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-rw-r--r--drivers/iio/adc/ti-adc081c.c245
1 files changed, 245 insertions, 0 deletions
diff --git a/drivers/iio/adc/ti-adc081c.c b/drivers/iio/adc/ti-adc081c.c
new file mode 100644
index 0000000000..50c450e7a5
--- /dev/null
+++ b/drivers/iio/adc/ti-adc081c.c
@@ -0,0 +1,245 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TI ADC081C/ADC101C/ADC121C 8/10/12-bit ADC driver
+ *
+ * Copyright (C) 2012 Avionic Design GmbH
+ * Copyright (C) 2016 Intel
+ *
+ * Datasheets:
+ * https://www.ti.com/lit/ds/symlink/adc081c021.pdf
+ * https://www.ti.com/lit/ds/symlink/adc101c021.pdf
+ * https://www.ti.com/lit/ds/symlink/adc121c021.pdf
+ *
+ * The devices have a very similar interface and differ mostly in the number of
+ * bits handled. For the 8-bit and 10-bit models the least-significant 4 or 2
+ * bits of value registers are reserved.
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/regulator/consumer.h>
+
+struct adc081c {
+ struct i2c_client *i2c;
+ struct regulator *ref;
+
+ /* 8, 10 or 12 */
+ int bits;
+
+ /* Ensure natural alignment of buffer elements */
+ struct {
+ u16 channel;
+ s64 ts __aligned(8);
+ } scan;
+};
+
+#define REG_CONV_RES 0x00
+
+static int adc081c_read_raw(struct iio_dev *iio,
+ struct iio_chan_spec const *channel, int *value,
+ int *shift, long mask)
+{
+ struct adc081c *adc = iio_priv(iio);
+ int err;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);
+ if (err < 0)
+ return err;
+
+ *value = (err & 0xFFF) >> (12 - adc->bits);
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ err = regulator_get_voltage(adc->ref);
+ if (err < 0)
+ return err;
+
+ *value = err / 1000;
+ *shift = adc->bits;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ default:
+ break;
+ }
+
+ return -EINVAL;
+}
+
+#define ADCxx1C_CHAN(_bits) { \
+ .type = IIO_VOLTAGE, \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = (_bits), \
+ .storagebits = 16, \
+ .shift = 12 - (_bits), \
+ .endianness = IIO_CPU, \
+ }, \
+}
+
+#define DEFINE_ADCxx1C_CHANNELS(_name, _bits) \
+ static const struct iio_chan_spec _name ## _channels[] = { \
+ ADCxx1C_CHAN((_bits)), \
+ IIO_CHAN_SOFT_TIMESTAMP(1), \
+ }; \
+
+#define ADC081C_NUM_CHANNELS 2
+
+struct adcxx1c_model {
+ const struct iio_chan_spec* channels;
+ int bits;
+};
+
+#define ADCxx1C_MODEL(_name, _bits) \
+ { \
+ .channels = _name ## _channels, \
+ .bits = (_bits), \
+ }
+
+DEFINE_ADCxx1C_CHANNELS(adc081c, 8);
+DEFINE_ADCxx1C_CHANNELS(adc101c, 10);
+DEFINE_ADCxx1C_CHANNELS(adc121c, 12);
+
+/* Model ids are indexes in _models array */
+enum adcxx1c_model_id {
+ ADC081C = 0,
+ ADC101C = 1,
+ ADC121C = 2,
+};
+
+static struct adcxx1c_model adcxx1c_models[] = {
+ ADCxx1C_MODEL(adc081c, 8),
+ ADCxx1C_MODEL(adc101c, 10),
+ ADCxx1C_MODEL(adc121c, 12),
+};
+
+static const struct iio_info adc081c_info = {
+ .read_raw = adc081c_read_raw,
+};
+
+static irqreturn_t adc081c_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct adc081c *data = iio_priv(indio_dev);
+ int ret;
+
+ ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES);
+ if (ret < 0)
+ goto out;
+ data->scan.channel = ret;
+ iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
+ iio_get_time_ns(indio_dev));
+out:
+ iio_trigger_notify_done(indio_dev->trig);
+ return IRQ_HANDLED;
+}
+
+static void adc081c_reg_disable(void *reg)
+{
+ regulator_disable(reg);
+}
+
+static int adc081c_probe(struct i2c_client *client)
+{
+ const struct i2c_device_id *id = i2c_client_get_device_id(client);
+ struct iio_dev *iio;
+ struct adc081c *adc;
+ const struct adcxx1c_model *model;
+ int err;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
+ return -EOPNOTSUPP;
+
+ if (dev_fwnode(&client->dev))
+ model = device_get_match_data(&client->dev);
+ else
+ model = &adcxx1c_models[id->driver_data];
+
+ iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));
+ if (!iio)
+ return -ENOMEM;
+
+ adc = iio_priv(iio);
+ adc->i2c = client;
+ adc->bits = model->bits;
+
+ adc->ref = devm_regulator_get(&client->dev, "vref");
+ if (IS_ERR(adc->ref))
+ return PTR_ERR(adc->ref);
+
+ err = regulator_enable(adc->ref);
+ if (err < 0)
+ return err;
+
+ err = devm_add_action_or_reset(&client->dev, adc081c_reg_disable,
+ adc->ref);
+ if (err)
+ return err;
+
+ iio->name = dev_name(&client->dev);
+ iio->modes = INDIO_DIRECT_MODE;
+ iio->info = &adc081c_info;
+
+ iio->channels = model->channels;
+ iio->num_channels = ADC081C_NUM_CHANNELS;
+
+ err = devm_iio_triggered_buffer_setup(&client->dev, iio, NULL,
+ adc081c_trigger_handler, NULL);
+ if (err < 0) {
+ dev_err(&client->dev, "iio triggered buffer setup failed\n");
+ return err;
+ }
+
+ return devm_iio_device_register(&client->dev, iio);
+}
+
+static const struct i2c_device_id adc081c_id[] = {
+ { "adc081c", ADC081C },
+ { "adc101c", ADC101C },
+ { "adc121c", ADC121C },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, adc081c_id);
+
+static const struct acpi_device_id adc081c_acpi_match[] = {
+ /* Used on some AAEON boards */
+ { "ADC081C", (kernel_ulong_t)&adcxx1c_models[ADC081C] },
+ { }
+};
+MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match);
+
+static const struct of_device_id adc081c_of_match[] = {
+ { .compatible = "ti,adc081c", .data = &adcxx1c_models[ADC081C] },
+ { .compatible = "ti,adc101c", .data = &adcxx1c_models[ADC101C] },
+ { .compatible = "ti,adc121c", .data = &adcxx1c_models[ADC121C] },
+ { }
+};
+MODULE_DEVICE_TABLE(of, adc081c_of_match);
+
+static struct i2c_driver adc081c_driver = {
+ .driver = {
+ .name = "adc081c",
+ .of_match_table = adc081c_of_match,
+ .acpi_match_table = adc081c_acpi_match,
+ },
+ .probe = adc081c_probe,
+ .id_table = adc081c_id,
+};
+module_i2c_driver(adc081c_driver);
+
+MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
+MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver");
+MODULE_LICENSE("GPL v2");