Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966121AbbD1UdD (ORCPT ); Tue, 28 Apr 2015 16:33:03 -0400 Received: from mail-la0-f48.google.com ([209.85.215.48]:33164 "EHLO mail-la0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966030AbbD1Uc6 (ORCPT ); Tue, 28 Apr 2015 16:32:58 -0400 Date: Tue, 28 Apr 2015 22:27:45 +0200 From: tduszyns@gmail.com To: Peter Meerwald Cc: Tomasz Duszynski , jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org Subject: Re: [PATCH v3] iio: light: add support for ROHM BH1710/BH1715/BH1721/BH1750/BH1751 ambient light sensors Message-ID: <20150428202745.GA23285@Arch.lan> References: <1430155127-16898-1-git-send-email-tduszyns@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 13082 Lines: 426 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 > > --- > > 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 > > + * > > + * 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 > > +#include > > +#include > > +#include > > +#include > > + > > +#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. > > + > > + 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 "); > > +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-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/