Thread (28 messages) 28 messages, 3 authors, 2015-08-07

[PATCH v6 5/9] clk: mediatek: Fix rate and dependency of MT8173 clocks

From: James Liao <hidden>
Date: 2015-08-06 08:35:39
Also in: linux-devicetree, linux-mediatek, lkml

Hi Sascha,

On Wed, 2015-08-05 at 08:53 +0200, Sascha Hauer wrote:
On Tue, Aug 04, 2015 at 04:16:54PM +0800, James Liao wrote:
quoted
-static const struct mtk_fixed_factor root_clk_alias[] __initconst = {
-	FACTOR(CLK_TOP_CLKPH_MCK_O, "clkph_mck_o", "clk_null", 1, 1),
-	FACTOR(CLK_TOP_USB_SYSPLL_125M, "usb_syspll_125m", "clk_null", 1, 1),
-	FACTOR(CLK_TOP_HDMITX_DIG_CTS, "hdmitx_dig_cts", "clk_null", 1, 1),
+static const struct mtk_fixed_clk fixed_clks[] __initconst = {
+	FIXED_CLK(CLK_TOP_CLKPH_MCK_O, "clkph_mck_o", "clk26m", 400 * MHZ),
+	FIXED_CLK(CLK_TOP_USB_SYSPLL_125M, "usb_syspll_125m", "clk26m", 125 * MHZ),
Hm, it seems you hide PLLs in fixed factor clock. Are you sure that
there is a PLL in the system generating 125MHz from 26MHz which is in no
way configurable? Or is this really some clock derived from the syspll
as the clock name suggests?
According to the datasheet from our clock designer, usb_syspll_125m is
the output clock of an analog macro which is named SSUSB_PHY, and its
input clock is AD_CLK26M_CK.

SSUSB_PHY is not the same as general PLLs such as MAINPLL. So I don't
treat it as a configurable PLL but a fixed clock with the typical rate
125 MHz.


Best regards,

James
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