Basic driver for Texas Instruments TLA202x series ADCs. Input
channels are configurable from the device tree. Input scaling
is supported. Trigger buffer support is not yet implemented.
Signed-off-by: Ibtsam Ul-Haq <ibtsam.haq.0x01@xxxxxxxxx>
---
Changes in v3:
- Added locking when setting SCALE
- Removed deep-indented goto in read_raw
- Other minor points mentioned in v2 review
---
Changes in v2:
- changed commit message
- Added mutex to protect channel selection
- Removed redundant mutex around i2c transfers
- Removed PROCESSED channel output
- Added SCALE info
- Removed Continuous Mode since continuous read not supported
- Removed SAMP_FREQ info since continuous read not supported
---
---
drivers/iio/adc/Kconfig | 11 ++
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti-tla2024.c | 460 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 472 insertions(+)
create mode 100644 drivers/iio/adc/ti-tla2024.c
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 5762565..8c214c8 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -816,6 +816,17 @@ config TI_AM335X_ADC
To compile this driver as a module, choose M here: the module will be
called ti_am335x_adc.
+config TI_TLA2024
+ tristate "Texas Instruments TLA2024/TLA2022/TLA2021 ADC driver"
+ depends on OF
+ depends on I2C
+ help
+ Say yes here to build support for Texas Instruments TLA2024,
+ TLA2022 or TLA2021 I2C Analog to Digital Converters.
+
+ To compile this driver as a module, choose M here: the
+ module will be called ti-tla2024.
+
config TI_TLC4541
tristate "Texas Instruments TLC4541 ADC driver"
depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 9874e05..819f35b 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -75,6 +75,7 @@ obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o
obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
obj-$(CONFIG_TI_TLC4541) += ti-tlc4541.o
+obj-$(CONFIG_TI_TLA2024) += ti-tla2024.o
obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o
obj-$(CONFIG_TWL6030_GPADC) += twl6030-gpadc.o
obj-$(CONFIG_VF610_ADC) += vf610_adc.o
diff --git a/drivers/iio/adc/ti-tla2024.c b/drivers/iio/adc/ti-tla2024.c
new file mode 100644
index 0000000..f0eed4a
--- /dev/null
+++ b/drivers/iio/adc/ti-tla2024.c
@@ -0,0 +1,460 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Texas Instruments TLA2021/TLA2022/TLA2024 12-bit ADC driver
+ *
+ * Copyright (C) 2019 Koninklijke Philips N.V.
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#define TLA2024_DATA 0x00
+#define TLA2024_DATA_RES_MASK GENMASK(15, 4)
+#define TLA2024_DATA_RES_SHIFT 4
+
+#define TLA2024_CONF 0x01
+#define TLA2024_CONF_OS_MASK BIT(15)
+#define TLA2024_CONF_OS_SHIFT 15
+#define TLA2024_CONF_MUX_MASK GENMASK(14, 12)
+#define TLA2024_CONF_MUX_SHIFT 12
+#define TLA2024_CONF_PGA_MASK GENMASK(11, 9)
+#define TLA2024_CONF_PGA_SHIFT 9
+#define TLA2024_CONF_MODE_MASK BIT(8)
+#define TLA2024_CONF_MODE_SHIFT 8
+#define TLA2024_CONF_DR_MASK GENMASK(7, 5)
+#define TLA2024_CONF_DR_SHIFT 5
+
+#define TLA2024_CONV_RETRY 10
+
+struct tla202x_model {
+ unsigned int mux_available;
+ unsigned int pga_available;
+};
+
+struct tla2024 {
+ struct i2c_client *i2c;
+ struct tla202x_model *model;
+ struct mutex lock;
+ u8 used_mux_channels;
+};
+
+struct tla2024_channel {
+ int ainp;
+ int ainn;
+ const char *datasheet_name;
+ bool differential;
+};
+
+static const struct tla2024_channel tla2024_all_channels[] = {
+ {0, 1, "AIN0-AIN1", 1},
+ {0, 3, "AIN0-AIN3", 1},
+ {1, 3, "AIN1-AIN3", 1},
+ {2, 3, "AIN2-AIN3", 1},
+ {0, -1, "AIN0", 0},
+ {1, -1, "AIN1", 0},
+ {2, -1, "AIN2", 0},
+ {3, -1, "AIN3", 0},
+};
+
+static int tla2024_find_chan_idx(u32 ainp_in, u32 ainn_in, u16 *idx)
+{
+ u16 i;
+
+ for (i = 0; i < ARRAY_SIZE(tla2024_all_channels); i++) {
+ if ((tla2024_all_channels[i].ainp == ainp_in) &&
+ (tla2024_all_channels[i].ainn == ainn_in)) {
+ *idx = i;
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+#define TLA202x_MODEL(_mux, _pga) \
+ { \
+ .mux_available = (_mux), \
+ .pga_available = (_pga), \
+ }
+
+enum tla2024_model_id {
+ TLA2021 = 0,
+ TLA2022 = 1,
+ TLA2024 = 2,
+};
+
+static struct tla202x_model tla202x_models[] = {
+ [TLA2021] = TLA202x_MODEL(0, 0),
+ [TLA2022] = TLA202x_MODEL(0, 1),
+ [TLA2024] = TLA202x_MODEL(1, 1),
+};
+
+static const int tla2024_scale[] = { /* scale, int plus micro */
+ 3, 0, 2, 0, 1, 0, 0, 500000, 0, 250000, 0, 125000 };
+
+static int tla2024_get(struct tla2024 *priv, u8 addr, u16 mask,
+ u16 shift, u16 *val)
+{
+ int ret;
+ u16 data;
+
+ ret = i2c_smbus_read_word_swapped(priv->i2c, addr);
+ if (ret < 0)
+ return ret;
+
+ data = ret;
+ *val = (mask & data) >> shift;
+
+ return 0;
+}
+
+static int tla2024_set(struct tla2024 *priv, u8 addr, u16 mask,
+ u16 shift, u16 val)
+{
+ int ret;
+ u16 data;
+
+ ret = i2c_smbus_read_word_swapped(priv->i2c, addr);
+ if (ret < 0)
+ return ret;
+
+ data = ret;
+ data &= ~mask;
+ data |= mask & (val << shift);
+
+ ret = i2c_smbus_write_word_swapped(priv->i2c, addr, data);
+
+ return ret;
+}
+
+static int tla2024_read_avail(struct iio_dev *idev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long mask)
+{
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+
+ *length = ARRAY_SIZE(tla2024_scale);
+ *vals = tla2024_scale;
+
+ *type = IIO_VAL_INT_PLUS_MICRO;
+ return IIO_AVAIL_LIST;
+ }
+
+ return -EINVAL;
+}
+
+static int tla2024_of_find_chan(struct tla2024 *priv, struct device_node *ch)
+{
+ u16 chan_idx = 0;
+ u32 ainp, ainn;
+ int ret;
+
+ ret = of_property_read_u32_index(ch, "single-channel", 0, &ainp);
+ if (ret) {
+ ret = of_property_read_u32_index(ch,
+ "diff-channels", 0, &ainp);
+ if (ret)
+ return ret;
+
+ ret = of_property_read_u32_index(ch,
+ "diff-channels", 1, &ainn);
+ if (ret)
+ return ret;
+
+ } else {
+ ainn = UINT_MAX;
+ }
+
+ ret = tla2024_find_chan_idx(ainp, ainn, &chan_idx);
+ if (ret < 0)
+ return ret;
+
+ /* if model doesn"t have mux then only channel 0 is allowed */
+ if (!priv->model->mux_available && chan_idx)
+ return -EINVAL;
+
+ /* if already used */
+ if ((priv->used_mux_channels) & (1 << chan_idx))
+ return -EINVAL;
+
+ return chan_idx;
+}
+
+static int tla2024_init_chan(struct iio_dev *idev, struct device_node *node,
+ struct iio_chan_spec *chan)
+{
+ struct tla2024 *priv = iio_priv(idev);
+ u16 chan_idx;
+ int ret;
+
+ ret = tla2024_of_find_chan(priv, node);
+ if (ret < 0)
+ return ret;
+
+ chan_idx = ret;
+ priv->used_mux_channels |= BIT(chan_idx);
+ chan->type = IIO_VOLTAGE;
+ chan->channel = tla2024_all_channels[chan_idx].ainp;
+ chan->channel2 = tla2024_all_channels[chan_idx].ainn;
+ chan->differential = tla2024_all_channels[chan_idx].differential;
+ chan->datasheet_name = tla2024_all_channels[chan_idx].datasheet_name;
+ chan->indexed = 1;
+ chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+ chan->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE);
+ chan->info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SCALE);
+
+ return 0;
+}
+
+static int tla2024_wait(struct tla2024 *priv)
+{
+ int ret;
+ unsigned int retry = TLA2024_CONV_RETRY;
+ u16 status;
+
+ do {
+ if (!--retry)
+ return -EIO;
+ ret = tla2024_get(priv, TLA2024_CONF, TLA2024_CONF_OS_MASK,
+ TLA2024_CONF_OS_SHIFT, &status);
+ if (ret < 0)
+ return ret;
+ if (!status)
+ usleep_range(25, 1000);
+ } while (!status);
+
+ return ret;
+}
+
+static int tla2024_singleshot_conv(struct tla2024 *priv,
+ struct iio_chan_spec const *chan, int *val)
+{
+ int ret;
+ u32 ainp = chan->channel;
+ u32 ainn = chan->channel2;
+ u16 chan_id, data;
+ s16 tmp;
+
+ ret = tla2024_set(priv, TLA2024_CONF, TLA2024_CONF_MODE_MASK,
+ TLA2024_CONF_MODE_SHIFT, 1);
+ if (ret < 0)
+ return ret;
+
+ ret = tla2024_find_chan_idx(ainp, ainn, &chan_id);
+ if (ret < 0)
+ return ret;
+
+ ret = tla2024_set(priv, TLA2024_CONF, TLA2024_CONF_MUX_MASK,
+ TLA2024_CONF_MUX_SHIFT, chan_id);
+ if (ret < 0)
+ return ret;
+
+ ret = tla2024_set(priv, TLA2024_CONF, TLA2024_CONF_OS_MASK,
+ TLA2024_CONF_OS_SHIFT, 1);
+ if (ret < 0)
+ return ret;
+
+ ret = tla2024_wait(priv);
+ if (ret < 0)
+ return ret;
+
+ ret = tla2024_get(priv, TLA2024_DATA, TLA2024_DATA_RES_MASK,
+ TLA2024_DATA_RES_SHIFT, &data);
+ if (ret < 0)
+ return ret;
+
+ tmp = (s16)(data << TLA2024_DATA_RES_SHIFT);
+ *val = tmp >> TLA2024_DATA_RES_SHIFT;
+ return IIO_VAL_INT;
+}
+
+static int tla2024_set_scale(struct tla2024 *priv, int val, int val2)
+{
+ int i;
+
+ if (!(priv->model->pga_available))
+ return -EINVAL; /* scale can't be changed if no pga */
+
+ for (i = 0; i < ARRAY_SIZE(tla2024_scale); i = i + 2) {
+ if ((tla2024_scale[i] == val) &&
+ (tla2024_scale[i + 1] == val2))
+ break;
+ }
+
+ if (i == ARRAY_SIZE(tla2024_scale))
+ return -EINVAL;
+
+ return tla2024_set(priv, TLA2024_CONF, TLA2024_CONF_PGA_MASK,
+ TLA2024_CONF_PGA_SHIFT, i >> 1);
+}
+
+static int tla2024_get_scale(struct tla2024 *priv, int *val, int *val2)
+{
+ u16 data;
+ int ret;
+
+ if (!(priv->model->pga_available)) {
+ *val = 1; /* Scale always 1 mV when no PGA */
+ return IIO_VAL_INT;
+ }
+ ret = tla2024_get(priv, TLA2024_CONF, TLA2024_CONF_PGA_MASK,
+ TLA2024_CONF_PGA_SHIFT, &data);
+ if (ret < 0)
+ return ret;
+
+ /* gain for the 3bit pga values 6 and 7 is same as at 5 */
+ if (data >= (ARRAY_SIZE(tla2024_scale) >> 1))
+ data = (ARRAY_SIZE(tla2024_scale) >> 1) - 1;
+
+ *val = tla2024_scale[data << 1];
+ *val2 = tla2024_scale[(data << 1) + 1];
+ return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int tla2024_read_raw(struct iio_dev *idev,
+ struct iio_chan_spec const *channel, int *val,
+ int *val2, long mask)
+{
+ struct tla2024 *priv = iio_priv(idev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&priv->lock);
+ ret = tla2024_singleshot_conv(priv, channel, val);
+ mutex_unlock(&priv->lock);
+ return ret;
+
+ case IIO_CHAN_INFO_SCALE:
+ return tla2024_get_scale(priv, val, val2);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int tla2024_write_raw(struct iio_dev *idev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct tla2024 *priv = iio_priv(idev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ mutex_lock(&priv->lock);
+ ret = tla2024_set_scale(priv, val, val2);
+ mutex_unlock(&priv->lock);
+ return ret;
+ }
+
+ return -EINVAL;
+}
+
+static int tla2024_of_chan_init(struct iio_dev *idev)
+{
+ struct device_node *node = idev->dev.of_node;
+ struct device_node *child;
+ struct iio_chan_spec *channels;
+ int ret, i, num_channels;
+
+ num_channels = of_get_available_child_count(node);
+ if (!num_channels) {
+ dev_err(&idev->dev, "no channels configured\n");
+ return -ENODEV;
+ }
+
+ channels = devm_kcalloc(&idev->dev, num_channels,
+ sizeof(struct iio_chan_spec), GFP_KERNEL);
+ if (!channels)
+ return -ENOMEM;
+
+ i = 0;
+ for_each_available_child_of_node(node, child) {
+ ret = tla2024_init_chan(idev, child, &channels[i]);
+ if (ret) {
+ of_node_put(child);
+ return ret;
+ }
+ i++;
+ }
+
+ idev->channels = channels;
+ idev->num_channels = num_channels;
+
+ return 0;
+}
+
+static const struct iio_info tla2024_info = {
+ .read_raw = tla2024_read_raw,
+ .write_raw = tla2024_write_raw,
+ .read_avail = tla2024_read_avail,
+};
+
+static int tla2024_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct iio_dev *iio;
+ struct tla2024 *priv;
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_WORD_DATA))
+ return -EOPNOTSUPP;
+
+ iio = devm_iio_device_alloc(&client->dev, sizeof(*priv));
+ if (!iio)
+ return -ENOMEM;
+
+ priv = iio_priv(iio);
+ priv->i2c = client;
+ priv->model = &tla202x_models[id->driver_data];
+ mutex_init(&priv->lock);
+
+ iio->dev.parent = &client->dev;
+ iio->dev.of_node = client->dev.of_node;
+ iio->name = client->name;
+ iio->modes = INDIO_DIRECT_MODE;
+ iio->info = &tla2024_info;
+
+ ret = tla2024_of_chan_init(iio);
+ if (ret < 0)
+ return ret;
+
+ return devm_iio_device_register(&client->dev, iio);
+}
+
+static const struct i2c_device_id tla2024_id[] = {
+ { "tla2024", TLA2024 },
+ { "tla2022", TLA2022 },
+ { "tla2021", TLA2021 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, tla2024_id);
+
+static const struct of_device_id tla2024_of_match[] = {
+ { .compatible = "ti,tla2024" },
+ { .compatible = "ti,tla2022" },
+ { .compatible = "ti,tla2021" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, tla2024_of_match);
+
+static struct i2c_driver tla2024_driver = {
+ .driver = {
+ .name = "tla2024",
+ .of_match_table = of_match_ptr(tla2024_of_match),
+ },
+ .probe = tla2024_probe,
+ .id_table = tla2024_id,
+};
+module_i2c_driver(tla2024_driver);
+
+MODULE_AUTHOR("Ibtsam Haq <ibtsam.haq@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Texas Instruments TLA2021/TLA2022/TLA2024 ADC driver");
+MODULE_LICENSE("GPL v2");
--
2.7.4
