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>

12 files changed, 29 insertions, 15 deletions

diff --git a/arch/arm/mach-at91/at91rm9200.c b/arch/arm/mach-at91/at91rm9200.c
index f2112f9c1800..b4f0565aff63 100644
--- a/arch/arm/mach-at91/at91rm9200.c
+++ b/arch/arm/mach-at91/at91rm9200.c
@@ -187,7 +187,7 @@ static struct clk_lookup periph_clocks_lookups[] = {
         CLKDEV_CON_DEV_ID("pclk", "ssc.0", &ssc0_clk),
         CLKDEV_CON_DEV_ID("pclk", "ssc.1", &ssc1_clk),
         CLKDEV_CON_DEV_ID("pclk", "ssc.2", &ssc2_clk),
-        CLKDEV_CON_DEV_ID(NULL, "at91_i2c", &twi_clk),
+        CLKDEV_CON_DEV_ID(NULL, "i2c-at91rm9200", &twi_clk),
         /* fake hclk clock */
         CLKDEV_CON_DEV_ID("hclk", "at91_ohci", &ohci_clk),
         CLKDEV_CON_ID("pioA", &pioA_clk),
diff --git a/arch/arm/mach-at91/at91rm9200_devices.c b/arch/arm/mach-at91/at91rm9200_devices.c
index 01fb7325fecc..0b972f2e57eb 100644
--- a/arch/arm/mach-at91/at91rm9200_devices.c
+++ b/arch/arm/mach-at91/at91rm9200_devices.c
@@ -495,7 +495,7 @@ static struct resource twi_resources[] = {
 };
 
 static struct platform_device at91rm9200_twi_device = {
-        .name           = "at91_i2c",
+        .name           = "i2c-at91rm9200",
         .id             = -1,
         .resource       = twi_resources,
         .num_resources  = ARRAY_SIZE(twi_resources),
diff --git a/arch/arm/mach-at91/at91sam9260.c b/arch/arm/mach-at91/at91sam9260.c
index 57c79eed5fd0..5bd19a442365 100644
--- a/arch/arm/mach-at91/at91sam9260.c
+++ b/arch/arm/mach-at91/at91sam9260.c
@@ -211,7 +211,8 @@ static struct clk_lookup periph_clocks_lookups[] = {
         CLKDEV_CON_DEV_ID("t1_clk", "atmel_tcb.1", &tc4_clk),
         CLKDEV_CON_DEV_ID("t2_clk", "atmel_tcb.1", &tc5_clk),
         CLKDEV_CON_DEV_ID("pclk", "ssc.0", &ssc_clk),
-        CLKDEV_CON_DEV_ID(NULL, "at91_i2c", &twi_clk),
+        CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9260", &twi_clk),
+        CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9g20", &twi_clk),
         /* more usart lookup table for DT entries */
         CLKDEV_CON_DEV_ID("usart", "fffff200.serial", &mck),
         CLKDEV_CON_DEV_ID("usart", "fffb0000.serial", &usart0_clk),
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);
diff --git a/arch/arm/mach-at91/at91sam9261.c b/arch/arm/mach-at91/at91sam9261.c
index 71ca1e06a16f..8d999eb1a137 100644
--- a/arch/arm/mach-at91/at91sam9261.c
+++ b/arch/arm/mach-at91/at91sam9261.c
@@ -178,7 +178,8 @@ static struct clk_lookup periph_clocks_lookups[] = {
         CLKDEV_CON_DEV_ID("pclk", "ssc.1", &ssc1_clk),
         CLKDEV_CON_DEV_ID("pclk", "ssc.2", &ssc2_clk),
         CLKDEV_CON_DEV_ID("hclk", "at91_ohci", &hck0),
-        CLKDEV_CON_DEV_ID(NULL, "at91_i2c", &twi_clk),
+        CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9261", &twi_clk),
+        CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9g10", &twi_clk),
         CLKDEV_CON_ID("pioA", &pioA_clk),
         CLKDEV_CON_ID("pioB", &pioB_clk),
         CLKDEV_CON_ID("pioC", &pioC_clk),
diff --git a/arch/arm/mach-at91/at91sam9261_devices.c b/arch/arm/mach-at91/at91sam9261_devices.c
index bc2590d712d0..29188ef7422b 100644
--- a/arch/arm/mach-at91/at91sam9261_devices.c
+++ b/arch/arm/mach-at91/at91sam9261_devices.c
@@ -317,7 +317,6 @@ static struct resource twi_resources[] = {
 };
 
 static struct platform_device at91sam9261_twi_device = {
-        .name           = "at91_i2c",
         .id             = -1,
         .resource       = twi_resources,
         .num_resources  = ARRAY_SIZE(twi_resources),
@@ -325,6 +324,13 @@ static struct platform_device at91sam9261_twi_device = {
 
 void __init at91_add_device_i2c(struct i2c_board_info *devices, int nr_devices)
 {
+        /* IP version is not the same on 9261 and g10 */
+        if (cpu_is_at91sam9g10()) {
+                at91sam9261_twi_device.name = "i2c-at91sam9g10";
+        } else {
+                at91sam9261_twi_device.name = "i2c-at91sam9261";
+        }
+
         /* pins used for TWI interface */
         at91_set_A_periph(AT91_PIN_PA7, 0);             /* TWD */
         at91_set_multi_drive(AT91_PIN_PA7, 1);
diff --git a/arch/arm/mach-at91/at91sam9263.c b/arch/arm/mach-at91/at91sam9263.c
index 2a08305b6571..e6b595658e75 100644
--- a/arch/arm/mach-at91/at91sam9263.c
+++ b/arch/arm/mach-at91/at91sam9263.c
@@ -193,7 +193,7 @@ static struct clk_lookup periph_clocks_lookups[] = {
         CLKDEV_CON_DEV_ID("spi_clk", "atmel_spi.0", &spi0_clk),
         CLKDEV_CON_DEV_ID("spi_clk", "atmel_spi.1", &spi1_clk),
         CLKDEV_CON_DEV_ID("t0_clk", "atmel_tcb.0", &tcb_clk),
-        CLKDEV_CON_DEV_ID(NULL, "at91_i2c", &twi_clk),
+        CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9260", &twi_clk),
         /* fake hclk clock */
         CLKDEV_CON_DEV_ID("hclk", "at91_ohci", &ohci_clk),
         CLKDEV_CON_ID("pioA", &pioA_clk),
diff --git a/arch/arm/mach-at91/at91sam9263_devices.c b/arch/arm/mach-at91/at91sam9263_devices.c
index 9b6ca734f1a9..3f5288ea64b9 100644
--- a/arch/arm/mach-at91/at91sam9263_devices.c
+++ b/arch/arm/mach-at91/at91sam9263_devices.c
@@ -574,7 +574,7 @@ static struct resource twi_resources[] = {
 };
 
 static struct platform_device at91sam9263_twi_device = {
-        .name           = "at91_i2c",
+        .name           = "i2c-at91sam9260",
         .id             = -1,
         .resource       = twi_resources,
         .num_resources  = ARRAY_SIZE(twi_resources),
diff --git a/arch/arm/mach-at91/at91sam9g45.c b/arch/arm/mach-at91/at91sam9g45.c
index ddf3d3707c54..858f032e5102 100644
--- a/arch/arm/mach-at91/at91sam9g45.c
+++ b/arch/arm/mach-at91/at91sam9g45.c
@@ -237,8 +237,8 @@ static struct clk_lookup periph_clocks_lookups[] = {
         CLKDEV_CON_DEV_ID("spi_clk", "atmel_spi.1", &spi1_clk),
         CLKDEV_CON_DEV_ID("t0_clk", "atmel_tcb.0", &tcb0_clk),
         CLKDEV_CON_DEV_ID("t0_clk", "atmel_tcb.1", &tcb0_clk),
-        CLKDEV_CON_DEV_ID(NULL, "at91_i2c.0", &twi0_clk),
-        CLKDEV_CON_DEV_ID(NULL, "at91_i2c.1", &twi1_clk),
+        CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9g10.0", &twi0_clk),
+        CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9g10.1", &twi1_clk),
         CLKDEV_CON_DEV_ID("pclk", "ssc.0", &ssc0_clk),
         CLKDEV_CON_DEV_ID("pclk", "ssc.1", &ssc1_clk),
         CLKDEV_CON_DEV_ID(NULL, "atmel-trng", &trng_clk),
diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
index 1b47319ca00b..ac1b0f8c3b31 100644
--- a/arch/arm/mach-at91/at91sam9g45_devices.c
+++ b/arch/arm/mach-at91/at91sam9g45_devices.c
@@ -653,7 +653,7 @@ static struct resource twi0_resources[] = {
 };
 
 static struct platform_device at91sam9g45_twi0_device = {
-        .name           = "at91_i2c",
+        .name           = "i2c-at91sam9g10",
         .id             = 0,
         .resource       = twi0_resources,
         .num_resources  = ARRAY_SIZE(twi0_resources),
@@ -673,7 +673,7 @@ static struct resource twi1_resources[] = {
 };
 
 static struct platform_device at91sam9g45_twi1_device = {
-        .name           = "at91_i2c",
+        .name           = "i2c-at91sam9g10",
         .id             = 1,
         .resource       = twi1_resources,
         .num_resources  = ARRAY_SIZE(twi1_resources),
diff --git a/arch/arm/mach-at91/at91sam9rl.c b/arch/arm/mach-at91/at91sam9rl.c
index bf79c1fd5939..72e908412222 100644
--- a/arch/arm/mach-at91/at91sam9rl.c
+++ b/arch/arm/mach-at91/at91sam9rl.c
@@ -186,8 +186,8 @@ static struct clk_lookup periph_clocks_lookups[] = {
         CLKDEV_CON_DEV_ID("t2_clk", "atmel_tcb.0", &tc2_clk),
         CLKDEV_CON_DEV_ID("pclk", "ssc.0", &ssc0_clk),
         CLKDEV_CON_DEV_ID("pclk", "ssc.1", &ssc1_clk),
-        CLKDEV_CON_DEV_ID(NULL, "at91_i2c.0", &twi0_clk),
-        CLKDEV_CON_DEV_ID(NULL, "at91_i2c.1", &twi1_clk),
+        CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9g20.0", &twi0_clk),
+        CLKDEV_CON_DEV_ID(NULL, "i2c-at91sam9g20.1", &twi1_clk),
         CLKDEV_CON_ID("pioA", &pioA_clk),
         CLKDEV_CON_ID("pioB", &pioB_clk),
         CLKDEV_CON_ID("pioC", &pioC_clk),
diff --git a/arch/arm/mach-at91/at91sam9rl_devices.c b/arch/arm/mach-at91/at91sam9rl_devices.c
index b3d365dadef5..0794954953e5 100644
--- a/arch/arm/mach-at91/at91sam9rl_devices.c
+++ b/arch/arm/mach-at91/at91sam9rl_devices.c
@@ -346,7 +346,7 @@ static struct resource twi_resources[] = {
 };
 
 static struct platform_device at91sam9rl_twi_device = {
-        .name           = "at91_i2c",
+        .name           = "i2c-at91sam9g20",
         .id             = -1,
         .resource       = twi_resources,
         .num_resources  = ARRAY_SIZE(twi_resources),