Re: [PATCH v4] iio: adc: Add TI ADS1015 ADC driver support
From: Daniel Baluta
Date: Fri Feb 05 2016 - 14:32:40 EST
On Fri, Feb 5, 2016 at 7:25 PM, Michael Welling <mwelling@xxxxxxxx> wrote:
> On Fri, Feb 05, 2016 at 03:17:18PM +0200, Daniel Baluta wrote:
>> The driver has sysfs readings with runtime PM support for power saving.
>> It also offers buffer support that can be used together with IIO software
>> triggers.
>>
>> Datasheet can be found here:
>> http://www.ti.com.cn/cn/lit/ds/symlink/ads1015.pdf
>>
>> Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
>> ---
>> Changes since v3:
>> * fixed type connectd -> connected
>> * move mutex outside of switch in read_raw to be consistent
>> with write_raw
>>
>> Changes since v2:
>> * push locking out of the switch in write_raw
>> * fix buf allocation in triggered buffer's handler
>>
>> Changes since v1:
>> * addressed concerns about replacing the ads1015 hwmon driver
>> * For the moment the IIO driver is compatible with hwmon
>> driver (dt bindings) the only thing left is to also add
>> support for ads1115.
>> * DT bindings are described in Documentation/devicetree/
>> bindings/hwmon/ads1015.txt. If needed will copy this file
>> in a later patch to the IIO corresponding location.
>> * addressed comments from Jonathan
>> * added proper locking
>> * added timestamp channel
>> * removed magic constants
>> * added some new lines to increase readability
>> * used regmap_get_device instead of keeping a copy of
>> i2c_client pointer.
>> * used non-devm function to correct the cleanup order
>>
>> drivers/iio/adc/Kconfig | 13 +
>> drivers/iio/adc/Makefile | 1 +
>> drivers/iio/adc/ti-ads1015.c | 610 +++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 624 insertions(+)
>> create mode 100644 drivers/iio/adc/ti-ads1015.c
>>
>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>> index 60673b4..fad7e6a 100644
>> --- a/drivers/iio/adc/Kconfig
>> +++ b/drivers/iio/adc/Kconfig
>> @@ -370,6 +370,19 @@ config TI_ADC128S052
>> This driver can also be built as a module. If so, the module will be
>> called ti-adc128s052.
>>
>> +config TI_ADS1015
>> + tristate "Texas Instruments ADS1015 ADC"
>> + depends on I2C && !SENSORS_ADS1015
>> + select REGMAP_I2C
>> + select IIO_BUFFER
>> + select IIO_TRIGGERED_BUFFER
>> + help
>> + If you say yes here you get support for Texas Instruments ADS1015
>> + ADC chip.
>> +
>> + This driver can also be built as a module. If so, the module will be
>> + called ti-ads1015.
>> +
>> config TI_ADS8688
>> tristate "Texas Instruments ADS8688"
>> depends on SPI && OF
>> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
>> index fb57e12..2ff70a3 100644
>> --- a/drivers/iio/adc/Makefile
>> +++ b/drivers/iio/adc/Makefile
>> @@ -36,6 +36,7 @@ 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_ADC128S052) += ti-adc128s052.o
>> +obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
>> obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
>> obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
>> obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o
>> diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
>> new file mode 100644
>> index 0000000..596335f
>> --- /dev/null
>> +++ b/drivers/iio/adc/ti-ads1015.c
>> @@ -0,0 +1,610 @@
>> +/*
>> + * ADS1015 - Texas Instruments Analog-to-Digital Converter
>> + *
>> + * Copyright (c) 2016, Intel Corporation.
>> + *
>> + * 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.
>> + *
>> + * IIO driver for ADS1015 ADC 7-bit I2C slave address:
>> + * * 0x48 - ADDR connected to Ground
>> + * * 0x49 - ADDR connected to Vdd
>> + * * 0x4A - ADDR connected to SDA
>> + * * 0x4B - ADDR connected to SCL
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/init.h>
>> +#include <linux/i2c.h>
>> +#include <linux/regmap.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/mutex.h>
>> +#include <linux/delay.h>
>> +
>> +#include <linux/i2c/ads1015.h>
>> +
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/types.h>
>> +#include <linux/iio/sysfs.h>
>> +#include <linux/iio/buffer.h>
>> +#include <linux/iio/triggered_buffer.h>
>> +#include <linux/iio/trigger_consumer.h>
>> +
>> +#define ADS1015_DRV_NAME "ads1015"
>> +
>> +#define ADS1015_CONV_REG 0x00
>> +#define ADS1015_CFG_REG 0x01
>> +
>> +#define ADS1015_CFG_DR_SHIFT 5
>> +#define ADS1015_CFG_MOD_SHIFT 8
>> +#define ADS1015_CFG_PGA_SHIFT 9
>> +#define ADS1015_CFG_MUX_SHIFT 12
>> +
>> +#define ADS1015_CFG_DR_MASK GENMASK(7, 5)
>> +#define ADS1015_CFG_MOD_MASK BIT(8)
>> +#define ADS1015_CFG_PGA_MASK GENMASK(11, 9)
>> +#define ADS1015_CFG_MUX_MASK GENMASK(14, 12)
>> +
>> +/* device operating modes */
>> +#define ADS1015_CONTINUOUS 0
>> +#define ADS1015_SINGLESHOT 1
>> +
>> +#define ADS1015_SLEEP_DELAY_MS 2000
>> +#define ADS1015_DEFAULT_PGA 2
>> +#define ADS1015_DEFAULT_DATA_RATE 4
>> +#define ADS1015_DEFAULT_CHAN 0
>> +
>> +enum ads1015_channels {
>> + ADS1015_AIN0_AIN1 = 0,
>> + ADS1015_AIN0_AIN3,
>> + ADS1015_AIN1_AIN3,
>> + ADS1015_AIN2_AIN3,
>> + ADS1015_AIN0,
>> + ADS1015_AIN1,
>> + ADS1015_AIN2,
>> + ADS1015_AIN3,
>> + ADS1015_TIMESTAMP,
>> +};
>> +
>> +static const unsigned int ads1015_data_rate[] = {
>> + 128, 250, 490, 920, 1600, 2400, 3300, 3300
>> +};
>> +
>> +static const struct {
>> + int scale;
>> + int uscale;
>> +} ads1015_scale[] = {
>> + {3, 0},
>> + {2, 0},
>> + {1, 0},
>> + {0, 500000},
>> + {0, 250000},
>> + {0, 125000},
>> + {0, 125000},
>> + {0, 125000},
>> +};
>> +
>> +#define ADS1015_V_CHAN(_chan, _addr) { \
>> + .type = IIO_VOLTAGE, \
>> + .indexed = 1, \
>> + .address = _addr, \
>> + .channel = _chan, \
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
>> + BIT(IIO_CHAN_INFO_SCALE) | \
>> + BIT(IIO_CHAN_INFO_SAMP_FREQ), \
>> + .scan_index = _addr, \
>> + .scan_type = { \
>> + .sign = 's', \
>> + .realbits = 12, \
>> + .storagebits = 16, \
>> + .shift = 4, \
>> + .endianness = IIO_CPU, \
>> + }, \
>> +}
>> +
>> +#define ADS1015_V_DIFF_CHAN(_chan, _chan2, _addr) { \
>> + .type = IIO_VOLTAGE, \
>> + .differential = 1, \
>> + .indexed = 1, \
>> + .address = _addr, \
>> + .channel = _chan, \
>> + .channel2 = _chan2, \
>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
>> + BIT(IIO_CHAN_INFO_SCALE) | \
>> + BIT(IIO_CHAN_INFO_SAMP_FREQ), \
>> + .scan_index = _addr, \
>> + .scan_type = { \
>> + .sign = 's', \
>> + .realbits = 12, \
>> + .storagebits = 16, \
>> + .shift = 4, \
>> + .endianness = IIO_CPU, \
>> + }, \
>> +}
>> +
>> +struct ads1015_data {
>> + struct regmap *regmap;
>> + /*
>> + * Protects ADC ops, e.g: concurrent sysfs/buffered
>> + * data reads, configuration updates
>> + */
>> + struct mutex lock;
>> + struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
>> +};
>> +
>> +static bool ads1015_is_writeable_reg(struct device *dev, unsigned int reg)
>> +{
>> + return (reg == ADS1015_CFG_REG);
>> +}
>> +
>> +static const struct regmap_config ads1015_regmap_config = {
>> + .reg_bits = 8,
>> + .val_bits = 16,
>> + .max_register = ADS1015_CFG_REG,
>> + .writeable_reg = ads1015_is_writeable_reg,
>> +};
>> +
>> +static const struct iio_chan_spec ads1015_channels[] = {
>> + ADS1015_V_DIFF_CHAN(0, 1, ADS1015_AIN0_AIN1),
>> + ADS1015_V_DIFF_CHAN(0, 3, ADS1015_AIN0_AIN3),
>> + ADS1015_V_DIFF_CHAN(1, 3, ADS1015_AIN1_AIN3),
>> + ADS1015_V_DIFF_CHAN(2, 3, ADS1015_AIN2_AIN3),
>> + ADS1015_V_CHAN(0, ADS1015_AIN0),
>> + ADS1015_V_CHAN(1, ADS1015_AIN1),
>> + ADS1015_V_CHAN(2, ADS1015_AIN2),
>> + ADS1015_V_CHAN(3, ADS1015_AIN3),
>> + IIO_CHAN_SOFT_TIMESTAMP(ADS1015_TIMESTAMP),
>> +};
>> +
>> +static int ads1015_set_power_state(struct ads1015_data *data, bool on)
>> +{
>> + int ret;
>> + struct device *dev = regmap_get_device(data->regmap);
>> +
>> + if (on) {
>> + ret = pm_runtime_get_sync(dev);
>> + if (ret < 0)
>> + pm_runtime_put_noidle(dev);
>> + } else {
>> + pm_runtime_mark_last_busy(dev);
>> + ret = pm_runtime_put_autosuspend(dev);
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static
>> +int ads1015_get_adc_result(struct ads1015_data *data, int chan, int *val)
>> +{
>> + int ret, pga, dr, conv_time;
>> + bool change;
>> +
>> + if (chan < 0 || chan >= ADS1015_CHANNELS)
>> + return -EINVAL;
>> +
>> + pga = data->channel_data[chan].pga;
>> + dr = data->channel_data[chan].data_rate;
>> +
>> + ret = regmap_update_bits_check(data->regmap, ADS1015_CFG_REG,
>> + ADS1015_CFG_MUX_MASK |
>> + ADS1015_CFG_PGA_MASK,
>> + chan << ADS1015_CFG_MUX_SHIFT |
>> + pga << ADS1015_CFG_PGA_SHIFT,
>> + &change);
>> + if (ret < 0)
>> + return ret;
>> +
>> + if (change) {
>> + conv_time = DIV_ROUND_UP(USEC_PER_SEC, ads1015_data_rate[dr]);
>> + usleep_range(conv_time, conv_time + 1);
>> + }
>> +
>> + return regmap_read(data->regmap, ADS1015_CONV_REG, val);
>> +}
>> +
>> +static irqreturn_t ads1015_trigger_handler(int irq, void *p)
>> +{
>> + struct iio_poll_func *pf = p;
>> + struct iio_dev *indio_dev = pf->indio_dev;
>> + struct ads1015_data *data = iio_priv(indio_dev);
>> + s16 buf[8]; /* 1x s16 ADC val + 3x s16 padding + 4x s16 timestamp */
>> + int chan, ret, res;
>> +
>> + memset(buf, 0, sizeof(buf));
>> +
>> + mutex_lock(&data->lock);
>> + chan = find_first_bit(indio_dev->active_scan_mask,
>> + indio_dev->masklength);
>> + ret = ads1015_get_adc_result(data, chan, &res);
>> + if (ret < 0) {
>> + mutex_unlock(&data->lock);
>> + goto err;
>> + }
>> +
>> + buf[0] = res;
>> + mutex_unlock(&data->lock);
>> +
>> + iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns());
>> +
>> +err:
>> + iio_trigger_notify_done(indio_dev->trig);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int ads1015_set_scale(struct ads1015_data *data, int chan,
>> + int scale, int uscale)
>> +{
>> + int i, ret, rindex = -1;
>> +
>> + for (i = 0; i < ARRAY_SIZE(ads1015_scale); i++)
>> + if (ads1015_scale[i].scale == scale &&
>> + ads1015_scale[i].uscale == uscale) {
>> + rindex = i;
>> + break;
>> + }
>> + if (rindex < 0)
>> + return -EINVAL;
>> +
>> + ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
>> + ADS1015_CFG_PGA_MASK,
>> + rindex << ADS1015_CFG_PGA_SHIFT);
>> + if (ret < 0)
>> + return ret;
>> +
>> + data->channel_data[chan].pga = rindex;
>> +
>> + return 0;
>> +}
>> +
>> +static int ads1015_set_data_rate(struct ads1015_data *data, int chan, int rate)
>> +{
>> + int i, ret, rindex = -1;
>> +
>> + for (i = 0; i < ARRAY_SIZE(ads1015_data_rate); i++)
>> + if (ads1015_data_rate[i] == rate) {
>> + rindex = i;
>> + break;
>> + }
>> + if (rindex < 0)
>> + return -EINVAL;
>> +
>> + ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
>> + ADS1015_CFG_DR_MASK,
>> + rindex << ADS1015_CFG_DR_SHIFT);
>> + if (ret < 0)
>> + return ret;
>> +
>> + data->channel_data[chan].data_rate = rindex;
>> +
>> + return 0;
>> +}
>> +
>> +static int ads1015_read_raw(struct iio_dev *indio_dev,
>> + struct iio_chan_spec const *chan, int *val,
>> + int *val2, long mask)
>> +{
>> + int ret, idx;
>> + struct ads1015_data *data = iio_priv(indio_dev);
>> +
>> + mutex_lock(&data->lock);
>> + switch (mask) {
>> + case IIO_CHAN_INFO_RAW:
>> + if (iio_buffer_enabled(indio_dev)) {
>> + ret = -EBUSY;
>> + break;
>> + }
>> +
>> + ret = ads1015_set_power_state(data, true);
>> + if (ret < 0)
>> + break;
>
> Just tested the driver on a Dragonboard 410C with a robotics mezzanine that I
> designed.
>
> The above ads1015_set_power_state(data, true) is always returning -EINVAL.
>
> Any ideas why that would be happening?
> I think it may be the return from pm_runtime_get_sync?
Can you confirm that pm_runtime_get_sync fails? Using some printk?
Also adding printks in suspend/resume function would be helpful. Do
you have CONFIG_PM enabled?
>
> When I comment out the break the readings come back but are not updated continually.
> If I read in_voltage0-voltage1_raw then in_voltage0_raw the value is updated.
I guess this is normal if set_power_state fails.
thanks,
Daniel.