On Mon, Sep 1, 2014 at 8:39 PM, Peter Meerwald <pmeerw@xxxxxxxxxx> wrote: > Hello Daniel, > >> Minimal implementation. This driver provides raw illuminance readings. >> >> This is based on drivers/hwmon/al3320.c (*) driver from msm tree written >> by Tsechih Lin <Tsechih_Lin@xxxxxxxx> >> >> * https://android.googlesource.com/kernel/msm.git >> >> Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx> >> --- >> Changes since v3: (reported by Hartmut and Jonathan) >> * dropped the local store for the range, instead read it when necessary >> * removed wrapper functions >> * added in_illuminance_scale_available attribute >> * fix bug when reading raw value, use i2c_smbus_read_word instead of >> i2c_smbus_read_word_swapped and fix the endianess after read. > > no need to fix endianness > >> * small coding style fixes >> >> Changes since v2: (reported by Peter Meerwald) >> * removed definition of DATA_HIGH and SW_RESET as they are not used >> * added a comment to al3320a_get_adc_value() function >> * added thresholds on TODO list >> * small style fixes >> >> Changes since v1: (reported by Peter Meerwald) >> * used u8 instead of int for passing gain and mean_time >> * used i2c_smbus_read_word_swapped instead of 2 x i2c_smbus_read_byte_data >> * used devm_iio_device_register instead of iio_device_register >> * small style fixes >> >> >> drivers/iio/light/Kconfig | 10 ++ >> drivers/iio/light/Makefile | 1 + >> drivers/iio/light/al3320a.c | 229 ++++++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 240 insertions(+) >> create mode 100644 drivers/iio/light/al3320a.c >> >> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig >> index bf05ca5..5bea821 100644 >> --- a/drivers/iio/light/Kconfig >> +++ b/drivers/iio/light/Kconfig >> @@ -17,6 +17,16 @@ config ADJD_S311 >> This driver can also be built as a module. If so, the module >> will be called adjd_s311. >> >> +config AL3320A >> + tristate "AL3320A ambient light sensor" >> + depends on I2C >> + help >> + Say Y here if you want to build a driver for the Dyna Image AL3320A >> + ambient light sensor. >> + >> + To compile this driver as a module, choose M here: the >> + module will be called al3320a. >> + >> config APDS9300 >> tristate "APDS9300 ambient light sensor" >> depends on I2C >> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile >> index 8b8c09f..47877a3 100644 >> --- a/drivers/iio/light/Makefile >> +++ b/drivers/iio/light/Makefile >> @@ -4,6 +4,7 @@ >> >> # When adding new entries keep the list in alphabetical order >> obj-$(CONFIG_ADJD_S311) += adjd_s311.o >> +obj-$(CONFIG_AL3320A) += al3320a.o >> obj-$(CONFIG_APDS9300) += apds9300.o >> obj-$(CONFIG_CM32181) += cm32181.o >> obj-$(CONFIG_CM36651) += cm36651.o >> diff --git a/drivers/iio/light/al3320a.c b/drivers/iio/light/al3320a.c >> new file mode 100644 >> index 0000000..ad9135a >> --- /dev/null >> +++ b/drivers/iio/light/al3320a.c >> @@ -0,0 +1,229 @@ >> +/* >> + * AL3320A - Dyna Image Ambient Light Sensor >> + * >> + * Copyright (c) 2014, Intel Corporation. >> + * >> + * This file is subject to the terms and conditions of version 2 of >> + * the GNU General Public License. See the file COPYING in the main >> + * directory of this archive for more details. >> + * >> + * IIO driver for AL3320A (7-bit I2C slave address 0x1C). >> + * >> + * TODO: interrupt support, thresholds >> + * >> + */ >> + >> +#include <linux/module.h> >> +#include <linux/init.h> >> +#include <linux/i2c.h> >> + >> +#include <linux/iio/iio.h> >> +#include <linux/iio/sysfs.h> >> + >> +#define AL3320A_DRV_NAME "al3320a" >> + >> +#define AL3320A_REG_CONFIG 0x00 >> +#define AL3320A_REG_STATUS 0x01 >> +#define AL3320A_REG_INT 0x02 >> +#define AL3320A_REG_WAIT 0x06 >> +#define AL3320A_REG_CONFIG_RANGE 0x07 >> +#define AL3320A_REG_PERSIST 0x08 >> +#define AL3320A_REG_MEAN_TIME 0x09 >> +#define AL3320A_REG_ADUMMY 0x0A >> +#define AL3320A_REG_DATA_LOW 0x22 >> + >> +#define AL3320A_REG_LOW_THRESH_LOW 0x30 >> +#define AL3320A_REG_LOW_THRESH_HIGH 0x31 >> +#define AL3320A_REG_HIGH_THRESH_LOW 0x32 >> +#define AL3320A_REG_HIGH_THRESH_HIGH 0x33 >> + >> +#define AL3320A_CONFIG_DISABLE 0x00 >> +#define AL3320A_CONFIG_ENABLE 0x01 >> + >> +#define AL3320A_GAIN_SHIFT 1 >> + >> +/* chip params default values */ >> +#define AL3320A_DEFAULT_MEAN_TIME 4 >> +#define AL3320A_DEFAULT_WAIT_TIME 0 /* no waiting */ >> + >> +#define AL3320A_SCALE_AVAILABLE "0.512 0.128 0.032 0.01" >> + >> +enum al3320a_range { >> + AL3320A_RANGE_1, /* 33.28K lux */ >> + AL3320A_RANGE_2, /* 8.32K lux */ >> + AL3320A_RANGE_3, /* 2.08K lux */ >> + AL3320A_RANGE_4 /* 0.65K lux */ >> +}; >> + >> +static const int al3320a_scales[][2] = { >> + {0, 512000}, {0, 128000}, {0, 32000}, {0, 10000} >> +}; >> + >> +struct al3320a_data { >> + struct i2c_client *client; >> +}; >> + >> +static const struct iio_chan_spec al3320a_channels[] = { >> + { >> + .type = IIO_LIGHT, >> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | >> + BIT(IIO_CHAN_INFO_SCALE), >> + } >> +}; >> + >> +static IIO_CONST_ATTR(in_illuminance_scale_available, AL3320A_SCALE_AVAILABLE); >> + >> +static struct attribute *al3320a_attributes[] = { >> + &iio_const_attr_in_illuminance_scale_available.dev_attr.attr, >> + NULL, >> +}; >> + >> +static const struct attribute_group al3320a_attribute_group = { >> + .attrs = al3320a_attributes, >> +}; >> + >> +static int al3320a_init(struct al3320a_data *data) >> +{ >> + int ret; >> + >> + /* power on */ >> + ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG, >> + AL3320A_CONFIG_ENABLE); >> + if (ret < 0) >> + return ret; >> + >> + ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG_RANGE, >> + AL3320A_RANGE_3 << AL3320A_GAIN_SHIFT); >> + if (ret < 0) >> + return ret; >> + >> + ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_MEAN_TIME, >> + AL3320A_DEFAULT_MEAN_TIME); >> + if (ret < 0) >> + return ret; >> + >> + ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_WAIT, >> + AL3320A_DEFAULT_WAIT_TIME); >> + if (ret < 0) >> + return ret; >> + >> + return 0; >> +} >> + >> +static int al3320a_read_raw(struct iio_dev *indio_dev, >> + struct iio_chan_spec const *chan, int *val, >> + int *val2, long mask) >> +{ >> + struct al3320a_data *data = iio_priv(indio_dev); >> + int ret; >> + >> + switch (mask) { >> + case IIO_CHAN_INFO_RAW: >> + /* >> + * ALS ADC value is stored in two adjacent registers: >> + * - low byte of output is stored at AL3320A_REG_DATA_LOW >> + * - high byte of output is stored at AL3320A_REG_DATA_LOW + 1 >> + */ >> + ret = i2c_smbus_read_word_data(data->client, >> + AL3320A_REG_DATA_LOW); > > i2c_smbus_read_word_data() must be used if the data is in I2C byte order > (i.e. LSB first) > > i2c_smbus_read_word_swapped() must be used if the data is NOT in I2C byte > order (i.e. MSB first) > > this has nothing to do with CPU byteorder; i2c_smbus_read_word_xxx() will > take care to report the 16-bit value in native endianness > >> + if (ret < 0) >> + return ret; >> + *val = le16_to_cpu((__le16)ret); > > so it should be > *val = ret; I see. thanks! I will fix this asap. Daniel. -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
