Re: [PATCHv14 4/7] fbmon: add videomode helpers

Hi Laurent,

On Fri, Nov 23, 2012 at 11:53:10AM +0100, Laurent Pinchart wrote:

Hi Steffen,

On Friday 23 November 2012 10:04:24 Steffen Trumtrar wrote:

quoted

Add a function to convert from the generic videomode to a fb_videomode.

Signed-off-by: Steffen Trumtrar <redacted>
Reviewed-by: Thierry Reding <redacted>
Acked-by: Thierry Reding <redacted>
Tested-by: Thierry Reding <redacted>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/video/fbmon.c |   49 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/fb.h    |    6 ++++++
 2 files changed, 55 insertions(+)

diff --git a/drivers/video/fbmon.c b/drivers/video/fbmon.c
index cef6557..bcbfe8f 100644
--- a/drivers/video/fbmon.c
+++ b/drivers/video/fbmon.c

@@ -31,6 +31,7 @@
 #include <linux/pci.h>
 #include <linux/slab.h>
 #include <video/edid.h>
+#include <linux/videomode.h>

You could move this one line up to keep headers sorted alphabetically 
(assuming they are in the first place).

Because of the careless mistake below, I will do that.

quoted

 #ifdef CONFIG_PPC_OF
 #include <asm/prom.h>
 #include <asm/pci-bridge.h>

@@ -1373,6 +1374,54 @@ int fb_get_mode(int flags, u32 val, struct

fb_var_screeninfo *var, struct fb_inf kfree(timings);
 	return err;
 }
+
+#if IS_ENABLED(CONFIG_VIDEOMODE)
+int fb_videomode_from_videomode(const struct videomode *vm,
+				struct fb_videomode *fbmode)

This is inside the #if CONFIG_FB_MODE_HELPERS block, is that intentional ?

Yes. Intentional. It is a fb_mode helper, that is why ... oh, wait. I should
add a "depends on" to the Kconfig then.

quoted

+{
+	unsigned int htotal, vtotal;
+
+	fbmode->xres = vm->hactive;
+	fbmode->left_margin = vm->hback_porch;
+	fbmode->right_margin = vm->hfront_porch;
+	fbmode->hsync_len = vm->hsync_len;
+
+	fbmode->yres = vm->vactive;
+	fbmode->upper_margin = vm->vback_porch;
+	fbmode->lower_margin = vm->vfront_porch;
+	fbmode->vsync_len = vm->vsync_len;
+
+	/* prevent division by zero in KHZ2PICOS macro */
+	fbmode->pixclock = vm->pixelclock ? KHZ2PICOS(vm->pixelclock / 1000) : 0;
+
+	fbmode->sync = 0;
+	fbmode->vmode = 0;
+	if (vm->hah)
+		fbmode->sync |= FB_SYNC_HOR_HIGH_ACT;
+	if (vm->vah)
+		fbmode->sync |= FB_SYNC_VERT_HIGH_ACT;
+	if (vm->interlaced)
+		fbmode->vmode |= FB_VMODE_INTERLACED;
+	if (vm->doublescan)
+		fbmode->vmode |= FB_VMODE_DOUBLE;
+	fbmode->flag = 0;
+
+	htotal = vm->hactive + vm->hfront_porch + vm->hback_porch +
+		 vm->hsync_len;
+	vtotal = vm->vactive + vm->vfront_porch + vm->vback_porch +
+		 vm->vsync_len;
+	/* prevent division by zero */
+	if (htotal && vtotal)
+		fbmode->refresh = vm->pixelclock / (htotal * vtotal);
+	else
+		fbmode->refresh = vm->pixelclock;

What about returning an error if htotal * vtotal = 0 ? The input is clearly 
invalid in that case. I would then set fbmode->refresh to 0, setting it to vm-

quoted

pixelclock doesn't really make sense.

Yes, pixelclock makes no sense. It was supposed to be 0. I was careless here.

quoted

+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(fb_videomode_from_videomode);
+#endif
+
+

A single blank line should be enough.

Regards,
Steffen

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |