On 11/13/2012 02:41 PM, Thierry Reding wrote: > * PGP Signed by an unknown key > > On Tue, Nov 13, 2012 at 12:38:34PM +0800, Mark Zhang wrote: >> On 11/12/2012 05:39 PM, Mark Zhang wrote: >>> On 11/09/2012 09:20 PM, Thierry Reding wrote: > [...] >>>> @@ -1036,9 +1041,6 @@ static struct clk_duplicate tegra_clk_duplicates[] = { >>>> CLK_DUPLICATE("usbd", "utmip-pad", NULL), >>>> CLK_DUPLICATE("usbd", "tegra-ehci.0", NULL), >>>> CLK_DUPLICATE("usbd", "tegra-otg", NULL), >>>> - CLK_DUPLICATE("hdmi", "tegradc.0", "hdmi"), >>>> - CLK_DUPLICATE("hdmi", "tegradc.1", "hdmi"), >>>> - CLK_DUPLICATE("host1x", "tegra_grhost", "host1x"), >>>> CLK_DUPLICATE("2d", "tegra_grhost", "gr2d"), >>>> CLK_DUPLICATE("3d", "tegra_grhost", "gr3d"), >>>> CLK_DUPLICATE("epp", "tegra_grhost", "epp"), >>>> @@ -1051,6 +1053,9 @@ static struct clk_duplicate tegra_clk_duplicates[] = { >>>> CLK_DUPLICATE("pll_p_out3", "tegra-i2c.1", "fast-clk"), >>>> CLK_DUPLICATE("pll_p_out3", "tegra-i2c.2", "fast-clk"), >>>> CLK_DUPLICATE("pll_p_out3", "tegra-i2c.3", "fast-clk"), >>>> + CLK_DUPLICATE("pll_p", "tegra-dc.0", "parent"), >>>> + CLK_DUPLICATE("pll_p", "tegra-dc.1", "parent"), >>>> + CLK_DUPLICATE("pll_d_out0", "tegra-hdmi", "parent"), >>>> }; >> >> Why we need this "CLK_DUPLICATE"? Set the clock parent of the dc >> controllers to pll_p? > > This was the method proposed by Stephen to abstract away the clock tree > differences between Tegra20 and Tegra30. The way this works is that we > can {devm_,}clk_get(&pdev->dev, "parent") in the display and HDMI > controllers' .probe() and it'll obtain the correct parent clock > independent of which version of Tegra is used. > Yes, after reading the corresponding codes in rgb.c & hdmi.c, I got how this works. It's better than our previous version, I mean, the version which we hard-code the clock parent setting logics in clock.c. But I wanna say, it looks weird if you don't read the code of drm driver. > Thierry > > * Unknown Key > * 0x7F3EB3A1 > -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html