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From: Michael Hennerich <michael.hennerich@analog.com>
To: Jonathan Cameron <jic23@cam.ac.uk>
Cc: "linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>,
	"device-drivers-devel@blackfin.uclinux.org"
	<device-drivers-devel@blackfin.uclinux.org>,
	Drivers <Drivers@analog.com>
Subject: Re: [PATCH] IIO: ADC: New driver for AD7190/AD7192/AD7195 4 Channel SPI ADC
Date: Wed, 17 Aug 2011 15:47:51 +0200	[thread overview]
Message-ID: <4E4BC687.3050504@analog.com> (raw)
In-Reply-To: <4E452E51.5040203@cam.ac.uk>

On 08/12/2011 03:44 PM, Jonathan Cameron wrote:
> On 08/12/11 13:41, michael.hennerich@analog.com wrote:
>> From: Michael Hennerich<michael.hennerich@analog.com>
>>
>> New driver for AD7190/AD7192/AD7195 4.8 kHz, Ultralow Noise, 24-Bit
>> Sigma-Delta ADC with PGA
>>
>> These devices features a dual use data out ready DOUT/RDY output.
>> In order to avoid contentions on the SPI bus, it's necessary to use
>> spi bus locking. The DOUT/RDY output must also be wired to an
>> interrupt capable GPIO.
>>
>> In INDIO_RING_TRIGGERED mode, this driver may block its SPI bus segment
>> for an extended period of time.
> Couple of nit picks and some missing docs.  Otherwise looks good.
>> Signed-off-by: Michael Hennerich<michael.hennerich@analog.com>
>> ---
>>   drivers/staging/iio/adc/Kconfig  |   14 +
>>   drivers/staging/iio/adc/Makefile |    1 +
>>   drivers/staging/iio/adc/ad7192.c | 1178 ++++++++++++++++++++++++++++++++++++++
>>   drivers/staging/iio/adc/ad7192.h |   47 ++
>>   4 files changed, 1240 insertions(+), 0 deletions(-)
>>   create mode 100644 drivers/staging/iio/adc/ad7192.c
>>   create mode 100644 drivers/staging/iio/adc/ad7192.h
>>
>> diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
>> index b39f2e1..975a9a5 100644
>> --- a/drivers/staging/iio/adc/Kconfig
>> +++ b/drivers/staging/iio/adc/Kconfig
>> @@ -161,6 +161,20 @@ config AD7816
>>          Say yes here to build support for Analog Devices AD7816/7/8
>>          temperature sensors and ADC.
>>
>> +config AD7192
>> +     tristate "Analog Devices AD7190 AD7192 AD7195 ADC driver"
>> +     depends on SPI
>> +     select IIO_RING_BUFFER
>> +     select IIO_SW_RING
>> +     select IIO_TRIGGER
>> +     help
>> +       Say yes here to build support for Analog Devices AD7190,
>> +       AD7192 or AD7195 SPI analog to digital convertors (ADC).
>> +       If unsure, say N (but it's safe to say "Y").
>> +
>> +       To compile this driver as a module, choose M here: the
>> +       module will be called ad7192.
>> +
>>   config ADT75
>>        tristate "Analog Devices ADT75 temperature sensor driver"
>>        depends on I2C
>> diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile
>> index f020351..b72dcd9 100644
>> --- a/drivers/staging/iio/adc/Makefile
>> +++ b/drivers/staging/iio/adc/Makefile
>> @@ -37,6 +37,7 @@ obj-$(CONFIG_AD7745) += ad7745.o
>>   obj-$(CONFIG_AD7780) += ad7780.o
>>   obj-$(CONFIG_AD7793) += ad7793.o
>>   obj-$(CONFIG_AD7816) += ad7816.o
>> +obj-$(CONFIG_AD7192) += ad7192.o
>>   obj-$(CONFIG_ADT75) += adt75.o
>>   obj-$(CONFIG_ADT7310) += adt7310.o
>>   obj-$(CONFIG_ADT7410) += adt7410.o
>> diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
>> new file mode 100644
>> index 0000000..e7e53d2
>> --- /dev/null
>> +++ b/drivers/staging/iio/adc/ad7192.c
>> @@ -0,0 +1,1178 @@
>> +/*
>> + * AD7190 AD7192 AD7195 SPI ADC driver
>> + *
>> + * Copyright 2011 Analog Devices Inc.
>> + *
>> + * Licensed under the GPL-2.
>> + */
>> +
>> +#include<linux/interrupt.h>
>> +#include<linux/device.h>
>> +#include<linux/kernel.h>
>> +#include<linux/slab.h>
>> +#include<linux/sysfs.h>
>> +#include<linux/spi/spi.h>
>> +#include<linux/regulator/consumer.h>
>> +#include<linux/err.h>
>> +#include<linux/sched.h>
>> +#include<linux/delay.h>
>> +
>> +#include "../iio.h"
>> +#include "../sysfs.h"
>> +#include "../ring_generic.h"
>> +#include "../ring_sw.h"
>> +#include "../trigger.h"
>> +#include "adc.h"
> Going... and unused anyway.
>> +
>> +#include "ad7192.h"
>> +
>> +/* Registers */
>> +#define AD7192_REG_COMM              0 /* Communications Register (WO, 8-bit) */
>> +#define AD7192_REG_STAT              0 /* Status Register         (RO, 8-bit) */
>> +#define AD7192_REG_MODE              1 /* Mode Register           (RW, 24-bit */
>> +#define AD7192_REG_CONF              2 /* Configuration Register  (RW, 24-bit) */
>> +#define AD7192_REG_DATA              3 /* Data Register           (RO, 24/32-bit) */
>> +#define AD7192_REG_ID                4 /* ID Register             (RO, 8-bit) */
>> +#define AD7192_REG_GPOCON    5 /* GPOCON Register         (RO, 8-bit) */
>> +#define AD7192_REG_OFFSET    6 /* Offset Register         (RW, 16-bit
>> +                                * (AD7792)/24-bit (AD7192)) */
>> +#define AD7192_REG_FULLSALE  7 /* Full-Scale Register
>> +                                * (RW, 16-bit (AD7792)/24-bit (AD7192)) */
>> +
>> +/* Communications Register Bit Designations (AD7192_REG_COMM) */
>> +#define AD7192_COMM_WEN              (1<<  7) /* Write Enable */
>> +#define AD7192_COMM_WRITE    (0<<  6) /* Write Operation */
>> +#define AD7192_COMM_READ     (1<<  6) /* Read Operation */
>> +#define AD7192_COMM_ADDR(x)  (((x)&  0x7)<<  3) /* Register Address */
>> +#define AD7192_COMM_CREAD    (1<<  2) /* Continuous Read of Data Register */
>> +
>> +/* Status Register Bit Designations (AD7192_REG_STAT) */
>> +#define AD7192_STAT_RDY              (1<<  7) /* Ready */
>> +#define AD7192_STAT_ERR              (1<<  6) /* Error (Overrange, Underrange) */
>> +#define AD7192_STAT_NOREF    (1<<  5) /* Error no external reference */
>> +#define AD7192_STAT_PARITY   (1<<  4) /* Parity */
>> +#define AD7192_STAT_CH3              (1<<  2) /* Channel 3 */
>> +#define AD7192_STAT_CH2              (1<<  1) /* Channel 2 */
>> +#define AD7192_STAT_CH1              (1<<  0) /* Channel 1 */
>> +
>> +/* Mode Register Bit Designations (AD7192_REG_MODE) */
>> +#define AD7192_MODE_SEL(x)   (((x)&  0x7)<<  21) /* Operation Mode Select */
>> +#define AD7192_MODE_DAT_STA  (1<<  20) /* Status Register transmission */
>> +#define AD7192_MODE_CLKSRC(x)        (((x)&  0x3)<<  18) /* Clock Source Select */
>> +#define AD7192_MODE_SINC3    (1<<  15) /* SINC3 Filter Select */
>> +#define AD7192_MODE_ACX              (1<<  14) /* AC excitation enable(AD7195 only)*/
>> +#define AD7192_MODE_ENPAR    (1<<  13) /* Parity Enable */
>> +#define AD7192_MODE_CLKDIV   (1<<  12) /* Clock divide by 2 (AD7190/2 only)*/
>> +#define AD7192_MODE_SCYCLE   (1<<  11) /* Single cycle conversion */
>> +#define AD7192_MODE_REJ60    (1<<  10) /* 50/60Hz notch filter */
>> +#define AD7192_MODE_RATE(x)  ((x)&  0x3FF) /* Filter Update Rate Select */
>> +
>> +/* Mode Register: AD7192_MODE_SEL options */
>> +#define AD7192_MODE_CONT             0 /* Continuous Conversion Mode */
>> +#define AD7192_MODE_SINGLE           1 /* Single Conversion Mode */
>> +#define AD7192_MODE_IDLE             2 /* Idle Mode */
>> +#define AD7192_MODE_PWRDN            3 /* Power-Down Mode */
>> +#define AD7192_MODE_CAL_INT_ZERO     4 /* Internal Zero-Scale Calibration */
>> +#define AD7192_MODE_CAL_INT_FULL     5 /* Internal Full-Scale Calibration */
>> +#define AD7192_MODE_CAL_SYS_ZERO     6 /* System Zero-Scale Calibration */
>> +#define AD7192_MODE_CAL_SYS_FULL     7 /* System Full-Scale Calibration */
>> +
>> +/* Mode Register: AD7192_MODE_CLKSRC options */
>> +#define AD7192_CLK_EXT_MCLK1_2               0 /* External 4.92 MHz Clock connected
>> +                                        * from MCLK1 to MCLK2 */
>> +#define AD7192_CLK_EXT_MCLK2         1 /* External Clock applied to MCLK2 */
>> +#define AD7192_CLK_INT                       2 /* Internal 4.92 MHz Clock not
>> +                                        * available at the MCLK2 pin */
>> +#define AD7192_CLK_INT_CO            3 /* Internal 4.92 MHz Clock available
>> +                                        * at the MCLK2 pin */
>> +
>> +
>> +/* Configuration Register Bit Designations (AD7192_REG_CONF) */
>> +
>> +#define AD7192_CONF_CHOP     (1<<  23) /* CHOP enable */
>> +#define AD7192_CONF_REFSEL   (1<<  20) /* REFIN1/REFIN2 Reference Select */
>> +#define AD7192_CONF_CHAN(x)  (((x)&  0xFF)<<  8) /* Channel select */
>> +#define AD7192_CONF_BURN     (1<<  7) /* Burnout current enable */
>> +#define AD7192_CONF_REFDET   (1<<  6) /* Reference detect enable */
>> +#define AD7192_CONF_BUF              (1<<  4) /* Buffered Mode Enable */
>> +#define AD7192_CONF_UNIPOLAR (1<<  3) /* Unipolar/Bipolar Enable */
>> +#define AD7192_CONF_GAIN(x)  ((x)&  0x7) /* Gain Select */
>> +
>> +#define AD7192_CH_AIN1P_AIN2M        0 /* AIN1(+) - AIN2(-) */
>> +#define AD7192_CH_AIN3P_AIN4M        1 /* AIN3(+) - AIN4(-) */
>> +#define AD7192_CH_TEMP               2 /* Temp Sensor */
>> +#define AD7192_CH_AIN2P_AIN2M        3 /* AIN2(+) - AIN2(-) */
>> +#define AD7192_CH_AIN1               4 /* AIN1 - AINCOM */
>> +#define AD7192_CH_AIN2               5 /* AIN2 - AINCOM */
>> +#define AD7192_CH_AIN3               6 /* AIN3 - AINCOM */
>> +#define AD7192_CH_AIN4               7 /* AIN4 - AINCOM */
>> +
>> +/* ID Register Bit Designations (AD7192_REG_ID) */
>> +#define ID_AD7190            0x4
>> +#define ID_AD7192            0x0
>> +#define ID_AD7195            0x6
>> +#define AD7192_ID_MASK               0x0F
>> +
>> +/* GPOCON Register Bit Designations (AD7192_REG_GPOCON) */
>> +#define AD7192_GPOCON_BPDSW  (1<<  6) /* Bridge power-down switch enable */
>> +#define AD7192_GPOCON_GP32EN (1<<  5) /* Digital Output P3 and P2 enable */
>> +#define AD7192_GPOCON_GP10EN (1<<  4) /* Digital Output P1 and P0 enable */
>> +#define AD7192_GPOCON_P3DAT  (1<<  3) /* P3 state */
>> +#define AD7192_GPOCON_P2DAT  (1<<  2) /* P2 state */
>> +#define AD7192_GPOCON_P1DAT  (1<<  1) /* P1 state */
>> +#define AD7192_GPOCON_P0DAT  (1<<  0) /* P0 state */
>> +
>> +#define AD7192_INT_FREQ_MHz  4915200
>> +
>> +/* NOTE:
>> + * The AD7190/2/5sold features a dual use data out ready DOUT/RDY output.
> sold?
typo...
>> + * In order to avoid contentions on the SPI bus, it's therefore necessary
>> + * to use spi bus locking.
>> + *
>> + * The DOUT/RDY output must also be wired to an interrupt capable GPIO.
>> + */
>> +
>> +struct ad7192_state {
>> +     struct spi_device               *spi;
>> +     struct iio_trigger              *trig;
>> +     struct regulator                *reg;
>> +     struct ad7192_platform_data     *pdata;
>> +     wait_queue_head_t               wq_data_avail;
>> +     bool                            done;
>> +     bool                            irq_dis;
>> +     u16                             int_vref_mv;
>> +     u32                             mclk;
>> +     u32                             f_order;
>> +     u32                             mode;
>> +     u32                             conf;
>> +     u32                             scale_avail[8][2];
>> +     u32                             available_scan_masks[9];
>> +     u8                              gpocon;
>> +     u8                              devid;
>> +     /*
>> +      * DMA (thus cache coherency maintenance) requires the
>> +      * transfer buffers to live in their own cache lines.
>> +      */
> I may be missing something but this seems somewhat large.
leftover from some debug test - 4 bytes are sufficient.

>> +     u8                              data[32] ____cacheline_aligned;
>> +};
>> +
>> +static int __ad7192_write_reg(struct ad7192_state *st, bool locked,
>> +                           bool cs_change, unsigned char reg,
>> +                           unsigned size, unsigned val)
>> +{
>> +     u8 *data = st->data;
>> +     struct spi_transfer t = {
>> +             .tx_buf         = data,
>> +             .len            = size + 1,
>> +             .cs_change      = cs_change,
>> +     };
>> +     struct spi_message m;
>> +
>> +     data[0] = AD7192_COMM_WRITE | AD7192_COMM_ADDR(reg);
>> +
>> +     switch (size) {
>> +     case 3:
>> +             data[1] = val>>  16;
>> +             data[2] = val>>  8;
>> +             data[3] = val;
>> +             break;
>> +     case 2:
>> +             data[1] = val>>  8;
>> +             data[2] = val;
>> +             break;
>> +     case 1:
>> +             data[1] = val;
>> +             break;
>> +     default:
>> +             return -EINVAL;
>> +     }
>> +
>> +     spi_message_init(&m);
>> +     spi_message_add_tail(&t,&m);
>> +
>> +     if (locked)
>> +             return spi_sync_locked(st->spi,&m);
>> +     else
>> +             return spi_sync(st->spi,&m);
>> +}
>> +
>> +static int ad7192_write_reg(struct ad7192_state *st,
>> +                         unsigned reg, unsigned size, unsigned val)
>> +{
>> +     return __ad7192_write_reg(st, false, false, reg, size, val);
>> +}
>> +
>> +static int __ad7192_read_reg(struct ad7192_state *st, bool locked,
>> +                          bool cs_change, unsigned char reg,
>> +                          int *val, unsigned size)
>> +{
>> +     u8 *data = st->data;
>> +     int ret;
>> +     struct spi_transfer t[] = {
>> +             {
>> +                     .tx_buf = data,
>> +                     .len = 1,
>> +             }, {
>> +                     .rx_buf = data,
>> +                     .len = size,
>> +                     .cs_change = cs_change,
>> +             },
>> +     };
>> +     struct spi_message m;
>> +
>> +     data[0] = AD7192_COMM_READ | AD7192_COMM_ADDR(reg);
>> +
>> +     spi_message_init(&m);
>> +     spi_message_add_tail(&t[0],&m);
>> +     spi_message_add_tail(&t[1],&m);
>> +
>> +     if (locked)
>> +             ret = spi_sync_locked(st->spi,&m);
>> +     else
>> +             ret = spi_sync(st->spi,&m);
>> +
>> +     if (ret<  0)
>> +             return ret;
>> +
>> +     switch (size) {
>> +     case 3:
>> +             *val = data[0]<<  16 | data[1]<<  8 | data[2];
>> +             break;
>> +     case 2:
>> +             *val = data[0]<<  8 | data[1];
>> +             break;
>> +     case 1:
>> +             *val = data[0];
>> +             break;
>> +     default:
>> +             return -EINVAL;
>> +     }
>> +
>> +     return 0;
>> +}
>> +
>> +static int ad7192_read_reg(struct ad7192_state *st,
>> +                        unsigned reg, int *val, unsigned size)
>> +{
>> +     return __ad7192_read_reg(st, 0, 0, reg, val, size);
>> +}
>> +
>> +static int ad7192_read(struct ad7192_state *st, unsigned ch,
>> +                    unsigned len, int *val)
>> +{
>> +     int ret;
>> +     st->conf = (st->conf&  ~AD7192_CONF_CHAN(-1)) |
>> +             AD7192_CONF_CHAN(1<<  ch);
>> +     st->mode = (st->mode&  ~AD7192_MODE_SEL(-1)) |
>> +             AD7192_MODE_SEL(AD7192_MODE_SINGLE);
>> +
>> +     ad7192_write_reg(st, AD7192_REG_CONF, 3, st->conf);
>> +
>> +     spi_bus_lock(st->spi->master);
>> +     st->done = false;
>> +
>> +     ret = __ad7192_write_reg(st, 1, 1, AD7192_REG_MODE, 3, st->mode);
>> +     if (ret<  0)
>> +             goto out;
>> +
>> +     st->irq_dis = false;
>> +     enable_irq(st->spi->irq);
>> +     wait_event_interruptible(st->wq_data_avail, st->done);
>> +
>> +     ret = __ad7192_read_reg(st, 1, 0, AD7192_REG_DATA, val, len);
>> +out:
>> +     spi_bus_unlock(st->spi->master);
>> +
>> +     return ret;
>> +}
>> +
>> +static int ad7192_calibrate(struct ad7192_state *st, unsigned mode, unsigned ch)
>> +{
>> +     int ret;
>> +
>> +     st->conf = (st->conf&  ~AD7192_CONF_CHAN(-1)) |
>> +             AD7192_CONF_CHAN(1<<  ch);
>> +     st->mode = (st->mode&  ~AD7192_MODE_SEL(-1)) | AD7192_MODE_SEL(mode);
>> +
>> +     ad7192_write_reg(st, AD7192_REG_CONF, 3, st->conf);
>> +
>> +     spi_bus_lock(st->spi->master);
>> +     st->done = false;
>> +
>> +     ret = __ad7192_write_reg(st, 1, 1, AD7192_REG_MODE, 3,
>> +                              (st->devid != ID_AD7195) ?
>> +                              st->mode | AD7192_MODE_CLKDIV :
>> +                              st->mode);
>> +     if (ret<  0)
>> +             goto out;
>> +
>> +     st->irq_dis = false;
>> +     enable_irq(st->spi->irq);
>> +     wait_event_interruptible(st->wq_data_avail, st->done);
>> +
>> +     st->mode = (st->mode&  ~AD7192_MODE_SEL(-1)) |
>> +             AD7192_MODE_SEL(AD7192_MODE_IDLE);
>> +
>> +     ret = __ad7192_write_reg(st, 1, 0, AD7192_REG_MODE, 3, st->mode);
>> +out:
>> +     spi_bus_unlock(st->spi->master);
>> +
>> +     return ret;
>> +}
>> +
>> +static const u8 ad7192_calib_arr[8][2] = {
>> +     {AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN1},
>> +     {AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN1},
>> +     {AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN2},
>> +     {AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN2},
>> +     {AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN3},
>> +     {AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN3},
>> +     {AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN4},
>> +     {AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN4}
>> +};
>> +
>> +static int ad7192_calibrate_all(struct ad7192_state *st)
>> +{
>> +     int i, ret;
>> +
>> +     for (i = 0; i<  ARRAY_SIZE(ad7192_calib_arr); i++) {
>> +             ret = ad7192_calibrate(st, ad7192_calib_arr[i][0],
>> +                                    ad7192_calib_arr[i][1]);
>> +             if (ret)
>> +                     goto out;
>> +     }
>> +
>> +     return 0;
>> +out:
>> +     dev_err(&st->spi->dev, "Calibration failed\n");
>> +     return ret;
>> +}
>> +
>> +static int ad7192_setup(struct ad7192_state *st)
>> +{
>> +     struct iio_dev *indio_dev = spi_get_drvdata(st->spi);
>> +     struct ad7192_platform_data *pdata = st->pdata;
>> +     unsigned long long scale_uv;
>> +     int i, ret, id;
>> +     u8 ones[6];
>> +
>> +     /* reset the serial interface */
>> +     memset(&ones, 0xFF, 6);
>> +     ret = spi_write(st->spi,&ones, 6);
>> +     if (ret<  0)
>> +             goto out;
>> +     msleep(1); /* Wait for at least 500us */
>> +
>> +     /* write/read test for device presence */
>> +     ret = ad7192_read_reg(st, AD7192_REG_ID,&id, 1);
>> +     if (ret)
>> +             goto out;
>> +
>> +     id&= AD7192_ID_MASK;
>> +
>> +     if (id != st->devid)
>> +             dev_warn(&st->spi->dev, "device ID query failed (0x%X)\n", id);
>> +
>> +     switch (pdata->clock_source_sel) {
>> +     case AD7192_CLK_EXT_MCLK1_2:
>> +     case AD7192_CLK_EXT_MCLK2:
>> +             st->mclk = AD7192_INT_FREQ_MHz;
>> +             break;
>> +     case AD7192_CLK_INT:
>> +     case AD7192_CLK_INT_CO:
>> +             if (pdata->ext_clk_Hz)
>> +                     st->mclk = pdata->ext_clk_Hz;
>> +             else
>> +                     st->mclk = AD7192_INT_FREQ_MHz;
>> +                     break;
>> +     default:
>> +             ret = -EINVAL;
>> +             goto out;
>> +     }
>> +
>> +     st->mode = AD7192_MODE_SEL(AD7192_MODE_IDLE) |
>> +             AD7192_MODE_CLKSRC(pdata->clock_source_sel) |
>> +             AD7192_MODE_RATE(480);
>> +
>> +     st->conf = AD7192_CONF_GAIN(0);
>> +
>> +     if (pdata->rej60_en)
>> +             st->mode |= AD7192_MODE_REJ60;
>> +
>> +     if (pdata->sinc3_en)
>> +             st->mode |= AD7192_MODE_SINC3;
>> +
>> +     if (pdata->refin2_en&&  (st->devid != ID_AD7195))
>> +             st->conf |= AD7192_CONF_REFSEL;
>> +
>> +     if (pdata->chop_en) {
>> +             st->conf |= AD7192_CONF_CHOP;
>> +             if (pdata->sinc3_en)
>> +                     st->f_order = 3; /* SINC 3rd order */
>> +             else
> Inconsistent spacing in comments.
>> +                     st->f_order = 4; /*SINC 4th order*/
>> +     } else {
>> +             st->f_order = 1;
>> +     }
>> +
>> +     if (pdata->buf_en)
>> +             st->conf |= AD7192_CONF_BUF;
>> +
>> +     if (pdata->unipolar_en)
>> +             st->conf |= AD7192_CONF_UNIPOLAR;
>> +
>> +     if (pdata->burnout_curr_en)
>> +             st->conf |= AD7192_CONF_BURN;
>> +
>> +     ret = ad7192_write_reg(st, AD7192_REG_MODE, 3, st->mode);
>> +     if (ret)
>> +             goto out;
>> +
>> +     ret = ad7192_write_reg(st, AD7192_REG_CONF, 3, st->conf);
>> +     if (ret)
>> +             goto out;
>> +
>> +     ret = ad7192_calibrate_all(st);
>> +     if (ret)
>> +             goto out;
>> +
>> +     /* Populate available ADC input ranges */
>> +     for (i = 0; i<  ARRAY_SIZE(st->scale_avail); i++) {
>> +             scale_uv = ((u64)st->int_vref_mv * 100000000)
>> +>>  (indio_dev->channels[0].scan_type.realbits -
>> +                     (!!(st->conf&  AD7192_CONF_UNIPOLAR) ? 0 : 1));
>    That ternary operator looks weird.  is that not just !(st->conf&  AD7192_UNIPOLAR) ?
needless !! only...
In unipolar operation the we have 2^N, in bipolar it's 2^(N-1)
>> +             scale_uv>>= i;
>> +
>> +             st->scale_avail[i][1] = do_div(scale_uv, 100000000) * 10;
>> +             st->scale_avail[i][0] = scale_uv;
>> +     }
>> +
>> +     return 0;
>> +out:
>> +     dev_err(&st->spi->dev, "setup failed\n");
>> +     return ret;
>> +}
>> +
>> +static int ad7192_scan_from_ring(struct ad7192_state *st, unsigned ch, int *val)
>> +{
>> +     struct iio_ring_buffer *ring = iio_priv_to_dev(st)->ring;
>> +     int ret;
>> +     s64 dat64[2];
>> +     u32 *dat32 = (u32 *)dat64;
>> +
>> +     if (!(ring->scan_mask&  (1<<  ch)))
>> +             return  -EBUSY;
>> +
>> +     ret = ring->access->read_last(ring, (u8 *)&dat64);
>> +     if (ret)
>> +             return ret;
>> +
>> +     *val = *dat32;
>> +
>> +     return 0;
>> +}
>> +
>> +static int ad7192_ring_preenable(struct iio_dev *indio_dev)
>> +{
>> +     struct ad7192_state *st = iio_priv(indio_dev);
>> +     struct iio_ring_buffer *ring = indio_dev->ring;
>> +     size_t d_size;
>> +     unsigned channel;
>> +
>> +     if (!ring->scan_count)
>> +             return -EINVAL;
>> +
>> +     channel = __ffs(ring->scan_mask);
>> +
>> +     d_size = ring->scan_count *
>> +              indio_dev->channels[0].scan_type.storagebits / 8;
>> +
>> +     if (ring->scan_timestamp) {
>> +             d_size += sizeof(s64);
>> +
>> +             if (d_size % sizeof(s64))
>> +                     d_size += sizeof(s64) - (d_size % sizeof(s64));
>> +     }
>> +
>> +     if (indio_dev->ring->access->set_bytes_per_datum)
>> +             indio_dev->ring->access->set_bytes_per_datum(indio_dev->ring,
>> +                                                          d_size);
>> +
>> +     st->mode  = (st->mode&  ~AD7192_MODE_SEL(-1)) |
>> +                 AD7192_MODE_SEL(AD7192_MODE_CONT);
>> +     st->conf  = (st->conf&  ~AD7192_CONF_CHAN(-1)) |
>> +                 AD7192_CONF_CHAN(1<<  indio_dev->channels[channel].address);
>> +
>> +     ad7192_write_reg(st, AD7192_REG_CONF, 3, st->conf);
>> +
>> +     spi_bus_lock(st->spi->master);
>> +     __ad7192_write_reg(st, 1, 1, AD7192_REG_MODE, 3, st->mode);
>> +
>> +     st->irq_dis = false;
>> +     enable_irq(st->spi->irq);
>> +
>> +     return 0;
>> +}
>> +
>> +static int ad7192_ring_postdisable(struct iio_dev *indio_dev)
>> +{
>> +     struct ad7192_state *st = iio_priv(indio_dev);
>> +
>> +     st->mode  = (st->mode&  ~AD7192_MODE_SEL(-1)) |
>> +                 AD7192_MODE_SEL(AD7192_MODE_IDLE);
>> +
>> +     st->done = false;
>> +     wait_event_interruptible(st->wq_data_avail, st->done);
>> +
>> +     if (!st->irq_dis)
>> +             disable_irq_nosync(st->spi->irq);
>> +
>> +     __ad7192_write_reg(st, 1, 0, AD7192_REG_MODE, 3, st->mode);
>> +
>> +     return spi_bus_unlock(st->spi->master);
>> +}
>> +
>> +/**
>> + * ad7192_trigger_handler() bh of trigger launched polling to ring buffer
>> + **/
> Unwanted blank line?
>> +
>> +static irqreturn_t ad7192_trigger_handler(int irq, void *p)
>> +{
>> +     struct iio_poll_func *pf = p;
>> +     struct iio_dev *indio_dev = pf->private_data;
>> +     struct iio_ring_buffer *ring = indio_dev->ring;
>> +     struct ad7192_state *st = iio_priv(indio_dev);
>> +     s64 dat64[2];
>> +     s32 *dat32 = (s32 *)dat64;
>> +
>> +     if (ring->scan_count)
>> +             __ad7192_read_reg(st, 1, 1, AD7192_REG_DATA,
>> +                               dat32,
>> +                               indio_dev->channels[0].scan_type.realbits/8);
>> +
>> +     /* Guaranteed to be aligned with 8 byte boundary */
>> +     if (ring->scan_timestamp)
>> +             dat64[1] = pf->timestamp;
>> +
>> +     ring->access->store_to(ring, (u8 *)dat64, pf->timestamp);
>> +
>> +     iio_trigger_notify_done(indio_dev->trig);
>> +     st->irq_dis = false;
>> +     enable_irq(st->spi->irq);
>> +
>> +     return IRQ_HANDLED;
>> +}
>> +
>> +static const struct iio_ring_setup_ops ad7192_ring_setup_ops = {
>> +     .preenable =&ad7192_ring_preenable,
>> +     .postenable =&iio_triggered_ring_postenable,
>> +     .predisable =&iio_triggered_ring_predisable,
>> +     .postdisable =&ad7192_ring_postdisable,
>> +};
>> +
>> +static int ad7192_register_ring_funcs_and_init(struct iio_dev *indio_dev)
>> +{
>> +     int ret;
>> +
>> +     indio_dev->ring = iio_sw_rb_allocate(indio_dev);
>> +     if (!indio_dev->ring) {
>> +             ret = -ENOMEM;
>> +             goto error_ret;
>> +     }
>> +     /* Effectively select the ring buffer implementation */
>> +     indio_dev->ring->access =&ring_sw_access_funcs;
>> +     indio_dev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
>> +&ad7192_trigger_handler,
>> +                                              IRQF_ONESHOT,
>> +                                              indio_dev,
>> +                                              "ad7192_consumer%d",
>> +                                              indio_dev->id);
>> +     if (indio_dev->pollfunc == NULL) {
>> +             ret = -ENOMEM;
>> +             goto error_deallocate_sw_rb;
>> +     }
>> +
>> +     /* Ring buffer functions - here trigger setup related */
>> +     indio_dev->ring->setup_ops =&ad7192_ring_setup_ops;
>> +
>> +     /* Flag that polled ring buffering is possible */
>> +     indio_dev->modes |= INDIO_RING_TRIGGERED;
>> +     return 0;
>> +
>> +error_deallocate_sw_rb:
>> +     iio_sw_rb_free(indio_dev->ring);
>> +error_ret:
>> +     return ret;
>> +}
>> +
>> +static void ad7192_ring_cleanup(struct iio_dev *indio_dev)
>> +{
>> +     /* ensure that the trigger has been detached */
>> +     if (indio_dev->trig) {
>> +             iio_put_trigger(indio_dev->trig);
>> +             iio_trigger_dettach_poll_func(indio_dev->trig,
>> +                                           indio_dev->pollfunc);
>> +     }
>> +     iio_dealloc_pollfunc(indio_dev->pollfunc);
>> +     iio_sw_rb_free(indio_dev->ring);
>> +}
>> +
>> +/**
>> + * ad7192_data_rdy_trig_poll() the event handler for the data rdy trig
>> + **/
>> +static irqreturn_t ad7192_data_rdy_trig_poll(int irq, void *private)
>> +{
>> +     struct ad7192_state *st = iio_priv(private);
>> +
>> +     st->done = true;
>> +     wake_up_interruptible(&st->wq_data_avail);
>> +     disable_irq_nosync(irq);
>> +     st->irq_dis = true;
>> +     iio_trigger_poll(st->trig, iio_get_time_ns());
>> +
>> +     return IRQ_HANDLED;
>> +}
>> +
>> +static int ad7192_probe_trigger(struct iio_dev *indio_dev)
>> +{
>> +     struct ad7192_state *st = iio_priv(indio_dev);
>> +     int ret;
>> +
>> +     st->trig = iio_allocate_trigger("%s-dev%d",
>> +                                     spi_get_device_id(st->spi)->name,
>> +                                     indio_dev->id);
>> +     if (st->trig == NULL) {
>> +             ret = -ENOMEM;
>> +             goto error_ret;
>> +     }
>> +
>> +     ret = request_irq(st->spi->irq,
>> +                       ad7192_data_rdy_trig_poll,
>> +                       IRQF_TRIGGER_LOW,
>> +                       spi_get_device_id(st->spi)->name,
>> +                       indio_dev);
>> +     if (ret)
>> +             goto error_free_trig;
>> +
>> +     disable_irq_nosync(st->spi->irq);
>> +     st->irq_dis = true;
>> +     st->trig->dev.parent =&st->spi->dev;
>> +     st->trig->owner = THIS_MODULE;
>> +     st->trig->private_data = indio_dev;
>> +
>> +     ret = iio_trigger_register(st->trig);
>> +
>> +     /* select default trigger */
>> +     indio_dev->trig = st->trig;
>> +     if (ret)
>> +             goto error_free_irq;
>> +
>> +     return 0;
>> +
>> +error_free_irq:
>> +     free_irq(st->spi->irq, indio_dev);
>> +error_free_trig:
>> +     iio_free_trigger(st->trig);
>> +error_ret:
>> +     return ret;
>> +}
>> +
>> +static void ad7192_remove_trigger(struct iio_dev *indio_dev)
>> +{
>> +     struct ad7192_state *st = iio_priv(indio_dev);
>> +
>> +     iio_trigger_unregister(st->trig);
>> +     free_irq(st->spi->irq, indio_dev);
>> +     iio_free_trigger(st->trig);
>> +}
>> +
>> +static ssize_t ad7192_read_frequency(struct device *dev,
>> +             struct device_attribute *attr,
>> +             char *buf)
>> +{
>> +     struct iio_dev *indio_dev = dev_get_drvdata(dev);
>> +     struct ad7192_state *st = iio_priv(indio_dev);
>> +
>> +     return sprintf(buf, "%d\n", st->mclk /
>> +                     (st->f_order * 1024 * AD7192_MODE_RATE(st->mode)));
>> +}
>> +
>> +static ssize_t ad7192_write_frequency(struct device *dev,
>> +             struct device_attribute *attr,
>> +             const char *buf,
>> +             size_t len)
>> +{
>> +     struct iio_dev *indio_dev = dev_get_drvdata(dev);
>> +     struct ad7192_state *st = iio_priv(indio_dev);
>> +     unsigned long lval;
>> +     int div, ret;
>> +
>> +     ret = strict_strtoul(buf, 10,&lval);
>> +     if (ret)
>> +             return ret;
>> +
>> +     mutex_lock(&indio_dev->mlock);
>> +     if (iio_ring_enabled(indio_dev)) {
>> +             mutex_unlock(&indio_dev->mlock);
>> +             return -EBUSY;
>> +     }
>> +
>> +     div = st->mclk / (lval * st->f_order * 1024);
>> +     if (div<  1 || div>  1023) {
>> +             ret = -EINVAL;
>> +             goto out;
>> +     }
>> +
>> +     st->mode&= ~AD7192_MODE_RATE(-1);
>> +     st->mode |= AD7192_MODE_RATE(div);
>> +     ad7192_write_reg(st, AD7192_REG_MODE, 3, st->mode);
>> +
>> +out:
>> +     mutex_unlock(&indio_dev->mlock);
>> +
>> +     return ret ? ret : len;
>> +}
>> +
>> +static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
>> +             ad7192_read_frequency,
>> +             ad7192_write_frequency);
>> +
>> +
>> +static ssize_t ad7192_show_scale_available(struct device *dev,
>> +                     struct device_attribute *attr, char *buf)
>> +{
>> +     struct iio_dev *indio_dev = dev_get_drvdata(dev);
>> +     struct ad7192_state *st = iio_priv(indio_dev);
>> +     int i, len = 0;
>> +
>> +     for (i = 0; i<  ARRAY_SIZE(st->scale_avail); i++)
>> +             len += sprintf(buf + len, "%d.%09u ", st->scale_avail[i][0],
>> +                            st->scale_avail[i][1]);
>> +
>> +     len += sprintf(buf + len, "\n");
>> +
>> +     return len;
>> +}
>> +
>> +static IIO_DEVICE_ATTR_NAMED(in_m_in_scale_available, in-in_scale_available,
>> +                          S_IRUGO, ad7192_show_scale_available, NULL, 0);
>> +
>> +static IIO_DEVICE_ATTR(in_scale_available, S_IRUGO,
>> +                    ad7192_show_scale_available, NULL, 0);
>> +
> For readability I'd just break this into two functions.
ok
>> +static ssize_t ad7192_show(struct device *dev,
>> +             struct device_attribute *attr,
>> +             char *buf)
>> +{
>> +     struct iio_dev *indio_dev = dev_get_drvdata(dev);
>> +     struct ad7192_state *st = iio_priv(indio_dev);
>> +     struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
>> +
>> +     return sprintf(buf, "%d\n", (this_attr->address == AD7192_REG_GPOCON) ?
>> +             !!(st->gpocon&  AD7192_GPOCON_BPDSW) :
>> +             !!(st->mode&  AD7192_MODE_ACX));
>> +}
>> +
>> +static ssize_t ad7192_set(struct device *dev,
>> +             struct device_attribute *attr,
>> +             const char *buf,
>> +             size_t len)
>> +{
>> +     struct iio_dev *indio_dev = dev_get_drvdata(dev);
>> +     struct ad7192_state *st = iio_priv(indio_dev);
>> +     struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
>> +     int ret;
>> +     bool val;
>> +
>> +     ret = strtobool(buf,&val);
>> +     if (ret<  0)
>> +             return ret;
>> +
>> +     mutex_lock(&indio_dev->mlock);
>> +     if (iio_ring_enabled(indio_dev)) {
>> +             mutex_unlock(&indio_dev->mlock);
>> +             return -EBUSY;
>> +     }
>> +
>> +     switch (this_attr->address) {
>> +     case AD7192_REG_GPOCON:
>> +             if (val)
>> +                     st->gpocon |= AD7192_GPOCON_BPDSW;
>> +             else
>> +                     st->gpocon&= ~AD7192_GPOCON_BPDSW;
>> +
>> +             ad7192_write_reg(st, AD7192_REG_GPOCON, 1, st->gpocon);
>> +             break;
>> +     case AD7192_REG_MODE:
>> +             if (val)
>> +                     st->mode |= AD7192_MODE_ACX;
>> +             else
>> +                     st->mode&= ~AD7192_MODE_ACX;
>> +
>> +             ad7192_write_reg(st, AD7192_REG_GPOCON, 3, st->mode);
>> +             break;
>> +     default:
>> +             ret = -EINVAL;
>> +     }
>> +
>> +     mutex_unlock(&indio_dev->mlock);
>> +
>> +     return ret ? ret : len;
>> +}
>> +
>> +static IIO_DEVICE_ATTR(bridge_switch_en, S_IRUGO | S_IWUSR,
>> +                    ad7192_show, ad7192_set,
>> +                    AD7192_REG_GPOCON);
>> +
>> +static IIO_DEVICE_ATTR(ac_excitation_en, S_IRUGO | S_IWUSR,
>> +                    ad7192_show, ad7192_set,
>> +                    AD7192_REG_MODE);
>> +
>> +static struct attribute *ad7192_attributes[] = {
>> +&iio_dev_attr_sampling_frequency.dev_attr.attr,
>> +&iio_dev_attr_in_m_in_scale_available.dev_attr.attr,
>> +&iio_dev_attr_in_scale_available.dev_attr.attr,
>> +&iio_dev_attr_bridge_switch_en.dev_attr.attr,
> Docs please.
>> +&iio_dev_attr_ac_excitation_en.dev_attr.attr,
> Docs please.
ok
>> +     NULL
>> +};
>> +
>> +static mode_t ad7192_attr_is_visible(struct kobject *kobj,
>> +                                  struct attribute *attr, int n)
>> +{
>> +     struct device *dev = container_of(kobj, struct device, kobj);
>> +     struct iio_dev *dev_info = dev_get_drvdata(dev);
>> +     struct ad7192_state *st = iio_priv(dev_info);
>> +
>> +     mode_t mode = attr->mode;
>> +
>> +     if ((st->devid != ID_AD7195)&&
>> +             (attr ==&iio_dev_attr_ac_excitation_en.dev_attr.attr))
>> +             mode = 0;
>> +
>> +     return mode;
>> +}
>> +
>> +static const struct attribute_group ad7192_attribute_group = {
>> +     .attrs = ad7192_attributes,
>> +     .is_visible = ad7192_attr_is_visible,
>> +};
>> +
>> +static int ad7192_read_raw(struct iio_dev *indio_dev,
>> +                        struct iio_chan_spec const *chan,
>> +                        int *val,
>> +                        int *val2,
>> +                        long m)
>> +{
>> +     struct ad7192_state *st = iio_priv(indio_dev);
>> +     int ret, smpl = 0;
>> +     bool unipolar = !!(st->conf&  AD7192_CONF_UNIPOLAR);
>> +
>> +     switch (m) {
>> +     case 0:
>> +             mutex_lock(&indio_dev->mlock);
>> +             if (iio_ring_enabled(indio_dev))
>> +                     ret = ad7192_scan_from_ring(st,
>> +                                     chan->scan_index,&smpl);
>> +             else
>> +                     ret = ad7192_read(st, chan->address,
>> +                                     chan->scan_type.realbits / 8,&smpl);
>> +             mutex_unlock(&indio_dev->mlock);
>> +
>> +             if (ret<  0)
>> +                     return ret;
>> +
>> +             *val = (smpl>>  chan->scan_type.shift)&
>> +                     ((1<<  (chan->scan_type.realbits)) - 1);
>> +
>> +             switch (chan->type) {
>> +             case IIO_IN:
>> +             case IIO_IN_DIFF:
>> +                     if (!unipolar)
>> +                             *val -= (1<<  (chan->scan_type.realbits - 1));
>> +                     break;
>> +             case IIO_TEMP:
>> +                     *val -= 0x800000;
>> +                     *val /= 2815; /* temp Kelvin */
>> +                     *val -= 273; /* temp Celsius */
>> +                     break;
>> +             default:
>> +                     return -EINVAL;
>> +             }
>> +             return IIO_VAL_INT;
>> +
> Could in theory hit a race between reading and writing this (and get inconsistent
> pair of val and val2?)
ok - lets protect it by mutex.
>> +     case (1<<  IIO_CHAN_INFO_SCALE_SHARED):
>> +             *val = st->scale_avail[AD7192_CONF_GAIN(st->conf)][0];
>> +             *val2 = st->scale_avail[AD7192_CONF_GAIN(st->conf)][1];
>> +
>> +             return IIO_VAL_INT_PLUS_NANO;
>> +
>> +     case (1<<  IIO_CHAN_INFO_SCALE_SEPARATE):
>> +             *val =  1000;
>> +
>> +             return IIO_VAL_INT;
>> +     }
>> +
>> +     return -EINVAL;
>> +}
>> +
>> +static int ad7192_write_raw(struct iio_dev *indio_dev,
>> +                            struct iio_chan_spec const *chan,
>> +                            int val,
>> +                            int val2,
>> +                            long mask)
>> +{
>> +     struct ad7192_state *st = iio_priv(indio_dev);
>> +     int ret, i;
>> +     unsigned int tmp;
>> +
>> +     mutex_lock(&indio_dev->mlock);
>> +     if (iio_ring_enabled(indio_dev)) {
>> +             mutex_unlock(&indio_dev->mlock);
>> +             return -EBUSY;
>> +     }
>> +
>> +     switch (mask) {
>> +     case (1<<  IIO_CHAN_INFO_SCALE_SHARED):
>> +             ret = -EINVAL;
>> +             for (i = 0; i<  ARRAY_SIZE(st->scale_avail); i++)
>> +                     if (val2 == st->scale_avail[i][1]) {
>> +                             tmp = st->conf;
>> +                             st->conf&= ~AD7192_CONF_GAIN(-1);
>> +                             st->conf |= AD7192_CONF_GAIN(i);
>> +
>> +                             if (tmp != st->conf) {
>> +                                     ad7192_write_reg(st, AD7192_REG_CONF,
>> +                                                      3, st->conf);
>> +                                     ad7192_calibrate_all(st);
>> +                             }
>> +                             ret = 0;
>> +                     }
>> +
>> +     default:
>> +             ret = -EINVAL;
>> +     }
>> +
>> +     mutex_unlock(&indio_dev->mlock);
> blank line here.
>> +     return ret;
>> +}
>> +
>> +static int ad7192_validate_trigger(struct iio_dev *indio_dev,
>> +                                struct iio_trigger *trig)
>> +{
>> +     if (indio_dev->trig != trig)
>> +             return -EINVAL;
>> +
>> +     return 0;
>> +}
>> +
>> +static int ad7192_write_raw_get_fmt(struct iio_dev *indio_dev,
>> +                            struct iio_chan_spec const *chan,
>> +                            long mask)
>> +{
>> +     return IIO_VAL_INT_PLUS_NANO;
>> +}
>> +
>> +static const struct iio_info ad7192_info = {
>> +     .read_raw =&ad7192_read_raw,
>> +     .write_raw =&ad7192_write_raw,
>> +     .write_raw_get_fmt =&ad7192_write_raw_get_fmt,
>> +     .attrs =&ad7192_attribute_group,
>> +     .validate_trigger = ad7192_validate_trigger,
>> +     .driver_module = THIS_MODULE,
>> +};
>> +
>> +static struct iio_chan_spec ad7192_channels[] = {
>> +
> Peronsally I'm going more and more against this macro, so
> if you are bored, please define a local one setting up
> exactly those bits of the structure needed.  Its a little
> more code, but a heck of a lot more readable. (basically
> I was wrong to introduce this in the first place and will
> not be taking it out of staging if I can help it!)
>
ok
>> +     IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 1, 2,
>> +                 (1<<  IIO_CHAN_INFO_SCALE_SHARED),
>> +                 AD7192_CH_AIN1P_AIN2M,
>> +                 0, IIO_ST('s', 24, 32, 0), 0),
>> +     IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, NULL, 3, 4,
>> +                 (1<<  IIO_CHAN_INFO_SCALE_SHARED),
>> +                 AD7192_CH_AIN3P_AIN4M,
>> +                 1, IIO_ST('s', 24, 32, 0), 0),
>> +     IIO_CHAN(IIO_TEMP, 0, 1, 0, NULL, 0, 0,
>> +                 (1<<  IIO_CHAN_INFO_SCALE_SEPARATE),
>> +                 AD7192_CH_TEMP,
>> +                 2, IIO_ST('s', 24, 32, 0), 0),
>> +     IIO_CHAN(IIO_IN_DIFF, 0, 1, 0, "shorted", 2, 2,
>> +                 (1<<  IIO_CHAN_INFO_SCALE_SHARED),
>> +                 AD7192_CH_AIN2P_AIN2M,
>> +                 3, IIO_ST('s', 24, 32, 0), 0),
>> +     IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 1, 0,
>> +                 (1<<  IIO_CHAN_INFO_SCALE_SHARED),
>> +                 AD7192_CH_AIN1,
>> +                 4, IIO_ST('s', 24, 32, 0), 0),
>> +     IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 2, 0,
>> +                 (1<<  IIO_CHAN_INFO_SCALE_SHARED),
>> +                 AD7192_CH_AIN2,
>> +                 5, IIO_ST('s', 24, 32, 0), 0),
>> +     IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 3, 0,
>> +                 (1<<  IIO_CHAN_INFO_SCALE_SHARED),
>> +                 AD7192_CH_AIN3,
>> +                 6, IIO_ST('s', 24, 32, 0), 0),
>> +     IIO_CHAN(IIO_IN, 0, 1, 0, NULL, 4, 0,
>> +                 (1<<  IIO_CHAN_INFO_SCALE_SHARED),
>> +                 AD7192_CH_AIN4,
>> +                 7, IIO_ST('s', 24, 32, 0), 0),
>> +     IIO_CHAN_SOFT_TIMESTAMP(8),
>> +};
>> +
>> +static int __devinit ad7192_probe(struct spi_device *spi)
>> +{
>> +     struct ad7192_platform_data *pdata = spi->dev.platform_data;
>> +     struct ad7192_state *st;
>> +     struct iio_dev *indio_dev;
>> +     int ret, i , voltage_uv = 0, regdone = 0;
>> +
>> +     if (!pdata) {
>> +             dev_err(&spi->dev, "no platform data?\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     if (!spi->irq) {
>> +             dev_err(&spi->dev, "no IRQ?\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     indio_dev = iio_allocate_device(sizeof(*st));
>> +     if (indio_dev == NULL)
>> +             return -ENOMEM;
>> +
>> +     st = iio_priv(indio_dev);
>> +
>> +     st->reg = regulator_get(&spi->dev, "vcc");
>> +     if (!IS_ERR(st->reg)) {
>> +             ret = regulator_enable(st->reg);
>> +             if (ret)
>> +                     goto error_put_reg;
>> +
>> +             voltage_uv = regulator_get_voltage(st->reg);
>> +     }
>> +
>> +     st->pdata = pdata;
>> +
>> +     if (pdata&&  pdata->vref_mv)
>> +             st->int_vref_mv = pdata->vref_mv;
>> +     else if (voltage_uv)
>> +             st->int_vref_mv = voltage_uv / 1000;
>> +     else
>> +             dev_warn(&spi->dev, "reference voltage undefined\n");
>> +
>> +     spi_set_drvdata(spi, indio_dev);
>> +     st->spi = spi;
>> +     st->devid = spi_get_device_id(spi)->driver_data;
>> +     indio_dev->dev.parent =&spi->dev;
>> +     indio_dev->name = spi_get_device_id(spi)->name;
>> +     indio_dev->modes = INDIO_DIRECT_MODE;
>> +     indio_dev->channels = ad7192_channels;
>> +     indio_dev->num_channels = ARRAY_SIZE(ad7192_channels);
>> +     indio_dev->available_scan_masks = st->available_scan_masks;
>> +     indio_dev->info =&ad7192_info;
>> +
>> +     for (i = 0; i<  indio_dev->num_channels; i++)
>> +             st->available_scan_masks[i] = (1<<  i) | (1<<
>> +                     indio_dev->channels[indio_dev->num_channels - 1].
>> +                     scan_index);
>> +
>> +     init_waitqueue_head(&st->wq_data_avail);
>> +
>> +     ret = ad7192_register_ring_funcs_and_init(indio_dev);
>> +     if (ret)
>> +             goto error_disable_reg;
>> +
>> +     ret = iio_device_register(indio_dev);
>> +     if (ret)
>> +             goto error_unreg_ring;
>> +     regdone = 1;
> Hmm..
Anything bad here?
>> +
>> +     ret = ad7192_probe_trigger(indio_dev);
>> +     if (ret)
>> +             goto error_unreg_ring;
>> +
>> +     ret = iio_ring_buffer_register_ex(indio_dev->ring, 0,
>> +                                       indio_dev->channels,
>> +                                       indio_dev->num_channels);
>> +     if (ret)
>> +             goto error_remove_trigger;
>> +
>> +     ret = ad7192_setup(st);
>> +     if (ret)
>> +             goto error_uninitialize_ring;
>> +
>> +     return 0;
>> +
>> +error_uninitialize_ring:
>> +     iio_ring_buffer_unregister(indio_dev->ring);
>> +error_remove_trigger:
>> +     ad7192_remove_trigger(indio_dev);
>> +error_unreg_ring:
>> +     ad7192_ring_cleanup(indio_dev);
>> +error_disable_reg:
>> +     if (!IS_ERR(st->reg))
>> +             regulator_disable(st->reg);
>> +error_put_reg:
>> +     if (!IS_ERR(st->reg))
>> +             regulator_put(st->reg);
>> +
>> +     if (regdone)
>> +             iio_device_unregister(indio_dev);
>> +     else
>> +             iio_free_device(indio_dev);
>> +
>> +     return ret;
>> +}
>> +
>> +static int ad7192_remove(struct spi_device *spi)
>> +{
>> +     struct iio_dev *indio_dev = spi_get_drvdata(spi);
>> +     struct ad7192_state *st = iio_priv(indio_dev);
>> +
>> +     iio_ring_buffer_unregister(indio_dev->ring);
>> +     ad7192_remove_trigger(indio_dev);
>> +     ad7192_ring_cleanup(indio_dev);
>> +
>> +     if (!IS_ERR(st->reg)) {
>> +             regulator_disable(st->reg);
>> +             regulator_put(st->reg);
>> +     }
>> +
>> +     iio_device_unregister(indio_dev);
>> +
>> +     return 0;
>> +}
>> +
>> +static const struct spi_device_id ad7192_id[] = {
>> +     {"ad7190", ID_AD7190},
>> +     {"ad7192", ID_AD7192},
>> +     {"ad7195", ID_AD7195},
> tab in next line?
>> +{}
>> +};
>> +
>> +static struct spi_driver ad7192_driver = {
>> +     .driver = {
>> +             .name   = "ad7192",
>> +             .bus    =&spi_bus_type,
> This is set in spi_register_driver, so why set it here? (basically
> have I missed an upcoming change in the spi core?)
indeed needless
>> +             .owner  = THIS_MODULE,
>> +     },
>> +     .probe          = ad7192_probe,
>> +     .remove         = __devexit_p(ad7192_remove),
>> +     .id_table       = ad7192_id,
>> +};
>> +
>> +static int __init ad7192_init(void)
>> +{
>> +     return spi_register_driver(&ad7192_driver);
>> +}
>> +module_init(ad7192_init);
>> +
>> +static void __exit ad7192_exit(void)
>> +{
>> +     spi_unregister_driver(&ad7192_driver);
>> +}
>> +module_exit(ad7192_exit);
>> +
>> +MODULE_AUTHOR("Michael Hennerich<hennerich@blackfin.uclinux.org>");
>> +MODULE_DESCRIPTION("Analog Devices AD7190, AD7192, AD7195 ADC");
>> +MODULE_LICENSE("GPL v2");
>> diff --git a/drivers/staging/iio/adc/ad7192.h b/drivers/staging/iio/adc/ad7192.h
>> new file mode 100644
>> index 0000000..2e0bd5e
>> --- /dev/null
>> +++ b/drivers/staging/iio/adc/ad7192.h
>> @@ -0,0 +1,47 @@
>> +/*
>> + * AD7190 AD7192 AD7195 SPI ADC driver
>> + *
>> + * Copyright 2011 Analog Devices Inc.
>> + *
>> + * Licensed under the GPL-2.
>> + */
>> +#ifndef IIO_ADC_AD7192_H_
>> +#define IIO_ADC_AD7192_H_
>> +
>> +/*
>> + * TODO: struct ad7192_platform_data needs to go into include/linux/iio
>> + */
>> +
>> +/**
>> + * struct ad7192_platform_data - platform/board specific information
>> + * @vref_mv:         the external reference voltage in millivolt
>> + * @ext_clk_Hz:              the external clock frequency in Hz, if not set
>> + *                   the driver uses the internal clock (16.776 MHz)
>> + * @clock_source_sel:        [0..3]
>> + *                   0 External 4.92 MHz clock connected from MCLK1 to MCLK2
>> + *                   1 External Clock applied to MCLK2
>> + *                   2 Internal 4.92 MHz Clock not available at the MCLK2 pin
>> + *                   3 Internal 4.92 MHz Clock available at the MCLK2 pin
>> + * @refin2_en:               REFIN1/REFIN2 Reference Select (AD7190/2 only)
>> + * @rej60_en:                50/60Hz notch filter enable
>> + * @sinc3_en:                SINC3 filter enable (default SINC4)
>> + * @chop_en:         CHOP mode enable
>> + * @buf_en:          buffered input mode enable
>> + * @unipolar_en:     unipolar mode enable
>> + * @burnout_curr_en: constant current generators on AIN(+|-) enable
>> + */
>> +
>> +struct ad7192_platform_data {
>> +     u16             vref_mv;
>> +     u32             ext_clk_Hz;
> Trivial, but reorder this to the top to save 2 bytes.
ok
>> +     u8              clock_source_sel;
>> +     bool            refin2_en;
>> +     bool            rej60_en;
>> +     bool            sinc3_en;
>> +     bool            chop_en;
>> +     bool            buf_en;
>> +     bool            unipolar_en;
>> +     bool            burnout_curr_en;
>> +};
>> +
>> +#endif /* IIO_ADC_AD7192_H_ */
>

Thanks for the review!

-- 
Greetings,
Michael

--
Analog Devices GmbH      Wilhelm-Wagenfeld-Str. 6      80807 Muenchen
Sitz der Gesellschaft: Muenchen; Registergericht: Muenchen HRB 40368;
Geschaeftsfuehrer:Dr.Carsten Suckrow, Thomas Wessel, William A. Martin,
Margaret Seif

  reply	other threads:[~2011-08-17 13:47 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-12 12:41 [PATCH] IIO: ADC: New driver for AD7190/AD7192/AD7195 4 Channel SPI ADC michael.hennerich
2011-08-12 13:44 ` Jonathan Cameron
2011-08-17 13:47   ` Michael Hennerich [this message]
2011-08-17 14:29     ` Jonathan Cameron
  -- strict thread matches above, loose matches on Subject: below --
2011-08-17 15:04 michael.hennerich
2011-08-17 15:31 ` Jonathan Cameron
2011-08-17 15:57   ` Jonathan Cameron
2011-08-18  8:20     ` Hennerich, Michael
2011-08-17 16:05   ` Paul Thomas
2011-08-18  6:41     ` Hennerich, Michael
2011-08-18 17:26       ` Paul Thomas
2011-08-19  7:41         ` Hennerich, Michael
2011-08-26  6:41           ` Paul Thomas
2011-08-26  7:29             ` Hennerich, Michael
2011-08-17 15:29 michael.hennerich

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