> -----Original Message-----
> From: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> Sent: 2023年12月5日 21:19
> To: Keith Zhao <keith.zhao@xxxxxxxxxxxxxxxx>
> Cc: devicetree@xxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; linux-riscv@xxxxxxxxxxxxxxxxxxx;
> aou@xxxxxxxxxxxxxxxxx; suijingfeng@xxxxxxxxxxx; tzimmermann@xxxxxxx;
> paul.walmsley@xxxxxxxxxx; mripard@xxxxxxxxxx; Xingyu Wu
> <xingyu.wu@xxxxxxxxxxxxxxxx>; Jack Zhu <jack.zhu@xxxxxxxxxxxxxxxx>;
> palmer@xxxxxxxxxxx; krzysztof.kozlowski+dt@xxxxxxxxxx; William Qiu
> <william.qiu@xxxxxxxxxxxxxxxx>; Shengyang Chen
> <shengyang.chen@xxxxxxxxxxxxxxxx>; Changhuang Liang
> <changhuang.liang@xxxxxxxxxxxxxxxx>
> Subject: Re: [v3 6/6] drm/vs: simple encoder
>
> On Tue, 5 Dec 2023 at 15:14, Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> wrote:
> >
> > On Mon, 4 Dec 2023 at 14:33, Keith Zhao <keith.zhao@xxxxxxxxxxxxxxxx>
> wrote:
> > >
> > > add simple encoder for dsi bridge
> >
> > This doesn't look like a proper commit message.
> >
> > >
> > > Signed-off-by: Keith Zhao <keith.zhao@xxxxxxxxxxxxxxxx>
> > > ---
> > > drivers/gpu/drm/verisilicon/Makefile | 4 +-
> > > drivers/gpu/drm/verisilicon/vs_drv.c | 2 +
> > > drivers/gpu/drm/verisilicon/vs_simple_enc.c | 195
> > > ++++++++++++++++++++ drivers/gpu/drm/verisilicon/vs_simple_enc.h |
> > > 23 +++
> > > 4 files changed, 223 insertions(+), 1 deletion(-) create mode
> > > 100644 drivers/gpu/drm/verisilicon/vs_simple_enc.c
> > > create mode 100644 drivers/gpu/drm/verisilicon/vs_simple_enc.h
> > >
> > > diff --git a/drivers/gpu/drm/verisilicon/Makefile
> > > b/drivers/gpu/drm/verisilicon/Makefile
> > > index 71fadafcee13..cd5d0a90bcfe 100644
> > > --- a/drivers/gpu/drm/verisilicon/Makefile
> > > +++ b/drivers/gpu/drm/verisilicon/Makefile
> > > @@ -5,6 +5,8 @@ vs_drm-objs := vs_dc_hw.o \
> > > vs_crtc.o \
> > > vs_drv.o \
> > > vs_modeset.o \
> > > - vs_plane.o
> > > + vs_plane.o \
> > > + vs_simple_enc.o
> > > +
> > > vs_drm-$(CONFIG_DRM_VERISILICON_STARFIVE_HDMI) +=
> starfive_hdmi.o
> > > obj-$(CONFIG_DRM_VERISILICON) += vs_drm.o diff --git
> > > a/drivers/gpu/drm/verisilicon/vs_drv.c
> > > b/drivers/gpu/drm/verisilicon/vs_drv.c
> > > index d7e5199fe293..946f137ab124 100644
> > > --- a/drivers/gpu/drm/verisilicon/vs_drv.c
> > > +++ b/drivers/gpu/drm/verisilicon/vs_drv.c
> > > @@ -23,6 +23,7 @@
> > > #include "vs_drv.h"
> > > #include "vs_modeset.h"
> > > #include "vs_dc.h"
> > > +#include "vs_simple_enc.h"
> > >
> > > #define DRV_NAME "verisilicon"
> > > #define DRV_DESC "Verisilicon DRM driver"
> > > @@ -217,6 +218,7 @@ static struct platform_driver *drm_sub_drivers[]
> > > = { #ifdef CONFIG_DRM_VERISILICON_STARFIVE_HDMI
> > > &starfive_hdmi_driver,
> > > #endif
> > > + &simple_encoder_driver,
> > > };
> > >
> > > static struct component_match *vs_drm_match_add(struct device *dev)
> > > diff --git a/drivers/gpu/drm/verisilicon/vs_simple_enc.c
> > > b/drivers/gpu/drm/verisilicon/vs_simple_enc.c
> > > new file mode 100644
> > > index 000000000000..c5a8d82bc469
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/verisilicon/vs_simple_enc.c
> > > @@ -0,0 +1,195 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * Copyright (C) 2020 VeriSilicon Holdings Co., Ltd.
> > > + */
> > > +#include <linux/component.h>
> > > +#include <linux/of_device.h>
> > > +#include <linux/module.h>
> > > +
> > > +#include <drm/drm_atomic_helper.h>
> > > +#include <drm/drm_bridge.h>
> > > +#include <drm/drm_crtc_helper.h>
> > > +#include <drm/drm_of.h>
> > > +#include <linux/regmap.h>
> > > +#include <linux/media-bus-format.h> #include <linux/mfd/syscon.h>
> > > +
> > > +#include "vs_crtc.h"
> > > +#include "vs_simple_enc.h"
> > > +
> > > +static const struct simple_encoder_priv dsi_priv = {
> >
> > Please use proper prefix for all the struct and function names.
> > vs_simple_encoder sounds better. Or vs_dsi_encoder.
> >
> > > + .encoder_type = DRM_MODE_ENCODER_DSI };
> > > +
> > > +static inline struct simple_encoder *to_simple_encoder(struct
> > > +drm_encoder *enc) {
> > > + return container_of(enc, struct simple_encoder, encoder); }
> > > +
> > > +static int encoder_parse_dt(struct device *dev) {
> > > + struct simple_encoder *simple = dev_get_drvdata(dev);
> > > + unsigned int args[2];
> > > +
> > > + simple->dss_regmap =
> syscon_regmap_lookup_by_phandle_args(dev->of_node,
> > > +
> "starfive,syscon",
> > > +
> 2,
> > > + args);
> > > +
> > > + if (IS_ERR(simple->dss_regmap)) {
> > > + return dev_err_probe(dev,
> PTR_ERR(simple->dss_regmap),
> > > + "getting the regmap
> failed\n");
> > > + }
> > > +
> > > + simple->offset = args[0];
> > > + simple->mask = args[1];
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +void encoder_atomic_enable(struct drm_encoder *encoder,
> > > + struct drm_atomic_state *state) {
> > > + struct simple_encoder *simple = to_simple_encoder(encoder);
> > > +
> > > + regmap_update_bits(simple->dss_regmap, simple->offset,
> simple->mask,
> > > + simple->mask); }
> > > +
> > > +int encoder_atomic_check(struct drm_encoder *encoder,
> > > + struct drm_crtc_state *crtc_state,
> > > + struct drm_connector_state *conn_state) {
> > > + struct vs_crtc_state *vs_crtc_state =
> to_vs_crtc_state(crtc_state);
> > > + struct drm_connector *connector = conn_state->connector;
> > > + int ret = 0;
> > > +
> > > + struct drm_bridge *first_bridge =
> drm_bridge_chain_get_first_bridge(encoder);
> > > + struct drm_bridge_state *bridge_state = ERR_PTR(-EINVAL);
> > > +
> > > + vs_crtc_state->encoder_type = encoder->encoder_type;
> > > +
> > > + if (first_bridge && first_bridge->funcs->atomic_duplicate_state)
> > > + bridge_state =
> > > + drm_atomic_get_bridge_state(crtc_state->state, first_bridge);
> >
> > Please don't poke into others' playground. This should go into your
> > DSI bridge's atomic_check() instead.
>
> Hmm. And you can not use vs_crtc_state from your bridge. Actually this design
> makes me wonder, how does your hardware work? Is it possible to send the DSI
> commands to the panel?
>
Hi Dmitry:
1、 This fun is used to check the media bus format whether in support list , if not , this mode will be invalid,
I just used the bridge api to get the media bus format. (sync with the input bridge(connector) bus format)
2、 the bridge doesn't care the vs_crtc_state, just do their own drm_bridge_funcs ->atomic_check,
or it will be impossible to make this dsi encoder to fit dsi bridge driver.
3、 hardware work :
encoder_atomic_check get the media bus format and update it to vs_crtc_state-> output_fmt,
during the crtc_enable , it will write the output_fmt to hardware .
4、 to send dsi command to panel , It is only relevant to dsi controllers and panel driver (bridge and panel )，
It does not involve the logic associated with encoder and crtc
https://elixir.bootlin.com/linux/v6.6.30/source/drivers/gpu/drm/mxsfb/lcdif_kms.c#L457
Do the similar logic
Best wish
> >
> > > +
> > > + if (IS_ERR(bridge_state)) {
> > > + if (connector->display_info.num_bus_formats)
> > > + vs_crtc_state->output_fmt =
> connector->display_info.bus_formats[0];
> > > + else
> > > + vs_crtc_state->output_fmt =
> MEDIA_BUS_FMT_FIXED;
> > > + } else {
> > > + vs_crtc_state->output_fmt =
> bridge_state->input_bus_cfg.format;
> > > + }
> > > +
> > > + switch (vs_crtc_state->output_fmt) {
> > > + case MEDIA_BUS_FMT_FIXED:
> > > + case MEDIA_BUS_FMT_RGB565_1X16:
> > > + case MEDIA_BUS_FMT_RGB666_1X18:
> > > + case MEDIA_BUS_FMT_RGB888_1X24:
> > > + case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
> > > + case MEDIA_BUS_FMT_RGB101010_1X30:
> > > + case MEDIA_BUS_FMT_UYYVYY8_0_5X24:
> > > + case MEDIA_BUS_FMT_UYVY8_1X16:
> > > + case MEDIA_BUS_FMT_YUV8_1X24:
> > > + case MEDIA_BUS_FMT_UYYVYY10_0_5X30:
> > > + case MEDIA_BUS_FMT_UYVY10_1X20:
> > > + case MEDIA_BUS_FMT_YUV10_1X30:
> > > + ret = 0;
> > > + break;
> > > + default:
> > > + ret = -EINVAL;
> > > + break;
> > > + }
> > > +
> > > + /* If MEDIA_BUS_FMT_FIXED, set it to default value */
> > > + if (vs_crtc_state->output_fmt == MEDIA_BUS_FMT_FIXED)
> > > + vs_crtc_state->output_fmt =
> > > + MEDIA_BUS_FMT_RGB888_1X24;
> > > +
> > > + return ret;
> > > +}
> > > +
> > > +static const struct drm_encoder_helper_funcs encoder_helper_funcs = {
> > > + .atomic_check = encoder_atomic_check,
> > > + .atomic_enable = encoder_atomic_enable, };
> > > +
> > > +static int encoder_bind(struct device *dev, struct device *master,
> > > +void *data) {
> > > + struct drm_device *drm_dev = data;
> > > + struct simple_encoder *simple = dev_get_drvdata(dev);
> > > + struct drm_encoder *encoder;
> > > + struct drm_bridge *bridge;
> > > + int ret;
> > > +
> > > + encoder = &simple->encoder;
> > > +
> > > + ret = drmm_encoder_init(drm_dev, encoder, NULL,
> simple->priv->encoder_type, NULL);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + drm_encoder_helper_add(encoder, &encoder_helper_funcs);
> > > +
> > > + encoder->possible_crtcs =
> > > + drm_of_find_possible_crtcs(drm_dev,
> > > + dev->of_node);
> > > +
> > > + /* output port is port1*/
> > > + bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
> > > + if (IS_ERR(bridge))
> > > + return 0;
> > > +
> > > + return drm_bridge_attach(encoder, bridge, NULL, 0); }
> > > +
> > > +static const struct component_ops encoder_component_ops = {
> > > + .bind = encoder_bind,
> > > +};
> > > +
> > > +static const struct of_device_id simple_encoder_dt_match[] = {
> > > + { .compatible = "starfive,dsi-encoder", .data = &dsi_priv},
> > > + {},
> > > +};
> > > +MODULE_DEVICE_TABLE(of, simple_encoder_dt_match);
> > > +
> > > +static int encoder_probe(struct platform_device *pdev) {
> > > + struct device *dev = &pdev->dev;
> > > + struct simple_encoder *simple;
> > > + int ret;
> > > +
> > > + simple = devm_kzalloc(dev, sizeof(*simple), GFP_KERNEL);
> > > + if (!simple)
> > > + return -ENOMEM;
> > > +
> > > + simple->priv = of_device_get_match_data(dev);
> > > +
> > > + simple->dev = dev;
> > > +
> > > + dev_set_drvdata(dev, simple);
> > > +
> > > + ret = encoder_parse_dt(dev);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + return component_add(dev, &encoder_component_ops); }
> > > +
> > > +static int encoder_remove(struct platform_device *pdev) {
> > > + struct device *dev = &pdev->dev;
> > > +
> > > + component_del(dev, &encoder_component_ops);
> > > + dev_set_drvdata(dev, NULL);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +struct platform_driver simple_encoder_driver = {
> > > + .probe = encoder_probe,
> > > + .remove = encoder_remove,
> > > + .driver = {
> > > + .name = "vs-simple-encoder",
> > > + .of_match_table =
> of_match_ptr(simple_encoder_dt_match),
> > > + },
> > > +};
> > > +
> > > +MODULE_DESCRIPTION("Simple Encoder Driver");
> MODULE_LICENSE("GPL");
> > > diff --git a/drivers/gpu/drm/verisilicon/vs_simple_enc.h
> > > b/drivers/gpu/drm/verisilicon/vs_simple_enc.h
> > > new file mode 100644
> > > index 000000000000..fb33ca9e18d6
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/verisilicon/vs_simple_enc.h
> > > @@ -0,0 +1,23 @@
> > > +/* SPDX-License-Identifier: GPL-2.0 */
> > > +/*
> > > + * Copyright (C) 2022 VeriSilicon Holdings Co., Ltd.
> > > + */
> > > +
> > > +#ifndef __VS_SIMPLE_ENC_H_
> > > +#define __VS_SIMPLE_ENC_H_
> > > +
> > > +struct simple_encoder_priv {
> > > + unsigned char encoder_type;
> > > +};
> > > +
> > > +struct simple_encoder {
> > > + struct drm_encoder encoder;
> > > + struct device *dev;
> > > + const struct simple_encoder_priv *priv;
> > > + struct regmap *dss_regmap;
> > > + unsigned int offset;
> > > + unsigned int mask;
> > > +};
> > > +
> > > +extern struct platform_driver simple_encoder_driver; #endif /*
> > > +__VS_SIMPLE_ENC_H_ */
> > > --
> > > 2.34.1
> > >
> >
> >
> > --
> > With best wishes
> > Dmitry
>
>
>
> --
> With best wishes
> Dmitry
