diff options
| author | Tin Huynh <tnhuynh@apm.com> | 2016-12-14 16:23:58 +0700 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2016-12-17 19:38:03 +0100 |
| commit | 8e598769c55dd6c442a1c6cbd21e7abda2a52215 (patch) | |
| tree | 4699efee8294941eef1aea4b592fb74478fb3db9 /drivers/i2c | |
| parent | 1635c5d04ea9343f0e3c74709c29995a23801ecd (diff) | |
| download | linux-8e598769c55dd6c442a1c6cbd21e7abda2a52215.tar.gz | |
i2c: designware: fix wrong Tx/Rx FIFO for ACPI
ACPI always sets Tx/Rx FIFO to 32. This configuration will cause problem if the IP core supports a FIFO size of less than 32. The driver should read the FIFO size from the IP and select the smaller one of the two. Signed-off-by: Tin Huynh <tnhuynh@apm.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-platdrv.c | 31 |
1 files changed, 24 insertions, 7 deletions
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 08153ea4d848..6ce431323125 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -150,6 +150,29 @@ static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare) return 0; } +static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id) +{ + u32 param, tx_fifo_depth, rx_fifo_depth; + + /* + * Try to detect the FIFO depth if not set by interface driver, + * the depth could be from 2 to 256 from HW spec. + */ + param = i2c_dw_read_comp_param(dev); + tx_fifo_depth = ((param >> 16) & 0xff) + 1; + rx_fifo_depth = ((param >> 8) & 0xff) + 1; + if (!dev->tx_fifo_depth) { + dev->tx_fifo_depth = tx_fifo_depth; + dev->rx_fifo_depth = rx_fifo_depth; + dev->adapter.nr = id; + } else if (tx_fifo_depth >= 2) { + dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth, + tx_fifo_depth); + dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth, + rx_fifo_depth); + } +} + static int dw_i2c_plat_probe(struct platform_device *pdev) { struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev); @@ -245,13 +268,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) 1000000); } - if (!dev->tx_fifo_depth) { - u32 param1 = i2c_dw_read_comp_param(dev); - - dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; - dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; - dev->adapter.nr = pdev->id; - } + dw_i2c_set_fifo_size(dev, pdev->id); adap = &dev->adapter; adap->owner = THIS_MODULE; |