Re: [PATCH 23/40] ARM i.MX: Add common clock support for 2bit gate

[Domenico Andreoli <cavokz@xxxxxxxxx>]

On Thu, Apr 19, 2012 at 03:26:53PM +0800, Lei Wen wrote:
> On Thu, Apr 19, 2012 at 3:00 PM, Shawn Guo <shawn.guo@xxxxxxxxxxxxx> wrote:
> > On Tue, Apr 10, 2012 at 03:45:36PM +0200, Sascha Hauer wrote:
> > [snip]
> >> +struct clk *clk_register_gate2(struct device *dev, const char *name,
> >> +             const char *parent_name, unsigned long flags,
> >> +             void __iomem *reg, u8 bit_idx,
> >> +             u8 clk_gate2_flags, spinlock_t *lock)
> >> +{
> >> +     struct clk_gate *gate;
> >> +     struct clk *clk;
> >> +
> >> +     gate = kzalloc(sizeof(struct clk_gate), GFP_KERNEL);
> >> +
> >> +     if (!gate) {
> >> +             pr_err("%s: could not allocate gated clk\n", __func__);
> >> +             return NULL;
> >> +     }
> >> +
> >> +     /* struct clk_gate assignments */
> >> +     gate->reg = reg;
> >> +     gate->bit_idx = bit_idx;
> >> +     gate->flags = clk_gate2_flags;
> >> +     gate->lock = lock;
> >> +
> >> +     if (parent_name) {
> >> +             gate->parent[0] = kstrdup(parent_name, GFP_KERNEL);
> >> +             if (!gate->parent[0])
> >> +                     goto out;
> >> +     }
> >> +
> >> +     clk = clk_register(dev, name,
> >> +                     &clk_gate2_ops, &gate->hw,
> >> +                     gate->parent,
> >> +                     (parent_name ? 1 : 0),
> >> +                     flags);
> > Why do you re-use struct clk_gate while you don't use clk_gate_ops?
> > It doesn't follow object oriented thought. struct clk_gate may change
> > according to clk_gate_ops changes.
> >
> > Thanks
> > Richard
> >
> >
> >
> 
> Why not expend original clk-gate.c to allow set more than one bit a
> time to gate that clock?
> At least in my platform, some clock need 12bit to get its gate mode,
> which means that module
> has more than one clock concurrently up to work, and only a part of
> that group work cannot lead
> to a correct working mode. This also means those bits need to turn
> on/off at the same time.

I would also need a double gate, one reg to enable and one to disable,
both or-ing the same bitmask. I think this can be addressed in the
flags but what about a union to store the different regs, widths, shifts?

thanks,
Domenico

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