Re: [PATCH RFC v3 2/6] drm/sprd: add Unisoc's drm kms master

Emil Velikov
2020-02-24T16:43:31Z

Hi all,

On Fri, 21 Feb 2020 at 11:15, Kevin Tang <kevin3.tang@gmail.com> wrote:
>
> From: Kevin Tang <kevin.tang@unisoc.com>
>
> Adds drm support for the Unisoc's display subsystem.
>
> This is drm device and gem driver. This driver provides support for the
> Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
>
> Cc: Orson Zhai <orsonzhai@gmail.com>
> Cc: Baolin Wang <baolin.wang@linaro.org>
> Cc: Chunyan Zhang <zhang.lyra@gmail.com>
> Signed-off-by: Kevin Tang <kevin.tang@unisoc.com>
> ---
> drivers/gpu/drm/Kconfig | 2 +
> drivers/gpu/drm/Makefile | 1 +
> drivers/gpu/drm/sprd/Kconfig | 14 ++
> drivers/gpu/drm/sprd/Makefile | 7 +
> drivers/gpu/drm/sprd/sprd_drm.c | 292 ++++++++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/sprd/sprd_drm.h | 16 +++
> 6 files changed, 332 insertions(+)
> create mode 100644 drivers/gpu/drm/sprd/Kconfig
> create mode 100644 drivers/gpu/drm/sprd/Makefile
> create mode 100644 drivers/gpu/drm/sprd/sprd_drm.c
> create mode 100644 drivers/gpu/drm/sprd/sprd_drm.h
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index bfdadc3..cead12c 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -387,6 +387,8 @@ source "drivers/gpu/drm/aspeed/Kconfig"
>
> source "drivers/gpu/drm/mcde/Kconfig"
>
> +source "drivers/gpu/drm/sprd/Kconfig"
> +
> # Keep legacy drivers last
>
> menuconfig DRM_LEGACY
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 9f1c7c4..85ca211 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -122,3 +122,4 @@ obj-$(CONFIG_DRM_LIMA) += lima/
> obj-$(CONFIG_DRM_PANFROST) += panfrost/
> obj-$(CONFIG_DRM_ASPEED_GFX) += aspeed/
> obj-$(CONFIG_DRM_MCDE) += mcde/
> +obj-$(CONFIG_DRM_SPRD) += sprd/
> diff --git a/drivers/gpu/drm/sprd/Kconfig b/drivers/gpu/drm/sprd/Kconfig
> new file mode 100644
> index 0000000..79f286b
> --- /dev/null
> +++ b/drivers/gpu/drm/sprd/Kconfig
> @@ -0,0 +1,14 @@
> +config DRM_SPRD
> + tristate "DRM Support for Unisoc SoCs Platform"
> + depends on ARCH_SPRD
> + depends on DRM && OF
> + select DRM_KMS_HELPER
> + select DRM_GEM_CMA_HELPER
> + select DRM_KMS_CMA_HELPER
> + select DRM_MIPI_DSI
> + select DRM_PANEL
> + select VIDEOMODE_HELPERS
> + select BACKLIGHT_CLASS_DEVICE
> + help
> + Choose this option if you have a Unisoc chipsets.
> + If M is selected the module will be called sprd-drm.
> \ No newline at end of file
> diff --git a/drivers/gpu/drm/sprd/Makefile b/drivers/gpu/drm/sprd/Makefile
> new file mode 100644
> index 0000000..63b8751
> --- /dev/null
> +++ b/drivers/gpu/drm/sprd/Makefile
> @@ -0,0 +1,7 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +ccflags-y += -Iinclude/drm
> +
> +subdir-ccflags-y += -I$(src)
> +
> +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"
> +#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);
> +
> + 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;
> + }
> +
> + /* 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;
> +
> + /* 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;
> +}
> +
> +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);
> +
> + 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);

This whole function is effectively a copy of drm_of_component_probe().
Reuse that instead.

With that + comments from Sam addressed this patch is:
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

-Emil