On Wed, Dec 21, 2011 at 10:36 PM, Jérôme Carretero cJ-uboot@zougloub.eu wrote:

Hi Tom,

I'm requesting comments on the following (untested) patch. It adds support for multiple i2c buses on davinci_i2c, without altering one line of code. What I don't like is that I'm doing a bit of macro black magic to transform constants into variables. But I don't know whether refactoring the code would be accepted, so this is a first shot.

So, this follows the example of other i2c drivers, but as Wolfgang likes to point out, following another bad example isn't a valid reason to do something. So, is this the right way or a bad example to follow, Wolfgang or Heiko? Thanks!

Regards,

-- cJ

commit 53d99d331dc7fc4bf3384a59bbca564bf1b85f6b Author: Jerome Carretero cJ-uboot@zougloub.eu Date:   Thu Dec 22 00:26:13 2011 -0500

DaVinci/i2c: Support for multiple buses

diff --git a/arch/arm/include/asm/arch-davinci/i2c_defs.h b/arch/arm/include/asm/arch-davinci/i2c_defs.h index 24cd268..1d24fbf 100644 --- a/arch/arm/include/asm/arch-davinci/i2c_defs.h +++ b/arch/arm/include/asm/arch-davinci/i2c_defs.h @@ -25,13 +25,18 @@  #ifndef _DAVINCI_I2C_H_  #define _DAVINCI_I2C_H_

+#include <asm/arch/hardware.h>

#define I2C_WRITE              0  #define I2C_READ               1

#ifndef CONFIG_SOC_DA8XX -#define I2C_BASE               0x01c21000 +# define I2C_BASE              DAVINCI_I2C_BASE +# define I2C_DEFAULT_BASE I2C_BASE  #else -#define I2C_BASE               0x01c22000 +# define I2C_BASE0             DAVINCI_I2C0_BASE +# define I2C_BASE1             DAVINCI_I2C1_BASE +# define I2C_DEFAULT_BASE I2C_BASE0  #endif

#define        I2C_OA                  (I2C_BASE + 0x00) diff --git a/drivers/i2c/davinci_i2c.c b/drivers/i2c/davinci_i2c.c index 2abddfb..be7fb7a 100644 --- a/drivers/i2c/davinci_i2c.c +++ b/drivers/i2c/davinci_i2c.c @@ -29,6 +29,44 @@  #include <asm/arch/hardware.h>  #include <asm/arch/i2c_defs.h>

+#if defined(CONFIG_I2C_MULTI_BUS)

+static unsigned int bus_initialized[I2C_BUS_MAX]; +static unsigned int current_bus; +static unsigned long i2c_base = I2C_DEFAULT_BASE;

+#ifndef I2C_BASE +# define I2C_BASE i2c_base +#else +# error CONFIG_I2C_MULTI_BUS *and* I2C_BASE defined ! +#endif

+int i2c_set_bus_num(unsigned int bus) +{

• if ((bus < 0) || (bus >= I2C_BUS_MAX)) { // TODO where to put I2C_BUS_MAX ?
• printf("Bad bus: %d\n", bus);
• return -1;
• }
• if (bus == 1)
• i2c_base = I2C_BASE1;
• else
• i2c_base = I2C_BASE0;
• current_bus = bus;
• if (!bus_initialized[current_bus])
• i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
• return 0;

+}

+unsigned int i2c_get_bus_num(void) +{

• return current_bus;

+}

+#endif

#define CHECK_NACK() \        do {\                if (tmp & (I2C_TIMEOUT | I2C_STAT_NACK)) {\