diff mbox

[v3] video: Versatile Express DVI output driver

Message ID 1350405036-17997-1-git-send-email-pawel.moll@arm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Pawel Moll Oct. 16, 2012, 4:30 p.m. UTC
Versatile Express' DVI video output can be connected to one the three
sources - motherboard's CLCD controller or a video signal generated
by one of the daughterboards.

This driver configures the muxer FPGA so the output displays content
of one of the framebuffers in the system (0 by default, can be changed
by user writing to the "fb" sysfs attribute of the muxfpga device).

It will also set up the display formatter mode and keep it up
to date with mode changes requested by the user (eg. with fbset
tool).

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
---
 drivers/video/Makefile       |    3 +
 drivers/video/vexpress-dvi.c |  220 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 223 insertions(+)
 create mode 100644 drivers/video/vexpress-dvi.c

Hi Florian,

This is pretty much the same stuff I posted a month ago...
Other relevant changes are on their way to 3.8.

Would you be so kind and have a look at it?  If the code looks fine,
would you prefer to merge it yourself, or should I push it through
arm-soc tree?

Thanks!

Pawel

Comments

Pawel Moll Oct. 30, 2012, 3:58 p.m. UTC | #1
Hello again Florian,

On Tue, 2012-10-16 at 17:30 +0100, Pawel Moll wrote:
> Versatile Express' DVI video output can be connected to one the three
> sources - motherboard's CLCD controller or a video signal generated
> by one of the daughterboards.
> 
> This driver configures the muxer FPGA so the output displays content
> of one of the framebuffers in the system (0 by default, can be changed
> by user writing to the "fb" sysfs attribute of the muxfpga device).
> 
> It will also set up the display formatter mode and keep it up
> to date with mode changes requested by the user (eg. with fbset
> tool).
> 
> Signed-off-by: Pawel Moll <pawel.moll@arm.com>

It's just a polite a friendly nag regarding this patch - it's been 2
weeks since I posted this version (and 1.5 month since the first one)...

Does it look good enough or completely wrong?

Cheers!

Pawe?
Arnd Bergmann Nov. 19, 2012, 3:43 p.m. UTC | #2
On Monday 19 November 2012, Pawel Moll wrote:
> I've asked the framebuffer people 3 times about this but got no comment
> whatsoever:
> 
> https://patchwork.kernel.org/patch/1473091/
> https://patchwork.kernel.org/patch/1601781/
> 
> so I assume there is no problem with merging this code ;-) Therefore,
> would you be so kind to pull this single patch? Without it the 3.8
> kernel will not be able to show anything on VE's display...

Hi Pawel,

I have two comments for the patch that need to be fixed:

* vexpress_dvi_fb_select uses the 'fb' argument as an index into
  the registered_fb array, but does not check for overflow against
  FB_MAX. I think you need to use get_fb_info().

* There is no documentation for the newly introduced sysfs interface.

	Arnd
Pawel Moll Nov. 19, 2012, 4:26 p.m. UTC | #3
On Mon, 2012-11-19 at 15:43 +0000, Arnd Bergmann wrote:
> * vexpress_dvi_fb_select uses the 'fb' argument as an index into
>   the registered_fb array, but does not check for overflow against
>   FB_MAX. 

Uh, right. Will fix in a second.

> I think you need to use get_fb_info().

I was considering this, but it's a static. And I don't want to change
the fb core, as I'm planning to plug this driver into the "Generic
Panel/Display Framework" [1] that Laurent is working on when it's
available. Then I won't have to hack into the core at all...

[1] http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/52565

> * There is no documentation for the newly introduced sysfs interface.

Hm, I didn't want to do that, as it's currently just a debug feature -
there is no class symlink to the device available
(Documentation/ABI/testing/sysfs-devices) so there's no universal way of
describing the path to the device.

I'll do my best and post v4 soon.

Pawe?
diff mbox

Patch

diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 23e948e..2f4440d 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -167,3 +167,6 @@  obj-$(CONFIG_FB_VIRTUAL)          += vfb.o
 
 #video output switch sysfs driver
 obj-$(CONFIG_VIDEO_OUTPUT_CONTROL) += output.o
+
+# platform specific output drivers
+obj-$(CONFIG_VEXPRESS_CONFIG)	  += vexpress-dvi.o
diff --git a/drivers/video/vexpress-dvi.c b/drivers/video/vexpress-dvi.c
new file mode 100644
index 0000000..f087534
--- /dev/null
+++ b/drivers/video/vexpress-dvi.c
@@ -0,0 +1,220 @@ 
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Copyright (C) 2012 ARM Limited
+ */
+
+#define pr_fmt(fmt) "vexpress-dvi: " fmt
+
+#include <linux/fb.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/vexpress.h>
+
+
+static struct vexpress_config_func *vexpress_dvimode_func;
+
+static struct {
+	u32 xres, yres, mode;
+} vexpress_dvi_dvimodes[] = {
+	{ 640, 480, 0 }, /* VGA */
+	{ 800, 600, 1 }, /* SVGA */
+	{ 1024, 768, 2 }, /* XGA */
+	{ 1280, 1024, 3 }, /* SXGA */
+	{ 1600, 1200, 4 }, /* UXGA */
+	{ 1920, 1080, 5 }, /* HD1080 */
+};
+
+static void vexpress_dvi_mode_set(struct fb_info *info, u32 xres, u32 yres)
+{
+	int err = -ENOENT;
+	int i;
+
+	if (!vexpress_dvimode_func)
+		return;
+
+	for (i = 0; i < ARRAY_SIZE(vexpress_dvi_dvimodes); i++) {
+		if (vexpress_dvi_dvimodes[i].xres == xres &&
+				vexpress_dvi_dvimodes[i].yres == yres) {
+			pr_debug("mode: %ux%u = %d\n", xres, yres,
+					vexpress_dvi_dvimodes[i].mode);
+			err = vexpress_config_write(vexpress_dvimode_func, 0,
+					vexpress_dvi_dvimodes[i].mode);
+			break;
+		}
+	}
+
+	if (err)
+		pr_warn("Failed to set %ux%u mode! (%d)\n", xres, yres, err);
+}
+
+
+static struct vexpress_config_func *vexpress_muxfpga_func;
+static int vexpress_dvi_fb = -1;
+
+static int vexpress_dvi_mux_set(struct fb_info *info)
+{
+	int err;
+	u32 site = vexpress_get_site_by_dev(info->device);
+
+	if (!vexpress_muxfpga_func)
+		return -ENXIO;
+
+	err = vexpress_config_write(vexpress_muxfpga_func, 0, site);
+	if (!err) {
+		pr_debug("Selected MUXFPGA input %d (fb%d)\n", site,
+				info->node);
+		vexpress_dvi_fb = info->node;
+		vexpress_dvi_mode_set(info, info->var.xres,
+				info->var.yres);
+	} else {
+		pr_warn("Failed to select MUXFPGA input %d (fb%d)! (%d)\n",
+				site, info->node, err);
+	}
+
+	return err;
+}
+
+static int vexpress_dvi_fb_select(int fb)
+{
+	int err;
+	struct fb_info *info;
+
+	/* fb0 is the default */
+	if (fb < 0)
+		fb = 0;
+
+	info = registered_fb[fb];
+	if (!info || !lock_fb_info(info))
+		return -ENODEV;
+
+	err = vexpress_dvi_mux_set(info);
+
+	unlock_fb_info(info);
+
+	return err;
+}
+
+static ssize_t vexpress_dvi_fb_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", vexpress_dvi_fb);
+}
+
+static ssize_t vexpress_dvi_fb_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	long value;
+	int err = kstrtol(buf, 0, &value);
+
+	if (!err)
+		err = vexpress_dvi_fb_select(value);
+
+	return err ? err : count;
+}
+
+DEVICE_ATTR(fb, S_IRUGO | S_IWUSR, vexpress_dvi_fb_show,
+		vexpress_dvi_fb_store);
+
+
+static int vexpress_dvi_fb_event_notify(struct notifier_block *self,
+			      unsigned long action, void *data)
+{
+	struct fb_event *event = data;
+	struct fb_info *info = event->info;
+	struct fb_videomode *mode = event->data;
+
+	switch (action) {
+	case FB_EVENT_FB_REGISTERED:
+		if (vexpress_dvi_fb < 0)
+			vexpress_dvi_mux_set(info);
+		break;
+	case FB_EVENT_MODE_CHANGE:
+	case FB_EVENT_MODE_CHANGE_ALL:
+		if (info->node == vexpress_dvi_fb)
+			vexpress_dvi_mode_set(info, mode->xres, mode->yres);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block vexpress_dvi_fb_notifier = {
+	.notifier_call = vexpress_dvi_fb_event_notify,
+};
+static bool vexpress_dvi_fb_notifier_registered;
+
+
+enum vexpress_dvi_func { FUNC_MUXFPGA, FUNC_DVIMODE };
+
+static struct of_device_id vexpress_dvi_of_match[] = {
+	{
+		.compatible = "arm,vexpress-muxfpga",
+		.data = (void *)FUNC_MUXFPGA,
+	}, {
+		.compatible = "arm,vexpress-dvimode",
+		.data = (void *)FUNC_DVIMODE,
+	},
+	{}
+};
+
+static int vexpress_dvi_probe(struct platform_device *pdev)
+{
+	enum vexpress_dvi_func func;
+	const struct of_device_id *match =
+			of_match_device(vexpress_dvi_of_match, &pdev->dev);
+
+	if (match)
+		func = (enum vexpress_dvi_func)match->data;
+	else
+		func = pdev->id_entry->driver_data;
+
+	switch (func) {
+	case FUNC_MUXFPGA:
+		vexpress_muxfpga_func =
+				vexpress_config_func_get_by_dev(&pdev->dev);
+		device_create_file(&pdev->dev, &dev_attr_fb);
+		break;
+	case FUNC_DVIMODE:
+		vexpress_dvimode_func =
+				vexpress_config_func_get_by_dev(&pdev->dev);
+		break;
+	}
+
+	if (!vexpress_dvi_fb_notifier_registered) {
+		fb_register_client(&vexpress_dvi_fb_notifier);
+		vexpress_dvi_fb_notifier_registered = true;
+	}
+
+	vexpress_dvi_fb_select(vexpress_dvi_fb);
+
+	return 0;
+}
+
+static const struct platform_device_id vexpress_dvi_id_table[] = {
+	{ .name = "vexpress-muxfpga", .driver_data = FUNC_MUXFPGA, },
+	{ .name = "vexpress-dvimode", .driver_data = FUNC_DVIMODE, },
+	{}
+};
+
+static struct platform_driver vexpress_dvi_driver = {
+	.probe = vexpress_dvi_probe,
+	.driver = {
+		.name = "vexpress-dvi",
+		.of_match_table = vexpress_dvi_of_match,
+	},
+	.id_table = vexpress_dvi_id_table,
+};
+
+static int __init vexpress_dvi_init(void)
+{
+	return platform_driver_register(&vexpress_dvi_driver);
+}
+device_initcall(vexpress_dvi_init);