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i2c: designware: fix wrong Tx/Rx FIFO for ACPI

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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>
This commit is contained in:
Tin Huynh 2016-12-14 16:23:58 +07:00 committed by Wolfram Sang
parent 1635c5d04e
commit 8e598769c5
1 changed files with 24 additions and 7 deletions
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31
drivers/i2c/busses/i2c-designware-platdrv.c
View file

@ -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;