Re: [PATCH v3] of: Add videomode helper

On Fri, Sep 14, 2012 at 11:24 AM, Steffen Trumtrar
[off-list ref] wrote:

+/* FIXME */
+static u32 of_video_get_value(struct mode_property *prop)
+{
+       return (prop->min >= prop->typ) ? prop->min : prop->typ;
+}
+
+/* read property into new mode_property */
+static int of_video_parse_property(struct device_node *np, char *name,
+                               struct mode_property *result)
+{
+       struct property *prop;
+       int length;
+       int cells;
+       int ret;
+
+       prop = of_find_property(np, name, &length);
+       if (!prop)
+               return -EINVAL;
+
+       cells = length / sizeof(u32);
+
+       memset(result, 0, sizeof(*result));
+
+       ret = of_property_read_u32_array(np, name, &result->min, cells);
+       of_video_get_value(result);

What's the point of calling of_video_get_value() here?  It doesn't do anything.

+       return ret;
+}
+
+int videomode_to_display_mode(struct display *disp, struct drm_display_mode *dmode, int index)
+{
+       struct videomode *vm;
+
+        memset(dmode, 0, sizeof(*dmode));

Indentation problem.

+int of_get_video_mode(struct device_node *np, struct display *disp)
+{
+       struct device_node *display_np;
+       struct device_node *mode_np;
+       struct device_node *modes_np;
+       char *default_mode;
+
+       int ret = 0;
+
+       memset(disp, 0, sizeof(*disp));
+       disp->modes = kmalloc(sizeof(struct videomode*), GFP_KERNEL);
+       if (!np)
+               return -EINVAL;
+
+       display_np = of_parse_phandle(np, "display", 0);
+
+       if (!display_np)
+               return -EINVAL;
+
+       of_property_read_u32(display_np, "width-mm", &disp->width_mm);
+       of_property_read_u32(display_np, "height-mm", &disp->height_mm);
+
+       mode_np = of_parse_phandle(np, "default-mode", 0);
+
+       if (!mode_np)
+               mode_np = of_find_node_by_name(np, "mode");
+
+       if (!mode_np)
+               return -EINVAL;
+
+       default_mode = (char *)mode_np->full_name;
+
+       modes_np = of_find_node_by_name(np, "modes");
+       for_each_child_of_node(modes_np, mode_np) {
+               struct videomode *vm;

Blank line after variable declarations, please.

+               vm = kmalloc(sizeof(struct videomode), GFP_KERNEL);
+               disp->modes[disp->num_modes] = kmalloc(sizeof(struct videomode*), GFP_KERNEL);

Are you sure this is right?

+               ret |= of_video_parse_property(mode_np, "hback-porch", &vm->hback_porch);
+               ret |= of_video_parse_property(mode_np, "hfront-porch", &vm->hfront_porch);
+               ret |= of_video_parse_property(mode_np, "hactive", &vm->hactive);
+               ret |= of_video_parse_property(mode_np, "hsync-len", &vm->hsync_len);
+               ret |= of_video_parse_property(mode_np, "vback-porch", &vm->vback_porch);
+               ret |= of_video_parse_property(mode_np, "vfront-porch", &vm->vfront_porch);
+               ret |= of_video_parse_property(mode_np, "vactive", &vm->vactive);
+               ret |= of_video_parse_property(mode_np, "vsync-len", &vm->vsync_len);
+               ret |= of_video_parse_property(mode_np, "clock", &vm->clock);
+
+               if (ret)
+                       return -EINVAL;
+
+               vm->hah = of_property_read_bool(mode_np, "hsync-active-high");
+               vm->vah = of_property_read_bool(mode_np, "vsync-active-high");
+               vm->interlaced = of_property_read_bool(mode_np, "interlaced");
+               vm->doublescan = of_property_read_bool(mode_np, "doublescan");
+
+               if (strcmp(default_mode,mode_np->full_name) = 0) {
+                       printk("%s: default_node = %d\n", __func__, disp->num_modes);

Please use a KERN_ macro here, or a pr_xxx function.  Even better
would be to use a dev_xxx function.

In general, I'd like to see more error reporting of bad device tree
properties, to help debugging.

+                       disp->default_mode = disp->num_modes;
+               }
+
+               disp->modes[disp->num_modes] = vm;

Isn't this a memory leak?

+               disp->num_modes++;
+       }
+       of_node_put(display_np);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(of_get_video_mode);

-- 
Timur Tabi
Linux kernel developer at Freescale