| Message ID | 1243436086-3623-2-git-send-email-aaro.koskinen@nokia.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream, archived |
| Delegated to: | Tony Lindgren |
| Headers | show |
* Aaro Koskinen <aaro.koskinen@nokia.com> [090527 07:55]: > Use longer noise filter period for fast and standard mode. Based on an > earlier patch by Eero Nurkkala. > > Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com> Ben this should be queued too. Acked-by: Tony Lindgren <tony@atomide.com> > --- > drivers/i2c/busses/i2c-omap.c | 14 ++++++++++++-- > 1 files changed, 12 insertions(+), 2 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c > index 5d9880c..8c76cea 100644 > --- a/drivers/i2c/busses/i2c-omap.c > +++ b/drivers/i2c/busses/i2c-omap.c > @@ -333,8 +333,18 @@ static int omap_i2c_init(struct omap_i2c_dev *dev) > > if (cpu_is_omap2430() || cpu_is_omap34xx()) { > > - /* HSI2C controller internal clk rate should be 19.2 Mhz */ > - internal_clk = 19200; > + /* > + * HSI2C controller internal clk rate should be 19.2 Mhz for > + * HS and for all modes on 2430. On 34xx we can use lower rate > + * to get longer filter period for better noise suppression. > + * The filter is iclk (fclk for HS) period. > + */ > + if (dev->speed > 400 || cpu_is_omap_2430()) > + internal_clk = 19200; > + else if (dev->speed > 100) > + internal_clk = 9600; > + else > + internal_clk = 4000; > fclk_rate = clk_get_rate(dev->fclk) / 1000; > > /* Compute prescaler divisor */ > -- > 1.5.4.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-omap" 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-omap.c b/drivers/i2c/busses/i2c-omap.c index 5d9880c..8c76cea 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -333,8 +333,18 @@ static int omap_i2c_init(struct omap_i2c_dev *dev) if (cpu_is_omap2430() || cpu_is_omap34xx()) { - /* HSI2C controller internal clk rate should be 19.2 Mhz */ - internal_clk = 19200; + /* + * HSI2C controller internal clk rate should be 19.2 Mhz for + * HS and for all modes on 2430. On 34xx we can use lower rate + * to get longer filter period for better noise suppression. + * The filter is iclk (fclk for HS) period. + */ + if (dev->speed > 400 || cpu_is_omap_2430()) + internal_clk = 19200; + else if (dev->speed > 100) + internal_clk = 9600; + else + internal_clk = 4000; fclk_rate = clk_get_rate(dev->fclk) / 1000; /* Compute prescaler divisor */
Use longer noise filter period for fast and standard mode. Based on an earlier patch by Eero Nurkkala. Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com> --- drivers/i2c/busses/i2c-omap.c | 14 ++++++++++++-- 1 files changed, 12 insertions(+), 2 deletions(-)