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authorImre Kaloz <kaloz@openwrt.org>2012-09-27 08:06:13 +0000
committerImre Kaloz <kaloz@openwrt.org>2012-09-27 08:06:13 +0000
commit9ace6ace8f7d8317a2bcf3704127842197aff437 (patch)
treeb4baa6c5c2089c8ee6739338c10c2df9377a7813 /target/linux
parent7dd6b04c28eb82fdc1af2d50cb35ce65baa6fa27 (diff)
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add i2c retries
Signed-off-by: Tim Harvey <tharvey@gateworks.com> SVN-Revision: 33565
Diffstat (limited to 'target/linux')
-rw-r--r--target/linux/cns3xxx/patches-3.3/440-i2c_retry.patch72
1 files changed, 72 insertions, 0 deletions
diff --git a/target/linux/cns3xxx/patches-3.3/440-i2c_retry.patch b/target/linux/cns3xxx/patches-3.3/440-i2c_retry.patch
new file mode 100644
index 0000000..707de82
--- /dev/null
+++ b/target/linux/cns3xxx/patches-3.3/440-i2c_retry.patch
@@ -0,0 +1,72 @@
+--- a/drivers/i2c/busses/i2c-cns3xxx.c
++++ b/drivers/i2c/busses/i2c-cns3xxx.c
+@@ -2,8 +2,9 @@
+ * Cavium CNS3xxx I2C Host Controller
+ *
+ * Copyright 2010 Cavium Network
+- * Copyright 2011 Gateworks Corporation
++ * Copyright 2012 Gateworks Corporation
+ * Chris Lang <clang@gateworks.com>
++ * Tim Harvey <tharvey@gateworks.com>
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, Version 2, as
+@@ -63,13 +64,15 @@
+ #define STATE_ERROR 2
+
+ struct cns3xxx_i2c {
+- void __iomem *base;
+- wait_queue_head_t wait;
+- struct i2c_adapter adap;
+- struct i2c_msg *msg;
+- int state; /* see STATE_ */
+- int rd_wr_len;
+- u8 *buf;
++ struct device *dev;
++ void __iomem *base; /* virtual */
++ wait_queue_head_t wait;
++ struct i2c_adapter adap;
++ struct i2c_msg *msg;
++ u8 state; /* see STATE_ */
++ u8 error; /* see TWI_STATUS register */
++ int rd_wr_len;
++ u8 *buf;
+ };
+
+ static u32 cns3xxx_i2c_func(struct i2c_adapter *adap)
+@@ -150,14 +153,18 @@ cns3xxx_i2c_xfer_msg(struct i2c_adapter
+
+ // Start the Transfer
+ i2c->state = 0; // Clear out the State
++ i2c->error = 0;
+ I2C_CONTROLLER_REG |= (1 << 6);
+
+ if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) ||
+ (i2c->state == STATE_DONE), TWI_TIMEOUT)) {
+ if (i2c->state == STATE_ERROR) {
+- return -EIO;
++ dev_dbg(i2c->dev, "controller error: 0x%2x", i2c->error);
++ return -EAGAIN; // try again
+ }
+ } else {
++ dev_err(i2c->dev, "controller timed out "
++ "waiting for start condition to finish\n");
+ return -ETIMEDOUT;
+ }
+ }
+@@ -238,6 +245,7 @@ static irqreturn_t cns3xxx_i2c_isr(int i
+
+ if (stat & I2C_BUS_ERROR_FLAG) {
+ i2c->state = STATE_ERROR;
++ i2c->error = (I2C_INTERRUPT_STATUS_REG & 0xff00)>>8;
+ } else {
+ if (i2c->msg->flags & I2C_M_RD) {
+ for (i = 0; i <= i2c->rd_wr_len; i++)
+@@ -280,6 +288,7 @@ static int __devinit cns3xxx_i2c_probe(s
+ goto request_mem_failed;
+ }
+
++ i2c->dev = &pdev->dev;
+ i2c->base = ioremap(res->start, res->end - res->start + 1);
+ if (!i2c->base) {
+ dev_err(&pdev->dev, "Unable to map registers\n");