[PATCH v2 05/21] clk: imx: pllv3: add enable() support

Lukasz Majewski
2020-01-28T08:14:20Z

Hi Giulio,

> Before set_rate() pllv3 needs enable() to power the pll up.
> Add enable() taking into account different power_bit and
> different powerup_set, because some pll needs its power_bit to be
> set or reset to be powered on.

I do guess that this code is similar to what we do have in the Linux
kernel (and which I've probably omitted as it was not needed in the
i.MX6Q use case)?

>
> Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
> ---
> drivers/clk/imx/clk-pllv3.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/clk/imx/clk-pllv3.c b/drivers/clk/imx/clk-pllv3.c
> index 02c75c37ea..d8cbe3dd4e 100644
> --- a/drivers/clk/imx/clk-pllv3.c
> +++ b/drivers/clk/imx/clk-pllv3.c
> @@ -16,9 +16,13 @@
> #define UBOOT_DM_CLK_IMX_PLLV3_GENERIC "imx_clk_pllv3_generic"
> #define UBOOT_DM_CLK_IMX_PLLV3_USB "imx_clk_pllv3_usb"
>
> +#define BM_PLL_POWER (0x1 << 12)
> +
> struct clk_pllv3 {
> struct clk clk;
> void __iomem *base;
> + u32 power_bit;
> + bool powerup_set;
> u32 div_mask;
> u32 div_shift;
> };
> @@ -35,8 +39,24 @@ static ulong clk_pllv3_generic_get_rate(struct clk
> *clk) return (div == 1) ? parent_rate * 22 : parent_rate * 20;
> }
>
> +static int clk_pllv3_generic_enable(struct clk *clk)
> +{
> + struct clk_pllv3 *pll = to_clk_pllv3(clk);
> + u32 val;
> +
> + val = readl(pll->base);
> + if (pll->powerup_set)
> + val |= pll->power_bit;
> + else
> + val &= ~pll->power_bit;
> + writel(val, pll->base);
> +
> + return 0;
> +}
> +
> static const struct clk_ops clk_pllv3_generic_ops = {
> .get_rate = clk_pllv3_generic_get_rate,
> + .enable = clk_pllv3_generic_enable,
> };
>
> struct clk *imx_clk_pllv3(enum imx_pllv3_type type, const char *name,
> @@ -52,14 +72,18 @@ struct clk *imx_clk_pllv3(enum imx_pllv3_type
> type, const char *name, if (!pll)
> return ERR_PTR(-ENOMEM);
>
> + pll->power_bit = BM_PLL_POWER;
> +
> switch (type) {
> case IMX_PLLV3_GENERIC:
> drv_name = UBOOT_DM_CLK_IMX_PLLV3_GENERIC;
> pll->div_shift = 0;
> + pll->powerup_set = false;
> break;
> case IMX_PLLV3_USB:
> drv_name = UBOOT_DM_CLK_IMX_PLLV3_USB;
> pll->div_shift = 1;
> + pll->powerup_set = true;
> break;
> default:
> kfree(pll);

Best regards,

Lukasz Majewski

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