On Mon, Jun 30, 2014 at 12:39:26PM +0200, Vincent Guittot wrote:
On 30 June 2014 12:29, Russell King - ARM Linux [off-list ref] wrote:
quoted
On Mon, Jun 30, 2014 at 12:12:22PM +0200, Maxime Ripard wrote:
quoted
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-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
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.
quoted
quoted
---
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
On 30 June 2014 14:49, Maxime Ripard [off-list ref] wrote:
On Mon, Jun 30, 2014 at 12:39:26PM +0200, Vincent Guittot wrote:
quoted
On 30 June 2014 12:29, Russell King - ARM Linux [off-list ref] wrote:
quoted
On Mon, Jun 30, 2014 at 12:12:22PM +0200, Maxime Ripard wrote:
quoted
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-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
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.
quoted
quoted
quoted
---
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.
What means current frequency in device tree when DVFS is involved ?
Vincent
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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