| Message ID | 1481623414-19220-1-git-send-email-tnhuynh@apm.com |
|---|---|
| State | Superseded |
| Headers | show |
On Tue, 2016-12-13 at 17:03 +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 <tnhuynh@apm.com> > One comment below, after addressing it Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > --- > drivers/i2c/busses/i2c-designware-platdrv.c | 27 > ++++++++++++++++++++------- > 1 files changed, 20 insertions(+), 7 deletions(-) > > Change from V3: > -Use uppercase of FIFO instead of lowercase. > -Fix the problem 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..24032d6 100644 > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > @@ -150,6 +150,25 @@ 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 > 1) { This makes sense now, though I would add a comment here and use >= 2 to reflect datasheet. /* * Choose minimum values between HW and interface * driver provided. */ > + 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 +265,7 @@ 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;
On 12/13/2016 01:25 PM, Andy Shevchenko wrote: > On Tue, 2016-12-13 at 17:03 +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 <tnhuynh@apm.com> >> > > One comment below, after addressing it > > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Feel free to add my Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Dec 13, 2016 at 6:25 PM, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > On Tue, 2016-12-13 at 17:03 +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 <tnhuynh@apm.com> >> > > One comment below, after addressing it > > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > >> --- >> drivers/i2c/busses/i2c-designware-platdrv.c | 27 >> ++++++++++++++++++++------- >> 1 files changed, 20 insertions(+), 7 deletions(-) >> >> Change from V3: >> -Use uppercase of FIFO instead of lowercase. >> -Fix the problem 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..24032d6 100644 >> --- a/drivers/i2c/busses/i2c-designware-platdrv.c >> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c >> @@ -150,6 +150,25 @@ 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. > */ > I will add your comment to the driver. >> + 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 > 1) { > > This makes sense now, though I would add a comment here and use >= 2 to > reflect datasheet. > > /* > * Choose minimum values between HW and interface > * driver provided. > */ > I will implement as your comment. However , because adding 1 to the value , can i use > 2 or >=3 ? >> + 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 +265,7 @@ 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 <andriy.shevchenko@linux.intel.com> > Intel Finland Oy Thank you and regards, Tin -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 12/14/2016 05:20 AM, Tin Huynh wrote: > On Tue, Dec 13, 2016 at 6:25 PM, Andy Shevchenko >>> + 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 > 1) { >> >> This makes sense now, though I would add a comment here and use >= 2 to >> reflect datasheet. >> >> /* >> * Choose minimum values between HW and interface >> * driver provided. >> */ >> > I will implement as your comment. However , because adding 1 to the > value , can i use > 2 or >=3 ? either > 1 or >= 2 since register value 0x01 from HW means FIFO depth 2 and register value 0x00 is reserved.
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 0b42a12..24032d6 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -150,6 +150,25 @@ 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; + + 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 > 1) { + 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 +265,7 @@ 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;
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> --- drivers/i2c/busses/i2c-designware-platdrv.c | 27 ++++++++++++++++++++------- 1 files changed, 20 insertions(+), 7 deletions(-) Change from V3: -Use uppercase of FIFO instead of lowercase. -Fix the problem 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.