diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/i2c/busses/i2c-pxa-pci.c | 5 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-tegra.c | 60 |
2 files changed, 49 insertions, 16 deletions
diff --git a/drivers/i2c/busses/i2c-pxa-pci.c b/drivers/i2c/busses/i2c-pxa-pci.c index 6659d269b841..b73da6cd6f91 100644 --- a/drivers/i2c/busses/i2c-pxa-pci.c +++ b/drivers/i2c/busses/i2c-pxa-pci.c @@ -109,12 +109,15 @@ static int __devinit ce4100_i2c_probe(struct pci_dev *dev, 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 2440b7411978..3c94c4a81a55 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -270,14 +270,30 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev) /* 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); - - buf += words_to_transfer * BYTES_PER_FIFO_WORD; - buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD; - tx_fifo_avail -= 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; + + /* + * 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 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev) 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 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id) 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 int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], 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 @@ static int tegra_i2c_resume(struct platform_device *pdev) } #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 @@ static struct platform_driver tegra_i2c_driver = { .driver = { .name = "tegra-i2c", .owner = THIS_MODULE, + .of_match_table = tegra_i2c_of_match, }, }; |