media: cec: add core error injection support

Add two new ops (error_inj_show and error_inj_parse_line) to support
error injection functionality for CEC adapters. If both are present,
then the core will add a new error-inj debugfs file that can be used
to see the current error injection commands and to set error injection
commands.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/cec/cec-core.c b/drivers/media/cec/cec-core.c
index e47ea22..ea3eccf 100644 (file)
--- a/drivers/media/cec/cec-core.c
+++ b/drivers/media/cec/cec-core.c
@@ -195,6 +195,55 @@ void cec_register_cec_notifier(struct cec_adapter *adap,
 EXPORT_SYMBOL_GPL(cec_register_cec_notifier);
 #endif
 
+#ifdef CONFIG_DEBUG_FS
+static ssize_t cec_error_inj_write(struct file *file,
+       const char __user *ubuf, size_t count, loff_t *ppos)
+{
+       struct seq_file *sf = file->private_data;
+       struct cec_adapter *adap = sf->private;
+       char *buf;
+       char *line;
+       char *p;
+
+       buf = memdup_user_nul(ubuf, min_t(size_t, PAGE_SIZE, count));
+       if (IS_ERR(buf))
+               return PTR_ERR(buf);
+       p = buf;
+       while (p && *p && count >= 0) {
+               p = skip_spaces(p);
+               line = strsep(&p, "\n");
+               if (!*line || *line == '#')
+                       continue;
+               if (!adap->ops->error_inj_parse_line(adap, line)) {
+                       count = -EINVAL;
+                       break;
+               }
+       }
+       kfree(buf);
+       return count;
+}
+
+static int cec_error_inj_show(struct seq_file *sf, void *unused)
+{
+       struct cec_adapter *adap = sf->private;
+
+       return adap->ops->error_inj_show(adap, sf);
+}
+
+static int cec_error_inj_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, cec_error_inj_show, inode->i_private);
+}
+
+static const struct file_operations cec_error_inj_fops = {
+       .open = cec_error_inj_open,
+       .write = cec_error_inj_write,
+       .read = seq_read,
+       .llseek = seq_lseek,
+       .release = single_release,
+};
+#endif
+
 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
                                         void *priv, const char *name, u32 caps,
                                         u8 available_las)
@@ -334,7 +383,16 @@ int cec_register_adapter(struct cec_adapter *adap,
                pr_warn("cec-%s: Failed to create status file\n", adap->name);
                debugfs_remove_recursive(adap->cec_dir);
                adap->cec_dir = NULL;
+               return 0;
        }
+       if (!adap->ops->error_inj_show || !adap->ops->error_inj_parse_line)
+               return 0;
+       adap->error_inj_file = debugfs_create_file("error-inj", 0644,
+                                                  adap->cec_dir, adap,
+                                                  &cec_error_inj_fops);
+       if (IS_ERR_OR_NULL(adap->error_inj_file))
+               pr_warn("cec-%s: Failed to create error-inj file\n",
+                       adap->name);
 #endif
        return 0;
 }

diff --git a/include/media/cec.h b/include/media/cec.h
index 9afba9b..41df048 100644 (file)
--- a/include/media/cec.h
+++ b/include/media/cec.h
@@ -117,6 +117,10 @@ struct cec_adap_ops {
        void (*adap_status)(struct cec_adapter *adap, struct seq_file *file);
        void (*adap_free)(struct cec_adapter *adap);
 
+       /* Error injection callbacks */
+       int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf);
+       bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line);
+
        /* High-level CEC message callback */
        int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
 };
@@ -189,6 +193,7 @@ struct cec_adapter {
 
        struct dentry *cec_dir;
        struct dentry *status_file;
+       struct dentry *error_inj_file;
 
        u16 phys_addrs[15];
        u32 sequence;