On Tue, Sep 26, 2017 at 01:32:15PM +0200, Daniel Vetter wrote: > On Tue, Sep 26, 2017 at 04:46:53PM +0530, Meghana Madhyastha wrote: > > On Mon, Sep 25, 2017 at 06:31:58PM +0200, Noralf Trønnes wrote: > > > > > > Den 25.09.2017 16.56, skrev Noralf Trønnes: > > > >Hi Meghana, > > > > > > > > > > > >Den 22.09.2017 17.09, skrev Meghana Madhyastha: > > > >>Move backlight helpers from tinydrm-helpers.c to > > > >>tinydrm-backlight.c. This is because it is organizationally > > > >>simpler to understand and advantageous to group functions > > > >>performing a similar function to a separate file as opposed to > > > >>having one helper file with heteregenous helper functions. > > > >> > > > >>Signed-off-by: Meghana Madhyastha <meghana.madhyastha@xxxxxxxxx> > > > >>--- > > > > > > > >I don't think there is much gain in just moving the code like this. > > > > > > > >The idea is to add a drm_backlight helper that can be useful for all > > > >DRM drivers that use the backlight subsystem. > > > > Yes I agree. That definitely makes more sense. > > > > > > The full path to that helper would be: > > > drivers/gpu/drm/drm_backlight.c > > > > > > >This is what the TODO says: > > > >https://dri.freedesktop.org/docs/drm/gpu/todo.html#tinydrm > > > > > > > >- backlight helpers, probably best to put them into a new drm_backlight.c. > > > > This is because drivers/video is de-facto unmaintained. We could also > > > > move drivers/video/backlight to drivers/gpu/backlight and take it all > > > > over within drm-misc, but that’s more work. > > > > > > > >There is also this discussion to take into account: > > > >KMS backlight ABI proposition > > > >https://lists.freedesktop.org/archives/dri-devel/2017-February/133206.html > > > > > > > > > > > >I don't remember what came out of that discussion. > > > > > > > >Noralf. > > > > After having discussed this with Daniel on the #dri-devel irc channel, > > here are some of the points suggested. > > > > Daniel suggested that I first look into the usage of shared backlight > > helpers in drm (specifically backlight_update_status to begin with). The idea > > was to see whether there is any pattern in usage and/or code dupication. > > If there is, then the next step would be to write helper functions which > > can be used by other drivers (and not just tinydrm). > > > > To start with, I went through the instances of backlight_update_status > > in the drm code, and made the following observations(most of them are > > very simple/naive observations). > > > > - backlight_update_status is usually called in backlight init (and > > sometimes exit) functions of the drivers just after the device is registered. > > So backlight_update_status is called with the registered device as the > > parameter. > > > > Here are the following cases of properties changed/set before > > backlight_update_status is called. > > > > - CASE 1: Brightness is changed (either a macro BRIGHTNESS_MAX_LEVEL 100 > > is defined or it is manually set) This happens in the following files: > > > > gma500/cdv_device.c, gma500/mdfld_device.c, gma500/oaktrail_device.c, > > gma500/psb_device.c, noveau/noveau_backlight.c(here brightness is determined by fuction > > static int nv50_get_intensity) > > > > - CASE 2: Power property is set (to FB_BLANK_UNBLANK mostly) > > This happens in the following files: > > > > omapdrm/displays/panel-dpi.c, panel/panel-innolux-p079zca.c, > > panel/panel-jdi-lt070me05000.c, panel/panel-sharp-lq101r1sx01.c, > > panel/panel-sharp-ls043t1le01.c, tilcdc/tilcdc_panel.c > > > > - CASE 3: State is set > > This happens in the following files: > > > > tinydrm/tinydrm-helpers.c > > > > - CASE 4: Power and brightness properties are set > > This happens in the following files: > > > > atombios_encoders.c, radeon/radeon_legacy_encoders.c, > > shmobile/shmob_drm_backlight.c > > > > - CASE 5: Power and the state properties are set > > This happens in the following files: > > > > panel/panel-lvds.c, panel/panel-panasonic-vvx10f034n00.c, > > panel/panel-simple.c, panel/panel-sitronix-st7789v.c > > > > Please let me know if I am wrong / missed something. As for next steps, > > wouldn't it be an overkill to have a separate helper function for each > > of these cases ? Perhaps a generic helper function which would somehow > > address these cases would be more appropriate ? Thank you for your > > time/patience. > > I suspect that a lot of these combinations are just plain wrong, but > happen to kinda work with the combination of gpu driver and backlight > driver they're used on. tbh I have no idea which one is the correct > version for enabling a backlight correctly ... So does this mean that different devices require different combinations in order to enable a backlight ? Is it wrong or is it just that it depends on the gpu driver ? > So definitely a good task to refactor this into a proper helper, but looks > a lot more involved than at first sight. Yes it does look more involved than it did initially. Would a good starting point be then to try to find out if there is one common combination that can be used to enable any backlight device of any gpu driver ? > Do you have any of the hardware supported by any of these drivers? lsmod > and then comparing with the modules you're building in your own tree > should help you figure this out. > -Daniel I don't have all of the hardware. However, some of the modules such as radeon, amdgpu and gma500 drivers were successfully loaded so my system supports some of the hardware. -Meghana > > > > -Meghana > > > > > >>Changes in v2: > > > >> -Improved commit message by explaining why the changes were made. > > > >> > > > >> drivers/gpu/drm/tinydrm/core/Makefile | 2 +- > > > >> drivers/gpu/drm/tinydrm/core/tinydrm-backlight.c | 103 > > > >>+++++++++++++++++++++++ > > > >> drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c | 94 > > > >>--------------------- > > > >> drivers/gpu/drm/tinydrm/mi0283qt.c | 1 + > > > >> drivers/gpu/drm/tinydrm/mipi-dbi.c | 1 + > > > >> include/drm/tinydrm/tinydrm-backlight.h | 18 ++++ > > > >> 6 files changed, 124 insertions(+), 95 deletions(-) > > > >> create mode 100644 drivers/gpu/drm/tinydrm/core/tinydrm-backlight.c > > > >> create mode 100644 include/drm/tinydrm/tinydrm-backlight.h > > > >> > > > >>diff --git a/drivers/gpu/drm/tinydrm/core/Makefile > > > >>b/drivers/gpu/drm/tinydrm/core/Makefile > > > >>index fb221e6..389ca7a 100644 > > > >>--- a/drivers/gpu/drm/tinydrm/core/Makefile > > > >>+++ b/drivers/gpu/drm/tinydrm/core/Makefile > > > >>@@ -1,3 +1,3 @@ > > > >>-tinydrm-y := tinydrm-core.o tinydrm-pipe.o tinydrm-helpers.o > > > >>+tinydrm-y := tinydrm-core.o tinydrm-pipe.o tinydrm-backlight.o > > > >>tinydrm-helpers.o > > > >> obj-$(CONFIG_DRM_TINYDRM) += tinydrm.o > > > >>diff --git a/drivers/gpu/drm/tinydrm/core/tinydrm-backlight.c > > > >>b/drivers/gpu/drm/tinydrm/core/tinydrm-backlight.c > > > >>new file mode 100644 > > > >>index 0000000..dc6f17d > > > >>--- /dev/null > > > >>+++ b/drivers/gpu/drm/tinydrm/core/tinydrm-backlight.c > > > >>@@ -0,0 +1,103 @@ > > > >>+#include <linux/backlight.h> > > > >>+#include <linux/dma-buf.h> > > > >>+#include <linux/pm.h> > > > >>+#include <linux/swab.h> > > > >>+ > > > >>+#include <drm/tinydrm/tinydrm.h> > > > >>+#include <drm/tinydrm/tinydrm-backlight.h> > > > >>+ > > > >>+/** > > > >>+ * tinydrm_of_find_backlight - Find backlight device in device-tree > > > >>+ * @dev: Device > > > >>+ * > > > >>+ * This function looks for a DT node pointed to by a property named > > > >>'backlight' > > > >>+ * and uses of_find_backlight_by_node() to get the backlight device. > > > >>+ * Additionally if the brightness property is zero, it is set to > > > >>+ * max_brightness. > > > >>+ * > > > >>+ * Returns: > > > >>+ * NULL if there's no backlight property. > > > >>+ * Error pointer -EPROBE_DEFER if the DT node is found, but no > > > >>backlight device > > > >>+ * is found. > > > >>+ * If the backlight device is found, a pointer to the structure is > > > >>returned. > > > >>+ */ > > > >>+ > > > >>+struct backlight_device *tinydrm_of_find_backlight(struct device *dev) > > > >>+{ > > > >>+ struct backlight_device *backlight; > > > >>+ struct device_node *np; > > > >>+ > > > >>+ np = of_parse_phandle(dev->of_node, "backlight", 0); > > > >>+ if (!np) > > > >>+ return NULL; > > > >>+ > > > >>+ backlight = of_find_backlight_by_node(np); > > > >>+ of_node_put(np); > > > >>+ > > > >>+ if (!backlight) > > > >>+ return ERR_PTR(-EPROBE_DEFER); > > > >>+ > > > >>+ if (!backlight->props.brightness) { > > > >>+ backlight->props.brightness = backlight->props.max_brightness; > > > >>+ DRM_DEBUG_KMS("Backlight brightness set to %d\n", > > > >>+ backlight->props.brightness); > > > >>+ } > > > >>+ > > > >>+ return backlight; > > > >>+} > > > >>+EXPORT_SYMBOL(tinydrm_of_find_backlight); > > > >>+ > > > >>+/** > > > >>+ * tinydrm_enable_backlight - Enable backlight helper > > > >>+ * @backlight: Backlight device > > > >>+ * > > > >>+ * Returns: > > > >>+ * Zero on success, negative error code on failure. > > > >>+ */ > > > >>+int tinydrm_enable_backlight(struct backlight_device *backlight) > > > >>+{ > > > >>+ unsigned int old_state; > > > >>+ int ret; > > > >>+ > > > >>+ if (!backlight) > > > >>+ return 0; > > > >>+ > > > >>+ old_state = backlight->props.state; > > > >>+ backlight->props.state &= ~BL_CORE_FBBLANK; > > > >>+ DRM_DEBUG_KMS("Backlight state: 0x%x -> 0x%x\n", old_state, > > > >>+ backlight->props.state); > > > >>+ > > > >>+ ret = backlight_update_status(backlight); > > > >>+ if (ret) > > > >>+ DRM_ERROR("Failed to enable backlight %d\n", ret); > > > >>+ > > > >>+ return ret; > > > >>+} > > > >>+EXPORT_SYMBOL(tinydrm_enable_backlight); > > > >>+ > > > >>+/** > > > >>+ * tinydrm_disable_backlight - Disable backlight helper > > > >>+ * @backlight: Backlight device > > > >>+ * > > > >>+ * Returns: > > > >>+ * Zero on success, negative error code on failure. > > > >>+ */ > > > >>+int tinydrm_disable_backlight(struct backlight_device *backlight) > > > >>+{ > > > >>+ unsigned int old_state; > > > >>+ int ret; > > > >>+ > > > >>+ if (!backlight) > > > >>+ return 0; > > > >>+ > > > >>+ old_state = backlight->props.state; > > > >>+ backlight->props.state |= BL_CORE_FBBLANK; > > > >>+ DRM_DEBUG_KMS("Backlight state: 0x%x -> 0x%x\n", old_state, > > > >>+ backlight->props.state); > > > >>+ ret = backlight_update_status(backlight); > > > >>+ if (ret) > > > >>+ DRM_ERROR("Failed to disable backlight %d\n", ret); > > > >>+ > > > >>+ return ret; > > > >>+} > > > >>+EXPORT_SYMBOL(tinydrm_disable_backlight); > > > >>diff --git a/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c > > > >>b/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c > > > >>index bd6cce0..ee8ad8c 100644 > > > >>--- a/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c > > > >>+++ b/drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c > > > >>@@ -236,100 +236,6 @@ void tinydrm_xrgb8888_to_gray8(u8 *dst, void > > > >>*vaddr, struct drm_framebuffer *fb, > > > >> } > > > >> EXPORT_SYMBOL(tinydrm_xrgb8888_to_gray8); > > > >> -/** > > > >>- * tinydrm_of_find_backlight - Find backlight device in device-tree > > > >>- * @dev: Device > > > >>- * > > > >>- * This function looks for a DT node pointed to by a property named > > > >>'backlight' > > > >>- * and uses of_find_backlight_by_node() to get the backlight device. > > > >>- * Additionally if the brightness property is zero, it is set to > > > >>- * max_brightness. > > > >>- * > > > >>- * Returns: > > > >>- * NULL if there's no backlight property. > > > >>- * Error pointer -EPROBE_DEFER if the DT node is found, but no > > > >>backlight device > > > >>- * is found. > > > >>- * If the backlight device is found, a pointer to the structure is > > > >>returned. > > > >>- */ > > > >>-struct backlight_device *tinydrm_of_find_backlight(struct device *dev) > > > >>-{ > > > >>- struct backlight_device *backlight; > > > >>- struct device_node *np; > > > >>- > > > >>- np = of_parse_phandle(dev->of_node, "backlight", 0); > > > >>- if (!np) > > > >>- return NULL; > > > >>- > > > >>- backlight = of_find_backlight_by_node(np); > > > >>- of_node_put(np); > > > >>- > > > >>- if (!backlight) > > > >>- return ERR_PTR(-EPROBE_DEFER); > > > >>- > > > >>- if (!backlight->props.brightness) { > > > >>- backlight->props.brightness = backlight->props.max_brightness; > > > >>- DRM_DEBUG_KMS("Backlight brightness set to %d\n", > > > >>- backlight->props.brightness); > > > >>- } > > > >>- > > > >>- return backlight; > > > >>-} > > > >>-EXPORT_SYMBOL(tinydrm_of_find_backlight); > > > >>- > > > >>-/** > > > >>- * tinydrm_enable_backlight - Enable backlight helper > > > >>- * @backlight: Backlight device > > > >>- * > > > >>- * Returns: > > > >>- * Zero on success, negative error code on failure. > > > >>- */ > > > >>-int tinydrm_enable_backlight(struct backlight_device *backlight) > > > >>-{ > > > >>- unsigned int old_state; > > > >>- int ret; > > > >>- > > > >>- if (!backlight) > > > >>- return 0; > > > >>- > > > >>- old_state = backlight->props.state; > > > >>- backlight->props.state &= ~BL_CORE_FBBLANK; > > > >>- DRM_DEBUG_KMS("Backlight state: 0x%x -> 0x%x\n", old_state, > > > >>- backlight->props.state); > > > >>- > > > >>- ret = backlight_update_status(backlight); > > > >>- if (ret) > > > >>- DRM_ERROR("Failed to enable backlight %d\n", ret); > > > >>- > > > >>- return ret; > > > >>-} > > > >>-EXPORT_SYMBOL(tinydrm_enable_backlight); > > > >>- > > > >>-/** > > > >>- * tinydrm_disable_backlight - Disable backlight helper > > > >>- * @backlight: Backlight device > > > >>- * > > > >>- * Returns: > > > >>- * Zero on success, negative error code on failure. > > > >>- */ > > > >>-int tinydrm_disable_backlight(struct backlight_device *backlight) > > > >>-{ > > > >>- unsigned int old_state; > > > >>- int ret; > > > >>- > > > >>- if (!backlight) > > > >>- return 0; > > > >>- > > > >>- old_state = backlight->props.state; > > > >>- backlight->props.state |= BL_CORE_FBBLANK; > > > >>- DRM_DEBUG_KMS("Backlight state: 0x%x -> 0x%x\n", old_state, > > > >>- backlight->props.state); > > > >>- ret = backlight_update_status(backlight); > > > >>- if (ret) > > > >>- DRM_ERROR("Failed to disable backlight %d\n", ret); > > > >>- > > > >>- return ret; > > > >>-} > > > >>-EXPORT_SYMBOL(tinydrm_disable_backlight); > > > >> #if IS_ENABLED(CONFIG_SPI) > > > >> diff --git a/drivers/gpu/drm/tinydrm/mi0283qt.c > > > >>b/drivers/gpu/drm/tinydrm/mi0283qt.c > > > >>index 7e5bb7d..c161d45 100644 > > > >>--- a/drivers/gpu/drm/tinydrm/mi0283qt.c > > > >>+++ b/drivers/gpu/drm/tinydrm/mi0283qt.c > > > >>@@ -12,6 +12,7 @@ > > > >> #include <drm/tinydrm/ili9341.h> > > > >> #include <drm/tinydrm/mipi-dbi.h> > > > >> #include <drm/tinydrm/tinydrm-helpers.h> > > > >>+#include <drm/tinydrm/tinydrm-backlight.h> > > > >> #include <linux/delay.h> > > > >> #include <linux/gpio/consumer.h> > > > >> #include <linux/module.h> > > > >>diff --git a/drivers/gpu/drm/tinydrm/mipi-dbi.c > > > >>b/drivers/gpu/drm/tinydrm/mipi-dbi.c > > > >>index 2caeabc..dc84f26 100644 > > > >>--- a/drivers/gpu/drm/tinydrm/mipi-dbi.c > > > >>+++ b/drivers/gpu/drm/tinydrm/mipi-dbi.c > > > >>@@ -11,6 +11,7 @@ > > > >> #include <drm/tinydrm/mipi-dbi.h> > > > >> #include <drm/tinydrm/tinydrm-helpers.h> > > > >>+#include <drm/tinydrm/tinydrm-backlight.h> > > > >> #include <linux/debugfs.h> > > > >> #include <linux/dma-buf.h> > > > >> #include <linux/gpio/consumer.h> > > > >>diff --git a/include/drm/tinydrm/tinydrm-backlight.h > > > >>b/include/drm/tinydrm/tinydrm-backlight.h > > > >>new file mode 100644 > > > >>index 0000000..6a7b6d5 > > > >>--- /dev/null > > > >>+++ b/include/drm/tinydrm/tinydrm-backlight.h > > > >>@@ -0,0 +1,18 @@ > > > >>+/* > > > >>+ * Copyright (C) 2016 Noralf Trønnes > > > >>+ * > > > >>+ * This program is free software; you can redistribute it and/or modify > > > >>+ * it under the terms of the GNU General Public License as published by > > > >>+ * the Free Software Foundation; either version 2 of the License, or > > > >>+ * (at your option) any later version. > > > >>+ */ > > > >>+ > > > >>+#ifndef __LINUX_TINYDRM_BACKLIGHT_H > > > >>+#define __LINUX_TINYDRM_BACKLIGHT_H > > > >>+ > > > >>+struct backlight_device; > > > >>+struct backlight_device *tinydrm_of_find_backlight(struct device *dev); > > > >>+int tinydrm_enable_backlight(struct backlight_device *backlight); > > > >>+int tinydrm_disable_backlight(struct backlight_device *backlight); > > > >>+ > > > >>+#endif /* __LINUX_TINYDRM_BACKLIGHT_H */ > > > > > > > >_______________________________________________ > > > >dri-devel mailing list > > > >dri-devel@xxxxxxxxxxxxxxxxxxxxx > > > >https://lists.freedesktop.org/mailman/listinfo/dri-devel > > > > > > > > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
