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From 76de914223ec09274a7857e0d8cd7b739205dc3c Mon Sep 17 00:00:00 2001
From: Gregory CLEMENT <gregory.clement@free-electrons.com>
Date: Fri, 21 Jun 2013 15:32:06 +0200
Subject: [PATCH 035/203] 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 <gregory.clement@free-electrons.com>
Signed-off-by: Zbigniew Bodek <zbb@semihalf.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
---
Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt | 6 +++++-
drivers/i2c/busses/i2c-mv64xxx.c | 6 +++++-
2 files changed, 10 insertions(+), 2 deletions(-)
--- 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:
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -580,7 +580,11 @@ mv64xxx_of_config(struct mv64xxx_i2c_dat
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;
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