From 4c730a06c19bb83d2fa4308ee4cbb23abc84c9ca Mon Sep 17 00:00:00 2001 From: Gregory CLEMENT Date: Fri, 21 Jun 2013 15:32:06 +0200 Subject: [PATCH] i2c: mv64xxx: Set bus frequency to 100kHz if clock-frequency is not provided This commit adds checking whether clock-frequency property acquisition has succeeded. If not, the frequency is set to 100kHz by default. The Device Tree binding documentation is updated accordingly. Based on the intials patches from Zbigniew Bodek Signed-off-by: Gregory CLEMENT Signed-off-by: Zbigniew Bodek Signed-off-by: Wolfram Sang --- Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt | 6 +++++- drivers/i2c/busses/i2c-mv64xxx.c | 6 +++++- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt index f46d928..a1ee681 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt @@ -6,7 +6,11 @@ Required properties : - reg : Offset and length of the register set for the device - compatible : Should be "marvell,mv64xxx-i2c" - interrupts : The interrupt number - - clock-frequency : Desired I2C bus clock frequency in Hz. + +Optional properties : + + - clock-frequency : Desired I2C bus clock frequency in Hz. If not set the +default frequency is 100kHz Examples: diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c index ed85457..b1f42bf 100644 --- a/drivers/i2c/busses/i2c-mv64xxx.c +++ b/drivers/i2c/busses/i2c-mv64xxx.c @@ -578,7 +578,11 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data, goto out; } tclk = clk_get_rate(drv_data->clk); - of_property_read_u32(np, "clock-frequency", &bus_freq); + + rc = of_property_read_u32(np, "clock-frequency", &bus_freq); + if (rc) + bus_freq = 100000; /* 100kHz by default */ + if (!mv64xxx_find_baud_factors(bus_freq, tclk, &drv_data->freq_n, &drv_data->freq_m)) { rc = -EINVAL; -- 2.7.4