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Message-ID: <51D53988.7040808@metafoo.de>
Date: Thu, 04 Jul 2013 10:59:52 +0200
From: Lars-Peter Clausen <lars@...afoo.de>
To: Kevin Tsai <ktsai@...ellamicro.com>
CC: Jonathan Cameron <jic23@....ac.uk>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Grant Likely <grant.likely@...aro.org>,
Rob Herring <rob.herring@...xeda.com>,
Peter Meerwald <pmeerw@...erw.net>,
linux-kernel@...r.kernel.org, linux-iio@...r.kernel.org,
devel@...verdev.osuosl.org, devicetree-discuss@...ts.ozlabs.org
Subject: Re: [PATCH 1/1] Added Capella CM3218 Ambient Light Sensor IIO Driver.
On 07/04/2013 01:31 AM, Kevin Tsai wrote:
Maybe write at least a short commit message which states the features of the
chip.
> Signed-off-by: Kevin Tsai <ktsai@...ellamicro.com>
> ---
> drivers/staging/iio/light/Kconfig | 10 +
> drivers/staging/iio/light/Makefile | 1 +
> drivers/staging/iio/light/cm3218.c | 581 ++++++++++++++++++++++++++++++++++++
> 3 files changed, 592 insertions(+)
> create mode 100644 drivers/staging/iio/light/cm3218.c
>
> diff --git a/drivers/staging/iio/light/Kconfig b/drivers/staging/iio/light/Kconfig
> index ca8d6e6..647af0c 100644
> --- a/drivers/staging/iio/light/Kconfig
> +++ b/drivers/staging/iio/light/Kconfig
> @@ -40,4 +40,14 @@ config TSL2x7x
> tmd2672, tsl2772, tmd2772 devices.
> Provides iio_events and direct access via sysfs.
>
> +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.
> + This is recommended.
> +
Keep the entries in alphabetical order.
> endmenu
> diff --git a/drivers/staging/iio/light/Makefile b/drivers/staging/iio/light/Makefile
> index 9960fdf..63020ab 100644
> --- a/drivers/staging/iio/light/Makefile
> +++ b/drivers/staging/iio/light/Makefile
> @@ -6,3 +6,4 @@ obj-$(CONFIG_SENSORS_ISL29018) += isl29018.o
> obj-$(CONFIG_SENSORS_ISL29028) += isl29028.o
> obj-$(CONFIG_TSL2583) += tsl2583.o
> obj-$(CONFIG_TSL2x7x) += tsl2x7x_core.o
> +obj-$(CONFIG_SENSORS_CM3218) += cm3218.o
Same here
> diff --git a/drivers/staging/iio/light/cm3218.c b/drivers/staging/iio/light/cm3218.c
> new file mode 100644
> index 0000000..9c2584d
> --- /dev/null
> +++ b/drivers/staging/iio/light/cm3218.c
> @@ -0,0 +1,581 @@
[...]
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/err.h>
> +#include <linux/mutex.h>
> +#include <linux/delay.h>
delay.h seems to be unused
> +#include <linux/slab.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
[...]
> +
> +static int cm3218_write(struct i2c_client *client, u8 reg, u16 value)
> +{
> + u16 regval;
> + 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);
> +#endif /* CM3218_DEBUG */
> + regval = cpu_to_le16(value);
> + ret = i2c_smbus_write_word_data(client, reg, regval);
This looks wrong, with this code the on-wire byteorder will differ between
big endian and little endian systems. Maybe you want
i2c_smbus_write_word_swapped?
But as Peter said, just use regmap for all IO.
> + if (ret) {
> + 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_detect(struct i2c_client *client,
> + struct i2c_board_info *info)
> +{
> + struct i2c_adapter *adapter = client->adapter;
> + const char *name = NULL;
> +
> + cm3218_read_ara(client);
> +
> + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
> + return -ENODEV;
> +
> + name = "cm3218";
> + strlcpy(info->type, name, I2C_NAME_SIZE);
> +
Always returning zero means the chip will bind to any I2C devices which
happen to use the same address. I don't think you actually need detection,
so just remove it.
> + return 0;
> +}
> +
> +static const struct i2c_device_id cm3218_id[] = {
> + {"cm3218", 0},
> + {}
> +};
> +
Nitpick: no need for the newline
> +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,
> + },
Indention looks a bit strange here. Please use one tab per level.
> + .probe = cm3218_probe,
> + .remove = cm3218_remove,
> + .id_table = cm3218_id,
> + .detect = cm3218_detect,
> + .address_list = normal_i2c,
> +};
> +module_i2c_driver(cm3218_driver);
--
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