diff options
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-at91.txt | 2 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-at91.c | 10 |
2 files changed, 10 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-at91.txt b/Documentation/devicetree/bindings/i2c/i2c-at91.txt index 4fade84bea1..388f0a275fb 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-at91.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-at91.txt @@ -12,6 +12,7 @@ Required properties : - clocks: phandles to input clocks. Optional properties: +- clock-frequency: Desired I2C bus frequency in Hz, otherwise defaults to 100000 - Child nodes conforming to i2c bus binding Examples : @@ -23,6 +24,7 @@ i2c0: i2c@fff84000 { #address-cells = <1>; #size-cells = <0>; clocks = <&twi0_clk>; + clock-frequency = <400000>; 24c512@50 { compatible = "24c512"; diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c index 56baf48fb99..e95f9ba9679 100644 --- a/drivers/i2c/busses/i2c-at91.c +++ b/drivers/i2c/busses/i2c-at91.c @@ -32,7 +32,7 @@ #include <linux/slab.h> #include <linux/platform_data/dma-atmel.h> -#define TWI_CLK_HZ 100000 /* max 400 Kbits/s */ +#define DEFAULT_TWI_CLK_HZ 100000 /* max 400 Kbits/s */ #define AT91_I2C_TIMEOUT msecs_to_jiffies(100) /* transfer timeout */ #define AT91_I2C_DMA_THRESHOLD 8 /* enable DMA if transfer size is bigger than this threshold */ @@ -711,6 +711,7 @@ static int at91_twi_probe(struct platform_device *pdev) struct resource *mem; int rc; u32 phy_addr; + u32 bus_clk_rate; dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); if (!dev) @@ -756,7 +757,12 @@ static int at91_twi_probe(struct platform_device *pdev) dev->use_dma = true; } - at91_calc_twi_clock(dev, TWI_CLK_HZ); + rc = of_property_read_u32(dev->dev->of_node, "clock-frequency", + &bus_clk_rate); + if (rc) + bus_clk_rate = DEFAULT_TWI_CLK_HZ; + + at91_calc_twi_clock(dev, bus_clk_rate); at91_init_twi_bus(dev); snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91"); |