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    Subject[PATCH v3 4/6] drm/tinydrm: add support for LEGO MINDSTORMS EV3 LCD
    Date
    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@lechnology.com>
    ---
    MAINTAINERS | 6 +
    drivers/gpu/drm/tinydrm/Kconfig | 10 +
    drivers/gpu/drm/tinydrm/Makefile | 1 +
    drivers/gpu/drm/tinydrm/st7586.c | 466 +++++++++++++++++++++++++++++++++++++++
    4 files changed, 483 insertions(+)
    create mode 100644 drivers/gpu/drm/tinydrm/st7586.c

    diff --git a/MAINTAINERS b/MAINTAINERS
    index a1e772e..9643f95 100644
    --- a/MAINTAINERS
    +++ b/MAINTAINERS
    @@ -4365,6 +4365,12 @@ S: Maintained
    F: drivers/gpu/drm/tinydrm/repaper.c
    F: Documentation/devicetree/bindings/display/repaper.txt

    +DRM DRIVER FOR SITRONIX ST7586 PANELS
    +M: David Lechner <david@lechnology.com>
    +S: Maintained
    +F: drivers/gpu/drm/tinydrm/st7586.c
    +F: Documentation/devicetree/bindings/display/st7586.txt
    +
    DRM DRIVER FOR RAGE 128 VIDEO CARDS
    S: Orphan / Obsolete
    F: drivers/gpu/drm/r128/
    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..11e226d
    --- /dev/null
    +++ b/drivers/gpu/drm/tinydrm/st7586.c
    @@ -0,0 +1,466 @@
    +/*
    + * DRM driver for Sitronix ST7586 panels
    + *
    + * Copyright 2017 David Lechner <david@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/regulator/consumer.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)
    +
    +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;
    +
    + /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
    + clip->x1 = clip->x1 / 3 * 3;
    + clip->x2 = (clip->x2 + 2) / 3 * 3;
    +
    + 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 = *src++ & 0xc0;
    + if (val & 0xc0)
    + val |= 0x20;
    + val |= (*src++ & 0xc0) >> 3;
    + if (val & 0x18)
    + val |= 0x04;
    + val |= *src++ >> 6;
    + *dst++ = ~val;
    + }
    + }
    +
    + /* now adjust the clip so it applies to dst */
    + clip->x1 /= 3;
    + clip->x2 /= 3;
    +
    + 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;
    + struct drm_format_name_buf format_name;
    + 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;
    + }
    +
    + switch (fb->format->format) {
    + case DRM_FORMAT_XRGB8888:
    + st7586_xrgb8888_to_gray332(dst, src, fb, clip);
    + break;
    + default:
    + dev_err_once(fb->dev->dev, "Format is not supported: %s\n",
    + drm_get_format_name(fb->format->format,
    + &format_name));
    + ret = -EINVAL;
    + break;
    + }
    +
    + if (import_attach)
    + 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 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);
    +
    + 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;
    +
    + /* NB: st7586_buf_copy() modifies clip */
    +
    + mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS,
    + (clip.x1 >> 8) & 0xFF, clip.x1 & 0xFF,
    + (clip.x2 >> 8) & 0xFF, (clip.x2 - 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,
    + (clip.x2 - clip.x1) * (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");
    +
    + ret = regulator_enable(mipi->regulator);
    + if (ret) {
    + dev_err(dev, "Failed to enable regulator %d\n", ret);
    + return;
    + }
    +
    + 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);
    + regulator_disable(mipi->regulator);
    + 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);
    +
    + tinydrm_enable_backlight(mipi->backlight);
    +}
    +
    +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->enabled = false;
    + tinydrm_disable_backlight(mipi->backlight);
    + mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
    + regulator_disable(mipi->regulator);
    +}
    +
    +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 *dc;
    + u32 rotation = 0;
    + int ret;
    +
    + mipi = devm_kzalloc(dev, sizeof(*mipi), GFP_KERNEL);
    + if (!mipi)
    + return -ENOMEM;
    +
    + mipi->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
    + if (IS_ERR(mipi->reset)) {
    + dev_err(dev, "Failed to get gpio 'reset'\n");
    + return PTR_ERR(mipi->reset);
    + }
    +
    + dc = devm_gpiod_get_optional(dev, "dc", GPIOD_OUT_LOW);
    + if (IS_ERR(dc)) {
    + dev_err(dev, "Failed to get gpio 'dc'\n");
    + return PTR_ERR(dc);
    + }
    +
    + mipi->regulator = devm_regulator_get(dev, "power");
    + if (IS_ERR(mipi->regulator))
    + return PTR_ERR(mipi->regulator);
    +
    + mipi->backlight = tinydrm_of_find_backlight(dev);
    + if (IS_ERR(mipi->backlight))
    + return PTR_ERR(mipi->backlight);
    +
    + device_property_read_u32(dev, "rotation", &rotation);
    +
    + ret = mipi_dbi_spi_init(spi, mipi, dc);
    + 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 int __maybe_unused st7586_pm_suspend(struct device *dev)
    +{
    + struct mipi_dbi *mipi = dev_get_drvdata(dev);
    +
    + return tinydrm_suspend(&mipi->tinydrm);
    +}
    +
    +static int __maybe_unused st7586_pm_resume(struct device *dev)
    +{
    + struct mipi_dbi *mipi = dev_get_drvdata(dev);
    +
    + return tinydrm_resume(&mipi->tinydrm);
    +}
    +
    +static const struct dev_pm_ops st7586_pm_ops = {
    + SET_SYSTEM_SLEEP_PM_OPS(st7586_pm_suspend, st7586_pm_resume)
    +};
    +
    +static struct spi_driver st7586_spi_driver = {
    + .driver = {
    + .name = "st7586",
    + .owner = THIS_MODULE,
    + .of_match_table = st7586_of_match,
    + .pm = &st7586_pm_ops,
    + },
    + .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@lechnology.com>");
    +MODULE_LICENSE("GPL");
    --
    2.7.4
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      Last update: 2017-08-04 00:35    [W:4.001 / U:0.044 seconds]
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