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authorNicolas Pitre <nicolas.pitre@linaro.org>2012-04-12 03:04:28 -0400
committerNicolas Pitre <nicolas.pitre@linaro.org>2013-05-13 19:05:27 -0400
commit2be12549c900303c418fcbb7044979e190fd4e7e (patch)
tree7386c714a03976d31f2c8f8654a6fbd879e7310d
parentde2773b359751f6abf40b1112b07c1d1da26e786 (diff)
downloadlinux-linaro-stable-v3.9/iks.tar.gz
ARM: bL_switcher: add a simple /dev user interface for debugging purposesv3.9/iks
Only the basic to aid debugging. Usage: echo <cpuid>,<clusterid> > /dev/b.L_switcher where <cpuid> is between 0 and 3, and <clusterid> is 0 for the A15 cluster and 1 for the A7 cluster. Signed-off-by: nicolas Pitre <nico@linaro.org>
-rw-r--r--arch/arm/Kconfig8
-rw-r--r--arch/arm/common/Makefile1
-rw-r--r--arch/arm/common/bL_switcher_dummy_if.c71
3 files changed, 80 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index c5fd434..74538c6 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1624,6 +1624,14 @@ config BL_SWITCHER
transparently handle transition between a cluster of A15's
and a cluster of A7's in a big.LITTLE system.
+config BL_SWITCHER_DUMMY_IF
+ tristate "Simple big.LITTLE switcher user interface"
+ depends on BL_SWITCHER && DEBUG_KERNEL
+ help
+ This is a simple and dummy char dev interface to control
+ the big.LITTLE switcher core code. It is meant for
+ debugging purposes only.
+
choice
prompt "Memory split"
default VMSPLIT_3G
diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index ed4c489..d35f28a 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -15,3 +15,4 @@ obj-$(CONFIG_MCPM) += mcpm_head.o mcpm_entry.o mcpm_platsmp.o vlock.o
AFLAGS_mcpm_head.o := -march=armv7-a
AFLAGS_vlock.o := -march=armv7-a
obj-$(CONFIG_BL_SWITCHER) += bL_switcher.o
+obj-$(CONFIG_BL_SWITCHER_DUMMY_IF) += bL_switcher_dummy_if.o
diff --git a/arch/arm/common/bL_switcher_dummy_if.c b/arch/arm/common/bL_switcher_dummy_if.c
new file mode 100644
index 0000000..5e2dd19
--- /dev/null
+++ b/arch/arm/common/bL_switcher_dummy_if.c
@@ -0,0 +1,71 @@
+/*
+ * arch/arm/common/bL_switcher_dummy_if.c -- b.L switcher dummy interface
+ *
+ * Created by: Nicolas Pitre, November 2012
+ * Copyright: (C) 2012 Linaro Limited
+ *
+ * Dummy interface to user space for debugging purpose only.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <asm/uaccess.h>
+#include <asm/bL_switcher.h>
+
+static ssize_t bL_switcher_write(struct file *file, const char __user *buf,
+ size_t len, loff_t *pos)
+{
+ unsigned char val[3];
+ unsigned int cpu, cluster;
+ int ret;
+
+ pr_debug("%s\n", __func__);
+
+ if (len < 3)
+ return -EINVAL;
+
+ if (copy_from_user(val, buf, 3))
+ return -EFAULT;
+
+ /* format: <cpu#>,<cluster#> */
+ if (val[0] < '0' || val[0] > '4' ||
+ val[1] != ',' ||
+ val[2] < '0' || val[2] > '1')
+ return -EINVAL;
+
+ cpu = val[0] - '0';
+ cluster = val[2] - '0';
+ ret = bL_switch_request(cpu, cluster);
+
+ return ret ? : len;
+}
+
+static const struct file_operations bL_switcher_fops = {
+ .write = bL_switcher_write,
+ .owner = THIS_MODULE,
+};
+
+static struct miscdevice bL_switcher_device = {
+ MISC_DYNAMIC_MINOR,
+ "b.L_switcher",
+ &bL_switcher_fops
+};
+
+static int __init bL_switcher_dummy_if_init(void)
+{
+ return misc_register(&bL_switcher_device);
+}
+
+static void __exit bL_switcher_dummy_if_exit(void)
+{
+ misc_deregister(&bL_switcher_device);
+}
+
+module_init(bL_switcher_dummy_if_init);
+module_exit(bL_switcher_dummy_if_exit);