[PATCH v4 3/5] drm/tinydrm: add support for LEGO MINDSTORMS EV3 LCD
Noralf Trønnes
noralf at tronnes.org
Fri Aug 11 09:40:41 PDT 2017
Den 09.08.2017 19.59, skrev Noralf Trønnes:
>
> Den 07.08.2017 19.39, skrev David Lechner:
>> LEGO MINDSTORMS EV3 has an LCD with a ST7586 controller. This adds a new
>> module for the ST7586 controller with parameters for the LEGO MINDSTORMS
>> EV3 LCD display.
>>
>> Signed-off-by: David Lechner <david at lechnology.com>
>> ---
>
> This looks good, even I understand the pixel packing now :-)
> Now we wait for the DT maintainers to have their say.
>
> Reviewed-by: Noralf Trønnes <noralf at tronnes.org>
>
Thanks, applied to drm-misc together with dt binding.
Noralf.
>> v4 changes:
>> * correct order for MAINTAINERS entry
>> * Drop code not used by LEGO EV3 (regulator, backlight, suspend/resume)
>> * Make gpios required
>> * Use lookup table for pixel packing algorithm
>> * Don't modify clip when used as function parameter
>> * Use roundup/rounddown macros
>>
>>
>> MAINTAINERS | 6 +
>> drivers/gpu/drm/tinydrm/Kconfig | 10 +
>> drivers/gpu/drm/tinydrm/Makefile | 1 +
>> drivers/gpu/drm/tinydrm/st7586.c | 428
>> +++++++++++++++++++++++++++++++++++++++
>> 4 files changed, 445 insertions(+)
>> create mode 100644 drivers/gpu/drm/tinydrm/st7586.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index a1e772e..19ca3e6 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -4380,6 +4380,12 @@ S: Orphan / Obsolete
>> F: drivers/gpu/drm/sis/
>> F: include/uapi/drm/sis_drm.h
>> +DRM DRIVER FOR SITRONIX ST7586 PANELS
>> +M: David Lechner <david at lechnology.com>
>> +S: Maintained
>> +F: drivers/gpu/drm/tinydrm/st7586.c
>> +F: Documentation/devicetree/bindings/display/st7586.txt
>> +
>> DRM DRIVER FOR TDFX VIDEO CARDS
>> S: Orphan / Obsolete
>> F: drivers/gpu/drm/tdfx/
>> diff --git a/drivers/gpu/drm/tinydrm/Kconfig
>> b/drivers/gpu/drm/tinydrm/Kconfig
>> index f17c3ca..2e790e7 100644
>> --- a/drivers/gpu/drm/tinydrm/Kconfig
>> +++ b/drivers/gpu/drm/tinydrm/Kconfig
>> @@ -32,3 +32,13 @@ config TINYDRM_REPAPER
>> 2.71" TFT EPD Panel (E2271CS021)
>> If M is selected the module will be called repaper.
>> +
>> +config TINYDRM_ST7586
>> + tristate "DRM support for Sitronix ST7586 display panels"
>> + depends on DRM_TINYDRM && SPI
>> + select TINYDRM_MIPI_DBI
>> + help
>> + DRM driver for the following Sitronix ST7586 panels:
>> + * LEGO MINDSTORMS EV3
>> +
>> + If M is selected the module will be called st7586.
>> diff --git a/drivers/gpu/drm/tinydrm/Makefile
>> b/drivers/gpu/drm/tinydrm/Makefile
>> index 95bb4d4..0c184bd 100644
>> --- a/drivers/gpu/drm/tinydrm/Makefile
>> +++ b/drivers/gpu/drm/tinydrm/Makefile
>> @@ -6,3 +6,4 @@ obj-$(CONFIG_TINYDRM_MIPI_DBI) += mipi-dbi.o
>> # Displays
>> obj-$(CONFIG_TINYDRM_MI0283QT) += mi0283qt.o
>> obj-$(CONFIG_TINYDRM_REPAPER) += repaper.o
>> +obj-$(CONFIG_TINYDRM_ST7586) += st7586.o
>> diff --git a/drivers/gpu/drm/tinydrm/st7586.c
>> b/drivers/gpu/drm/tinydrm/st7586.c
>> new file mode 100644
>> index 0000000..1b39d3f
>> --- /dev/null
>> +++ b/drivers/gpu/drm/tinydrm/st7586.c
>> @@ -0,0 +1,428 @@
>> +/*
>> + * DRM driver for Sitronix ST7586 panels
>> + *
>> + * Copyright 2017 David Lechner <david at lechnology.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + */
>> +
>> +#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/tinydrm/mipi-dbi.h>
>> +#include <drm/tinydrm/tinydrm-helpers.h>
>> +
>> +/* controller-specific commands */
>> +#define ST7586_DISP_MODE_GRAY 0x38
>> +#define ST7586_DISP_MODE_MONO 0x39
>> +#define ST7586_ENABLE_DDRAM 0x3a
>> +#define ST7586_SET_DISP_DUTY 0xb0
>> +#define ST7586_SET_PART_DISP 0xb4
>> +#define ST7586_SET_NLINE_INV 0xb5
>> +#define ST7586_SET_VOP 0xc0
>> +#define ST7586_SET_BIAS_SYSTEM 0xc3
>> +#define ST7586_SET_BOOST_LEVEL 0xc4
>> +#define ST7586_SET_VOP_OFFSET 0xc7
>> +#define ST7586_ENABLE_ANALOG 0xd0
>> +#define ST7586_AUTO_READ_CTRL 0xd7
>> +#define ST7586_OTP_RW_CTRL 0xe0
>> +#define ST7586_OTP_CTRL_OUT 0xe1
>> +#define ST7586_OTP_READ 0xe3
>> +
>> +#define ST7586_DISP_CTRL_MX BIT(6)
>> +#define ST7586_DISP_CTRL_MY BIT(7)
>> +
>> +/*
>> + * The ST7586 controller has an unusual pixel format where 2bpp
>> grayscale is
>> + * packed 3 pixels per byte with the first two pixels using 3 bits
>> and the 3rd
>> + * pixel using only 2 bits.
>> + *
>> + * | D7 | D6 | D5 || | || 2bpp |
>> + * | (D4) | (D3) | (D2) || D1 | D0 || GRAY |
>> + * +------+------+------++------+------++------+
>> + * | 1 | 1 | 1 || 1 | 1 || 0 0 | black
>> + * | 1 | 0 | 0 || 1 | 0 || 0 1 | dark gray
>> + * | 0 | 1 | 0 || 0 | 1 || 1 0 | light gray
>> + * | 0 | 0 | 0 || 0 | 0 || 1 1 | white
>> + */
>> +
>> +static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };
>> +
>> +static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
>> + struct drm_framebuffer *fb,
>> + struct drm_clip_rect *clip)
>> +{
>> + size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
>> + unsigned int x, y;
>> + u8 *src, *buf, val;
>> +
>> + buf = kmalloc(len, GFP_KERNEL);
>> + if (!buf)
>> + return;
>> +
>> + tinydrm_xrgb8888_to_gray8(buf, vaddr, fb, clip);
>> + src = buf;
>> +
>> + for (y = clip->y1; y < clip->y2; y++) {
>> + for (x = clip->x1; x < clip->x2; x += 3) {
>> + val = st7586_lookup[*src++ >> 6] << 5;
>> + val |= st7586_lookup[*src++ >> 6] << 2;
>> + val |= st7586_lookup[*src++ >> 6] >> 1;
>> + *dst++ = val;
>> + }
>> + }
>> +
>> + kfree(buf);
>> +}
>> +
>> +static int st7586_buf_copy(void *dst, struct drm_framebuffer *fb,
>> + struct drm_clip_rect *clip)
>> +{
>> + struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
>> + struct dma_buf_attachment *import_attach =
>> cma_obj->base.import_attach;
>> + void *src = cma_obj->vaddr;
>> + int ret = 0;
>> +
>> + if (import_attach) {
>> + ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
>> + DMA_FROM_DEVICE);
>> + if (ret)
>> + return ret;
>> + }
>> +
>> + st7586_xrgb8888_to_gray332(dst, src, fb, clip);
>> +
>> + if (import_attach)
>> + ret = dma_buf_end_cpu_access(import_attach->dmabuf,
>> + DMA_FROM_DEVICE);
>> +
>> + return ret;
>> +}
>> +
>> +static int st7586_fb_dirty(struct drm_framebuffer *fb,
>> + struct drm_file *file_priv, unsigned int flags,
>> + unsigned int color, struct drm_clip_rect *clips,
>> + unsigned int num_clips)
>> +{
>> + struct tinydrm_device *tdev = fb->dev->dev_private;
>> + struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
>> + struct drm_clip_rect clip;
>> + int start, end;
>> + int ret = 0;
>> +
>> + mutex_lock(&tdev->dirty_lock);
>> +
>> + if (!mipi->enabled)
>> + goto out_unlock;
>> +
>> + /* fbdev can flush even when we're not interested */
>> + if (tdev->pipe.plane.fb != fb)
>> + goto out_unlock;
>> +
>> + tinydrm_merge_clips(&clip, clips, num_clips, flags, fb->width,
>> + fb->height);
>> +
>> + /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
>> + clip.x1 = rounddown(clip.x1, 3);
>> + clip.x2 = roundup(clip.x2, 3);
>> +
>> + DRM_DEBUG("Flushing [FB:%d] x1=%u, x2=%u, y1=%u, y2=%u\n",
>> fb->base.id,
>> + clip.x1, clip.x2, clip.y1, clip.y2);
>> +
>> + ret = st7586_buf_copy(mipi->tx_buf, fb, &clip);
>> + if (ret)
>> + goto out_unlock;
>> +
>> + /* Pixels are packed 3 per byte */
>> + start = clip.x1 / 3;
>> + end = clip.x2 / 3;
>> +
>> + mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS,
>> + (start >> 8) & 0xFF, start & 0xFF,
>> + (end >> 8) & 0xFF, (end - 1) & 0xFF);
>> + mipi_dbi_command(mipi, MIPI_DCS_SET_PAGE_ADDRESS,
>> + (clip.y1 >> 8) & 0xFF, clip.y1 & 0xFF,
>> + (clip.y2 >> 8) & 0xFF, (clip.y2 - 1) & 0xFF);
>> +
>> + ret = mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START,
>> + (u8 *)mipi->tx_buf,
>> + (end - start) * (clip.y2 - clip.y1));
>> +
>> +out_unlock:
>> + mutex_unlock(&tdev->dirty_lock);
>> +
>> + if (ret)
>> + dev_err_once(fb->dev->dev, "Failed to update display %d\n",
>> + ret);
>> +
>> + return ret;
>> +}
>> +
>> +static const struct drm_framebuffer_funcs st7586_fb_funcs = {
>> + .destroy = drm_fb_cma_destroy,
>> + .create_handle = drm_fb_cma_create_handle,
>> + .dirty = st7586_fb_dirty,
>> +};
>> +
>> +void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
>> + struct drm_crtc_state *crtc_state)
>> +{
>> + struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
>> + struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
>> + struct drm_framebuffer *fb = pipe->plane.fb;
>> + struct device *dev = tdev->drm->dev;
>> + int ret;
>> + u8 addr_mode;
>> +
>> + DRM_DEBUG_KMS("\n");
>> +
>> + mipi_dbi_hw_reset(mipi);
>> + ret = mipi_dbi_command(mipi, ST7586_AUTO_READ_CTRL, 0x9f);
>> + if (ret) {
>> + dev_err(dev, "Error sending command %d\n", ret);
>> + return;
>> + }
>> +
>> + mipi_dbi_command(mipi, ST7586_OTP_RW_CTRL, 0x00);
>> +
>> + msleep(10);
>> +
>> + mipi_dbi_command(mipi, ST7586_OTP_READ);
>> +
>> + msleep(20);
>> +
>> + mipi_dbi_command(mipi, ST7586_OTP_CTRL_OUT);
>> + mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
>> + mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
>> +
>> + msleep(50);
>> +
>> + mipi_dbi_command(mipi, ST7586_SET_VOP_OFFSET, 0x00);
>> + mipi_dbi_command(mipi, ST7586_SET_VOP, 0xe3, 0x00);
>> + mipi_dbi_command(mipi, ST7586_SET_BIAS_SYSTEM, 0x02);
>> + mipi_dbi_command(mipi, ST7586_SET_BOOST_LEVEL, 0x04);
>> + mipi_dbi_command(mipi, ST7586_ENABLE_ANALOG, 0x1d);
>> + mipi_dbi_command(mipi, ST7586_SET_NLINE_INV, 0x00);
>> + mipi_dbi_command(mipi, ST7586_DISP_MODE_GRAY);
>> + mipi_dbi_command(mipi, ST7586_ENABLE_DDRAM, 0x02);
>> +
>> + switch (mipi->rotation) {
>> + default:
>> + addr_mode = 0x00;
>> + break;
>> + case 90:
>> + addr_mode = ST7586_DISP_CTRL_MY;
>> + break;
>> + case 180:
>> + addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
>> + break;
>> + case 270:
>> + addr_mode = ST7586_DISP_CTRL_MX;
>> + break;
>> + }
>> + mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
>> +
>> + mipi_dbi_command(mipi, ST7586_SET_DISP_DUTY, 0x7f);
>> + mipi_dbi_command(mipi, ST7586_SET_PART_DISP, 0xa0);
>> + mipi_dbi_command(mipi, MIPI_DCS_SET_PARTIAL_AREA, 0x00, 0x00,
>> 0x00, 0x77);
>> + mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);
>> +
>> + msleep(100);
>> +
>> + mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
>> +
>> + mipi->enabled = true;
>> +
>> + if (fb)
>> + fb->funcs->dirty(fb, NULL, 0, 0, NULL, 0);
>> +}
>> +
>> +static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
>> +{
>> + struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
>> + struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
>> +
>> + DRM_DEBUG_KMS("\n");
>> +
>> + if (!mipi->enabled)
>> + return;
>> +
>> + mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
>> + mipi->enabled = false;
>> +}
>> +
>> +static const u32 st7586_formats[] = {
>> + DRM_FORMAT_XRGB8888,
>> +};
>> +
>> +static int st7586_init(struct device *dev, struct mipi_dbi *mipi,
>> + const struct drm_simple_display_pipe_funcs *pipe_funcs,
>> + struct drm_driver *driver, const struct drm_display_mode *mode,
>> + unsigned int rotation)
>> +{
>> + size_t bufsize = (mode->vdisplay + 2) / 3 * mode->hdisplay;
>> + struct tinydrm_device *tdev = &mipi->tinydrm;
>> + int ret;
>> +
>> + mutex_init(&mipi->cmdlock);
>> +
>> + mipi->tx_buf = devm_kmalloc(dev, bufsize, GFP_KERNEL);
>> + if (!mipi->tx_buf)
>> + return -ENOMEM;
>> +
>> + ret = devm_tinydrm_init(dev, tdev, &st7586_fb_funcs, driver);
>> + if (ret)
>> + return ret;
>> +
>> + ret = tinydrm_display_pipe_init(tdev, pipe_funcs,
>> + DRM_MODE_CONNECTOR_VIRTUAL,
>> + st7586_formats,
>> + ARRAY_SIZE(st7586_formats),
>> + mode, rotation);
>> + if (ret)
>> + return ret;
>> +
>> + tdev->drm->mode_config.preferred_depth = 32;
>> + mipi->rotation = rotation;
>> +
>> + drm_mode_config_reset(tdev->drm);
>> +
>> + DRM_DEBUG_KMS("preferred_depth=%u, rotation = %u\n",
>> + tdev->drm->mode_config.preferred_depth, rotation);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
>> + .enable = st7586_pipe_enable,
>> + .disable = st7586_pipe_disable,
>> + .update = tinydrm_display_pipe_update,
>> + .prepare_fb = tinydrm_display_pipe_prepare_fb,
>> +};
>> +
>> +static const struct drm_display_mode st7586_mode = {
>> + TINYDRM_MODE(178, 128, 37, 27),
>> +};
>> +
>> +DEFINE_DRM_GEM_CMA_FOPS(st7586_fops);
>> +
>> +static struct drm_driver st7586_driver = {
>> + .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
>> + DRIVER_ATOMIC,
>> + .fops = &st7586_fops,
>> + TINYDRM_GEM_DRIVER_OPS,
>> + .lastclose = tinydrm_lastclose,
>> + .debugfs_init = mipi_dbi_debugfs_init,
>> + .name = "st7586",
>> + .desc = "Sitronix ST7586",
>> + .date = "20170801",
>> + .major = 1,
>> + .minor = 0,
>> +};
>> +
>> +static const struct of_device_id st7586_of_match[] = {
>> + { .compatible = "lego,ev3-lcd" },
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(of, st7586_of_match);
>> +
>> +static const struct spi_device_id st7586_id[] = {
>> + { "ev3-lcd", 0 },
>> + { },
>> +};
>> +MODULE_DEVICE_TABLE(spi, st7586_id);
>> +
>> +static int st7586_probe(struct spi_device *spi)
>> +{
>> + struct device *dev = &spi->dev;
>> + struct tinydrm_device *tdev;
>> + struct mipi_dbi *mipi;
>> + struct gpio_desc *a0;
>> + u32 rotation = 0;
>> + int ret;
>> +
>> + mipi = devm_kzalloc(dev, sizeof(*mipi), GFP_KERNEL);
>> + if (!mipi)
>> + return -ENOMEM;
>> +
>> + mipi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
>> + if (IS_ERR(mipi->reset)) {
>> + dev_err(dev, "Failed to get gpio 'reset'\n");
>> + return PTR_ERR(mipi->reset);
>> + }
>> +
>> + a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
>> + if (IS_ERR(a0)) {
>> + dev_err(dev, "Failed to get gpio 'a0'\n");
>> + return PTR_ERR(a0);
>> + }
>> +
>> + device_property_read_u32(dev, "rotation", &rotation);
>> +
>> + ret = mipi_dbi_spi_init(spi, mipi, a0);
>> + if (ret)
>> + return ret;
>> +
>> + /* Cannot read from this controller via SPI */
>> + mipi->read_commands = NULL;
>> +
>> + /*
>> + * we are using 8-bit data, so we are not actually swapping
>> anything,
>> + * but setting mipi->swap_bytes makes mipi_dbi_typec3_command()
>> do the
>> + * right thing and not use 16-bit transfers (which results in
>> swapped
>> + * bytes on little-endian systems and causes out of order data
>> to be
>> + * sent to the display).
>> + */
>> + mipi->swap_bytes = true;
>> +
>> + ret = st7586_init(&spi->dev, mipi, &st7586_pipe_funcs,
>> &st7586_driver,
>> + &st7586_mode, rotation);
>> + if (ret)
>> + return ret;
>> +
>> + tdev = &mipi->tinydrm;
>> +
>> + ret = devm_tinydrm_register(tdev);
>> + if (ret)
>> + return ret;
>> +
>> + spi_set_drvdata(spi, mipi);
>> +
>> + DRM_DEBUG_DRIVER("Initialized %s:%s @%uMHz on minor %d\n",
>> + tdev->drm->driver->name, dev_name(dev),
>> + spi->max_speed_hz / 1000000,
>> + tdev->drm->primary->index);
>> +
>> + return 0;
>> +}
>> +
>> +static void st7586_shutdown(struct spi_device *spi)
>> +{
>> + struct mipi_dbi *mipi = spi_get_drvdata(spi);
>> +
>> + tinydrm_shutdown(&mipi->tinydrm);
>> +}
>> +
>> +static struct spi_driver st7586_spi_driver = {
>> + .driver = {
>> + .name = "st7586",
>> + .owner = THIS_MODULE,
>> + .of_match_table = st7586_of_match,
>> + },
>> + .id_table = st7586_id,
>> + .probe = st7586_probe,
>> + .shutdown = st7586_shutdown,
>> +};
>> +module_spi_driver(st7586_spi_driver);
>> +
>> +MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
>> +MODULE_AUTHOR("David Lechner <david at lechnology.com>");
>> +MODULE_LICENSE("GPL");
>
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