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)) {\