This patch adds a helper function for parsing videomodes from the devicetree. The videomode can be either converted to a struct drm_display_mode or a struct fb_videomode.
Signed-off-by: Sascha Hauer s.hauer@pengutronix.de Signed-off-by: Steffen Trumtrar s.trumtrar@pengutronix.de ---
Hi!
The original patch was done by Sascha Hauer. I reworked his v2 a "little" bit. Changes since v2: - use hardware-near property-names - provide a videomode structure - allow ranges for all properties (<min,typ,max>) - functions to get display_mode or fb_videomode
Regards, Steffen
.../devicetree/bindings/video/displaymode | 74 ++++++ drivers/of/Kconfig | 5 + drivers/of/Makefile | 1 + drivers/of/of_videomode.c | 236 ++++++++++++++++++++ include/linux/of_videomode.h | 56 +++++ 5 files changed, 372 insertions(+) create mode 100644 Documentation/devicetree/bindings/video/displaymode create mode 100644 drivers/of/of_videomode.c create mode 100644 include/linux/of_videomode.h
diff --git a/Documentation/devicetree/bindings/video/displaymode b/Documentation/devicetree/bindings/video/displaymode new file mode 100644 index 0000000..990ca52 --- /dev/null +++ b/Documentation/devicetree/bindings/video/displaymode @@ -0,0 +1,74 @@ +videomode bindings +================== + +Required properties: + - hactive, vactive: Display resolution + - hfront-porch, hback-porch, hsync-len: Horizontal Display timing parameters + in pixels + vfront-porch, vback-porch, vsync-len: Vertical display timing parameters in + lines + - clock: displayclock in Hz + +Optional properties: + - width-mm, height-mm: Display dimensions in mm + - hsync-active-high (bool): Hsync pulse is active high + - vsync-active-high (bool): Vsync pulse is active high + - interlaced (bool): This is an interlaced mode + - doublescan (bool): This is a doublescan mode + +There are different ways of describing a display mode. The devicetree representation +corresponds to the one commonly found in datasheets for displays. +The description of the display and its mode is split in two parts: first the display +properties like size in mm and (optionally) multiple subnodes with the supported modes. + +Example: + + display@0 { + width-mm = <800>; + height-mm = <480>; + modes { + mode0: mode@0 { + /* 1920x1080p24 */ + clock = <52000000>; + hactive = <1920>; + vactive = <1080>; + hfront-porch = <25>; + hback-porch = <25>; + hsync-len = <25>; + vback-porch = <2>; + vfront-porch = <2>; + vsync-len = <2>; + hsync-active-high; + }; + }; + }; + +Every property also supports the use of ranges, so the commonly used datasheet +description with <min typ max>-tuples can be used. + +Example: + + mode1: mode@1 { + /* 1920x1080p24 */ + clock = <148500000>; + hactive = <1920>; + vactive = <1080>; + hsync-len = <0 44 60>; + hfront-porch = <80 88 95>; + hback-porch = <100 148 160>; + vfront-porch = <0 4 6>; + vback-porch = <0 36 50>; + vsync-len = <0 5 6>; + }; + +The videomode can be linked to a connector via phandles. The connector has to +support the display- and default-mode-property to link to and select a mode. + +Example: + + hdmi@00120000 { + status = "okay"; + display = <&benq>; + default-mode = <&mode1>; + }; + diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index dfba3e6..a3acaa3 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -83,4 +83,9 @@ config OF_MTD depends on MTD def_bool y
+config OF_VIDEOMODE + def_bool y + help + helper to parse videomodes from the devicetree + endmenu # OF diff --git a/drivers/of/Makefile b/drivers/of/Makefile index e027f44..80e6db3 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -11,3 +11,4 @@ obj-$(CONFIG_OF_MDIO) += of_mdio.o obj-$(CONFIG_OF_PCI) += of_pci.o obj-$(CONFIG_OF_PCI_IRQ) += of_pci_irq.o obj-$(CONFIG_OF_MTD) += of_mtd.o +obj-$(CONFIG_OF_VIDEOMODE) += of_videomode.o diff --git a/drivers/of/of_videomode.c b/drivers/of/of_videomode.c new file mode 100644 index 0000000..217edf8 --- /dev/null +++ b/drivers/of/of_videomode.c @@ -0,0 +1,236 @@ +/* + * OF helpers for parsing display modes + * + * Copyright (c) 2012 Sascha Hauer s.hauer@pengutronix.de, Pengutronix + * Copyright (c) 2012 Steffen Trumtrar s.trumtrar@pengutronix.de, Pengutronix + * + * This file is released under the GPLv2 + */ +#include <linux/of.h> +#include <linux/fb.h> +#include <linux/export.h> +#include <linux/slab.h> +#include <drm/drmP.h> +#include <drm/drm_crtc.h> +#include <linux/of_videomode.h> + +/* 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); + 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)); + + if (index > disp->num_modes) + return -EINVAL; + vm = disp->modes[index]; + + dmode->hdisplay = of_video_get_value(&vm->hactive); + dmode->hsync_start = of_video_get_value(&vm->hactive) + of_video_get_value(&vm->hfront_porch); + dmode->hsync_end = of_video_get_value(&vm->hactive) + of_video_get_value(&vm->hfront_porch) + + of_video_get_value(&vm->hsync_len); + dmode->htotal = of_video_get_value(&vm->hactive) + of_video_get_value(&vm->hfront_porch) + + of_video_get_value(&vm->hsync_len) + of_video_get_value(&vm->hback_porch); + + dmode->vdisplay = of_video_get_value(&vm->vactive); + dmode->vsync_start = of_video_get_value(&vm->vactive) + of_video_get_value(&vm->vfront_porch); + dmode->vsync_end = of_video_get_value(&vm->vactive) + of_video_get_value(&vm->vfront_porch) + + of_video_get_value(&vm->vsync_len); + dmode->vtotal = of_video_get_value(&vm->vactive) + of_video_get_value(&vm->vfront_porch) + + of_video_get_value(&vm->vsync_len) + of_video_get_value(&vm->vback_porch); + + dmode->width_mm = disp->width_mm; + dmode->height_mm = disp->height_mm; + + dmode->clock = of_video_get_value(&vm->clock) / 1000; + + if (vm->hah) + dmode->flags |= DRM_MODE_FLAG_PHSYNC; + else + dmode->flags |= DRM_MODE_FLAG_NHSYNC; + if (vm->vah) + dmode->flags |= DRM_MODE_FLAG_PVSYNC; + else + dmode->flags |= DRM_MODE_FLAG_NVSYNC; + if (vm->interlaced) + dmode->flags |= DRM_MODE_FLAG_INTERLACE; + if (vm->doublescan) + dmode->flags |= DRM_MODE_FLAG_DBLSCAN; + + drm_mode_set_name(dmode); + return 0; +} +EXPORT_SYMBOL_GPL(videomode_to_display_mode); + +int videomode_to_fb_mode(struct display *disp, struct fb_videomode *fbmode, int index) +{ + struct videomode *vm; + memset(fbmode, 0, sizeof(*fbmode)); + + vm = disp->modes[index]; + + fbmode->xres = of_video_get_value(&vm->hactive); + fbmode->left_margin = of_video_get_value(&vm->hback_porch); + fbmode->right_margin = of_video_get_value(&vm->hfront_porch); + fbmode->hsync_len = of_video_get_value(&vm->hsync_len); + + fbmode->yres = of_video_get_value(&vm->vactive); + fbmode->upper_margin = of_video_get_value(&vm->vback_porch); + fbmode->lower_margin = of_video_get_value(&vm->vfront_porch); + fbmode->vsync_len = of_video_get_value(&vm->vsync_len); + + fbmode->pixclock = KHZ2PICOS(of_video_get_value(&vm->clock) / 1000); + + 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; + return 0; +} +EXPORT_SYMBOL_GPL(videomode_to_fb_mode); + +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; + vm = kmalloc(sizeof(struct videomode), GFP_KERNEL); + disp->modes[disp->num_modes] = kmalloc(sizeof(struct videomode*), GFP_KERNEL); + + 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); + disp->default_mode = disp->num_modes; + } + + disp->modes[disp->num_modes] = vm; + disp->num_modes++; + } + of_node_put(display_np); + + return 0; +} +EXPORT_SYMBOL_GPL(of_get_video_mode); + +int of_video_mode_exists(struct device_node *np) +{ + struct device_node *display_np; + struct device_node *mode_np; + + if (!np) + return -EINVAL; + + display_np = of_parse_phandle(np, "display", 0); + if (!display_np) + return -EINVAL; + mode_np = of_parse_phandle(np, "default-mode", 0); + if (mode_np) + return 0; + return -EINVAL; +} +EXPORT_SYMBOL_GPL(of_video_mode_exists); + +int of_get_display_mode(struct device_node *np, struct drm_display_mode *dmode, int index) +{ + struct display disp; + + of_get_video_mode(np, &disp); + if (index == OF_MODE_SELECTION) + index = disp.default_mode; + if (dmode) + videomode_to_display_mode(&disp, dmode, index); + + return 0; +} +EXPORT_SYMBOL_GPL(of_get_display_mode); + +int of_get_fb_videomode(struct device_node *np, struct fb_videomode *fbmode, int index) +{ + struct display disp; + + of_get_video_mode(np, &disp); + + if (fbmode) + videomode_to_fb_mode(&disp, fbmode, index); + + return 0; +} +EXPORT_SYMBOL_GPL(of_get_fb_videomode); diff --git a/include/linux/of_videomode.h b/include/linux/of_videomode.h new file mode 100644 index 0000000..a6b4da0 --- /dev/null +++ b/include/linux/of_videomode.h @@ -0,0 +1,56 @@ +/* + * Copyright 2012 Sascha Hauer s.hauer@pengutronix.de + * Copyright 2012 Steffen Trumtrar s.trumtrar@pengutronix.de + * + * OF helpers for videomodes. + * + * This file is released under the GPLv2 + */ + +#ifndef __LINUX_OF_VIDEOMODE_H +#define __LINUX_OF_VIDEOMODE_H + +#define OF_MODE_SELECTION -1 + +struct mode_property { + u32 min; + u32 typ; + u32 max; +}; + +struct display { + u32 width_mm; + u32 height_mm; + struct videomode **modes; + int default_mode; + int num_modes; +}; + +/* describe videomode in terms of hardware parameters */ +struct videomode { + struct mode_property hback_porch; + struct mode_property hfront_porch; + struct mode_property hactive; + struct mode_property hsync_len; + + struct mode_property vback_porch; + struct mode_property vfront_porch; + struct mode_property vactive; + struct mode_property vsync_len; + + struct mode_property clock; + + bool hah; + bool vah; + bool interlaced; + bool doublescan; +}; + +int of_video_mode_exists(struct device_node *np); +int videomode_to_display_mode(struct display *disp, struct drm_display_mode *dmode, int index); +int videomode_to_fb_mode(struct display *disp, struct fb_videomode *fbmode, int index); +int of_get_video_mode(struct device_node *np, struct display *disp); +int of_video_mode_exists(struct device_node *np); +int of_get_display_mode(struct device_node *np, struct drm_display_mode *dmode, int index); +int of_get_fb_videomode(struct device_node *np, struct fb_videomode *fbmode, int index); +#endif /* __LINUX_OF_VIDEOMODE_H */