On 26 May 2014 16:15, Lucas Stach <l.stach@xxxxxxxxxxxxxx> wrote: > This driver handles the i.MX5 specific clock reparenting to be able to > reprogramm the PLL. cpufreq-cpu0 can only change a postdivider of the > PLL, which means we can't reach the exact OPP frequencies and can not > profit from the additional power savings of a slower running PLL. > > Also without reprogramming the PLL we could possibly not scale to the > highest OPPs if the bootloader left the PLL at a slower rate. This is > the case for many i.MX53 boards, as the CPU regulator normally does > start up with the voltage required for 800MHz operation. If the > bootloader decides to not touch the regulator and set the PLL to 800MHz > the 1GHz and 1.2GHz operating points won't be useable. Almost all users of cpufreq-cpu0 has such situations and they have written a clock-driver for "cpu clock" to get this fixed. And they handle all this PLL stuff in clk_set_rate() for this new clock.. I still couldn't find anything so special here that can't be fixed this way. There is no point adding and maintaining a cpufreq driver if we can use cpufreq-cpu0. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
