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 (file)
--- a/drivers/hwtracing/stm/Kconfig
+++ b/drivers/hwtracing/stm/Kconfig
@@ -6,3 +6,11 @@ config STM
          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 (file)
--- 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 (file)
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>");