[U-Boot] PATCH 2/8 Multi-adapter multi-bus I2C

[ksi at koi8.net]

On Mon, 9 Feb 2009, Heiko Schocher wrote:

> Hello ksi,
> 
> ksi at koi8.net wrote:
> [...]
> > diff --git a/drivers/i2c/fsl_i2c.c b/drivers/i2c/fsl_i2c.c
> > index ce646fd..f7998e3 100644
> > --- a/drivers/i2c/fsl_i2c.c
> > +++ b/drivers/i2c/fsl_i2c.c
> > @@ -1,4 +1,8 @@
> >  /*
> > + * Copyright (c) 2009 Sergey Kubushyn <ksi at koi8.net>
> > + *
> > + * Changes for multibus/multiadapter I2C support.
> > + *
> >   * Copyright 2006 Freescale Semiconductor, Inc.
> >   *
> >   * This program is free software; you can redistribute it and/or
> > @@ -18,7 +22,7 @@
> >  
> >  #include <common.h>
> >  
> > -#ifdef CONFIG_HARD_I2C
> > +#ifdef CONFIG_FSL_I2C
> >  
> >  #include <command.h>
> >  #include <i2c.h>		/* Functional interface */
> > @@ -31,24 +35,15 @@
> >  #define I2C_READ_BIT  1
> >  #define I2C_WRITE_BIT 0
> >  
> > -DECLARE_GLOBAL_DATA_PTR;
> > -
> > -/* Initialize the bus pointer to whatever one the SPD EEPROM is on.
> > - * Default is bus 0.  This is necessary because the DDR initialization
> > - * runs from ROM, and we can't switch buses because we can't modify
> > - * the global variables.
> > - */
> > -#ifndef CONFIG_SYS_SPD_BUS_NUM
> > -#define CONFIG_SYS_SPD_BUS_NUM 0
> > -#endif
> > -static unsigned int i2c_bus_num __attribute__ ((section (".data"))) = CONFIG_SYS_SPD_BUS_NUM;
> > +#define FSL_NAME(arg)	"fsl_i2c@" MK_NAME(arg)
> > +#define MK_NAME(arg)	#arg
> >  
> > -static unsigned int i2c_bus_speed[2] = {CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SPEED};
> > +DECLARE_GLOBAL_DATA_PTR;
> >  
> >  static const struct fsl_i2c *i2c_dev[2] = {
> > -	(struct fsl_i2c *) (CONFIG_SYS_IMMR + CONFIG_SYS_I2C_OFFSET),
> > -#ifdef CONFIG_SYS_I2C2_OFFSET
> > -	(struct fsl_i2c *) (CONFIG_SYS_IMMR + CONFIG_SYS_I2C2_OFFSET)
> > +	(struct fsl_i2c *) (CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C_OFFSET),
> > +#ifdef CONFIG_SYS_FSL_I2C2_OFFSET
> > +	(struct fsl_i2c *) (CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C2_OFFSET)
> >  #endif
> >  };
> >  
> > @@ -126,6 +121,8 @@ static const struct {
> >  #endif
> >  };
> >  
> > +i2c_adap_t	fsl_i2c_adap[];
> > +
> >  /**
> >   * Set the I2C bus speed for a given I2C device
> >   *
> > @@ -169,43 +166,29 @@ static unsigned int set_i2c_bus_speed(const struct fsl_i2c *dev,
> >  	return speed;
> >  }
> >  
> > -void
> > -i2c_init(int speed, int slaveadd)
> > +
> > +static void __i2c_init(int adap_no, int speed, int slaveadd)
> >  {
> > -	struct fsl_i2c *dev;
> >  	unsigned int temp;
> >  
> > -	dev = (struct fsl_i2c *) (CONFIG_SYS_IMMR + CONFIG_SYS_I2C_OFFSET);
> > -
> > -	writeb(0, &dev->cr);			/* stop I2C controller */
> > +	writeb(0, &i2c_dev[adap_no]->cr);	/* stop I2C controller */
> >   
> 
> Why do you here substitute a "dev->" with "&i2c_dev[adap_no]"?
> Why not dev =  &i2c_dev[adap_no] and you can let the dev-> unchanged.

This eliminates one variable, dev. Another reason is uniformity through the
entire driver source.

Anyway, keeping that dev won't make any difference other than making the
patch a tad shorter...

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