Re: [PATCH v2 03/11] ARM: davinci: da850: use clk->set_parent for async3

Sekhar Nori
2016-03-23T15:58:31Z

On Thursday 17 March 2016 07:56 AM, David Lechner wrote:
> The da850 family of processors has an async3 clock domain that can be
> muxed to either pll0_sysclk2 or pll1_sysclk2. Now that the davinci clocks
> have a set_parent callback, we can use this to control the async3 mux
> instead of a stand-alone function.
>
> This adds a new async3_clk and sets the appropriate child clocks. The
> default is use to pll1_sysclk2 since it is not affected by processor
> frequency scaling.
>
> Signed-off-by: David Lechner <david@lechnology.com>
> ---

> +static int da850_async3_set_parent(struct clk *clk, struct clk *parent)
> +{
> + u32 __iomem *cfgchip3;
> + u32 val;
> +
> + /*
> + * Can't use DA8XX_SYSCFG0_VIRT() here since this can be called before
> + * da8xx_syscfg0_base is initialized.
> + */
> + cfgchip3 = ioremap(DA8XX_SYSCFG0_BASE + DA8XX_CFGCHIP3_REG, 4);

Is this just a theoretical possibility or have you seen this happen? I
would like to see if there are ways of avoiding this rather than throw
away usage of DA8XX_SYSCFG0_VIRT()

> + val = readl(cfgchip3);
> +
> + /* Set the USB 1.1 PHY clock mux based on the parent clock. */

Comment is wrong (copy-paste error?)

> + if (parent == &pll0_sysclk2)
> + val &= ~CFGCHIP3_ASYNC3_CLKSRC;
> + else if (parent == &pll1_sysclk2)
> + val |= CFGCHIP3_ASYNC3_CLKSRC;
> + else {
> + pr_err("Bad parent on async3 clock mux.\n");
> + return -EINVAL;
> + }
> +
> + writel(val, cfgchip3);
> +
> + return 0;
> +}

Thanks,
Sekhar