Re: [PATCH v3 2/2] drm: bridge: Add Chipone ICN6211 MIPI-DSI to RGB bridge

Robert Foss
2021-02-15T12:17:48Z

Hey Jagan,

Thanks for submitting this driver, it looks really nice, but
checkpatch.pl has some minor issues with it. Again I'd suggest
deferring to the convertor->converter spelling change even though both
seem to be perfectly valid English.

With the below fixed, feel free to add my r-b.
Reviewed-by: Robert Foss <robert.foss@linaro.org>

On Sun, 14 Feb 2021 at 18:55, Jagan Teki <jagan@amarulasolutions.com> wrote:
>
> ICN6211 is MIPI-DSI to RGB Convertor bridge from Chipone.

WARNING: 'Convertor' may be misspelled - perhaps 'Converter'?
#6:
ICN6211 is MIPI-DSI to RGB Convertor bridge from Chipone.
^^^^^^^^^

>
> It has a flexible configuration of MIPI DSI signal input and
> produce RGB565, RGB666, RGB888 output format.
>
> Add bridge driver for it.

Currently this driver only supports MIPI_DSI_FMT_RGB888, maybe this
should be noted in the commit msg.

>
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
> Changes for v3:
> - updated the driver to inline with new drm bridge style
>
> MAINTAINERS | 6 +
> drivers/gpu/drm/bridge/Kconfig | 11 ++
> drivers/gpu/drm/bridge/Makefile | 1 +
> drivers/gpu/drm/bridge/chipone-icn6211.c | 222 +++++++++++++++++++++++
> 4 files changed, 240 insertions(+)
> create mode 100644 drivers/gpu/drm/bridge/chipone-icn6211.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 9d241b832aae..4f1084aae50d 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5529,6 +5529,12 @@ S: Maintained
> F: Documentation/devicetree/bindings/display/panel/boe,himax8279d.yaml
> F: drivers/gpu/drm/panel/panel-boe-himax8279d.c
>
> +DRM DRIVER FOR CHIPONE ICN6211 MIPI-DSI to RGB CONVERTOR BRIDGE

WARNING: 'CONVERTOR' may be misspelled - perhaps 'CONVERTER'?
#30: FILE: MAINTAINERS:5533:
+DRM DRIVER FOR CHIPONE ICN6211 MIPI-DSI to RGB CONVERTOR BRIDGE
^^^^^^^^^

> +M: Jagan Teki <jagan@amarulasolutions.com>
> +S: Maintained
> +F: drivers/gpu/drm/bridge/chipone-icn6211.c
> +F: Documentation/devicetree/bindings/display/bridge/chipone,icn6211.yaml

WARNING: Misordered MAINTAINERS entry - list file patterns in alphabetic order
#34: FILE: MAINTAINERS:5537:
+F: drivers/gpu/drm/bridge/chipone-icn6211.c
+F: Documentation/devicetree/bindings/display/bridge/chipone,icn6211.yaml

> +
> DRM DRIVER FOR FARADAY TVE200 TV ENCODER
> M: Linus Walleij <linus.walleij@linaro.org>
> S: Maintained
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index e4110d6ca7b3..49d1565b7f25 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -27,6 +27,17 @@ config DRM_CDNS_DSI
> Support Cadence DPI to DSI bridge. This is an internal
> bridge and is meant to be directly embedded in a SoC.
>
> +config DRM_CHIPONE_ICN6211
> + tristate "Chipone ICN6211 MIPI-DSI/RGB Convertor bridge"

WARNING: 'Convertor' may be misspelled - perhaps 'Converter'?
#48: FILE: drivers/gpu/drm/bridge/Kconfig:31:
+ tristate "Chipone ICN6211 MIPI-DSI/RGB Convertor bridge"
^^^^^^^^^

> + depends on OF
> + select DRM_MIPI_DSI
> + select DRM_PANEL_BRIDGE
> + help
> + ICN6211 is MIPI-DSI/RGB Convertor bridge from chipone.

WARNING: 'Convertor' may be misspelled - perhaps 'Converter'?
#53: FILE: drivers/gpu/drm/bridge/Kconfig:36:
+ ICN6211 is MIPI-DSI/RGB Convertor bridge from chipone.
^^^^^^^^^

> +
> + It has a flexible configuration of MIPI DSI signal input
> + and produce RGB565, RGB666, RGB888 output format.
> +

WARNING: please write a paragraph that describes the config symbol fully
#47: FILE: drivers/gpu/drm/bridge/Kconfig:30:
+config DRM_CHIPONE_ICN6211

> config DRM_CHRONTEL_CH7033
> tristate "Chrontel CH7033 Video Encoder"
> depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index 86e7acc76f8d..3eb84b638988 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -1,5 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
> +obj-$(CONFIG_DRM_CHIPONE_ICN6211) += chipone-icn6211.o
> obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o
> obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o
> obj-$(CONFIG_DRM_LONTIUM_LT9611) += lontium-lt9611.o
> diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c
> new file mode 100644
> index 000000000000..3f478f21a4a5
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c
> @@ -0,0 +1,222 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2020 Amarula Solutions(India)

2020-2021?

> + * Author: Jagan Teki <jagan@amarulasolutions.com>
> + */
> +
> +#include <drm/drm_of.h>
> +#include <drm/drm_print.h>
> +#include <drm/drm_mipi_dsi.h>
> +
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +
> +#include <video/mipi_display.h>
> +
> +struct chipone {
> + struct device *dev;
> + struct drm_bridge bridge;
> + struct drm_bridge *panel_bridge;
> + struct gpio_desc *reset_gpio;
> +};
> +
> +static inline struct chipone *bridge_to_chipone(struct drm_bridge *bridge)
> +{
> + return container_of(bridge, struct chipone, bridge);
> +}
> +
> +static struct drm_display_mode *bridge_to_mode(struct drm_bridge *bridge)
> +{
> + return &bridge->encoder->crtc->state->adjusted_mode;
> +}
> +
> +static void chipone_post_disable(struct drm_bridge *bridge)
> +{
> + struct chipone *icn = bridge_to_chipone(bridge);
> +
> + gpiod_set_value(icn->reset_gpio, 0);
> +
> + msleep(50);
> +}
> +
> +static inline int chipone_dsi_write(struct chipone *icn, const void *seq,
> + size_t len)
> +{
> + struct mipi_dsi_device *dsi = to_mipi_dsi_device(icn->dev);
> +
> + return mipi_dsi_generic_write(dsi, seq, len);
> +}
> +
> +#define CHIPONE_DSI(icn, seq...) \
> + { \
> + const u8 d[] = { seq }; \
> + chipone_dsi_write(icn, d, ARRAY_SIZE(d)); \
> + }
> +
> +static void chipone_enable(struct drm_bridge *bridge)
> +{
> + struct chipone *icn = bridge_to_chipone(bridge);
> + struct drm_display_mode *mode = bridge_to_mode(bridge);
> +
> + CHIPONE_DSI(icn, 0x7A, 0xC1);
> +
> + /* lower 8 bits of hdisplay */
> + CHIPONE_DSI(icn, 0x20, mode->hdisplay & 0xff);
> +
> + /* lower 8 bits of vdisplay */
> + CHIPONE_DSI(icn, 0x21, mode->vdisplay & 0xff);
> +
> + /**
> + * lsb nibble: 2nd nibble of hdisplay
> + * msb nibble: 2nd nibble of vdisplay
> + */
> + CHIPONE_DSI(icn, 0x22, (((mode->hdisplay >> 8) & 0xf) |
> + (((mode->vdisplay >> 8) & 0xf) << 4)));
> +
> + /* HFP */
> + CHIPONE_DSI(icn, 0x23, mode->hsync_start - mode->hdisplay);
> +
> + /* HSYNC */
> + CHIPONE_DSI(icn, 0x24, mode->hsync_end - mode->hsync_start);
> +
> + /* HBP */
> + CHIPONE_DSI(icn, 0x25, mode->htotal - mode->hsync_end);
> +
> + CHIPONE_DSI(icn, 0x26, 0x00);
> +
> + /* VFP */
> + CHIPONE_DSI(icn, 0x27, mode->vsync_start - mode->vdisplay);
> +
> + /* VSYNC */
> + CHIPONE_DSI(icn, 0x28, mode->vsync_end - mode->vsync_start);
> +
> + /* VBP */
> + CHIPONE_DSI(icn, 0x29, mode->vtotal - mode->vsync_end);
> +
> + /* dsi specific sequence */
> + CHIPONE_DSI(icn, MIPI_DCS_SET_TEAR_OFF, 0x80);
> + CHIPONE_DSI(icn, MIPI_DCS_SET_ADDRESS_MODE, 0x28);
> + CHIPONE_DSI(icn, 0xB5, 0xA0);
> + CHIPONE_DSI(icn, 0x5C, 0xFF);
> + CHIPONE_DSI(icn, MIPI_DCS_SET_COLUMN_ADDRESS, 0x01);
> + CHIPONE_DSI(icn, MIPI_DCS_GET_POWER_SAVE, 0x92);
> + CHIPONE_DSI(icn, 0x6B, 0x71);
> + CHIPONE_DSI(icn, 0x69, 0x2B);
> + CHIPONE_DSI(icn, MIPI_DCS_ENTER_SLEEP_MODE, 0x40);
> + CHIPONE_DSI(icn, MIPI_DCS_EXIT_SLEEP_MODE, 0x98);
> +
> + /* icn6211 specific sequence */
> + CHIPONE_DSI(icn, 0xB6, 0x20);
> + CHIPONE_DSI(icn, 0x51, 0x20);
> + CHIPONE_DSI(icn, 0x09, 0x10);
> +
> + msleep(120);
> +}
> +
> +static void chipone_pre_enable(struct drm_bridge *bridge)
> +{
> + struct chipone *icn = bridge_to_chipone(bridge);
> +
> + gpiod_set_value(icn->reset_gpio, 1);
> + msleep(20);
> +
> + gpiod_set_value(icn->reset_gpio, 0);
> + msleep(20);
> +
> + gpiod_set_value(icn->reset_gpio, 1);
> + msleep(50);
> +}
> +
> +static int chipone_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags)
> +{
> + struct chipone *icn = bridge_to_chipone(bridge);
> +
> + return drm_bridge_attach(bridge->encoder, icn->panel_bridge, bridge, flags);
> +}
> +
> +static const struct drm_bridge_funcs chipone_bridge_funcs = {
> + .post_disable = chipone_post_disable,
> + .enable = chipone_enable,
> + .pre_enable = chipone_pre_enable,
> + .attach = chipone_attach,
> +};
> +
> +static int chipone_probe(struct mipi_dsi_device *dsi)
> +{
> + struct device *dev = &dsi->dev;
> + struct drm_panel *panel;
> + struct chipone *icn;
> + int ret;
> +
> + icn = devm_kzalloc(dev, sizeof(struct chipone), GFP_KERNEL);
> + if (!icn)
> + return -ENOMEM;
> +
> + mipi_dsi_set_drvdata(dsi, icn);
> + icn->dev = dev;
> +
> + dsi->mode_flags = MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
> + dsi->format = MIPI_DSI_FMT_RGB888;
> + dsi->lanes = 4;
> +
> + icn->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> + if (IS_ERR(icn->reset_gpio)) {
> + DRM_DEV_ERROR(dev, "failed to get reset GPIO\n");
> + return PTR_ERR(icn->reset_gpio);
> + }
> +
> + ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL);
> + if (ret)
> + return ret;
> +
> + icn->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
> + if (IS_ERR(icn->panel_bridge))
> + return PTR_ERR(icn->panel_bridge);
> +
> + icn->bridge.funcs = &chipone_bridge_funcs;
> + icn->bridge.type = DRM_MODE_CONNECTOR_DPI;
> + icn->bridge.of_node = dev->of_node;
> +
> + drm_bridge_add(&icn->bridge);
> +
> + ret = mipi_dsi_attach(dsi);
> + if (ret < 0) {
> + drm_bridge_remove(&icn->bridge);
> + dev_err(dev, "failed to attach dsi\n");
> + }
> +
> + return ret;
> +}
> +
> +static int chipone_remove(struct mipi_dsi_device *dsi)
> +{
> + struct chipone *icn = mipi_dsi_get_drvdata(dsi);
> +
> + mipi_dsi_detach(dsi);
> + drm_bridge_remove(&icn->bridge);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id chipone_of_match[] = {
> + { .compatible = "chipone,icn6211", },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, chipone_of_match);
> +
> +static struct mipi_dsi_driver chipone_driver = {
> + .probe = chipone_probe,
> + .remove = chipone_remove,
> + .driver = {
> + .name = "chipone-icn6211",
> + .owner = THIS_MODULE,
> + .of_match_table = chipone_of_match,
> + },
> +};
> +module_mipi_dsi_driver(chipone_driver);
> +
> +MODULE_AUTHOR("Jagan Teki <jagan@amarulasolutions.com>");
> +MODULE_DESCRIPTION("Chipone ICN6211 MIPI-DSI to RGB Convertor Bridge");

WARNING: 'Convertor' may be misspelled - perhaps 'Converter'?
#298: FILE: drivers/gpu/drm/bridge/chipone-icn6211.c:221:
+MODULE_DESCRIPTION("Chipone ICN6211 MIPI-DSI to RGB Convertor Bridge");
^^^^^^^^^

> +MODULE_LICENSE("GPL");
> --
> 2.25.1
>