[PATCH 3/3] cpufreq: Add a generic cpufreq-cpu0 driver
From: Shawn Guo <hidden>
Date: 2012-07-30 08:17:53
Also in:
linux-devicetree
On Fri, Jul 27, 2012 at 02:33:35PM +0800, Richard Zhao wrote:
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+Generic cpufreq driver for CPU0It's going to have generic name if it will become more generic.
I'm not in the position to say that it will become even more generic.
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+- voltage-tolerance: Specify the CPU voltage tolerance in percentage.Why do we have the same tolerance for all points?
Because I haven't seen any case that needs different tolerance for different operating points.
I think you can either remove tolerance or add it to opps.
I'm not going to remove it, because I have seen potential cpufreq-cpu0 candidates, e.g. omap-cpufreq, need it. It's also improper to encode it in operating-points, since OPP library does not have it.
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+ ret = clk_set_rate(cpu_clk, freqs.new * 1000);Check return value and fall back to previous point if it needs?
Right, the voltage should be reverted back if clk_set_rate fails.
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+ cpu_dev->of_node = np;hmm.. sys dev can not set of_node when populate it?
Since the sys dev is not populated from device tree, the of_node is not set, and we have to do it here on our own.
And why not do it in module init?
What's the advantage of doing it in module init over here?
static u32 max_freq = UINT_MAX / 1000; /* kHz */ module_param(max_freq, uint, 0); MODULE_PARM_DESC(max_freq, "max cpu frequency in unit of kHz"); It's for debug. Make sense?
It does not look so useful to me, as it never came to me when I was debugging the driver. -- Regards, Shawn