b3dc9566a4
As usual these patches were extracted from: https://github.com/raspberrypi/linux/commits/rpi-4.4.y Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> SVN-Revision: 48765
108 lines
3.4 KiB
Diff
108 lines
3.4 KiB
Diff
From dcca9b8b2f79033b8d0bbaacacc2726c74fc094e Mon Sep 17 00:00:00 2001
|
|
From: Devon Fyson <devonfyson@gmail.com>
|
|
Date: Wed, 30 Dec 2015 16:40:47 -0500
|
|
Subject: [PATCH 122/156] Extend clock timeout, fix modprobe baudrate
|
|
parameter.
|
|
|
|
Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.\n- Increase priority of baudrate parameter passed to modprobe (in /etc/modprobe.d/*.conf or command line). Currently custom baudrates don't work because they are overridden by clock-frequency in the platform_device passed to the function.
|
|
---
|
|
drivers/i2c/busses/i2c-bcm2708.c | 45 ++++++++++++++++++++++++++--------------
|
|
1 file changed, 29 insertions(+), 16 deletions(-)
|
|
|
|
--- a/drivers/i2c/busses/i2c-bcm2708.c
|
|
+++ b/drivers/i2c/busses/i2c-bcm2708.c
|
|
@@ -71,7 +71,8 @@
|
|
|
|
#define DRV_NAME "bcm2708_i2c"
|
|
|
|
-static unsigned int baudrate = CONFIG_I2C_BCM2708_BAUDRATE;
|
|
+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");
|
|
|
|
@@ -87,6 +88,7 @@ struct bcm2708_i2c {
|
|
int irq;
|
|
struct clk *clk;
|
|
u32 cdiv;
|
|
+ u32 clk_tout;
|
|
|
|
struct completion done;
|
|
|
|
@@ -126,7 +128,7 @@ static inline void bcm2708_bsc_fifo_fill
|
|
|
|
static inline int bcm2708_bsc_setup(struct bcm2708_i2c *bi)
|
|
{
|
|
- u32 cdiv, s;
|
|
+ u32 cdiv, s, clk_tout;
|
|
u32 c = BSC_C_I2CEN | BSC_C_INTD | BSC_C_ST | BSC_C_CLEAR_1;
|
|
int wait_loops = I2C_WAIT_LOOP_COUNT;
|
|
|
|
@@ -134,12 +136,14 @@ static inline int bcm2708_bsc_setup(stru
|
|
* Use the value that we cached in the probe.
|
|
*/
|
|
cdiv = bi->cdiv;
|
|
+ clk_tout = bi->clk_tout;
|
|
|
|
if (bi->msg->flags & I2C_M_RD)
|
|
c |= BSC_C_INTR | BSC_C_READ;
|
|
else
|
|
c |= BSC_C_INTT;
|
|
|
|
+ bcm2708_wr(bi, BSC_CLKT, clk_tout);
|
|
bcm2708_wr(bi, BSC_DIV, cdiv);
|
|
bcm2708_wr(bi, BSC_A, bi->msg->addr);
|
|
bcm2708_wr(bi, BSC_DLEN, bi->msg->len);
|
|
@@ -312,21 +316,24 @@ static int bcm2708_i2c_probe(struct plat
|
|
struct bcm2708_i2c *bi;
|
|
struct i2c_adapter *adap;
|
|
unsigned long bus_hz;
|
|
- u32 cdiv;
|
|
-
|
|
- 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;
|
|
+ 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");
|
|
}
|
|
- 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");
|
|
}
|
|
|
|
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
@@ -417,7 +424,13 @@ static int bcm2708_i2c_probe(struct plat
|
|
cdiv = 0xffff;
|
|
baudrate = bus_hz / cdiv;
|
|
}
|
|
+
|
|
+ clk_tout = 35/1000*baudrate; //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);
|