Re: [PATCH v2 1/2] hwmon: (ads7828) driver cleanup

Vivien Didelot
2012-10-02T02:21:36Z

Hi Guenter,

On Mon, 2012-10-01 at 18:07 -0700, Guenter Roeck wrote:
> On Mon, Oct 01, 2012 at 07:16:23PM -0400, Vivien Didelot wrote:
> > * Remove unused macros;
> > * Point to the documentation;
> > * Coding Style fixes (Kernel Doc, spacing);
> > * Move driver declaration to avoid adding function prototypes.
> >
> > Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
>
> Hi Vivien,
>
> > ---
> > drivers/hwmon/ads7828.c | 91 +++++++++++++++++++++++--------------------------
> > 1 file changed, 43 insertions(+), 48 deletions(-)
> >
> > diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c
> > index bf3fdf4..fb3010d 100644
> > --- a/drivers/hwmon/ads7828.c
> > +++ b/drivers/hwmon/ads7828.c
> > @@ -6,7 +6,7 @@
> > *
> > * Written by Steve Hardy <shardy@redhat.com>
> > *
> > - * Datasheet available at: http://focus.ti.com/lit/ds/symlink/ads7828.pdf
> > + * For further information, see the Documentation/hwmon/ads7828 file.
> > *
> > * 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
> > @@ -34,14 +34,12 @@
> > #include <linux/mutex.h>
> >
> > /* The ADS7828 registers */
> > -#define ADS7828_NCH 8 /* 8 channels of 12-bit A-D supported */
> > -#define ADS7828_CMD_SD_SE 0x80 /* Single ended inputs */
> > -#define ADS7828_CMD_SD_DIFF 0x00 /* Differential inputs */
> > -#define ADS7828_CMD_PD0 0x0 /* Power Down between A-D conversions */
> > -#define ADS7828_CMD_PD1 0x04 /* Internal ref OFF && A-D ON */
> > -#define ADS7828_CMD_PD2 0x08 /* Internal ref ON && A-D OFF */
> > -#define ADS7828_CMD_PD3 0x0C /* Internal ref ON && A-D ON */
> > -#define ADS7828_INT_VREF_MV 2500 /* Internal vref is 2.5V, 2500mV */
> > +#define ADS7828_NCH 8 /* 8 channels supported */
> > +#define ADS7828_CMD_SD_SE 0x80 /* Single ended inputs */
> > +#define ADS7828_CMD_SD_DIFF 0x00 /* Differential inputs */
> > +#define ADS7828_CMD_PD1 0x04 /* Internal ref OFF && A/D ON */
> > +#define ADS7828_CMD_PD3 0x0C /* Internal ref ON && A/D ON */
> > +#define ADS7828_INT_VREF_MV 2500 /* Internal vref is 2.5V, 2500mV */
> >
> > /* Addresses to scan */
> > static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
> > @@ -59,25 +57,26 @@ module_param(vref_mv, int, S_IRUGO);
> > static u8 ads7828_cmd_byte; /* cmd byte without channel bits */
> > static unsigned int ads7828_lsb_resol; /* resolution of the ADC sample lsb */
> >
> > -/* Each client has this additional data */
> > +/**
> > + * struct ads7828_data - client specific data
> > + * @hwmon_dev: The hwmon device.
> > + * @update_lock: Mutex protecting updates.
> > + * @valid: Validity flag.
> > + * @last_updated: Last updated time (in jiffies).
> > + * @adc_input: ADS7828_NCH samples.
> > + */
> This isn't really an externally visible API, so I wonder if it provides value to
> document it this way. No strong opinion, just wondering.
I found the version below a bit cluttered, that's why I used the
KernelDoc notation. Would you prefer something else, like right-aligned
comments?
>
> > struct ads7828_data {
> > struct device *hwmon_dev;
> > - struct mutex update_lock; /* mutex protect updates */
> > - char valid; /* !=0 if following fields are valid */
> > - unsigned long last_updated; /* In jiffies */
> > - u16 adc_input[ADS7828_NCH]; /* ADS7828_NCH 12-bit samples */
> > + struct mutex update_lock;
> > + char valid;
> > + unsigned long last_updated;
> > + u16 adc_input[ADS7828_NCH];
> > };
> >
> > -/* Function declaration - necessary due to function dependencies */
> > -static int ads7828_detect(struct i2c_client *client,
> > - struct i2c_board_info *info);
> > -static int ads7828_probe(struct i2c_client *client,
> > - const struct i2c_device_id *id);
> > -
> > static inline u8 channel_cmd_byte(int ch)
> > {
> > /* cmd byte C2,C1,C0 - see datasheet */
> > - u8 cmd = (((ch>>1) | (ch&0x01)<<2)<<4);
> > + u8 cmd = (((ch >> 1) | (ch & 0x01) << 2) << 4);
> > cmd |= ads7828_cmd_byte;
> > return cmd;
> > }
> > @@ -120,9 +119,8 @@ static ssize_t show_in(struct device *dev, struct device_attribute *da,
> > ads7828_lsb_resol)/1000);
>
> Can you fix this one as well since you are at it ? There is another one in sensors_ads7828_init().
> [ Wonder why checkpatch doesn't complain about it ]
Sure.
>
> > }
> >
> > -#define in_reg(offset)\
> > -static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO, show_in,\
> > - NULL, offset)
> > +#define in_reg(offset) \
> > +static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO, show_in, NULL, offset)
> >
> This causes a checkpatch error - checkpatch doesn't like the multi-line macros.
My bad, I'm on a 2.6.37 box, I didn't checkout the upstream version of
checkpatch.pl too.
>
> > in_reg(0);
> > in_reg(1);
>
> Since it seems to be hardly worth it anyway (yes, I know there are 8 of them),
> would be great if you can just get rid of the macro and just use
> static SENSOR_DEVICE_ATTR(in[1-8]_input, ...)
> instead.
Ok.
>
> > @@ -158,25 +156,6 @@ static int ads7828_remove(struct i2c_client *client)
> > return 0;
> > }
> >
> > -static const struct i2c_device_id ads7828_id[] = {
> > - { "ads7828", 0 },
> > - { }
> > -};
> > -MODULE_DEVICE_TABLE(i2c, ads7828_id);
> > -
> > -/* This is the driver that will be inserted */
> > -static struct i2c_driver ads7828_driver = {
> > - .class = I2C_CLASS_HWMON,
> > - .driver = {
> > - .name = "ads7828",
> > - },
> > - .probe = ads7828_probe,
> > - .remove = ads7828_remove,
> > - .id_table = ads7828_id,
> > - .detect = ads7828_detect,
> > - .address_list = normal_i2c,
> > -};
> > -
> > /* Return 0 if detection is successful, -ENODEV otherwise */
> > static int ads7828_detect(struct i2c_client *client,
> > struct i2c_board_info *info)
> > @@ -247,13 +226,29 @@ exit:
> > return err;
> > }
> >
> > +static const struct i2c_device_id ads7828_ids[] = {
> > + { "ads7828", 0 },
> > + { }
> > +};
> > +MODULE_DEVICE_TABLE(i2c, ads7828_ids);
> > +
> > +static struct i2c_driver ads7828_driver = {
> > + .class = I2C_CLASS_HWMON,
> > + .driver = {
> > + .name = "ads7828",
> > + },
> > + .address_list = normal_i2c,
> > + .detect = ads7828_detect,
> > + .probe = ads7828_probe,
> > + .remove = ads7828_remove,
> > + .id_table = ads7828_ids,
> > +};
> > +
> > static int __init sensors_ads7828_init(void)
> > {
> > /* Initialize the command byte according to module parameters */
> > - ads7828_cmd_byte = se_input ?
> > - ADS7828_CMD_SD_SE : ADS7828_CMD_SD_DIFF;
> > - ads7828_cmd_byte |= int_vref ?
> > - ADS7828_CMD_PD3 : ADS7828_CMD_PD1;
> > + ads7828_cmd_byte = se_input ? ADS7828_CMD_SD_SE : ADS7828_CMD_SD_DIFF;
> > + ads7828_cmd_byte |= int_vref ? ADS7828_CMD_PD3 : ADS7828_CMD_PD1;
> >
> > /* Calculate the LSB resolution */
> > ads7828_lsb_resol = (vref_mv*1000)/4096;
> > @@ -267,7 +262,7 @@ static void __exit sensors_ads7828_exit(void)
> > }
> >
> > MODULE_AUTHOR("Steve Hardy <shardy@redhat.com>");
> > -MODULE_DESCRIPTION("ADS7828 driver");
> > +MODULE_DESCRIPTION("Driver for TI ADS7828 A/D converter");
> > MODULE_LICENSE("GPL");
> >
> > module_init(sensors_ads7828_init);
> > --
> > 1.7.11.4
> >
> >

Thanks for your comments,
Vivien