blob: f305b88a984e766c0f656ebf52caca1aa966272d [file] [log] [blame]
From 6b52290ae18ec168dd341a3d40291ad8630818c0 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: 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>
(cherry picked from commit 4c730a06c19bb83d2fa4308ee4cbb23abc84c9ca)
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
---
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 f46d928aa73d..a1ee681942cc 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 ed854573b427..b1f42bf40963 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;
--
1.8.5.rc3