[PATCH V2] ARM: imx: correct usecount of IPG, ARM and MMDC clk on i.mx6sl

[s.hauer@pengutronix.de (Sascha Hauer)]

On Tue, Jan 21, 2014 at 06:50:52PM +0800, Anson Huang wrote:
> IPG, ARM and MMDC's clock should be enabled during kernel boot up,
> so we need to maintain their use count, otherwise, they may be
> disabled unexpectedly if their children's clock are turned off,
> which is not allowed.
> 
> Signed-off-by: Anson Huang <b20788@freescale.com>
> ---
>  arch/arm/mach-imx/clk-imx6sl.c |   16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/arch/arm/mach-imx/clk-imx6sl.c b/arch/arm/mach-imx/clk-imx6sl.c
> index 78f3bd6..047f4ff 100644
> --- a/arch/arm/mach-imx/clk-imx6sl.c
> +++ b/arch/arm/mach-imx/clk-imx6sl.c
> @@ -291,6 +291,22 @@ static void __init imx6sl_clocks_init(struct device_node *ccm_node)
>  		pr_warn("%s: failed to set AHB clock rate %d!\n",
>  			__func__, ret);
>  
> +	/*
> +	 * Make sure those always on clocks are enabled to maintain the correct
> +	 * usecount and enabling/disabling of parent PLLs.
> +	 */
> +	ret = clk_prepare_enable(clks[IMX6SL_CLK_IPG]);
> +	if (ret)
> +		pr_warn("%s: failed to enable IPG clock %d\n", __func__, ret);
> +
> +	ret = clk_prepare_enable(clks[IMX6SL_CLK_ARM]);
> +	if (ret)
> +		pr_warn("%s: failed to enable ARM clock %d\n", __func__, ret);
> +
> +	ret = clk_prepare_enable(clks[IMX6SL_CLK_MMDC_ROOT]);
> +	if (ret)
> +		pr_warn("%s: failed to enable MMDC clock %d\n", __func__, ret);
> +

Consider using a clk_init_on array like we have in clk-imx6q.c

Sascha

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