diff options
Diffstat (limited to 'arch/ia64/kernel/cyclone.c')
-rw-r--r-- | arch/ia64/kernel/cyclone.c | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/arch/ia64/kernel/cyclone.c b/arch/ia64/kernel/cyclone.c new file mode 100644 index 0000000000..258d7b70c0 --- /dev/null +++ b/arch/ia64/kernel/cyclone.c @@ -0,0 +1,125 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/module.h> +#include <linux/smp.h> +#include <linux/time.h> +#include <linux/errno.h> +#include <linux/timex.h> +#include <linux/clocksource.h> +#include <linux/io.h> + +/* IBM Summit (EXA) Cyclone counter code*/ +#define CYCLONE_CBAR_ADDR 0xFEB00CD0 +#define CYCLONE_PMCC_OFFSET 0x51A0 +#define CYCLONE_MPMC_OFFSET 0x51D0 +#define CYCLONE_MPCS_OFFSET 0x51A8 +#define CYCLONE_TIMER_FREQ 100000000 + +int use_cyclone; +void __init cyclone_setup(void) +{ + use_cyclone = 1; +} + +static void __iomem *cyclone_mc; + +static u64 read_cyclone(struct clocksource *cs) +{ + return (u64)readq((void __iomem *)cyclone_mc); +} + +static struct clocksource clocksource_cyclone = { + .name = "cyclone", + .rating = 300, + .read = read_cyclone, + .mask = (1LL << 40) - 1, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +int __init init_cyclone_clock(void) +{ + u64 __iomem *reg; + u64 base; /* saved cyclone base address */ + u64 offset; /* offset from pageaddr to cyclone_timer register */ + int i; + u32 __iomem *cyclone_timer; /* Cyclone MPMC0 register */ + + if (!use_cyclone) + return 0; + + printk(KERN_INFO "Summit chipset: Starting Cyclone Counter.\n"); + + /* find base address */ + offset = (CYCLONE_CBAR_ADDR); + reg = ioremap(offset, sizeof(u64)); + if(!reg){ + printk(KERN_ERR "Summit chipset: Could not find valid CBAR" + " register.\n"); + use_cyclone = 0; + return -ENODEV; + } + base = readq(reg); + iounmap(reg); + if(!base){ + printk(KERN_ERR "Summit chipset: Could not find valid CBAR" + " value.\n"); + use_cyclone = 0; + return -ENODEV; + } + + /* setup PMCC */ + offset = (base + CYCLONE_PMCC_OFFSET); + reg = ioremap(offset, sizeof(u64)); + if(!reg){ + printk(KERN_ERR "Summit chipset: Could not find valid PMCC" + " register.\n"); + use_cyclone = 0; + return -ENODEV; + } + writel(0x00000001,reg); + iounmap(reg); + + /* setup MPCS */ + offset = (base + CYCLONE_MPCS_OFFSET); + reg = ioremap(offset, sizeof(u64)); + if(!reg){ + printk(KERN_ERR "Summit chipset: Could not find valid MPCS" + " register.\n"); + use_cyclone = 0; + return -ENODEV; + } + writel(0x00000001,reg); + iounmap(reg); + + /* map in cyclone_timer */ + offset = (base + CYCLONE_MPMC_OFFSET); + cyclone_timer = ioremap(offset, sizeof(u32)); + if(!cyclone_timer){ + printk(KERN_ERR "Summit chipset: Could not find valid MPMC" + " register.\n"); + use_cyclone = 0; + return -ENODEV; + } + + /*quick test to make sure its ticking*/ + for(i=0; i<3; i++){ + u32 old = readl(cyclone_timer); + int stall = 100; + while(stall--) barrier(); + if(readl(cyclone_timer) == old){ + printk(KERN_ERR "Summit chipset: Counter not counting!" + " DISABLED\n"); + iounmap(cyclone_timer); + cyclone_timer = NULL; + use_cyclone = 0; + return -ENODEV; + } + } + /* initialize last tick */ + cyclone_mc = cyclone_timer; + clocksource_cyclone.archdata.fsys_mmio = cyclone_timer; + clocksource_register_hz(&clocksource_cyclone, CYCLONE_TIMER_FREQ); + + return 0; +} + +__initcall(init_cyclone_clock); |