Message ID | 1408544948-22339-1-git-send-email-romainba@abilis.com |
---|---|
State | Accepted |
Headers | show |
On Wed, 20 Aug 2014, Romain Baeriswyl wrote: > From: Romain Baeriswyl <Romain.Baeriswyl@abilis.com> > > Some legacy devices support ony I2C standard mode at 100kHz. > This patch allows to select the standard mode through the DTS > with the use of the existing clock-frequency parameter. > > When clock-frequency parameter is not set, the fast mode is selected. > Only when the parameter is set at 100000, the standard mode is selected. > > Signed-off-by: Romain Baeriswyl <romainba@abilis.com> > Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com> > --- > drivers/i2c/busses/i2c-designware-platdrv.c | 23 +++++++++++++++++++++-- > 1 files changed, 21 insertions(+), 2 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c > index 402ec39..b543fe1 100644 > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > @@ -122,6 +122,7 @@ static int dw_i2c_probe(struct platform_device *pdev) > struct i2c_adapter *adap; > struct resource *mem; > int irq, r; > + u32 clk_freq; > > irq = platform_get_irq(pdev, 0); > if (irq < 0) { > @@ -151,6 +152,9 @@ static int dw_i2c_probe(struct platform_device *pdev) > return PTR_ERR(dev->clk); > clk_prepare_enable(dev->clk); > > + /* fast mode by default because of legacy reasons */ > + clk_freq = 400000; > + > if (pdev->dev.of_node) { > u32 ht = 0; > u32 ic_clk = dev->get_clk_rate_khz(dev); > @@ -166,6 +170,17 @@ static int dw_i2c_probe(struct platform_device *pdev) > of_property_read_u32(pdev->dev.of_node, > "i2c-scl-falling-time-ns", > &dev->scl_falling_time); > + > + of_property_read_u32(pdev->dev.of_node, "clock-frequency", > + &clk_freq); > + > + /* Only standard mode at 100kHz and fast mode at 400kHz > + * are supported. > + */ > + if (clk_freq != 100000 && clk_freq != 400000) { > + dev_err(&pdev->dev, "Only 100kHz and 400kHz supported"); > + return -EINVAL; > + } Hi Romain, It is common to operate i2c at <100KHz on boards that have i2c issues. I am using this driver at 50KHz because I have a LCD module that just doesn't work at a full 100KHz. Please remove the check for these two frequency points. > } > > dev->functionality = > @@ -175,8 +190,12 @@ static int dw_i2c_probe(struct platform_device *pdev) > I2C_FUNC_SMBUS_BYTE_DATA | > I2C_FUNC_SMBUS_WORD_DATA | > I2C_FUNC_SMBUS_I2C_BLOCK; > - dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | > - DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; > + if (clk_freq == 100000) Please change to <= > + dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | > + DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD; > + else > + dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | > + DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; > > /* Try first if we can configure the device from ACPI */ > r = dw_i2c_acpi_configure(pdev); > -- > 1.7.1 > > -- 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 Wed, 20 Aug 2014, atull wrote: > > > On Wed, 20 Aug 2014, Romain Baeriswyl wrote: > > > From: Romain Baeriswyl <Romain.Baeriswyl@abilis.com> > > > > Some legacy devices support ony I2C standard mode at 100kHz. > > This patch allows to select the standard mode through the DTS > > with the use of the existing clock-frequency parameter. > > > > When clock-frequency parameter is not set, the fast mode is selected. > > Only when the parameter is set at 100000, the standard mode is selected. > > > > Signed-off-by: Romain Baeriswyl <romainba@abilis.com> > > Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com> > > --- > > drivers/i2c/busses/i2c-designware-platdrv.c | 23 +++++++++++++++++++++-- > > 1 files changed, 21 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c > > index 402ec39..b543fe1 100644 > > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > > @@ -122,6 +122,7 @@ static int dw_i2c_probe(struct platform_device *pdev) > > struct i2c_adapter *adap; > > struct resource *mem; > > int irq, r; > > + u32 clk_freq; > > > > irq = platform_get_irq(pdev, 0); > > if (irq < 0) { > > @@ -151,6 +152,9 @@ static int dw_i2c_probe(struct platform_device *pdev) > > return PTR_ERR(dev->clk); > > clk_prepare_enable(dev->clk); > > > > + /* fast mode by default because of legacy reasons */ > > + clk_freq = 400000; > > + > > if (pdev->dev.of_node) { > > u32 ht = 0; > > u32 ic_clk = dev->get_clk_rate_khz(dev); > > @@ -166,6 +170,17 @@ static int dw_i2c_probe(struct platform_device *pdev) > > of_property_read_u32(pdev->dev.of_node, > > "i2c-scl-falling-time-ns", > > &dev->scl_falling_time); > > + > > + of_property_read_u32(pdev->dev.of_node, "clock-frequency", > > + &clk_freq); > > + > > + /* Only standard mode at 100kHz and fast mode at 400kHz > > + * are supported. > > + */ > > + if (clk_freq != 100000 && clk_freq != 400000) { > > + dev_err(&pdev->dev, "Only 100kHz and 400kHz supported"); > > + return -EINVAL; > > + } > > Hi Romain, > > It is common to operate i2c at <100KHz on boards that have i2c > issues. I am using this driver at 50KHz because I have a LCD module > that just doesn't work at a full 100KHz. Please remove the check for > these two frequency points. > > > } > > > > dev->functionality = > > @@ -175,8 +190,12 @@ static int dw_i2c_probe(struct platform_device *pdev) > > I2C_FUNC_SMBUS_BYTE_DATA | > > I2C_FUNC_SMBUS_WORD_DATA | > > I2C_FUNC_SMBUS_I2C_BLOCK; > > - dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | > > - DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; > > + if (clk_freq == 100000) > > Please change to <= > Hi Romain, This looks fine to me, my "<= issues" are not important as this isn't really setting a frequency, but just setting a bit that controls speed. Acked-by: Alan Tull <atull@opensource.altera.com> > > + dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | > > + DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD; > > + else > > + dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | > > + DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; > > > > /* Try first if we can configure the device from ACPI */ > > r = dw_i2c_acpi_configure(pdev); > > -- > > 1.7.1 > > > > > -- 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 Wed, 20 Aug 2014, Romain Baeriswyl wrote: > From: Romain Baeriswyl <Romain.Baeriswyl@abilis.com> > > Some legacy devices support ony I2C standard mode at 100kHz. > This patch allows to select the standard mode through the DTS > with the use of the existing clock-frequency parameter. > > When clock-frequency parameter is not set, the fast mode is selected. > Only when the parameter is set at 100000, the standard mode is selected. > > Signed-off-by: Romain Baeriswyl <romainba@abilis.com> > Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com> > --- > drivers/i2c/busses/i2c-designware-platdrv.c | 23 +++++++++++++++++++++-- > 1 files changed, 21 insertions(+), 2 deletions(-) > Hi Wolfram, This patch is really useful for us. Is it going to be picked up? Alan -- 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 Wed, Aug 20, 2014 at 04:29:08PM +0200, Romain Baeriswyl wrote: > From: Romain Baeriswyl <Romain.Baeriswyl@abilis.com> > > Some legacy devices support ony I2C standard mode at 100kHz. > This patch allows to select the standard mode through the DTS > with the use of the existing clock-frequency parameter. > > When clock-frequency parameter is not set, the fast mode is selected. > Only when the parameter is set at 100000, the standard mode is selected. > > Signed-off-by: Romain Baeriswyl <romainba@abilis.com> > Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com> Applied to for-next, thanks to all involved!
On Sat, 20 Sep 2014, Wolfram Sang wrote: > On Wed, Aug 20, 2014 at 04:29:08PM +0200, Romain Baeriswyl wrote: > > From: Romain Baeriswyl <Romain.Baeriswyl@abilis.com> > > > > Some legacy devices support ony I2C standard mode at 100kHz. > > This patch allows to select the standard mode through the DTS > > with the use of the existing clock-frequency parameter. > > > > When clock-frequency parameter is not set, the fast mode is selected. > > Only when the parameter is set at 100000, the standard mode is selected. > > > > Signed-off-by: Romain Baeriswyl <romainba@abilis.com> > > Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com> > > Applied to for-next, thanks to all involved! > > I don't see this in git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git Is this in i2c/i2c/for-next? Alan -- 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
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 402ec39..b543fe1 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -122,6 +122,7 @@ static int dw_i2c_probe(struct platform_device *pdev) struct i2c_adapter *adap; struct resource *mem; int irq, r; + u32 clk_freq; irq = platform_get_irq(pdev, 0); if (irq < 0) { @@ -151,6 +152,9 @@ static int dw_i2c_probe(struct platform_device *pdev) return PTR_ERR(dev->clk); clk_prepare_enable(dev->clk); + /* fast mode by default because of legacy reasons */ + clk_freq = 400000; + if (pdev->dev.of_node) { u32 ht = 0; u32 ic_clk = dev->get_clk_rate_khz(dev); @@ -166,6 +170,17 @@ static int dw_i2c_probe(struct platform_device *pdev) of_property_read_u32(pdev->dev.of_node, "i2c-scl-falling-time-ns", &dev->scl_falling_time); + + of_property_read_u32(pdev->dev.of_node, "clock-frequency", + &clk_freq); + + /* Only standard mode at 100kHz and fast mode at 400kHz + * are supported. + */ + if (clk_freq != 100000 && clk_freq != 400000) { + dev_err(&pdev->dev, "Only 100kHz and 400kHz supported"); + return -EINVAL; + } } dev->functionality = @@ -175,8 +190,12 @@ static int dw_i2c_probe(struct platform_device *pdev) I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_I2C_BLOCK; - dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | - DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; + if (clk_freq == 100000) + dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | + DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD; + else + dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | + DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; /* Try first if we can configure the device from ACPI */ r = dw_i2c_acpi_configure(pdev);