ARMV7: OMAP3: Add expansion board detection for Overo

Overo expansion boards contain an i2c eeprom to identify themselves.
This patch adds code to read and parse the eeprom contents.  It prints
the expansion board name and revision and modifies environment variables
as appropriate.

Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>

board/overo/overo.c

@@ -40,6 +40,32 @@
 #include <asm/mach-types.h>
 #include "overo.h"
 
+#define TWL4030_I2C_BUS			0
+#define EXPANSION_EEPROM_I2C_BUS	2
+#define EXPANSION_EEPROM_I2C_ADDRESS	0x51
+
+#define GUMSTIX_SUMMIT			0x01000200
+#define GUMSTIX_TOBI			0x02000200
+#define GUMSTIX_TOBI_DUO		0x03000200
+#define GUMSTIX_PALO35			0x04000200
+#define GUMSTIX_PALO43			0x05000200
+#define GUMSTIX_CHESTNUT43		0x06000200
+#define GUMSTIX_PINTO			0x07000200
+#define GUMSTIX_GALLOP43		0x08000200
+
+#define ETTUS_USRP_E			0x01000300
+
+#define GUMSTIX_NO_EEPROM		0xffffffff
+
+static struct {
+	unsigned int device_vendor;
+	unsigned char revision;
+	unsigned char content;
+	char fab_revision[8];
+	char env_var[16];
+	char env_setting[64];
+} expansion_config;
+
 #if defined(CONFIG_CMD_NET)
 static void setup_net_chip(void);
 #endif
@@ -136,6 +162,31 @@ int get_sdio2_config(void)
 	return sdio_direct;
 }
 
+/*
+ * Routine: get_expansion_id
+ * Description: This function checks for expansion board by checking I2C
+ *		bus 2 for the availability of an AT24C01B serial EEPROM.
+ *		returns the device_vendor field from the EEPROM
+ */
+unsigned int get_expansion_id(void)
+{
+	i2c_set_bus_num(EXPANSION_EEPROM_I2C_BUS);
+
+	/* return GUMSTIX_NO_EEPROM if eeprom doesn't respond */
+	if (i2c_probe(EXPANSION_EEPROM_I2C_ADDRESS) == 1) {
+		i2c_set_bus_num(TWL4030_I2C_BUS);
+		return GUMSTIX_NO_EEPROM;
+	}
+
+	/* read configuration data */
+	i2c_read(EXPANSION_EEPROM_I2C_ADDRESS, 0, 1, (u8 *)&expansion_config,
+		 sizeof(expansion_config));
+
+	i2c_set_bus_num(TWL4030_I2C_BUS);
+
+	return expansion_config.device_vendor;
+}
+
 /*
  * Routine: misc_init_r
  * Description: Configure board specific parts
@@ -164,6 +215,70 @@ int misc_init_r(void)
 		printf("Unable to detect mmc2 connection type\n");
 	}
 
+	switch (get_expansion_id()) {
+	case GUMSTIX_SUMMIT:
+		printf("Recognized Summit expansion board (rev %d %s)\n",
+			expansion_config.revision,
+			expansion_config.fab_revision);
+		setenv("defaultdisplay", "dvi");
+		break;
+	case GUMSTIX_TOBI:
+		printf("Recognized Tobi expansion board (rev %d %s)\n",
+			expansion_config.revision,
+			expansion_config.fab_revision);
+		setenv("defaultdisplay", "dvi");
+		break;
+	case GUMSTIX_TOBI_DUO:
+		printf("Recognized Tobi Duo expansion board (rev %d %s)\n",
+			expansion_config.revision,
+			expansion_config.fab_revision);
+		break;
+	case GUMSTIX_PALO35:
+		printf("Recognized Palo35 expansion board (rev %d %s)\n",
+			expansion_config.revision,
+			expansion_config.fab_revision);
+		setenv("defaultdisplay", "lcd35");
+		break;
+	case GUMSTIX_PALO43:
+		printf("Recognized Palo43 expansion board (rev %d %s)\n",
+			expansion_config.revision,
+			expansion_config.fab_revision);
+		setenv("defaultdisplay", "lcd43");
+		break;
+	case GUMSTIX_CHESTNUT43:
+		printf("Recognized Chestnut43 expansion board (rev %d %s)\n",
+			expansion_config.revision,
+			expansion_config.fab_revision);
+		setenv("defaultdisplay", "lcd43");
+		break;
+	case GUMSTIX_PINTO:
+		printf("Recognized Pinto expansion board (rev %d %s)\n",
+			expansion_config.revision,
+			expansion_config.fab_revision);
+		break;
+	case GUMSTIX_GALLOP43:
+		printf("Recognized Gallop43 expansion board (rev %d %s)\n",
+			expansion_config.revision,
+			expansion_config.fab_revision);
+		setenv("defaultdisplay", "lcd43");
+		break;
+	case ETTUS_USRP_E:
+		printf("Recognized Ettus Research USRP-E (rev %d %s)\n",
+			expansion_config.revision,
+			expansion_config.fab_revision);
+		MUX_USRP_E();
+		setenv("defaultdisplay", "dvi");
+		break;
+	case GUMSTIX_NO_EEPROM:
+		printf("No EEPROM on expansion board\n");
+		break;
+	default:
+		printf("Unrecognized expansion board\n");
+	}
+
+	if (expansion_config.content == 1)
+		setenv(expansion_config.env_var, expansion_config.env_setting);
+
 	dieid_num_r();
 
 	return 0;

board/overo/overo.h

@@ -419,4 +419,8 @@ const omap3_sysinfo sysinfo = {
 	MUX_VAL(CP(MMC1_DAT6),		(IEN  | PTU | EN  | M4)) /*GPIO_128*/\
 	MUX_VAL(CP(MMC1_DAT7),		(IEN  | PTU | EN  | M4)) /*GPIO_129*/
 
+#define MUX_USRP_E() \
+	MUX_VAL(CP(MCSPI1_SOMI),	(IEN  | PTD | DIS | M4)) /*GPIO_173 */\
+	MUX_VAL(CP(MCSPI1_CS1),		(IDIS | PTD | EN  | M4)) /*GPIO_175 */\
+
 #endif

include/configs/omap3_overo.h

@@ -119,6 +119,7 @@
 #define CONFIG_SYS_I2C_SLAVE		1
 #define CONFIG_SYS_I2C_BUS		0
 #define CONFIG_SYS_I2C_BUS_SELECT	1
+#define CONFIG_I2C_MULTI_BUS		1
 #define CONFIG_DRIVER_OMAP34XX_I2C	1
 
 /*