Re: [PATCH v3 13/31] clk: mediatek: pll: Implement unregister API

Chun-Jie Chen
2022-02-15T06:34:03Z

On Tue, 2022-02-08 at 20:40 +0800, Chen-Yu Tsai wrote:
> The PLL clk type within the MediaTek clk driver library only has a
> register function, and no corresponding unregister function. This
> means there is no way for its users to properly implement cleanup
> and removal.
>
> Add a matching unregister function for the PLL type clk.
>
> Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
> Reviewed-by: Miles Chen <miles.chen@mediatek.com>
> Reviewed-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@collabora.com>

Reviewed-by: Chun-Jie Chen <chun-jie.chen@mediatek.com>
> ---
> drivers/clk/mediatek/clk-pll.c | 55
> ++++++++++++++++++++++++++++++++++
> drivers/clk/mediatek/clk-pll.h | 2 ++
> 2 files changed, 57 insertions(+)
>
> diff --git a/drivers/clk/mediatek/clk-pll.c
> b/drivers/clk/mediatek/clk-pll.c
> index 64f59554bc9b..b54e33b75d4e 100644
> --- a/drivers/clk/mediatek/clk-pll.c
> +++ b/drivers/clk/mediatek/clk-pll.c
> @@ -360,6 +360,21 @@ static struct clk *mtk_clk_register_pll(const
> struct mtk_pll_data *data,
> return clk;
> }
>
> +static void mtk_clk_unregister_pll(struct clk *clk)
> +{
> + struct clk_hw *hw;
> + struct mtk_clk_pll *pll;
> +
> + hw = __clk_get_hw(clk);
> + if (!hw)
> + return;
> +
> + pll = to_mtk_clk_pll(hw);
> +
> + clk_unregister(clk);
> + kfree(pll);
> +}
> +
> void mtk_clk_register_plls(struct device_node *node,
> const struct mtk_pll_data *plls, int num_plls, struct
> clk_onecell_data *clk_data)
> {
> @@ -388,4 +403,44 @@ void mtk_clk_register_plls(struct device_node
> *node,
> }
> EXPORT_SYMBOL_GPL(mtk_clk_register_plls);
>
> +static __iomem void *mtk_clk_pll_get_base(struct clk *clk,
> + const struct mtk_pll_data
> *data)
> +{
> + struct clk_hw *hw = __clk_get_hw(clk);
> + struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
> +
> + return pll->base_addr - data->reg;
> +}
> +
> +void mtk_clk_unregister_plls(const struct mtk_pll_data *plls, int
> num_plls,
> + struct clk_onecell_data *clk_data)
> +{
> + __iomem void *base = NULL;
> + int i;
> +
> + if (!clk_data)
> + return;
> +
> + for (i = num_plls; i > 0; i--) {
> + const struct mtk_pll_data *pll = &plls[i - 1];
> +
> + if (IS_ERR_OR_NULL(clk_data->clks[pll->id]))
> + continue;
> +
> + /*
> + * This is quite ugly but unfortunately the clks don't
> have
> + * any device tied to them, so there's no place to
> store the
> + * pointer to the I/O region base address. We have to
> fetch
> + * it from one of the registered clks.
> + */
> + base = mtk_clk_pll_get_base(clk_data->clks[pll->id],
> pll);
> +
> + mtk_clk_unregister_pll(clk_data->clks[pll->id]);
> + clk_data->clks[pll->id] = ERR_PTR(-ENOENT);
> + }
> +
> + iounmap(base);
> +}
> +EXPORT_SYMBOL_GPL(mtk_clk_unregister_plls);
> +
> MODULE_LICENSE("GPL");
> diff --git a/drivers/clk/mediatek/clk-pll.h
> b/drivers/clk/mediatek/clk-pll.h
> index d01b0c38311d..a889b1e472e7 100644
> --- a/drivers/clk/mediatek/clk-pll.h
> +++ b/drivers/clk/mediatek/clk-pll.h
> @@ -51,5 +51,7 @@ struct mtk_pll_data {
> void mtk_clk_register_plls(struct device_node *node,
> const struct mtk_pll_data *plls, int
> num_plls,
> struct clk_onecell_data *clk_data);
> +void mtk_clk_unregister_plls(const struct mtk_pll_data *plls, int
> num_plls,
> + struct clk_onecell_data *clk_data);
>
> #endif /* __DRV_CLK_MTK_PLL_H */