RE: [PATCH V2 2/3] ARM: clk-imx6q: Add missing lvds and anaclk clock to the clock tree

["shengjiu.wang@freescale.com" <shengjiu.wang@freescale.com>]

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Hi Stash, Shawn

  Do we have such API for exclusive clock? Or Do you have example for these exclusive clocks?

Best regards
Wang shengjiu

-----Original Message-----
From: Lucas Stach [mailto:l.stach@pengutronix.de] 
Sent: Wednesday, August 06, 2014 10:42 PM
To: Wang Shengjiu-B02247
Cc: Guo Shawn-R65073; kernel@pengutronix.de; linux@arm.linux.org.uk; robh+dt@kernel.org; pawel.moll@arm.com; mark.rutland@arm.com; ijc+devicetree@hellion.org.uk; galak@codeaurora.org; Chen Guangyu-B42378; linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH V2 2/3] ARM: clk-imx6q: Add missing lvds and anaclk clock to the clock tree

Am Mittwoch, den 06.08.2014, 16:35 +0800 schrieb Shengjiu Wang:
> anaclk1 and anaclk2 is the clock source for lvds1_in and lvds2_in. 
> lvds1_in and lvds2_in can be used to provide external clock source to 
> the internal pll, such as pll4_audio and pll5_video.
> pll4_audio and pll5_video can have multiple source, not only "osc", so 
> add them.
> 
> Signed-off-by: Nicolin Chen <Guangyu.Chen@freescale.com>
> Signed-off-by: Shengjiu Wang <shengjiu.wang@freescale.com>
> ---
>  arch/arm/mach-imx/clk-imx6q.c             |   12 ++++++++++--
>  include/dt-bindings/clock/imx6qdl-clock.h |    8 +++++++-
>  2 files changed, 17 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/mach-imx/clk-imx6q.c 
> b/arch/arm/mach-imx/clk-imx6q.c index 1d6dd59..330aad3 100644
> --- a/arch/arm/mach-imx/clk-imx6q.c
> +++ b/arch/arm/mach-imx/clk-imx6q.c
> @@ -73,6 +73,7 @@ static const char *lvds_sels[] = {
>  	"pll4_audio", "pll5_video", "pll8_mlb", "enet_ref",
>  	"pcie_ref_125m", "sata_ref_100m",
>  };
> +static const char *pll_av_sels[] = { "osc", "lvds1_in", "lvds2_in", 
> +"dummy", };
>  
>  static struct clk *clk[IMX6QDL_CLK_END];  static struct 
> clk_onecell_data clk_data; @@ -119,6 +120,9 @@ static void __init 
> imx6q_clocks_init(struct device_node *ccm_node)
>  	clk[IMX6QDL_CLK_CKIL] = imx_obtain_fixed_clock("ckil", 0);
>  	clk[IMX6QDL_CLK_CKIH] = imx_obtain_fixed_clock("ckih1", 0);
>  	clk[IMX6QDL_CLK_OSC] = imx_obtain_fixed_clock("osc", 0);
> +	/* Clock source from external clock via ANACLK1/2 PADs */
> +	clk[IMX6QDL_CLK_ANACLK1] = imx_obtain_fixed_clock("anaclk1", 0);
> +	clk[IMX6QDL_CLK_ANACLK2] = imx_obtain_fixed_clock("anaclk2", 0);
>  
>  	np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-anatop");
>  	base = of_iomap(np, 0);
> @@ -136,8 +140,8 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
>  	clk[IMX6QDL_CLK_PLL1_SYS]      = imx_clk_pllv3(IMX_PLLV3_SYS,	"pll1_sys",	"osc", base,        0x7f);
>  	clk[IMX6QDL_CLK_PLL2_BUS]      = imx_clk_pllv3(IMX_PLLV3_GENERIC,	"pll2_bus",	"osc", base + 0x30, 0x1);
>  	clk[IMX6QDL_CLK_PLL3_USB_OTG]  = imx_clk_pllv3(IMX_PLLV3_USB,	"pll3_usb_otg",	"osc", base + 0x10, 0x3);
> -	clk[IMX6QDL_CLK_PLL4_AUDIO]    = imx_clk_pllv3(IMX_PLLV3_AV,	"pll4_audio",	"osc", base + 0x70, 0x7f);
> -	clk[IMX6QDL_CLK_PLL5_VIDEO]    = imx_clk_pllv3(IMX_PLLV3_AV,	"pll5_video",	"osc", base + 0xa0, 0x7f);
> +	clk[IMX6QDL_CLK_PLL4_AUDIO]    = imx_clk_pllv3(IMX_PLLV3_AV,	"pll4_audio",	"pll4_sel", base + 0x70, 0x7f);
> +	clk[IMX6QDL_CLK_PLL5_VIDEO]    = imx_clk_pllv3(IMX_PLLV3_AV,	"pll5_video",	"pll5_sel", base + 0xa0, 0x7f);
>  	clk[IMX6QDL_CLK_PLL6_ENET]     = imx_clk_pllv3(IMX_PLLV3_ENET,	"pll6_enet",	"osc", base + 0xe0, 0x3);
>  	clk[IMX6QDL_CLK_PLL7_USB_HOST] = imx_clk_pllv3(IMX_PLLV3_USB,	"pll7_usb_host","osc", base + 0x20, 0x3);
>  
> @@ -169,6 +173,8 @@ static void __init imx6q_clocks_init(struct 
> device_node *ccm_node)
>  
>  	clk[IMX6QDL_CLK_LVDS1_SEL] = imx_clk_mux("lvds1_sel", base + 0x160, 0, 5, lvds_sels, ARRAY_SIZE(lvds_sels));
>  	clk[IMX6QDL_CLK_LVDS2_SEL] = imx_clk_mux("lvds2_sel", base + 0x160, 
> 5, 5, lvds_sels, ARRAY_SIZE(lvds_sels));
> +	clk[IMX6QDL_CLK_PLL4_SEL]  = imx_clk_mux("pll4_sel",  base + 0x70, 14, 2, pll_av_sels, ARRAY_SIZE(pll_av_sels));
> +	clk[IMX6QDL_CLK_PLL5_SEL]  = imx_clk_mux("pll5_sel",  base + 0xa0, 
> +14, 2, pll_av_sels, ARRAY_SIZE(pll_av_sels));
>  
>  	/*
>  	 * lvds1_gate and lvds2_gate are pseudo-gates.  Both can be @@ 
> -178,6 +184,8 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
>  	 */
>  	clk[IMX6QDL_CLK_LVDS1_GATE] = imx_clk_gate("lvds1_gate", "lvds1_sel", base + 0x160, 10);
>  	clk[IMX6QDL_CLK_LVDS2_GATE] = imx_clk_gate("lvds2_gate", 
> "lvds2_sel", base + 0x160, 11);
> +	clk[IMX6QDL_CLK_LVDS1_IN] = imx_clk_gate("lvds1_in", "anaclk1", base + 0x160, 12);
> +	clk[IMX6QDL_CLK_LVDS2_IN] = imx_clk_gate("lvds2_in", "anaclk2", base 
> ++ 0x160, 13);
>  
I think we need something more clever here. With both lvds in and out modeled as a clock gate it is possible for the user to enable both at the same time. The reference manual on the contrary states that both states are mutually exclusive: "Do not enable input and output buffers simultaneously".

Regards,
Lucas
-- 
Pengutronix e.K.             | Lucas Stach                 |
Industrial Linux Solutions   | http://www.pengutronix.de/  |

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