diff --git a/arch/arm/mach-shmobile/setup-rcar-gen2.c b/arch/arm/mach-shmobile/setup-rcar-gen2.c index 1c6fd11c2f82..ea092d5dd475 100644 --- a/arch/arm/mach-shmobile/setup-rcar-gen2.c +++ b/arch/arm/mach-shmobile/setup-rcar-gen2.c @@ -46,6 +46,26 @@ u32 rcar_gen2_read_mode_pins(void) return mode; } +static unsigned int __init get_extal_freq(void) +{ + struct device_node *cpg, *extal; + u32 freq = 20000000; + + cpg = of_find_compatible_node(NULL, NULL, + "renesas,rcar-gen2-cpg-clocks"); + if (!cpg) + return freq; + + extal = of_parse_phandle(cpg, "clocks", 0); + of_node_put(cpg); + if (!extal) + return freq; + + of_property_read_u32(extal, "clock-frequency", &freq); + of_node_put(extal); + return freq; +} + #define CNTCR 0 #define CNTFID0 0x20 @@ -54,7 +74,6 @@ void __init rcar_gen2_timer_init(void) u32 mode = rcar_gen2_read_mode_pins(); #ifdef CONFIG_ARM_ARCH_TIMER void __iomem *base; - int extal_mhz = 0; u32 freq; if (of_machine_is_compatible("renesas,r8a7794")) { @@ -82,26 +101,9 @@ void __init rcar_gen2_timer_init(void) * with the counter disabled. Moreover, it may also report * a potentially incorrect fixed 13 MHz frequency. To be * correct these registers need to be updated to use the - * frequency EXTAL / 2 which can be determined by the MD pins. + * frequency EXTAL / 2. */ - - switch (mode & (MD(14) | MD(13))) { - case 0: - extal_mhz = 15; - break; - case MD(13): - extal_mhz = 20; - break; - case MD(14): - extal_mhz = 26; - break; - case MD(13) | MD(14): - extal_mhz = 30; - break; - } - - /* The arch timer frequency equals EXTAL / 2 */ - freq = extal_mhz * (1000000 / 2); + freq = get_extal_freq() / 2; } /* Remap "armgcnt address map" space */