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

[Vivien Didelot]

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@xxxxxxxxxxxxxxxxxxxx>
> 
> 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@xxxxxxxxxx>
> >   *
> > - * 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@xxxxxxxxxx>");
> > -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

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