1 files changed, 126 insertions, 0 deletions

diff --git a/Documentation/firmware_class/firmware_sample_driver.c b/Documentation/firmware_class/firmware_sample_driver.c
new file mode 100644
index 000000000000..e1c56a7e6583
--- /dev/null
+++ b/Documentation/firmware_class/firmware_sample_driver.c
@@ -0,0 +1,126 @@
+/*
+ * firmware_sample_driver.c -
+ *
+ * Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
+ *
+ * Sample code on how to use request_firmware() from drivers.
+ *
+ * Note that register_firmware() is currently useless.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/device.h>
+
+#include "linux/firmware.h"
+
+#define WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
+#ifdef WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
+char __init inkernel_firmware[] = "let's say that this is firmware\n";
+#endif
+
+static struct device ghost_device = {
+        .name      = "Ghost Device",
+        .bus_id    = "ghost0",
+};
+
+
+static void sample_firmware_load(char *firmware, int size)
+{
+        u8 buf[size+1];
+        memcpy(buf, firmware, size);
+        buf[size] = '\0';
+        printk("firmware_sample_driver: firmware: %s\n", buf);
+}
+
+static void sample_probe_default(void)
+{
+        /* uses the default method to get the firmware */
+        const struct firmware *fw_entry;
+        printk("firmware_sample_driver: a ghost device got inserted :)\n");
+
+        if(request_firmware(&fw_entry, "sample_driver_fw", &ghost_device)!=0)
+        {
+                printk(KERN_ERR
+                       "firmware_sample_driver: Firmware not available\n");
+                return;
+        }
+        
+        sample_firmware_load(fw_entry->data, fw_entry->size);
+
+        release_firmware(fw_entry);
+
+        /* finish setting up the device */
+}
+static void sample_probe_specific(void)
+{
+        /* Uses some specific hotplug support to get the firmware from
+         * userspace  directly into the hardware, or via some sysfs file */
+
+        /* NOTE: This currently doesn't work */
+
+        printk("firmware_sample_driver: a ghost device got inserted :)\n");
+
+        if(request_firmware(NULL, "sample_driver_fw", &ghost_device)!=0)
+        {
+                printk(KERN_ERR
+                       "firmware_sample_driver: Firmware load failed\n");
+                return;
+        }
+        
+        /* request_firmware blocks until userspace finished, so at
+         * this point the firmware should be already in the device */
+
+        /* finish setting up the device */
+}
+static void sample_probe_async_cont(const struct firmware *fw, void *context)
+{
+        if(!fw){
+                printk(KERN_ERR
+                       "firmware_sample_driver: firmware load failed\n");
+                return;
+        }
+
+        printk("firmware_sample_driver: device pointer \"%s\"\n",
+               (char *)context);
+        sample_firmware_load(fw->data, fw->size);
+}
+static void sample_probe_async(void)
+{
+        /* Let's say that I can't sleep */
+        int error;
+        error = request_firmware_nowait (THIS_MODULE,
+                                         "sample_driver_fw", &ghost_device,
+                                         "my device pointer",
+                                         sample_probe_async_cont);
+        if(error){
+                printk(KERN_ERR 
+                       "firmware_sample_driver:"
+                       " request_firmware_nowait failed\n");
+        }
+}
+
+static int sample_init(void)
+{
+#ifdef WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE
+        register_firmware("sample_driver_fw", inkernel_firmware,
+                          sizeof(inkernel_firmware));
+#endif
+        device_initialize(&ghost_device);
+        /* since there is no real hardware insertion I just call the
+         * sample probe functions here */
+        sample_probe_specific();
+        sample_probe_default();
+        sample_probe_async();
+        return 0;
+}
+static void __exit sample_exit(void)
+{
+}
+
+module_init (sample_init);
+module_exit (sample_exit);
+
+MODULE_LICENSE("GPL");