[PATCH RFC v3 2/6] drm/sprd: add Unisoc's drm kms master
tang pengchuan
kevin3.tang at gmail.com
Sat Feb 22 17:06:56 UTC 2020
On Sat, Feb 22, 2020 at 5:36 AM Sam Ravnborg <sam at ravnborg.org> wrote:
> Hi Kevin.
>
> On Fri, Feb 21, 2020 at 03:48:52PM +0800, Kevin Tang wrote:
> > From: Kevin Tang <kevin.tang at unisoc.com>
> >
> > Adds drm support for the Unisoc's display subsystem.
>
> Thanks for the updated driver patch.
> Good split of patches.
> A few comments in the following.
> Please filter in the comments as some may not apply to this driver.
>
> Sam
>
> >
> > This is drm device and gem driver. This driver provides support for the
> > Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
> Hmm, hopefully we can use this without XFree86?
> Looks like the above was copied from something outdated.
>
Yes, copy from drm/Kconfig, but we have tested ok on android hwcomposer.
It is indeed copied from outdated content, need to fix it?
>
>
> > +++ b/drivers/gpu/drm/sprd/Kconfig
> > @@ -0,0 +1,14 @@
> > +config DRM_SPRD
> > + tristate "DRM Support for Unisoc SoCs Platform"
> > + depends on ARCH_SPRD
> > + depends on DRM && OF
> > + select DRM_KMS_HELPER
> > + select DRM_GEM_CMA_HELPER
> > + select DRM_KMS_CMA_HELPER
> > + select DRM_MIPI_DSI
> > + select DRM_PANEL
> > + select VIDEOMODE_HELPERS
> > + select BACKLIGHT_CLASS_DEVICE
> > + help
> > + Choose this option if you have a Unisoc chipsets.
> > + If M is selected the module will be called sprd-drm.
>
> Please check that VIDEOMODE_HELPERS is really needed.
> Please add COMPILE_TEST - so we will build this driver with
> allmodconfig/allyesconfig.
> This is how we ofthe verify refactoring work.
>
Ok, i will fix it.
>
>
> > \ No newline at end of file
> Please fix.
>
>
> > diff --git a/drivers/gpu/drm/sprd/Makefile
> b/drivers/gpu/drm/sprd/Makefile
> > new file mode 100644
> > index 0000000..63b8751
> > --- /dev/null
> > +++ b/drivers/gpu/drm/sprd/Makefile
> > @@ -0,0 +1,7 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +
> > +ccflags-y += -Iinclude/drm
> Not required - delete.
>
Ok, this can be delete, thanks for reminding.
>
> > +
> > +subdir-ccflags-y += -I$(src)
> Not required - delete.
>
This maybe can't, because our dpu subdir need it to found parent dir header
file.
> > +
> > +obj-y := sprd_drm.o
>
> > diff --git a/drivers/gpu/drm/sprd/sprd_drm.c
> b/drivers/gpu/drm/sprd/sprd_drm.c
> > new file mode 100644
> > index 0000000..7cac098
> > --- /dev/null
> > +++ b/drivers/gpu/drm/sprd/sprd_drm.c
> > @@ -0,0 +1,292 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2019 Unisoc Inc.
> > + */
> > +
> > +#include <linux/component.h>
> > +#include <linux/dma-mapping.h>
> > +#include <linux/module.h>
> > +#include <linux/mutex.h>
> > +#include <linux/of_graph.h>
> > +#include <linux/of_platform.h>
> > +
> > +#include <drm/drm_atomic_helper.h>
> > +#include <drm/drm_crtc_helper.h>
> > +#include <drm/drm_drv.h>
> > +#include <drm/drm_gem_cma_helper.h>
> > +#include <drm/drm_gem_framebuffer_helper.h>
> > +#include <drm/drm_probe_helper.h>
> > +#include <drm/drm_vblank.h>
> > +
> > +#include "sprd_drm.h"
> > +
> > +#define DRIVER_NAME "sprd"
> > +#define DRIVER_DESC "Spreadtrum SoCs' DRM Driver"
> > +#define DRIVER_DATE "20191101"
> We are in 2020 now..
>
> > +#define DRIVER_MAJOR 1
> > +#define DRIVER_MINOR 0
> > +
> > +static const struct drm_mode_config_helper_funcs
> sprd_drm_mode_config_helper = {
> > + .atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
> > +};
> > +
> > +static const struct drm_mode_config_funcs sprd_drm_mode_config_funcs = {
> > + .fb_create = drm_gem_fb_create,
> > + .atomic_check = drm_atomic_helper_check,
> > + .atomic_commit = drm_atomic_helper_commit,
> > +};
> > +
> > +static void sprd_drm_mode_config_init(struct drm_device *drm)
> > +{
> > + drm_mode_config_init(drm);
> > +
> > + drm->mode_config.min_width = 0;
> > + drm->mode_config.min_height = 0;
> > + drm->mode_config.max_width = 8192;
> > + drm->mode_config.max_height = 8192;
> > + drm->mode_config.allow_fb_modifiers = true;
> > +
> > + drm->mode_config.funcs = &sprd_drm_mode_config_funcs;
> > + drm->mode_config.helper_private = &sprd_drm_mode_config_helper;
> > +}
> > +
> > +DEFINE_DRM_GEM_CMA_FOPS(sprd_drm_fops);
> > +
> > +static struct drm_driver sprd_drm_drv = {
> > + .driver_features = DRIVER_GEM | DRIVER_MODESET |
> DRIVER_ATOMIC,
> > + .fops = &sprd_drm_fops,
> > +
> > + /* GEM Operations */
> > + DRM_GEM_CMA_VMAP_DRIVER_OPS,
> > +
> > + .name = DRIVER_NAME,
> > + .desc = DRIVER_DESC,
> > + .date = DRIVER_DATE,
> > + .major = DRIVER_MAJOR,
> > + .minor = DRIVER_MINOR,
> > +};
> > +
> > +static int sprd_drm_bind(struct device *dev)
> > +{
> > + struct drm_device *drm;
> > + struct sprd_drm *sprd;
> > + int err;
> > +
> > + drm = drm_dev_alloc(&sprd_drm_drv, dev);
> > + if (IS_ERR(drm))
> > + return PTR_ERR(drm);
> You should embed drm_device in struct sprd_drm.
> See example code in drm/drm_drv.c
>
> This is what modern drm drivers do.
>
> I *think* you can drop the component framework if you do this.
>
I have read it(drm/drm_drv.c) carefully, if drop the component framework,
the whole our drm driver maybe need to redesign, so i still want to keep
current design.
>
> > +
> > + dev_set_drvdata(dev, drm);
> > +
> > + sprd = devm_kzalloc(drm->dev, sizeof(*sprd), GFP_KERNEL);
> > + if (!sprd) {
> > + err = -ENOMEM;
> > + goto err_free_drm;
> > + }
> > + drm->dev_private = sprd;
> > +
> > + sprd_drm_mode_config_init(drm);
> > +
> > + /* bind and init sub drivers */
> > + err = component_bind_all(drm->dev, drm);
> > + if (err) {
> > + DRM_ERROR("failed to bind all component.\n");
> > + goto err_dc_cleanup;
> > + }
> When you have a drm_device - which you do here.
> Then please use drm_err() and friends for error messages.
> Please verify all uses of DRM_XXX
>
modern drm drivers need drm_xxx to replace DRM_XXX?
>
> > +
> > + /* vblank init */
> > + err = drm_vblank_init(drm, drm->mode_config.num_crtc);
> > + if (err) {
> > + DRM_ERROR("failed to initialize vblank.\n");
> > + goto err_unbind_all;
> > + }
>
>
> > + /* with irq_enabled = true, we can use the vblank feature. */
> > + drm->irq_enabled = true;
> I cannot see any irq being installed. This looks wrong.
>
Our display controller isr is been register on crtc driver(sprd_dpu.c), not
here.
>
> > +
> > + /* reset all the states of crtc/plane/encoder/connector */
> > + drm_mode_config_reset(drm);
> > +
> > + /* init kms poll for handling hpd */
> > + drm_kms_helper_poll_init(drm);
> > +
> > + err = drm_dev_register(drm, 0);
> > + if (err < 0)
> > + goto err_kms_helper_poll_fini;
> > +
> > + return 0;
> > +
> > +err_kms_helper_poll_fini:
> > + drm_kms_helper_poll_fini(drm);
> > +err_unbind_all:
> > + component_unbind_all(drm->dev, drm);
> > +err_dc_cleanup:
> > + drm_mode_config_cleanup(drm);
> > +err_free_drm:
> > + drm_dev_put(drm);
> > + return err;
> Please see the example in drm/drm_drv.c - following the example
> will simpligy error handling a bit.
> Ad you will learn not to use drm_dev_put().
>
Ok, i will fix it
>
> > +}
> > +
> > +static void sprd_drm_unbind(struct device *dev)
> > +{
> > + drm_put_dev(dev_get_drvdata(dev));
> > +}
> > +
> > +static const struct component_master_ops drm_component_ops = {
> > + .bind = sprd_drm_bind,
> > + .unbind = sprd_drm_unbind,
> > +};
> > +
> > +static int compare_of(struct device *dev, void *data)
> > +{
> > + struct device_node *np = data;
> > +
> > + DRM_DEBUG("compare %s\n", np->full_name);
> Leftover debugging that can be dropped?
>
Ok, i will drop useless debug log.
>
> > +
> > + return dev->of_node == np;
> > +}
> > +
> > +static int sprd_drm_component_probe(struct device *dev,
> > + const struct component_master_ops *m_ops)
> > +{
> > + struct device_node *ep, *port, *remote;
> > + struct component_match *match = NULL;
> > + int i;
> > +
> > + if (!dev->of_node)
> > + return -EINVAL;
> > +
> > + /*
> > + * Bind the crtc's ports first, so that
> drm_of_find_possible_crtcs()
> > + * called from encoder's .bind callbacks works as expected
> > + */
> > + for (i = 0; ; i++) {
> > + port = of_parse_phandle(dev->of_node, "ports", i);
> > + if (!port)
> > + break;
> > +
> > + if (!of_device_is_available(port->parent)) {
> > + of_node_put(port);
> > + continue;
> > + }
> > +
> > + component_match_add(dev, &match, compare_of, port->parent);
> > + of_node_put(port);
> > + }
> > +
> > + if (i == 0) {
> > + dev_err(dev, "missing 'ports' property\n");
> > + return -ENODEV;
> > + }
> > +
> > + if (!match) {
> > + dev_err(dev, "no available port\n");
> > + return -ENODEV;
> > + }
> > +
> > + /*
> > + * For bound crtcs, bind the encoders attached to their remote
> endpoint
> > + */
> > + for (i = 0; ; i++) {
> > + port = of_parse_phandle(dev->of_node, "ports", i);
> > + if (!port)
> > + break;
> > +
> > + if (!of_device_is_available(port->parent)) {
> > + of_node_put(port);
> > + continue;
> > + }
> > +
> > + for_each_child_of_node(port, ep) {
> > + remote = of_graph_get_remote_port_parent(ep);
> > + if (!remote || !of_device_is_available(remote)) {
> > + of_node_put(remote);
> > + continue;
> > + } else if
> (!of_device_is_available(remote->parent)) {
> > + dev_warn(dev, "parent device of %s is not
> available\n",
> > + remote->full_name);
> > + of_node_put(remote);
> > + continue;
> > + }
> > +
> > + component_match_add(dev, &match, compare_of,
> remote);
> > + of_node_put(remote);
> > + }
> > + of_node_put(port);
> > + }
> > +
> > + return component_master_add_with_match(dev, m_ops, match);
> > +}
> > +
> > +static int sprd_drm_probe(struct platform_device *pdev)
> > +{
> > + int ret;
> > +
> > + ret = dma_set_mask_and_coherent(&pdev->dev, ~0);
> I do not thing ~0 is always the right mask.
> Please verify.
>
It's right mask for us.
>
> > + if (ret) {
> > + DRM_ERROR("dma_set_mask_and_coherent failed (%d)\n", ret);
> > + return ret;
> > + }
> > +
> > + return sprd_drm_component_probe(&pdev->dev, &drm_component_ops);
> > +}
> > +
> > +static int sprd_drm_remove(struct platform_device *pdev)
> > +{
> > + component_master_del(&pdev->dev, &drm_component_ops);
> > + return 0;
> > +}
> > +
> > +static void sprd_drm_shutdown(struct platform_device *pdev)
> > +{
> > + struct drm_device *drm = platform_get_drvdata(pdev);
> > +
> > + if (!drm) {
> > + DRM_WARN("drm device is not available, no shutdown\n");
> > + return;
> > + }
> > +
> > + drm_atomic_helper_shutdown(drm);
> > +}
> > +
> > +static const struct of_device_id drm_match_table[] = {
> > + { .compatible = "sprd,display-subsystem", },
> > + {},
>
> Sometimes we use { /* sentinel */ },
> here.
>
Ok, i will fix it
>
> > +};
> > +MODULE_DEVICE_TABLE(of, drm_match_table);
> > +
> > +static struct platform_driver sprd_drm_driver = {
> > + .probe = sprd_drm_probe,
> > + .remove = sprd_drm_remove,
> > + .shutdown = sprd_drm_shutdown,
> > + .driver = {
> > + .name = "sprd-drm-drv",
> > + .of_match_table = drm_match_table,
> > + },
> > +};
> > +
> > +static struct platform_driver *sprd_drm_drivers[] = {
> > + &sprd_drm_driver,
> > +};
> > +
> > +static int __init sprd_drm_init(void)
> > +{
> > + int ret;
> > +
> > + ret = platform_register_drivers(sprd_drm_drivers,
> > + ARRAY_SIZE(sprd_drm_drivers));
> > + return ret;
> > +}
> > +
> > +static void __exit sprd_drm_exit(void)
> > +{
> > + platform_unregister_drivers(sprd_drm_drivers,
> > + ARRAY_SIZE(sprd_drm_drivers));
> > +}
> > +
> > +module_init(sprd_drm_init);
> > +module_exit(sprd_drm_exit);
> > +
> > +MODULE_AUTHOR("Leon He <leon.he at unisoc.com>");
> > +MODULE_AUTHOR("Kevin Tang <kevin.tang at unisoc.com>");
> > +MODULE_DESCRIPTION("Unisoc DRM KMS Master Driver");
> > +MODULE_LICENSE("GPL v2");
> > diff --git a/drivers/gpu/drm/sprd/sprd_drm.h
> b/drivers/gpu/drm/sprd/sprd_drm.h
> > new file mode 100644
> > index 0000000..137cb27
> > --- /dev/null
> > +++ b/drivers/gpu/drm/sprd/sprd_drm.h
> > @@ -0,0 +1,16 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Copyright (C) 2019 Unisoc Inc.
> > + */
> > +
> > +#ifndef _SPRD_DRM_H_
> > +#define _SPRD_DRM_H_
> > +
> > +#include <drm/drm_atomic.h>
> > +#include <drm/drm_print.h>
> > +
> > +struct sprd_drm {
> > + struct drm_device *drm;
> > +};
> > +
> > +#endif /* _SPRD_DRM_H_ */
> > --
> > 2.7.4
> >
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
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