RE: [PATCH v1 2/2] mfd: twl6030-gpadc: TWL6030, TWL6032 GPADC driver
From: Kozaruk, Oleksandr
Date: Sat Jul 13 2013 - 06:33:26 EST
Hi Lee,
Thank you for the review. There is v3 of this patch. My bad I didn't put
it in reply to v1.
I'll address you comments in v4. Would you care to review v3, please.
Regards,
OK.
>> The GPADC is general purpose ADC found on TWL6030,
>> and TWL6032 PMIC, known also as Phoenix and PhoenixLite.
>>
>> The TWL6030 and TWL6032 have GPADC with 17 and 19
>> channels respectively. Some channels have current
>> source and are used for measuring voltage drop
>> on resistive load for detecting battery ID resistance,
>> or measuring voltage drop on NTC resistors for external
>> temperature measurements. Some channels measure voltage,
>> (i.e. battery voltage), and have voltage dividers,
>> thus, capable to scale voltage. Some channels are dedicated
>> for measuring die temperature.
>
>Can you use the full available width of the buffer please, either 72
>or 80 chars is normally fine.
>
>> Some channels are calibrated in 2 points, having
>> offsets from ideal values kept in trim registers. This
>> is used to correct measurements.
>>
>> The differences between GPADC in TWL6030 and TWL6032:
>> - 10 bit vs 12 bit ADC;
>> - 17 vs 19 channels;
>> - channels have different purpose(i. e. battery voltage
>
>Nit: No space here -^
>
>> channel 8 vs channel 18);
>> - trim values are interpreted differently.
>>
>> The driver exports function returning converted value for
>> requested channels.
>>
>> Based on the driver patched from Balaji TK, Graeme Gregory, Ambresh K,
>> Girish S Ghongdemath.
>>
>> Signed-off-by: Balaji T K <balajitk@xxxxxx>
>> Graeme Gregory <gg@xxxxxxxxxxxxxxx>
>
>SOB? RB? AB?
>
>> Signed-off-by: Oleksandr Kozaruk <oleksandr.kozaruk@xxxxxx>
>> ---
>> .../testing/sysfs-devices-platform-twl6030_gpadc | 5 +
>> drivers/mfd/Kconfig | 8 +
>> drivers/mfd/Makefile | 1 +
>> drivers/mfd/twl6030-gpadc.c | 1053 ++++++++++++++++++++
>> include/linux/i2c/twl6030-gpadc.h | 51 +
>
>Why here instead of include/linux/mfd?
>
>> 5 files changed, 1118 insertions(+)
>> create mode 100644 Documentation/ABI/testing/sysfs-devices-platform-twl6030_gpadc
>> create mode 100644 drivers/mfd/twl6030-gpadc.c
>> create mode 100644 include/linux/i2c/twl6030-gpadc.h
>>
>> diff --git a/Documentation/ABI/testing/sysfs-devices-platform-twl6030_gpadc b/Documentation/ABI/testing/sysfs-devices-platform-twl6030_gpadc
>> new file mode 100644
>> index 0000000..e9c5812
>> --- /dev/null
>> +++ b/Documentation/ABI/testing/sysfs-devices-platform-twl6030_gpadc
>> @@ -0,0 +1,5 @@
>> +What: /sys/bus/platform/devices/twl603X_gpadc.26/inX_channel
>
>Are you sure this is where they will be created?
>
>What's with the .26?
>
>> +Date: June 2013
>> +Contact: Oleksandr Kozaruk <oleksandr.kozaruk@xxxxxx>
>> +Description: Start GPADC conversion for chosen channel X and report the result.
>> + The result is returned in millivolts.
>
>Does this require Greg's Ack?
>
>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>> index d54e985..8eb7494 100644
>> --- a/drivers/mfd/Kconfig
>> +++ b/drivers/mfd/Kconfig
>> @@ -970,6 +970,14 @@ config MFD_TC3589X
>> additional drivers must be enabled in order to use the
>> functionality of the device.
>>
>> +config TWL6030_GPADC
>
>As this supports the TWL6030 and TWL6032, wouldn't it be better to use
>TWL603X. Same goes for the driver/header filenames.
>
>> + tristate "TWL6030 GPADC (General Purpose A/D Convertor) Support"
>> + depends on TWL4030_CORE
>> + default n
>> + help
>> + Say yes here if you want support for the TWL6030 General Purpose
>> + A/D Convertor.
>> +
>
>Any chance you can bundle this with the other TWL* variants instead of
>dumping it in an arbitrary location within the Kconfig file?
>
>> config MFD_TMIO
>> bool
>> default n
>> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
>> index 718e94a..59f504f 100644
>> --- a/drivers/mfd/Makefile
>> +++ b/drivers/mfd/Makefile
>> @@ -70,6 +70,7 @@ obj-$(CONFIG_MENELAUS) += menelaus.o
>> obj-$(CONFIG_TWL4030_CORE) += twl-core.o twl4030-irq.o twl6030-irq.o
>> obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o
>> obj-$(CONFIG_TWL4030_POWER) += twl4030-power.o
>> +obj-$(CONFIG_TWL6030_GPADC) += twl6030-gpadc.o
>> obj-$(CONFIG_MFD_TWL4030_AUDIO) += twl4030-audio.o
>> obj-$(CONFIG_TWL6040_CORE) += twl6040.o
>>
>> diff --git a/drivers/mfd/twl6030-gpadc.c b/drivers/mfd/twl6030-gpadc.c
>> new file mode 100644
>> index 0000000..1868bc0
>> --- /dev/null
>> +++ b/drivers/mfd/twl6030-gpadc.c
>> @@ -0,0 +1,1053 @@
>> +/*
>> + * TWL6030 GPADC module driver
>> + *
>> + * Copyright (C) 2009-2013 Texas Instruments Inc.
>> + * Nishant Kamat <nskamat@xxxxxx>
>> + * Balaji T K <balajitk@xxxxxx>
>> + * Graeme Gregory <gg@xxxxxxxxxxxxxxx>
>> + * Girish S Ghongdemath <girishsg@xxxxxx>
>> + * Ambresh K <ambresh@xxxxxx>
>> + * Oleksandr Kozaruk <oleksandr.kozaruk@xxxxxx
>> + *
>> + * Based on twl4030-madc.c
>> + * Copyright (C) 2008 Nokia Corporation
>> + * Mikko Ylinen <mikko.k.ylinen@xxxxxxxxx>
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License
>> + * version 2 as published by the Free Software Foundation.
>> + *
>> + * 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 St, Fifth Floor, Boston, MA
>> + * 02110-1301 USA
>> + *
>> + */
>> +#include <linux/init.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/kernel.h>
>> +#include <linux/types.h>
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/slab.h>
>> +#include <linux/hwmon-sysfs.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/i2c/twl.h>
>> +#include <linux/i2c/twl6030-gpadc.h>
>> +
>> +#define DRIVER_NAME "twl6030_gpadc"
>> +
>> +#define TWL6030_GPADC_MAX_CHANNELS 17
>> +#define TWL6032_GPADC_MAX_CHANNELS 19
>> +/* Define this as the biggest of all chips using this driver */
>> +#define GPADC_MAX_CHANNELS TWL6032_GPADC_MAX_CHANNELS
>> +
>> +#define TWL6030_GPADC_CTRL 0x00 /* 0x2e */
>> +#define TWL6030_GPADC_CTRL2 0x01 /* 0x2f */
>> +
>> +#define TWL6030_GPADC_RTSELECT_LSB 0x02 /* 0x30 */
>> +#define TWL6030_GPADC_RTSELECT_ISB 0x03
>> +#define TWL6030_GPADC_RTSELECT_MSB 0x04
>> +
>> +#define TWL6032_GPADC_RTSELECT_LSB 0x04 /* 0x32 */
>> +#define TWL6032_GPADC_RTSELECT_ISB 0x05
>> +#define TWL6032_GPADC_RTSELECT_MSB 0x06
>> +
>> +#define TWL6030_GPADC_CTRL_P1 0x05
>> +#define TWL6030_GPADC_CTRL_P2 0x06
>> +
>> +#define TWL6032_GPADC_GPSELECT_ISB 0x07
>> +#define TWL6032_GPADC_CTRL_P1 0x08
>> +
>> +#define TWL6032_GPADC_RTCH0_LSB 0x09
>> +#define TWL6032_GPADC_RTCH0_MSB 0x0a
>> +#define TWL6032_GPADC_RTCH1_LSB 0x0b
>> +#define TWL6032_GPADC_RTCH1_MSB 0x0c
>> +#define TWL6032_GPADC_GPCH0_LSB 0x0d
>> +#define TWL6032_GPADC_GPCH0_MSB 0x0e
>> +
>> +#define TWL6030_GPADC_CTRL_P1_SP1 BIT(3)
>> +#define TWL6030_GPADC_CTRL_P1_EOCRT BIT(2)
>> +#define TWL6030_GPADC_CTRL_P1_EOCP1 BIT(1)
>> +#define TWL6030_GPADC_CTRL_P1_BUSY BIT(0)
>> +
>> +#define TWL6030_GPADC_CTRL_P2_SP2 BIT(2)
>> +#define TWL6030_GPADC_CTRL_P2_EOCP2 BIT(1)
>> +#define TWL6030_GPADC_CTRL_P1_BUSY BIT(0)
>> +
>> +#define TWL6030_GPADC_EOC_SW BIT(1)
>> +#define TWL6030_GPADC_BUSY BIT(0)
>> +
>> +#define TWL6030_GPADC_RTCH0_LSB (0x07)
>> +#define TWL6030_GPADC_GPCH0_LSB (0x29)
>> +
>> +/* Fixed channels */
>> +#define TWL6030_GPADC_CTRL_TEMP1_EN BIT(0) /* input ch 1 */
>> +#define TWL6030_GPADC_CTRL_TEMP2_EN BIT(1) /* input ch 4 */
>> +#define TWL6030_GPADC_CTRL_SCALER_EN BIT(2) /* input ch 2 */
>> +#define TWL6030_GPADC_CTRL_SCALER_DIV4 BIT(3)
>> +#define TWL6030_GPADC_CTRL_SCALER_EN_CH11 BIT(4) /* input ch 11 */
>> +#define TWL6030_GPADC_CTRL_TEMP1_EN_MONITOR BIT(5)
>> +#define TWL6030_GPADC_CTRL_TEMP2_EN_MONITOR BIT(6)
>> +#define TWL6030_GPADC_CTRL_ISOURCE_EN BIT(7)
>> +
>> +#define TWL6030_GPADC_CTRL2_REMSENSE_0 BIT(0)
>> +#define TWL6030_GPADC_CTRL2_REMSENSE_1 BIT(1)
>> +#define TWL6030_GPADC_CTRL2_SCALER_EN_CH18 BIT(2)
>> +#define TWL6030_GPADC_CTRL2_VBAT_SCALER_DIV4 BIT(3)
>> +
>> +#define TWL6030_GPADC_RT_SW1_EOC_MASK BIT(5)
>> +#define TWL6030_GPADC_SW2_EOC_MASK BIT(6)
>> +
>> +#define TWL6032_GPADC_RT_EOC_MASK BIT(4)
>> +#define TWL6032_GPADC_SW_EOC_MASK BIT(5)
>> +
>> +#define TWL6030_GPADC_TRIM1 0xCD
>> +
>> +#define TWL6030_REG_TOGGLE1 0x90
>> +#define TWL6030_GPADCS BIT(1)
>> +#define TWL6030_GPADCR BIT(0)
>
>Any chance we can rid this lot into a header file somewhere?
>
>> +/**
>> + * struct twl6030_chnl_calib - channel calibration
>> + * @gain: slope coefficient for ideal curve
>> + * @gain_error: gain error
>> + * @offset_error: offset of the real curve
>> + */
>> +struct twl6030_chnl_calib {
>> + s32 gain;
>> + s32 gain_error;
>> + s32 offset_error;
>> +};
>> +
>> +/**
>> + * struct twl6030_ideal_code - GPADC calibration parameters
>> + * GPADC is calibrated in two points: at the beginning and
>> + * at the and of the measurable input range
>> + *
>> + * @code1: ideal code for the input at the beginning
>> + * @code2: ideal code for at the end of the range
>> + * @v1: voltage input at the beginning(low voltage)
>> + * @v2: voltage input at the end(high voltage)
>> + */
>> +struct twl6030_ideal_code {
>> + s16 code1;
>> + s16 code2;
>> + s16 v1;
>> + s16 v2;
>> +};
>
>The variable name choices used throughout this driver make it
>incredibly hard to read. Variable names like; d, x, v1, v2 etc are
>undecipherable when read in as function arguments, then used in some
>random equation. I'll provide examples later.
>
>Perhaps 'code' would be better read as '[raw|read|register]_value', if
>that's what it actually is. 'v' would be better understood if it was
>'voltage', or at least 'volt'. The '1' and '2' here should be replaced
>by 'start' and 'end' or similar too.
>
>> +struct twl6030_gpadc_data;
>> +
>> +/**
>> + * struct twl6030_gpadc_platform_data - platform specific data
>> + * @nchannels: number of GPADC channels
>> + * @twl6030_ideal: pointer to calibration parameters
>> + * @convert: pointer to ADC conversion function
>> + * @calibrate: pointer to calibration function
>> + */
>> +struct twl6030_gpadc_platform_data {
>> + const int nchannels;
>> + const struct twl6030_ideal_code *ideal;
>> + int (*convert)(u32 channels, struct twl6030_gpadc_result *res);
>> + int (*calibrate)(struct twl6030_gpadc_data *gpadc);
>> +};
>
>Is this actually platform data, or is it really device data?
>
>> +/**
>> + * struct twl6030_gpadc_data - GPADC data
>> + * @dev: device pointer
>> + * @lock: mutual exclusion lock for the structure
>> + * @irq_complete: completion to signal end of conversion
>> + * @twl6030_cal_tbl: pointer to calibration data for each
>> + * channel with gain error and offset
>> + * @pdata: pointer to device specific data
>
>... ah, so it's device data then? Calling it pdata, is misleading.
>
>> + */
>> +struct twl6030_gpadc_data {
>> + struct device *dev;
>> + struct mutex lock;
>> + struct completion irq_complete;
>> + struct twl6030_chnl_calib *twl6030_cal_tbl;
>> + const struct twl6030_gpadc_platform_data *pdata;
>> +};
>> +
>> +static struct twl6030_gpadc_data *the_gpadc;
>
>This doesn't need to be global - see below.
>
>> +/*
>> + * channels 11, 12, 13, 15 and 16 have no calibration data
>> + * calibration offset is same for channels 1, 3, 4, 5
>> + */
>> +static const struct twl6030_ideal_code
>> + twl6030_ideal[TWL6030_GPADC_MAX_CHANNELS] = {
>> + { /* ch 0, external, battery type, resistor value */
>> + .code1 = 116,
>> + .code2 = 745,
>> + .v1 = 141,
>> + .v2 = 910,
>> + },
>
>Care to elaborate on where these figures came from?
>
>> + { /* ch 1, external, battery temperature, NTC resistor value */
>> + .code1 = 82,
>> + .code2 = 900,
>> + .v1 = 100,
>> + .v2 = 1100,
>> + },
>> + { /* ch 2, external, audio accessory/general purpose */
>> + .code1 = 55,
>> + .code2 = 818,
>> + .v1 = 101,
>> + .v2 = 1499,
>> + },
>> + { /* ch 3, external, general purpose */
>> + .code1 = 82,
>> + .code2 = 900,
>> + .v1 = 100,
>> + .v2 = 1100,
>> + },
>> + { /* ch 4, external, temperature measurement/general purpose */
>> + .code1 = 82,
>> + .code2 = 900,
>> + .v1 = 100,
>> + .v2 = 1100,
>> + },
>> + { /* ch 5, external, general purpose */
>> + .code1 = 82,
>> + .code2 = 900,
>> + .v1 = 100,
>> + .v2 = 1100,
>> + },
>> + { /* ch 6, external, general purpose */
>> + .code1 = 82,
>> + .code2 = 900,
>> + .v1 = 100,
>> + .v2 = 1100,
>> + },
>> + { /* ch 7, internal, main battery */
>> + .code1 = 614,
>> + .code2 = 941,
>> + .v1 = 3001,
>> + .v2 = 4599,
>> + },
>> + { /* ch 8, internal, backup battery */
>> + .code1 = 82,
>> + .code2 = 688,
>> + .v1 = 501,
>> + .v2 = 4203,
>> + },
>> + { /* ch 9, internal, external charger input */
>> + .code1 = 182,
>> + .code2 = 818,
>> + .v1 = 2001,
>> + .v2 = 8996,
>> + },
>> + { /* ch 10, internal, VBUS */
>> + .code1 = 149,
>> + .code2 = 818,
>> + .v1 = 1001,
>> + .v2 = 5497,
>> + },
>> + {}, /* ch 11, internal, VBUS charging current */
>> + {}, /* ch 12, internal, Die temperature */
>> + {}, /* ch 13, internal, Die temperature */
>> + { /* ch 14, internal, USB ID line */
>> + .code1 = 48,
>> + .code2 = 714,
>> + .v1 = 323,
>> + .v2 = 4800,
>> + },
>> + {}, /* ch 15, internal, test network */
>> + {}, /* ch 16, internal, test network */
>> +};
>> +
>> +static const struct twl6030_ideal_code
>> + twl6032_ideal[TWL6032_GPADC_MAX_CHANNELS] = {
>> + { /* ch 0, external, battery type, resistor value */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 440,
>> + .v2 = 1000,
>> + },
>> + { /* ch 1, external, battery temperature, NTC resistor value */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 440,
>> + .v2 = 1000,
>> + },
>> + { /* ch 2, external, audio accessory/general purpose */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 660,
>> + .v2 = 1500,
>> + },
>> + { /* ch 3, external, temperature with external diode/general purpose */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 440,
>> + .v2 = 1000,
>> + },
>> + { /* ch 4, external, temperature measurement/general purpose */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 440,
>> + .v2 = 1000,
>> + },
>> + { /* ch 5, external, general purpose */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 440,
>> + .v2 = 1000,
>> + },
>> + { /* ch 6, external, general purpose */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 440,
>> + .v2 = 1000,
>> + },
>> + { /* ch7, internal, system supply */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 2200,
>> + .v2 = 5000,
>> + },
>> + { /* ch8, internal, backup battery */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 2200,
>> + .v2 = 5000,
>> + },
>> + { /* ch 9, internal, external charger input */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 3960,
>> + .v2 = 9000,
>> + },
>> + { /* ch10, internal, VBUS */
>> + .code1 = 150,
>> + .code2 = 751,
>> + .v1 = 1000,
>> + .v2 = 5000,
>> + },
>> + { /* ch 11, internal, VBUS DC-DC output current */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 660,
>> + .v2 = 1500,
>> + },
>> + { /* ch 12, internal, Die temperature */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 440,
>> + .v2 = 1000,
>> + },
>> + { /* ch 13, internal, Die temperature */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 440,
>> + .v2 = 1000,
>> + },
>> + { /* ch 14, internal, USB ID line */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 2420,
>> + .v2 = 5500,
>> + },
>> + {}, /* ch 15, internal, test network */
>> + {}, /* ch 16, internal, test network */
>> + {}, /* ch 17, internal, battery charging current */
>> + { /* ch 18, internal, battery voltage */
>> + .code1 = 1441,
>> + .code2 = 3276,
>> + .v1 = 2200,
>> + .v2 = 5000,
>> + },
>> +};
>> +
>> +static int twl6030_gpadc_read(struct twl6030_gpadc_data *gpadc, u8 reg)
>> +{
>> + int ret;
>> + u8 val = 0;
>> +
>> + ret = twl_i2c_read_u8(TWL6030_MODULE_GPADC, &val, reg);
>> + if (ret) {
>> + dev_dbg(gpadc->dev, "unable to read register 0x%X\n", reg);
>> + return ret;
>> + }
>> +
>> + return val;
>> +}
>> +
>> +static int twl6030_gpadc_write(u8 reg, u8 val)
>> +{
>> + return twl_i2c_write_u8(TWL6030_MODULE_GPADC, val, reg);
>> +}
>> +
>> +static int twl6030_gpadc_channel_raw_read(struct twl6030_gpadc_data *gpadc,
>> + u8 reg)
>> +{
>> + u8 msb, lsb;
>> +
>> + msb = twl6030_gpadc_read(gpadc, reg + 1);
>> + lsb = twl6030_gpadc_read(gpadc, reg);
>> +
>> + return (msb << 8) | lsb;
>> +}
>> +
>> +static int twl6030_gpadc_enable_irq(u8 mask)
>> +{
>> + int ret;
>> +
>> + ret = twl6030_interrupt_unmask(mask, REG_INT_MSK_LINE_B);
>> + ret |= twl6030_interrupt_unmask(mask, REG_INT_MSK_STS_B);
>> +
>> + return ret;
>> +}
>> +
>> +static void twl6030_gpadc_disable_irq(u8 mask)
>> +{
>> + twl6030_interrupt_mask(mask, REG_INT_MSK_LINE_B);
>> + twl6030_interrupt_mask(mask, REG_INT_MSK_STS_B);
>> +}
>> +
>> +static irqreturn_t twl6030_gpadc_irq_handler(int irq, void *_gpadc)
>> +{
>> + struct twl6030_gpadc_data *gpadc = _gpadc;
>> +
>> + complete(&gpadc->irq_complete);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int twl6030_channel_calibrated(const struct twl6030_gpadc_platform_data
>> + *pdata, int channel)
>> +{
>> + /* not calibrated channels have 0 in all structure members */
>> + return pdata->ideal[channel].code2;
>> +}
>> +
>> +static void twl6030_gpadc_read_channel(struct twl6030_gpadc_data *gpadc,
>> + int channel, u8 reg, struct twl6030_gpadc_result *res)
>> +{
>> + s32 raw_code;
>> + s32 corrected_code;
>> + int channel_value;
>> +
>> + raw_code = twl6030_gpadc_channel_raw_read(gpadc, reg);
>> +
>> + res->raw_code = raw_code;
>> +
>> + if (!twl6030_channel_calibrated(gpadc->pdata, channel)) {
>> + corrected_code = raw_code;
>> + channel_value = raw_code;
>> + } else {
>> + corrected_code = ((raw_code * 1000) -
>> + gpadc->twl6030_cal_tbl[channel].offset_error) /
>> + gpadc->twl6030_cal_tbl[channel].gain_error;
>
>Can you add a small comment to describe what you're doing here?
>
>> +
>> + channel_value = corrected_code *
>> + gpadc->twl6030_cal_tbl[channel].gain;
>
>... and here.
>
>> + /* Shift back into mV range */
>> + channel_value /= 1000;
>> + }
>> +
>> + dev_dbg(gpadc->dev, "GPADC raw: %d", raw_code);
>> + dev_dbg(gpadc->dev, "GPADC cor: %d", corrected_code);
>> + dev_dbg(gpadc->dev, "GPADC val: %d", channel_value);
>
>Odd that the debug prints are _less_ verbose than the variable names.
>
>> + res->corrected_code = corrected_code;
>> + res->result = channel_value;
>> +}
>> +
>> +static void twl6030_gpadc_get_results(u8 reg, u32 channels,
>> + struct twl6030_gpadc_result *res)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < TWL6030_GPADC_MAX_CHANNELS; i++) {
>> +
>> + if (!(channels & BIT(i)))
>> + continue;
>> +
>> + reg += 2 * i;
>> + twl6030_gpadc_read_channel(the_gpadc, i, reg, &res[i]);
>> + }
>> +}
>> +
>> +/* locks held by caller */
>> +static int _twl6030_gpadc_conversion(u32 channels,
>> + struct twl6030_gpadc_result *res)
>> +{
>> + int ret;
>> +
>> + /* start conversion */
>> + ret = twl6030_gpadc_write(TWL6030_GPADC_CTRL_P1,
>> + TWL6030_GPADC_CTRL_P1_SP1);
>> + if (ret) {
>> + pr_err("%s: failed to write\n", __func__);
>> + return ret;
>> + }
>> +
>> + /* wait for conversion to complete */
>> + wait_for_completion_interruptible_timeout(&the_gpadc->irq_complete,
>> + msecs_to_jiffies(5000));
>> +
>> + /* get the results */
>> + twl6030_gpadc_get_results(TWL6030_GPADC_GPCH0_LSB, channels, res);
>> +
>> + return ret;
>> +}
>
>Why do the two *_gpadc_conversion() functions vastly differ semantically?
>
>> +/* locks held by caller */
>> +static int _twl6032_gpadc_conversion(u32 channels,
>> + struct twl6030_gpadc_result *res)
>> +{
>> + int i;
>> + int ret;
>> +
>> + for (i = 0; i < TWL6032_GPADC_MAX_CHANNELS; i++) {
>> + if (!(channels & BIT(i)))
>> + continue;
>> +
>> + /* select the ADC channel to read */
>> + ret = twl6030_gpadc_write(TWL6032_GPADC_GPSELECT_ISB, i);
>> + if (ret)
>> + goto out;
>> +
>> + /* start conversion */
>> + ret = twl6030_gpadc_write(TWL6032_GPADC_CTRL_P1,
>> + TWL6030_GPADC_CTRL_P1_SP1);
>> + if (ret)
>> + goto out;
>> +
>> + /* wait for conversion to complete */
>> + wait_for_completion_interruptible_timeout(
>> + &the_gpadc->irq_complete, msecs_to_jiffies(5000));
>> +
>> + twl6030_gpadc_read_channel(the_gpadc, i,
>> + TWL6032_GPADC_GPCH0_LSB, &res[i]);
>> + }
>> +
>> + return ret;
>> +out:
>> + pr_err("%s: failed to write\n", __func__);
>> + return ret;
>> +}
>> +
>> +int twl6030_gpadc_conversion(u32 channels, struct twl6030_gpadc_result *buf)
>> +{
>> + struct twl6030_gpadc_data *gpadc = the_gpadc;
>> + int ret;
>> +
>> + if (!gpadc)
>> + return -EAGAIN;
>
>Why EAGAIN? Will 'the_gpadc' appear _later_?
>
>> + mutex_lock(&gpadc->lock);
>> +
>> + ret = gpadc->pdata->convert(channels, buf);
>> +
>> + mutex_unlock(&the_gpadc->lock);
>> +
>> + return ret;
>> +}
>> +EXPORT_SYMBOL(twl6030_gpadc_conversion);
>> +
>> +static ssize_t show_channel(struct device *dev,
>> + struct device_attribute *devattr, char *buf)
>> +{
>> + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
>> + struct twl6030_gpadc_result res[GPADC_MAX_CHANNELS];
>> + u32 channel = (1 << attr->index);
>
>Can we use BIT() again for the sake of consistency?
>
>> + int ret;
>> +
>> + ret = twl6030_gpadc_conversion(channel, res);
>> + if (ret)
>> + return ret;
>> +
>> + return sprintf(buf, "%d\n", res[attr->index].result);
>> +}
>> +
>> +#define in_channel(index) \
>> +static SENSOR_DEVICE_ATTR(in##index##_channel, S_IRUGO, show_channel, \
>> + NULL, index);
>> +
>> +in_channel(0);
>> +in_channel(1);
>> +in_channel(2);
>> +in_channel(3);
>> +in_channel(4);
>> +in_channel(5);
>> +in_channel(6);
>> +in_channel(7);
>> +in_channel(8);
>> +in_channel(9);
>> +in_channel(10);
>> +in_channel(11);
>> +in_channel(12);
>> +in_channel(13);
>> +in_channel(14);
>> +in_channel(15);
>> +in_channel(16);
>> +in_channel(17);
>> +in_channel(18);
>> +
>> +#define IN_ATTRS_CHANNEL(X) (&sensor_dev_attr_in##X##_channel.dev_attr.attr)
>> +
>> +/*
>> + * the number of attributes is chosen as for a device with
>> + * max number of channels. It will be truncated before sysfs entries
>> + * are created on probe.
>> + */
>> +static struct attribute *twl6030_gpadc_attributes[] = {
>> + IN_ATTRS_CHANNEL(0),
>> + IN_ATTRS_CHANNEL(1),
>> + IN_ATTRS_CHANNEL(2),
>> + IN_ATTRS_CHANNEL(3),
>> + IN_ATTRS_CHANNEL(4),
>> + IN_ATTRS_CHANNEL(5),
>> + IN_ATTRS_CHANNEL(6),
>> + IN_ATTRS_CHANNEL(7),
>> + IN_ATTRS_CHANNEL(8),
>> + IN_ATTRS_CHANNEL(9),
>> + IN_ATTRS_CHANNEL(10),
>> + IN_ATTRS_CHANNEL(11),
>> + IN_ATTRS_CHANNEL(12),
>> + IN_ATTRS_CHANNEL(13),
>> + IN_ATTRS_CHANNEL(14),
>> + IN_ATTRS_CHANNEL(15),
>> + IN_ATTRS_CHANNEL(16),
>> + IN_ATTRS_CHANNEL(17),
>> + IN_ATTRS_CHANNEL(18),
>> + NULL
>> +};
>> +
>> +static const struct attribute_group twl6030_gpadc_group = {
>> + .attrs = twl6030_gpadc_attributes,
>> +};
>> +
>> +static void twl6030_calibrate_channel(struct twl6030_gpadc_data *gpadc,
>> + int channel, int d1, int d2)
>> +{
>> + int b, k, gain, x1, x2;
>> + const struct twl6030_ideal_code *ideal = gpadc->pdata->ideal;
>> +
>> + /* Gain */
>> + gain = ((ideal[channel].v2 - ideal[channel].v1) * 1000) /
>> + (ideal[channel].code2 - ideal[channel].code1);
>> +
>> + x1 = ideal[channel].code1;
>> + x2 = ideal[channel].code2;
>> +
>> + /* k */
>> + k = 1000 + (((d2 - d1) * 1000) / (x2 - x1));
>> +
>> + /* b */
>> + b = (d1 * 1000) - (k - 1000) * x1;
>
>This function is pure craziness. A viewer should be able to decipher
>what a function is doing without tracing back the source of each
>variable. Better variable naming conventions and/or more verbose
>commenting is required here. The equations also need better (or at
>least some) explanation.
>
>> + gpadc->twl6030_cal_tbl[channel].gain = gain;
>> + gpadc->twl6030_cal_tbl[channel].gain_error = k;
>> + gpadc->twl6030_cal_tbl[channel].offset_error = b;
>> +
>> + dev_dbg(gpadc->dev, "GPADC d1 for Chn: %d = %d\n", channel, d1);
>> + dev_dbg(gpadc->dev, "GPADC d2 for Chn: %d = %d\n", channel, d2);
>> + dev_dbg(gpadc->dev, "GPADC x1 for Chn: %d = %d\n", channel, x1);
>> + dev_dbg(gpadc->dev, "GPADC x2 for Chn: %d = %d\n", channel, x2);
>> + dev_dbg(gpadc->dev, "GPADC Gain for Chn: %d = %d\n", channel, gain);
>> + dev_dbg(gpadc->dev, "GPADC k for Chn: %d = %d\n", channel, k);
>> + dev_dbg(gpadc->dev, "GPADC b for Chn: %d = %d\n", channel, b);
>> +}
>> +
>> +static inline int twl6030_gpadc_get_trim_offset(s8 d)
>> +{
>> + int sign;
>> +
>> + /*
>> + * XXX NOTE!
>> + * bit 0 - sign, bit 7 - reserved, 6..1 - trim value
>> + * though, the documentation states that trim value
>> + * is absolute value, the correct conversion results are
>> + * obtained if the value is interpreted as 2's complement.
>> + */
>> + sign = d & 1;
>> + d = (d & 0x7f) >> 1;
>> +
>> + return sign ? (d | 0xc0) : d;
>> +}
>> +
>> +static int twl6030_calibration(struct twl6030_gpadc_data *gpadc)
>> +{
>> + int ret;
>> + int chn;
>> + u8 trim_regs[TWL6030_GPADC_MAX_CHANNELS];
>> + s8 d1, d2;
>> +
>> + /*
>> + * for calibration two measurements have been performed at
>> + * factory, for some channels, during the production test and
>> + * have been stored in registers. This two stored values are
>> + * used to correct the measurements. The values represent
>> + * offsets for the given input from the output on ideal curve.
>> + */
>> + ret = twl_i2c_read(TWL6030_MODULE_ID2, trim_regs,
>> + TWL6030_GPADC_TRIM1, 16);
>> + if (ret < 0)
>> + return ret;
>> +
>> + for (chn = 0; chn < TWL6030_GPADC_MAX_CHANNELS; chn++) {
>> +
>> + switch (chn) {
>> + case 0:
>> + d1 = trim_regs[0];
>> + d2 = trim_regs[1];
>> + break;
>> + case 1:
>> + d1 = trim_regs[4];
>> + d2 = trim_regs[5];
>> + break;
>> + case 2:
>> + d1 = trim_regs[12];
>> + d2 = trim_regs[13];
>> + break;
>> + case 3:
>> + case 4:
>> + case 5:
>> + case 6:
>> + d1 = trim_regs[4];
>> + d2 = trim_regs[5];
>> + break;
>> + case 7:
>> + d1 = trim_regs[6];
>> + d2 = trim_regs[7];
>> + break;
>> + case 8:
>> + d1 = trim_regs[2];
>> + d2 = trim_regs[3];
>> + break;
>> + case 9:
>> + d1 = trim_regs[8];
>> + d2 = trim_regs[9];
>> + break;
>> + case 10:
>> + d1 = trim_regs[10];
>> + d2 = trim_regs[11];
>> + break;
>> + case 14:
>> + d1 = trim_regs[14];
>> + d2 = trim_regs[15];
>> + break;
>> + default:
>> + continue;
>> + }
>> +
>> + d1 = twl6030_gpadc_get_trim_offset(d1);
>> + d2 = twl6030_gpadc_get_trim_offset(d2);
>> +
>> + twl6030_calibrate_channel(gpadc, chn, d1, d2);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int twl6032_calibration(struct twl6030_gpadc_data *gpadc)
>> +{
>> + int chn, d1 = 0, d2 = 0, temp;
>> + u8 trim_regs[17];
>> + int ret;
>> +
>> + ret = twl_i2c_read(TWL6030_MODULE_ID2, trim_regs + 1,
>> + TWL6030_GPADC_TRIM1, 16);
>> + if (ret < 0)
>> + return ret;
>> +
>> + /* Loop to calculate the value needed for returning voltages from
>> + * GPADC not values.
>> + *
>> + * gain is calculated to 3 decimal places fixed point.
>> + */
>
>Please read:
>
>"The preferred style for long (multi-line) comments is:"
>
>in Documentation/CodingStyle.
>
>> + for (chn = 0; chn < TWL6032_GPADC_MAX_CHANNELS; chn++) {
>> +
>> + switch (chn) {
>> + case 0:
>> + case 1:
>> + case 2:
>> + case 3:
>> + case 4:
>> + case 5:
>> + case 6:
>> + case 11:
>> + case 12:
>> + case 13:
>> + case 14:
>> + /* D1 */
>> + d1 = (trim_regs[3] & 0x1F) << 2;
>> + d1 |= (trim_regs[1] & 0x06) >> 1;
>> + if (trim_regs[1] & 0x01)
>> + d1 = -d1;
>> +
>> + /* D2 */
>> + d2 = (trim_regs[4] & 0x3F) << 2;
>> + d2 |= (trim_regs[2] & 0x06) >> 1;
>> + if (trim_regs[2] & 0x01)
>> + d2 = -d2;
>> + break;
>> + case 8:
>> + /* D1 */
>> + temp = (trim_regs[3] & 0x1F) << 2;
>> + temp |= (trim_regs[1] & 0x06) >> 1;
>> + if (trim_regs[1] & 0x01)
>> + temp = -temp;
>> +
>> + d1 = (trim_regs[8] & 0x18) << 1;
>> + d1 |= (trim_regs[7] & 0x1E) >> 1;
>> + if (trim_regs[7] & 0x01)
>> + d1 = -d1;
>> +
>> + d1 += temp;
>> +
>> + /* D2 */
>> + temp = (trim_regs[4] & 0x3F) << 2;
>> + temp |= (trim_regs[2] & 0x06) >> 1;
>> + if (trim_regs[2] & 0x01)
>> + temp = -temp;
>> +
>> + d2 = (trim_regs[10] & 0x1F) << 2;
>> + d2 |= (trim_regs[8] & 0x06) >> 1;
>> + if (trim_regs[8] & 0x01)
>> + d2 = -d2;
>> +
>> + d2 += temp;
>> + break;
>> + case 9:
>> + /* D1 */
>> + temp = (trim_regs[3] & 0x1F) << 2;
>> + temp |= (trim_regs[1] & 0x06) >> 1;
>> + if (trim_regs[1] & 0x01)
>> + temp = -temp;
>> +
>> + d1 = (trim_regs[14] & 0x18) << 1;
>> + d1 |= (trim_regs[12] & 0x1E) >> 1;
>> + if (trim_regs[12] & 0x01)
>> + d1 = -d1;
>> +
>> + d1 += temp;
>> +
>> + /* D2 */
>> + temp = (trim_regs[4] & 0x3F) << 2;
>> + temp |= (trim_regs[2] & 0x06) >> 1;
>> + if (trim_regs[2] & 0x01)
>> + temp = -temp;
>> +
>> + d2 = (trim_regs[16] & 0x1F) << 2;
>> + d2 |= (trim_regs[14] & 0x06) >> 1;
>> + if (trim_regs[14] & 0x01)
>> + d2 = -d2;
>> +
>> + d2 += temp;
>> + case 10:
>> + /* D1 */
>> + d1 = (trim_regs[11] & 0x0F) << 3;
>> + d1 |= (trim_regs[9] & 0x0E) >> 1;
>> + if (trim_regs[9] & 0x01)
>> + d1 = -d1;
>> +
>> + /* D2 */
>> + d2 = (trim_regs[15] & 0x0F) << 3;
>> + d2 |= (trim_regs[13] & 0x0E) >> 1;
>> + if (trim_regs[13] & 0x01)
>> + d2 = -d2;
>> + break;
>> + case 7:
>> + case 18:
>> + /* D1 */
>> + temp = (trim_regs[3] & 0x1F) << 2;
>> + temp |= (trim_regs[1] & 0x06) >> 1;
>> + if (trim_regs[1] & 0x01)
>> + temp = -temp;
>> +
>> + d1 = (trim_regs[5] & 0x7E) >> 1;
>> + if (trim_regs[5] & 0x01)
>> + d1 = -d1;
>> +
>> + d1 += temp;
>> +
>> + /* D2 */
>> + temp = (trim_regs[4] & 0x3F) << 2;
>> + temp |= (trim_regs[2] & 0x06) >> 1;
>> + if (trim_regs[2] & 0x01)
>> + temp = -temp;
>> +
>> + d2 = (trim_regs[6] & 0xFE) >> 1;
>> + if (trim_regs[6] & 0x01)
>> + d2 = -d2;
>> +
>> + d2 += temp;
>> + break;
>
>I think more explanation surrounding the equation(s) is required.
>
>> + default:
>> + /* No data for other channels */
>> + continue;
>> + }
>> +
>> + twl6030_calibrate_channel(gpadc, chn, d1, d2);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static const struct twl6030_gpadc_platform_data twl6030_pdata = {
>> + .nchannels = TWL6030_GPADC_MAX_CHANNELS,
>> + .ideal = twl6030_ideal,
>> + .convert = _twl6030_gpadc_conversion,
>> + .calibrate = twl6030_calibration,
>> +};
>> +
>> +static const struct twl6030_gpadc_platform_data twl6032_pdata = {
>> + .nchannels = TWL6032_GPADC_MAX_CHANNELS,
>> + .ideal = twl6032_ideal,
>> + .convert = _twl6032_gpadc_conversion,
>> + .calibrate = twl6032_calibration,
>> +};
>> +
>> +static struct of_device_id of_twl6030_match_tbl[] = {
>> + {
>> + .compatible = "ti,twl6030_gpadc",
>> + .data = &twl6030_pdata,
>> + },
>> + {
>> + .compatible = "ti,twl6032_gpadc",
>> + .data = &twl6032_pdata,
>> + },
>> + { /* end */ }
>> +};
>> +
>> +static int twl6030_gpadc_probe(struct platform_device *pdev)
>> +{
>> + struct device *dev = &pdev->dev;
>> + struct twl6030_gpadc_data *gpadc;
>> + const struct twl6030_gpadc_platform_data *pdata;
>> + const struct of_device_id *match;
>> + int irq;
>> + int ret = 0;
>
>There's no requirement to initialise ret here.
>
>> + match = of_match_device(of_match_ptr(of_twl6030_match_tbl), dev);
>> + pdata = match ? match->data : dev->platform_data;
>
>The twl6040 just went DT only. Is this the case for the twl6030x too?
>
>If so, can you remove pdata support.
>
>
>> + if (!pdata)
>> + return -EINVAL;
>> +
>> + gpadc = devm_kzalloc(dev, sizeof(struct twl6030_gpadc_data),
>> + GFP_KERNEL);
>> + if (!gpadc)
>> + return -ENOMEM;
>> +
>> + gpadc->twl6030_cal_tbl = devm_kzalloc(dev,
>> + sizeof(struct twl6030_chnl_calib) *
>> + pdata->nchannels, GFP_KERNEL);
>> + if (!gpadc->twl6030_cal_tbl)
>> + return -ENOMEM;
>> +
>> + the_gpadc = gpadc;
>
>What's the point in this? Why not use 'the_gpadc' immediately?
>
>> + gpadc->dev = dev;
>> + gpadc->pdata = pdata;
>> +
>> + platform_set_drvdata(pdev, gpadc);
>
>So you've made 'the_gpadc' global to maintain access to your core
>information, then set it as drvdata in any case? Why not remove the
>needlessly global and weirdly named 'the_gpadc' and use
>platform_get_drvdata to fetch the information when you require it?
>
>> + mutex_init(&gpadc->lock);
>> + init_completion(&gpadc->irq_complete);
>> +
>> + ret = pdata->calibrate(gpadc);
>> + if (ret < 0) {
>> + dev_err(&pdev->dev, "Failed to read calibration registers\n");
>> + return ret;
>> + }
>> +
>> + irq = platform_get_irq(pdev, 0);
>> + if (irq < 0) {
>> + dev_err(&pdev->dev, "failed to get irq\n");
>> + return ret;
>> + }
>> +
>> + ret = devm_request_threaded_irq(dev, irq, NULL,
>> + twl6030_gpadc_irq_handler,
>> + IRQF_ONESHOT, "twl6030_gpadc", gpadc);
>> + if (ret) {
>> + dev_dbg(&pdev->dev, "could not request irq\n");
>> + return ret;
>> + }
>> +
>> + ret = twl6030_gpadc_enable_irq(TWL6030_GPADC_RT_SW1_EOC_MASK);
>> + if (ret < 0) {
>> + dev_err(&pdev->dev, "Failed to enable GPADC interrupt\n");
>> + return ret;
>> + }
>
>New line here please.
>
>> + ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, TWL6030_GPADCS,
>> + TWL6030_REG_TOGGLE1);
>> + if (ret < 0) {
>> + dev_err(&pdev->dev, "Failed to enable GPADC module\n");
>> + return ret;
>> + }
>> +
>> + /* create as many sysfs entries as it really exists on the device */
>> + twl6030_gpadc_group.attrs[pdata->nchannels] = NULL;
>> + ret = sysfs_create_group(&pdev->dev.kobj, &twl6030_gpadc_group);
>> + if (ret)
>> + dev_err(&pdev->dev, "could not create sysfs files\n");
>> +
>> + return ret;
>> +}
>> +
>> +static int twl6030_gpadc_remove(struct platform_device *pdev)
>> +{
>> + twl6030_gpadc_disable_irq(TWL6030_GPADC_RT_SW1_EOC_MASK);
>> + sysfs_remove_group(&pdev->dev.kobj, &twl6030_gpadc_group);
>> +
>> + return 0;
>> +}
>> +
>> +static int twl6030_gpadc_suspend(struct device *pdev)
>> +{
>> + int ret;
>> +
>> + ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, TWL6030_GPADCR,
>> + TWL6030_REG_TOGGLE1);
>> + if (ret)
>> + pr_err("%s: Error reseting GPADC (%d)!\n", __func__, ret);
>> +
>> + return 0;
>> +};
>> +
>> +static int twl6030_gpadc_resume(struct device *pdev)
>> +{
>> + int ret;
>> +
>> + ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, TWL6030_GPADCS,
>> + TWL6030_REG_TOGGLE1);
>> + if (ret)
>> + pr_err("%s: Error setting GPADC (%d)!\n", __func__, ret);
>> +
>> + return 0;
>> +};
>> +
>> +static const struct dev_pm_ops twl6030_gpadc_pm_ops = {
>> + .suspend = twl6030_gpadc_suspend,
>> + .resume = twl6030_gpadc_resume,
>> +};
>> +
>> +static struct platform_driver twl6030_gpadc_driver = {
>> + .probe = twl6030_gpadc_probe,
>> + .remove = twl6030_gpadc_remove,
>> + .driver = {
>> + .name = DRIVER_NAME,
>> + .owner = THIS_MODULE,
>> + .pm = &twl6030_gpadc_pm_ops,
>> + .of_match_table = of_twl6030_match_tbl,
>> + },
>> +};
>> +
>> +module_platform_driver(twl6030_gpadc_driver);
>> +
>> +MODULE_ALIAS("platform: " DRIVER_NAME);
>> +MODULE_AUTHOR("Texas Instruments Inc.");
>> +MODULE_DESCRIPTION("twl6030 ADC driver");
>> +MODULE_LICENSE("GPL");
>> diff --git a/include/linux/i2c/twl6030-gpadc.h b/include/linux/i2c/twl6030-gpadc.h
>> new file mode 100644
>> index 0000000..5cd11e7
>> --- /dev/null
>> +++ b/include/linux/i2c/twl6030-gpadc.h
>> @@ -0,0 +1,51 @@
>> +/*
>> + * include/linux/i2c/twl6030-gpadc.h
>> + *
>> + * TWL6030 GPADC module driver header
>> + *
>> + * Copyright (C) 2009 Texas Instruments Inc.
>> + * Nishant Kamat <nskamat@xxxxxx>
>> + *
>> + * Based on twl4030-madc.h
>> + * Copyright (C) 2008 Nokia Corporation
>> + * Mikko Ylinen <mikko.k.ylinen@xxxxxxxxx>
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License
>> + * version 2 as published by the Free Software Foundation.
>> + *
>> + * 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 St, Fifth Floor, Boston, MA
>> + * 02110-1301 USA
>> + *
>> + */
>> +
>> +#ifndef _TWL6030_GPADC_H
>> +#define _TWL6030_GPADC_H
>> +
>> +
>> +/** struct twl6030_gpadc_result
>> + * @raw_code raw adc value from GPADC
>> + * @corrected_code corrected code calibrated adc value
>> + * @result calculated value
>> + */
>> +struct twl6030_gpadc_result {
>> + int raw_code;
>> + int corrected_code;
>> + int result;
>> +};
>> +
>> +/*
>> + * the user passes the bit mask of channels he wants to read converted values
>> + * end pointer to buffer allocated for the conversion results
>> + * on success returns 0.
>> + */
>> +int twl6030_gpadc_conversion(u32 channels, struct twl6030_gpadc_result *res);
>> +
>> +#endif
>
>--
>Lee Jones
>Linaro ST-Ericsson Landing Team Lead
>Linaro.org ? Open source software for ARM SoCs
>Follow Linaro: Facebook | Twitter | Blog
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