On Sun, May 03, 2015 at 08:10:15PM +0100, Jonathan Cameron wrote: > On 28/04/15 21:27, tduszyns@xxxxxxxxx wrote: > > On Mon, Apr 27, 2015 at 11:28:32PM +0200, Peter Meerwald wrote: > >> > >>> Add support for ROHM BH1710/BH1715/BH1721/BH1750/BH1751 ambient light > >>> sensors. > >> > >> some minor comments below > >> > >>> Signed-off-by: Tomasz Duszynski <tduszyns@xxxxxxxxx> > >>> --- > >>> Changes in v3: > >>> - Do some code cleanup > >>> - Add comments to clarify non-intuitive driver parts > >>> - Return proper scale value [lx / count] to userspace. In previous > >>> patches scale inverse was returned. > >>> > >>> Changes in v2: > >>> - Store chip-dependent values in chip_info structure > >>> - Add bh1750_remove to power down chip (necessary for BH1721) > >>> - Use one time mode for chips that have support for that > >>> - Use IIO_LIGHT instead of IIO_INTENSITY for channel type > >>> > >>> drivers/iio/light/Kconfig | 10 ++ > >>> drivers/iio/light/Makefile | 1 + > >>> drivers/iio/light/bh1750.c | 334 +++++++++++++++++++++++++++++++++++++++++++++ > >>> 3 files changed, 345 insertions(+) > >>> create mode 100644 drivers/iio/light/bh1750.c > >>> > >>> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig > >>> index 5a3237b..ebc578a 100644 > >>> --- a/drivers/iio/light/Kconfig > >>> +++ b/drivers/iio/light/Kconfig > >>> @@ -37,6 +37,16 @@ config APDS9300 > >>> To compile this driver as a module, choose M here: the > >>> module will be called apds9300. > >>> > >>> +config BH1750 > >>> + tristate "ROHM BH1750 ambient light sensor" > >>> + depends on I2C > >>> + help > >>> + Say Y here to build support for the ROHM BH1710, BH1715, BH1721, > >>> + BH1750, BH1751 ambient light sensors. > >>> + > >>> + To compile this driver as a module, choose M here: the module will > >>> + be called bh1750. > >>> + > >>> config CM32181 > >>> depends on I2C > >>> tristate "CM32181 driver" > >>> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile > >>> index 74656c1..1a13184 100644 > >>> --- a/drivers/iio/light/Makefile > >>> +++ b/drivers/iio/light/Makefile > >>> @@ -6,6 +6,7 @@ > >>> obj-$(CONFIG_ADJD_S311) += adjd_s311.o > >>> obj-$(CONFIG_AL3320A) += al3320a.o > >>> obj-$(CONFIG_APDS9300) += apds9300.o > >>> +obj-$(CONFIG_BH1750) += bh1750.o > >>> obj-$(CONFIG_CM32181) += cm32181.o > >>> obj-$(CONFIG_CM36651) += cm36651.o > >>> obj-$(CONFIG_GP2AP020A00F) += gp2ap020a00f.o > >>> diff --git a/drivers/iio/light/bh1750.c b/drivers/iio/light/bh1750.c > >>> new file mode 100644 > >>> index 0000000..9635a45 > >>> --- /dev/null > >>> +++ b/drivers/iio/light/bh1750.c > >>> @@ -0,0 +1,334 @@ > >>> +/* > >>> + * ROHM BH1710/BH1715/BH1721/BH1750/BH1751 ambient light sensor driver > >>> + * > >>> + * Copyright (c) Tomasz Duszynski <tduszyns@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. > >>> + * > >>> + * Data sheets: > >>> + * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1710fvc-e.pdf > >>> + * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1715fvc-e.pdf > >>> + * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1721fvc-e.pdf > >>> + * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1750fvi-e.pdf > >>> + * http://rohmfs.rohm.com/en/products/databook/datasheet/ic/sensor/light/bh1751fvi-e.pdf > >>> + * > >>> + * 7-bit I2C slave addresses: > >>> + * 0x23 (ADDR pin low) > >>> + * 0x5C (ADDR pin high) > >>> + * > >>> + */ > >>> + > >>> +#include <linux/delay.h> > >>> +#include <linux/i2c.h> > >>> +#include <linux/iio/iio.h> > >>> +#include <linux/iio/sysfs.h> > >>> +#include <linux/module.h> > >>> + > >>> +#define BH1750_POWER_DOWN 0x00 > >>> +#define BH1750_ONE_TIME_H_RES_MODE 0x20 /* auto-mode for BH1721 */ > >>> +#define BH1750_CHANGE_INT_TIME_H_BIT 0x40 > >>> +#define BH1750_CHANGE_INT_TIME_L_BIT 0x60 > >>> + > >>> +enum { > >>> + BH1710, > >>> + BH1721, > >>> + BH1750, > >>> +}; > >>> + > >>> +struct bh1750_chip_info; > >>> +struct bh1750_data { > >>> + struct i2c_client *client; > >>> + struct mutex lock; > >>> + const struct bh1750_chip_info *chip_info; > >>> + u16 mtreg; > >>> +}; > >>> + > >>> +struct bh1750_chip_info { > >>> + u16 mtreg_min; > >>> + u16 mtreg_max; > >>> + u16 mtreg_default; > >>> + int mtreg_to_usec; > >>> + int mtreg_to_scale; > >>> + > >>> + /* > >>> + * For BH1710/BH1721 all possible integration time values won't fit > >>> + * into one page so displaying is limited to every second one. > >>> + * Note, that user can still write proper values which were not > >>> + * listed. > >>> + */ > >>> + int inc; > >>> + > >>> + u16 int_time_low_mask; > >>> + u16 int_time_high_mask; > >>> +} > >>> + > >>> +static const bh1750_chip_info_tbl[] = { > >>> + [BH1710] = { 140, 1022, 300, 400, 250000000, 2, 0x001F, 0x03E0 }, > >>> + [BH1721] = { 140, 1020, 300, 400, 250000000, 2, 0x0010, 0x03E0 }, > >>> + [BH1750] = { 31, 254, 69, 1740, 57500000, 1, 0x001F, 0x00E0 }, > >>> +}; > >>> + > >>> +static int bh1750_change_int_time(struct bh1750_data *data, int usec) > >>> +{ > >>> + int ret; > >>> + u16 val; > >>> + u8 regval; > >>> + const struct bh1750_chip_info *chip_info = data->chip_info; > >>> + > >>> + if ((usec % chip_info->mtreg_to_usec) != 0) > >>> + return -EINVAL; > >>> + > >>> + val = usec / chip_info->mtreg_to_usec; > >>> + if (val < chip_info->mtreg_min || val > chip_info->mtreg_max) > >>> + return -EINVAL; > >>> + > >>> + ret = i2c_smbus_write_byte(data->client, BH1750_POWER_DOWN); > >>> + if (ret < 0) > >>> + return ret; > >>> + > >>> + regval = (val & chip_info->int_time_high_mask) >> 5; > >>> + ret = i2c_smbus_write_byte(data->client, > >>> + BH1750_CHANGE_INT_TIME_H_BIT | regval); > >>> + if (ret < 0) > >>> + return ret; > >>> + > >>> + regval = val & chip_info->int_time_low_mask; > >>> + ret = i2c_smbus_write_byte(data->client, > >>> + BH1750_CHANGE_INT_TIME_L_BIT | regval); > >>> + if (ret < 0) > >>> + return ret; > >>> + > >>> + data->mtreg = val; > >>> + > >>> + return 0; > >>> +} > >>> + > >>> +static int bh1750_read(struct bh1750_data *data, int *val) > >>> +{ > >>> + int ret; > >>> + u16 result; > >>> + const struct bh1750_chip_info *chip_info = data->chip_info; > >>> + unsigned long delay = chip_info->mtreg_to_usec * data->mtreg; > >>> + > >>> + /* > >>> + * BH1721 will enter continuous auto mode on receiving this command. > >> > >> maybe drop 'auto'? > >> > > OK, no problem for me. > >>> + * Note, that this eliminates need for bh1750_resume(). > >>> + */ > >>> + ret = i2c_smbus_write_byte(data->client, BH1750_ONE_TIME_H_RES_MODE); > >>> + if (ret < 0) > >>> + return ret; > >>> + > >>> + usleep_range(delay + 15000, delay + 40000); > >>> + > >>> + ret = i2c_master_recv(data->client, (char *)&result, 2); > >>> + if (ret < 0) > >>> + return ret; > >>> + > >>> + *val = swab16(result); > >> > >> I think be16_to_cpu() would be much clearer; > >> is swab16() correct on big-endian machines? > >> > > b16_to_cpu() totally fine for me. > > > > Correct me if I am wrong but I think swab16 here has to do with > > i2c protocol vs chip endianess not host endianess. Guess it will work equally > > good on both BE/LE machines. > That would have applied one of the specific length i2c commands was used. > The transmission for i2c should in theory be little endian,(but often isn't) > It is to deal with these case that we have the swapped functions. > i2c_smbus_write_word_swapped for example. > > Here the i2c subsystem has no way of knowing if you are reading two 1 byte > registers or 1 2 byte register. Hence it can't do the reordering and will > present them as a pair of bytes in whatever the wire order was. > > Hence you need to convert manually from bus endianness (whatever it is) > to cpu endianness. > > > Thanks for clarifying this. Anyway, I replaced swab16() with be16_to_cpu() in V4. > >>> + > >>> + return 0; > >>> +} > >>> + > >>> +static int bh1750_read_raw(struct iio_dev *indio_dev, > >>> + struct iio_chan_spec const *chan, > >>> + int *val, int *val2, long mask) > >>> +{ > >>> + int ret, tmp; > >>> + struct bh1750_data *data = iio_priv(indio_dev); > >>> + const struct bh1750_chip_info *chip_info = data->chip_info; > >>> + > >>> + switch (mask) { > >>> + case IIO_CHAN_INFO_RAW: > >>> + switch (chan->type) { > >>> + case IIO_LIGHT: > >>> + mutex_lock(&data->lock); > >>> + ret = bh1750_read(data, val); > >>> + mutex_unlock(&data->lock); > >>> + if (ret < 0) > >>> + return ret; > >>> + > >>> + return IIO_VAL_INT; > >>> + default: > >>> + return -EINVAL; > >>> + } > >>> + case IIO_CHAN_INFO_SCALE: > >>> + tmp = chip_info->mtreg_to_scale / data->mtreg; > >>> + *val = tmp / 1000000; > >>> + *val2 = tmp % 1000000; > >>> + return IIO_VAL_INT_PLUS_MICRO; > >>> + case IIO_CHAN_INFO_INT_TIME: > >>> + *val = 0; > >>> + *val2 = chip_info->mtreg_to_usec * data->mtreg; > >>> + return IIO_VAL_INT_PLUS_MICRO; > >>> + default: > >>> + return -EINVAL; > >>> + } > >>> +} > >>> + > >>> +static int bh1750_write_raw(struct iio_dev *indio_dev, > >>> + struct iio_chan_spec const *chan, > >>> + int val, int val2, long mask) > >>> +{ > >>> + int ret; > >>> + struct bh1750_data *data = iio_priv(indio_dev); > >>> + > >>> + switch (mask) { > >>> + case IIO_CHAN_INFO_INT_TIME: > >>> + if (val != 0) > >>> + return -EINVAL; > >>> + > >>> + mutex_lock(&data->lock); > >>> + ret = bh1750_change_int_time(data, val2); > >>> + mutex_unlock(&data->lock); > >>> + return ret; > >>> + default: > >>> + return -EINVAL; > >>> + } > >>> +} > >>> + > >>> +static ssize_t bh1750_show_int_time_available(struct device *dev, > >>> + struct device_attribute *attr, char *buf) > >>> +{ > >>> + int i; > >>> + size_t len = 0; > >>> + struct bh1750_data *data = iio_priv(dev_to_iio_dev(dev)); > >>> + const struct bh1750_chip_info *chip_info = data->chip_info; > >>> + > >>> + for (i = chip_info->mtreg_min; i <= chip_info->mtreg_max; i += chip_info->inc) > >>> + len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ", > >>> + chip_info->mtreg_to_usec * i); > >>> + > >>> + buf[len - 1] = '\n'; > >>> + > >>> + return len; > >>> +} > >>> + > >>> +static IIO_DEV_ATTR_INT_TIME_AVAIL(bh1750_show_int_time_available); > >>> + > >>> +static struct attribute *bh1750_attributes[] = { > >>> + &iio_dev_attr_integration_time_available.dev_attr.attr, > >>> + NULL, > >>> +}; > >>> + > >>> +static struct attribute_group bh1750_attribute_group = { > >>> + .attrs = bh1750_attributes, > >>> +}; > >>> + > >>> +static const struct iio_info bh1750_info = { > >>> + .driver_module = THIS_MODULE, > >>> + .attrs = &bh1750_attribute_group, > >>> + .read_raw = bh1750_read_raw, > >>> + .write_raw = bh1750_write_raw, > >>> +}; > >>> + > >>> +static const struct iio_chan_spec bh1750_channels[] = { > >>> + { > >>> + .type = IIO_LIGHT, > >>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > >>> + BIT(IIO_CHAN_INFO_SCALE) | > >>> + BIT(IIO_CHAN_INFO_INT_TIME) > >>> + } > >>> +}; > >>> + > >>> +static int bh1750_probe(struct i2c_client *client, > >>> + const struct i2c_device_id *id) > >>> +{ > >>> + int ret, usec; > >>> + struct bh1750_data *data; > >>> + struct iio_dev *indio_dev; > >>> + > >>> + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C | > >>> + I2C_FUNC_SMBUS_WRITE_BYTE)) > >>> + return -ENODEV; > >>> + > >>> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > >>> + if (!indio_dev) > >>> + return -ENOMEM; > >>> + > >>> + data = iio_priv(indio_dev); > >>> + i2c_set_clientdata(client, indio_dev); > >>> + data->client = client; > >>> + data->chip_info = &bh1750_chip_info_tbl[id->driver_data]; > >>> + > >>> + usec = data->chip_info->mtreg_to_usec * data->chip_info->mtreg_default; > >>> + ret = bh1750_change_int_time(data, usec); > >>> + if (ret < 0) > >>> + return ret; > >>> + > >>> + mutex_init(&data->lock); > >>> + indio_dev->dev.parent = &client->dev; > >>> + indio_dev->info = &bh1750_info; > >>> + indio_dev->name = id->name; > >>> + indio_dev->channels = bh1750_channels; > >>> + indio_dev->num_channels = ARRAY_SIZE(bh1750_channels); > >>> + indio_dev->modes = INDIO_DIRECT_MODE; > >>> + > >>> + return iio_device_register(indio_dev); > >>> +} > >>> + > >>> +static int bh1750_remove(struct i2c_client *client) > >>> +{ > >>> + struct iio_dev *indio_dev = i2c_get_clientdata(client); > >>> + struct bh1750_data *data = iio_priv(indio_dev); > >>> + > >>> + iio_device_unregister(indio_dev); > >>> + > >>> + mutex_lock(&data->lock); > >>> + i2c_smbus_write_byte(client, BH1750_POWER_DOWN); > >>> + mutex_unlock(&data->lock); > >>> + > >>> + return 0; > >>> +} > >>> + > >>> +#ifdef CONFIG_PM_SLEEP > >>> +static int bh1750_suspend(struct device *dev) > >>> +{ > >>> + int ret; > >>> + struct bh1750_data *data = > >>> + iio_priv(i2c_get_clientdata(to_i2c_client(dev))); > >>> + > >>> + /* > >>> + * This is mainly for BH1721 which doesn't enter power down > >>> + * mode automatically. > >>> + */ > >>> + mutex_lock(&data->lock); > >>> + ret = i2c_smbus_write_byte(data->client, BH1750_POWER_DOWN); > >>> + mutex_unlock(&data->lock); > >>> + > >>> + return ret; > >>> +} > >>> + > >>> +static SIMPLE_DEV_PM_OPS(bh1750_pm_ops, bh1750_suspend, NULL); > >>> +#define BH1750_PM_OPS (&bh1750_pm_ops) > >>> +#else > >>> +#define BH1750_PM_OPS NULL > >>> +#endif > >>> + > >>> +static const struct i2c_device_id bh1750_id[] = { > >>> + { "bh1710", BH1710 }, > >>> + { "bh1715", BH1750 }, > >>> + { "bh1721", BH1721 }, > >>> + { "bh1750", BH1750 }, > >>> + { "bh1751", BH1750 }, > >>> + { } > >>> +}; > >>> +MODULE_DEVICE_TABLE(i2c, bh1750_id); > >>> + > >>> +static struct i2c_driver bh1750_driver = { > >>> + .driver = { > >>> + .name = "bh1750", > >>> + .owner = THIS_MODULE, > >>> + .pm = BH1750_PM_OPS, > >>> + }, > >>> + .probe = bh1750_probe, > >>> + .remove = bh1750_remove, > >>> + .id_table = bh1750_id, > >>> + > >>> +}; > >>> +module_i2c_driver(bh1750_driver); > >>> + > >>> +MODULE_AUTHOR("Tomasz Duszynski <tduszyns@xxxxxxxxx>"); > >>> +MODULE_DESCRIPTION("ROHM BH1710/BH1715/BH1721/BH1750/BH1751 als driver"); > >>> +MODULE_LICENSE("GPL v2"); > >>> -- > >>> 2.3.6 > >>> > >> > >> -- > >> > >> Peter Meerwald > >> +43-664-2444418 (mobile) > -- 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
