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,
I don't think you should add this file.
1. big Little is not exynos specific
2. /dev is not for the purpose of your patch
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 ?
Frankly speaking, it would make sense to add traces in mcpm.c (if they
aren't already there - did not check).
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);
--
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