Re: [PATCH v4 10/10] drm/vs: add simple dsi encoder
From: Dmitry Baryshkov
Date: Tue May 21 2024 - 11:25:29 EST
On Tue, May 21, 2024 at 06:58:17PM +0800, keith wrote:
> add encoder to match cdns dsi driver
>
> Signed-off-by: keith <keith.zhao@xxxxxxxxxxxxxxxx>
Please fix your git configuration to include your full name into the
S-o-B and Author fields.
> ---
> drivers/gpu/drm/verisilicon/Makefile | 3 +-
> drivers/gpu/drm/verisilicon/vs_drv.c | 1 +
> drivers/gpu/drm/verisilicon/vs_drv.h | 1 +
> drivers/gpu/drm/verisilicon/vs_simple_enc.c | 190 ++++++++++++++++++++
> drivers/gpu/drm/verisilicon/vs_simple_enc.h | 25 +++
> 5 files changed, 219 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 2d02b4a3a567..c35ba9bd6f81 100644
> --- a/drivers/gpu/drm/verisilicon/Makefile
> +++ b/drivers/gpu/drm/verisilicon/Makefile
> @@ -4,7 +4,8 @@ vs_drm-objs := vs_dc_hw.o \
> vs_modeset.o \
> vs_plane.o \
> vs_crtc.o \
> - vs_drv.o
> + vs_drv.o \
> + vs_simple_enc.o
>
> vs_drm-$(CONFIG_DRM_INNO_STARFIVE_HDMI) += inno_hdmi-starfive.o
> obj-$(CONFIG_DRM_VERISILICON_DC8200) += vs_drm.o
> diff --git a/drivers/gpu/drm/verisilicon/vs_drv.c b/drivers/gpu/drm/verisilicon/vs_drv.c
> index 6f04102b05b3..2748d48f2c7e 100644
> --- a/drivers/gpu/drm/verisilicon/vs_drv.c
> +++ b/drivers/gpu/drm/verisilicon/vs_drv.c
> @@ -612,6 +612,7 @@ static struct platform_driver *drm_sub_drivers[] = {
> #ifdef CONFIG_DRM_INNO_STARFIVE_HDMI
> &starfive_hdmi_driver,
> #endif
> + &simple_encoder_driver,
> };
>
> static struct component_match *vs_add_external_components(struct device *dev)
> diff --git a/drivers/gpu/drm/verisilicon/vs_drv.h b/drivers/gpu/drm/verisilicon/vs_drv.h
> index c3c08ed5f8ac..f3f0f170777d 100644
> --- a/drivers/gpu/drm/verisilicon/vs_drv.h
> +++ b/drivers/gpu/drm/verisilicon/vs_drv.h
> @@ -17,6 +17,7 @@
> #include <drm/drm_managed.h>
>
> #include "vs_dc_hw.h"
> +#include "vs_simple_enc.h"
>
> /*@pitch_alignment: buffer pitch alignment required by sub-devices.*/
> struct vs_drm_device {
> 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..d0b1755d77d2
> --- /dev/null
> +++ b/drivers/gpu/drm/verisilicon/vs_simple_enc.c
> @@ -0,0 +1,190 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020 VeriSilicon Holdings Co., Ltd.
Now it is 2024, so the copyright should probably cover the range.
> + */
> +#include <linux/component.h>
> +#include <linux/of_device.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/media-bus-format.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/platform_device.h>
> +#include <linux/of.h>
> +
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_bridge.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_of.h>
> +
> +#include "vs_crtc.h"
> +#include "vs_simple_enc.h"
> +
> +static const struct simple_encoder_priv dsi_priv = {
> + .encoder_type = DRM_MODE_ENCODER_DSI
So, is it 'simple' aka something generic or DSI? In the latter case,
please rename it accordingly.
> +};
> +
> +static inline struct vs_simple_encoder *to_simple_encoder(struct drm_encoder *enc)
> +{
> + return container_of(enc, struct vs_simple_encoder, encoder);
> +}
> +
> +static int encoder_parse_dt(struct device *dev)
> +{
> + struct vs_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];
Is the value that you've read platform dependent or use case dependent?
What is the actual value being written? Why are you using syscon for it?
> +
> + return 0;
> +}
> +
> +static void vs_encoder_atomic_enable(struct drm_encoder *encoder, struct drm_atomic_state *state)
> +{
> + struct vs_simple_encoder *simple = to_simple_encoder(encoder);
> +
> + regmap_update_bits(simple->dss_regmap, simple->offset, simple->mask, simple->mask);
A purist in me would ask to have separate mask and value to write.
> +}
Is it necessary to clear those bits when stopping the stream?
[skipped the rest]
> +
> +
> +struct platform_driver simple_encoder_driver = {
> + .probe = vs_encoder_probe,
> + .remove = vs_encoder_remove,
> + .driver = {
> + .name = "vs-simple-encoder",
> + .of_match_table = of_match_ptr(simple_encoder_dt_match),
> + },
> +};
> +
> +MODULE_DESCRIPTION("Simple Encoder Driver");
VeriSilicon DSI Encoder
> +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..73e356bfeb2c
> --- /dev/null
> +++ b/drivers/gpu/drm/verisilicon/vs_simple_enc.h
> @@ -0,0 +1,25 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2022 VeriSilicon Holdings Co., Ltd.
> + */
> +
> +#ifndef __VS_SIMPLE_ENC_H_
> +#define __VS_SIMPLE_ENC_H_
> +
> +#include <drm/drm_encoder.h>
> +
> +struct simple_encoder_priv {
> + unsigned char encoder_type;
> +};
> +
> +struct vs_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;
> +};
Is there a need for aheader for the encoder? Can you move the
definitions to the source file?
> +
> +extern struct platform_driver simple_encoder_driver;
> +#endif /* __VS_SIMPLE_ENC_H_ */
> --
> 2.27.0
>
--
With best wishes
Dmitry