| Message ID | 1553608583-29006-1-git-send-email-ibtsam.haq.0x01@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3,1/2] iio: Add driver for TLA202x ADCs | expand |
On Tue, 26 Mar 2019 14:56:19 +0100 Ibtsam Ul-Haq <ibtsam.haq.0x01@gmail.com> wrote: > 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@gmail.com> Down to the nitpicks on this version so should be good for a v4. Also probably some minor tweaks needed due to the discussion around the dt binding. Jonathan > --- > 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; return 0; It can't be anything else and get here (I think!) > +} > + > +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; Are these local variables worthwhile as value only used in one place? > + 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]; When doing indexes like this it's probably more readable to just use * 2 rather than the shift. The compiler should figure it out anyway. Also / 2 is fine when can be evaluated at compile time as above. > + 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; > +} > + The ordering of functions in here seems a little strange. I would bring this together with the individual channel init code above and not have it between the callbacks and the definition of the struct iio_info below. > +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@philips.com>"); > +MODULE_DESCRIPTION("Texas Instruments TLA2021/TLA2022/TLA2024 ADC driver"); > +MODULE_LICENSE("GPL v2");
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@philips.com>"); +MODULE_DESCRIPTION("Texas Instruments TLA2021/TLA2022/TLA2024 ADC driver"); +MODULE_LICENSE("GPL v2");
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@gmail.com> --- 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