target/linux/mvebu/patches-3.10/0035-i2c-mv64xxx-Set-bus-frequency-to-100kHz-if-clock-fre.patch

   1 From 76de914223ec09274a7857e0d8cd7b739205dc3c Mon Sep 17 00:00:00 2001
   2 From: Gregory CLEMENT <gregory.clement@free-electrons.com>
   3 Date: Fri, 21 Jun 2013 15:32:06 +0200
   4 Subject: [PATCH 035/203] i2c: mv64xxx: Set bus frequency to 100kHz if
   5  clock-frequency is not provided
   6
   7 This commit adds checking whether clock-frequency property acquisition
   8 has succeeded. If not, the frequency is set to 100kHz by default.
   9
  10 The Device Tree binding documentation is updated accordingly.
  11
  12 Based on the intials patches from Zbigniew Bodek
  13
  14 Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
  15 Signed-off-by: Zbigniew Bodek <zbb@semihalf.com>
  16 Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
  17 ---
  18  Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt | 6 +++++-
  19  drivers/i2c/busses/i2c-mv64xxx.c                      | 6 +++++-
  20  2 files changed, 10 insertions(+), 2 deletions(-)
  21
  22 --- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
  23 +++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
  24 @@ -6,7 +6,11 @@ Required properties :
  25   - reg             : Offset and length of the register set for the device
  26   - compatible      : Should be "marvell,mv64xxx-i2c"
  27   - interrupts      : The interrupt number
  28 - - clock-frequency : Desired I2C bus clock frequency in Hz.
  29 +
  30 +Optional properties :
  31 +
  32 + - clock-frequency : Desired I2C bus clock frequency in Hz. If not set the
  33 +default frequency is 100kHz
  34
  35  Examples:
  36
  37 --- a/drivers/i2c/busses/i2c-mv64xxx.c
  38 +++ b/drivers/i2c/busses/i2c-mv64xxx.c
  39 @@ -580,7 +580,11 @@ mv64xxx_of_config(struct mv64xxx_i2c_dat
  40                 goto out;
  41         }
  42         tclk = clk_get_rate(drv_data->clk);
  43 -       of_property_read_u32(np, "clock-frequency", &bus_freq);
  44 +
  45 +       rc = of_property_read_u32(np, "clock-frequency", &bus_freq);
  46 +       if (rc)
  47 +               bus_freq = 100000; /* 100kHz by default */
  48 +
  49         if (!mv64xxx_find_baud_factors(bus_freq, tclk,
  50                                        &drv_data->freq_n, &drv_data->freq_m)) {
  51                 rc = -EINVAL;