diff options
Diffstat (limited to 'arch/powerpc/platforms/85xx/common.c')
| -rw-r--r-- | arch/powerpc/platforms/85xx/common.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/85xx/common.c b/arch/powerpc/platforms/85xx/common.c index 1269a10..43025d0 100644 --- a/arch/powerpc/platforms/85xx/common.c +++ b/arch/powerpc/platforms/85xx/common.c @@ -7,10 +7,22 @@ */ #include <linux/of_platform.h> +#include <asm/time.h> + #include <sysdev/cpm2_pic.h> #include "mpc85xx.h" +#define MAX_BIT 64 + +#define ALTIVEC_COUNT_OFFSET 16 +#define ALTIVEC_IDLE_COUNT_MASK 0x003f0000 + +/* + * FIXME - We don't know the AltiVec application scenarios. + */ +#define ALTIVEC_IDLE_TIME 1000 /* 1ms */ + static struct of_device_id __initdata mpc85xx_common_ids[] = { { .type = "soc", }, { .compatible = "soc", }, @@ -82,3 +94,53 @@ void __init mpc85xx_cpm2_pic_init(void) irq_set_chained_handler(irq, cpm2_cascade); } #endif + +static unsigned int get_idle_ticks_bit(unsigned int us) +{ + unsigned int cycle; + + /* + * The time control by TB turn over bit, so we need + * to be divided by 2. + */ + cycle = (us / 2) * tb_ticks_per_usec; + + return ilog2(cycle) + 1; +} + +static void setup_altivec_idle(void *unused) +{ + u32 altivec_idle, pvr, bit; + + pvr = mfspr(SPRN_PVR); + + /* AltiVec idle feature only exists for E6500 */ + if (PVR_VER(pvr) != PVR_VER_E6500) + return; + + /* Fix erratum, e6500 rev1 not support altivec idle */ + if (PVR_REV(pvr) < 0x20) + return; + + /* Enable Altivec Idle */ + altivec_idle = mfspr(SPRN_PWRMGTCR0); + altivec_idle |= PWRMGTCR0_ALTIVEC_IDLE; + + /* Set Automatic AltiVec Idle Count */ + /* clear count */ + altivec_idle &= ~ALTIVEC_IDLE_COUNT_MASK; + + /* set count */ + bit = get_idle_ticks_bit(ALTIVEC_IDLE_TIME); + altivec_idle |= ((MAX_BIT - bit) << ALTIVEC_COUNT_OFFSET); + + mtspr(SPRN_PWRMGTCR0, altivec_idle); +} + +static int __init setup_idle_hw_governor(void) +{ + on_each_cpu(setup_altivec_idle, NULL, 1); + + return 0; +} +late_initcall(setup_idle_hw_governor); |