| Message ID | 1353661467-28545-4-git-send-email-s.trumtrar@pengutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hello Steffen, On Fri, Nov 23, 2012 at 2:34 PM, Steffen Trumtrar <s.trumtrar@pengutronix.de> wrote: > This adds support for reading display timings from DT into a struct > display_timings. The of_display_timing implementation supports multiple > subnodes. All children are read into an array, that can be queried. > > If no native mode is specified, the first subnode will be used. > > For cases, where the graphics drivers knows, there can be only one > mode description or where the driver only supports one mode, a helper > function of_get_videomode is added, that gets a struct videomode from DT. > (As this function is implemented in an expensive fashion, it should only > be used in the aforementioned case). > > This also demonstrates how of_display_timings may be utilized. > > Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> > Acked-by: Stephen Warren <swarren@nvidia.com> > Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de> > Acked-by: Thierry Reding <thierry.reding@avionic-design.de> > Tested-by: Thierry Reding <thierry.reding@avionic-design.de> > Tested-by: Philipp Zabel <p.zabel@pengutronix.de> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > .../devicetree/bindings/video/display-timings.txt | 107 ++++++++++ > drivers/video/Kconfig | 15 ++ > drivers/video/Makefile | 2 + > drivers/video/of_display_timing.c | 223 ++++++++++++++++++++ > drivers/video/of_videomode.c | 48 +++++ > include/linux/of_display_timings.h | 20 ++ > include/linux/of_videomode.h | 18 ++ > 7 files changed, 433 insertions(+) > create mode 100644 Documentation/devicetree/bindings/video/display-timings.txt > create mode 100644 drivers/video/of_display_timing.c > create mode 100644 drivers/video/of_videomode.c > create mode 100644 include/linux/of_display_timings.h > create mode 100644 include/linux/of_videomode.h > <<<snip>>> > diff --git a/drivers/video/of_display_timing.c b/drivers/video/of_display_timing.c > new file mode 100644 > index 0000000..645f43d > --- /dev/null > +++ b/drivers/video/of_display_timing.c > @@ -0,0 +1,223 @@ > +/* > + * OF helpers for parsing display timings > + * > + * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix > + * > + * based on of_videomode.c by Sascha Hauer <s.hauer@pengutronix.de> > + * > + * This file is released under the GPLv2 > + */ > +#include <linux/of.h> > +#include <linux/slab.h> > +#include <linux/export.h> > +#include <linux/of_display_timings.h> > + > +/** > + * parse_property - parse timing_entry from device_node > + * @np: device_node with the property > + * @name: name of the property > + * @result: will be set to the return value > + * > + * DESCRIPTION: > + * Every display_timing can be specified with either just the typical value or > + * a range consisting of min/typ/max. This function helps handling this > + **/ > +static int parse_property(const struct device_node *np, const char *name, > + struct timing_entry *result) > +{ > + struct property *prop; > + int length, cells, ret; > + > + prop = of_find_property(np, name, &length); > + if (!prop) { > + pr_err("%s: could not find property %s\n", __func__, name); > + return -EINVAL; > + } > + > + cells = length / sizeof(u32); > + if (cells == 1) { > + ret = of_property_read_u32(np, name, &result->typ); > + result->min = result->typ; > + result->max = result->typ; > + } else if (cells == 3) { > + ret = of_property_read_u32_array(np, name, &result->min, cells); > + } else { > + pr_err("%s: illegal timing specification in %s\n", __func__, > + name); > + return -EINVAL; > + } > + > + return ret; > +} > + > +/** > + * of_get_display_timing - parse display_timing entry from device_node > + * @np: device_node with the properties > + **/ > +static struct display_timing *of_get_display_timing(const struct device_node > + *np) > +{ > + struct display_timing *dt; > + int ret = 0; > + > + dt = kzalloc(sizeof(*dt), GFP_KERNEL); > + if (!dt) { > + pr_err("%s: could not allocate display_timing struct\n", > + __func__); > + return NULL; > + } > + > + ret |= parse_property(np, "hback-porch", &dt->hback_porch); > + ret |= parse_property(np, "hfront-porch", &dt->hfront_porch); > + ret |= parse_property(np, "hactive", &dt->hactive); > + ret |= parse_property(np, "hsync-len", &dt->hsync_len); > + ret |= parse_property(np, "vback-porch", &dt->vback_porch); > + ret |= parse_property(np, "vfront-porch", &dt->vfront_porch); > + ret |= parse_property(np, "vactive", &dt->vactive); > + ret |= parse_property(np, "vsync-len", &dt->vsync_len); > + ret |= parse_property(np, "clock-frequency", &dt->pixelclock); > + > + of_property_read_u32(np, "vsync-active", &dt->vsync_pol_active); > + of_property_read_u32(np, "hsync-active", &dt->hsync_pol_active); > + of_property_read_u32(np, "de-active", &dt->de_pol_active); > + of_property_read_u32(np, "pixelclk-inverted", &dt->pixelclk_pol); > + dt->interlaced = of_property_read_bool(np, "interlaced"); > + dt->doublescan = of_property_read_bool(np, "doublescan"); > + > + if (ret) { > + pr_err("%s: error reading timing properties\n", __func__); > + kfree(dt); > + return NULL; > + } > + > + return dt; > +} > + > +/** > + * of_get_display_timings - parse all display_timing entries from a device_node > + * @np: device_node with the subnodes > + **/ > +struct display_timings *of_get_display_timings(struct device_node *np) > +{ > + struct device_node *timings_np; > + struct device_node *entry; > + struct device_node *native_mode; > + struct display_timings *disp; > + > + if (!np) { > + pr_err("%s: no devicenode given\n", __func__); > + return NULL; > + } > + > + timings_np = of_find_node_by_name(np, "display-timings"); > + if (!timings_np) { > + pr_err("%s: could not find display-timings node\n", __func__); > + return NULL; > + } > + > + disp = kzalloc(sizeof(*disp), GFP_KERNEL); > + if (!disp) { > + pr_err("%s: could not allocate struct disp'\n", __func__); > + goto dispfail; > + } > + > + entry = of_parse_phandle(timings_np, "native-mode", 0); > + /* assume first child as native mode if none provided */ > + if (!entry) > + entry = of_get_next_child(np, NULL); > + /* if there is no child, it is useless to go on */ > + if (!entry) { > + pr_err("%s: no timing specifications given\n", __func__); > + goto entryfail; > + } > + > + pr_info("%s: using %s as default timing\n", __func__, entry->name); > + > + native_mode = entry; > + > + disp->num_timings = of_get_child_count(timings_np); > + if (disp->num_timings == 0) { > + /* should never happen, as entry was already found above */ > + pr_err("%s: no timings specified\n", __func__); > + goto entryfail; > + } > + > + disp->timings = kzalloc(sizeof(struct display_timing *) * disp->num_timings, > + GFP_KERNEL); > + if (!disp->timings) { > + pr_err("%s: could not allocate timings array\n", __func__); > + goto entryfail; > + } > + > + disp->num_timings = 0; > + disp->native_mode = 0; > + > + for_each_child_of_node(timings_np, entry) { > + struct display_timing *dt; > + > + dt = of_get_display_timing(entry); > + if (!dt) { > + /* > + * to not encourage wrong devicetrees, fail in case of > + * an error > + */ > + pr_err("%s: error in timing %d\n", __func__, > + disp->num_timings + 1); > + goto timingfail; > + } > + > + if (native_mode == entry) > + disp->native_mode = disp->num_timings; > + > + disp->timings[disp->num_timings] = dt; > + disp->num_timings++; > + } > + of_node_put(timings_np); > + /* > + * native_mode points to the device_node returned by of_parse_phandle > + * therefore call of_node_put on it > + */ > + of_node_put(native_mode); > + > + if (disp->num_timings > 0) > + pr_info("%s: got %d timings. Using timing #%d as default\n", > + __func__, disp->num_timings, disp->native_mode + 1); > + else { > + pr_err("%s: no valid timings specified\n", __func__); > + display_timings_release(disp); > + return NULL; > + } > + return disp; > + > +timingfail: > + if (native_mode) > + of_node_put(native_mode); > + display_timings_release(disp); > +entryfail: > + if (disp) > + kfree(disp); > +dispfail: > + of_node_put(timings_np); > + return NULL; > +} > +EXPORT_SYMBOL_GPL(of_get_display_timings); > + > +/** > + * of_display_timings_exists - check if a display-timings node is provided > + * @np: device_node with the timing > + **/ > +int of_display_timings_exists(const struct device_node *np) > +{ > + struct device_node *timings_np; > + > + if (!np) > + return -EINVAL; > + > + timings_np = of_parse_phandle(np, "display-timings", 0); I'm seeing warning for the above call "passing argument 1 of 'of_parse_phandle' discards qualifiers from pointer target type expected 'struct device_node *' but argument is of type 'const struct device_node *' " Please take care of it. Best Wishes, Leela Krishna Amudala > + if (!timings_np) > + return -EINVAL; > + > + of_node_put(timings_np); > + return 1; > +} > +EXPORT_SYMBOL_GPL(of_display_timings_exists); > diff --git a/drivers/video/of_videomode.c b/drivers/video/of_videomode.c > new file mode 100644 > index 0000000..358aa56 > --- /dev/null > +++ b/drivers/video/of_videomode.c > @@ -0,0 +1,48 @@ > +/* > + * generic videomode helper > + * > + * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix > + * > + * This file is released under the GPLv2 > + */ > +#include <linux/of.h> > +#include <linux/of_display_timings.h> > +#include <linux/of_videomode.h> > +#include <linux/export.h> > + > +/** > + * of_get_videomode - get the videomode #<index> from devicetree > + * @np - devicenode with the display_timings > + * @vm - set to return value > + * @index - index into list of display_timings > + * DESCRIPTION: > + * Get a list of all display timings and put the one > + * specified by index into *vm. This function should only be used, if > + * only one videomode is to be retrieved. A driver that needs to work > + * with multiple/all videomodes should work with > + * of_get_display_timings instead. > + **/ > +int of_get_videomode(struct device_node *np, struct videomode *vm, > + int index) > +{ > + struct display_timings *disp; > + int ret; > + > + disp = of_get_display_timings(np); > + if (!disp) { > + pr_err("%s: no timings specified\n", __func__); > + return -EINVAL; > + } > + > + if (index == OF_USE_NATIVE_MODE) > + index = disp->native_mode; > + > + ret = videomode_from_timing(disp, vm, index); > + if (ret) > + return ret; > + > + display_timings_release(disp); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(of_get_videomode); > diff --git a/include/linux/of_display_timings.h b/include/linux/of_display_timings.h > new file mode 100644 > index 0000000..b3e3455 > --- /dev/null > +++ b/include/linux/of_display_timings.h > @@ -0,0 +1,20 @@ > +/* > + * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de> > + * > + * display timings of helpers > + * > + * This file is released under the GPLv2 > + */ > + > +#ifndef __LINUX_OF_DISPLAY_TIMINGS_H > +#define __LINUX_OF_DISPLAY_TIMINGS_H > + > +#include <linux/display_timing.h> > +#include <linux/of.h> > + > +#define OF_USE_NATIVE_MODE -1 > + > +struct display_timings *of_get_display_timings(struct device_node *np); > +int of_display_timings_exists(const struct device_node *np); > + > +#endif > diff --git a/include/linux/of_videomode.h b/include/linux/of_videomode.h > new file mode 100644 > index 0000000..a72ad78 > --- /dev/null > +++ b/include/linux/of_videomode.h > @@ -0,0 +1,18 @@ > +/* > + * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de> > + * > + * videomode of-helpers > + * > + * This file is released under the GPLv2 > + */ > + > +#ifndef __LINUX_OF_VIDEOMODE_H > +#define __LINUX_OF_VIDEOMODE_H > + > +#include <linux/videomode.h> > +#include <linux/of.h> > + > +int of_get_videomode(struct device_node *np, struct videomode *vm, > + int index); > + > +#endif /* __LINUX_OF_VIDEOMODE_H */ > -- > 1.7.10.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Nov 23, 2012 at 03:49:37PM +0530, Leela Krishna Amudala wrote: > Hello Steffen, > > On Fri, Nov 23, 2012 at 2:34 PM, Steffen Trumtrar > <s.trumtrar@pengutronix.de> wrote: > > This adds support for reading display timings from DT into a struct > > display_timings. The of_display_timing implementation supports multiple > > subnodes. All children are read into an array, that can be queried. > > > > If no native mode is specified, the first subnode will be used. > > > > For cases, where the graphics drivers knows, there can be only one > > mode description or where the driver only supports one mode, a helper > > function of_get_videomode is added, that gets a struct videomode from DT. > > (As this function is implemented in an expensive fashion, it should only > > be used in the aforementioned case). > > > > This also demonstrates how of_display_timings may be utilized. > > > > Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> > > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> > > Acked-by: Stephen Warren <swarren@nvidia.com> > > Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de> > > Acked-by: Thierry Reding <thierry.reding@avionic-design.de> > > Tested-by: Thierry Reding <thierry.reding@avionic-design.de> > > Tested-by: Philipp Zabel <p.zabel@pengutronix.de> > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > > Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > > --- > > .../devicetree/bindings/video/display-timings.txt | 107 ++++++++++ > > drivers/video/Kconfig | 15 ++ > > drivers/video/Makefile | 2 + > > drivers/video/of_display_timing.c | 223 ++++++++++++++++++++ > > drivers/video/of_videomode.c | 48 +++++ > > include/linux/of_display_timings.h | 20 ++ > > include/linux/of_videomode.h | 18 ++ > > 7 files changed, 433 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/video/display-timings.txt > > create mode 100644 drivers/video/of_display_timing.c > > create mode 100644 drivers/video/of_videomode.c > > create mode 100644 include/linux/of_display_timings.h > > create mode 100644 include/linux/of_videomode.h > > > > <<<snip>>> > > > diff --git a/drivers/video/of_display_timing.c b/drivers/video/of_display_timing.c > > new file mode 100644 > > index 0000000..645f43d > > --- /dev/null > > +++ b/drivers/video/of_display_timing.c > > @@ -0,0 +1,223 @@ > > +/* > > + * OF helpers for parsing display timings > > + * > > + * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix > > + * > > + * based on of_videomode.c by Sascha Hauer <s.hauer@pengutronix.de> > > + * > > + * This file is released under the GPLv2 > > + */ > > +#include <linux/of.h> > > +#include <linux/slab.h> > > +#include <linux/export.h> > > +#include <linux/of_display_timings.h> > > + > > +/** > > + * parse_property - parse timing_entry from device_node > > + * @np: device_node with the property > > + * @name: name of the property > > + * @result: will be set to the return value > > + * > > + * DESCRIPTION: > > + * Every display_timing can be specified with either just the typical value or > > + * a range consisting of min/typ/max. This function helps handling this > > + **/ > > +static int parse_property(const struct device_node *np, const char *name, > > + struct timing_entry *result) > > +{ > > + struct property *prop; > > + int length, cells, ret; > > + > > + prop = of_find_property(np, name, &length); > > + if (!prop) { > > + pr_err("%s: could not find property %s\n", __func__, name); > > + return -EINVAL; > > + } > > + > > + cells = length / sizeof(u32); > > + if (cells == 1) { > > + ret = of_property_read_u32(np, name, &result->typ); > > + result->min = result->typ; > > + result->max = result->typ; > > + } else if (cells == 3) { > > + ret = of_property_read_u32_array(np, name, &result->min, cells); > > + } else { > > + pr_err("%s: illegal timing specification in %s\n", __func__, > > + name); > > + return -EINVAL; > > + } > > + > > + return ret; > > +} > > + > > +/** > > + * of_get_display_timing - parse display_timing entry from device_node > > + * @np: device_node with the properties > > + **/ > > +static struct display_timing *of_get_display_timing(const struct device_node > > + *np) > > +{ > > + struct display_timing *dt; > > + int ret = 0; > > + > > + dt = kzalloc(sizeof(*dt), GFP_KERNEL); > > + if (!dt) { > > + pr_err("%s: could not allocate display_timing struct\n", > > + __func__); > > + return NULL; > > + } > > + > > + ret |= parse_property(np, "hback-porch", &dt->hback_porch); > > + ret |= parse_property(np, "hfront-porch", &dt->hfront_porch); > > + ret |= parse_property(np, "hactive", &dt->hactive); > > + ret |= parse_property(np, "hsync-len", &dt->hsync_len); > > + ret |= parse_property(np, "vback-porch", &dt->vback_porch); > > + ret |= parse_property(np, "vfront-porch", &dt->vfront_porch); > > + ret |= parse_property(np, "vactive", &dt->vactive); > > + ret |= parse_property(np, "vsync-len", &dt->vsync_len); > > + ret |= parse_property(np, "clock-frequency", &dt->pixelclock); > > + > > + of_property_read_u32(np, "vsync-active", &dt->vsync_pol_active); > > + of_property_read_u32(np, "hsync-active", &dt->hsync_pol_active); > > + of_property_read_u32(np, "de-active", &dt->de_pol_active); > > + of_property_read_u32(np, "pixelclk-inverted", &dt->pixelclk_pol); > > + dt->interlaced = of_property_read_bool(np, "interlaced"); > > + dt->doublescan = of_property_read_bool(np, "doublescan"); > > + > > + if (ret) { > > + pr_err("%s: error reading timing properties\n", __func__); > > + kfree(dt); > > + return NULL; > > + } > > + > > + return dt; > > +} > > + > > +/** > > + * of_get_display_timings - parse all display_timing entries from a device_node > > + * @np: device_node with the subnodes > > + **/ > > +struct display_timings *of_get_display_timings(struct device_node *np) > > +{ > > + struct device_node *timings_np; > > + struct device_node *entry; > > + struct device_node *native_mode; > > + struct display_timings *disp; > > + > > + if (!np) { > > + pr_err("%s: no devicenode given\n", __func__); > > + return NULL; > > + } > > + > > + timings_np = of_find_node_by_name(np, "display-timings"); > > + if (!timings_np) { > > + pr_err("%s: could not find display-timings node\n", __func__); > > + return NULL; > > + } > > + > > + disp = kzalloc(sizeof(*disp), GFP_KERNEL); > > + if (!disp) { > > + pr_err("%s: could not allocate struct disp'\n", __func__); > > + goto dispfail; > > + } > > + > > + entry = of_parse_phandle(timings_np, "native-mode", 0); > > + /* assume first child as native mode if none provided */ > > + if (!entry) > > + entry = of_get_next_child(np, NULL); > > + /* if there is no child, it is useless to go on */ > > + if (!entry) { > > + pr_err("%s: no timing specifications given\n", __func__); > > + goto entryfail; > > + } > > + > > + pr_info("%s: using %s as default timing\n", __func__, entry->name); > > + > > + native_mode = entry; > > + > > + disp->num_timings = of_get_child_count(timings_np); > > + if (disp->num_timings == 0) { > > + /* should never happen, as entry was already found above */ > > + pr_err("%s: no timings specified\n", __func__); > > + goto entryfail; > > + } > > + > > + disp->timings = kzalloc(sizeof(struct display_timing *) * disp->num_timings, > > + GFP_KERNEL); > > + if (!disp->timings) { > > + pr_err("%s: could not allocate timings array\n", __func__); > > + goto entryfail; > > + } > > + > > + disp->num_timings = 0; > > + disp->native_mode = 0; > > + > > + for_each_child_of_node(timings_np, entry) { > > + struct display_timing *dt; > > + > > + dt = of_get_display_timing(entry); > > + if (!dt) { > > + /* > > + * to not encourage wrong devicetrees, fail in case of > > + * an error > > + */ > > + pr_err("%s: error in timing %d\n", __func__, > > + disp->num_timings + 1); > > + goto timingfail; > > + } > > + > > + if (native_mode == entry) > > + disp->native_mode = disp->num_timings; > > + > > + disp->timings[disp->num_timings] = dt; > > + disp->num_timings++; > > + } > > + of_node_put(timings_np); > > + /* > > + * native_mode points to the device_node returned by of_parse_phandle > > + * therefore call of_node_put on it > > + */ > > + of_node_put(native_mode); > > + > > + if (disp->num_timings > 0) > > + pr_info("%s: got %d timings. Using timing #%d as default\n", > > + __func__, disp->num_timings, disp->native_mode + 1); > > + else { > > + pr_err("%s: no valid timings specified\n", __func__); > > + display_timings_release(disp); > > + return NULL; > > + } > > + return disp; > > + > > +timingfail: > > + if (native_mode) > > + of_node_put(native_mode); > > + display_timings_release(disp); > > +entryfail: > > + if (disp) > > + kfree(disp); > > +dispfail: > > + of_node_put(timings_np); > > + return NULL; > > +} > > +EXPORT_SYMBOL_GPL(of_get_display_timings); > > + > > +/** > > + * of_display_timings_exists - check if a display-timings node is provided > > + * @np: device_node with the timing > > + **/ > > +int of_display_timings_exists(const struct device_node *np) > > +{ > > + struct device_node *timings_np; > > + > > + if (!np) > > + return -EINVAL; > > + > > + timings_np = of_parse_phandle(np, "display-timings", 0); > > I'm seeing warning for the above call > "passing argument 1 of 'of_parse_phandle' discards qualifiers from > pointer target type > expected 'struct device_node *' but argument is of type 'const struct > device_node *' " > Please take care of it. > I already sent a patch for of_parse_phandle that makes its device_node pointer const. That fixes this warning. As I got that patch also on my tree, I did miss removing the const for the time being. Regards, Steffen
diff --git a/Documentation/devicetree/bindings/video/display-timings.txt b/Documentation/devicetree/bindings/video/display-timings.txt new file mode 100644 index 0000000..2b25d58 --- /dev/null +++ b/Documentation/devicetree/bindings/video/display-timings.txt @@ -0,0 +1,107 @@ +display-timings bindings +======================== + +display-timings node +-------------------- + +required properties: + - none + +optional properties: + - native-mode: The native mode for the display, in case multiple modes are + provided. When omitted, assume the first node is the native. + +timings subnode +--------------- + +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-frequency: display clock in Hz + +optional properties: + - hsync-active: Hsync pulse is active low/high/ignored + - vsync-active: Vsync pulse is active low/high/ignored + - de-active: Data-Enable pulse is active low/high/ignored + - pixelclk-inverted: pixelclock is inverted (active on falling edge)/ + non-inverted (active on rising edge)/ + ignored (ignore property) + - interlaced (bool): boolean to enable interlaced mode + - doublescan (bool): boolean to enable doublescan mode + - doubleclk (bool) + +All the optional properties that are not bool follow the following logic: + <1>: high active + <0>: low active + omitted: not used on hardware + +There are different ways of describing the capabilities of a display. The devicetree +representation corresponds to the one commonly found in datasheets for displays. +If a display supports multiple signal timings, the native-mode can be specified. + +The parameters are defined as + + +----------+---------------------------------------------+----------+-------+ + | | ? | | | + | | |vback_porch | | | + | | ? | | | + +----------###############################################----------+-------+ + | # ? # | | + | # | # | | + | hback # | # hfront | hsync | + | porch # | hactive # porch | len | + |<-------->#<---------------+--------------------------->#<-------->|<----->| + | # | # | | + | # |vactive # | | + | # | # | | + | # ? # | | + +----------###############################################----------+-------+ + | | ? | | | + | | |vfront_porch | | | + | | ? | | | + +----------+---------------------------------------------+----------+-------+ + | | ? | | | + | | |vsync_len | | | + | | ? | | | + +----------+---------------------------------------------+----------+-------+ + + +Example: + + display-timings { + native-mode = <&timing0>; + timing0: 1080p24 { + /* 1920x1080p24 */ + clock-frequency = <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 = <1>; + }; + }; + +Every required property also supports the use of ranges, so the commonly used +datasheet description with <min typ max>-tuples can be used. + +Example: + + timing1: timing { + /* 1920x1080p24 */ + clock-frequency = <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>; + }; diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig index 2a23b18..c5b7bcf 100644 --- a/drivers/video/Kconfig +++ b/drivers/video/Kconfig @@ -39,6 +39,21 @@ config DISPLAY_TIMING config VIDEOMODE bool +config OF_DISPLAY_TIMING + bool "Enable OF display timing support" + depends on OF + select DISPLAY_TIMING + help + helper to parse display timings from the devicetree + +config OF_VIDEOMODE + bool "Enable OF videomode support" + depends on OF + select VIDEOMODE + select OF_DISPLAY_TIMING + help + helper to get videomodes from the devicetree + menuconfig FB tristate "Support for frame buffer devices" ---help--- diff --git a/drivers/video/Makefile b/drivers/video/Makefile index fc30439..b936b00 100644 --- a/drivers/video/Makefile +++ b/drivers/video/Makefile @@ -168,4 +168,6 @@ obj-$(CONFIG_FB_VIRTUAL) += vfb.o #video output switch sysfs driver obj-$(CONFIG_VIDEO_OUTPUT_CONTROL) += output.o obj-$(CONFIG_DISPLAY_TIMING) += display_timing.o +obj-$(CONFIG_OF_DISPLAY_TIMING) += of_display_timing.o obj-$(CONFIG_VIDEOMODE) += videomode.o +obj-$(CONFIG_OF_VIDEOMODE) += of_videomode.o diff --git a/drivers/video/of_display_timing.c b/drivers/video/of_display_timing.c new file mode 100644 index 0000000..645f43d --- /dev/null +++ b/drivers/video/of_display_timing.c @@ -0,0 +1,223 @@ +/* + * OF helpers for parsing display timings + * + * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix + * + * based on of_videomode.c by Sascha Hauer <s.hauer@pengutronix.de> + * + * This file is released under the GPLv2 + */ +#include <linux/of.h> +#include <linux/slab.h> +#include <linux/export.h> +#include <linux/of_display_timings.h> + +/** + * parse_property - parse timing_entry from device_node + * @np: device_node with the property + * @name: name of the property + * @result: will be set to the return value + * + * DESCRIPTION: + * Every display_timing can be specified with either just the typical value or + * a range consisting of min/typ/max. This function helps handling this + **/ +static int parse_property(const struct device_node *np, const char *name, + struct timing_entry *result) +{ + struct property *prop; + int length, cells, ret; + + prop = of_find_property(np, name, &length); + if (!prop) { + pr_err("%s: could not find property %s\n", __func__, name); + return -EINVAL; + } + + cells = length / sizeof(u32); + if (cells == 1) { + ret = of_property_read_u32(np, name, &result->typ); + result->min = result->typ; + result->max = result->typ; + } else if (cells == 3) { + ret = of_property_read_u32_array(np, name, &result->min, cells); + } else { + pr_err("%s: illegal timing specification in %s\n", __func__, + name); + return -EINVAL; + } + + return ret; +} + +/** + * of_get_display_timing - parse display_timing entry from device_node + * @np: device_node with the properties + **/ +static struct display_timing *of_get_display_timing(const struct device_node + *np) +{ + struct display_timing *dt; + int ret = 0; + + dt = kzalloc(sizeof(*dt), GFP_KERNEL); + if (!dt) { + pr_err("%s: could not allocate display_timing struct\n", + __func__); + return NULL; + } + + ret |= parse_property(np, "hback-porch", &dt->hback_porch); + ret |= parse_property(np, "hfront-porch", &dt->hfront_porch); + ret |= parse_property(np, "hactive", &dt->hactive); + ret |= parse_property(np, "hsync-len", &dt->hsync_len); + ret |= parse_property(np, "vback-porch", &dt->vback_porch); + ret |= parse_property(np, "vfront-porch", &dt->vfront_porch); + ret |= parse_property(np, "vactive", &dt->vactive); + ret |= parse_property(np, "vsync-len", &dt->vsync_len); + ret |= parse_property(np, "clock-frequency", &dt->pixelclock); + + of_property_read_u32(np, "vsync-active", &dt->vsync_pol_active); + of_property_read_u32(np, "hsync-active", &dt->hsync_pol_active); + of_property_read_u32(np, "de-active", &dt->de_pol_active); + of_property_read_u32(np, "pixelclk-inverted", &dt->pixelclk_pol); + dt->interlaced = of_property_read_bool(np, "interlaced"); + dt->doublescan = of_property_read_bool(np, "doublescan"); + + if (ret) { + pr_err("%s: error reading timing properties\n", __func__); + kfree(dt); + return NULL; + } + + return dt; +} + +/** + * of_get_display_timings - parse all display_timing entries from a device_node + * @np: device_node with the subnodes + **/ +struct display_timings *of_get_display_timings(struct device_node *np) +{ + struct device_node *timings_np; + struct device_node *entry; + struct device_node *native_mode; + struct display_timings *disp; + + if (!np) { + pr_err("%s: no devicenode given\n", __func__); + return NULL; + } + + timings_np = of_find_node_by_name(np, "display-timings"); + if (!timings_np) { + pr_err("%s: could not find display-timings node\n", __func__); + return NULL; + } + + disp = kzalloc(sizeof(*disp), GFP_KERNEL); + if (!disp) { + pr_err("%s: could not allocate struct disp'\n", __func__); + goto dispfail; + } + + entry = of_parse_phandle(timings_np, "native-mode", 0); + /* assume first child as native mode if none provided */ + if (!entry) + entry = of_get_next_child(np, NULL); + /* if there is no child, it is useless to go on */ + if (!entry) { + pr_err("%s: no timing specifications given\n", __func__); + goto entryfail; + } + + pr_info("%s: using %s as default timing\n", __func__, entry->name); + + native_mode = entry; + + disp->num_timings = of_get_child_count(timings_np); + if (disp->num_timings == 0) { + /* should never happen, as entry was already found above */ + pr_err("%s: no timings specified\n", __func__); + goto entryfail; + } + + disp->timings = kzalloc(sizeof(struct display_timing *) * disp->num_timings, + GFP_KERNEL); + if (!disp->timings) { + pr_err("%s: could not allocate timings array\n", __func__); + goto entryfail; + } + + disp->num_timings = 0; + disp->native_mode = 0; + + for_each_child_of_node(timings_np, entry) { + struct display_timing *dt; + + dt = of_get_display_timing(entry); + if (!dt) { + /* + * to not encourage wrong devicetrees, fail in case of + * an error + */ + pr_err("%s: error in timing %d\n", __func__, + disp->num_timings + 1); + goto timingfail; + } + + if (native_mode == entry) + disp->native_mode = disp->num_timings; + + disp->timings[disp->num_timings] = dt; + disp->num_timings++; + } + of_node_put(timings_np); + /* + * native_mode points to the device_node returned by of_parse_phandle + * therefore call of_node_put on it + */ + of_node_put(native_mode); + + if (disp->num_timings > 0) + pr_info("%s: got %d timings. Using timing #%d as default\n", + __func__, disp->num_timings, disp->native_mode + 1); + else { + pr_err("%s: no valid timings specified\n", __func__); + display_timings_release(disp); + return NULL; + } + return disp; + +timingfail: + if (native_mode) + of_node_put(native_mode); + display_timings_release(disp); +entryfail: + if (disp) + kfree(disp); +dispfail: + of_node_put(timings_np); + return NULL; +} +EXPORT_SYMBOL_GPL(of_get_display_timings); + +/** + * of_display_timings_exists - check if a display-timings node is provided + * @np: device_node with the timing + **/ +int of_display_timings_exists(const struct device_node *np) +{ + struct device_node *timings_np; + + if (!np) + return -EINVAL; + + timings_np = of_parse_phandle(np, "display-timings", 0); + if (!timings_np) + return -EINVAL; + + of_node_put(timings_np); + return 1; +} +EXPORT_SYMBOL_GPL(of_display_timings_exists); diff --git a/drivers/video/of_videomode.c b/drivers/video/of_videomode.c new file mode 100644 index 0000000..358aa56 --- /dev/null +++ b/drivers/video/of_videomode.c @@ -0,0 +1,48 @@ +/* + * generic videomode helper + * + * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix + * + * This file is released under the GPLv2 + */ +#include <linux/of.h> +#include <linux/of_display_timings.h> +#include <linux/of_videomode.h> +#include <linux/export.h> + +/** + * of_get_videomode - get the videomode #<index> from devicetree + * @np - devicenode with the display_timings + * @vm - set to return value + * @index - index into list of display_timings + * DESCRIPTION: + * Get a list of all display timings and put the one + * specified by index into *vm. This function should only be used, if + * only one videomode is to be retrieved. A driver that needs to work + * with multiple/all videomodes should work with + * of_get_display_timings instead. + **/ +int of_get_videomode(struct device_node *np, struct videomode *vm, + int index) +{ + struct display_timings *disp; + int ret; + + disp = of_get_display_timings(np); + if (!disp) { + pr_err("%s: no timings specified\n", __func__); + return -EINVAL; + } + + if (index == OF_USE_NATIVE_MODE) + index = disp->native_mode; + + ret = videomode_from_timing(disp, vm, index); + if (ret) + return ret; + + display_timings_release(disp); + + return 0; +} +EXPORT_SYMBOL_GPL(of_get_videomode); diff --git a/include/linux/of_display_timings.h b/include/linux/of_display_timings.h new file mode 100644 index 0000000..b3e3455 --- /dev/null +++ b/include/linux/of_display_timings.h @@ -0,0 +1,20 @@ +/* + * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de> + * + * display timings of helpers + * + * This file is released under the GPLv2 + */ + +#ifndef __LINUX_OF_DISPLAY_TIMINGS_H +#define __LINUX_OF_DISPLAY_TIMINGS_H + +#include <linux/display_timing.h> +#include <linux/of.h> + +#define OF_USE_NATIVE_MODE -1 + +struct display_timings *of_get_display_timings(struct device_node *np); +int of_display_timings_exists(const struct device_node *np); + +#endif diff --git a/include/linux/of_videomode.h b/include/linux/of_videomode.h new file mode 100644 index 0000000..a72ad78 --- /dev/null +++ b/include/linux/of_videomode.h @@ -0,0 +1,18 @@ +/* + * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de> + * + * videomode of-helpers + * + * This file is released under the GPLv2 + */ + +#ifndef __LINUX_OF_VIDEOMODE_H +#define __LINUX_OF_VIDEOMODE_H + +#include <linux/videomode.h> +#include <linux/of.h> + +int of_get_videomode(struct device_node *np, struct videomode *vm, + int index); + +#endif /* __LINUX_OF_VIDEOMODE_H */