stm class: dummy_stm: Add dummy driver for testing stm class
This is a simple module that pretends to be an stm device and discards
all the data that comes in. Useful for testing stm class and its users.
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hwtracing/stm/Kconfig b/drivers/hwtracing/stm/Kconfig
index e101cb4..49c0984 100644
--- a/drivers/hwtracing/stm/Kconfig
+++ b/drivers/hwtracing/stm/Kconfig
@@ -6,3 +6,11 @@
Examples of such devices are Intel(R) Trace Hub and Coresight STM.
Say Y here to enable System Trace Module device support.
+
+config STM_DUMMY
+ tristate "Dummy STM driver"
+ help
+ This is a simple dummy device that pretends to be an stm device
+ and discards your data. Use for stm class testing.
+
+ If you don't know what this is, say N.
diff --git a/drivers/hwtracing/stm/Makefile b/drivers/hwtracing/stm/Makefile
index adec701..1b2725f 100644
--- a/drivers/hwtracing/stm/Makefile
+++ b/drivers/hwtracing/stm/Makefile
@@ -1,3 +1,5 @@
obj-$(CONFIG_STM) += stm_core.o
stm_core-y := core.o policy.o
+
+obj-$(CONFIG_STM_DUMMY) += dummy_stm.o
diff --git a/drivers/hwtracing/stm/dummy_stm.c b/drivers/hwtracing/stm/dummy_stm.c
new file mode 100644
index 0000000..3709bef
--- /dev/null
+++ b/drivers/hwtracing/stm/dummy_stm.c
@@ -0,0 +1,66 @@
+/*
+ * A dummy STM device for stm/stm_source class testing.
+ * Copyright (c) 2014, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * STM class implements generic infrastructure for System Trace Module devices
+ * as defined in MIPI STPv2 specification.
+ */
+
+#undef DEBUG
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/stm.h>
+
+static ssize_t
+dummy_stm_packet(struct stm_data *stm_data, unsigned int master,
+ unsigned int channel, unsigned int packet, unsigned int flags,
+ unsigned int size, const unsigned char *payload)
+{
+#ifdef DEBUG
+ u64 pl = 0;
+
+ if (payload)
+ pl = *(u64 *)payload;
+
+ if (size < 8)
+ pl &= (1ull << (size * 8)) - 1;
+ trace_printk("[%u:%u] [pkt: %x/%x] (%llx)\n", master, channel,
+ packet, size, pl);
+#endif
+ return size;
+}
+
+static struct stm_data dummy_stm = {
+ .name = "dummy_stm",
+ .sw_start = 0x0000,
+ .sw_end = 0xffff,
+ .sw_nchannels = 0xffff,
+ .packet = dummy_stm_packet,
+};
+
+static int dummy_stm_init(void)
+{
+ return stm_register_device(NULL, &dummy_stm, THIS_MODULE);
+}
+
+static void dummy_stm_exit(void)
+{
+ stm_unregister_device(&dummy_stm);
+}
+
+module_init(dummy_stm_init);
+module_exit(dummy_stm_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("dummy_stm device");
+MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");