Re: [PATCH v3 4/5] clk: basic gateable and fixed-rate clks

From: Turquette, Mike
Date: Sun Nov 27 2011 - 01:04:08 EST


On Sat, Nov 26, 2011 at 5:48 AM, Shawn Guo <shawn.guo@xxxxxxxxxxxxx> wrote:
> On Mon, Nov 21, 2011 at 05:40:46PM -0800, Mike Turquette wrote:
>> Many platforms support simple gateable clks and fixed-rate clks that
>> should not be re-implemented by every platform.
>>
>> This patch introduces a gateable clk with a common programming model of
>> gate control via a write of 1 bit to a register.  Both set-to-enable and
>> clear-to-enable are supported.
>>
>> Also introduced is a fixed-rate clk which has no reprogrammable aspects.
>>
>> The purpose of both types of clks is documented in drivers/clk/basic.c.
>>
> What I have seen is drivers/clk/clk-basic.c.

Will fix in v4.

>> +int clk_register_gate(struct device *dev, const char *name, unsigned long flags,
>> +             struct clk *fixed_parent, void __iomem *reg, u8 bit_idx,
>> +             int set_to_enable)
>> +{
>> +     struct clk_hw_gate *gclk;
>> +     struct clk *clk;
>> +
>> +     gclk = kmalloc(sizeof(struct clk_hw_gate), GFP_KERNEL);
>> +
>> +     if (!gclk) {
>> +             pr_err("%s: could not allocate gated clk\n", __func__);
>> +             return -ENOMEM;
>> +     }
>> +
>> +     clk = &gclk->clk;
>> +
>> +     /* struct clk_hw_gate assignments */
>> +     gclk->fixed_parent = fixed_parent;
>> +     gclk->reg = reg;
>> +     gclk->bit_idx = bit_idx;
>> +
>> +     /* struct clk assignments */
>> +     clk->name = name;
>> +     clk->flags = flags;
>> +
>> +     if (set_to_enable)
>> +             clk->ops = &clk_hw_gate_set_enable_ops;
>> +     else
>> +             clk->ops = &clk_hw_gate_set_disable_ops;
>> +
>> +     clk_init(NULL, clk);
>> +
>> +     return 0;
>
> The device tree support needs to get this 'struct clk *', so we may
> want to have all these registering functions return the 'clk'.

Thanks for the input. Truthfully I'm very DT-ignorant so I'm happy to
reshape any APIs for that topic. Hope to fix that soon.

Thanks for reviewing,
Mike
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