Re: [PATCH v4] iio: adc: Add TI ADS1015 ADC driver support

From: Michael Welling
Date: Fri Feb 05 2016 - 14:50:40 EST

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In reply to: Daniel Baluta: "Re: [PATCH v4] iio: adc: Add TI ADS1015 ADC driver support"
Next in thread: Michael Welling: "Re: [PATCH v4] iio: adc: Add TI ADS1015 ADC driver support"
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On Fri, Feb 05, 2016 at 09:32:34PM +0200, Daniel Baluta wrote:
> 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?
>

root@dragonboard-410c:/sys/devices/platform/soc/78b6000.i2c/i2c-0/0-0048/iio:device0# cat in_voltage0_raw
[ 867.065084] mask = 0
[ 867.065104] IIO_CHAN_INFO_RAW
[ 867.066646] error set_power_state IIO_CHAN_INFO_RAW
265

I assumed the only way for the failure to occur is if pm_runtime_get_sync
returns an error in ads1015_set_power_state.

I will add more printks to see if I can find out more.

> Also adding printks in suspend/resume function would be helpful. Do
> you have CONFIG_PM enabled?
#
# Power management options
#
CONFIG_SUSPEND=y
CONFIG_SUSPEND_FREEZER=y
CONFIG_PM_SLEEP=y
CONFIG_PM_SLEEP_SMP=y
# CONFIG_PM_AUTOSLEEP is not set
# CONFIG_PM_WAKELOCKS is not set
CONFIG_PM=y
# CONFIG_PM_DEBUG is not set
CONFIG_PM_CLK=y
CONFIG_PM_GENERIC_DOMAINS=y
# CONFIG_WQ_POWER_EFFICIENT_DEFAULT is not set
CONFIG_PM_GENERIC_DOMAINS_SLEEP=y
CONFIG_PM_GENERIC_DOMAINS_OF=y
CONFIG_CPU_PM=y
CONFIG_ARCH_SUSPEND_POSSIBLE=y

>
> >
> > 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.
>

Yeah the continuous mode is never enabled if the runtime resume is never called.

> thanks,
> Daniel.

Next message: Luck, Tony: "Re: [PATCH -v2] x86: Add an archinfo dumper module"
Previous message: Bjorn Helgaas: "Re: [PATCH v4 2/2] pci, pci-thunder-pem: Add PCIe host driver for ThunderX processors."
In reply to: Daniel Baluta: "Re: [PATCH v4] iio: adc: Add TI ADS1015 ADC driver support"
Next in thread: Michael Welling: "Re: [PATCH v4] iio: adc: Add TI ADS1015 ADC driver support"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]