Merge branch 'for-31-rc5/i2c-fixes' of git://git.fluff.org/bjdooks/linux
* 'for-31-rc5/i2c-fixes' of git://git.fluff.org/bjdooks/linux:
i2c-tegra: fix possible race condition after tx
i2c-tegra: add I2C_FUNC_SMBUS_EMUL
i2c-tegra: Add of_match_table
i2c-pxa2xx: return proper error code in ce4100_i2c_probe error paths
diff --git a/drivers/i2c/busses/i2c-pxa-pci.c b/drivers/i2c/busses/i2c-pxa-pci.c
index 6659d26..b73da6c 100644
--- a/drivers/i2c/busses/i2c-pxa-pci.c
+++ b/drivers/i2c/busses/i2c-pxa-pci.c
@@ -109,12 +109,15 @@
return -EINVAL;
}
sds = kzalloc(sizeof(*sds), GFP_KERNEL);
- if (!sds)
+ if (!sds) {
+ ret = -ENOMEM;
goto err_mem;
+ }
for (i = 0; i < ARRAY_SIZE(sds->pdev); i++) {
sds->pdev[i] = add_i2c_device(dev, i);
if (IS_ERR(sds->pdev[i])) {
+ ret = PTR_ERR(sds->pdev[i]);
while (--i >= 0)
platform_device_unregister(sds->pdev[i]);
goto err_dev_add;
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 2440b74..3c94c4a 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -270,14 +270,30 @@
/* Rounds down to not include partial word at the end of buf */
words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
- if (words_to_transfer > tx_fifo_avail)
- words_to_transfer = tx_fifo_avail;
- i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
+ /* It's very common to have < 4 bytes, so optimize that case. */
+ if (words_to_transfer) {
+ if (words_to_transfer > tx_fifo_avail)
+ words_to_transfer = tx_fifo_avail;
- buf += words_to_transfer * BYTES_PER_FIFO_WORD;
- buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
- tx_fifo_avail -= words_to_transfer;
+ /*
+ * Update state before writing to FIFO. If this casues us
+ * to finish writing all bytes (AKA buf_remaining goes to 0) we
+ * have a potential for an interrupt (PACKET_XFER_COMPLETE is
+ * not maskable). We need to make sure that the isr sees
+ * buf_remaining as 0 and doesn't call us back re-entrantly.
+ */
+ buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
+ tx_fifo_avail -= words_to_transfer;
+ i2c_dev->msg_buf_remaining = buf_remaining;
+ i2c_dev->msg_buf = buf +
+ words_to_transfer * BYTES_PER_FIFO_WORD;
+ barrier();
+
+ i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
+
+ buf += words_to_transfer * BYTES_PER_FIFO_WORD;
+ }
/*
* If there is a partial word at the end of buf, handle it manually to
@@ -287,14 +303,15 @@
if (tx_fifo_avail > 0 && buf_remaining > 0) {
BUG_ON(buf_remaining > 3);
memcpy(&val, buf, buf_remaining);
+
+ /* Again update before writing to FIFO to make sure isr sees. */
+ i2c_dev->msg_buf_remaining = 0;
+ i2c_dev->msg_buf = NULL;
+ barrier();
+
i2c_writel(i2c_dev, val, I2C_TX_FIFO);
- buf_remaining = 0;
- tx_fifo_avail--;
}
- BUG_ON(tx_fifo_avail > 0 && buf_remaining > 0);
- i2c_dev->msg_buf_remaining = buf_remaining;
- i2c_dev->msg_buf = buf;
return 0;
}
@@ -411,9 +428,10 @@
tegra_i2c_mask_irq(i2c_dev, I2C_INT_TX_FIFO_DATA_REQ);
}
- if ((status & I2C_INT_PACKET_XFER_COMPLETE) &&
- !i2c_dev->msg_buf_remaining)
+ if (status & I2C_INT_PACKET_XFER_COMPLETE) {
+ BUG_ON(i2c_dev->msg_buf_remaining);
complete(&i2c_dev->msg_complete);
+ }
i2c_writel(i2c_dev, status, I2C_INT_STATUS);
if (i2c_dev->is_dvc)
@@ -531,7 +549,7 @@
static u32 tegra_i2c_func(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C;
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static const struct i2c_algorithm tegra_i2c_algo = {
@@ -719,6 +737,17 @@
}
#endif
+#if defined(CONFIG_OF)
+/* Match table for of_platform binding */
+static const struct of_device_id tegra_i2c_of_match[] __devinitconst = {
+ { .compatible = "nvidia,tegra20-i2c", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);
+#else
+#define tegra_i2c_of_match NULL
+#endif
+
static struct platform_driver tegra_i2c_driver = {
.probe = tegra_i2c_probe,
.remove = tegra_i2c_remove,
@@ -729,6 +758,7 @@
.driver = {
.name = "tegra-i2c",
.owner = THIS_MODULE,
+ .of_match_table = tegra_i2c_of_match,
},
};