diff options
Diffstat (limited to 'arch/arm/mach-shmobile/timer.c')
| -rw-r--r-- | arch/arm/mach-shmobile/timer.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/timer.c b/arch/arm/mach-shmobile/timer.c index 62d7052d6f2..68bc0b82226 100644 --- a/arch/arm/mach-shmobile/timer.c +++ b/arch/arm/mach-shmobile/timer.c @@ -21,6 +21,24 @@ #include <linux/platform_device.h> #include <linux/clocksource.h> #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) @@ -39,6 +57,33 @@ void __init shmobile_setup_delay(unsigned int max_cpu_core_mhz, preset_lpj = max_cpu_core_mhz * value; } +void __init shmobile_init_delay(void) +{ + struct device_node *np, *parent; + u32 max_freq, freq; + + max_freq = 0; + + parent = of_find_node_by_path("/cpus"); + if (parent) { + for_each_child_of_node(parent, np) { + if (!of_property_read_u32(np, "clock-frequency", &freq)) + max_freq = max(max_freq, freq); + } + of_node_put(parent); + } + + if (max_freq) { + if (of_find_compatible_node(NULL, NULL, "arm,cortex-a8")) + shmobile_setup_delay_hz(max_freq, 1, 3); + else if (of_find_compatible_node(NULL, NULL, "arm,cortex-a9")) + 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_hz(max_freq, 2, 4); + } +} + static void __init shmobile_late_time_init(void) { /* |