12130"
+ * "ti,adc12132"
+ * "ti,adc12138"
+ - reg: SPI chip select number for the device
+ - interrupts: Should contain interrupt for EOC (end of conversion)
+ - clocks: phandle to conversion clock input
+ - spi-max-frequency: Definision as per
+ Documentation/devicetree/bindings/spi/spi-bus.txt
+ - vref-p-supply: The regulator supply for positive analog voltage reference
+
+Optional properties:
+ - vref-n-supply: The regulator supply for negative analog voltage reference
+ If not specified, this is assumed to be analog ground.
+ - acquisition-time: The number of conversion clock periods for the S/H's
+ acquisition time. Should be one of 6, 10, 18, 34. If not specified,
+ default value of 10 is used.
+
+Example:
+adc@0 {
+ compatible = "ti,adc12138";
+ reg = <0>;
+ interrupts = <28 IRQ_TYPE_EDGE_RISING>;
+ interrupt-parent = <&gpio1>;
+ clocks = <&cclk>;
+ vref-p-supply = <&ldo4_reg>;
+ spi-max-frequency = <5000000>;
+ acquisition-time = <6>;
+};
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index fa0ff29..0783291 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -414,6 +414,18 @@ config TI_ADC0832
This driver can also be built as a module. If so, the module will be
called ti-adc0832.
+config TI_ADC12138
+ tristate "Texas Instruments ADC12130/ADC12132/ADC12138"
+ depends on SPI
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ help
+ If you say yes here you get support for Texas Instruments ADC12130,
+ ADC12132and ADC12138 chips.
+
+ This driver can also be built as a module. If so, the module will be
+ called ti-adc12138.
+
config TI_ADC128S052
tristate "Texas Instruments ADC128S052/ADC122S021/ADC124S021"
depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 599714b..3ae4ae3 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
+obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o
obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
diff --git a/drivers/iio/adc/ti-adc12138.c b/drivers/iio/adc/ti-adc12138.c
new file mode 100644
index 0000000..e7bd986
--- /dev/null
+++ b/drivers/iio/adc/ti-adc12138.c
@@ -0,0 +1,541 @@
+/*
+ * ADC12130/ADC12132/ADC12138 12-bit plus sign ADC driver
+ *
+ * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * Datasheet: http://www.ti.com/lit/ds/symlink/adc12138.pdf
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
+#include <linux/clk.h>
+#include <linux/spi/spi.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/regulator/consumer.h>
+
+#define ADC12138_MODE_AUTO_CAL 0x08
+#define ADC12138_MODE_READ_STATUS 0x0c
+#define ADC12138_MODE_ACQUISITION_TIME_6 0x0e
+#define ADC12138_MODE_ACQUISITION_TIME_10 0x4e
+#define ADC12138_MODE_ACQUISITION_TIME_18 0x8e
+#define ADC12138_MODE_ACQUISITION_TIME_34 0xce
+
+#define ADC12138_STATUS_CAL BIT(6)
+
+enum {
+ adc12130,
+ adc12132,
+ adc12138,
+};
+
+struct adc12138 {
+ struct spi_device *spi;
+ unsigned int id;
+ /* conversion clock */
+ struct clk *cclk;
+ /* positive analog voltage reference */
+ struct regulator *vref_p;
+ /* negative analog voltage reference */
+ struct regulator *vref_n;
+ struct mutex lock;
+ struct completion complete;
+ unsigned int acquisition_time;
+
+ u8 tx_buf[2] ____cacheline_aligned;
+ u8 rx_buf[2];
+};
+
+#define ADC12138_VOLTAGE_CHANNEL(chan) \
+ { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = chan, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
+ | BIT(IIO_CHAN_INFO_OFFSET), \
+ .scan_index = chan, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 13, \
+ .storagebits = 16, \
+ .shift = 3, \
+ .endianness = IIO_BE, \
+ }, \
+ }
+
+#define ADC12138_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si_offset) \
+ { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = (chan1), \
+ .channel2 = (chan2), \
+ .differential = 1, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
+ | BIT(IIO_CHAN_INFO_OFFSET), \
+ .scan_index = (chan1) + (si_offset), \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 13, \
+ .storagebits = 16, \
+ .shift = 3, \
+ .endianness = IIO_BE, \
+ }, \
+ }
+
+static const struct iio_chan_spec adc12132_channels[] = {
+ ADC12138_VOLTAGE_CHANNEL(0),
+ ADC12138_VOLTAGE_CHANNEL(1),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 2),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 2),
+ IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+static const struct iio_chan_spec adc12138_channels[] = {
+ ADC12138_VOLTAGE_CHANNEL(0),
+ ADC12138_VOLTAGE_CHANNEL(1),
+ ADC12138_VOLTAGE_CHANNEL(2),
+ ADC12138_VOLTAGE_CHANNEL(3),
+ ADC12138_VOLTAGE_CHANNEL(4),
+ ADC12138_VOLTAGE_CHANNEL(5),
+ ADC12138_VOLTAGE_CHANNEL(6),
+ ADC12138_VOLTAGE_CHANNEL(7),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(2, 3, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(3, 2, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(4, 5, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(5, 4, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(6, 7, 8),
+ ADC12138_VOLTAGE_CHANNEL_DIFF(7, 6, 8),
+ IIO_CHAN_SOFT_TIMESTAMP(16),
+};
+
+static int adc12138_mode_programming(struct adc12138 *adc, u8 mode,
+ void *rx_buf, int len)
+{
+ struct spi_transfer xfer = {
+ .tx_buf = adc->tx_buf,
+ .rx_buf = adc->rx_buf,
+ .len = len,
+ };
+ int ret;
+
+ /* Skip disused bits for ADC12130 and ADC12132 */
+ if (adc->id != adc12138)
+ mode = (mode & 0xc0) | ((mode & 0x0f) << 2);
+
+ adc->tx_buf[0] = mode;
+
+ ret = spi_sync_transfer(adc->spi, &xfer, 1);
+ if (ret)
+ return ret;
+
+ memcpy(rx_buf, adc->rx_buf, len);
+
+ return 0;
+}
+
+static int adc12138_read_status(struct adc12138 *adc)
+{
+ u8 rx_buf[2];
+ int ret;
+
+ ret = adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
+ rx_buf, 2);
+ if (ret)
+ return ret;
+
+ return (rx_buf[0] << 1) | (rx_buf[1] >> 7);
+}
+
+static int __adc12138_start_conv(struct adc12138 *adc,
+ struct iio_chan_spec const *channel,
+ void *data, int len)
+
+{
+ const u8 ch_to_mux[] = { 0, 4, 1, 5, 2, 6, 3, 7 };
+ u8 mode = (ch_to_mux[channel->channel] << 4) |
+ (channel->differential ? 0 : 0x80);
+
+ return adc12138_mode_programming(adc, mode, data, len);
+}
+
+static int adc12138_start_conv(struct adc12138 *adc,
+ struct iio_chan_spec const *channel)
+{
+ u8 trash;
+
+ return __adc12138_start_conv(adc, channel, &trash, 1);
+}
+
+static int adc12138_start_and_read_conv(struct adc12138 *adc,
+ struct iio_chan_spec const *channel,
+ __be16 *data)
+{
+ return __adc12138_start_conv(adc, channel, data, 2);
+}
+
+static int adc12138_read_conv_data(struct adc12138 *adc, __be16 *value)
+{
+ /* Issue a read status instruction and read previous conversion data */
+ return adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
+ value, sizeof(*value));
+}
+
+static int adc12138_wait_eoc(struct adc12138 *adc, unsigned long timeout)
+{
+ if (!wait_for_completion_timeout(&adc->complete, timeout))
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static int adc12138_adc_conversion(struct adc12138 *adc,
+ struct iio_chan_spec const *channel,
+ __be16 *value)
+{
+ int ret;
+
+ reinit_completion(&adc->complete);
+
+ ret = adc12138_start_conv(adc, channel);
+ if (ret)
+ return ret;
+
+ ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
+ if (ret)
+ return ret;
+
+ return adc12138_read_conv_data(adc, value);
+}
+
+static int adc12138_read_raw(struct iio_dev *iio,
+ struct iio_chan_spec const *channel, int *value,
+ int *shift, long mask)
+{
+ struct adc12138 *adc = iio_priv(iio);
+ int ret;
+ __be16 data;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&adc->lock);
+ ret = adc12138_adc_conversion(adc, channel, &data);
+ mutex_unlock(&adc->lock);
+ if (ret)
+ return ret;
+
+ *value = sign_extend32(be16_to_cpu(data) >> 3, 12);
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ ret = regulator_get_voltage(adc->vref_p);
+ if (ret < 0)
+ return ret;
+ *value = ret;
+
+ if (!IS_ERR(adc->vref_n)) {
+ ret = regulator_get_voltage(adc->vref_n);
+ if (ret < 0)
+ return ret;
+ *value -= ret;
+ }
+
+ /* convert regulator output voltage to mV */
+ *value /= 1000;
+ *shift = channel->scan_type.realbits - 1;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+ case IIO_CHAN_INFO_OFFSET:
+ if (!IS_ERR(adc->vref_n)) {
+ *value = regulator_get_voltage(adc->vref_n);
+ if (*value < 0)
+ return *value;
+ } else {
+ *value = 0;
+ }
+
+ /* convert regulator output voltage to mV */
+ *value /= 1000;
+
+ return IIO_VAL_INT;
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info adc12138_info = {
+ .read_raw = adc12138_read_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static int adc12138_init(struct adc12138 *adc)
+{
+ int ret;
+ int status;
+ u8 mode;
+ u8 trash;
+
+ reinit_completion(&adc->complete);
+
+ ret = adc12138_mode_programming(adc, ADC12138_MODE_AUTO_CAL, &trash, 1);
+ if (ret)
+ return ret;
+
+ /* data output at this time has no significance */
+ status = adc12138_read_status(adc);
+ if (status < 0)
+ return status;
+
+ adc12138_wait_eoc(adc, msecs_to_jiffies(100));
+
+ status = adc12138_read_status(adc);
+ if (status & ADC12138_STATUS_CAL) {
+ dev_warn(&adc->spi->dev,
+ "Auto Cal sequence is still in progress: %#x\n",
+ status);
+ return -EIO;
+ }
+
+ switch (adc->acquisition_time) {
+ case 6:
+ mode = ADC12138_MODE_ACQUISITION_TIME_6;
+ break;
+ case 10:
+ mode = ADC12138_MODE_ACQUISITION_TIME_10;
+ break;
+ case 18:
+ mode = ADC12138_MODE_ACQUISITION_TIME_18;
+ break;
+ case 34:
+ mode = ADC12138_MODE_ACQUISITION_TIME_34;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return adc12138_mode_programming(adc, mode, &trash, 1);
+}
+
+static irqreturn_t adc12138_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct adc12138 *adc = iio_priv(indio_dev);
+ __be16 data[20] = { };
+ __be16 trash;
+ int ret;
+ int scan_index;
+ int i = 0;
+
+ mutex_lock(&adc->lock);
+
+ for_each_set_bit(scan_index, indio_dev->active_scan_mask,
+ indio_dev->masklength) {
+ const struct iio_chan_spec *scan_chan =
+ &indio_dev->channels[scan_index];
+
+ reinit_completion(&adc->complete);
+
+ ret = adc12138_start_and_read_conv(adc, scan_chan,
+ i ? &data[i - 1] : &trash);
+ if (ret) {
+ dev_warn(&adc->spi->dev,
+ "failed to start conversion\n");
+ goto out;
+ }
+
+ ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
+ if (ret) {
+ dev_warn(&adc->spi->dev, "wait eoc timeout\n");
+ goto out;
+ }
+
+ i++;
+ }
+
+ if (i) {
+ ret = adc12138_read_conv_data(adc, &data[i - 1]);
+ if (ret) {
+ dev_warn(&adc->spi->dev,
+ "failed to get conversion data\n");
+ goto out;
+ }
+ }
+
+ iio_push_to_buffers_with_timestamp(indio_dev, data, iio_get_time_ns());
+out:
+ mutex_unlock(&adc->lock);
+
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t adc12138_eoc_handler(int irq, void *p)
+{
+ struct iio_dev *indio_dev = p;
+ struct adc12138 *adc = iio_priv(indio_dev);
+
+ complete(&adc->complete);
+
+ return IRQ_HANDLED;
+}
+
+static int adc12138_probe(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev;
+ struct adc12138 *adc;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ adc = iio_priv(indio_dev);
+ adc->spi = spi;
+ adc->id = spi_get_device_id(spi)->driver_data;
+ mutex_init(&adc->lock);
+ init_completion(&adc->complete);
+
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->info = &adc12138_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ switch (adc->id) {
+ case adc12130:
+ case adc12132:
+ indio_dev->channels = adc12132_channels;
+ indio_dev->num_channels = ARRAY_SIZE(adc12132_channels);
+ break;
+ case adc12138:
+ indio_dev->channels = adc12138_channels;
+ indio_dev->num_channels = ARRAY_SIZE(adc12138_channels);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = of_property_read_u32(spi->dev.of_node, "acquisition-time",
+ &adc->acquisition_time);
+ if (ret)
+ adc->acquisition_time = 10;
+
+ adc->cclk = devm_clk_get(&spi->dev, NULL);
+ if (IS_ERR(adc->cclk))
+ return PTR_ERR(adc->cclk);
+
+ adc->vref_p = devm_regulator_get(&spi->dev, "vref-p");
+ if (IS_ERR(adc->vref_p))
+ return PTR_ERR(adc->vref_p);
+
+ adc->vref_n = devm_regulator_get_optional(&spi->dev, "vref-n");
+
+ ret = devm_request_irq(&spi->dev, spi->irq, adc12138_eoc_handler,
+ IRQF_TRIGGER_RISING, indio_dev->name, indio_dev);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(adc->cclk);
+ if (ret)
+ return ret;
+
+ ret = regulator_enable(adc->vref_p);
+ if (ret)
+ goto error1;
+
+ if (!IS_ERR(adc->vref_n)) {
+ ret = regulator_enable(adc->vref_n);
+ if (ret)
+ goto error2;
+ }
+
+ ret = adc12138_init(adc);
+ if (ret)
+ goto error3;
+
+ spi_set_drvdata(spi, indio_dev);
+
+ ret = iio_triggered_buffer_setup(indio_dev, NULL,
+ adc12138_trigger_handler, NULL);
+ if (ret)
+ goto error3;
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error4;
+
+ return 0;
+error4:
+ iio_triggered_buffer_cleanup(indio_dev);
+error3:
+ if (!IS_ERR(adc->vref_n))
+ regulator_disable(adc->vref_n);
+error2:
+ regulator_disable(adc->vref_p);
+error1:
+ clk_disable_unprepare(adc->cclk);
+
+ return ret;
+}
+
+static int adc12138_remove(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev = spi_get_drvdata(spi);
+ struct adc12138 *adc = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
+ if (!IS_ERR(adc->vref_n))
+ regulator_disable(adc->vref_n);
+ regulator_disable(adc->vref_p);
+ clk_disable_unprepare(adc->cclk);
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+
+static const struct of_device_id adc12138_dt_ids[] = {
+ { .compatible = "ti,adc12130", },
+ { .compatible = "ti,adc12132", },
+ { .compatible = "ti,adc12138", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, adc12138_dt_ids);
+
+#endif
+
+static const struct spi_device_id adc12138_id[] = {
+ { "adc12130", adc12130 },
+ { "adc12132", adc12132 },
+ { "adc12138", adc12138 },
+ {}
+};
+MODULE_DEVICE_TABLE(spi, adc12138_id);
+
+static struct spi_driver adc12138_driver = {
+ .driver = {
+ .name = "adc12138",
+ .of_match_table = of_match_ptr(adc12138_dt_ids),
+ },
+ .probe = adc12138_probe,
+ .remove = adc12138_remove,
+ .id_table = adc12138_id,
+};
+module_spi_driver(adc12138_driver);
+
+MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
+MODULE_DESCRIPTION("ADC12130/ADC12132/ADC12138 driver");
+MODULE_LICENSE("GPL v2");
--
2.7.4
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH] iio: adc: add ADC12130/ADC12132/ADC12138 ADC driver
2016-07-18 15:00 ` Akinobu Mita
@ 2016-07-18 22:02 ` Peter Meerwald-Stadler
-1 siblings, 0 replies; 10+ messages in thread
From: Peter Meerwald-Stadler @ 2016-07-18 22:02 UTC (permalink / raw)
To: Akinobu Mita
Cc: linux-iio-u79uwXL29TY76Z2rM5mHXA,
devicetree-u79uwXL29TY76Z2rM5mHXA, Jonathan Cameron,
Hartmut Knaack, Lars-Peter Clausen
[-- Attachment #1: Type: TEXT/PLAIN, Size: 18479 bytes --]
> This adds Texas Instruments' ADC12130/ADC12132/ADC12138 12-bit plus
> sign ADC driver. I have tested with the ADC12138. The ADC12130 and
> ADC12132 are not tested but these are similar to ADC12138 except that
> the mode programming instruction is a bit different.
minor comments below
> Signed-off-by: Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Cc: Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Cc: Hartmut Knaack <knaack.h-Mmb7MZpHnFY@public.gmane.org>
> Cc: Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>
> Cc: Peter Meerwald <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
> ---
> .../devicetree/bindings/iio/adc/ti-adc12138.txt | 32 ++
> drivers/iio/adc/Kconfig | 12 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/ti-adc12138.c | 541 +++++++++++++++++++++
> 4 files changed, 586 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
> create mode 100644 drivers/iio/adc/ti-adc12138.c
>
> diff --git a/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
> new file mode 100644
> index 0000000..3a11d2a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
> @@ -0,0 +1,32 @@
> +* Texas Instruments' ADC12130/ADC12132/ADC12138
> +
> +Required properties:
> + - compatible: Should be one of
> + * "ti,adc12130"
> + * "ti,adc12132"
> + * "ti,adc12138"
> + - reg: SPI chip select number for the device
> + - interrupts: Should contain interrupt for EOC (end of conversion)
> + - clocks: phandle to conversion clock input
> + - spi-max-frequency: Definision as per
> + Documentation/devicetree/bindings/spi/spi-bus.txt
> + - vref-p-supply: The regulator supply for positive analog voltage reference
> +
> +Optional properties:
> + - vref-n-supply: The regulator supply for negative analog voltage reference
> + If not specified, this is assumed to be analog ground.
> + - acquisition-time: The number of conversion clock periods for the S/H's
> + acquisition time. Should be one of 6, 10, 18, 34. If not specified,
> + default value of 10 is used.
> +
> +Example:
> +adc@0 {
> + compatible = "ti,adc12138";
> + reg = <0>;
> + interrupts = <28 IRQ_TYPE_EDGE_RISING>;
> + interrupt-parent = <&gpio1>;
> + clocks = <&cclk>;
> + vref-p-supply = <&ldo4_reg>;
> + spi-max-frequency = <5000000>;
> + acquisition-time = <6>;
> +};
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index fa0ff29..0783291 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -414,6 +414,18 @@ config TI_ADC0832
> This driver can also be built as a module. If so, the module will be
> called ti-adc0832.
>
> +config TI_ADC12138
> + tristate "Texas Instruments ADC12130/ADC12132/ADC12138"
> + depends on SPI
> + select IIO_BUFFER
> + select IIO_TRIGGERED_BUFFER
> + help
> + If you say yes here you get support for Texas Instruments ADC12130,
> + ADC12132and ADC12138 chips.
space before 'and' missing
> +
> + This driver can also be built as a module. If so, the module will be
> + called ti-adc12138.
> +
> config TI_ADC128S052
> tristate "Texas Instruments ADC128S052/ADC122S021/ADC124S021"
> depends on SPI
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 599714b..3ae4ae3 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -40,6 +40,7 @@ obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
> obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
> obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
> +obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o
> obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
> obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
> obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
> diff --git a/drivers/iio/adc/ti-adc12138.c b/drivers/iio/adc/ti-adc12138.c
> new file mode 100644
> index 0000000..e7bd986
> --- /dev/null
> +++ b/drivers/iio/adc/ti-adc12138.c
> @@ -0,0 +1,541 @@
> +/*
> + * ADC12130/ADC12132/ADC12138 12-bit plus sign ADC driver
> + *
> + * Copyright (c) 2016 Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> + *
> + * This file is subject to the terms and conditions of version 2 of
> + * the GNU General Public License. See the file COPYING in the main
> + * directory of this archive for more details.
> + *
> + * Datasheet: http://www.ti.com/lit/ds/symlink/adc12138.pdf
> + */
> +
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/completion.h>
> +#include <linux/clk.h>
> +#include <linux/spi/spi.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/regulator/consumer.h>
> +
> +#define ADC12138_MODE_AUTO_CAL 0x08
> +#define ADC12138_MODE_READ_STATUS 0x0c
> +#define ADC12138_MODE_ACQUISITION_TIME_6 0x0e
> +#define ADC12138_MODE_ACQUISITION_TIME_10 0x4e
> +#define ADC12138_MODE_ACQUISITION_TIME_18 0x8e
> +#define ADC12138_MODE_ACQUISITION_TIME_34 0xce
> +
> +#define ADC12138_STATUS_CAL BIT(6)
> +
> +enum {
> + adc12130,
> + adc12132,
> + adc12138,
> +};
> +
> +struct adc12138 {
> + struct spi_device *spi;
> + unsigned int id;
> + /* conversion clock */
> + struct clk *cclk;
> + /* positive analog voltage reference */
> + struct regulator *vref_p;
> + /* negative analog voltage reference */
> + struct regulator *vref_n;
> + struct mutex lock;
> + struct completion complete;
> + unsigned int acquisition_time;
unit? ms? µs?
> +
> + u8 tx_buf[2] ____cacheline_aligned;
> + u8 rx_buf[2];
> +};
> +
> +#define ADC12138_VOLTAGE_CHANNEL(chan) \
> + { \
> + .type = IIO_VOLTAGE, \
> + .indexed = 1, \
> + .channel = chan, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
> + | BIT(IIO_CHAN_INFO_OFFSET), \
> + .scan_index = chan, \
> + .scan_type = { \
> + .sign = 's', \
> + .realbits = 13, \
> + .storagebits = 16, \
> + .shift = 3, \
> + .endianness = IIO_BE, \
> + }, \
> + }
> +
> +#define ADC12138_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si_offset) \
> + { \
> + .type = IIO_VOLTAGE, \
> + .indexed = 1, \
> + .channel = (chan1), \
> + .channel2 = (chan2), \
> + .differential = 1, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
> + | BIT(IIO_CHAN_INFO_OFFSET), \
> + .scan_index = (chan1) + (si_offset), \
> + .scan_type = { \
> + .sign = 's', \
> + .realbits = 13, \
> + .storagebits = 16, \
> + .shift = 3, \
> + .endianness = IIO_BE, \
> + }, \
> + }
> +
> +static const struct iio_chan_spec adc12132_channels[] = {
> + ADC12138_VOLTAGE_CHANNEL(0),
> + ADC12138_VOLTAGE_CHANNEL(1),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 2),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 2),
> + IIO_CHAN_SOFT_TIMESTAMP(4),
> +};
> +
> +static const struct iio_chan_spec adc12138_channels[] = {
> + ADC12138_VOLTAGE_CHANNEL(0),
> + ADC12138_VOLTAGE_CHANNEL(1),
> + ADC12138_VOLTAGE_CHANNEL(2),
> + ADC12138_VOLTAGE_CHANNEL(3),
> + ADC12138_VOLTAGE_CHANNEL(4),
> + ADC12138_VOLTAGE_CHANNEL(5),
> + ADC12138_VOLTAGE_CHANNEL(6),
> + ADC12138_VOLTAGE_CHANNEL(7),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(2, 3, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(3, 2, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(4, 5, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(5, 4, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(6, 7, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(7, 6, 8),
> + IIO_CHAN_SOFT_TIMESTAMP(16),
> +};
> +
> +static int adc12138_mode_programming(struct adc12138 *adc, u8 mode,
> + void *rx_buf, int len)
> +{
> + struct spi_transfer xfer = {
> + .tx_buf = adc->tx_buf,
> + .rx_buf = adc->rx_buf,
> + .len = len,
> + };
> + int ret;
> +
> + /* Skip disused bits for ADC12130 and ADC12132 */
probably 'unused' instead of 'disused'
> + if (adc->id != adc12138)
> + mode = (mode & 0xc0) | ((mode & 0x0f) << 2);
> +
> + adc->tx_buf[0] = mode;
> +
> + ret = spi_sync_transfer(adc->spi, &xfer, 1);
> + if (ret)
> + return ret;
> +
> + memcpy(rx_buf, adc->rx_buf, len);
> +
> + return 0;
> +}
> +
> +static int adc12138_read_status(struct adc12138 *adc)
> +{
> + u8 rx_buf[2];
> + int ret;
> +
> + ret = adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
> + rx_buf, 2);
> + if (ret)
> + return ret;
> +
> + return (rx_buf[0] << 1) | (rx_buf[1] >> 7);
> +}
> +
> +static int __adc12138_start_conv(struct adc12138 *adc,
> + struct iio_chan_spec const *channel,
> + void *data, int len)
> +
> +{
> + const u8 ch_to_mux[] = { 0, 4, 1, 5, 2, 6, 3, 7 };
> + u8 mode = (ch_to_mux[channel->channel] << 4) |
> + (channel->differential ? 0 : 0x80);
> +
> + return adc12138_mode_programming(adc, mode, data, len);
> +}
> +
> +static int adc12138_start_conv(struct adc12138 *adc,
> + struct iio_chan_spec const *channel)
> +{
> + u8 trash;
> +
> + return __adc12138_start_conv(adc, channel, &trash, 1);
> +}
> +
> +static int adc12138_start_and_read_conv(struct adc12138 *adc,
> + struct iio_chan_spec const *channel,
> + __be16 *data)
> +{
> + return __adc12138_start_conv(adc, channel, data, 2);
> +}
> +
> +static int adc12138_read_conv_data(struct adc12138 *adc, __be16 *value)
> +{
> + /* Issue a read status instruction and read previous conversion data */
> + return adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
> + value, sizeof(*value));
> +}
> +
> +static int adc12138_wait_eoc(struct adc12138 *adc, unsigned long timeout)
> +{
> + if (!wait_for_completion_timeout(&adc->complete, timeout))
> + return -ETIMEDOUT;
> +
> + return 0;
> +}
> +
> +static int adc12138_adc_conversion(struct adc12138 *adc,
> + struct iio_chan_spec const *channel,
> + __be16 *value)
> +{
> + int ret;
> +
> + reinit_completion(&adc->complete);
> +
> + ret = adc12138_start_conv(adc, channel);
> + if (ret)
> + return ret;
> +
> + ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
> + if (ret)
> + return ret;
> +
> + return adc12138_read_conv_data(adc, value);
> +}
> +
> +static int adc12138_read_raw(struct iio_dev *iio,
> + struct iio_chan_spec const *channel, int *value,
> + int *shift, long mask)
> +{
> + struct adc12138 *adc = iio_priv(iio);
> + int ret;
> + __be16 data;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
what if buffered reads have been set up? probably use
iio_device_claim_direct_mode()
> + mutex_lock(&adc->lock);
> + ret = adc12138_adc_conversion(adc, channel, &data);
> + mutex_unlock(&adc->lock);
> + if (ret)
> + return ret;
> +
> + *value = sign_extend32(be16_to_cpu(data) >> 3, 12);
> +
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + ret = regulator_get_voltage(adc->vref_p);
> + if (ret < 0)
> + return ret;
> + *value = ret;
> +
> + if (!IS_ERR(adc->vref_n)) {
> + ret = regulator_get_voltage(adc->vref_n);
> + if (ret < 0)
> + return ret;
> + *value -= ret;
> + }
> +
> + /* convert regulator output voltage to mV */
> + *value /= 1000;
> + *shift = channel->scan_type.realbits - 1;
> +
> + return IIO_VAL_FRACTIONAL_LOG2;
> + case IIO_CHAN_INFO_OFFSET:
> + if (!IS_ERR(adc->vref_n)) {
> + *value = regulator_get_voltage(adc->vref_n);
> + if (*value < 0)
> + return *value;
> + } else {
> + *value = 0;
> + }
> +
> + /* convert regulator output voltage to mV */
> + *value /= 1000;
> +
> + return IIO_VAL_INT;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static const struct iio_info adc12138_info = {
> + .read_raw = adc12138_read_raw,
> + .driver_module = THIS_MODULE,
> +};
> +
> +static int adc12138_init(struct adc12138 *adc)
> +{
> + int ret;
> + int status;
> + u8 mode;
> + u8 trash;
> +
> + reinit_completion(&adc->complete);
> +
> + ret = adc12138_mode_programming(adc, ADC12138_MODE_AUTO_CAL, &trash, 1);
> + if (ret)
> + return ret;
> +
> + /* data output at this time has no significance */
> + status = adc12138_read_status(adc);
> + if (status < 0)
> + return status;
> +
> + adc12138_wait_eoc(adc, msecs_to_jiffies(100));
> +
> + status = adc12138_read_status(adc);
> + if (status & ADC12138_STATUS_CAL) {
> + dev_warn(&adc->spi->dev,
> + "Auto Cal sequence is still in progress: %#x\n",
> + status);
> + return -EIO;
> + }
> +
> + switch (adc->acquisition_time) {
> + case 6:
> + mode = ADC12138_MODE_ACQUISITION_TIME_6;
> + break;
> + case 10:
> + mode = ADC12138_MODE_ACQUISITION_TIME_10;
> + break;
> + case 18:
> + mode = ADC12138_MODE_ACQUISITION_TIME_18;
> + break;
> + case 34:
> + mode = ADC12138_MODE_ACQUISITION_TIME_34;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return adc12138_mode_programming(adc, mode, &trash, 1);
> +}
> +
> +static irqreturn_t adc12138_trigger_handler(int irq, void *p)
> +{
> + struct iio_poll_func *pf = p;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct adc12138 *adc = iio_priv(indio_dev);
> + __be16 data[20] = { };
why { } here?
why 20?
> + __be16 trash;
> + int ret;
> + int scan_index;
> + int i = 0;
> +
> + mutex_lock(&adc->lock);
> +
> + for_each_set_bit(scan_index, indio_dev->active_scan_mask,
> + indio_dev->masklength) {
> + const struct iio_chan_spec *scan_chan =
> + &indio_dev->channels[scan_index];
> +
> + reinit_completion(&adc->complete);
> +
> + ret = adc12138_start_and_read_conv(adc, scan_chan,
> + i ? &data[i - 1] : &trash);
> + if (ret) {
> + dev_warn(&adc->spi->dev,
> + "failed to start conversion\n");
> + goto out;
> + }
> +
> + ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
> + if (ret) {
> + dev_warn(&adc->spi->dev, "wait eoc timeout\n");
> + goto out;
> + }
> +
> + i++;
> + }
> +
> + if (i) {
> + ret = adc12138_read_conv_data(adc, &data[i - 1]);
> + if (ret) {
> + dev_warn(&adc->spi->dev,
> + "failed to get conversion data\n");
> + goto out;
> + }
> + }
> +
> + iio_push_to_buffers_with_timestamp(indio_dev, data, iio_get_time_ns());
> +out:
> + mutex_unlock(&adc->lock);
> +
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t adc12138_eoc_handler(int irq, void *p)
> +{
> + struct iio_dev *indio_dev = p;
> + struct adc12138 *adc = iio_priv(indio_dev);
> +
> + complete(&adc->complete);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int adc12138_probe(struct spi_device *spi)
> +{
> + struct iio_dev *indio_dev;
> + struct adc12138 *adc;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + adc = iio_priv(indio_dev);
> + adc->spi = spi;
> + adc->id = spi_get_device_id(spi)->driver_data;
> + mutex_init(&adc->lock);
> + init_completion(&adc->complete);
> +
> + indio_dev->name = spi_get_device_id(spi)->name;
> + indio_dev->dev.parent = &spi->dev;
> + indio_dev->info = &adc12138_info;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + switch (adc->id) {
> + case adc12130:
> + case adc12132:
> + indio_dev->channels = adc12132_channels;
> + indio_dev->num_channels = ARRAY_SIZE(adc12132_channels);
> + break;
> + case adc12138:
> + indio_dev->channels = adc12138_channels;
> + indio_dev->num_channels = ARRAY_SIZE(adc12138_channels);
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + ret = of_property_read_u32(spi->dev.of_node, "acquisition-time",
> + &adc->acquisition_time);
> + if (ret)
> + adc->acquisition_time = 10;
> +
> + adc->cclk = devm_clk_get(&spi->dev, NULL);
> + if (IS_ERR(adc->cclk))
> + return PTR_ERR(adc->cclk);
> +
> + adc->vref_p = devm_regulator_get(&spi->dev, "vref-p");
> + if (IS_ERR(adc->vref_p))
> + return PTR_ERR(adc->vref_p);
> +
> + adc->vref_n = devm_regulator_get_optional(&spi->dev, "vref-n");
> +
> + ret = devm_request_irq(&spi->dev, spi->irq, adc12138_eoc_handler,
> + IRQF_TRIGGER_RISING, indio_dev->name, indio_dev);
> + if (ret)
> + return ret;
> +
> + ret = clk_prepare_enable(adc->cclk);
> + if (ret)
> + return ret;
> +
> + ret = regulator_enable(adc->vref_p);
> + if (ret)
> + goto error1;
> +
> + if (!IS_ERR(adc->vref_n)) {
> + ret = regulator_enable(adc->vref_n);
> + if (ret)
> + goto error2;
> + }
> +
> + ret = adc12138_init(adc);
> + if (ret)
> + goto error3;
> +
> + spi_set_drvdata(spi, indio_dev);
> +
> + ret = iio_triggered_buffer_setup(indio_dev, NULL,
> + adc12138_trigger_handler, NULL);
> + if (ret)
> + goto error3;
> +
> + ret = iio_device_register(indio_dev);
> + if (ret)
> + goto error4;
> +
> + return 0;
> +error4:
> + iio_triggered_buffer_cleanup(indio_dev);
> +error3:
> + if (!IS_ERR(adc->vref_n))
> + regulator_disable(adc->vref_n);
> +error2:
> + regulator_disable(adc->vref_p);
> +error1:
> + clk_disable_unprepare(adc->cclk);
> +
> + return ret;
> +}
> +
> +static int adc12138_remove(struct spi_device *spi)
> +{
> + struct iio_dev *indio_dev = spi_get_drvdata(spi);
> + struct adc12138 *adc = iio_priv(indio_dev);
> +
> + iio_device_unregister(indio_dev);
> + iio_triggered_buffer_cleanup(indio_dev);
> + if (!IS_ERR(adc->vref_n))
> + regulator_disable(adc->vref_n);
> + regulator_disable(adc->vref_p);
> + clk_disable_unprepare(adc->cclk);
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_OF
> +
> +static const struct of_device_id adc12138_dt_ids[] = {
> + { .compatible = "ti,adc12130", },
> + { .compatible = "ti,adc12132", },
> + { .compatible = "ti,adc12138", },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, adc12138_dt_ids);
> +
> +#endif
> +
> +static const struct spi_device_id adc12138_id[] = {
> + { "adc12130", adc12130 },
> + { "adc12132", adc12132 },
> + { "adc12138", adc12138 },
> + {}
> +};
> +MODULE_DEVICE_TABLE(spi, adc12138_id);
> +
> +static struct spi_driver adc12138_driver = {
> + .driver = {
> + .name = "adc12138",
> + .of_match_table = of_match_ptr(adc12138_dt_ids),
> + },
> + .probe = adc12138_probe,
> + .remove = adc12138_remove,
> + .id_table = adc12138_id,
> +};
> +module_spi_driver(adc12138_driver);
> +
> +MODULE_AUTHOR("Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
> +MODULE_DESCRIPTION("ADC12130/ADC12132/ADC12138 driver");
> +MODULE_LICENSE("GPL v2");
>
--
Peter Meerwald-Stadler
+43-664-2444418 (mobile)
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] iio: adc: add ADC12130/ADC12132/ADC12138 ADC driver
@ 2016-07-18 22:02 ` Peter Meerwald-Stadler
0 siblings, 0 replies; 10+ messages in thread
From: Peter Meerwald-Stadler @ 2016-07-18 22:02 UTC (permalink / raw)
To: Akinobu Mita
Cc: linux-iio, devicetree, Jonathan Cameron, Hartmut Knaack,
Lars-Peter Clausen
[-- Attachment #1: Type: TEXT/PLAIN, Size: 18280 bytes --]
> This adds Texas Instruments' ADC12130/ADC12132/ADC12138 12-bit plus
> sign ADC driver. I have tested with the ADC12138. The ADC12130 and
> ADC12132 are not tested but these are similar to ADC12138 except that
> the mode programming instruction is a bit different.
minor comments below
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
> Cc: Jonathan Cameron <jic23@kernel.org>
> Cc: Hartmut Knaack <knaack.h@gmx.de>
> Cc: Lars-Peter Clausen <lars@metafoo.de>
> Cc: Peter Meerwald <pmeerw@pmeerw.net>
> ---
> .../devicetree/bindings/iio/adc/ti-adc12138.txt | 32 ++
> drivers/iio/adc/Kconfig | 12 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/ti-adc12138.c | 541 +++++++++++++++++++++
> 4 files changed, 586 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
> create mode 100644 drivers/iio/adc/ti-adc12138.c
>
> diff --git a/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
> new file mode 100644
> index 0000000..3a11d2a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
> @@ -0,0 +1,32 @@
> +* Texas Instruments' ADC12130/ADC12132/ADC12138
> +
> +Required properties:
> + - compatible: Should be one of
> + * "ti,adc12130"
> + * "ti,adc12132"
> + * "ti,adc12138"
> + - reg: SPI chip select number for the device
> + - interrupts: Should contain interrupt for EOC (end of conversion)
> + - clocks: phandle to conversion clock input
> + - spi-max-frequency: Definision as per
> + Documentation/devicetree/bindings/spi/spi-bus.txt
> + - vref-p-supply: The regulator supply for positive analog voltage reference
> +
> +Optional properties:
> + - vref-n-supply: The regulator supply for negative analog voltage reference
> + If not specified, this is assumed to be analog ground.
> + - acquisition-time: The number of conversion clock periods for the S/H's
> + acquisition time. Should be one of 6, 10, 18, 34. If not specified,
> + default value of 10 is used.
> +
> +Example:
> +adc@0 {
> + compatible = "ti,adc12138";
> + reg = <0>;
> + interrupts = <28 IRQ_TYPE_EDGE_RISING>;
> + interrupt-parent = <&gpio1>;
> + clocks = <&cclk>;
> + vref-p-supply = <&ldo4_reg>;
> + spi-max-frequency = <5000000>;
> + acquisition-time = <6>;
> +};
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index fa0ff29..0783291 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -414,6 +414,18 @@ config TI_ADC0832
> This driver can also be built as a module. If so, the module will be
> called ti-adc0832.
>
> +config TI_ADC12138
> + tristate "Texas Instruments ADC12130/ADC12132/ADC12138"
> + depends on SPI
> + select IIO_BUFFER
> + select IIO_TRIGGERED_BUFFER
> + help
> + If you say yes here you get support for Texas Instruments ADC12130,
> + ADC12132and ADC12138 chips.
space before 'and' missing
> +
> + This driver can also be built as a module. If so, the module will be
> + called ti-adc12138.
> +
> config TI_ADC128S052
> tristate "Texas Instruments ADC128S052/ADC122S021/ADC124S021"
> depends on SPI
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 599714b..3ae4ae3 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -40,6 +40,7 @@ obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
> obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
> obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
> +obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o
> obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
> obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
> obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
> diff --git a/drivers/iio/adc/ti-adc12138.c b/drivers/iio/adc/ti-adc12138.c
> new file mode 100644
> index 0000000..e7bd986
> --- /dev/null
> +++ b/drivers/iio/adc/ti-adc12138.c
> @@ -0,0 +1,541 @@
> +/*
> + * ADC12130/ADC12132/ADC12138 12-bit plus sign ADC driver
> + *
> + * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>
> + *
> + * This file is subject to the terms and conditions of version 2 of
> + * the GNU General Public License. See the file COPYING in the main
> + * directory of this archive for more details.
> + *
> + * Datasheet: http://www.ti.com/lit/ds/symlink/adc12138.pdf
> + */
> +
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/completion.h>
> +#include <linux/clk.h>
> +#include <linux/spi/spi.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/regulator/consumer.h>
> +
> +#define ADC12138_MODE_AUTO_CAL 0x08
> +#define ADC12138_MODE_READ_STATUS 0x0c
> +#define ADC12138_MODE_ACQUISITION_TIME_6 0x0e
> +#define ADC12138_MODE_ACQUISITION_TIME_10 0x4e
> +#define ADC12138_MODE_ACQUISITION_TIME_18 0x8e
> +#define ADC12138_MODE_ACQUISITION_TIME_34 0xce
> +
> +#define ADC12138_STATUS_CAL BIT(6)
> +
> +enum {
> + adc12130,
> + adc12132,
> + adc12138,
> +};
> +
> +struct adc12138 {
> + struct spi_device *spi;
> + unsigned int id;
> + /* conversion clock */
> + struct clk *cclk;
> + /* positive analog voltage reference */
> + struct regulator *vref_p;
> + /* negative analog voltage reference */
> + struct regulator *vref_n;
> + struct mutex lock;
> + struct completion complete;
> + unsigned int acquisition_time;
unit? ms? µs?
> +
> + u8 tx_buf[2] ____cacheline_aligned;
> + u8 rx_buf[2];
> +};
> +
> +#define ADC12138_VOLTAGE_CHANNEL(chan) \
> + { \
> + .type = IIO_VOLTAGE, \
> + .indexed = 1, \
> + .channel = chan, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
> + | BIT(IIO_CHAN_INFO_OFFSET), \
> + .scan_index = chan, \
> + .scan_type = { \
> + .sign = 's', \
> + .realbits = 13, \
> + .storagebits = 16, \
> + .shift = 3, \
> + .endianness = IIO_BE, \
> + }, \
> + }
> +
> +#define ADC12138_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si_offset) \
> + { \
> + .type = IIO_VOLTAGE, \
> + .indexed = 1, \
> + .channel = (chan1), \
> + .channel2 = (chan2), \
> + .differential = 1, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
> + | BIT(IIO_CHAN_INFO_OFFSET), \
> + .scan_index = (chan1) + (si_offset), \
> + .scan_type = { \
> + .sign = 's', \
> + .realbits = 13, \
> + .storagebits = 16, \
> + .shift = 3, \
> + .endianness = IIO_BE, \
> + }, \
> + }
> +
> +static const struct iio_chan_spec adc12132_channels[] = {
> + ADC12138_VOLTAGE_CHANNEL(0),
> + ADC12138_VOLTAGE_CHANNEL(1),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 2),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 2),
> + IIO_CHAN_SOFT_TIMESTAMP(4),
> +};
> +
> +static const struct iio_chan_spec adc12138_channels[] = {
> + ADC12138_VOLTAGE_CHANNEL(0),
> + ADC12138_VOLTAGE_CHANNEL(1),
> + ADC12138_VOLTAGE_CHANNEL(2),
> + ADC12138_VOLTAGE_CHANNEL(3),
> + ADC12138_VOLTAGE_CHANNEL(4),
> + ADC12138_VOLTAGE_CHANNEL(5),
> + ADC12138_VOLTAGE_CHANNEL(6),
> + ADC12138_VOLTAGE_CHANNEL(7),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(2, 3, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(3, 2, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(4, 5, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(5, 4, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(6, 7, 8),
> + ADC12138_VOLTAGE_CHANNEL_DIFF(7, 6, 8),
> + IIO_CHAN_SOFT_TIMESTAMP(16),
> +};
> +
> +static int adc12138_mode_programming(struct adc12138 *adc, u8 mode,
> + void *rx_buf, int len)
> +{
> + struct spi_transfer xfer = {
> + .tx_buf = adc->tx_buf,
> + .rx_buf = adc->rx_buf,
> + .len = len,
> + };
> + int ret;
> +
> + /* Skip disused bits for ADC12130 and ADC12132 */
probably 'unused' instead of 'disused'
> + if (adc->id != adc12138)
> + mode = (mode & 0xc0) | ((mode & 0x0f) << 2);
> +
> + adc->tx_buf[0] = mode;
> +
> + ret = spi_sync_transfer(adc->spi, &xfer, 1);
> + if (ret)
> + return ret;
> +
> + memcpy(rx_buf, adc->rx_buf, len);
> +
> + return 0;
> +}
> +
> +static int adc12138_read_status(struct adc12138 *adc)
> +{
> + u8 rx_buf[2];
> + int ret;
> +
> + ret = adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
> + rx_buf, 2);
> + if (ret)
> + return ret;
> +
> + return (rx_buf[0] << 1) | (rx_buf[1] >> 7);
> +}
> +
> +static int __adc12138_start_conv(struct adc12138 *adc,
> + struct iio_chan_spec const *channel,
> + void *data, int len)
> +
> +{
> + const u8 ch_to_mux[] = { 0, 4, 1, 5, 2, 6, 3, 7 };
> + u8 mode = (ch_to_mux[channel->channel] << 4) |
> + (channel->differential ? 0 : 0x80);
> +
> + return adc12138_mode_programming(adc, mode, data, len);
> +}
> +
> +static int adc12138_start_conv(struct adc12138 *adc,
> + struct iio_chan_spec const *channel)
> +{
> + u8 trash;
> +
> + return __adc12138_start_conv(adc, channel, &trash, 1);
> +}
> +
> +static int adc12138_start_and_read_conv(struct adc12138 *adc,
> + struct iio_chan_spec const *channel,
> + __be16 *data)
> +{
> + return __adc12138_start_conv(adc, channel, data, 2);
> +}
> +
> +static int adc12138_read_conv_data(struct adc12138 *adc, __be16 *value)
> +{
> + /* Issue a read status instruction and read previous conversion data */
> + return adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
> + value, sizeof(*value));
> +}
> +
> +static int adc12138_wait_eoc(struct adc12138 *adc, unsigned long timeout)
> +{
> + if (!wait_for_completion_timeout(&adc->complete, timeout))
> + return -ETIMEDOUT;
> +
> + return 0;
> +}
> +
> +static int adc12138_adc_conversion(struct adc12138 *adc,
> + struct iio_chan_spec const *channel,
> + __be16 *value)
> +{
> + int ret;
> +
> + reinit_completion(&adc->complete);
> +
> + ret = adc12138_start_conv(adc, channel);
> + if (ret)
> + return ret;
> +
> + ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
> + if (ret)
> + return ret;
> +
> + return adc12138_read_conv_data(adc, value);
> +}
> +
> +static int adc12138_read_raw(struct iio_dev *iio,
> + struct iio_chan_spec const *channel, int *value,
> + int *shift, long mask)
> +{
> + struct adc12138 *adc = iio_priv(iio);
> + int ret;
> + __be16 data;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
what if buffered reads have been set up? probably use
iio_device_claim_direct_mode()
> + mutex_lock(&adc->lock);
> + ret = adc12138_adc_conversion(adc, channel, &data);
> + mutex_unlock(&adc->lock);
> + if (ret)
> + return ret;
> +
> + *value = sign_extend32(be16_to_cpu(data) >> 3, 12);
> +
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + ret = regulator_get_voltage(adc->vref_p);
> + if (ret < 0)
> + return ret;
> + *value = ret;
> +
> + if (!IS_ERR(adc->vref_n)) {
> + ret = regulator_get_voltage(adc->vref_n);
> + if (ret < 0)
> + return ret;
> + *value -= ret;
> + }
> +
> + /* convert regulator output voltage to mV */
> + *value /= 1000;
> + *shift = channel->scan_type.realbits - 1;
> +
> + return IIO_VAL_FRACTIONAL_LOG2;
> + case IIO_CHAN_INFO_OFFSET:
> + if (!IS_ERR(adc->vref_n)) {
> + *value = regulator_get_voltage(adc->vref_n);
> + if (*value < 0)
> + return *value;
> + } else {
> + *value = 0;
> + }
> +
> + /* convert regulator output voltage to mV */
> + *value /= 1000;
> +
> + return IIO_VAL_INT;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static const struct iio_info adc12138_info = {
> + .read_raw = adc12138_read_raw,
> + .driver_module = THIS_MODULE,
> +};
> +
> +static int adc12138_init(struct adc12138 *adc)
> +{
> + int ret;
> + int status;
> + u8 mode;
> + u8 trash;
> +
> + reinit_completion(&adc->complete);
> +
> + ret = adc12138_mode_programming(adc, ADC12138_MODE_AUTO_CAL, &trash, 1);
> + if (ret)
> + return ret;
> +
> + /* data output at this time has no significance */
> + status = adc12138_read_status(adc);
> + if (status < 0)
> + return status;
> +
> + adc12138_wait_eoc(adc, msecs_to_jiffies(100));
> +
> + status = adc12138_read_status(adc);
> + if (status & ADC12138_STATUS_CAL) {
> + dev_warn(&adc->spi->dev,
> + "Auto Cal sequence is still in progress: %#x\n",
> + status);
> + return -EIO;
> + }
> +
> + switch (adc->acquisition_time) {
> + case 6:
> + mode = ADC12138_MODE_ACQUISITION_TIME_6;
> + break;
> + case 10:
> + mode = ADC12138_MODE_ACQUISITION_TIME_10;
> + break;
> + case 18:
> + mode = ADC12138_MODE_ACQUISITION_TIME_18;
> + break;
> + case 34:
> + mode = ADC12138_MODE_ACQUISITION_TIME_34;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return adc12138_mode_programming(adc, mode, &trash, 1);
> +}
> +
> +static irqreturn_t adc12138_trigger_handler(int irq, void *p)
> +{
> + struct iio_poll_func *pf = p;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct adc12138 *adc = iio_priv(indio_dev);
> + __be16 data[20] = { };
why { } here?
why 20?
> + __be16 trash;
> + int ret;
> + int scan_index;
> + int i = 0;
> +
> + mutex_lock(&adc->lock);
> +
> + for_each_set_bit(scan_index, indio_dev->active_scan_mask,
> + indio_dev->masklength) {
> + const struct iio_chan_spec *scan_chan =
> + &indio_dev->channels[scan_index];
> +
> + reinit_completion(&adc->complete);
> +
> + ret = adc12138_start_and_read_conv(adc, scan_chan,
> + i ? &data[i - 1] : &trash);
> + if (ret) {
> + dev_warn(&adc->spi->dev,
> + "failed to start conversion\n");
> + goto out;
> + }
> +
> + ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
> + if (ret) {
> + dev_warn(&adc->spi->dev, "wait eoc timeout\n");
> + goto out;
> + }
> +
> + i++;
> + }
> +
> + if (i) {
> + ret = adc12138_read_conv_data(adc, &data[i - 1]);
> + if (ret) {
> + dev_warn(&adc->spi->dev,
> + "failed to get conversion data\n");
> + goto out;
> + }
> + }
> +
> + iio_push_to_buffers_with_timestamp(indio_dev, data, iio_get_time_ns());
> +out:
> + mutex_unlock(&adc->lock);
> +
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t adc12138_eoc_handler(int irq, void *p)
> +{
> + struct iio_dev *indio_dev = p;
> + struct adc12138 *adc = iio_priv(indio_dev);
> +
> + complete(&adc->complete);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int adc12138_probe(struct spi_device *spi)
> +{
> + struct iio_dev *indio_dev;
> + struct adc12138 *adc;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + adc = iio_priv(indio_dev);
> + adc->spi = spi;
> + adc->id = spi_get_device_id(spi)->driver_data;
> + mutex_init(&adc->lock);
> + init_completion(&adc->complete);
> +
> + indio_dev->name = spi_get_device_id(spi)->name;
> + indio_dev->dev.parent = &spi->dev;
> + indio_dev->info = &adc12138_info;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + switch (adc->id) {
> + case adc12130:
> + case adc12132:
> + indio_dev->channels = adc12132_channels;
> + indio_dev->num_channels = ARRAY_SIZE(adc12132_channels);
> + break;
> + case adc12138:
> + indio_dev->channels = adc12138_channels;
> + indio_dev->num_channels = ARRAY_SIZE(adc12138_channels);
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + ret = of_property_read_u32(spi->dev.of_node, "acquisition-time",
> + &adc->acquisition_time);
> + if (ret)
> + adc->acquisition_time = 10;
> +
> + adc->cclk = devm_clk_get(&spi->dev, NULL);
> + if (IS_ERR(adc->cclk))
> + return PTR_ERR(adc->cclk);
> +
> + adc->vref_p = devm_regulator_get(&spi->dev, "vref-p");
> + if (IS_ERR(adc->vref_p))
> + return PTR_ERR(adc->vref_p);
> +
> + adc->vref_n = devm_regulator_get_optional(&spi->dev, "vref-n");
> +
> + ret = devm_request_irq(&spi->dev, spi->irq, adc12138_eoc_handler,
> + IRQF_TRIGGER_RISING, indio_dev->name, indio_dev);
> + if (ret)
> + return ret;
> +
> + ret = clk_prepare_enable(adc->cclk);
> + if (ret)
> + return ret;
> +
> + ret = regulator_enable(adc->vref_p);
> + if (ret)
> + goto error1;
> +
> + if (!IS_ERR(adc->vref_n)) {
> + ret = regulator_enable(adc->vref_n);
> + if (ret)
> + goto error2;
> + }
> +
> + ret = adc12138_init(adc);
> + if (ret)
> + goto error3;
> +
> + spi_set_drvdata(spi, indio_dev);
> +
> + ret = iio_triggered_buffer_setup(indio_dev, NULL,
> + adc12138_trigger_handler, NULL);
> + if (ret)
> + goto error3;
> +
> + ret = iio_device_register(indio_dev);
> + if (ret)
> + goto error4;
> +
> + return 0;
> +error4:
> + iio_triggered_buffer_cleanup(indio_dev);
> +error3:
> + if (!IS_ERR(adc->vref_n))
> + regulator_disable(adc->vref_n);
> +error2:
> + regulator_disable(adc->vref_p);
> +error1:
> + clk_disable_unprepare(adc->cclk);
> +
> + return ret;
> +}
> +
> +static int adc12138_remove(struct spi_device *spi)
> +{
> + struct iio_dev *indio_dev = spi_get_drvdata(spi);
> + struct adc12138 *adc = iio_priv(indio_dev);
> +
> + iio_device_unregister(indio_dev);
> + iio_triggered_buffer_cleanup(indio_dev);
> + if (!IS_ERR(adc->vref_n))
> + regulator_disable(adc->vref_n);
> + regulator_disable(adc->vref_p);
> + clk_disable_unprepare(adc->cclk);
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_OF
> +
> +static const struct of_device_id adc12138_dt_ids[] = {
> + { .compatible = "ti,adc12130", },
> + { .compatible = "ti,adc12132", },
> + { .compatible = "ti,adc12138", },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, adc12138_dt_ids);
> +
> +#endif
> +
> +static const struct spi_device_id adc12138_id[] = {
> + { "adc12130", adc12130 },
> + { "adc12132", adc12132 },
> + { "adc12138", adc12138 },
> + {}
> +};
> +MODULE_DEVICE_TABLE(spi, adc12138_id);
> +
> +static struct spi_driver adc12138_driver = {
> + .driver = {
> + .name = "adc12138",
> + .of_match_table = of_match_ptr(adc12138_dt_ids),
> + },
> + .probe = adc12138_probe,
> + .remove = adc12138_remove,
> + .id_table = adc12138_id,
> +};
> +module_spi_driver(adc12138_driver);
> +
> +MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
> +MODULE_DESCRIPTION("ADC12130/ADC12132/ADC12138 driver");
> +MODULE_LICENSE("GPL v2");
>
--
Peter Meerwald-Stadler
+43-664-2444418 (mobile)
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] iio: adc: add ADC12130/ADC12132/ADC12138 ADC driver
2016-07-18 22:02 ` Peter Meerwald-Stadler
@ 2016-07-19 16:24 ` Akinobu Mita
-1 siblings, 0 replies; 10+ messages in thread
From: Akinobu Mita @ 2016-07-19 16:24 UTC (permalink / raw)
To: Peter Meerwald-Stadler
Cc: linux-iio-u79uwXL29TY76Z2rM5mHXA, open list:OPEN FIRMWARE AND...,
Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen
2016-07-19 7:02 GMT+09:00 Peter Meerwald-Stadler <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>:
>
>> This adds Texas Instruments' ADC12130/ADC12132/ADC12138 12-bit plus
>> sign ADC driver. I have tested with the ADC12138. The ADC12130 and
>> ADC12132 are not tested but these are similar to ADC12138 except that
>> the mode programming instruction is a bit different.
>
> minor comments below
>
>> Signed-off-by: Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> Cc: Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
>> Cc: Hartmut Knaack <knaack.h-Mmb7MZpHnFY@public.gmane.org>
>> Cc: Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>
>> Cc: Peter Meerwald <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
>> ---
>> .../devicetree/bindings/iio/adc/ti-adc12138.txt | 32 ++
>> drivers/iio/adc/Kconfig | 12 +
>> drivers/iio/adc/Makefile | 1 +
>> drivers/iio/adc/ti-adc12138.c | 541 +++++++++++++++++++++
>> 4 files changed, 586 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
>> create mode 100644 drivers/iio/adc/ti-adc12138.c
>>
>> diff --git a/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
>> new file mode 100644
>> index 0000000..3a11d2a
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
>> @@ -0,0 +1,32 @@
>> +* Texas Instruments' ADC12130/ADC12132/ADC12138
>> +
>> +Required properties:
>> + - compatible: Should be one of
>> + * "ti,adc12130"
>> + * "ti,adc12132"
>> + * "ti,adc12138"
>> + - reg: SPI chip select number for the device
>> + - interrupts: Should contain interrupt for EOC (end of conversion)
>> + - clocks: phandle to conversion clock input
>> + - spi-max-frequency: Definision as per
>> + Documentation/devicetree/bindings/spi/spi-bus.txt
>> + - vref-p-supply: The regulator supply for positive analog voltage reference
>> +
>> +Optional properties:
>> + - vref-n-supply: The regulator supply for negative analog voltage reference
>> + If not specified, this is assumed to be analog ground.
>> + - acquisition-time: The number of conversion clock periods for the S/H's
>> + acquisition time. Should be one of 6, 10, 18, 34. If not specified,
>> + default value of 10 is used.
>> +
>> +Example:
>> +adc@0 {
>> + compatible = "ti,adc12138";
>> + reg = <0>;
>> + interrupts = <28 IRQ_TYPE_EDGE_RISING>;
>> + interrupt-parent = <&gpio1>;
>> + clocks = <&cclk>;
>> + vref-p-supply = <&ldo4_reg>;
>> + spi-max-frequency = <5000000>;
>> + acquisition-time = <6>;
>> +};
>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>> index fa0ff29..0783291 100644
>> --- a/drivers/iio/adc/Kconfig
>> +++ b/drivers/iio/adc/Kconfig
>> @@ -414,6 +414,18 @@ config TI_ADC0832
>> This driver can also be built as a module. If so, the module will be
>> called ti-adc0832.
>>
>> +config TI_ADC12138
>> + tristate "Texas Instruments ADC12130/ADC12132/ADC12138"
>> + depends on SPI
>> + select IIO_BUFFER
>> + select IIO_TRIGGERED_BUFFER
>> + help
>> + If you say yes here you get support for Texas Instruments ADC12130,
>> + ADC12132and ADC12138 chips.
>
> space before 'and' missing
Ugh.
>> +
>> + This driver can also be built as a module. If so, the module will be
>> + called ti-adc12138.
>> +
>> config TI_ADC128S052
>> tristate "Texas Instruments ADC128S052/ADC122S021/ADC124S021"
>> depends on SPI
>> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
>> index 599714b..3ae4ae3 100644
>> --- a/drivers/iio/adc/Makefile
>> +++ b/drivers/iio/adc/Makefile
>> @@ -40,6 +40,7 @@ obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
>> obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
>> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
>> obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
>> +obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o
>> obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
>> obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
>> obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
>> diff --git a/drivers/iio/adc/ti-adc12138.c b/drivers/iio/adc/ti-adc12138.c
>> new file mode 100644
>> index 0000000..e7bd986
>> --- /dev/null
>> +++ b/drivers/iio/adc/ti-adc12138.c
>> @@ -0,0 +1,541 @@
>> +/*
>> + * ADC12130/ADC12132/ADC12138 12-bit plus sign ADC driver
>> + *
>> + * Copyright (c) 2016 Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> + *
>> + * This file is subject to the terms and conditions of version 2 of
>> + * the GNU General Public License. See the file COPYING in the main
>> + * directory of this archive for more details.
>> + *
>> + * Datasheet: http://www.ti.com/lit/ds/symlink/adc12138.pdf
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/completion.h>
>> +#include <linux/clk.h>
>> +#include <linux/spi/spi.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/buffer.h>
>> +#include <linux/iio/trigger.h>
>> +#include <linux/iio/triggered_buffer.h>
>> +#include <linux/iio/trigger_consumer.h>
>> +#include <linux/regulator/consumer.h>
>> +
>> +#define ADC12138_MODE_AUTO_CAL 0x08
>> +#define ADC12138_MODE_READ_STATUS 0x0c
>> +#define ADC12138_MODE_ACQUISITION_TIME_6 0x0e
>> +#define ADC12138_MODE_ACQUISITION_TIME_10 0x4e
>> +#define ADC12138_MODE_ACQUISITION_TIME_18 0x8e
>> +#define ADC12138_MODE_ACQUISITION_TIME_34 0xce
>> +
>> +#define ADC12138_STATUS_CAL BIT(6)
>> +
>> +enum {
>> + adc12130,
>> + adc12132,
>> + adc12138,
>> +};
>> +
>> +struct adc12138 {
>> + struct spi_device *spi;
>> + unsigned int id;
>> + /* conversion clock */
>> + struct clk *cclk;
>> + /* positive analog voltage reference */
>> + struct regulator *vref_p;
>> + /* negative analog voltage reference */
>> + struct regulator *vref_n;
>> + struct mutex lock;
>> + struct completion complete;
>> + unsigned int acquisition_time;
>
> unit? ms? µs?
This is specified by the number of conversion clock (cclk) periods.
I'll add a comment about it.
>> +
>> + u8 tx_buf[2] ____cacheline_aligned;
>> + u8 rx_buf[2];
>> +};
>> +
>> +#define ADC12138_VOLTAGE_CHANNEL(chan) \
>> + { \
>> + .type = IIO_VOLTAGE, \
>> + .indexed = 1, \
>> + .channel = chan, \
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
>> + | BIT(IIO_CHAN_INFO_OFFSET), \
>> + .scan_index = chan, \
>> + .scan_type = { \
>> + .sign = 's', \
>> + .realbits = 13, \
>> + .storagebits = 16, \
>> + .shift = 3, \
>> + .endianness = IIO_BE, \
>> + }, \
>> + }
>> +
>> +#define ADC12138_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si_offset) \
>> + { \
>> + .type = IIO_VOLTAGE, \
>> + .indexed = 1, \
>> + .channel = (chan1), \
>> + .channel2 = (chan2), \
>> + .differential = 1, \
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
>> + | BIT(IIO_CHAN_INFO_OFFSET), \
>> + .scan_index = (chan1) + (si_offset), \
>> + .scan_type = { \
>> + .sign = 's', \
>> + .realbits = 13, \
>> + .storagebits = 16, \
>> + .shift = 3, \
>> + .endianness = IIO_BE, \
>> + }, \
>> + }
>> +
>> +static const struct iio_chan_spec adc12132_channels[] = {
>> + ADC12138_VOLTAGE_CHANNEL(0),
>> + ADC12138_VOLTAGE_CHANNEL(1),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 2),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 2),
>> + IIO_CHAN_SOFT_TIMESTAMP(4),
>> +};
>> +
>> +static const struct iio_chan_spec adc12138_channels[] = {
>> + ADC12138_VOLTAGE_CHANNEL(0),
>> + ADC12138_VOLTAGE_CHANNEL(1),
>> + ADC12138_VOLTAGE_CHANNEL(2),
>> + ADC12138_VOLTAGE_CHANNEL(3),
>> + ADC12138_VOLTAGE_CHANNEL(4),
>> + ADC12138_VOLTAGE_CHANNEL(5),
>> + ADC12138_VOLTAGE_CHANNEL(6),
>> + ADC12138_VOLTAGE_CHANNEL(7),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(2, 3, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(3, 2, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(4, 5, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(5, 4, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(6, 7, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(7, 6, 8),
>> + IIO_CHAN_SOFT_TIMESTAMP(16),
>> +};
>> +
>> +static int adc12138_mode_programming(struct adc12138 *adc, u8 mode,
>> + void *rx_buf, int len)
>> +{
>> + struct spi_transfer xfer = {
>> + .tx_buf = adc->tx_buf,
>> + .rx_buf = adc->rx_buf,
>> + .len = len,
>> + };
>> + int ret;
>> +
>> + /* Skip disused bits for ADC12130 and ADC12132 */
>
> probably 'unused' instead of 'disused'
OK.
>> + if (adc->id != adc12138)
>> + mode = (mode & 0xc0) | ((mode & 0x0f) << 2);
>> +
>> + adc->tx_buf[0] = mode;
>> +
>> + ret = spi_sync_transfer(adc->spi, &xfer, 1);
>> + if (ret)
>> + return ret;
>> +
>> + memcpy(rx_buf, adc->rx_buf, len);
>> +
>> + return 0;
>> +}
>> +
>> +static int adc12138_read_status(struct adc12138 *adc)
>> +{
>> + u8 rx_buf[2];
>> + int ret;
>> +
>> + ret = adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
>> + rx_buf, 2);
>> + if (ret)
>> + return ret;
>> +
>> + return (rx_buf[0] << 1) | (rx_buf[1] >> 7);
>> +}
>> +
>> +static int __adc12138_start_conv(struct adc12138 *adc,
>> + struct iio_chan_spec const *channel,
>> + void *data, int len)
>> +
>> +{
>> + const u8 ch_to_mux[] = { 0, 4, 1, 5, 2, 6, 3, 7 };
>> + u8 mode = (ch_to_mux[channel->channel] << 4) |
>> + (channel->differential ? 0 : 0x80);
>> +
>> + return adc12138_mode_programming(adc, mode, data, len);
>> +}
>> +
>> +static int adc12138_start_conv(struct adc12138 *adc,
>> + struct iio_chan_spec const *channel)
>> +{
>> + u8 trash;
>> +
>> + return __adc12138_start_conv(adc, channel, &trash, 1);
>> +}
>> +
>> +static int adc12138_start_and_read_conv(struct adc12138 *adc,
>> + struct iio_chan_spec const *channel,
>> + __be16 *data)
>> +{
>> + return __adc12138_start_conv(adc, channel, data, 2);
>> +}
>> +
>> +static int adc12138_read_conv_data(struct adc12138 *adc, __be16 *value)
>> +{
>> + /* Issue a read status instruction and read previous conversion data */
>> + return adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
>> + value, sizeof(*value));
>> +}
>> +
>> +static int adc12138_wait_eoc(struct adc12138 *adc, unsigned long timeout)
>> +{
>> + if (!wait_for_completion_timeout(&adc->complete, timeout))
>> + return -ETIMEDOUT;
>> +
>> + return 0;
>> +}
>> +
>> +static int adc12138_adc_conversion(struct adc12138 *adc,
>> + struct iio_chan_spec const *channel,
>> + __be16 *value)
>> +{
>> + int ret;
>> +
>> + reinit_completion(&adc->complete);
>> +
>> + ret = adc12138_start_conv(adc, channel);
>> + if (ret)
>> + return ret;
>> +
>> + ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
>> + if (ret)
>> + return ret;
>> +
>> + return adc12138_read_conv_data(adc, value);
>> +}
>> +
>> +static int adc12138_read_raw(struct iio_dev *iio,
>> + struct iio_chan_spec const *channel, int *value,
>> + int *shift, long mask)
>> +{
>> + struct adc12138 *adc = iio_priv(iio);
>> + int ret;
>> + __be16 data;
>> +
>> + switch (mask) {
>> + case IIO_CHAN_INFO_RAW:
>
> what if buffered reads have been set up? probably use
> iio_device_claim_direct_mode()
Maybe it is safe because the ADC data is always requested and retrieved
while holding adc12138.lock from adc12138_read_raw() and
adc12138_trigger_handler(). Is it better to restrict direct mode and
return -EBUSY while buffer mode is enabled?
(BTW, I realized that I can use iio_dev->mlock instead of adc12138.lock)
>> + mutex_lock(&adc->lock);
>> + ret = adc12138_adc_conversion(adc, channel, &data);
>> + mutex_unlock(&adc->lock);
>> + if (ret)
>> + return ret;
>> +
>> + *value = sign_extend32(be16_to_cpu(data) >> 3, 12);
>> +
>> + return IIO_VAL_INT;
>> + case IIO_CHAN_INFO_SCALE:
>> + ret = regulator_get_voltage(adc->vref_p);
>> + if (ret < 0)
>> + return ret;
>> + *value = ret;
>> +
>> + if (!IS_ERR(adc->vref_n)) {
>> + ret = regulator_get_voltage(adc->vref_n);
>> + if (ret < 0)
>> + return ret;
>> + *value -= ret;
>> + }
>> +
>> + /* convert regulator output voltage to mV */
>> + *value /= 1000;
>> + *shift = channel->scan_type.realbits - 1;
>> +
>> + return IIO_VAL_FRACTIONAL_LOG2;
>> + case IIO_CHAN_INFO_OFFSET:
>> + if (!IS_ERR(adc->vref_n)) {
>> + *value = regulator_get_voltage(adc->vref_n);
>> + if (*value < 0)
>> + return *value;
>> + } else {
>> + *value = 0;
>> + }
>> +
>> + /* convert regulator output voltage to mV */
>> + *value /= 1000;
>> +
>> + return IIO_VAL_INT;
>> + }
>> +
>> + return -EINVAL;
>> +}
>> +
>> +static const struct iio_info adc12138_info = {
>> + .read_raw = adc12138_read_raw,
>> + .driver_module = THIS_MODULE,
>> +};
>> +
>> +static int adc12138_init(struct adc12138 *adc)
>> +{
>> + int ret;
>> + int status;
>> + u8 mode;
>> + u8 trash;
>> +
>> + reinit_completion(&adc->complete);
>> +
>> + ret = adc12138_mode_programming(adc, ADC12138_MODE_AUTO_CAL, &trash, 1);
>> + if (ret)
>> + return ret;
>> +
>> + /* data output at this time has no significance */
>> + status = adc12138_read_status(adc);
>> + if (status < 0)
>> + return status;
>> +
>> + adc12138_wait_eoc(adc, msecs_to_jiffies(100));
>> +
>> + status = adc12138_read_status(adc);
>> + if (status & ADC12138_STATUS_CAL) {
>> + dev_warn(&adc->spi->dev,
>> + "Auto Cal sequence is still in progress: %#x\n",
>> + status);
>> + return -EIO;
>> + }
>> +
>> + switch (adc->acquisition_time) {
>> + case 6:
>> + mode = ADC12138_MODE_ACQUISITION_TIME_6;
>> + break;
>> + case 10:
>> + mode = ADC12138_MODE_ACQUISITION_TIME_10;
>> + break;
>> + case 18:
>> + mode = ADC12138_MODE_ACQUISITION_TIME_18;
>> + break;
>> + case 34:
>> + mode = ADC12138_MODE_ACQUISITION_TIME_34;
>> + break;
>> + default:
>> + return -EINVAL;
>> + }
>> +
>> + return adc12138_mode_programming(adc, mode, &trash, 1);
>> +}
>> +
>> +static irqreturn_t adc12138_trigger_handler(int irq, void *p)
>> +{
>> + struct iio_poll_func *pf = p;
>> + struct iio_dev *indio_dev = pf->indio_dev;
>> + struct adc12138 *adc = iio_priv(indio_dev);
>> + __be16 data[20] = { };
>
> why { } here?
To initialize with zero and avoids exposing kernel stack to userspace
through padding entries. I could use memset here.
> why 20?
When all scan elements are enabled, the sample data requires 40 bytes
(2 bytes ADC data * 16 channels + 8 bytes timestamp).
I'll add comments about these.
>> + __be16 trash;
>> + int ret;
>> + int scan_index;
>> + int i = 0;
>> +
>> + mutex_lock(&adc->lock);
>> +
>> + for_each_set_bit(scan_index, indio_dev->active_scan_mask,
>> + indio_dev->masklength) {
>> + const struct iio_chan_spec *scan_chan =
>> + &indio_dev->channels[scan_index];
>> +
>> + reinit_completion(&adc->complete);
>> +
>> + ret = adc12138_start_and_read_conv(adc, scan_chan,
>> + i ? &data[i - 1] : &trash);
>> + if (ret) {
>> + dev_warn(&adc->spi->dev,
>> + "failed to start conversion\n");
>> + goto out;
>> + }
>> +
>> + ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
>> + if (ret) {
>> + dev_warn(&adc->spi->dev, "wait eoc timeout\n");
>> + goto out;
>> + }
>> +
>> + i++;
>> + }
>> +
>> + if (i) {
>> + ret = adc12138_read_conv_data(adc, &data[i - 1]);
>> + if (ret) {
>> + dev_warn(&adc->spi->dev,
>> + "failed to get conversion data\n");
>> + goto out;
>> + }
>> + }
>> +
>> + iio_push_to_buffers_with_timestamp(indio_dev, data, iio_get_time_ns());
>> +out:
>> + mutex_unlock(&adc->lock);
>> +
>> + iio_trigger_notify_done(indio_dev->trig);
>> +
>> + return IRQ_HANDLED;
>> +}
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] iio: adc: add ADC12130/ADC12132/ADC12138 ADC driver
@ 2016-07-19 16:24 ` Akinobu Mita
0 siblings, 0 replies; 10+ messages in thread
From: Akinobu Mita @ 2016-07-19 16:24 UTC (permalink / raw)
To: Peter Meerwald-Stadler
Cc: linux-iio, open list:OPEN FIRMWARE AND...,
Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen
2016-07-19 7:02 GMT+09:00 Peter Meerwald-Stadler <pmeerw@pmeerw.net>:
>
>> This adds Texas Instruments' ADC12130/ADC12132/ADC12138 12-bit plus
>> sign ADC driver. I have tested with the ADC12138. The ADC12130 and
>> ADC12132 are not tested but these are similar to ADC12138 except that
>> the mode programming instruction is a bit different.
>
> minor comments below
>
>> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
>> Cc: Jonathan Cameron <jic23@kernel.org>
>> Cc: Hartmut Knaack <knaack.h@gmx.de>
>> Cc: Lars-Peter Clausen <lars@metafoo.de>
>> Cc: Peter Meerwald <pmeerw@pmeerw.net>
>> ---
>> .../devicetree/bindings/iio/adc/ti-adc12138.txt | 32 ++
>> drivers/iio/adc/Kconfig | 12 +
>> drivers/iio/adc/Makefile | 1 +
>> drivers/iio/adc/ti-adc12138.c | 541 +++++++++++++++++++++
>> 4 files changed, 586 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
>> create mode 100644 drivers/iio/adc/ti-adc12138.c
>>
>> diff --git a/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
>> new file mode 100644
>> index 0000000..3a11d2a
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
>> @@ -0,0 +1,32 @@
>> +* Texas Instruments' ADC12130/ADC12132/ADC12138
>> +
>> +Required properties:
>> + - compatible: Should be one of
>> + * "ti,adc12130"
>> + * "ti,adc12132"
>> + * "ti,adc12138"
>> + - reg: SPI chip select number for the device
>> + - interrupts: Should contain interrupt for EOC (end of conversion)
>> + - clocks: phandle to conversion clock input
>> + - spi-max-frequency: Definision as per
>> + Documentation/devicetree/bindings/spi/spi-bus.txt
>> + - vref-p-supply: The regulator supply for positive analog voltage reference
>> +
>> +Optional properties:
>> + - vref-n-supply: The regulator supply for negative analog voltage reference
>> + If not specified, this is assumed to be analog ground.
>> + - acquisition-time: The number of conversion clock periods for the S/H's
>> + acquisition time. Should be one of 6, 10, 18, 34. If not specified,
>> + default value of 10 is used.
>> +
>> +Example:
>> +adc@0 {
>> + compatible = "ti,adc12138";
>> + reg = <0>;
>> + interrupts = <28 IRQ_TYPE_EDGE_RISING>;
>> + interrupt-parent = <&gpio1>;
>> + clocks = <&cclk>;
>> + vref-p-supply = <&ldo4_reg>;
>> + spi-max-frequency = <5000000>;
>> + acquisition-time = <6>;
>> +};
>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>> index fa0ff29..0783291 100644
>> --- a/drivers/iio/adc/Kconfig
>> +++ b/drivers/iio/adc/Kconfig
>> @@ -414,6 +414,18 @@ config TI_ADC0832
>> This driver can also be built as a module. If so, the module will be
>> called ti-adc0832.
>>
>> +config TI_ADC12138
>> + tristate "Texas Instruments ADC12130/ADC12132/ADC12138"
>> + depends on SPI
>> + select IIO_BUFFER
>> + select IIO_TRIGGERED_BUFFER
>> + help
>> + If you say yes here you get support for Texas Instruments ADC12130,
>> + ADC12132and ADC12138 chips.
>
> space before 'and' missing
Ugh.
>> +
>> + This driver can also be built as a module. If so, the module will be
>> + called ti-adc12138.
>> +
>> config TI_ADC128S052
>> tristate "Texas Instruments ADC128S052/ADC122S021/ADC124S021"
>> depends on SPI
>> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
>> index 599714b..3ae4ae3 100644
>> --- a/drivers/iio/adc/Makefile
>> +++ b/drivers/iio/adc/Makefile
>> @@ -40,6 +40,7 @@ obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
>> obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
>> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
>> obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
>> +obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o
>> obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
>> obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
>> obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
>> diff --git a/drivers/iio/adc/ti-adc12138.c b/drivers/iio/adc/ti-adc12138.c
>> new file mode 100644
>> index 0000000..e7bd986
>> --- /dev/null
>> +++ b/drivers/iio/adc/ti-adc12138.c
>> @@ -0,0 +1,541 @@
>> +/*
>> + * ADC12130/ADC12132/ADC12138 12-bit plus sign ADC driver
>> + *
>> + * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>
>> + *
>> + * This file is subject to the terms and conditions of version 2 of
>> + * the GNU General Public License. See the file COPYING in the main
>> + * directory of this archive for more details.
>> + *
>> + * Datasheet: http://www.ti.com/lit/ds/symlink/adc12138.pdf
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/completion.h>
>> +#include <linux/clk.h>
>> +#include <linux/spi/spi.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/buffer.h>
>> +#include <linux/iio/trigger.h>
>> +#include <linux/iio/triggered_buffer.h>
>> +#include <linux/iio/trigger_consumer.h>
>> +#include <linux/regulator/consumer.h>
>> +
>> +#define ADC12138_MODE_AUTO_CAL 0x08
>> +#define ADC12138_MODE_READ_STATUS 0x0c
>> +#define ADC12138_MODE_ACQUISITION_TIME_6 0x0e
>> +#define ADC12138_MODE_ACQUISITION_TIME_10 0x4e
>> +#define ADC12138_MODE_ACQUISITION_TIME_18 0x8e
>> +#define ADC12138_MODE_ACQUISITION_TIME_34 0xce
>> +
>> +#define ADC12138_STATUS_CAL BIT(6)
>> +
>> +enum {
>> + adc12130,
>> + adc12132,
>> + adc12138,
>> +};
>> +
>> +struct adc12138 {
>> + struct spi_device *spi;
>> + unsigned int id;
>> + /* conversion clock */
>> + struct clk *cclk;
>> + /* positive analog voltage reference */
>> + struct regulator *vref_p;
>> + /* negative analog voltage reference */
>> + struct regulator *vref_n;
>> + struct mutex lock;
>> + struct completion complete;
>> + unsigned int acquisition_time;
>
> unit? ms? µs?
This is specified by the number of conversion clock (cclk) periods.
I'll add a comment about it.
>> +
>> + u8 tx_buf[2] ____cacheline_aligned;
>> + u8 rx_buf[2];
>> +};
>> +
>> +#define ADC12138_VOLTAGE_CHANNEL(chan) \
>> + { \
>> + .type = IIO_VOLTAGE, \
>> + .indexed = 1, \
>> + .channel = chan, \
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
>> + | BIT(IIO_CHAN_INFO_OFFSET), \
>> + .scan_index = chan, \
>> + .scan_type = { \
>> + .sign = 's', \
>> + .realbits = 13, \
>> + .storagebits = 16, \
>> + .shift = 3, \
>> + .endianness = IIO_BE, \
>> + }, \
>> + }
>> +
>> +#define ADC12138_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si_offset) \
>> + { \
>> + .type = IIO_VOLTAGE, \
>> + .indexed = 1, \
>> + .channel = (chan1), \
>> + .channel2 = (chan2), \
>> + .differential = 1, \
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
>> + | BIT(IIO_CHAN_INFO_OFFSET), \
>> + .scan_index = (chan1) + (si_offset), \
>> + .scan_type = { \
>> + .sign = 's', \
>> + .realbits = 13, \
>> + .storagebits = 16, \
>> + .shift = 3, \
>> + .endianness = IIO_BE, \
>> + }, \
>> + }
>> +
>> +static const struct iio_chan_spec adc12132_channels[] = {
>> + ADC12138_VOLTAGE_CHANNEL(0),
>> + ADC12138_VOLTAGE_CHANNEL(1),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 2),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 2),
>> + IIO_CHAN_SOFT_TIMESTAMP(4),
>> +};
>> +
>> +static const struct iio_chan_spec adc12138_channels[] = {
>> + ADC12138_VOLTAGE_CHANNEL(0),
>> + ADC12138_VOLTAGE_CHANNEL(1),
>> + ADC12138_VOLTAGE_CHANNEL(2),
>> + ADC12138_VOLTAGE_CHANNEL(3),
>> + ADC12138_VOLTAGE_CHANNEL(4),
>> + ADC12138_VOLTAGE_CHANNEL(5),
>> + ADC12138_VOLTAGE_CHANNEL(6),
>> + ADC12138_VOLTAGE_CHANNEL(7),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(2, 3, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(3, 2, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(4, 5, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(5, 4, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(6, 7, 8),
>> + ADC12138_VOLTAGE_CHANNEL_DIFF(7, 6, 8),
>> + IIO_CHAN_SOFT_TIMESTAMP(16),
>> +};
>> +
>> +static int adc12138_mode_programming(struct adc12138 *adc, u8 mode,
>> + void *rx_buf, int len)
>> +{
>> + struct spi_transfer xfer = {
>> + .tx_buf = adc->tx_buf,
>> + .rx_buf = adc->rx_buf,
>> + .len = len,
>> + };
>> + int ret;
>> +
>> + /* Skip disused bits for ADC12130 and ADC12132 */
>
> probably 'unused' instead of 'disused'
OK.
>> + if (adc->id != adc12138)
>> + mode = (mode & 0xc0) | ((mode & 0x0f) << 2);
>> +
>> + adc->tx_buf[0] = mode;
>> +
>> + ret = spi_sync_transfer(adc->spi, &xfer, 1);
>> + if (ret)
>> + return ret;
>> +
>> + memcpy(rx_buf, adc->rx_buf, len);
>> +
>> + return 0;
>> +}
>> +
>> +static int adc12138_read_status(struct adc12138 *adc)
>> +{
>> + u8 rx_buf[2];
>> + int ret;
>> +
>> + ret = adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
>> + rx_buf, 2);
>> + if (ret)
>> + return ret;
>> +
>> + return (rx_buf[0] << 1) | (rx_buf[1] >> 7);
>> +}
>> +
>> +static int __adc12138_start_conv(struct adc12138 *adc,
>> + struct iio_chan_spec const *channel,
>> + void *data, int len)
>> +
>> +{
>> + const u8 ch_to_mux[] = { 0, 4, 1, 5, 2, 6, 3, 7 };
>> + u8 mode = (ch_to_mux[channel->channel] << 4) |
>> + (channel->differential ? 0 : 0x80);
>> +
>> + return adc12138_mode_programming(adc, mode, data, len);
>> +}
>> +
>> +static int adc12138_start_conv(struct adc12138 *adc,
>> + struct iio_chan_spec const *channel)
>> +{
>> + u8 trash;
>> +
>> + return __adc12138_start_conv(adc, channel, &trash, 1);
>> +}
>> +
>> +static int adc12138_start_and_read_conv(struct adc12138 *adc,
>> + struct iio_chan_spec const *channel,
>> + __be16 *data)
>> +{
>> + return __adc12138_start_conv(adc, channel, data, 2);
>> +}
>> +
>> +static int adc12138_read_conv_data(struct adc12138 *adc, __be16 *value)
>> +{
>> + /* Issue a read status instruction and read previous conversion data */
>> + return adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
>> + value, sizeof(*value));
>> +}
>> +
>> +static int adc12138_wait_eoc(struct adc12138 *adc, unsigned long timeout)
>> +{
>> + if (!wait_for_completion_timeout(&adc->complete, timeout))
>> + return -ETIMEDOUT;
>> +
>> + return 0;
>> +}
>> +
>> +static int adc12138_adc_conversion(struct adc12138 *adc,
>> + struct iio_chan_spec const *channel,
>> + __be16 *value)
>> +{
>> + int ret;
>> +
>> + reinit_completion(&adc->complete);
>> +
>> + ret = adc12138_start_conv(adc, channel);
>> + if (ret)
>> + return ret;
>> +
>> + ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
>> + if (ret)
>> + return ret;
>> +
>> + return adc12138_read_conv_data(adc, value);
>> +}
>> +
>> +static int adc12138_read_raw(struct iio_dev *iio,
>> + struct iio_chan_spec const *channel, int *value,
>> + int *shift, long mask)
>> +{
>> + struct adc12138 *adc = iio_priv(iio);
>> + int ret;
>> + __be16 data;
>> +
>> + switch (mask) {
>> + case IIO_CHAN_INFO_RAW:
>
> what if buffered reads have been set up? probably use
> iio_device_claim_direct_mode()
Maybe it is safe because the ADC data is always requested and retrieved
while holding adc12138.lock from adc12138_read_raw() and
adc12138_trigger_handler(). Is it better to restrict direct mode and
return -EBUSY while buffer mode is enabled?
(BTW, I realized that I can use iio_dev->mlock instead of adc12138.lock)
>> + mutex_lock(&adc->lock);
>> + ret = adc12138_adc_conversion(adc, channel, &data);
>> + mutex_unlock(&adc->lock);
>> + if (ret)
>> + return ret;
>> +
>> + *value = sign_extend32(be16_to_cpu(data) >> 3, 12);
>> +
>> + return IIO_VAL_INT;
>> + case IIO_CHAN_INFO_SCALE:
>> + ret = regulator_get_voltage(adc->vref_p);
>> + if (ret < 0)
>> + return ret;
>> + *value = ret;
>> +
>> + if (!IS_ERR(adc->vref_n)) {
>> + ret = regulator_get_voltage(adc->vref_n);
>> + if (ret < 0)
>> + return ret;
>> + *value -= ret;
>> + }
>> +
>> + /* convert regulator output voltage to mV */
>> + *value /= 1000;
>> + *shift = channel->scan_type.realbits - 1;
>> +
>> + return IIO_VAL_FRACTIONAL_LOG2;
>> + case IIO_CHAN_INFO_OFFSET:
>> + if (!IS_ERR(adc->vref_n)) {
>> + *value = regulator_get_voltage(adc->vref_n);
>> + if (*value < 0)
>> + return *value;
>> + } else {
>> + *value = 0;
>> + }
>> +
>> + /* convert regulator output voltage to mV */
>> + *value /= 1000;
>> +
>> + return IIO_VAL_INT;
>> + }
>> +
>> + return -EINVAL;
>> +}
>> +
>> +static const struct iio_info adc12138_info = {
>> + .read_raw = adc12138_read_raw,
>> + .driver_module = THIS_MODULE,
>> +};
>> +
>> +static int adc12138_init(struct adc12138 *adc)
>> +{
>> + int ret;
>> + int status;
>> + u8 mode;
>> + u8 trash;
>> +
>> + reinit_completion(&adc->complete);
>> +
>> + ret = adc12138_mode_programming(adc, ADC12138_MODE_AUTO_CAL, &trash, 1);
>> + if (ret)
>> + return ret;
>> +
>> + /* data output at this time has no significance */
>> + status = adc12138_read_status(adc);
>> + if (status < 0)
>> + return status;
>> +
>> + adc12138_wait_eoc(adc, msecs_to_jiffies(100));
>> +
>> + status = adc12138_read_status(adc);
>> + if (status & ADC12138_STATUS_CAL) {
>> + dev_warn(&adc->spi->dev,
>> + "Auto Cal sequence is still in progress: %#x\n",
>> + status);
>> + return -EIO;
>> + }
>> +
>> + switch (adc->acquisition_time) {
>> + case 6:
>> + mode = ADC12138_MODE_ACQUISITION_TIME_6;
>> + break;
>> + case 10:
>> + mode = ADC12138_MODE_ACQUISITION_TIME_10;
>> + break;
>> + case 18:
>> + mode = ADC12138_MODE_ACQUISITION_TIME_18;
>> + break;
>> + case 34:
>> + mode = ADC12138_MODE_ACQUISITION_TIME_34;
>> + break;
>> + default:
>> + return -EINVAL;
>> + }
>> +
>> + return adc12138_mode_programming(adc, mode, &trash, 1);
>> +}
>> +
>> +static irqreturn_t adc12138_trigger_handler(int irq, void *p)
>> +{
>> + struct iio_poll_func *pf = p;
>> + struct iio_dev *indio_dev = pf->indio_dev;
>> + struct adc12138 *adc = iio_priv(indio_dev);
>> + __be16 data[20] = { };
>
> why { } here?
To initialize with zero and avoids exposing kernel stack to userspace
through padding entries. I could use memset here.
> why 20?
When all scan elements are enabled, the sample data requires 40 bytes
(2 bytes ADC data * 16 channels + 8 bytes timestamp).
I'll add comments about these.
>> + __be16 trash;
>> + int ret;
>> + int scan_index;
>> + int i = 0;
>> +
>> + mutex_lock(&adc->lock);
>> +
>> + for_each_set_bit(scan_index, indio_dev->active_scan_mask,
>> + indio_dev->masklength) {
>> + const struct iio_chan_spec *scan_chan =
>> + &indio_dev->channels[scan_index];
>> +
>> + reinit_completion(&adc->complete);
>> +
>> + ret = adc12138_start_and_read_conv(adc, scan_chan,
>> + i ? &data[i - 1] : &trash);
>> + if (ret) {
>> + dev_warn(&adc->spi->dev,
>> + "failed to start conversion\n");
>> + goto out;
>> + }
>> +
>> + ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
>> + if (ret) {
>> + dev_warn(&adc->spi->dev, "wait eoc timeout\n");
>> + goto out;
>> + }
>> +
>> + i++;
>> + }
>> +
>> + if (i) {
>> + ret = adc12138_read_conv_data(adc, &data[i - 1]);
>> + if (ret) {
>> + dev_warn(&adc->spi->dev,
>> + "failed to get conversion data\n");
>> + goto out;
>> + }
>> + }
>> +
>> + iio_push_to_buffers_with_timestamp(indio_dev, data, iio_get_time_ns());
>> +out:
>> + mutex_unlock(&adc->lock);
>> +
>> + iio_trigger_notify_done(indio_dev->trig);
>> +
>> + return IRQ_HANDLED;
>> +}
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] iio: adc: add ADC12130/ADC12132/ADC12138 ADC driver
2016-07-18 15:00 ` Akinobu Mita
@ 2016-07-20 1:11 ` Rob Herring
-1 siblings, 0 replies; 10+ messages in thread
From: Rob Herring @ 2016-07-20 1:11 UTC (permalink / raw)
To: Akinobu Mita
Cc: linux-iio-u79uwXL29TY76Z2rM5mHXA,
devicetree-u79uwXL29TY76Z2rM5mHXA, Jonathan Cameron,
Hartmut Knaack, Lars-Peter Clausen, Peter Meerwald
On Tue, Jul 19, 2016 at 12:00:29AM +0900, Akinobu Mita wrote:
> This adds Texas Instruments' ADC12130/ADC12132/ADC12138 12-bit plus
> sign ADC driver. I have tested with the ADC12138. The ADC12130 and
> ADC12132 are not tested but these are similar to ADC12138 except that
> the mode programming instruction is a bit different.
>
> Signed-off-by: Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Cc: Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Cc: Hartmut Knaack <knaack.h-Mmb7MZpHnFY@public.gmane.org>
> Cc: Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>
> Cc: Peter Meerwald <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
> ---
> .../devicetree/bindings/iio/adc/ti-adc12138.txt | 32 ++
Acked-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> drivers/iio/adc/Kconfig | 12 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/ti-adc12138.c | 541 +++++++++++++++++++++
> 4 files changed, 586 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
> create mode 100644 drivers/iio/adc/ti-adc12138.c
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] iio: adc: add ADC12130/ADC12132/ADC12138 ADC driver
@ 2016-07-20 1:11 ` Rob Herring
0 siblings, 0 replies; 10+ messages in thread
From: Rob Herring @ 2016-07-20 1:11 UTC (permalink / raw)
To: Akinobu Mita
Cc: linux-iio, devicetree, Jonathan Cameron, Hartmut Knaack,
Lars-Peter Clausen, Peter Meerwald
On Tue, Jul 19, 2016 at 12:00:29AM +0900, Akinobu Mita wrote:
> This adds Texas Instruments' ADC12130/ADC12132/ADC12138 12-bit plus
> sign ADC driver. I have tested with the ADC12138. The ADC12130 and
> ADC12132 are not tested but these are similar to ADC12138 except that
> the mode programming instruction is a bit different.
>
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
> Cc: Jonathan Cameron <jic23@kernel.org>
> Cc: Hartmut Knaack <knaack.h@gmx.de>
> Cc: Lars-Peter Clausen <lars@metafoo.de>
> Cc: Peter Meerwald <pmeerw@pmeerw.net>
> ---
> .../devicetree/bindings/iio/adc/ti-adc12138.txt | 32 ++
Acked-by: Rob Herring <robh@kernel.org>
> drivers/iio/adc/Kconfig | 12 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/ti-adc12138.c | 541 +++++++++++++++++++++
> 4 files changed, 586 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
> create mode 100644 drivers/iio/adc/ti-adc12138.c
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] iio: adc: add ADC12130/ADC12132/ADC12138 ADC driver
2016-07-19 16:24 ` Akinobu Mita
@ 2016-07-20 15:05 ` Jonathan Cameron
-1 siblings, 0 replies; 10+ messages in thread
From: Jonathan Cameron @ 2016-07-20 15:05 UTC (permalink / raw)
To: Akinobu Mita, Peter Meerwald-Stadler
Cc: linux-iio-u79uwXL29TY76Z2rM5mHXA, open list:OPEN FIRMWARE AND...,
Hartmut Knaack, Lars-Peter Clausen
On 19/07/16 17:24, Akinobu Mita wrote:
> 2016-07-19 7:02 GMT+09:00 Peter Meerwald-Stadler <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>:
>>
>>> This adds Texas Instruments' ADC12130/ADC12132/ADC12138 12-bit plus
>>> sign ADC driver. I have tested with the ADC12138. The ADC12130 and
>>> ADC12132 are not tested but these are similar to ADC12138 except that
>>> the mode programming instruction is a bit different.
>>
>> minor comments below
>>
>>> Signed-off-by: Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>>> Cc: Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
>>> Cc: Hartmut Knaack <knaack.h-Mmb7MZpHnFY@public.gmane.org>
>>> Cc: Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>
>>> Cc: Peter Meerwald <pmeerw-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
>>> ---
>>> .../devicetree/bindings/iio/adc/ti-adc12138.txt | 32 ++
>>> drivers/iio/adc/Kconfig | 12 +
>>> drivers/iio/adc/Makefile | 1 +
>>> drivers/iio/adc/ti-adc12138.c | 541 +++++++++++++++++++++
>>> 4 files changed, 586 insertions(+)
>>> create mode 100644 Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
>>> create mode 100644 drivers/iio/adc/ti-adc12138.c
>>>
>>> diff --git a/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
>>> new file mode 100644
>>> index 0000000..3a11d2a
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
>>> @@ -0,0 +1,32 @@
>>> +* Texas Instruments' ADC12130/ADC12132/ADC12138
>>> +
>>> +Required properties:
>>> + - compatible: Should be one of
>>> + * "ti,adc12130"
>>> + * "ti,adc12132"
>>> + * "ti,adc12138"
>>> + - reg: SPI chip select number for the device
>>> + - interrupts: Should contain interrupt for EOC (end of conversion)
>>> + - clocks: phandle to conversion clock input
>>> + - spi-max-frequency: Definision as per
>>> + Documentation/devicetree/bindings/spi/spi-bus.txt
>>> + - vref-p-supply: The regulator supply for positive analog voltage reference
>>> +
>>> +Optional properties:
>>> + - vref-n-supply: The regulator supply for negative analog voltage reference
>>> + If not specified, this is assumed to be analog ground.
>>> + - acquisition-time: The number of conversion clock periods for the S/H's
>>> + acquisition time. Should be one of 6, 10, 18, 34. If not specified,
>>> + default value of 10 is used.
>>> +
>>> +Example:
>>> +adc@0 {
>>> + compatible = "ti,adc12138";
>>> + reg = <0>;
>>> + interrupts = <28 IRQ_TYPE_EDGE_RISING>;
>>> + interrupt-parent = <&gpio1>;
>>> + clocks = <&cclk>;
>>> + vref-p-supply = <&ldo4_reg>;
>>> + spi-max-frequency = <5000000>;
>>> + acquisition-time = <6>;
>>> +};
>>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>>> index fa0ff29..0783291 100644
>>> --- a/drivers/iio/adc/Kconfig
>>> +++ b/drivers/iio/adc/Kconfig
>>> @@ -414,6 +414,18 @@ config TI_ADC0832
>>> This driver can also be built as a module. If so, the module will be
>>> called ti-adc0832.
>>>
>>> +config TI_ADC12138
>>> + tristate "Texas Instruments ADC12130/ADC12132/ADC12138"
>>> + depends on SPI
>>> + select IIO_BUFFER
>>> + select IIO_TRIGGERED_BUFFER
>>> + help
>>> + If you say yes here you get support for Texas Instruments ADC12130,
>>> + ADC12132and ADC12138 chips.
>>
>> space before 'and' missing
>
> Ugh.
>
>>> +
>>> + This driver can also be built as a module. If so, the module will be
>>> + called ti-adc12138.
>>> +
>>> config TI_ADC128S052
>>> tristate "Texas Instruments ADC128S052/ADC122S021/ADC124S021"
>>> depends on SPI
>>> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
>>> index 599714b..3ae4ae3 100644
>>> --- a/drivers/iio/adc/Makefile
>>> +++ b/drivers/iio/adc/Makefile
>>> @@ -40,6 +40,7 @@ obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
>>> obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
>>> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
>>> obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
>>> +obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o
>>> obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
>>> obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
>>> obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
>>> diff --git a/drivers/iio/adc/ti-adc12138.c b/drivers/iio/adc/ti-adc12138.c
>>> new file mode 100644
>>> index 0000000..e7bd986
>>> --- /dev/null
>>> +++ b/drivers/iio/adc/ti-adc12138.c
>>> @@ -0,0 +1,541 @@
>>> +/*
>>> + * ADC12130/ADC12132/ADC12138 12-bit plus sign ADC driver
>>> + *
>>> + * Copyright (c) 2016 Akinobu Mita <akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>>> + *
>>> + * This file is subject to the terms and conditions of version 2 of
>>> + * the GNU General Public License. See the file COPYING in the main
>>> + * directory of this archive for more details.
>>> + *
>>> + * Datasheet: http://www.ti.com/lit/ds/symlink/adc12138.pdf
>>> + */
>>> +
>>> +#include <linux/module.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/completion.h>
>>> +#include <linux/clk.h>
>>> +#include <linux/spi/spi.h>
>>> +#include <linux/iio/iio.h>
>>> +#include <linux/iio/buffer.h>
>>> +#include <linux/iio/trigger.h>
>>> +#include <linux/iio/triggered_buffer.h>
>>> +#include <linux/iio/trigger_consumer.h>
>>> +#include <linux/regulator/consumer.h>
>>> +
>>> +#define ADC12138_MODE_AUTO_CAL 0x08
>>> +#define ADC12138_MODE_READ_STATUS 0x0c
>>> +#define ADC12138_MODE_ACQUISITION_TIME_6 0x0e
>>> +#define ADC12138_MODE_ACQUISITION_TIME_10 0x4e
>>> +#define ADC12138_MODE_ACQUISITION_TIME_18 0x8e
>>> +#define ADC12138_MODE_ACQUISITION_TIME_34 0xce
>>> +
>>> +#define ADC12138_STATUS_CAL BIT(6)
>>> +
>>> +enum {
>>> + adc12130,
>>> + adc12132,
>>> + adc12138,
>>> +};
>>> +
>>> +struct adc12138 {
>>> + struct spi_device *spi;
>>> + unsigned int id;
>>> + /* conversion clock */
>>> + struct clk *cclk;
>>> + /* positive analog voltage reference */
>>> + struct regulator *vref_p;
>>> + /* negative analog voltage reference */
>>> + struct regulator *vref_n;
>>> + struct mutex lock;
>>> + struct completion complete;
>>> + unsigned int acquisition_time;
>>
>> unit? ms? µs?
>
> This is specified by the number of conversion clock (cclk) periods.
> I'll add a comment about it.
>
>>> +
>>> + u8 tx_buf[2] ____cacheline_aligned;
>>> + u8 rx_buf[2];
>>> +};
>>> +
>>> +#define ADC12138_VOLTAGE_CHANNEL(chan) \
>>> + { \
>>> + .type = IIO_VOLTAGE, \
>>> + .indexed = 1, \
>>> + .channel = chan, \
>>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>>> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
>>> + | BIT(IIO_CHAN_INFO_OFFSET), \
>>> + .scan_index = chan, \
>>> + .scan_type = { \
>>> + .sign = 's', \
>>> + .realbits = 13, \
>>> + .storagebits = 16, \
>>> + .shift = 3, \
>>> + .endianness = IIO_BE, \
>>> + }, \
>>> + }
>>> +
>>> +#define ADC12138_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si_offset) \
>>> + { \
>>> + .type = IIO_VOLTAGE, \
>>> + .indexed = 1, \
>>> + .channel = (chan1), \
>>> + .channel2 = (chan2), \
>>> + .differential = 1, \
>>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>>> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
>>> + | BIT(IIO_CHAN_INFO_OFFSET), \
>>> + .scan_index = (chan1) + (si_offset), \
>>> + .scan_type = { \
>>> + .sign = 's', \
>>> + .realbits = 13, \
>>> + .storagebits = 16, \
>>> + .shift = 3, \
>>> + .endianness = IIO_BE, \
>>> + }, \
>>> + }
>>> +
>>> +static const struct iio_chan_spec adc12132_channels[] = {
>>> + ADC12138_VOLTAGE_CHANNEL(0),
>>> + ADC12138_VOLTAGE_CHANNEL(1),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 2),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 2),
>>> + IIO_CHAN_SOFT_TIMESTAMP(4),
>>> +};
>>> +
>>> +static const struct iio_chan_spec adc12138_channels[] = {
>>> + ADC12138_VOLTAGE_CHANNEL(0),
>>> + ADC12138_VOLTAGE_CHANNEL(1),
>>> + ADC12138_VOLTAGE_CHANNEL(2),
>>> + ADC12138_VOLTAGE_CHANNEL(3),
>>> + ADC12138_VOLTAGE_CHANNEL(4),
>>> + ADC12138_VOLTAGE_CHANNEL(5),
>>> + ADC12138_VOLTAGE_CHANNEL(6),
>>> + ADC12138_VOLTAGE_CHANNEL(7),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(2, 3, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(3, 2, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(4, 5, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(5, 4, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(6, 7, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(7, 6, 8),
>>> + IIO_CHAN_SOFT_TIMESTAMP(16),
>>> +};
>>> +
>>> +static int adc12138_mode_programming(struct adc12138 *adc, u8 mode,
>>> + void *rx_buf, int len)
>>> +{
>>> + struct spi_transfer xfer = {
>>> + .tx_buf = adc->tx_buf,
>>> + .rx_buf = adc->rx_buf,
>>> + .len = len,
>>> + };
>>> + int ret;
>>> +
>>> + /* Skip disused bits for ADC12130 and ADC12132 */
>>
>> probably 'unused' instead of 'disused'
>
> OK.
>
>>> + if (adc->id != adc12138)
>>> + mode = (mode & 0xc0) | ((mode & 0x0f) << 2);
>>> +
>>> + adc->tx_buf[0] = mode;
>>> +
>>> + ret = spi_sync_transfer(adc->spi, &xfer, 1);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + memcpy(rx_buf, adc->rx_buf, len);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int adc12138_read_status(struct adc12138 *adc)
>>> +{
>>> + u8 rx_buf[2];
>>> + int ret;
>>> +
>>> + ret = adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
>>> + rx_buf, 2);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + return (rx_buf[0] << 1) | (rx_buf[1] >> 7);
>>> +}
>>> +
>>> +static int __adc12138_start_conv(struct adc12138 *adc,
>>> + struct iio_chan_spec const *channel,
>>> + void *data, int len)
>>> +
>>> +{
>>> + const u8 ch_to_mux[] = { 0, 4, 1, 5, 2, 6, 3, 7 };
>>> + u8 mode = (ch_to_mux[channel->channel] << 4) |
>>> + (channel->differential ? 0 : 0x80);
>>> +
>>> + return adc12138_mode_programming(adc, mode, data, len);
>>> +}
>>> +
>>> +static int adc12138_start_conv(struct adc12138 *adc,
>>> + struct iio_chan_spec const *channel)
>>> +{
>>> + u8 trash;
>>> +
>>> + return __adc12138_start_conv(adc, channel, &trash, 1);
>>> +}
>>> +
>>> +static int adc12138_start_and_read_conv(struct adc12138 *adc,
>>> + struct iio_chan_spec const *channel,
>>> + __be16 *data)
>>> +{
>>> + return __adc12138_start_conv(adc, channel, data, 2);
>>> +}
>>> +
>>> +static int adc12138_read_conv_data(struct adc12138 *adc, __be16 *value)
>>> +{
>>> + /* Issue a read status instruction and read previous conversion data */
>>> + return adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
>>> + value, sizeof(*value));
>>> +}
>>> +
>>> +static int adc12138_wait_eoc(struct adc12138 *adc, unsigned long timeout)
>>> +{
>>> + if (!wait_for_completion_timeout(&adc->complete, timeout))
>>> + return -ETIMEDOUT;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int adc12138_adc_conversion(struct adc12138 *adc,
>>> + struct iio_chan_spec const *channel,
>>> + __be16 *value)
>>> +{
>>> + int ret;
>>> +
>>> + reinit_completion(&adc->complete);
>>> +
>>> + ret = adc12138_start_conv(adc, channel);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
>>> + if (ret)
>>> + return ret;
>>> +
>>> + return adc12138_read_conv_data(adc, value);
>>> +}
>>> +
>>> +static int adc12138_read_raw(struct iio_dev *iio,
>>> + struct iio_chan_spec const *channel, int *value,
>>> + int *shift, long mask)
>>> +{
>>> + struct adc12138 *adc = iio_priv(iio);
>>> + int ret;
>>> + __be16 data;
>>> +
>>> + switch (mask) {
>>> + case IIO_CHAN_INFO_RAW:
>>
>> what if buffered reads have been set up? probably use
>> iio_device_claim_direct_mode()
>
> Maybe it is safe because the ADC data is always requested and retrieved
> while holding adc12138.lock from adc12138_read_raw() and
> adc12138_trigger_handler(). Is it better to restrict direct mode and
> return -EBUSY while buffer mode is enabled?
>
> (BTW, I realized that I can use iio_dev->mlock instead of adc12138.lock)
Don't use it for anything other than state change locking. It has that
well focused task within the subsystem - we are trying to clear out other
uses entirely as there have been more than a few bugs around this.
Much better to have a separate lock for protecting resources controlled
directly by the driver itself.
>
>>> + mutex_lock(&adc->lock);
>>> + ret = adc12138_adc_conversion(adc, channel, &data);
>>> + mutex_unlock(&adc->lock);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + *value = sign_extend32(be16_to_cpu(data) >> 3, 12);
>>> +
>>> + return IIO_VAL_INT;
>>> + case IIO_CHAN_INFO_SCALE:
>>> + ret = regulator_get_voltage(adc->vref_p);
>>> + if (ret < 0)
>>> + return ret;
>>> + *value = ret;
>>> +
>>> + if (!IS_ERR(adc->vref_n)) {
>>> + ret = regulator_get_voltage(adc->vref_n);
>>> + if (ret < 0)
>>> + return ret;
>>> + *value -= ret;
>>> + }
>>> +
>>> + /* convert regulator output voltage to mV */
>>> + *value /= 1000;
>>> + *shift = channel->scan_type.realbits - 1;
>>> +
>>> + return IIO_VAL_FRACTIONAL_LOG2;
>>> + case IIO_CHAN_INFO_OFFSET:
>>> + if (!IS_ERR(adc->vref_n)) {
>>> + *value = regulator_get_voltage(adc->vref_n);
>>> + if (*value < 0)
>>> + return *value;
>>> + } else {
>>> + *value = 0;
>>> + }
>>> +
>>> + /* convert regulator output voltage to mV */
>>> + *value /= 1000;
>>> +
>>> + return IIO_VAL_INT;
>>> + }
>>> +
>>> + return -EINVAL;
>>> +}
>>> +
>>> +static const struct iio_info adc12138_info = {
>>> + .read_raw = adc12138_read_raw,
>>> + .driver_module = THIS_MODULE,
>>> +};
>>> +
>>> +static int adc12138_init(struct adc12138 *adc)
>>> +{
>>> + int ret;
>>> + int status;
>>> + u8 mode;
>>> + u8 trash;
>>> +
>>> + reinit_completion(&adc->complete);
>>> +
>>> + ret = adc12138_mode_programming(adc, ADC12138_MODE_AUTO_CAL, &trash, 1);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + /* data output at this time has no significance */
>>> + status = adc12138_read_status(adc);
>>> + if (status < 0)
>>> + return status;
>>> +
>>> + adc12138_wait_eoc(adc, msecs_to_jiffies(100));
>>> +
>>> + status = adc12138_read_status(adc);
>>> + if (status & ADC12138_STATUS_CAL) {
>>> + dev_warn(&adc->spi->dev,
>>> + "Auto Cal sequence is still in progress: %#x\n",
>>> + status);
>>> + return -EIO;
>>> + }
>>> +
>>> + switch (adc->acquisition_time) {
>>> + case 6:
>>> + mode = ADC12138_MODE_ACQUISITION_TIME_6;
>>> + break;
>>> + case 10:
>>> + mode = ADC12138_MODE_ACQUISITION_TIME_10;
>>> + break;
>>> + case 18:
>>> + mode = ADC12138_MODE_ACQUISITION_TIME_18;
>>> + break;
>>> + case 34:
>>> + mode = ADC12138_MODE_ACQUISITION_TIME_34;
>>> + break;
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> +
>>> + return adc12138_mode_programming(adc, mode, &trash, 1);
>>> +}
>>> +
>>> +static irqreturn_t adc12138_trigger_handler(int irq, void *p)
>>> +{
>>> + struct iio_poll_func *pf = p;
>>> + struct iio_dev *indio_dev = pf->indio_dev;
>>> + struct adc12138 *adc = iio_priv(indio_dev);
>>> + __be16 data[20] = { };
>>
>> why { } here?
>
> To initialize with zero and avoids exposing kernel stack to userspace
> through padding entries. I could use memset here.
>
>> why 20?
>
> When all scan elements are enabled, the sample data requires 40 bytes
> (2 bytes ADC data * 16 channels + 8 bytes timestamp).
>
> I'll add comments about these.
>
>>> + __be16 trash;
>>> + int ret;
>>> + int scan_index;
>>> + int i = 0;
>>> +
>>> + mutex_lock(&adc->lock);
>>> +
>>> + for_each_set_bit(scan_index, indio_dev->active_scan_mask,
>>> + indio_dev->masklength) {
>>> + const struct iio_chan_spec *scan_chan =
>>> + &indio_dev->channels[scan_index];
>>> +
>>> + reinit_completion(&adc->complete);
>>> +
>>> + ret = adc12138_start_and_read_conv(adc, scan_chan,
>>> + i ? &data[i - 1] : &trash);
>>> + if (ret) {
>>> + dev_warn(&adc->spi->dev,
>>> + "failed to start conversion\n");
>>> + goto out;
>>> + }
>>> +
>>> + ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
>>> + if (ret) {
>>> + dev_warn(&adc->spi->dev, "wait eoc timeout\n");
>>> + goto out;
>>> + }
>>> +
>>> + i++;
>>> + }
>>> +
>>> + if (i) {
>>> + ret = adc12138_read_conv_data(adc, &data[i - 1]);
>>> + if (ret) {
>>> + dev_warn(&adc->spi->dev,
>>> + "failed to get conversion data\n");
>>> + goto out;
>>> + }
>>> + }
>>> +
>>> + iio_push_to_buffers_with_timestamp(indio_dev, data, iio_get_time_ns());
>>> +out:
>>> + mutex_unlock(&adc->lock);
>>> +
>>> + iio_trigger_notify_done(indio_dev->trig);
>>> +
>>> + return IRQ_HANDLED;
>>> +}
> --
> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] iio: adc: add ADC12130/ADC12132/ADC12138 ADC driver
@ 2016-07-20 15:05 ` Jonathan Cameron
0 siblings, 0 replies; 10+ messages in thread
From: Jonathan Cameron @ 2016-07-20 15:05 UTC (permalink / raw)
To: Akinobu Mita, Peter Meerwald-Stadler
Cc: linux-iio, open list:OPEN FIRMWARE AND...,
Hartmut Knaack, Lars-Peter Clausen
On 19/07/16 17:24, Akinobu Mita wrote:
> 2016-07-19 7:02 GMT+09:00 Peter Meerwald-Stadler <pmeerw@pmeerw.net>:
>>
>>> This adds Texas Instruments' ADC12130/ADC12132/ADC12138 12-bit plus
>>> sign ADC driver. I have tested with the ADC12138. The ADC12130 and
>>> ADC12132 are not tested but these are similar to ADC12138 except that
>>> the mode programming instruction is a bit different.
>>
>> minor comments below
>>
>>> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
>>> Cc: Jonathan Cameron <jic23@kernel.org>
>>> Cc: Hartmut Knaack <knaack.h@gmx.de>
>>> Cc: Lars-Peter Clausen <lars@metafoo.de>
>>> Cc: Peter Meerwald <pmeerw@pmeerw.net>
>>> ---
>>> .../devicetree/bindings/iio/adc/ti-adc12138.txt | 32 ++
>>> drivers/iio/adc/Kconfig | 12 +
>>> drivers/iio/adc/Makefile | 1 +
>>> drivers/iio/adc/ti-adc12138.c | 541 +++++++++++++++++++++
>>> 4 files changed, 586 insertions(+)
>>> create mode 100644 Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
>>> create mode 100644 drivers/iio/adc/ti-adc12138.c
>>>
>>> diff --git a/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
>>> new file mode 100644
>>> index 0000000..3a11d2a
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/iio/adc/ti-adc12138.txt
>>> @@ -0,0 +1,32 @@
>>> +* Texas Instruments' ADC12130/ADC12132/ADC12138
>>> +
>>> +Required properties:
>>> + - compatible: Should be one of
>>> + * "ti,adc12130"
>>> + * "ti,adc12132"
>>> + * "ti,adc12138"
>>> + - reg: SPI chip select number for the device
>>> + - interrupts: Should contain interrupt for EOC (end of conversion)
>>> + - clocks: phandle to conversion clock input
>>> + - spi-max-frequency: Definision as per
>>> + Documentation/devicetree/bindings/spi/spi-bus.txt
>>> + - vref-p-supply: The regulator supply for positive analog voltage reference
>>> +
>>> +Optional properties:
>>> + - vref-n-supply: The regulator supply for negative analog voltage reference
>>> + If not specified, this is assumed to be analog ground.
>>> + - acquisition-time: The number of conversion clock periods for the S/H's
>>> + acquisition time. Should be one of 6, 10, 18, 34. If not specified,
>>> + default value of 10 is used.
>>> +
>>> +Example:
>>> +adc@0 {
>>> + compatible = "ti,adc12138";
>>> + reg = <0>;
>>> + interrupts = <28 IRQ_TYPE_EDGE_RISING>;
>>> + interrupt-parent = <&gpio1>;
>>> + clocks = <&cclk>;
>>> + vref-p-supply = <&ldo4_reg>;
>>> + spi-max-frequency = <5000000>;
>>> + acquisition-time = <6>;
>>> +};
>>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>>> index fa0ff29..0783291 100644
>>> --- a/drivers/iio/adc/Kconfig
>>> +++ b/drivers/iio/adc/Kconfig
>>> @@ -414,6 +414,18 @@ config TI_ADC0832
>>> This driver can also be built as a module. If so, the module will be
>>> called ti-adc0832.
>>>
>>> +config TI_ADC12138
>>> + tristate "Texas Instruments ADC12130/ADC12132/ADC12138"
>>> + depends on SPI
>>> + select IIO_BUFFER
>>> + select IIO_TRIGGERED_BUFFER
>>> + help
>>> + If you say yes here you get support for Texas Instruments ADC12130,
>>> + ADC12132and ADC12138 chips.
>>
>> space before 'and' missing
>
> Ugh.
>
>>> +
>>> + This driver can also be built as a module. If so, the module will be
>>> + called ti-adc12138.
>>> +
>>> config TI_ADC128S052
>>> tristate "Texas Instruments ADC128S052/ADC122S021/ADC124S021"
>>> depends on SPI
>>> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
>>> index 599714b..3ae4ae3 100644
>>> --- a/drivers/iio/adc/Makefile
>>> +++ b/drivers/iio/adc/Makefile
>>> @@ -40,6 +40,7 @@ obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
>>> obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
>>> obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
>>> obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
>>> +obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o
>>> obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
>>> obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
>>> obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
>>> diff --git a/drivers/iio/adc/ti-adc12138.c b/drivers/iio/adc/ti-adc12138.c
>>> new file mode 100644
>>> index 0000000..e7bd986
>>> --- /dev/null
>>> +++ b/drivers/iio/adc/ti-adc12138.c
>>> @@ -0,0 +1,541 @@
>>> +/*
>>> + * ADC12130/ADC12132/ADC12138 12-bit plus sign ADC driver
>>> + *
>>> + * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>
>>> + *
>>> + * This file is subject to the terms and conditions of version 2 of
>>> + * the GNU General Public License. See the file COPYING in the main
>>> + * directory of this archive for more details.
>>> + *
>>> + * Datasheet: http://www.ti.com/lit/ds/symlink/adc12138.pdf
>>> + */
>>> +
>>> +#include <linux/module.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/completion.h>
>>> +#include <linux/clk.h>
>>> +#include <linux/spi/spi.h>
>>> +#include <linux/iio/iio.h>
>>> +#include <linux/iio/buffer.h>
>>> +#include <linux/iio/trigger.h>
>>> +#include <linux/iio/triggered_buffer.h>
>>> +#include <linux/iio/trigger_consumer.h>
>>> +#include <linux/regulator/consumer.h>
>>> +
>>> +#define ADC12138_MODE_AUTO_CAL 0x08
>>> +#define ADC12138_MODE_READ_STATUS 0x0c
>>> +#define ADC12138_MODE_ACQUISITION_TIME_6 0x0e
>>> +#define ADC12138_MODE_ACQUISITION_TIME_10 0x4e
>>> +#define ADC12138_MODE_ACQUISITION_TIME_18 0x8e
>>> +#define ADC12138_MODE_ACQUISITION_TIME_34 0xce
>>> +
>>> +#define ADC12138_STATUS_CAL BIT(6)
>>> +
>>> +enum {
>>> + adc12130,
>>> + adc12132,
>>> + adc12138,
>>> +};
>>> +
>>> +struct adc12138 {
>>> + struct spi_device *spi;
>>> + unsigned int id;
>>> + /* conversion clock */
>>> + struct clk *cclk;
>>> + /* positive analog voltage reference */
>>> + struct regulator *vref_p;
>>> + /* negative analog voltage reference */
>>> + struct regulator *vref_n;
>>> + struct mutex lock;
>>> + struct completion complete;
>>> + unsigned int acquisition_time;
>>
>> unit? ms? µs?
>
> This is specified by the number of conversion clock (cclk) periods.
> I'll add a comment about it.
>
>>> +
>>> + u8 tx_buf[2] ____cacheline_aligned;
>>> + u8 rx_buf[2];
>>> +};
>>> +
>>> +#define ADC12138_VOLTAGE_CHANNEL(chan) \
>>> + { \
>>> + .type = IIO_VOLTAGE, \
>>> + .indexed = 1, \
>>> + .channel = chan, \
>>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>>> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
>>> + | BIT(IIO_CHAN_INFO_OFFSET), \
>>> + .scan_index = chan, \
>>> + .scan_type = { \
>>> + .sign = 's', \
>>> + .realbits = 13, \
>>> + .storagebits = 16, \
>>> + .shift = 3, \
>>> + .endianness = IIO_BE, \
>>> + }, \
>>> + }
>>> +
>>> +#define ADC12138_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si_offset) \
>>> + { \
>>> + .type = IIO_VOLTAGE, \
>>> + .indexed = 1, \
>>> + .channel = (chan1), \
>>> + .channel2 = (chan2), \
>>> + .differential = 1, \
>>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>>> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
>>> + | BIT(IIO_CHAN_INFO_OFFSET), \
>>> + .scan_index = (chan1) + (si_offset), \
>>> + .scan_type = { \
>>> + .sign = 's', \
>>> + .realbits = 13, \
>>> + .storagebits = 16, \
>>> + .shift = 3, \
>>> + .endianness = IIO_BE, \
>>> + }, \
>>> + }
>>> +
>>> +static const struct iio_chan_spec adc12132_channels[] = {
>>> + ADC12138_VOLTAGE_CHANNEL(0),
>>> + ADC12138_VOLTAGE_CHANNEL(1),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 2),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 2),
>>> + IIO_CHAN_SOFT_TIMESTAMP(4),
>>> +};
>>> +
>>> +static const struct iio_chan_spec adc12138_channels[] = {
>>> + ADC12138_VOLTAGE_CHANNEL(0),
>>> + ADC12138_VOLTAGE_CHANNEL(1),
>>> + ADC12138_VOLTAGE_CHANNEL(2),
>>> + ADC12138_VOLTAGE_CHANNEL(3),
>>> + ADC12138_VOLTAGE_CHANNEL(4),
>>> + ADC12138_VOLTAGE_CHANNEL(5),
>>> + ADC12138_VOLTAGE_CHANNEL(6),
>>> + ADC12138_VOLTAGE_CHANNEL(7),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(2, 3, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(3, 2, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(4, 5, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(5, 4, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(6, 7, 8),
>>> + ADC12138_VOLTAGE_CHANNEL_DIFF(7, 6, 8),
>>> + IIO_CHAN_SOFT_TIMESTAMP(16),
>>> +};
>>> +
>>> +static int adc12138_mode_programming(struct adc12138 *adc, u8 mode,
>>> + void *rx_buf, int len)
>>> +{
>>> + struct spi_transfer xfer = {
>>> + .tx_buf = adc->tx_buf,
>>> + .rx_buf = adc->rx_buf,
>>> + .len = len,
>>> + };
>>> + int ret;
>>> +
>>> + /* Skip disused bits for ADC12130 and ADC12132 */
>>
>> probably 'unused' instead of 'disused'
>
> OK.
>
>>> + if (adc->id != adc12138)
>>> + mode = (mode & 0xc0) | ((mode & 0x0f) << 2);
>>> +
>>> + adc->tx_buf[0] = mode;
>>> +
>>> + ret = spi_sync_transfer(adc->spi, &xfer, 1);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + memcpy(rx_buf, adc->rx_buf, len);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int adc12138_read_status(struct adc12138 *adc)
>>> +{
>>> + u8 rx_buf[2];
>>> + int ret;
>>> +
>>> + ret = adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
>>> + rx_buf, 2);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + return (rx_buf[0] << 1) | (rx_buf[1] >> 7);
>>> +}
>>> +
>>> +static int __adc12138_start_conv(struct adc12138 *adc,
>>> + struct iio_chan_spec const *channel,
>>> + void *data, int len)
>>> +
>>> +{
>>> + const u8 ch_to_mux[] = { 0, 4, 1, 5, 2, 6, 3, 7 };
>>> + u8 mode = (ch_to_mux[channel->channel] << 4) |
>>> + (channel->differential ? 0 : 0x80);
>>> +
>>> + return adc12138_mode_programming(adc, mode, data, len);
>>> +}
>>> +
>>> +static int adc12138_start_conv(struct adc12138 *adc,
>>> + struct iio_chan_spec const *channel)
>>> +{
>>> + u8 trash;
>>> +
>>> + return __adc12138_start_conv(adc, channel, &trash, 1);
>>> +}
>>> +
>>> +static int adc12138_start_and_read_conv(struct adc12138 *adc,
>>> + struct iio_chan_spec const *channel,
>>> + __be16 *data)
>>> +{
>>> + return __adc12138_start_conv(adc, channel, data, 2);
>>> +}
>>> +
>>> +static int adc12138_read_conv_data(struct adc12138 *adc, __be16 *value)
>>> +{
>>> + /* Issue a read status instruction and read previous conversion data */
>>> + return adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
>>> + value, sizeof(*value));
>>> +}
>>> +
>>> +static int adc12138_wait_eoc(struct adc12138 *adc, unsigned long timeout)
>>> +{
>>> + if (!wait_for_completion_timeout(&adc->complete, timeout))
>>> + return -ETIMEDOUT;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int adc12138_adc_conversion(struct adc12138 *adc,
>>> + struct iio_chan_spec const *channel,
>>> + __be16 *value)
>>> +{
>>> + int ret;
>>> +
>>> + reinit_completion(&adc->complete);
>>> +
>>> + ret = adc12138_start_conv(adc, channel);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
>>> + if (ret)
>>> + return ret;
>>> +
>>> + return adc12138_read_conv_data(adc, value);
>>> +}
>>> +
>>> +static int adc12138_read_raw(struct iio_dev *iio,
>>> + struct iio_chan_spec const *channel, int *value,
>>> + int *shift, long mask)
>>> +{
>>> + struct adc12138 *adc = iio_priv(iio);
>>> + int ret;
>>> + __be16 data;
>>> +
>>> + switch (mask) {
>>> + case IIO_CHAN_INFO_RAW:
>>
>> what if buffered reads have been set up? probably use
>> iio_device_claim_direct_mode()
>
> Maybe it is safe because the ADC data is always requested and retrieved
> while holding adc12138.lock from adc12138_read_raw() and
> adc12138_trigger_handler(). Is it better to restrict direct mode and
> return -EBUSY while buffer mode is enabled?
>
> (BTW, I realized that I can use iio_dev->mlock instead of adc12138.lock)
Don't use it for anything other than state change locking. It has that
well focused task within the subsystem - we are trying to clear out other
uses entirely as there have been more than a few bugs around this.
Much better to have a separate lock for protecting resources controlled
directly by the driver itself.
>
>>> + mutex_lock(&adc->lock);
>>> + ret = adc12138_adc_conversion(adc, channel, &data);
>>> + mutex_unlock(&adc->lock);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + *value = sign_extend32(be16_to_cpu(data) >> 3, 12);
>>> +
>>> + return IIO_VAL_INT;
>>> + case IIO_CHAN_INFO_SCALE:
>>> + ret = regulator_get_voltage(adc->vref_p);
>>> + if (ret < 0)
>>> + return ret;
>>> + *value = ret;
>>> +
>>> + if (!IS_ERR(adc->vref_n)) {
>>> + ret = regulator_get_voltage(adc->vref_n);
>>> + if (ret < 0)
>>> + return ret;
>>> + *value -= ret;
>>> + }
>>> +
>>> + /* convert regulator output voltage to mV */
>>> + *value /= 1000;
>>> + *shift = channel->scan_type.realbits - 1;
>>> +
>>> + return IIO_VAL_FRACTIONAL_LOG2;
>>> + case IIO_CHAN_INFO_OFFSET:
>>> + if (!IS_ERR(adc->vref_n)) {
>>> + *value = regulator_get_voltage(adc->vref_n);
>>> + if (*value < 0)
>>> + return *value;
>>> + } else {
>>> + *value = 0;
>>> + }
>>> +
>>> + /* convert regulator output voltage to mV */
>>> + *value /= 1000;
>>> +
>>> + return IIO_VAL_INT;
>>> + }
>>> +
>>> + return -EINVAL;
>>> +}
>>> +
>>> +static const struct iio_info adc12138_info = {
>>> + .read_raw = adc12138_read_raw,
>>> + .driver_module = THIS_MODULE,
>>> +};
>>> +
>>> +static int adc12138_init(struct adc12138 *adc)
>>> +{
>>> + int ret;
>>> + int status;
>>> + u8 mode;
>>> + u8 trash;
>>> +
>>> + reinit_completion(&adc->complete);
>>> +
>>> + ret = adc12138_mode_programming(adc, ADC12138_MODE_AUTO_CAL, &trash, 1);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + /* data output at this time has no significance */
>>> + status = adc12138_read_status(adc);
>>> + if (status < 0)
>>> + return status;
>>> +
>>> + adc12138_wait_eoc(adc, msecs_to_jiffies(100));
>>> +
>>> + status = adc12138_read_status(adc);
>>> + if (status & ADC12138_STATUS_CAL) {
>>> + dev_warn(&adc->spi->dev,
>>> + "Auto Cal sequence is still in progress: %#x\n",
>>> + status);
>>> + return -EIO;
>>> + }
>>> +
>>> + switch (adc->acquisition_time) {
>>> + case 6:
>>> + mode = ADC12138_MODE_ACQUISITION_TIME_6;
>>> + break;
>>> + case 10:
>>> + mode = ADC12138_MODE_ACQUISITION_TIME_10;
>>> + break;
>>> + case 18:
>>> + mode = ADC12138_MODE_ACQUISITION_TIME_18;
>>> + break;
>>> + case 34:
>>> + mode = ADC12138_MODE_ACQUISITION_TIME_34;
>>> + break;
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> +
>>> + return adc12138_mode_programming(adc, mode, &trash, 1);
>>> +}
>>> +
>>> +static irqreturn_t adc12138_trigger_handler(int irq, void *p)
>>> +{
>>> + struct iio_poll_func *pf = p;
>>> + struct iio_dev *indio_dev = pf->indio_dev;
>>> + struct adc12138 *adc = iio_priv(indio_dev);
>>> + __be16 data[20] = { };
>>
>> why { } here?
>
> To initialize with zero and avoids exposing kernel stack to userspace
> through padding entries. I could use memset here.
>
>> why 20?
>
> When all scan elements are enabled, the sample data requires 40 bytes
> (2 bytes ADC data * 16 channels + 8 bytes timestamp).
>
> I'll add comments about these.
>
>>> + __be16 trash;
>>> + int ret;
>>> + int scan_index;
>>> + int i = 0;
>>> +
>>> + mutex_lock(&adc->lock);
>>> +
>>> + for_each_set_bit(scan_index, indio_dev->active_scan_mask,
>>> + indio_dev->masklength) {
>>> + const struct iio_chan_spec *scan_chan =
>>> + &indio_dev->channels[scan_index];
>>> +
>>> + reinit_completion(&adc->complete);
>>> +
>>> + ret = adc12138_start_and_read_conv(adc, scan_chan,
>>> + i ? &data[i - 1] : &trash);
>>> + if (ret) {
>>> + dev_warn(&adc->spi->dev,
>>> + "failed to start conversion\n");
>>> + goto out;
>>> + }
>>> +
>>> + ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
>>> + if (ret) {
>>> + dev_warn(&adc->spi->dev, "wait eoc timeout\n");
>>> + goto out;
>>> + }
>>> +
>>> + i++;
>>> + }
>>> +
>>> + if (i) {
>>> + ret = adc12138_read_conv_data(adc, &data[i - 1]);
>>> + if (ret) {
>>> + dev_warn(&adc->spi->dev,
>>> + "failed to get conversion data\n");
>>> + goto out;
>>> + }
>>> + }
>>> +
>>> + iio_push_to_buffers_with_timestamp(indio_dev, data, iio_get_time_ns());
>>> +out:
>>> + mutex_unlock(&adc->lock);
>>> +
>>> + iio_trigger_notify_done(indio_dev->trig);
>>> +
>>> + return IRQ_HANDLED;
>>> +}
> --
> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2016-07-20 15:05 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-07-18 15:00 [PATCH] iio: adc: add ADC12130/ADC12132/ADC12138 ADC driver Akinobu Mita
2016-07-18 15:00 ` Akinobu Mita
[not found] ` <1468854029-22153-1-git-send-email-akinobu.mita-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2016-07-18 22:02 ` Peter Meerwald-Stadler
2016-07-18 22:02 ` Peter Meerwald-Stadler
[not found] ` <alpine.DEB.2.02.1607182348340.25263-jW+XmwGofnusTnJN9+BGXg@public.gmane.org>
2016-07-19 16:24 ` Akinobu Mita
2016-07-19 16:24 ` Akinobu Mita
[not found] ` <CAC5umyjV0cUG3ovfqDy8nyDZYz_yYTwxnp7ti1T_xvz=FjWSNQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-07-20 15:05 ` Jonathan Cameron
2016-07-20 15:05 ` Jonathan Cameron
2016-07-20 1:11 ` Rob Herring
2016-07-20 1:11 ` Rob Herring
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