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[0/4] Add simple-dbi tinydrm driver

Message ID 20210802063538.75583-1-icenowy@sipeed.com
Headers show
Series Add simple-dbi tinydrm driver | expand

Message

Icenowy Zheng Aug. 2, 2021, 6:35 a.m. UTC 
This patchset adds a tinydrm driver called simple-dbi, which is a driver
that utilizes only standardized commands in MIPI DCS to activate a MIPI
DBI panel that requires no extra configuration, usually because the
configuration is pre-programmed into the OTP of the LCD controller.

Icenowy Zheng (4):
  dt-bindings: vendor-prefixes: add Zhishengxin
  dt-bindings: display: add binding for simple-dbi panels
  drm/tiny: add simple-dbi driver
  MAINTAINERS: add simple-dbi driver

 .../bindings/display/simple-dbi.yaml          |  72 ++++++
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 MAINTAINERS                                   |   7 +
 drivers/gpu/drm/tiny/Kconfig                  |  12 +
 drivers/gpu/drm/tiny/Makefile                 |   1 +
 drivers/gpu/drm/tiny/simple-dbi.c             | 244 ++++++++++++++++++
 6 files changed, 338 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/simple-dbi.yaml
 create mode 100644 drivers/gpu/drm/tiny/simple-dbi.c

Comments

Thomas Zimmermann Aug. 3, 2021, 8:21 a.m. UTC | #1 
Hi

Am 03.08.21 um 03:25 schrieb Icenowy Zheng:
> 在 2021-08-02星期一的 17:08 +0200，Thomas Zimmermann写道：

>> Hi

>>

>> Am 02.08.21 um 08:35 schrieb Icenowy Zheng:

>>> Add a driver for generic MIPI DBI panels initialized with MIPI DCS

>>> commands.

>>>

>>> Currently a ST7789V-based panel is added to it. This panel has its

>>> configuration pre-programmed into the controller, so no vendor-

>>> specific

>>> configuration is needed.

>>>

>>> Signed-off-by: Icenowy Zheng <icenowy@sipeed.com>

>>> ---

>>>    drivers/gpu/drm/tiny/Kconfig      |  12 ++

>>>    drivers/gpu/drm/tiny/Makefile     |   1 +

>>>    drivers/gpu/drm/tiny/simple-dbi.c | 244

>>> ++++++++++++++++++++++++++++++

>>>    3 files changed, 257 insertions(+)

>>>    create mode 100644 drivers/gpu/drm/tiny/simple-dbi.c

>>>

>>> diff --git a/drivers/gpu/drm/tiny/Kconfig

>>> b/drivers/gpu/drm/tiny/Kconfig

>>> index d31be274a2bd..6cfc57b68a46 100644

>>> --- a/drivers/gpu/drm/tiny/Kconfig

>>> +++ b/drivers/gpu/drm/tiny/Kconfig

>>> @@ -144,6 +144,18 @@ config TINYDRM_REPAPER

>>>    

>>>            If M is selected the module will be called repaper.

>>>    

>>> +config TINYDRM_SIMPLE_DBI

>>> +       tristate "DRM support for generic MIPI DBI panels"

>>> +       depends on DRM && SPI

>>> +       select DRM_KMS_HELPER

>>> +       select DRM_KMS_CMA_HELPER

>>> +       select DRM_MIPI_DBI

>>> +       help

>>> +         DRM driver for generic DBI panels that are MIPI DCS

>>> compatible

>>> +         and needs no vendor-specific setup commands.

>>> +

>>> +         If M is selected the module will be called simple-dbi.

>>> +

>>>    config TINYDRM_ST7586

>>>          tristate "DRM support for Sitronix ST7586 display panels"

>>>          depends on DRM && SPI

>>> diff --git a/drivers/gpu/drm/tiny/Makefile

>>> b/drivers/gpu/drm/tiny/Makefile

>>> index e09942895c77..2553de651aa3 100644

>>> --- a/drivers/gpu/drm/tiny/Makefile

>>> +++ b/drivers/gpu/drm/tiny/Makefile

>>> @@ -13,3 +13,4 @@ obj-$(CONFIG_TINYDRM_MI0283QT)                +=

>>> mi0283qt.o

>>>    obj-$(CONFIG_TINYDRM_REPAPER)         += repaper.o

>>>    obj-$(CONFIG_TINYDRM_ST7586)          += st7586.o

>>>    obj-$(CONFIG_TINYDRM_ST7735R)         += st7735r.o

>>> +obj-$(CONFIG_TINYDRM_SIMPLE_DBI)       += simple-dbi.o

>>> diff --git a/drivers/gpu/drm/tiny/simple-dbi.c

>>> b/drivers/gpu/drm/tiny/simple-dbi.c

>>> new file mode 100644

>>> index 000000000000..2b207e43d500

>>> --- /dev/null

>>> +++ b/drivers/gpu/drm/tiny/simple-dbi.c

>>> @@ -0,0 +1,244 @@

>>> +// SPDX-License-Identifier: GPL-2.0+

>>> +/*

>>> + * DRM driver for display panels with configuration preset and

>>> needs only

>>> + * standard MIPI DCS commands to bring up.

>>> + *

>>> + * Copyright (C) 2021 Sipeed

>>> + */

>>> +

>>> +#include <linux/backlight.h>

>>> +#include <linux/delay.h>

>>> +#include <linux/dma-buf.h>

>>> +#include <linux/gpio/consumer.h>

>>> +#include <linux/module.h>

>>> +#include <linux/property.h>

>>> +#include <linux/spi/spi.h>

>>> +#include <video/mipi_display.h>

>>> +

>>> +#include <drm/drm_atomic_helper.h>

>>> +#include <drm/drm_drv.h>

>>> +#include <drm/drm_fb_helper.h>

>>> +#include <drm/drm_gem_atomic_helper.h>

>>> +#include <drm/drm_gem_cma_helper.h>

>>> +#include <drm/drm_managed.h>

>>> +#include <drm/drm_mipi_dbi.h>

>>> +

>>> +#define MIPI_DCS_ADDRESS_MODE_BGR              BIT(3)

>>> +#define MIPI_DCS_ADDRESS_MODE_REVERSE          BIT(5)

>>> +#define MIPI_DCS_ADDRESS_MODE_RTL              BIT(6)

>>> +#define MIPI_DCS_ADDRESS_MODE_BTT              BIT(7)

>>> +

>>> +struct simple_dbi_cfg {

>>> +       const struct drm_display_mode mode;

>>> +       unsigned int left_offset;

>>> +       unsigned int top_offset;

>>> +       bool inverted;

>>> +       bool write_only;

>>> +       bool bgr;

>>> +       bool right_to_left;

>>> +       bool bottom_to_top;

>>> +};

>>> +

>>> +struct simple_dbi_priv {

>>> +       struct mipi_dbi_dev dbidev;     /* Must be first for

>>> .release() */

>>

>> Which release?

> 

> Ah, some copy-n-paste waste.

> 

> Will drop this in v2.

> 

>>

>>> +       const struct simple_dbi_cfg *cfg;

>>> +};

>>> +

>>> +static void simple_dbi_pipe_enable(struct drm_simple_display_pipe

>>> *pipe,

>>> +                               struct drm_crtc_state *crtc_state,

>>> +                               struct drm_plane_state

>>> *plane_state)

>>> +{

>>> +       struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe-

>>>> crtc.dev);

>>> +       struct simple_dbi_priv *priv = container_of(dbidev,

>>> +                                                   struct

>>> simple_dbi_priv,

>>> +                                                   dbidev);

>>> +       struct mipi_dbi *dbi = &dbidev->dbi;

>>> +       int ret, idx;

>>> +       u8 addr_mode = 0x00;

>>> +

>>> +       if (!drm_dev_enter(pipe->crtc.dev, &idx))

>>> +               return;

>>> +

>>> +       DRM_DEBUG_KMS("\n");

>>

>> I'm not a friend of such debugging statements. If you absolutely want

>> to

>> keep it, rather use drm_dbg_kms().

> 

> Should be copy-n-paste waste too.

> 

>>

>>> +

>>> +       ret = mipi_dbi_poweron_reset(dbidev);

>>> +       if (ret)

>>> +               goto out_exit;

>>> +

>>> +       mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);

>>> +       msleep(5);

>>> +

>>> +       /* Currently tinydrm supports 16bit only now */

>>> +       mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT,

>>> +                        MIPI_DCS_PIXEL_FMT_16BIT);

>>> +

>>> +       if (priv->cfg->inverted)

>>> +               mipi_dbi_command(dbi, MIPI_DCS_ENTER_INVERT_MODE);

>>> +       else

>>> +               mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE);

>>> +

>>> +       if (priv->cfg->bgr)

>>> +               addr_mode |= MIPI_DCS_ADDRESS_MODE_BGR;

>>> +

>>> +       if (priv->cfg->right_to_left)

>>> +               addr_mode |= MIPI_DCS_ADDRESS_MODE_RTL;

>>> +

>>> +       if (priv->cfg->bottom_to_top)

>>> +               addr_mode |= MIPI_DCS_ADDRESS_MODE_BTT;

>>> +

>>> +       switch (dbidev->rotation) {

>>> +       default:

>>> +               break;

>>> +       case 90:

>>> +               addr_mode ^= MIPI_DCS_ADDRESS_MODE_REVERSE;

>>> +               addr_mode ^= MIPI_DCS_ADDRESS_MODE_RTL;

>>> +               break;

>>> +       case 180:

>>> +               addr_mode ^= MIPI_DCS_ADDRESS_MODE_RTL;

>>> +               addr_mode ^= MIPI_DCS_ADDRESS_MODE_BTT;

>>> +               break;

>>> +       case 270:

>>> +               addr_mode ^= MIPI_DCS_ADDRESS_MODE_REVERSE;

>>> +               addr_mode ^= MIPI_DCS_ADDRESS_MODE_BTT;

>>> +               break;

>>> +       }

>>> +

>>> +       mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE,

>>> addr_mode);

>>> +

>>> +       mipi_dbi_command(dbi, MIPI_DCS_ENTER_NORMAL_MODE);

>>> +

>>> +       mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);

>>> +

>>> +       mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);

>>> +out_exit:

>>> +       drm_dev_exit(idx);

>>> +}

>>> +

>>> +static const struct drm_simple_display_pipe_funcs

>>> simple_dbi_pipe_funcs = {

>>> +       .enable         = simple_dbi_pipe_enable,

>>> +       .disable        = mipi_dbi_pipe_disable,

>>> +       .update         = mipi_dbi_pipe_update,

>>> +       .prepare_fb     = drm_gem_simple_display_pipe_prepare_fb,

>>> +};

>>> +

>>> +static const struct simple_dbi_cfg zsx154_b1206_cfg = {

>>> +       .mode           = { DRM_SIMPLE_MODE(240, 240, 28, 28) },

>>> +       .inverted       = true,

>>> +       .write_only     = true,

>>> +};

>>> +

>>> +DEFINE_DRM_GEM_CMA_FOPS(simple_dbi_fops);

>>> +

>>> +static const struct drm_driver simple_dbi_driver = {

>>> +       .driver_features        = DRIVER_GEM | DRIVER_MODESET |

>>> DRIVER_ATOMIC,

>>> +       .fops                   = &simple_dbi_fops,

>>> +       DRM_GEM_CMA_DRIVER_OPS_VMAP,

>>> +       .debugfs_init           = mipi_dbi_debugfs_init,

>>> +       .name                   = "simple-dbi",

>>> +       .desc                   = "Generic MIPI-DCS compatible DBI

>>> panel",

>>> +       .date                   = "20210723",

>>> +       .major                  = 1,

>>> +       .minor                  = 0,

>>> +};

>>> +

>>> +static const struct of_device_id simple_dbi_of_match[] = {

>>> +       { .compatible = "zsx,zsx154-b1206", .data =

>>> &zsx154_b1206_cfg },

>>> +       { },

>>> +}

>>> +MODULE_DEVICE_TABLE(of, simple_dbi_of_match);

>>> +

>>> +static int simple_dbi_probe(struct spi_device *spi)

>>> +{

>>> +       struct device *dev = &spi->dev;

>>> +       const struct simple_dbi_cfg *cfg;

>>> +       struct mipi_dbi_dev *dbidev;

>>> +       struct simple_dbi_priv *priv;

>>> +       struct drm_device *drm;

>>> +       struct mipi_dbi *dbi;

>>> +       struct gpio_desc *dc;

>>> +       u32 rotation = 0;

>>> +       int ret;

>>> +

>>> +       cfg = device_get_match_data(&spi->dev);

>>> +       if (!cfg)

>>> +               cfg = (void *)spi_get_device_id(spi)->driver_data;

>>> +

>>> +       priv = devm_drm_dev_alloc(dev, &simple_dbi_driver,

>>> +                                 struct simple_dbi_priv,

>>> dbidev.drm);

>>> +       if (IS_ERR(priv))

>>> +               return PTR_ERR(priv);

>>> +

>>> +       dbidev = &priv->dbidev;

>>> +       priv->cfg = cfg;

>>> +

>>> +       dbi = &dbidev->dbi;

>>> +       drm = &dbidev->drm;

>>> +

>>> +       dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);

>>> +       if (IS_ERR(dbi->reset))

>>> +               return dev_err_probe(dev, PTR_ERR(dbi->reset),

>>> "Failed to get reset GPIO\n");

>>> +

>>> +       dc = devm_gpiod_get_optional(dev, "dc", GPIOD_OUT_LOW);

>>> +       if (IS_ERR(dc))

>>> +               return dev_err_probe(dev, PTR_ERR(dc), "Failed to

>>> get D/C GPIO\n");

>>> +

>>> +       dbidev->backlight = devm_of_find_backlight(dev);

>>> +       if (IS_ERR(dbidev->backlight))

>>> +               return PTR_ERR(dbidev->backlight);

>>> +

>>> +       device_property_read_u32(dev, "rotation", &rotation);

>>> +

>>> +       ret = mipi_dbi_spi_init(spi, dbi, dc);

>>> +       if (ret)

>>> +               return ret;

>>> +

>>> +       if (cfg->write_only)

>>> +               dbi->read_commands = NULL;

>>> +

>>> +       ret = mipi_dbi_dev_init(dbidev, &simple_dbi_pipe_funcs,

>>> &cfg->mode,

>>> +                               rotation);

>>> +       if (ret)

>>> +               return ret;

>>> +

>>> +       drm_mode_config_reset(drm);

>>> +

>>> +       ret = drm_dev_register(drm, 0);

>>> +       if (ret)

>>> +               return ret;

>>> +

>>> +       spi_set_drvdata(spi, drm);

>>

>> AFAIK dev files are being created during drm_dev_register(). It's

>> probably safer to set the drvdata before.

> 

> Okay, thanks.

> 

>>

>>> +

>>> +       drm_fbdev_generic_setup(drm, 0);

>>> +

>>> +       return 0;

>>> +}

>>> +

>>> +static int simple_dbi_remove(struct spi_device *spi)

>>> +{

>>> +       struct drm_device *drm = spi_get_drvdata(spi);

>>> +

>>> +       drm_dev_unplug(drm);

>>> +       drm_atomic_helper_shutdown(drm);

>>> +

>>> +       return 0;

>>> +}

>>> +

>>> +static void simple_dbi_shutdown(struct spi_device *spi)

>>> +{

>>> +       drm_atomic_helper_shutdown(spi_get_drvdata(spi));

>>> +}

>>> +

>>> +static struct spi_driver simple_dbi_spi_driver = {

>>> +       .driver = {

>>> +               .name = "simple-dbi",

>>> +               .of_match_table = simple_dbi_of_match,

>>> +       },

>>> +       .probe = simple_dbi_probe,

>>> +       .remove = simple_dbi_remove,

>>> +       .shutdown = simple_dbi_shutdown,

>>> +};

>>> +module_spi_driver(simple_dbi_spi_driver);

>>> +

>>> +MODULE_DESCRIPTION("Simple DBI panel DRM driver");

>>> +MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");

>>> +MODULE_LICENSE("GPL");

>>>

>>

>> Trailing blank line. (?)

> 

> Ah I do not know what happened, I just `git format-patch` and then `git

> send-email`.

> 

> At least I have no trailing blank line in the file inside patch :-)


No problem. Could have been my email client.

After you cleaned up the patch as you outlined above, you can add

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>


to the patch. I don't have much insight into the MIPI code. Maybe ask 
for someone else's review as well.

Best regards
Thomas

> 

>>

>> Best regards

>> Thomas

>>

> 

> 


-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer
Rob Herring (Arm) Aug. 6, 2021, 9:46 p.m. UTC | #2 
On Mon, Aug 02, 2021 at 02:35:36PM +0800, Icenowy Zheng wrote:
> As we're going to introduce a driver for MIPI DBI panels that need only

> standard MIPI-DCS commands to initialize (usually because the controller

> has some configuration pre-programmed), add a DT binding file for it,

> which now includes only one DBI Type C Option 3 panel, ZSX154-B1206.

> 

> Signed-off-by: Icenowy Zheng <icenowy@sipeed.com>

> ---

>  .../bindings/display/simple-dbi.yaml          | 72 +++++++++++++++++++

>  1 file changed, 72 insertions(+)

>  create mode 100644 Documentation/devicetree/bindings/display/simple-dbi.yaml

> 

> diff --git a/Documentation/devicetree/bindings/display/simple-dbi.yaml b/Documentation/devicetree/bindings/display/simple-dbi.yaml

> new file mode 100644

> index 000000000000..f49b0fda0935

> --- /dev/null

> +++ b/Documentation/devicetree/bindings/display/simple-dbi.yaml

> @@ -0,0 +1,72 @@

> +# SPDX-License-Identifier: GPL-2.0-only


checkpatch.pl will tell you this should be dual licensed.