[PATCH v2 1/9] ARM: i.MX28: define osc in DT

[Shawn Guo]

On Fri, Mar 08, 2013 at 10:01:36AM +0100, Steffen Trumtrar wrote:
> From: Juergen Beisert <jbe at pengutronix.de>
> 
> Instead of hardcoding the ref_xtal in the clk driver, get it from the DT.
> 
> Signed-off-by: Juergen Beisert <jbe at pengutronix.de>
> Signed-off-by: Steffen Trumtrar <s.trumtrar at pengutronix.de>
> ---
>  arch/arm/boot/dts/imx28.dtsi | 11 +++++++++++
>  drivers/clk/mxs/clk-imx28.c  | 16 +++++++++++++++-
>  2 files changed, 26 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boot/dts/imx28.dtsi b/arch/arm/boot/dts/imx28.dtsi
> index 7ba4966..b9e3712 100644
> --- a/arch/arm/boot/dts/imx28.dtsi
> +++ b/arch/arm/boot/dts/imx28.dtsi
> @@ -37,6 +37,17 @@
>  		};
>  	};
>  
> +	clocks {
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +
> +		osc24m: system-oscillator {
> +			compatible = "fixed-clock";
> +			#clock-cells = <0>;
> +			clock-frequency = <24000000>;
> +		};
> +	};
> +
>  	apb at 80000000 {
>  		compatible = "simple-bus";
>  		#address-cells = <1>;
> diff --git a/drivers/clk/mxs/clk-imx28.c b/drivers/clk/mxs/clk-imx28.c
> index 76ce6c6..01048b5 100644
> --- a/drivers/clk/mxs/clk-imx28.c
> +++ b/drivers/clk/mxs/clk-imx28.c
> @@ -158,7 +158,21 @@ int __init mx28_clocks_init(void)
>  
>  	clk_misc_init();
>  
> -	clks[ref_xtal] = mxs_clk_fixed("ref_xtal", 24000000);
> +	/* retrieve the crystal's frequencies from device tree */
> +	for_each_compatible_node(np, NULL, "fixed-clock") {
> +		u32 rate;
> +
> +		if (of_property_read_u32(np, "clock-frequency", &rate))
> +			continue;
> +
> +		if (of_device_is_compatible(np, "fsl,mxs-system"))

Use node name to save the custom compatible.

But more fundamental question - do you really have a imx28 system
running a ref_xtal that is not 24 MHz?  Or does imx28 actually support
any other frequency ref_xtal other than 24 MHz?

Shawn

> +			clks[ref_xtal] = mxs_clk_fixed("ref_xtal", rate);
> +	}
> +
> +	/* if not set, guess their frequency */
> +	if (clks[ref_xtal] == NULL)
> +		clks[ref_xtal] = mxs_clk_fixed("ref_xtal", 24000000);
> +
>  	clks[pll0] = mxs_clk_pll("pll0", "ref_xtal", PLL0CTRL0, 17, 480000000);
>  	clks[pll1] = mxs_clk_pll("pll1", "ref_xtal", PLL1CTRL0, 17, 480000000);
>  	clks[pll2] = mxs_clk_pll("pll2", "ref_xtal", PLL2CTRL0, 23, 50000000);
> -- 
> 1.8.2.rc2
>