[PATCH v2 01/17] clk: imx: composite-8m: Enable gate clk with mcore_booted

Peng Fan peng.fan at nxp.com
Mon May 13 01:31:22 PDT 2024


> Subject: Re: [PATCH v2 01/17] clk: imx: composite-8m: Enable gate clk with
> mcore_booted
>
> On Fri, May 10, 2024 at 05:18:56PM +0800, Peng Fan (OSS) wrote:
> > From: Peng Fan <peng.fan at nxp.com>
> >
> > Bootloader might disable some CCM ROOT Slices. So if mcore_booted set
> > with display CCM ROOT disabled by Bootloader, kernel display BLK CTRL
> > driver imx8m_blk_ctrl_driver_init may hang the system because the BUS
> > clk is disabled.
> >
> > Add back gate ops, but with disable doing nothing, then the CCM ROOT
> > will be enabled when used.
> >
> > Fixes: 489bbee0c983 ("clk: imx: composite-8m: Enable gate clk with
> > mcore_booted")
>
> I can't find this commitish anywhere, also the subject looks like this patch
> fixes itself.

My bad. Picked the first commit when I use --pretty=fixes.

>
> > Reviewed-by: Ye Li <ye.li at nxp.com>
> > Reviewed-by: Jacky Bai <ping.bai at nxp.com>
> > Signed-off-by: Peng Fan <peng.fan at nxp.com>
> > ---
> >  drivers/clk/imx/clk-composite-8m.c | 53
> > ++++++++++++++++++++++++++++++--------
> >  1 file changed, 42 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/clk/imx/clk-composite-8m.c
> > b/drivers/clk/imx/clk-composite-8m.c
> > index 8cc07d056a83..f187582ba491 100644
> > --- a/drivers/clk/imx/clk-composite-8m.c
> > +++ b/drivers/clk/imx/clk-composite-8m.c
> > @@ -204,6 +204,34 @@ static const struct clk_ops
> imx8m_clk_composite_mux_ops = {
> >     .determine_rate = imx8m_clk_composite_mux_determine_rate,
> >  };
> >
> > +static int imx8m_clk_composite_gate_enable(struct clk_hw *hw) {
> > +   struct clk_gate *gate = to_clk_gate(hw);
> > +   unsigned long flags;
> > +   u32 val;
> > +
> > +   spin_lock_irqsave(gate->lock, flags);
> > +
> > +   val = readl(gate->reg);
> > +   val |= BIT(gate->bit_idx);
> > +   writel(val, gate->reg);
> > +
> > +   spin_unlock_irqrestore(gate->lock, flags);
> > +
> > +   return 0;
> > +}
> > +
> > +static void imx8m_clk_composite_gate_disable(struct clk_hw *hw) {
> > +   /* composite clk requires the disable hook */ }
> > +
> > +static const struct clk_ops imx8m_clk_composite_gate_ops = {
> > +   .enable = imx8m_clk_composite_gate_enable,
> > +   .disable = imx8m_clk_composite_gate_disable,
> > +   .is_enabled = clk_gate_is_enabled,
> > +};
> > +
> >  struct clk_hw *__imx8m_clk_hw_composite(const char *name,
> >                                     const char * const *parent_names,
> >                                     int num_parents, void __iomem
> *reg, @@ -217,6 +245,7 @@ struct
> > clk_hw *__imx8m_clk_hw_composite(const char *name,
> >     struct clk_mux *mux;
> >     const struct clk_ops *divider_ops;
> >     const struct clk_ops *mux_ops;
> > +   const struct clk_ops *gate_ops;
> >
> >     mux = kzalloc(sizeof(*mux), GFP_KERNEL);
> >     if (!mux)
> > @@ -257,20 +286,22 @@ struct clk_hw
> *__imx8m_clk_hw_composite(const char *name,
> >     div->flags = CLK_DIVIDER_ROUND_CLOSEST;
> >
> >     /* skip registering the gate ops if M4 is enabled */
>
> This comment doesn't seems to become inaccurate with this patch.

Right. Drop it in v3.

>
> > -   if (!mcore_booted) {
> > -           gate = kzalloc(sizeof(*gate), GFP_KERNEL);
> > -           if (!gate)
> > -                   goto free_div;
> > -
> > -           gate_hw = &gate->hw;
> > -           gate->reg = reg;
> > -           gate->bit_idx = PCG_CGC_SHIFT;
> > -           gate->lock = &imx_ccm_lock;
> > -   }
> > +   gate = kzalloc(sizeof(*gate), GFP_KERNEL);
> > +   if (!gate)
> > +           goto free_div;
> > +
> > +   gate_hw = &gate->hw;
> > +   gate->reg = reg;
> > +   gate->bit_idx = PCG_CGC_SHIFT;
> > +   gate->lock = &imx_ccm_lock;
> > +   if (!mcore_booted)
> > +           gate_ops = &clk_gate_ops;
> > +   else
> > +           gate_ops = &imx8m_clk_composite_gate_ops;
>
> Please use positive logic. It's easier to read.

Sure. update in v3.

Thanks,
Peng.
>
> Sascha
>
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