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Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0121-Extend-clock-timeout-fix-modprobe-baudrate-parameter.patch')
-rw-r--r--target/linux/brcm2708/patches-4.4/0121-Extend-clock-timeout-fix-modprobe-baudrate-parameter.patch108
1 files changed, 108 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0121-Extend-clock-timeout-fix-modprobe-baudrate-parameter.patch b/target/linux/brcm2708/patches-4.4/0121-Extend-clock-timeout-fix-modprobe-baudrate-parameter.patch
new file mode 100644
index 0000000000..18d02f2587
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.4/0121-Extend-clock-timeout-fix-modprobe-baudrate-parameter.patch
@@ -0,0 +1,108 @@
+From 127a32cdd6005a42f6b5b63de9d7db573d9de184 Mon Sep 17 00:00:00 2001
+From: Devon Fyson <devonfyson@gmail.com>
+Date: Wed, 30 Dec 2015 16:40:47 -0500
+Subject: [PATCH 121/232] 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);