HID: wiimote: Allow direct DRM debug access

Keep track of current drm and add new debugfs file which reads or writes the
current DRM.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

3 files changed, 107 insertions, 4 deletions

diff --git a/drivers/hid/hid-wiimote-core.c b/drivers/hid/hid-wiimote-core.c
index 2fd2f0337b8d..745667e8b61b 100644
--- a/drivers/hid/hid-wiimote-core.c
+++ b/drivers/hid/hid-wiimote-core.c
@@ -238,6 +238,7 @@ void wiiproto_req_drm(struct wiimote_data *wdata, __u8 drm)
         cmd[1] = 0;
         cmd[2] = drm;
 
+        wdata->state.drm = drm;
         wiiproto_keep_rumble(wdata, &cmd[1]);
         wiimote_queue(wdata, cmd, sizeof(cmd));
 }
@@ -1141,6 +1142,7 @@ static struct wiimote_data *wiimote_create(struct hid_device *hdev)
         spin_lock_init(&wdata->state.lock);
         init_completion(&wdata->state.ready);
         mutex_init(&wdata->state.sync);
+        wdata->state.drm = WIIPROTO_REQ_DRM_K;
 
         return wdata;
 
diff --git a/drivers/hid/hid-wiimote-debug.c b/drivers/hid/hid-wiimote-debug.c
index f81243c86790..17dabc1f339e 100644
--- a/drivers/hid/hid-wiimote-debug.c
+++ b/drivers/hid/hid-wiimote-debug.c
@@ -12,6 +12,7 @@
 
 #include <linux/debugfs.h>
 #include <linux/module.h>
+#include <linux/seq_file.h>
 #include <linux/spinlock.h>
 #include <linux/uaccess.h>
 #include "hid-wiimote.h"
@@ -19,6 +20,7 @@
 struct wiimote_debug {
         struct wiimote_data *wdata;
         struct dentry *eeprom;
+        struct dentry *drm;
 };
 
 static int wiidebug_eeprom_open(struct inode *i, struct file *f)
@@ -86,10 +88,97 @@ static const struct file_operations wiidebug_eeprom_fops = {
         .llseek = generic_file_llseek,
 };
 
+static const char *wiidebug_drmmap[] = {
+        [WIIPROTO_REQ_NULL] = "NULL",
+        [WIIPROTO_REQ_DRM_K] = "K",
+        [WIIPROTO_REQ_DRM_KA] = "KA",
+        [WIIPROTO_REQ_DRM_KE] = "KE",
+        [WIIPROTO_REQ_DRM_KAI] = "KAI",
+        [WIIPROTO_REQ_DRM_KEE] = "KEE",
+        [WIIPROTO_REQ_DRM_KAE] = "KAE",
+        [WIIPROTO_REQ_DRM_KIE] = "KIE",
+        [WIIPROTO_REQ_DRM_KAIE] = "KAIE",
+        [WIIPROTO_REQ_DRM_E] = "E",
+        [WIIPROTO_REQ_DRM_SKAI1] = "SKAI1",
+        [WIIPROTO_REQ_DRM_SKAI2] = "SKAI2",
+        [WIIPROTO_REQ_MAX] = NULL
+};
+
+static int wiidebug_drm_show(struct seq_file *f, void *p)
+{
+        struct wiimote_debug *dbg = f->private;
+        const char *str = NULL;
+        unsigned long flags;
+        __u8 drm;
+
+        spin_lock_irqsave(&dbg->wdata->state.lock, flags);
+        drm = dbg->wdata->state.drm;
+        spin_unlock_irqrestore(&dbg->wdata->state.lock, flags);
+
+        if (drm < WIIPROTO_REQ_MAX)
+                str = wiidebug_drmmap[drm];
+        if (!str)
+                str = "unknown";
+
+        seq_printf(f, "%s\n", str);
+
+        return 0;
+}
+
+static int wiidebug_drm_open(struct inode *i, struct file *f)
+{
+        return single_open(f, wiidebug_drm_show, i->i_private);
+}
+
+static ssize_t wiidebug_drm_write(struct file *f, const char __user *u,
+                                                        size_t s, loff_t *off)
+{
+        struct wiimote_debug *dbg = f->private_data;
+        unsigned long flags;
+        char buf[16];
+        ssize_t len;
+        int i;
+
+        if (s == 0)
+                return -EINVAL;
+
+        len = min((size_t) 15, s);
+        if (copy_from_user(buf, u, len))
+                return -EFAULT;
+
+        buf[15] = 0;
+
+        for (i = 0; i < WIIPROTO_REQ_MAX; ++i) {
+                if (!wiidebug_drmmap[i])
+                        continue;
+                if (!strcasecmp(buf, wiidebug_drmmap[i]))
+                        break;
+        }
+
+        if (i == WIIPROTO_REQ_MAX)
+                i = simple_strtoul(buf, NULL, 10);
+
+        spin_lock_irqsave(&dbg->wdata->state.lock, flags);
+        wiiproto_req_drm(dbg->wdata, (__u8) i);
+        spin_unlock_irqrestore(&dbg->wdata->state.lock, flags);
+
+        return len;
+}
+
+static const struct file_operations wiidebug_drm_fops = {
+        .owner = THIS_MODULE,
+        .open = wiidebug_drm_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .write = wiidebug_drm_write,
+        .release = single_release,
+};
+
 int wiidebug_init(struct wiimote_data *wdata)
 {
         struct wiimote_debug *dbg;
         unsigned long flags;
+        int ret = -ENOMEM;
 
         dbg = kzalloc(sizeof(*dbg), GFP_KERNEL);
         if (!dbg)
@@ -99,16 +188,25 @@ int wiidebug_init(struct wiimote_data *wdata)
 
         dbg->eeprom = debugfs_create_file("eeprom", S_IRUSR,
                 dbg->wdata->hdev->debug_dir, dbg, &wiidebug_eeprom_fops);
-        if (!dbg->eeprom) {
-                kfree(dbg);
-                return -ENOMEM;
-        }
+        if (!dbg->eeprom)
+                goto err;
+
+        dbg->drm = debugfs_create_file("drm", S_IRUSR,
+                        dbg->wdata->hdev->debug_dir, dbg, &wiidebug_drm_fops);
+        if (!dbg->drm)
+                goto err_drm;
 
         spin_lock_irqsave(&wdata->state.lock, flags);
         wdata->debug = dbg;
         spin_unlock_irqrestore(&wdata->state.lock, flags);
 
         return 0;
+
+err_drm:
+        debugfs_remove(dbg->eeprom);
+err:
+        kfree(dbg);
+        return ret;
 }
 
 void wiidebug_deinit(struct wiimote_data *wdata)
@@ -123,6 +221,7 @@ void wiidebug_deinit(struct wiimote_data *wdata)
         wdata->debug = NULL;
         spin_unlock_irqrestore(&wdata->state.lock, flags);
 
+        debugfs_remove(dbg->drm);
         debugfs_remove(dbg->eeprom);
         kfree(dbg);
 }
diff --git a/drivers/hid/hid-wiimote.h b/drivers/hid/hid-wiimote.h
index 7b6765797f81..c81dbeb086c5 100644
--- a/drivers/hid/hid-wiimote.h
+++ b/drivers/hid/hid-wiimote.h
@@ -52,6 +52,7 @@ struct wiimote_state {
         spinlock_t lock;
         __u8 flags;
         __u8 accel_split[2];
+        __u8 drm;
 
         /* synchronous cmd requests */
         struct mutex sync;
@@ -109,6 +110,7 @@ enum wiiproto_reqs {
         WIIPROTO_REQ_DRM_E = 0x3d,
         WIIPROTO_REQ_DRM_SKAI1 = 0x3e,
         WIIPROTO_REQ_DRM_SKAI2 = 0x3f,
+        WIIPROTO_REQ_MAX
 };
 
 #define dev_to_wii(pdev) hid_get_drvdata(container_of(pdev, struct hid_device, \