Re: [PATCH V3]TAOS 258x: Device Driver

Jon Brenner
2011-03-28T18:51:07Z

HI Shubhrajyoti:
Thanks for taking time to review the code.
Please see my response to your comments throughout.

Jon

On Sat, 2011-03-26 at 22:47 +0530, Shubhrajyoti wrote:
> Hi Jon,
> Some minor comments.
>
> On Saturday 26 March 2011 03:11 AM, Jon Brenner wrote:
> > [PATCH v3] for TAOS tsl2580/81/83 Device driver
> >
> > Added suspend/resume functions.
> > Changed attribute names to match existing where applicable and updated or documented new ABI as discussed.
> > Changed integration time ABI from using index (0 to 3) to use actual gain values (1x,8x, etc.).
> > Removed various unused variables, declarations, and functions.
> > Revised code to accommodate different endianess (le16_to_cpu).
> > Updated error return codes in various functions.
> > Changed from mdelay to msleep after determining that longer wait would be acceptable.
> >
> > Signed-off-by:Jon August Brenner<jbrenner@taosinc.com>
> >
> > ---
> > drivers/staging/iio/Documentation/sysfs-bus-iio | 6 +
> > .../staging/iio/Documentation/sysfs-bus-iio-light | 13 +
> > .../iio/Documentation/sysfs-bus-iio-light-tsl2583 | 20 +
> > drivers/staging/iio/light/Kconfig | 9 +
> > drivers/staging/iio/light/Makefile | 1 +
> > drivers/staging/iio/light/tsl2583.c | 962 ++++++++++++++++++++
> > 6 files changed, 1011 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/staging/iio/Documentation/sysfs-bus-iio b/drivers/staging/iio/Documentation/sysfs-bus-iio
> > index 2dde97d..6a86ad2 100644
> > --- a/drivers/staging/iio/Documentation/sysfs-bus-iio
> > +++ b/drivers/staging/iio/Documentation/sysfs-bus-iio
> > @@ -6,6 +6,12 @@ Description:
> > Corresponds to a grouping of sensor channels. X is the IIO
> > index of the device.
> >
> > +What: /sys/bus/iio/devices/device[n]/power_state
> > +KernelVersion: 2.6.37
> > +Contact: linux-iio@vger.kernel.org
> > +Description:
> > + This property gets/sets the device power state.
> > +
> > What: /sys/bus/iio/devices/triggerX
> > KernelVersion: 2.6.35
> > Contact: linux-iio@vger.kernel.org
> > diff --git a/drivers/staging/iio/Documentation/sysfs-bus-iio-light b/drivers/staging/iio/Documentation/sysfs-bus-iio-light
> > index 5d84856..21d2774 100644
> > --- a/drivers/staging/iio/Documentation/sysfs-bus-iio-light
> > +++ b/drivers/staging/iio/Documentation/sysfs-bus-iio-light
> > @@ -62,3 +62,16 @@ Description:
> > sensing mode. This value should be the output from a reading
> > and if expressed in SI units, should include _input. If this
> > value is not in SI units, then it should include _raw.
> > +
> > +What: /sys/bus/iio/devices/device[n]/illuminance0_target
> > +KernelVersion: 2.6.37
> > +Contact: linux-iio@vger.kernel.org
> > +Description:
> > + This property gets/sets the last known external
> > + lux measurement used in/for calibration.
> > +
> > +What: /sys/bus/iio/devices/device[n]/illuminance0_integration_time
> > +KernelVersion: 2.6.37
> > +Contact: linux-iio@vger.kernel.org
> > +Description:
> > + This property gets/sets the sensors ADC analog integration time.
> > diff --git a/drivers/staging/iio/Documentation/sysfs-bus-iio-light-tsl2583 b/drivers/staging/iio/Documentation/sysfs-bus-iio-light-tsl2583
> > new file mode 100644
> > index 0000000..660781d
> > --- /dev/null
> > +++ b/drivers/staging/iio/Documentation/sysfs-bus-iio-light-tsl2583
> > @@ -0,0 +1,20 @@
> > +What: /sys/bus/iio/devices/device[n]/lux_table
> > +KernelVersion: 2.6.37
> > +Contact: linux-iio@vger.kernel.org
> > +Description:
> > + This property gets/sets the table of coefficients
> > + used in calculating illuminance in lux.
> > +
> > +What: /sys/bus/iio/devices/device[n]/illuminance0_calibrate
> > +KernelVersion: 2.6.37
> > +Contact: linux-iio@vger.kernel.org
> > +Description:
> > + This property causes an internal calibration of the als gain trim
> > + value which is later used in calculating illuminance in lux.
> > +
> > +What: /sys/bus/iio/devices/device[n]/illuminance0_input_target
> > +KernelVersion: 2.6.37
> > +Contact: linux-iio@vger.kernel.org
> > +Description:
> > + This property is the known externally illuminance (in lux).
> > + It is used in the process of calibrating the device accuracy.
> > diff --git a/drivers/staging/iio/light/Kconfig b/drivers/staging/iio/light/Kconfig
> > index 36d8bbe..55c146c 100644
> > --- a/drivers/staging/iio/light/Kconfig
> > +++ b/drivers/staging/iio/light/Kconfig
> > @@ -13,6 +13,15 @@ config SENSORS_TSL2563
> > This driver can also be built as a module. If so, the module
> > will be called tsl2563.
> >
> > +config TSL2583
> > + tristate "TAOS TSL2580, TSL2581, and TSL2583 light-to-digital converters"
> > + depends on I2C
> > + help
> > + Y = in kernel.
> > + M = as module.
> > + Provides support for the TAOS tsl2580, tsl2581, and tsl2583 devices.
> > + Access ALS data via iio, sysfs.
> > +
> > config SENSORS_ISL29018
> > tristate "ISL 29018 light and proximity sensor"
> > depends on I2C
> > diff --git a/drivers/staging/iio/light/Makefile b/drivers/staging/iio/light/Makefile
> > index 9142c0e..8a10815 100644
> > --- a/drivers/staging/iio/light/Makefile
> > +++ b/drivers/staging/iio/light/Makefile
> > @@ -3,4 +3,5 @@
> > #
> >
> > obj-$(CONFIG_SENSORS_TSL2563) += tsl2563.o
> > +obj-$(CONFIG_TSL2583) += tsl2583.o
> > obj-$(CONFIG_SENSORS_ISL29018) += isl29018.o
> > diff --git a/drivers/staging/iio/light/tsl2583.c b/drivers/staging/iio/light/tsl2583.c
> > new file mode 100644
> > index 0000000..013a742
> > --- /dev/null
> > +++ b/drivers/staging/iio/light/tsl2583.c
> > @@ -0,0 +1,962 @@
> > +/*
> > + * Device driver for monitoring ambient light intensity (lux)
> > + * within the TAOS tsl258x family of devices (tsl2580, tsl2581).
> > + *
> > + * Copyright (c) 2011, TAOS Corporation.
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License as published by
> > + * the Free Software Foundation; either version 2 of the License, or
> > + * (at your option) any later version.
> > + *
> > + * This program is distributed in the hope that it will be useful, but WITHOUT
> > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> > + * more details.
> > + *
> > + * You should have received a copy of the GNU General Public License along
> > + * with this program; if not, write to the Free Software Foundation, Inc.,
> > + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
> > + */
> > +
> > +#include<linux/kernel.h>
> > +#include<linux/i2c.h>
> > +#include<linux/errno.h>
> > +#include<linux/delay.h>
> > +#include<linux/string.h>
> > +#include<linux/mutex.h>
> > +#include<linux/unistd.h>
> > +#include "../iio.h"
> > +
> > +
> > +#define TSL258X_MAX_DEVICE_REGS 32
> > +
> > +/* Triton register offsets */
> > +#define TSL258X_REG_MAX 8
> > +
> > +/* Device Registers and Masks */
> > +#define TSL258X_CNTRL 0x00
> > +#define TSL258X_ALS_TIME 0X01
> > +#define TSL258X_INTERRUPT 0x02
> > +#define TSL258X_GAIN 0x07
> > +#define TSL258X_REVID 0x11
> > +#define TSL258X_CHIPID 0x12
> > +#define TSL258X_ALS_CHAN0LO 0x14
> > +#define TSL258X_ALS_CHAN0HI 0x15
> > +#define TSL258X_ALS_CHAN1LO 0x16
> > +#define TSL258X_ALS_CHAN1HI 0x17
> > +#define TSL258X_TMR_LO 0x18
> > +#define TSL258X_TMR_HI 0x19
> > +
> > +/* tsl2583 cmd reg masks */
> > +#define TSL258X_CMD_REG 0x80
> > +#define TSL258X_CMD_SPL_FN 0x60
> > +#define TSL258X_CMD_ALS_INT_CLR 0X01
> > +
> > +/* tsl2583 cntrl reg masks */
> > +#define TSL258X_CNTL_ADC_ENBL 0x02
> > +#define TSL258X_CNTL_PWR_ON 0x01
> > +
> > +/* tsl2583 status reg masks */
> > +#define TSL258X_STA_ADC_VALID 0x01
> > +#define TSL258X_STA_ADC_INTR 0x10
> > +
> > +/* Lux calculation constants */
> > +#define TSL258X_LUX_CALC_OVER_FLOW 65535
> > +
> > +enum {
> > + TSL258X_CHIP_UNKNOWN = 0,
> > + TSL258X_CHIP_WORKING = 1,
> > + TSL258X_CHIP_SUSPENDED = 2
> > +} TSL258X_CHIP_WORKING_STATUS;
> > +
> > +/* Per-device data */
> > +struct taos_als_info {
> > + u16 als_ch0;
> > + u16 als_ch1;
> > + u16 lux;
> > +};
> > +
> > +struct taos_settings {
> > + int als_time;
> > + int als_gain;
> > + int als_gain_trim;
> > + int als_cal_target;
> > +};
> > +
> > +struct tsl2583_chip {
> > + struct mutex als_mutex;
> > + struct i2c_client *client;
> > + struct iio_dev *iio_dev;
> > + struct taos_als_info als_cur_info;
> > + struct taos_settings taos_settings;
> > + int als_time_scale;
> > + int als_saturation;
> > + int taos_chip_status;
> > + u8 taos_config[8];
> > +};
> > +
> > +/*
> > + * Initial values for device - this values can/will be changed by driver.
> > + * and applications as needed.
> > + * These values are dynamic.
> > + */
> > +static const u8 taos_config[8] = {
> > + 0x00, 0xee, 0x00, 0x03, 0x00, 0xFF, 0xFF, 0x00
> > +}; /* cntrl atime intC Athl0 Athl1 Athh0 Athh1 gain */
> > +
> > +struct taos_lux {
> > + unsigned int ratio;
> > + unsigned int ch0;
> > + unsigned int ch1;
> > +};
> > +
> > +/* This structure is intentionally large to accommodate updates via sysfs. */
> > +/* Sized to 11 = max 10 segments + 1 termination segment */
> > +/* Assumption is is one and only one type of glass used */
> > +struct taos_lux taos_device_lux[11] = {
> > + { 9830, 8520, 15729 },
> > + { 12452, 10807, 23344 },
> > + { 14746, 6383, 11705 },
> > + { 17695, 4063, 6554 },
> > +};
> > +
> > +struct gainadj {
> > + s16 ch0;
> > + s16 ch1;
> > +};
> > +
> > +/* Index = (0 - 3) Used to validate the gain selection index */
> > +static const struct gainadj gainadj[] = {
> > + { 1, 1 },
> > + { 8, 8 },
> > + { 16, 16 },
> > + { 107, 115 }
> > +};
> > +
> > +/*
> > + * Provides initial operational parameter defaults.
> > + * These defaults may be changed through the device's sysfs files.
> > + */
> > +static void taos_defaults(struct tsl2583_chip *chip)
> > +{
> > + /* Operational parameters */
> > + chip->taos_settings.als_time = 450;
> > + /* must be a multiple of 50mS */
> > + chip->taos_settings.als_gain = 2;
> > + /* this is actually an index into the gain table */
> > + /* assume clear glass as default */
> > + chip->taos_settings.als_gain_trim = 1000;
> > + /* default gain trim to account for aperture effects */
> > + chip->taos_settings.als_cal_target = 130;
> > + /* Known external ALS reading used for calibration */
> > +}
> > +
> > +/*
> > + * Read a number of bytes starting at register (reg) location.
> > + * Return 0, or i2c_smbus_write_byte ERROR code.
> > + */
> Could we use i2c_smbus_read_block_data ?
NO -Many controllers no longer seem to support block mode read/write.
To use block mode reads could exclude some.

> > +static int
> > +taos_i2c_read(struct i2c_client *client, u8 reg, u8 *val, unsigned int len)
> > +{
> > + int ret;
> > + int i;
> > +
> > + for (i = 0; i< len; i++) {
> > + /* select register to write */
> > + ret = i2c_smbus_write_byte(client, (TSL258X_CMD_REG | reg));
> > + if (ret< 0) {
> > + dev_err(&client->dev, "taos_i2c_read failed to write"
> > + " register %x\n", reg);
> > + return ret;
> > + }
> > + /* read the data */
> > + *val = i2c_smbus_read_byte(client);
> > + val++;
> > + reg++;
> > + }
> > + return 0;
> > +}
> > +
> > +
> > +/*
> > + * Reads and calculates current lux value.
> > + * The raw ch0 and ch1 values of the ambient light sensed in the last
> > + * integration cycle are read from the device.
> > + * Time scale factor array values are adjusted based on the integration time.
> > + * The raw values are multiplied by a scale factor, and device gain is obtained
> > + * using gain index. Limit checks are done next, then the ratio of a multiple
> > + * of ch1 value, to the ch0 value, is calculated. The array taos_device_lux[]
> > + * declared above is then scanned to find the first ratio value that is just
> > + * above the ratio we just calculated. The ch0 and ch1 multiplier constants in
> > + * the array are then used along with the time scale factor array values, to
> > + * calculate the lux.
> > + */
> > +static int taos_get_lux(struct i2c_client *client)
> > +{
> > + u16 ch0, ch1; /* separated ch0/ch1 data from device */
> > + u32 lux; /* raw lux calculated from device data */
> > + u32 ratio;
> > + u8 buf[5];
> > + struct taos_lux *p;
> > + struct tsl2583_chip *chip = i2c_get_clientdata(client);
> > + int i, ret;
> > + u32 ch0lux = 0;
> > + u32 ch1lux = 0;
> > +
> > + if (mutex_trylock(&chip->als_mutex) == 0) {
> > + dev_info(&client->dev, "taos_get_lux device is busy\n");
> > + return chip->als_cur_info.lux; /* busy, so return LAST VALUE */
> > + }
> > +
> > + if (chip->taos_chip_status != TSL258X_CHIP_WORKING) {
> > + /* device is not enabled */
> > + dev_err(&client->dev, "taos_get_lux device is not enabled\n");
> > + ret = -EBUSY ;
> > + goto out_unlock;
> > + }
> > +
> > + ret = taos_i2c_read(client, (TSL258X_CMD_REG),&buf[0], 1);
> > + if (ret< 0) {
> > + dev_err(&client->dev, "taos_get_lux failed to read CMD_REG\n");
> > + goto out_unlock;
> > + }
> > + /* is data new& valid */
> > + if (!(buf[0]& TSL258X_STA_ADC_INTR)) {
> > + dev_err(&client->dev, "taos_get_lux data not valid\n");
> > + ret = chip->als_cur_info.lux; /* return LAST VALUE */
> > + goto out_unlock;
> > + }
> > +
> > + for (i = 0; i< 4; i++) {
> > + int reg = TSL258X_CMD_REG | (TSL258X_ALS_CHAN0LO + i);
> > + ret = taos_i2c_read(client, reg,&buf[i], 1);
> > + if (ret< 0) {
> > + dev_err(&client->dev, "taos_get_lux failed to read"
> > + " register %x\n", reg);
> > + goto out_unlock;
> > + }
> > + }
> > +
> > + /* clear status, really interrupt status (interrupts are off), but
> > + * we use the bit anyway - don't forget 0x80 - this is a command*/
> > + ret = i2c_smbus_write_byte(client,
> > + (TSL258X_CMD_REG | TSL258X_CMD_SPL_FN | TSL258X_CMD_ALS_INT_CLR));
> > +
> > + if (ret< 0) {
> > + dev_err(&client->dev,
> > + "taos_i2c_write_command failed in taos_get_lux, err = %d\n",
> > + ret);
> > + goto out_unlock; /* have no data, so return failure */
> > + }
> > +
> > + /* extract ALS/lux data */
> > + ch0 = le16_to_cpup((const __le16 *)&buf[0]);
> > + ch1 = le16_to_cpup((const __le16 *)&buf[2]);
> > +
> > + chip->als_cur_info.als_ch0 = ch0;
> > + chip->als_cur_info.als_ch1 = ch1;
> > +
> > + if ((ch0>= chip->als_saturation) || (ch1>= chip->als_saturation))
> > + goto return_max;
> > +
> > + if (ch0 == 0) {
> > + /* have no data, so return LAST VALUE */
> > + ret = chip->als_cur_info.lux = 0;
> > + goto out_unlock;
> > + }
> > + /* calculate ratio */
> > + ratio = (ch1<< 15) / ch0;
> > + /* convert to unscaled lux using the pointer to the table */
> > + for (p = (struct taos_lux *) taos_device_lux;
> > + p->ratio != 0&& p->ratio< ratio; p++)
> > + ;
> > +
> > + if (p->ratio == 0) {
> > + lux = 0;
> > + } else {
> > + ch0lux = ((ch0 * p->ch0) +
> > + (gainadj[chip->taos_settings.als_gain].ch0>> 1))
> > + / gainadj[chip->taos_settings.als_gain].ch0;
> > + ch1lux = ((ch1 * p->ch1) +
> > + (gainadj[chip->taos_settings.als_gain].ch1>> 1))
> > + / gainadj[chip->taos_settings.als_gain].ch1;
> > + lux = ch0lux - ch1lux;
> > + }
> > +
> > + /* note: lux is 31 bit max at this point */
> > + if (ch1lux> ch0lux) {
> > + dev_dbg(&client->dev, "No Data - Return last value\n");
> > + ret = chip->als_cur_info.lux = 0;
> > + goto out_unlock;
> > + }
> > +
> > + /* adjust for active time scale */
> > + if (chip->als_time_scale == 0)
> > + lux = 0;
> > + else
> > + lux = (lux + (chip->als_time_scale>> 1)) /
> > + chip->als_time_scale;
> > +
> > + /* adjust for active gain scale */
> > + lux>>= 13; /* tables have factor of 8192 builtin for accuracy */
> > + lux = (lux * chip->taos_settings.als_gain_trim + 500) / 1000;
> > + if (lux> TSL258X_LUX_CALC_OVER_FLOW) { /* check for overflow */
> > +return_max:
> > + lux = TSL258X_LUX_CALC_OVER_FLOW;
> > + }
> > +
> > + /* Update the structure with the latest VALID lux. */
> > + chip->als_cur_info.lux = lux;
> > + ret = lux;
> > +
> > +out_unlock:
> > + mutex_unlock(&chip->als_mutex);
> > + return ret;
> > +}
> > +
> > +/*
> > + * Obtain single reading and calculate the als_gain_trim (later used
> > + * to derive actual lux).
> > + * Return updated gain_trim value.
> > + */
> > +int taos_als_calibrate(struct i2c_client *client)
> > +{
> > + struct tsl2583_chip *chip = i2c_get_clientdata(client);
> > + u8 reg_val;
> > + unsigned int gain_trim_val;
> > + int ret;
> > + int lux_val;
> > +
> > + ret = i2c_smbus_write_byte(client, (TSL258X_CMD_REG | TSL258X_CNTRL));
> > + if (ret< 0) {
> > + dev_err(&client->dev,
> > + "taos_als_calibrate failed to reach the CNTRL register, ret=%d\n",
> > + ret);
> > + return ret;
> > + }
> > +
> > + reg_val = i2c_smbus_read_byte(client);
> > + if ((reg_val& (TSL258X_CNTL_ADC_ENBL | TSL258X_CNTL_PWR_ON))
> > + != (TSL258X_CNTL_ADC_ENBL | TSL258X_CNTL_PWR_ON)) {
> > + dev_err(&client->dev,
> > + "taos_als_calibrate failed: device not powered on with ADC enabled\n");
> > + return -1;
> > + }
> > +
> > + ret = i2c_smbus_write_byte(client, (TSL258X_CMD_REG | TSL258X_CNTRL));
> > + if (ret< 0) {
> > + dev_err(&client->dev,
> > + "taos_als_calibrate failed to reach the STATUS register, ret=%d\n",
> > + ret);
> > + return ret;
> > + }
> > + reg_val = i2c_smbus_read_byte(client);
> > +
> > + if ((reg_val& TSL258X_STA_ADC_VALID) != TSL258X_STA_ADC_VALID) {
> > + dev_err(&client->dev,
> > + "taos_als_calibrate failed: STATUS - ADC not valid.\n");
> > + return -ENODATA;
> > + }
> > + lux_val = taos_get_lux(client);
> > + if (lux_val< 0) {
> > + dev_err(&client->dev, "taos_als_calibrate failed to get lux\n");
> > + return lux_val;
> > + }
> > + gain_trim_val = (unsigned int) (((chip->taos_settings.als_cal_target)
> > + * chip->taos_settings.als_gain_trim) / lux_val);
> > +
> > + if ((gain_trim_val< 250) || (gain_trim_val> 4000)) {
> > + dev_err(&client->dev,
> > + "taos_als_calibrate failed: trim_val of %d is out of range\n",
> > + gain_trim_val);
> > + return -ENODATA;
> > + }
> > + chip->taos_settings.als_gain_trim = (int) gain_trim_val;
> > +
> > + return (int) gain_trim_val;
> > +}
> > +
> > +/*
> > + * Turn the device on.
> > + * Configuration must be set before calling this function.
> > + */
> > +static int taos_chip_on(struct i2c_client *client)
> > +{
> > + int i;
> > + int ret = 0;
> > + u8 *uP;
> > + u8 utmp;
> > + int als_count;
> > + int als_time;
> > + struct tsl2583_chip *chip = i2c_get_clientdata(client);
> > +
> > + /* and make sure we're not already on */
> > + if (chip->taos_chip_status == TSL258X_CHIP_WORKING) {
> > + /* if forcing a register update - turn off, then on */
> > + dev_info(&client->dev, "device is already enabled\n");
> > + return -EINVAL;
> > + }
> > +
> > + /* determine als integration regster */
> > + als_count = (chip->taos_settings.als_time * 100 + 135) / 270;
> > + if (als_count == 0)
> > + als_count = 1; /* ensure at least one cycle */
> > +
> > + /* convert back to time (encompasses overrides) */
> > + als_time = (als_count * 27 + 5) / 10;
> > + chip->taos_config[TSL258X_ALS_TIME] = 256 - als_count;
> > +
> > + /* Set the gain based on taos_settings struct */
> > + chip->taos_config[TSL258X_GAIN] = chip->taos_settings.als_gain;
> > +
> > + /* set chip struct re scaling and saturation */
> > + chip->als_saturation = als_count * 922; /* 90% of full scale */
> > + chip->als_time_scale = (als_time + 25) / 50;
> > +
> > + /* TSL258x Specific power-on / adc enable sequence
> > + * Power on the device 1st. */
> > + utmp = TSL258X_CNTL_PWR_ON;
> > + ret = i2c_smbus_write_byte_data(client, TSL258X_CMD_REG | TSL258X_CNTRL,
> > + utmp);
> > + if (ret< 0) {
> > + dev_err(&client->dev, "taos_chip_on failed on CNTRL reg.\n");
> > + return -1;
> > + }
> > +
> > + /* Use the following shadow copy for our delay before enabling ADC.
> > + * Write all the registers. */
> > + for (i = 0, uP = chip->taos_config; i< TSL258X_REG_MAX; i++) {
> > + ret = i2c_smbus_write_byte_data(client, TSL258X_CMD_REG + i,
> > + *uP++);
> > + if (ret< 0) {
> > + dev_err(&client->dev,
> > + "taos_chip_on failed on reg %d.\n", i);
> > + return -1;
> > + }
> > + }
> > +
> > + msleep(3);
> I think we could have a macro here.
What macro would you suggest?

> > + /* NOW enable the ADC
> > + * initialize the desired mode of operation */
> > + utmp = TSL258X_CNTL_PWR_ON | TSL258X_CNTL_ADC_ENBL;
> > + ret = i2c_smbus_write_byte_data(client, TSL258X_CMD_REG | TSL258X_CNTRL,
> > + utmp);
> > + if (ret< 0) {
> > + dev_err(&client->dev, "taos_chip_on failed on 2nd CTRL reg.\n");
> > + return -1;
> > + }
> > + chip->taos_chip_status = TSL258X_CHIP_WORKING;
> > +
> > + return ret;
> > +}
> > +
> > +static int taos_chip_off(struct i2c_client *client)
> > +{
> > + struct tsl2583_chip *chip = i2c_get_clientdata(client);
> > + int ret;
> > +
> > + /* turn device off */
> > + chip->taos_chip_status = TSL258X_CHIP_SUSPENDED;
> > + ret = i2c_smbus_write_byte_data(client, TSL258X_CMD_REG | TSL258X_CNTRL,
> > + 0x00);
> > + return ret;
> > +}
> > +
> > +/* Sysfs Interface Functions */
> > +static ssize_t taos_device_id(struct device *dev,
> > +struct device_attribute *attr, char *buf)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > +
> > + return sprintf(buf, "%s\n", chip->client->name);
> > +}
> > +
> > +static ssize_t taos_power_state_show(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > +
> > + return sprintf(buf, "%d\n", chip->taos_chip_status);
> > +}
> > +
> > +static ssize_t taos_power_state_store(struct device *dev,
> > + struct device_attribute *attr, const char *buf, size_t len)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > + unsigned long value;
> > +
> > + if (strict_strtoul(buf, 0,&value))
> > + return -EINVAL;
> > +
> > + if (value == 0)
> > + taos_chip_off(chip->client);
> > + else
> > + taos_chip_on(chip->client);
> > +
> > + return len;
> > +}
> > +
> > +static ssize_t taos_gain_show(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > + char gain[4] = {0};
> > +
> > + switch (chip->taos_settings.als_gain) {
> > + case 0:
> > + strcpy(gain, "001");
> > + break;
> > + case 1:
> > + strcpy(gain, "008");
> > + break;
> > + case 2:
> > + strcpy(gain, "016");
> > + break;
> > + case 3:
> > + strcpy(gain, "111");
> > + break;
> > + }
> > +
> > + return sprintf(buf, "%s\n", gain);
> > +}
> > +
> > +static ssize_t taos_gain_store(struct device *dev,
> > + struct device_attribute *attr, const char *buf, size_t len)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > + unsigned long value;
> > +
> > + if (strict_strtoul(buf, 0,&value))
> > + return -EINVAL;
> > +
> > + switch (value) {
> > + case 1:
> > + chip->taos_settings.als_gain = 0;
> > + break;
> > + case 8:
> > + chip->taos_settings.als_gain = 1;
> > + break;
> > + case 16:
> > + chip->taos_settings.als_gain = 2;
> > + break;
> > + case 111:
> > + chip->taos_settings.als_gain = 3;
> > + break;
> > + default:
> > + dev_err(dev, "Invalid Gain Index (must be 1,8,16,111)\n");
> > + return -1;
> > + }
> > +
> > + return len;
> > +}
> > +
> > +static ssize_t taos_gain_available_show(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + return sprintf(buf, "%s\n", "1 8 16 111");
> > +}
> > +
> > +static ssize_t taos_als_time_show(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > +
> > + return sprintf(buf, "%d\n", chip->taos_settings.als_time);
> > +}
> > +
> > +static ssize_t taos_als_time_store(struct device *dev,
> > + struct device_attribute *attr, const char *buf, size_t len)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > + unsigned long value;
> > +
> > + if (strict_strtoul(buf, 0,&value))
> > + return -EINVAL;
> > +
> > + if ((value< 50) || (value> 650))
> > + return -EINVAL;
> > +
> > + if (value % 50)
> > + return -EINVAL;
> > +
> > + chip->taos_settings.als_time = value;
> > +
> > + return len;
> > +}
> > +
> > +static ssize_t taos_als_time_available_show(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + return sprintf(buf, "%s\n",
> > + "50 100 150 200 250 300 350 400 450 500 550 600 650");
> > +}
> > +
> > +static ssize_t taos_als_trim_show(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > +
> > + return sprintf(buf, "%d\n", chip->taos_settings.als_gain_trim);
> > +}
> > +
> > +static ssize_t taos_als_trim_store(struct device *dev,
> > + struct device_attribute *attr, const char *buf, size_t len)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > + unsigned long value;
> > +
> > + if (strict_strtoul(buf, 0,&value))
> > + return -EINVAL;
> > +
> > + if (value)
> > + chip->taos_settings.als_gain_trim = value;
> > +
> > + return len;
> > +}
> > +
> > +static ssize_t taos_als_cal_target_show(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > +
> > + return sprintf(buf, "%d\n", chip->taos_settings.als_cal_target);
> > +}
> > +
> > +static ssize_t taos_als_cal_target_store(struct device *dev,
> > + struct device_attribute *attr, const char *buf, size_t len)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > + unsigned long value;
> > +
> > + if (strict_strtoul(buf, 0,&value))
> > + return -EINVAL;
> > +
> > + if (value)
> > + chip->taos_settings.als_cal_target = value;
> > +
> > + return len;
> > +}
> > +
> > +static ssize_t taos_lux_show(struct device *dev, struct device_attribute *attr,
> > + char *buf)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > + int lux;
> > +
> > + lux = taos_get_lux(chip->client);
> > +
> > + return sprintf(buf, "%d\n", lux);
> > +}
> > +
> > +static ssize_t taos_do_calibrate(struct device *dev,
> > + struct device_attribute *attr, const char *buf, size_t len)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > + unsigned long value;
> > +
> > + if (strict_strtoul(buf, 0,&value))
> > + return -EINVAL;
> > +
> > + if (value == 1)
> > + taos_als_calibrate(chip->client);
> > +
> > + return len;
> > +}
> > +
> > +static ssize_t taos_luxtable_show(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + int i;
> > + int offset = 0;
> > +
> > + for (i = 0; i< ARRAY_SIZE(taos_device_lux); i++) {
> > + offset += sprintf(buf + offset, "%d,%d,%d,",
> > + taos_device_lux[i].ratio,
> > + taos_device_lux[i].ch0,
> > + taos_device_lux[i].ch1);
> > + if (taos_device_lux[i].ratio == 0) {
> > + /* We just printed the first "0" entry.
> > + * Now get rid of the extra "," and break. */
> > + offset--;
> > + break;
> > + }
> > + }
> > +
> > + offset += sprintf(buf + offset, "\n");
> > + return offset;
> > +}
> > +
> > +static ssize_t taos_luxtable_store(struct device *dev,
> > + struct device_attribute *attr, const char *buf, size_t len)
> > +{
> > + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> > + struct tsl2583_chip *chip = indio_dev->dev_data;
> > + int value[ARRAY_SIZE(taos_device_lux)];
> > + int n;
> > +
> > + get_options(buf, ARRAY_SIZE(value), value);
> > +
> > + /* We now have an array of ints starting at value[1], and
> > + * enumerated by value[0].
> > + * We expect each group of three ints is one table entry,
> > + * and the last table entry is all 0.
> > + */
> > + n = value[0];
> > + if ((n % 3) || n< 6 || n> (ARRAY_SIZE(taos_device_lux) - 3)) {
> > + dev_info(dev, "LUX TABLE INPUT ERROR 1 Value[0]=%d\n", n);
> > + return -EINVAL;
> > + }
> > + if ((value[(n - 2)] | value[(n - 1)] | value[n]) != 0) {
> > + dev_info(dev, "LUX TABLE INPUT ERROR 2 Value[0]=%d\n", n);
> > + return -EINVAL;
> > + }
> > +
> > + if (chip->taos_chip_status == TSL258X_CHIP_WORKING)
> > + taos_chip_off(chip->client);
> > +
> > + /* Zero out the table */
> > + memset(taos_device_lux, 0, sizeof(taos_device_lux));
> > + memcpy(taos_device_lux,&value[1], (value[0] * 4));
> > +
> > + taos_chip_on(chip->client);
> > +
> > + return len;
> > +}
> > +
> > +static DEVICE_ATTR(name, S_IRUGO, taos_device_id, NULL);
> > +static DEVICE_ATTR(power_state, S_IRUGO | S_IWUSR,
> > + taos_power_state_show, taos_power_state_store);
> > +
> > +static DEVICE_ATTR(illuminance0_calibscale, S_IRUGO | S_IWUSR,
> > + taos_gain_show, taos_gain_store);
> > +static DEVICE_ATTR(illuminance0_calibscale_available, S_IRUGO,
> > + taos_gain_available_show, NULL);
> > +
> > +static DEVICE_ATTR(illuminance0_integration_time, S_IRUGO | S_IWUSR,
> > + taos_als_time_show, taos_als_time_store);
> > +static DEVICE_ATTR(illuminance0_integration_time_available, S_IRUGO,
> > + taos_als_time_available_show, NULL);
> > +
> > +static DEVICE_ATTR(illuminance0_calibbias, S_IRUGO | S_IWUSR,
> > + taos_als_trim_show, taos_als_trim_store);
> > +
> > +static DEVICE_ATTR(illuminance0_input_target, S_IRUGO | S_IWUSR,
> > + taos_als_cal_target_show, taos_als_cal_target_store);
> > +
> > +static DEVICE_ATTR(illuminance0_input, S_IRUGO, taos_lux_show, NULL);
> > +static DEVICE_ATTR(illuminance0_calibrate, S_IWUSR, NULL, taos_do_calibrate);
> > +static DEVICE_ATTR(illuminance0_lux_table, S_IRUGO | S_IWUSR,
> > + taos_luxtable_show, taos_luxtable_store);
> > +
> > +static struct attribute *sysfs_attrs_ctrl[] = {
> > + &dev_attr_name.attr,
> > + &dev_attr_power_state.attr,
> > + &dev_attr_illuminance0_calibscale.attr, /* Gain */
> > + &dev_attr_illuminance0_calibscale_available.attr,
> > + &dev_attr_illuminance0_integration_time.attr, /* I time*/
> > + &dev_attr_illuminance0_integration_time_available.attr,
> > + &dev_attr_illuminance0_calibbias.attr, /* trim */
> > + &dev_attr_illuminance0_input_target.attr,
> > + &dev_attr_illuminance0_input.attr,
> > + &dev_attr_illuminance0_calibrate.attr,
> > + &dev_attr_illuminance0_lux_table.attr,
> > + NULL
> > +};
> > +
> > +static struct attribute_group tsl2583_attribute_group = {
> > + .attrs = sysfs_attrs_ctrl,
> > +};
> > +
> > +/* Use the default register values to identify the Taos device */
> > +static int taos_tsl258x_device(unsigned char *bufp)
> > +{
> > + return ((bufp[TSL258X_CHIPID]& 0xf0) == 0x90);
> > +}
> > +
> > +/*
> > + * Client probe function - When a valid device is found, the driver's device
> > + * data structure is updated, and initialization completes successfully.
> > + */
> > +static int __devinit taos_probe(struct i2c_client *clientp,
> > + const struct i2c_device_id *idp)
> > +{
> > + int i, ret = 0;
> > + unsigned char buf[TSL258X_MAX_DEVICE_REGS];
> > + static struct tsl2583_chip *chip;
> > +
> > + if (!i2c_check_functionality(clientp->adapter,
> > + I2C_FUNC_SMBUS_BYTE_DATA)) {
> > + dev_err(&clientp->dev,
> > + "taos_probe() - i2c smbus byte data "
> > + "functions unsupported\n");
> > + return -EOPNOTSUPP;
> > + }
> > +
> > + chip = kzalloc(sizeof(struct tsl2583_chip), GFP_KERNEL);
> > + if (!chip)
> > + return -ENOMEM;
> > +
> > + chip->client = clientp;
> > + i2c_set_clientdata(clientp, chip);
> > +
> > + mutex_init(&chip->als_mutex);
> > + chip->taos_chip_status = TSL258X_CHIP_UNKNOWN;
> > + memcpy(chip->taos_config, taos_config, sizeof(chip->taos_config));
> > +
> > + for (i = 0; i< TSL258X_MAX_DEVICE_REGS; i++) {
> > + ret = i2c_smbus_write_byte(clientp,
> > + (TSL258X_CMD_REG | (TSL258X_CNTRL + i)));
> > + if (ret< 0) {
> > + dev_err(&clientp->dev, "i2c_smbus_write_bytes() to cmd "
> > + "reg failed in taos_probe(), err = %d\n", ret);
> > + goto fail1;
> > + }
> > + ret = i2c_smbus_read_byte(clientp);
> > + if (ret< 0) {
> > + dev_err(&clientp->dev, "i2c_smbus_read_byte from "
> > + "reg failed in taos_probe(), err = %d\n", ret);
> > +
> > + goto fail1;
> > + }
> > + buf[i] = ret;
> > + }
> > +
> > + if (!taos_tsl258x_device(buf)) {
> > + dev_info(&clientp->dev, "i2c device found but does not match "
> > + "expected id in taos_probe()\n");
> > + goto fail1;
> > + }
> > +
> > + ret = i2c_smbus_write_byte(clientp, (TSL258X_CMD_REG | TSL258X_CNTRL));
> > + if (ret< 0) {
> > + dev_err(&clientp->dev, "i2c_smbus_write_byte() to cmd reg "
> > + "failed in taos_probe(), err = %d\n", ret);
> > + goto fail1;
> > + }
> > +
> > + chip->iio_dev = iio_allocate_device();
> > + if (!chip->iio_dev) {
> > + ret = -ENOMEM;
> > + dev_err(&clientp->dev, "iio allocation failed\n");
> > + goto fail1;
> > + }
> > +
> > + chip->iio_dev->attrs =&tsl2583_attribute_group;
> > + chip->iio_dev->dev.parent =&clientp->dev;
> > + chip->iio_dev->dev_data = (void *)(chip);
> > + chip->iio_dev->driver_module = THIS_MODULE;
> > + chip->iio_dev->modes = INDIO_DIRECT_MODE;
> > + ret = iio_device_register(chip->iio_dev);
> > + if (ret) {
> > + dev_err(&clientp->dev, "iio registration failed\n");
> > + goto fail1;
> > + }
> > +
> > + /* Load up the V2 defaults (these are hard coded defaults for now) */
> > + taos_defaults(chip);
> > +
> > + /* Make sure the chip is on */
> > + taos_chip_on(clientp);
> > +
> > + dev_info(&clientp->dev, "Light sensor found.\n");
> > +
> > + return 0;
> > +
> > +fail1:
> > + kfree(chip);
> > +
> > + return ret;
> > +}
> > +
> > +static int taos_suspend(struct i2c_client *client, pm_message_t state)
> > +{
> > + struct tsl2583_chip *chip = i2c_get_clientdata(client);
> > + int ret = 0;
> > +
> > + mutex_lock(&chip->als_mutex);
> > +
> > + if (chip->taos_chip_status == TSL258X_CHIP_WORKING) {
> > + ret = taos_chip_off(client);
> > + chip->taos_chip_status = TSL258X_CHIP_SUSPENDED;
> > + }
> > +
> > + mutex_unlock(&chip->als_mutex);
> > + return ret;
> > +}
> > +
> > +static int taos_resume(struct i2c_client *client)
> > +{
> > + struct tsl2583_chip *chip = i2c_get_clientdata(client);
> > + int ret = 0;
> > +
> > + mutex_lock(&chip->als_mutex);
> > +
> > + if (chip->taos_chip_status == TSL258X_CHIP_SUSPENDED)
> > + ret = taos_chip_on(client);
> > +
> > + mutex_unlock(&chip->als_mutex);
> > + return ret;
> > +}
> > +
> > +
> > +static int __devexit taos_remove(struct i2c_client *client)
> > +{
> > + struct tsl2583_chip *chip = i2c_get_clientdata(client);
> > +
> > + iio_device_unregister(chip->iio_dev);
> > +
> > + kfree(chip);
> > + return 0;
> > +}
> > +
> > +static struct i2c_device_id taos_idtable[] = {
> > + { "tsl2580", 0 },
> > + { "tsl2581", 1 },
> > + { "tsl2583", 2 },
> > + {}
> > +};
> > +MODULE_DEVICE_TABLE(i2c, taos_idtable);
> > +
> > +/* Driver definition */
> > +static struct i2c_driver taos_driver = {
> > + .driver = {
> > + .name = "tsl2583",
> > + },
> > + .id_table = taos_idtable,
> > + .suspend = taos_suspend,
> > + .resume = taos_resume,
> > + .probe = taos_probe,
> > + .remove = __devexit_p(taos_remove),
> > +};
> > +
> > +static int __init taos_init(void)
> > +{
> > + return i2c_add_driver(&taos_driver);
> > +}
> > +
> > +static void __exit taos_exit(void)
> > +{
> > + i2c_del_driver(&taos_driver);
> > +}
> > +
> > +module_init(taos_init);
> > +module_exit(taos_exit);
> > +
> > +MODULE_AUTHOR("J. August Brenner<jbrenner@taosinc.com>");
> > +MODULE_DESCRIPTION("TAOS tsl2583 ambient light sensor driver");
> > +MODULE_LICENSE("GPL");
> > +
>