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Message-ID: <alpine.DEB.2.01.1308121912590.26216@pmeerw.net>
Date: Mon, 12 Aug 2013 20:11:53 +0200 (CEST)
From: Peter Meerwald <pmeerw@...erw.net>
To: Kevin Tsai <ktsai@...ellamicro.com>
cc: Jonathan Cameron <jic23@....ac.uk>, linux-kernel@...r.kernel.org,
linux-iio@...r.kernel.org
Subject: Re: [PATCH 1/1] Added Capella CM3218 Ambient Light Sensor IIO
driver.
> drivers/iio/light/Kconfig | 10 +
> drivers/iio/light/Makefile | 1 +
> drivers/iio/light/cm3218.c | 589 +++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 600 insertions(+)
> create mode 100644 drivers/iio/light/cm3218.c
not much changed since last revision :(
some comments inline...
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index 5ef1a39..dd1ea80 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -15,6 +15,16 @@ config ADJD_S311
> This driver can also be built as a module. If so, the module
> will be called adjd_s311.
>
> +config SENSORS_CM3218
> + tristate "CM3218 Ambient Light Sensor"
> + depends on I2C
> + help
> + Say Y here if you have a Capella Micro CM3218 Ambient Light Sensor.
> +
> + To compile this driver as a module, choose M here. This module
> + will be called to 'cm3218'. It will access ALS data via iio sysfs.
will be called 'cm3218'. It will provide access to ALS data via iio
sysfs.
> + This is recommended.
I think this should be dropped; or do you mean one should prefer the
modules?
> +
> config SENSORS_LM3533
> tristate "LM3533 ambient light sensor"
> depends on MFD_LM3533
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index 040d9c7..c4ebe37 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -3,6 +3,7 @@
> #
>
> obj-$(CONFIG_ADJD_S311) += adjd_s311.o
> +obj-$(CONFIG_SENSORS_CM3218) += cm3218.o
> obj-$(CONFIG_SENSORS_LM3533) += lm3533-als.o
> obj-$(CONFIG_SENSORS_TSL2563) += tsl2563.o
> obj-$(CONFIG_VCNL4000) += vcnl4000.o
> diff --git a/drivers/iio/light/cm3218.c b/drivers/iio/light/cm3218.c
> new file mode 100644
> index 0000000..1989fbb
> --- /dev/null
> +++ b/drivers/iio/light/cm3218.c
> @@ -0,0 +1,589 @@
> +/*
> + * A iio driver for CM3218 Ambient Light Sensor.
> + *
> + * IIO driver for monitoring ambient light intensity in lux.
> + *
> + * Copyright (c) 2013, Capella Microsystems Inc.
> + *
> + * 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/module.h>
> +#include <linux/i2c.h>
> +#include <linux/err.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> +
> +#if 0 /* ChromeOS still uses old API */
> +#include "../iio.h"
> +#include "../sysfs.h"
> +#define IIO_DEVICE_ALLOC iio_allocate_device
> +#define IIO_DEVICE_FREE iio_free_device
> +#else
old kernels are not supported; drop this and use the correct funtion
directly
maybe you want to use devm_iio_device_alloc() introduced recently?
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#define IIO_DEVICE_ALLOC iio_device_alloc
> +#define IIO_DEVICE_FREE iio_device_free
> +#endif /* 0 */
> +
> +/*
> + * SMBus ARA address
> + */
> +#define CM3218_ADDR_ARA 0x0C
> +
> +/*
> + * CM3218 CMD Registers
> + */
> +#define CM3218_REG_ADDR_CMD 0x00
> +#define CM3218_CMD_ALS_SD 0x0001
> +#define CM3218_CMD_ALS_INT_EN 0x0002
> +#define CM3218_CMD_ALS_IT_SHIFT 6
> +#define CM3218_CMD_ALS_IT_MASK (3 << CM3218_CMD_ALS_IT_SHIFT)
> +#define CM3218_CMD_ALS_IT_05T (0 << CM3218_CMD_ALS_IT_SHIFT)
> +#define CM3218_CMD_ALS_IT_1T (1 << CM3218_CMD_ALS_IT_SHIFT)
> +#define CM3218_CMD_ALS_IT_2T (2 << CM3218_CMD_ALS_IT_SHIFT)
> +#define CM3218_CMD_ALS_IT_4T (3 << CM3218_CMD_ALS_IT_SHIFT)
> +#define CM3218_DEFAULT_CMD (CM3218_CMD_ALS_IT_1T)
parenthesis not necessary here: (CM3218_CMD_ALS_IT_1T)
> +
> +#define CM3218_REG_ADDR_ALS_WH 0x01
> +#define CM3218_DEFAULT_ALS_WH 0xFFFF
> +
> +#define CM3218_REG_ADDR_ALS_WL 0x02
> +#define CM3218_DEFAULT_ALS_WL 0x0000
> +
> +#define CM3218_REG_ADDR_ALS 0x04
> +
> +#define CM3218_REG_ADDR_STATUS 0x06
> +
> +#define CM3218_REG_ADDR_ID 0x07
> +
> +/*
> + * Software Parameters
> + */
single line comment: /* Software Parameters */
> +#define CM3218_MAX_CACHE_REGS (0x03+1) /* Reg.0x00 to 0x03 */
> +
> +/*
> + * Features
> + */
single line comment
> +#define CM3218_DEBUG
> +
> +static const unsigned short normal_i2c[] = {
> + 0x10, 0x48, I2C_CLIENT_END };
> +
> +struct cm3218_chip {
> + struct i2c_client *client;
> + struct mutex lock;
> + unsigned int lensfactor;
> + bool suspended;
> + u16 reg_cache[CM3218_MAX_CACHE_REGS];
> +};
> +
> +static int cm3218_read_ara(struct i2c_client *client)
> +{
> + int status;
> + unsigned short addr;
> +
> + addr = client->addr;
> + client->addr = CM3218_ADDR_ARA;
> + status = i2c_smbus_read_byte(client);
> + client->addr = addr;
> +
> + if (status < 0)
> + return -ENODEV;
> +
> + return 0;
> +}
> +
> +static int cm3218_write(struct i2c_client *client, u8 reg, u16 value)
> +{
> + int ret;
> + struct cm3218_chip *chip = iio_priv(i2c_get_clientdata(client));
> +
> +#ifdef CM3218_DEBUG
> + dev_err(&client->dev,
> + "Write to device register 0x%02X with 0x%04X\n", reg, value);
dev_dbg()?
> +#endif /* CM3218_DEBUG */
> + ret = i2c_smbus_write_word_data(client, reg, value);
> + if (ret) {
ret < 0?
> + dev_err(&client->dev, "Write to device fails: 0x%x\n", ret);
> + } else {
> + /* Update cache */
> + if (reg < CM3218_MAX_CACHE_REGS)
> + chip->reg_cache[reg] = value;
> + }
> +
> + return ret;
> +}
> +
> +static int cm3218_read(struct i2c_client *client, u8 reg)
> +{
> + int status;
> + struct cm3218_chip *chip = iio_priv(i2c_get_clientdata(client));
> +
> + if (reg < CM3218_MAX_CACHE_REGS) {
> + status = chip->reg_cache[reg];
> + } else {
> + status = i2c_smbus_read_word_data(client, reg);
> + if (status < 0) {
> + dev_err(&client->dev,
> + "Error in reading Reg.0x%02X\n", reg);
> + return status;
return not needed here
> + }
> +#ifdef CM3218_DEBUG
> + dev_err(&client->dev,
> + "Read from device register 0x%02X = 0x%04X\n",
> + reg, status);
> +#endif /* CM3218_DEBUG */
> + }
> +
> + return status;
> +}
> +
> +static int cm3218_read_sensor_input(struct i2c_client *client)
> +{
> + int status;
> +
> + status = cm3218_read(client, CM3218_REG_ADDR_ALS);
> + if (status < 0)
> + return status;
> +
> + dev_vdbg(&client->dev, "lux = %u\n", status);
> +
> + return status;
> +}
drop this function and inline into read_lux()
> +
> +static int cm3218_read_lux(struct i2c_client *client, int *lux)
> +{
> + struct cm3218_chip *chip = iio_priv(i2c_get_clientdata(client));
> + int lux_data;
> +
> + lux_data = cm3218_read_sensor_input(client);
> +
> + if (lux_data < 0)
> + return lux_data;
> +
> + *lux = lux_data * chip->lensfactor;
> + *lux /= 1000;
> + return 0;
> +}
> +
> +/* Sysfs interface */
> +/* lensfactor */
use multi-line comment
> +static ssize_t show_lensfactor(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct cm3218_chip *chip = iio_priv(indio_dev);
struct cm3218_chip *chip = iio_priv(dev_get_drvdata(dev));
> +
> + return sprintf(buf, "%d\n", chip->lensfactor);
> +}
you don't need this, handled by channel read/write below
> +
> +static ssize_t store_lensfactor(struct device *dev,
> + struct device_attribute *attr, const char *buf, size_t count)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct cm3218_chip *chip = iio_priv(indio_dev);
> + unsigned long lval;
> +
> + if (kstrtoul(buf, 10, &lval))
> + return -EINVAL;
> +
> + mutex_lock(&chip->lock);
> + chip->lensfactor = lval;
> + mutex_unlock(&chip->lock);
> +
> + return count;
> +}
you don't need this, handled by channel read/write below
no range checking??
> +
> +static ssize_t get_sensor_data(struct device *dev, char *buf)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct cm3218_chip *chip = iio_priv(indio_dev);
> + struct i2c_client *client = chip->client;
> + int value = 0;
> + int status;
> +
> + mutex_lock(&chip->lock);
> + if (chip->suspended) {
> + mutex_unlock(&chip->lock);
> + return -EBUSY;
> + }
> +
> + status = cm3218_read_lux(client, &value);
extra space at beginning of line
> +
> + if (status < 0) {
> + dev_err(&client->dev, "Error in Reading data");
reading
> + mutex_unlock(&chip->lock);
> + return status;
> + }
> +
> + mutex_unlock(&chip->lock);
> +
> + return sprintf(buf, "%d\n", value);
> +}
> +
> +
> +/* Read lux */
> +static ssize_t show_lux(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + return get_sensor_data(dev, buf);
> +}
drop this; use channels to present data
> +
> +#ifdef CM3218_DEBUG
> +/* windows_high */
> +static ssize_t show_cmd(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct cm3218_chip *chip = iio_priv(indio_dev);
> + struct i2c_client *client = chip->client;
> + int status;
> +
> + status = cm3218_read(client, CM3218_REG_ADDR_CMD);
> + if (status < 0) {
> + dev_err(dev, "Error in getting CM3218_REG_ADDR_CMD\n");
> + return status;
> + }
> +
> + return sprintf(buf, "%u\n", status);
> +}
I'd rather drop the debugging stuff; you could use
probably use iio_info.debugfs_reg_access:
> +
> +static ssize_t store_cmd(struct device *dev,
> + struct device_attribute *attr, const char *buf, size_t count)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct cm3218_chip *chip = iio_priv(indio_dev);
> + struct i2c_client *client = chip->client;
> + int status;
> + unsigned long lval;
> +
> + if (kstrtoul(buf, 10, &lval))
> + return -EINVAL;
> +
> + mutex_lock(&chip->lock);
> + if (lval > 0x10000)
>= maybe?
> + lval = 0xFFFF;
> + status = cm3218_write(client, CM3218_REG_ADDR_CMD, (u16)lval);
> + if (status < 0) {
> + mutex_unlock(&chip->lock);
> + dev_err(dev, "Error in setting CM3218_REG_ADDR_CMD\n");
> + return status;
> + }
> + mutex_unlock(&chip->lock);
> +
> + return count;
> +}
> +
> +/* status */
> +static ssize_t show_status(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct cm3218_chip *chip = iio_priv(indio_dev);
> + struct i2c_client *client = chip->client;
> + int status;
> +
> + status = cm3218_read(client, CM3218_REG_ADDR_STATUS);
> + if (status < 0) {
> + dev_err(dev, "Error in getting CM3218_REG_ADDR_STATUS\n");
> + return status;
> + }
> +
> + return sprintf(buf, "%u\n", status);
> +}
> +
> +#endif /* CM3218_DEBUG */
> +
> +/* Channel IO */
> +static int cm3218_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int val,
> + int val2,
> + long mask)
> +{
> + struct cm3218_chip *chip = iio_priv(indio_dev);
> + int ret = -EINVAL;
ret is not used, only assigned
> +
> + mutex_lock(&chip->lock);
> + if (mask == IIO_CHAN_INFO_CALIBSCALE && chan->type == IIO_LIGHT) {
> + chip->lensfactor = val;
> + ret = 0;
> + }
> + mutex_unlock(&chip->lock);
> +
> + return 0;
> +}
> +
> +static int cm3218_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val,
> + int *val2,
> + long mask)
> +{
> + int ret = -EINVAL;
> + struct cm3218_chip *chip = iio_priv(indio_dev);
> + struct i2c_client *client = chip->client;
> +
> + mutex_lock(&chip->lock);
> + if (chip->suspended) {
> + mutex_unlock(&chip->lock);
> + return -EBUSY;
> + }
> + switch (mask) {
> + case 0:
INFO_RAW? or INFO_PROCESSED?
> + ret = cm3218_read_lux(client, val);
> + if (!ret)
> + ret = IIO_VAL_INT;
if (ret >= 0) ??
> + break;
> + case IIO_CHAN_INFO_CALIBSCALE:
> + *val = chip->lensfactor;
> + ret = IIO_VAL_INT_PLUS_MICRO;
> + break;
> + default:
> + break;
> + }
> + mutex_unlock(&chip->lock);
> + return ret;
> +}
> +
> +#define IIO_CHAN_INFO_SEPARATE_BIT(type) BIT(type*2 + 1)
> +#define IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT \
> + IIO_CHAN_INFO_SEPARATE_BIT(IIO_CHAN_INFO_CALIBSCALE)
only needed for old kernels
> +
> +static const struct iio_chan_spec cm3218_channels[] = {
> + {
> + .type = IIO_LIGHT,
> + .indexed = 1,
there is only one channel, no need to index
> + .channel = 0,
> + .info_mask = IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT,
INFO_RAW/PROCESSED?
> + }
> +};
> +
> +static IIO_DEVICE_ATTR(illuminance0_input, S_IRUGO, show_lux, NULL, 0);
> +static IIO_DEVICE_ATTR(illuminance0_calibscale, S_IRUGO | S_IWUSR,
> + show_lensfactor, store_lensfactor, 0);
> +#ifdef CM3218_DEBUG
> +static IIO_DEVICE_ATTR(cmd, S_IRUGO | S_IWUSR, show_cmd, store_cmd, 0);
> +static IIO_DEVICE_ATTR(status, S_IRUGO, show_status, NULL, 0);
> +#endif /* CM3218_DEBUG */
> +
> +#define CM3218_DEV_ATTR(name) (&iio_dev_attr_##name.dev_attr.attr)
> +#define CM3218_CONST_ATTR(name) (&iio_const_attr_##name.dev_attr.attr)
> +static struct attribute *cm3218_attributes[] = {
> + CM3218_DEV_ATTR(illuminance0_input),
> + CM3218_DEV_ATTR(illuminance0_calibscale),
> +#ifdef CM3218_DEBUG
> + CM3218_DEV_ATTR(cmd),
> + CM3218_DEV_ATTR(status),
> +#endif /* CM3218_DEBUG */
> + NULL
> +};
> +
> +static const struct attribute_group cm3218_group = {
> + .attrs = cm3218_attributes,
> +};
> +
> +static int cm3218_chip_init(struct i2c_client *client)
> +{
> + struct cm3218_chip *chip = iio_priv(i2c_get_clientdata(client));
> + int status, i;
> +
> + memset(chip->reg_cache, 0, sizeof(chip->reg_cache));
> +
> + for (i = 0; i < 5; i++) {
> + status = cm3218_write(client, CM3218_REG_ADDR_CMD,
> + CM3218_CMD_ALS_SD);
> + if (status >= 0)
> + break;
> + cm3218_read_ara(client);
why 5 times? no sleep?
> + }
> +
> + status = cm3218_write(client, CM3218_REG_ADDR_CMD, CM3218_DEFAULT_CMD);
> + if (status < 0) {
> + dev_err(&client->dev, "Init CM3218 CMD fails\n");
> + return status;
> + }
> +
> +
> + /* Clean interrupt status */
> + cm3218_read(client, CM3218_REG_ADDR_STATUS);
> +
> + return 0;
> +}
> +
> +static const struct iio_info cm3218_info = {
> + .attrs = &cm3218_group,
> + .driver_module = THIS_MODULE,
> + .read_raw = &cm3218_read_raw,
> + .write_raw = &cm3218_write_raw,
> +};
> +
> +static int cm3218_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct cm3218_chip *chip;
> + struct iio_dev *indio_dev;
> + int err;
> +
> + indio_dev = IIO_DEVICE_ALLOC(sizeof(*chip));
> + if (indio_dev == NULL) {
> + dev_err(&client->dev, "iio allocation fails\n");
drop error msg
> + err = -ENOMEM;
> + goto exit;
> + }
> + chip = iio_priv(indio_dev);
> + chip->client = client;
> + i2c_set_clientdata(client, indio_dev);
> +
> + mutex_init(&chip->lock);
> +
> + chip->lensfactor = 1000;
> + chip->suspended = false;
> +
> + err = cm3218_chip_init(client);
> + if (err)
> + goto exit_iio_free;
> +
> + indio_dev->info = &cm3218_info;
> + indio_dev->channels = cm3218_channels;
> + indio_dev->num_channels = ARRAY_SIZE(cm3218_channels);
> + indio_dev->name = id->name;
> + indio_dev->dev.parent = &client->dev;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + err = iio_device_register(indio_dev);
> + if (err) {
> + dev_err(&client->dev, "iio registration fails\n");
> + goto exit_iio_free;
> + }
> +
> + return 0;
> +exit_iio_free:
> + IIO_DEVICE_FREE(indio_dev);
> +exit:
> + return err;
> +}
> +
> +static int cm3218_detect(struct i2c_client *client,
> + struct i2c_board_info *info)
> +{
> + struct i2c_adapter *adapter = client->adapter;
> + const char *name = NULL;
> + int id;
> +
> + cm3218_read_ara(client);
> +
> + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
> + return -ENODEV;
> +
> + id = cm3218_read(client, CM3218_REG_ADDR_ID);
> + if (id < 0)
> + return -ENODEV;
> +
> + switch (id&0xFF) {
> + case 0x18:
> + name = "cm3218";
> + break;
> + default:
> + return -ENODEV;
> + }
> +
> + strlcpy(info->type, name, I2C_NAME_SIZE);
> +
> + return 0;
> +}
drop detect code
> +
> +static int cm3218_remove(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> + dev_dbg(&client->dev, "%s()\n", __func__);
> + iio_device_unregister(indio_dev);
> + IIO_DEVICE_FREE(indio_dev);
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int cm3218_suspend(struct device *dev)
> +{
> + struct cm3218_chip *chip = iio_priv(dev_get_drvdata(dev));
> +
> + mutex_lock(&chip->lock);
> +
> + /* Since this driver uses only polling commands, we are by default in
> + * auto shutdown (ie, power-down) mode.
> + * So we do not have much to do here.
> + */
> + chip->suspended = true;
> +
> + mutex_unlock(&chip->lock);
> + return 0;
> +}
> +
> +static int cm3218_resume(struct device *dev)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct cm3218_chip *chip = iio_priv(indio_dev);
> + struct i2c_client *client = chip->client;
> + int err;
> +
> + mutex_lock(&chip->lock);
> +
> + err = cm3218_chip_init(client);
> + if (!err)
> + chip->suspended = false;
> +
> + mutex_unlock(&chip->lock);
> + return err;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(cm3218_pm_ops, cm3218_suspend, cm3218_resume);
> +#define CM3218_PM_OPS (&cm3218_pm_ops)
> +#else
> +#define CM3218_PM_OPS NULL
> +#endif
> +
> +static const struct i2c_device_id cm3218_id[] = {
> + {"cm3218", 0},
> + {}
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, cm3218_id);
> +
> +static const struct of_device_id cm3218_of_match[] = {
> + { .compatible = "invn,cm3218", },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, cm3218_of_match);
> +
> +static struct i2c_driver cm3218_driver = {
> + .class = I2C_CLASS_HWMON,
> + .driver = {
> + .name = "cm3218",
> + .pm = CM3218_PM_OPS,
> + .owner = THIS_MODULE,
> + .of_match_table = cm3218_of_match,
> + },
> + .probe = cm3218_probe,
> + .remove = cm3218_remove,
> + .id_table = cm3218_id,
> + .detect = cm3218_detect,
> + .address_list = normal_i2c,
> +};
> +module_i2c_driver(cm3218_driver);
> +
> +MODULE_DESCRIPTION("CM3218 Ambient Light Sensor driver");
> +MODULE_LICENSE("GPL");
>
--
Peter Meerwald
+43-664-2444418 (mobile)
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