On Mon, Jun 30, 2014 at 12:39:26PM +0200, Vincent Guittot wrote: > On 30 June 2014 12:29, Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> wrote: > > On Mon, Jun 30, 2014 at 12:12:22PM +0200, Maxime Ripard wrote: > >> The Cortex-A7 and Cortex-A15 based SoCs need a clock-frequency property in the > >> topology code. > >> > >> Allow to use a clock to provide the same information. > >> > >> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> > > > > This looks fine to me, but I don't know this code. Maybe Vincent Guittot > > should be on the To: list (added)? > > Thanks Ah, sorry for that. > > > > >> --- > >> arch/arm/kernel/topology.c | 25 ++++++++++++++++++------- > >> 1 file changed, 18 insertions(+), 7 deletions(-) > >> > >> diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c > >> index 9d853189028b..268443d88094 100644 > >> --- a/arch/arm/kernel/topology.c > >> +++ b/arch/arm/kernel/topology.c > >> @@ -11,6 +11,7 @@ > >> * for more details. > >> */ > >> > >> +#include <linux/clk.h> > >> #include <linux/cpu.h> > >> #include <linux/cpumask.h> > >> #include <linux/export.h> > >> @@ -100,8 +101,8 @@ static void __init parse_dt_topology(void) > >> GFP_NOWAIT); > >> > >> for_each_possible_cpu(cpu) { > >> - const u32 *rate; > >> - int len; > >> + struct clk *clk; > >> + u32 rate = 0; > >> > >> /* too early to use cpu->of_node */ > >> cn = of_get_cpu_node(cpu, NULL); > >> @@ -117,14 +118,24 @@ static void __init parse_dt_topology(void) > >> if (cpu_eff->compatible == NULL) > >> continue; > >> > >> - rate = of_get_property(cn, "clock-frequency", &len); > >> - if (!rate || len != 4) { > >> - pr_err("%s missing clock-frequency property\n", > >> - cn->full_name); > >> + clk = of_clk_get(cn, 0); > >> + if (!IS_ERR(clk)) > >> + rate = clk_get_rate(clk); > > We need the max frequency as it will be used to weight the different > CPUs capacity. How do you ensure that the current clock rate is the > max one ? Hmm, the clock-frequency attribute in the ePAPR is defined at the current CPU frequency, not the max one. Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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