The mux 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 mux type clk.

Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
---
 drivers/clk/mediatek/clk-mux.c | 35 ++++++++++++++++++++++++++++++++++
 drivers/clk/mediatek/clk-mux.h |  3 +++
 2 files changed, 38 insertions(+)

diff --git a/drivers/clk/mediatek/clk-mux.c b/drivers/clk/mediatek/clk-mux.c
index 89f23e111d91..6f0c22a699c3 100644
--- a/drivers/clk/mediatek/clk-mux.c
+++ b/drivers/clk/mediatek/clk-mux.c
@@ -164,6 +164,21 @@ static struct clk *mtk_clk_register_mux(const struct mtk_mux *mux,
 	return clk;
 }
 
+static void mtk_clk_unregister_mux(struct clk *clk)
+{
+	struct mtk_clk_mux *mux;
+	struct clk_hw *hw;
+
+	hw = __clk_get_hw(clk);
+	if (!hw)
+		return;
+
+	mux = to_mtk_clk_mux(hw);
+
+	clk_unregister(clk);
+	kfree(mux);
+}
+
 int mtk_clk_register_muxes(const struct mtk_mux *muxes,
 			   int num, struct device_node *node,
 			   spinlock_t *lock,
@@ -198,4 +213,24 @@ int mtk_clk_register_muxes(const struct mtk_mux *muxes,
 }
 EXPORT_SYMBOL_GPL(mtk_clk_register_muxes);
 
+void mtk_clk_unregister_muxes(const struct mtk_mux *muxes, int num,
+			      struct clk_onecell_data *clk_data)
+{
+	int i;
+
+	if (!clk_data)
+		return;
+
+	for (i = num; i > 0; i--) {
+		const struct mtk_mux *mux = &muxes[i - 1];
+
+		if (IS_ERR_OR_NULL(clk_data->clks[mux->id]))
+			continue;
+
+		mtk_clk_unregister_mux(clk_data->clks[mux->id]);
+		clk_data->clks[mux->id] = ERR_PTR(-ENOENT);
+	}
+}
+EXPORT_SYMBOL_GPL(mtk_clk_unregister_muxes);
+
 MODULE_LICENSE("GPL");
diff --git a/drivers/clk/mediatek/clk-mux.h b/drivers/clk/mediatek/clk-mux.h
index 27841d649118..cb2ac4f04c58 100644
--- a/drivers/clk/mediatek/clk-mux.h
+++ b/drivers/clk/mediatek/clk-mux.h
@@ -88,4 +88,7 @@ int mtk_clk_register_muxes(const struct mtk_mux *muxes,
 			   spinlock_t *lock,
 			   struct clk_onecell_data *clk_data);
 
+void mtk_clk_unregister_muxes(const struct mtk_mux *muxes, int num,
+			      struct clk_onecell_data *clk_data);
+
 #endif /* __DRV_CLK_MTK_MUX_H */
-- 
2.35.0.rc0.227.g00780c9af4-goog

> The mux 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 mux type clk.
> 
> Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>

Reviewed-by: Miles Chen <miles.chen@mediatek.com>

> ---
>  drivers/clk/mediatek/clk-mux.c | 35 ++++++++++++++++++++++++++++++++++
>  drivers/clk/mediatek/clk-mux.h |  3 +++
>  2 files changed, 38 insertions(+)
> 
> diff --git a/drivers/clk/mediatek/clk-mux.c b/drivers/clk/mediatek/clk-mux.c
> index 89f23e111d91..6f0c22a699c3 100644
> --- a/drivers/clk/mediatek/clk-mux.c
> +++ b/drivers/clk/mediatek/clk-mux.c
> @@ -164,6 +164,21 @@ static struct clk *mtk_clk_register_mux(const struct mtk_mux *mux,
>  	return clk;
>  }
>  
> +static void mtk_clk_unregister_mux(struct clk *clk)
> +{
> +	struct mtk_clk_mux *mux;
> +	struct clk_hw *hw;
> +
> +	hw = __clk_get_hw(clk);
> +	if (!hw)
> +		return;
> +
> +	mux = to_mtk_clk_mux(hw);
> +
> +	clk_unregister(clk);
> +	kfree(mux);
> +}
> +
>  int mtk_clk_register_muxes(const struct mtk_mux *muxes,
>  			   int num, struct device_node *node,
>  			   spinlock_t *lock,
> @@ -198,4 +213,24 @@ int mtk_clk_register_muxes(const struct mtk_mux *muxes,
>  }
>  EXPORT_SYMBOL_GPL(mtk_clk_register_muxes);
>  
> +void mtk_clk_unregister_muxes(const struct mtk_mux *muxes, int num,
> +			      struct clk_onecell_data *clk_data)
> +{
> +	int i;
> +
> +	if (!clk_data)
> +		return;
> +
> +	for (i = num; i > 0; i--) {
> +		const struct mtk_mux *mux = &muxes[i - 1];
> +
> +		if (IS_ERR_OR_NULL(clk_data->clks[mux->id]))
> +			continue;
> +
> +		mtk_clk_unregister_mux(clk_data->clks[mux->id]);
> +		clk_data->clks[mux->id] = ERR_PTR(-ENOENT);
> +	}
> +}
> +EXPORT_SYMBOL_GPL(mtk_clk_unregister_muxes);
> +
>  MODULE_LICENSE("GPL");
> diff --git a/drivers/clk/mediatek/clk-mux.h b/drivers/clk/mediatek/clk-mux.h
> index 27841d649118..cb2ac4f04c58 100644
> --- a/drivers/clk/mediatek/clk-mux.h
> +++ b/drivers/clk/mediatek/clk-mux.h
> @@ -88,4 +88,7 @@ int mtk_clk_register_muxes(const struct mtk_mux *muxes,
>  			   spinlock_t *lock,
>  			   struct clk_onecell_data *clk_data);
>  
> +void mtk_clk_unregister_muxes(const struct mtk_mux *muxes, int num,
> +			      struct clk_onecell_data *clk_data);
> +
>  #endif /* __DRV_CLK_MTK_MUX_H */
> -- 
> 2.35.0.rc0.227.g00780c9af4-goog

> +static void mtk_clk_unregister_pll(struct clk *clk)
> +{
> +	struct clk_hw *hw = __clk_get_hw(clk);
> +	struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
> +
> +	clk_unregister(clk);
> +	kfree(pll);
> +}
> +

mtk_clk_unregister_pll() looks different. 
Do we need to check hw before passing it to to_mtk_clk_pll(hw), like
mtk_clk_unregister_mux()?

>  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 +397,44 @@ 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 */
> -- 
> 2.35.0.rc0.227.g00780c9af4-goog

On Wed, Jan 26, 2022 at 2:04 PM Miles Chen <miles.chen@mediatek.com> wrote:
>
> > +static void mtk_clk_unregister_pll(struct clk *clk)
> > +{
> > +     struct clk_hw *hw = __clk_get_hw(clk);
> > +     struct mtk_clk_pll *pll = to_mtk_clk_pll(hw);
> > +
> > +     clk_unregister(clk);
> > +     kfree(pll);
> > +}
> > +
>
> mtk_clk_unregister_pll() looks different.
> Do we need to check hw before passing it to to_mtk_clk_pll(hw), like
> mtk_clk_unregister_mux()?

Good catch.

In theory we should, since __get_clk_hw() would return NULL if clk is NULL.
However the code already does that check before it calls
mtk_clk_unregister_pll(), so the code is safe. We should make everything
consistent though.

I might have written the code on separate days and thus introduced some
discrepancies. I'll fix it in v2.


ChenYu

> >  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 +397,44 @@ 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 */
> > --
> > 2.35.0.rc0.227.g00780c9af4-goog
>
>