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 <[email protected]>
---
drivers/i2c/busses/i2c-designware-platdrv.c | 31 ++++++++++++++++++++------
1 files changed, 24 insertions(+), 7 deletions(-)
Change from V4:
-Change else condition and add some comments to clarify new approach.
Change from V3:
-Use uppercase of FIFO instead of lowercase.
-Correct else condition when IP core return 0 of FIFO.
Change from V2:
-Add a helper function to set FIFO size.
Change from V1:
-Revert the default 32 for FIFO, read parameter from IP core
and pick the smaller one of the two.
-Correct the title to describe new approach.
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 0b42a12..682adc3 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);
@@ -246,13 +269,7 @@ 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;
--
1.7.1
On 12/14/2016 11:23 AM, Tin Huynh wrote:
> 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 <[email protected]>
>
> ---
> drivers/i2c/busses/i2c-designware-platdrv.c | 31 ++++++++++++++++++++------
> 1 files changed, 24 insertions(+), 7 deletions(-)
Acked-by: Jarkko Nikula <[email protected]>
On Wed, Dec 14, 2016 at 04:23:58PM +0700, Tin Huynh wrote:
> 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 <[email protected]>
Reviewed-by: Mika Westerberg <[email protected]>
On Wed, 2016-12-14 at 16:23 +0700, Tin Huynh wrote:
> 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 <[email protected]>
>
Reviewed-by: Andy Shevchenko <[email protected]>
> ---
> drivers/i2c/busses/i2c-designware-platdrv.c | 31
> ++++++++++++++++++++------
> 1 files changed, 24 insertions(+), 7 deletions(-)
>
> Change from V4:
> -Change else condition and add some comments to clarify new approach.
>
> Change from V3:
> -Use uppercase of FIFO instead of lowercase.
> -Correct else condition when IP core return 0 of FIFO.
>
> Change from V2:
> -Add a helper function to set FIFO size.
>
> Change from V1:
> -Revert the default 32 for FIFO, read parameter from IP core
> and pick the smaller one of the two.
> -Correct the title to describe new approach.
>
> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c
> b/drivers/i2c/busses/i2c-designware-platdrv.c
> index 0b42a12..682adc3 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);
> @@ -246,13 +269,7 @@ 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;
--
Andy Shevchenko <[email protected]>
Intel Finland Oy
On Wed, Dec 14, 2016 at 04:23:58PM +0700, Tin Huynh wrote:
> 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 <[email protected]>
>
Applied to for-current, thanks!