ARM: shmobile: Set clock frequency in HZ from OF nodes
shmobile_init_delay() looks for OF "clock-frequency" to determine
the delay which is set by calling shmobile_setup_delay().
Unfortunately this seems to be incorrect in detail as
"clock-frequency" node values are in HZ whereas the frequency
argument to shmobile_setup_delay() is in MHz.
Provide a variant of shmobile_setup_delay() that accepts HZ to
correct this problem.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
diff --git a/arch/arm/mach-shmobile/timer.c b/arch/arm/mach-shmobile/timer.c
index ccecde9..68bc0b8 100644
--- a/arch/arm/mach-shmobile/timer.c
+++ b/arch/arm/mach-shmobile/timer.c
@@ -23,6 +23,23 @@
#include <linux/delay.h>
#include <linux/of_address.h>
+void __init shmobile_setup_delay_hz(unsigned int max_cpu_core_hz,
+ unsigned int mult, unsigned int div)
+{
+ /* calculate a worst-case loops-per-jiffy value
+ * based on maximum cpu core hz setting and the
+ * __delay() implementation in arch/arm/lib/delay.S
+ *
+ * this will result in a longer delay than expected
+ * when the cpu core runs on lower frequencies.
+ */
+
+ unsigned int value = HZ * div / mult;
+
+ if (!preset_lpj)
+ preset_lpj = max_cpu_core_hz / value;
+}
+
void __init shmobile_setup_delay(unsigned int max_cpu_core_mhz,
unsigned int mult, unsigned int div)
{
@@ -58,12 +75,12 @@
if (max_freq) {
if (of_find_compatible_node(NULL, NULL, "arm,cortex-a8"))
- shmobile_setup_delay(max_freq, 1, 3);
+ shmobile_setup_delay_hz(max_freq, 1, 3);
else if (of_find_compatible_node(NULL, NULL, "arm,cortex-a9"))
- shmobile_setup_delay(max_freq, 1, 3);
+ shmobile_setup_delay_hz(max_freq, 1, 3);
else if (of_find_compatible_node(NULL, NULL, "arm,cortex-a15"))
if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
- shmobile_setup_delay(max_freq, 2, 4);
+ shmobile_setup_delay_hz(max_freq, 2, 4);
}
}
