[ARM] 4650/1: AT91: New-style init of I2C, support for i2c-gpio

The AT91 I2C driver is currently marked as "broken" due to hardware
issues.  This patch enables AT91-based platforms to also use the
bitbanged GPIO for I2C.

This updates platform setup logic (setting up an i2c-gpio device
using the same pins as the i2c-at91 device, unless only the BROKEN
driver is enabled).

Also make use of the new-style initialization of I2C devices using
i2c_register_board_info().

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-at91/at91rm9200_devices.c

@@ -14,6 +14,7 @@
 #include <asm/mach/map.h>
 
 #include <linux/platform_device.h>
+#include <linux/i2c-gpio.h>
 
 #include <asm/arch/board.h>
 #include <asm/arch/gpio.h>
@@ -435,7 +436,40 @@ void __init at91_add_device_nand(struct at91_nand_data *data) {}
  *  TWI (i2c)
  * -------------------------------------------------------------------- */
 
-#if defined(CONFIG_I2C_AT91) || defined(CONFIG_I2C_AT91_MODULE)
+/*
+ * Prefer the GPIO code since the TWI controller isn't robust
+ * (gets overruns and underruns under load) and can only issue
+ * repeated STARTs in one scenario (the driver doesn't yet handle them).
+ */
+#if defined(CONFIG_I2C_GPIO) || defined(CONFIG_I2C_GPIO_MODULE)
+
+static struct i2c_gpio_platform_data pdata = {
+	.sda_pin		= AT91_PIN_PA25,
+	.sda_is_open_drain	= 1,
+	.scl_pin		= AT91_PIN_PA26,
+	.scl_is_open_drain	= 1,
+	.udelay			= 2,		/* ~100 kHz */
+};
+
+static struct platform_device at91rm9200_twi_device = {
+	.name			= "i2c-gpio",
+	.id			= -1,
+	.dev.platform_data	= &pdata,
+};
+
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices)
+{
+	at91_set_GPIO_periph(AT91_PIN_PA25, 1);		/* TWD (SDA) */
+	at91_set_multi_drive(AT91_PIN_PA25, 1);
+
+	at91_set_GPIO_periph(AT91_PIN_PA26, 1);		/* TWCK (SCL) */
+	at91_set_multi_drive(AT91_PIN_PA26, 1);
+
+	i2c_register_board_info(0, devices, nr_devices);
+	platform_device_register(&at91rm9200_twi_device);
+}
+
+#elif defined(CONFIG_I2C_AT91) || defined(CONFIG_I2C_AT91_MODULE)
 
 static struct resource twi_resources[] = {
 	[0] = {
@@ -457,7 +491,7 @@ static struct platform_device at91rm9200_twi_device = {
 	.num_resources	= ARRAY_SIZE(twi_resources),
 };
 
-void __init at91_add_device_i2c(void)
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices)
 {
 	/* pins used for TWI interface */
 	at91_set_A_periph(AT91_PIN_PA25, 0);		/* TWD */
@@ -466,10 +500,11 @@ void __init at91_add_device_i2c(void)
 	at91_set_A_periph(AT91_PIN_PA26, 0);		/* TWCK */
 	at91_set_multi_drive(AT91_PIN_PA26, 1);
 
+	i2c_register_board_info(0, devices, nr_devices);
 	platform_device_register(&at91rm9200_twi_device);
 }
 #else
-void __init at91_add_device_i2c(void) {}
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices) {}
 #endif
 
 

arch/arm/mach-at91/at91sam9260_devices.c

@@ -13,6 +13,7 @@
 #include <asm/mach/map.h>
 
 #include <linux/platform_device.h>
+#include <linux/i2c-gpio.h>
 
 #include <asm/arch/board.h>
 #include <asm/arch/gpio.h>
@@ -352,7 +353,41 @@ void __init at91_add_device_nand(struct at91_nand_data *data) {}
  *  TWI (i2c)
  * -------------------------------------------------------------------- */
 
-#if defined(CONFIG_I2C_AT91) || defined(CONFIG_I2C_AT91_MODULE)
+/*
+ * Prefer the GPIO code since the TWI controller isn't robust
+ * (gets overruns and underruns under load) and can only issue
+ * repeated STARTs in one scenario (the driver doesn't yet handle them).
+ */
+
+#if defined(CONFIG_I2C_GPIO) || defined(CONFIG_I2C_GPIO_MODULE)
+
+static struct i2c_gpio_platform_data pdata = {
+	.sda_pin		= AT91_PIN_PA23,
+	.sda_is_open_drain	= 1,
+	.scl_pin		= AT91_PIN_PA24,
+	.scl_is_open_drain	= 1,
+	.udelay			= 2,		/* ~100 kHz */
+};
+
+static struct platform_device at91sam9260_twi_device = {
+	.name			= "i2c-gpio",
+	.id			= -1,
+	.dev.platform_data	= &pdata,
+};
+
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices)
+{
+	at91_set_GPIO_periph(AT91_PIN_PA23, 1);		/* TWD (SDA) */
+	at91_set_multi_drive(AT91_PIN_PA23, 1);
+
+	at91_set_GPIO_periph(AT91_PIN_PA24, 1);		/* TWCK (SCL) */
+	at91_set_multi_drive(AT91_PIN_PA24, 1);
+
+	i2c_register_board_info(0, devices, nr_devices);
+	platform_device_register(&at91sam9260_twi_device);
+}
+
+#elif defined(CONFIG_I2C_AT91) || defined(CONFIG_I2C_AT91_MODULE)
 
 static struct resource twi_resources[] = {
 	[0] = {
@@ -374,7 +409,7 @@ static struct platform_device at91sam9260_twi_device = {
 	.num_resources	= ARRAY_SIZE(twi_resources),
 };
 
-void __init at91_add_device_i2c(void)
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices)
 {
 	/* pins used for TWI interface */
 	at91_set_A_periph(AT91_PIN_PA23, 0);		/* TWD */
@@ -383,10 +418,11 @@ void __init at91_add_device_i2c(void)
 	at91_set_A_periph(AT91_PIN_PA24, 0);		/* TWCK */
 	at91_set_multi_drive(AT91_PIN_PA24, 1);
 
+	i2c_register_board_info(0, devices, nr_devices);
 	platform_device_register(&at91sam9260_twi_device);
 }
 #else
-void __init at91_add_device_i2c(void) {}
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices) {}
 #endif
 
 

arch/arm/mach-at91/at91sam9261_devices.c

@@ -14,7 +14,9 @@
 #include <asm/mach/map.h>
 
 #include <linux/platform_device.h>
+#include <linux/i2c-gpio.h>
 
+#include <linux/fb.h>
 #include <video/atmel_lcdc.h>
 
 #include <asm/arch/board.h>
@@ -275,7 +277,40 @@ void __init at91_add_device_nand(struct at91_nand_data *data) {}
  *  TWI (i2c)
  * -------------------------------------------------------------------- */
 
-#if defined(CONFIG_I2C_AT91) || defined(CONFIG_I2C_AT91_MODULE)
+/*
+ * Prefer the GPIO code since the TWI controller isn't robust
+ * (gets overruns and underruns under load) and can only issue
+ * repeated STARTs in one scenario (the driver doesn't yet handle them).
+ */
+#if defined(CONFIG_I2C_GPIO) || defined(CONFIG_I2C_GPIO_MODULE)
+
+static struct i2c_gpio_platform_data pdata = {
+	.sda_pin		= AT91_PIN_PA7,
+	.sda_is_open_drain	= 1,
+	.scl_pin		= AT91_PIN_PA8,
+	.scl_is_open_drain	= 1,
+	.udelay			= 2,		/* ~100 kHz */
+};
+
+static struct platform_device at91sam9261_twi_device = {
+	.name			= "i2c-gpio",
+	.id			= -1,
+	.dev.platform_data	= &pdata,
+};
+
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices)
+{
+	at91_set_GPIO_periph(AT91_PIN_PA7, 1);		/* TWD (SDA) */
+	at91_set_multi_drive(AT91_PIN_PA7, 1);
+
+	at91_set_GPIO_periph(AT91_PIN_PA8, 1);		/* TWCK (SCL) */
+	at91_set_multi_drive(AT91_PIN_PA8, 1);
+
+	i2c_register_board_info(0, devices, nr_devices);
+	platform_device_register(&at91sam9261_twi_device);
+}
+
+#elif defined(CONFIG_I2C_AT91) || defined(CONFIG_I2C_AT91_MODULE)
 
 static struct resource twi_resources[] = {
 	[0] = {
@@ -297,7 +332,7 @@ static struct platform_device at91sam9261_twi_device = {
 	.num_resources	= ARRAY_SIZE(twi_resources),
 };
 
-void __init at91_add_device_i2c(void)
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices)
 {
 	/* pins used for TWI interface */
 	at91_set_A_periph(AT91_PIN_PA7, 0);		/* TWD */
@@ -306,10 +341,11 @@ void __init at91_add_device_i2c(void)
 	at91_set_A_periph(AT91_PIN_PA8, 0);		/* TWCK */
 	at91_set_multi_drive(AT91_PIN_PA8, 1);
 
+	i2c_register_board_info(0, devices, nr_devices);
 	platform_device_register(&at91sam9261_twi_device);
 }
 #else
-void __init at91_add_device_i2c(void) {}
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices) {}
 #endif
 
 

arch/arm/mach-at91/at91sam9263_devices.c

@@ -13,7 +13,9 @@
 #include <asm/mach/map.h>
 
 #include <linux/platform_device.h>
+#include <linux/i2c-gpio.h>
 
+#include <linux/fb.h>
 #include <video/atmel_lcdc.h>
 
 #include <asm/arch/board.h>
@@ -421,7 +423,40 @@ void __init at91_add_device_nand(struct at91_nand_data *data) {}
  *  TWI (i2c)
  * -------------------------------------------------------------------- */
 
-#if defined(CONFIG_I2C_AT91) || defined(CONFIG_I2C_AT91_MODULE)
+/*
+ * Prefer the GPIO code since the TWI controller isn't robust
+ * (gets overruns and underruns under load) and can only issue
+ * repeated STARTs in one scenario (the driver doesn't yet handle them).
+ */
+#if defined(CONFIG_I2C_GPIO) || defined(CONFIG_I2C_GPIO_MODULE)
+
+static struct i2c_gpio_platform_data pdata = {
+	.sda_pin		= AT91_PIN_PB4,
+	.sda_is_open_drain	= 1,
+	.scl_pin		= AT91_PIN_PB5,
+	.scl_is_open_drain	= 1,
+	.udelay			= 2,		/* ~100 kHz */
+};
+
+static struct platform_device at91sam9263_twi_device = {
+	.name			= "i2c-gpio",
+	.id			= -1,
+	.dev.platform_data	= &pdata,
+};
+
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices)
+{
+	at91_set_GPIO_periph(AT91_PIN_PB4, 1);		/* TWD (SDA) */
+	at91_set_multi_drive(AT91_PIN_PB4, 1);
+
+	at91_set_GPIO_periph(AT91_PIN_PB5, 1);		/* TWCK (SCL) */
+	at91_set_multi_drive(AT91_PIN_PB5, 1);
+
+	i2c_register_board_info(0, devices, nr_devices);
+	platform_device_register(&at91sam9263_twi_device);
+}
+
+#elif defined(CONFIG_I2C_AT91) || defined(CONFIG_I2C_AT91_MODULE)
 
 static struct resource twi_resources[] = {
 	[0] = {
@@ -443,7 +478,7 @@ static struct platform_device at91sam9263_twi_device = {
 	.num_resources	= ARRAY_SIZE(twi_resources),
 };
 
-void __init at91_add_device_i2c(void)
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices)
 {
 	/* pins used for TWI interface */
 	at91_set_A_periph(AT91_PIN_PB4, 0);		/* TWD */
@@ -452,10 +487,11 @@ void __init at91_add_device_i2c(void)
 	at91_set_A_periph(AT91_PIN_PB5, 0);		/* TWCK */
 	at91_set_multi_drive(AT91_PIN_PB5, 1);
 
+	i2c_register_board_info(0, devices, nr_devices);
 	platform_device_register(&at91sam9263_twi_device);
 }
 #else
-void __init at91_add_device_i2c(void) {}
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices) {}
 #endif
 
 

arch/arm/mach-at91/at91sam9rl_devices.c

@@ -10,8 +10,9 @@
 #include <asm/mach/map.h>
 
 #include <linux/platform_device.h>
-#include <linux/fb.h>
+#include <linux/i2c-gpio.h>
 
+#include <linux/fb.h>
 #include <video/atmel_lcdc.h>
 
 #include <asm/arch/board.h>
@@ -169,7 +170,40 @@ void __init at91_add_device_nand(struct at91_nand_data *data) {}
  *  TWI (i2c)
  * -------------------------------------------------------------------- */
 
-#if defined(CONFIG_I2C_AT91) || defined(CONFIG_I2C_AT91_MODULE)
+/*
+ * Prefer the GPIO code since the TWI controller isn't robust
+ * (gets overruns and underruns under load) and can only issue
+ * repeated STARTs in one scenario (the driver doesn't yet handle them).
+ */
+#if defined(CONFIG_I2C_GPIO) || defined(CONFIG_I2C_GPIO_MODULE)
+
+static struct i2c_gpio_platform_data pdata = {
+	.sda_pin		= AT91_PIN_PA23,
+	.sda_is_open_drain	= 1,
+	.scl_pin		= AT91_PIN_PA24,
+	.scl_is_open_drain	= 1,
+	.udelay			= 2,		/* ~100 kHz */
+};
+
+static struct platform_device at91sam9rl_twi_device = {
+	.name			= "i2c-gpio",
+	.id			= -1,
+	.dev.platform_data	= &pdata,
+};
+
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices)
+{
+	at91_set_GPIO_periph(AT91_PIN_PA23, 1);		/* TWD (SDA) */
+	at91_set_multi_drive(AT91_PIN_PA23, 1);
+
+	at91_set_GPIO_periph(AT91_PIN_PA24, 1);		/* TWCK (SCL) */
+	at91_set_multi_drive(AT91_PIN_PA24, 1);
+
+	i2c_register_board_info(0, devices, nr_devices);
+	platform_device_register(&at91sam9rl_twi_device);
+}
+
+#elif defined(CONFIG_I2C_AT91) || defined(CONFIG_I2C_AT91_MODULE)
 
 static struct resource twi_resources[] = {
 	[0] = {
@@ -191,7 +225,7 @@ static struct platform_device at91sam9rl_twi_device = {
 	.num_resources	= ARRAY_SIZE(twi_resources),
 };
 
-void __init at91_add_device_i2c(void)
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices)
 {
 	/* pins used for TWI interface */
 	at91_set_A_periph(AT91_PIN_PA23, 0);		/* TWD */
@@ -200,10 +234,11 @@ void __init at91_add_device_i2c(void)
 	at91_set_A_periph(AT91_PIN_PA24, 0);		/* TWCK */
 	at91_set_multi_drive(AT91_PIN_PA24, 1);
 
+	i2c_register_board_info(0, devices, nr_devices);
 	platform_device_register(&at91sam9rl_twi_device);
 }
 #else
-void __init at91_add_device_i2c(void) {}
+void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices) {}
 #endif
 
 

arch/arm/mach-at91/board-carmeva.c

@@ -128,7 +128,7 @@ static void __init carmeva_board_init(void)
 	/* USB Device */
 	at91_add_device_udc(&carmeva_udc_data);
 	/* I2C */
-	at91_add_device_i2c();
+	at91_add_device_i2c(NULL, 0);
 	/* SPI */
 	at91_add_device_spi(carmeva_spi_devices, ARRAY_SIZE(carmeva_spi_devices));
 	/* Compact Flash */

arch/arm/mach-at91/board-csb337.c

@@ -23,7 +23,6 @@
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
-#include <linux/i2c.h>
 #include <linux/spi/spi.h>
 #include <linux/mtd/physmap.h>
 
@@ -85,12 +84,12 @@ static struct at91_udc_data __initdata csb337_udc_data = {
 };
 
 static struct i2c_board_info __initdata csb337_i2c_devices[] = {
-	{ I2C_BOARD_INFO("rtc-ds1307", 0x68),
-	  .type = "ds1307",
+	{
+		I2C_BOARD_INFO("rtc-ds1307", 0x68),
+		.type	= "ds1307",
 	},
 };
 
-
 static struct at91_cf_data __initdata csb337_cf_data = {
 	/*
 	 * connector P4 on the CSB 337 mates to
@@ -168,9 +167,7 @@ static void __init csb337_board_init(void)
 	/* USB Device */
 	at91_add_device_udc(&csb337_udc_data);
 	/* I2C */
-	at91_add_device_i2c();
-	i2c_register_board_info(0, csb337_i2c_devices,
-			ARRAY_SIZE(csb337_i2c_devices));
+	at91_add_device_i2c(csb337_i2c_devices, ARRAY_SIZE(csb337_i2c_devices));
 	/* Compact Flash */
 	at91_set_gpio_input(AT91_PIN_PB22, 1);		/* IOIS16 */
 	at91_add_device_cf(&csb337_cf_data);

arch/arm/mach-at91/board-csb637.c

@@ -129,7 +129,7 @@ static void __init csb637_board_init(void)
 	/* USB Device */
 	at91_add_device_udc(&csb637_udc_data);
 	/* I2C */
-	at91_add_device_i2c();
+	at91_add_device_i2c(NULL, 0);
 	/* SPI */
 	at91_add_device_spi(NULL, 0);
 	/* NOR flash */

arch/arm/mach-at91/board-dk.c

@@ -124,6 +124,19 @@ static struct spi_board_info dk_spi_devices[] = {
 #endif
 };
 
+static struct i2c_board_info __initdata dk_i2c_devices[] = {
+	{
+		I2C_BOARD_INFO("ics1523", 0x26),
+	},
+	{
+		I2C_BOARD_INFO("x9429", 0x28),
+	},
+	{
+		I2C_BOARD_INFO("at24c", 0x50),
+		.type	= "24c1024",
+	}
+};
+
 static struct mtd_partition __initdata dk_nand_partition[] = {
 	{
 		.name	= "NAND Partition 1",
@@ -185,7 +198,7 @@ static void __init dk_board_init(void)
 	/* Compact Flash */
 	at91_add_device_cf(&dk_cf_data);
 	/* I2C */
-	at91_add_device_i2c();
+	at91_add_device_i2c(dk_i2c_devices, ARRAY_SIZE(dk_i2c_devices));
 	/* SPI */
 	at91_add_device_spi(dk_spi_devices, ARRAY_SIZE(dk_spi_devices));
 #ifdef CONFIG_MTD_AT91_DATAFLASH_CARD

arch/arm/mach-at91/board-eb9200.c

@@ -91,6 +91,14 @@ static struct at91_mmc_data __initdata eb9200_mmc_data = {
 	.wire4		= 1,
 };
 
+static struct i2c_board_info __initdata eb9200_i2c_devices[] = {
+	{
+		I2C_BOARD_INFO("at24c", 0x50),
+		.type	= "24c512",
+	},
+};
+
+
 static void __init eb9200_board_init(void)
 {
 	/* Serial */
@@ -102,7 +110,7 @@ static void __init eb9200_board_init(void)
 	/* USB Device */
 	at91_add_device_udc(&eb9200_udc_data);
 	/* I2C */
-	at91_add_device_i2c();
+	at91_add_device_i2c(eb9200_i2c_devices, ARRAY_SIZE(eb9200_i2c_devices));
 	/* Compact Flash */
 	at91_add_device_cf(&eb9200_cf_data);
 	/* SPI */

arch/arm/mach-at91/board-ek.c

@@ -145,7 +145,7 @@ static void __init ek_board_init(void)
 	at91_add_device_udc(&ek_udc_data);
 	at91_set_multi_drive(ek_udc_data.pullup_pin, 1);	/* pullup_pin is connected to reset */
 	/* I2C */
-	at91_add_device_i2c();
+	at91_add_device_i2c(ek_i2c_devices, ARRAY_SIZE(ek_i2c_devices));
 	/* SPI */
 	at91_add_device_spi(ek_spi_devices, ARRAY_SIZE(ek_spi_devices));
 #ifdef CONFIG_MTD_AT91_DATAFLASH_CARD

arch/arm/mach-at91/board-kafa.c

@@ -92,7 +92,7 @@ static void __init kafa_board_init(void)
 	/* USB Device */
 	at91_add_device_udc(&kafa_udc_data);
 	/* I2C */
-	at91_add_device_i2c();
+	at91_add_device_i2c(NULL, 0);
 	/* SPI */
 	at91_add_device_spi(NULL, 0);
 }

arch/arm/mach-at91/board-kb9202.c

@@ -124,7 +124,7 @@ static void __init kb9202_board_init(void)
 	/* MMC */
 	at91_add_device_mmc(0, &kb9202_mmc_data);
 	/* I2C */
-	at91_add_device_i2c();
+	at91_add_device_i2c(NULL, 0);
 	/* SPI */
 	at91_add_device_spi(NULL, 0);
 	/* NAND */

arch/arm/mach-at91/board-picotux200.c

@@ -139,7 +139,7 @@ static void __init picotux200_board_init(void)
 	// at91_add_device_udc(&picotux200_udc_data);
 	// at91_set_multi_drive(picotux200_udc_data.pullup_pin, 1);	/* pullup_pin is connected to reset */
 	/* I2C */
-	at91_add_device_i2c();
+	at91_add_device_i2c(NULL, 0);
 	/* SPI */
 	// at91_add_device_spi(picotux200_spi_devices, ARRAY_SIZE(picotux200_spi_devices));
 #ifdef CONFIG_MTD_AT91_DATAFLASH_CARD

arch/arm/mach-at91/board-sam9260ek.c

@@ -189,7 +189,7 @@ static void __init ek_board_init(void)
 	/* MMC */
 	at91_add_device_mmc(0, &ek_mmc_data);
 	/* I2C */
-	at91_add_device_i2c();
+	at91_add_device_i2c(NULL, 0);
 }
 
 MACHINE_START(AT91SAM9260EK, "Atmel AT91SAM9260-EK")

arch/arm/mach-at91/board-sam9261ek.c

@@ -406,7 +406,7 @@ static void __init ek_board_init(void)
 	/* USB Device */
 	at91_add_device_udc(&ek_udc_data);
 	/* I2C */
-	at91_add_device_i2c();
+	at91_add_device_i2c(NULL, 0);
 	/* NAND */
 	at91_add_device_nand(&ek_nand_data);
 	/* DM9000 ethernet */

arch/arm/mach-at91/board-sam9263ek.c

@@ -291,7 +291,7 @@ static void __init ek_board_init(void)
 	/* NAND */
 	at91_add_device_nand(&ek_nand_data);
 	/* I2C */
-	at91_add_device_i2c();
+	at91_add_device_i2c(NULL, 0);
 	/* LCD Controller */
 	at91_add_device_lcdc(&ek_lcdc_data);
 	/* AC97 */

arch/arm/mach-at91/board-sam9rlek.c

@@ -181,7 +181,7 @@ static void __init ek_board_init(void)
 	/* Serial */
 	at91_add_device_serial();
 	/* I2C */
-	at91_add_device_i2c();
+	at91_add_device_i2c(NULL, 0);
 	/* NAND */
 	at91_add_device_nand(&ek_nand_data);
 	/* SPI */

include/asm-arm/arch-at91/board.h

@@ -33,6 +33,7 @@
 
 #include <linux/mtd/partitions.h>
 #include <linux/device.h>
+#include <linux/i2c.h>
 #include <linux/spi/spi.h>
 
  /* USB Device */
@@ -94,7 +95,7 @@ struct at91_nand_data {
 extern void __init at91_add_device_nand(struct at91_nand_data *data);
 
  /* I2C*/
-extern void __init at91_add_device_i2c(void);
+extern void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices);
 
  /* SPI */
 extern void __init at91_add_device_spi(struct spi_board_info *devices, int nr_devices);