On Mon, Apr 28, 2014 at 4:55 PM, Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> wrote: > On 04/26/2014 06:05 PM, Abhilash Kesavan wrote: >> >> Add a user interface to check the core and cluster status on >> Exynos5420. This can be utilized while debugging mcpm issues. >> cat /dev/bL_status will show the current power status of all >> the 8 cores along with the cluster. >> >> Signed-off-by: Thomas Abraham <thomas.ab@xxxxxxxxxxx> >> Signed-off-by: Inderpal Singh <inderpal.s@xxxxxxxxxxx> >> Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx> >> Signed-off-by: Abhilash Kesavan <a.kesavan@xxxxxxxxxxx> >> --- > > > Hi Abhilash, Hi Daniel, > > I don't think you should add this file. > > 1. big Little is not exynos specific But the core control/status bits that I am accessing are exynos specific and currently it is being enabled only on 5420. > 2. /dev is not for the purpose of your patch OK. > > So I would recommend: > > 1. create a generic infra-structure for all the big.Little > 2. and/or use debugfs > > Furthermore, how is it usable ? Will you read the file every 2ms to check > the cluster status, knowing it will be woken up by the read operation ? This was just a quick way to check the power status of the cores/cluster during cpufreq controlled core switching. Maybe not as useful in case of cpuidle. > > Frankly speaking, it would make sense to add traces in mcpm.c (if they > aren't already there - did not check). Fair enough, the core bL_switcher code does have code for trace events. I can check more on that. Regards, Abhilash > > >> arch/arm/mach-exynos/mcpm-exynos.c | 64 >> ++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 64 insertions(+) >> >> diff --git a/arch/arm/mach-exynos/mcpm-exynos.c >> b/arch/arm/mach-exynos/mcpm-exynos.c >> index f9977bf..83428b0 100644 >> --- a/arch/arm/mach-exynos/mcpm-exynos.c >> +++ b/arch/arm/mach-exynos/mcpm-exynos.c >> @@ -269,6 +269,53 @@ static void __init exynos_mcpm_usage_count_init(void) >> cpu_use_count[cpu][cluster] = 1; >> } >> >> +static size_t bL_check_status(char *info) >> +{ >> + size_t len = 0; >> + int i; >> + >> + len += sprintf(&info[len], "\t0 1 2 3 L2\n"); >> + len += sprintf(&info[len], "[A15] "); >> + for (i = 0; i < 4; i++) { >> + len += sprintf(&info[len], "%d ", >> + (readl(EXYNOS_ARM_CORE_STATUS(i)) & 0x3) == 3 ? 1 >> : 0); >> + } >> + len += sprintf(&info[len], "%d\n", >> + (readl(EXYNOS_COMMON_STATUS(0)) & 0x3) == 3 ? 1 : >> 0); >> + >> + len += sprintf(&info[len], "[A7] "); >> + for (i = 4; i < 8; i++) >> + len += sprintf(&info[len], "%d ", >> + (readl(EXYNOS_ARM_CORE_STATUS(i)) & 0x3) == 3 ? 1 >> : 0); >> + len += sprintf(&info[len], "%d\n\n", >> + (readl(EXYNOS_COMMON_STATUS(1)) & 0x3) == 3 ? 1 : >> 0); >> + >> + return len; >> +} >> + >> +static ssize_t bL_status_read(struct file *file, char __user *buf, >> + size_t len, loff_t *pos) >> +{ >> + size_t count = 0; >> + char info[100]; >> + >> + count = bL_check_status(info); >> + if (count < 0) >> + return -EINVAL; >> + >> + return simple_read_from_buffer(buf, len, pos, info, count); >> +} >> + >> +static const struct file_operations bL_status_fops = { >> + .read = bL_status_read, >> +}; >> + >> +static struct miscdevice bL_status_device = { >> + MISC_DYNAMIC_MINOR, >> + "bL_status", >> + &bL_status_fops >> +}; >> + >> /* >> * Enable cluster-level coherency, in preparation for turning on the >> MMU. >> */ >> @@ -319,3 +366,20 @@ static int __init exynos_mcpm_init(void) >> } >> >> early_initcall(exynos_mcpm_init); >> + >> +static int __init exynos_bl_status_init(void) >> +{ >> + int ret; >> + >> + if (!soc_is_exynos5420()) >> + return -ENODEV; >> + >> + ret = misc_register(&bL_status_device); >> + if (ret) { >> + pr_info("bl_status not available\n"); >> + return ret; >> + } >> + return 0; >> +} >> + >> +late_initcall(exynos_bl_status_init); >> > > > -- > <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs > > Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | > <http://twitter.com/#!/linaroorg> Twitter | > <http://www.linaro.org/linaro-blog/> Blog > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html