i2c: at91: add new driver

This driver has the following properties compared to the old driver:
1. Support for multiple interfaces.
2. Interrupt driven I/O as opposed to polling/busy waiting.
3. Support for _one_ repeated start (Sr) condition, which is enough
   for most real-world applications including all SMBus transfer types.
   (The hardware does not support issuing arbitrary Sr conditions on the
    bus.)

testing: SoC: at91sam9g45
	 - BQ20Z80 battery SMBus client.
	 - on a 2.6.38 kernel with several i2c clients (temp-sensor,
	   audio-codec, touchscreen-controller, w1-bridge, io-expanders)

Signed-off-by: Nikolaus Voss <n.voss@weinmann.de>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Tested-by: Hubert Feurstein <h.feurstein@gmail.com>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Reviewed-by: Nicolas Ferre <nicolas.ferre@atmel.com>

[wsa: squashed with the following patches from Ludovic to have some flaws
fixed:
        i2c: at91: use managed resources
        i2c: at91: add warning about transmission issues for some devices
        i2c: at91: use an id table for SoC dependent parameters
]

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

1 files changed, 7 insertions, 1 deletions

diff --git a/arch/arm/mach-at91/at91sam9260_devices.c b/arch/arm/mach-at91/at91sam9260_devices.c
index bce572a530ef..95fc23aab432 100644
--- a/arch/arm/mach-at91/at91sam9260_devices.c
+++ b/arch/arm/mach-at91/at91sam9260_devices.c
@@ -503,7 +503,6 @@ static struct resource twi_resources[] = {
 };
 
 static struct platform_device at91sam9260_twi_device = {
-	.name		= "at91_i2c",
 	.id		= -1,
 	.resource	= twi_resources,
 	.num_resources	= ARRAY_SIZE(twi_resources),
@@ -511,6 +510,13 @@ static struct platform_device at91sam9260_twi_device = {
 
 void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices)
 {
+	/* IP version is not the same on 9260 and g20 */
+	if (cpu_is_at91sam9g20()) {
+		at91sam9260_twi_device.name = "i2c-at91sam9g20";
+	} else {
+		at91sam9260_twi_device.name = "i2c-at91sam9260";
+	}
+
 	/* pins used for TWI interface */
 	at91_set_A_periph(AT91_PIN_PA23, 0);		/* TWD */
 	at91_set_multi_drive(AT91_PIN_PA23, 1);