openwrt_archive/target/linux/brcm2708/patches-4.4/0142-FIXUP-i2c_bcm2708-Don-t-change-module-baudrate-param.patch
John Crispin 77c76183d6 brcm2708: update linux 4.4 patches to latest version
As usual these patches were extracted from the raspberry pi repo:
https://github.com/raspberrypi/linux/tree/rpi-4.4.y

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

SVN-Revision: 48966
2016-03-08 18:11:49 +00:00

100 lines
2.8 KiB
Diff

From 7519a79f61a67792e238a118db58600fb5f60ec8 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Tue, 19 Jan 2016 16:28:05 +0000
Subject: [PATCH 142/170] FIXUP i2c_bcm2708: Don't change module baudrate
parameter
Overwriting the baudrate module parameter creates an apparent
forced baudrate for i2c busses after the first. Not only does this
override the baudrate from DT it also prevents the bus ID from
being initialised.
Also fix whitespace errors.
---
drivers/i2c/busses/i2c-bcm2708.c | 48 +++++++++++++++++++++-------------------
1 file changed, 25 insertions(+), 23 deletions(-)
--- a/drivers/i2c/busses/i2c-bcm2708.c
+++ b/drivers/i2c/busses/i2c-bcm2708.c
@@ -71,7 +71,6 @@
#define DRV_NAME "bcm2708_i2c"
-static unsigned int baudrate_default = CONFIG_I2C_BCM2708_BAUDRATE;
static unsigned int baudrate;
module_param(baudrate, uint, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
MODULE_PARM_DESC(baudrate, "The I2C baudrate");
@@ -317,25 +316,28 @@ static int bcm2708_i2c_probe(struct plat
struct i2c_adapter *adap;
unsigned long bus_hz;
u32 cdiv, clk_tout;
-
- if (!baudrate) {
- baudrate = baudrate_default;
- if (pdev->dev.of_node) {
- u32 bus_clk_rate;
- pdev->id = of_alias_get_id(pdev->dev.of_node, "i2c");
- if (pdev->id < 0) {
- dev_err(&pdev->dev, "alias is missing\n");
- return -EINVAL;
- }
- if (!of_property_read_u32(pdev->dev.of_node,
- "clock-frequency", &bus_clk_rate))
- baudrate = bus_clk_rate;
- else
- dev_warn(&pdev->dev,
- "Could not read clock-frequency property\n");
+ u32 baud;
+
+ baud = CONFIG_I2C_BCM2708_BAUDRATE;
+
+ if (pdev->dev.of_node) {
+ u32 bus_clk_rate;
+ pdev->id = of_alias_get_id(pdev->dev.of_node, "i2c");
+ if (pdev->id < 0) {
+ dev_err(&pdev->dev, "alias is missing\n");
+ return -EINVAL;
}
+ if (!of_property_read_u32(pdev->dev.of_node,
+ "clock-frequency", &bus_clk_rate))
+ baud = bus_clk_rate;
+ else
+ dev_warn(&pdev->dev,
+ "Could not read clock-frequency property\n");
}
+ if (baudrate)
+ baud = baudrate;
+
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!regs) {
dev_err(&pdev->dev, "could not get IO memory\n");
@@ -419,21 +421,21 @@ static int bcm2708_i2c_probe(struct plat
}
bus_hz = clk_get_rate(bi->clk);
- cdiv = bus_hz / baudrate;
+ cdiv = bus_hz / baud;
if (cdiv > 0xffff) {
cdiv = 0xffff;
- baudrate = bus_hz / cdiv;
+ baud = bus_hz / cdiv;
}
-
- clk_tout = 35/1000*baudrate; //35ms timeout as per SMBus specs.
- if (clk_tout > 0xffff)
+
+ clk_tout = 35/1000*baud; //35ms timeout as per SMBus specs.
+ if (clk_tout > 0xffff)
clk_tout = 0xffff;
bi->cdiv = cdiv;
bi->clk_tout = clk_tout;
dev_info(&pdev->dev, "BSC%d Controller at 0x%08lx (irq %d) (baudrate %d)\n",
- pdev->id, (unsigned long)regs->start, irq, baudrate);
+ pdev->id, (unsigned long)regs->start, irq, baud);
return 0;