Commit eac99d4a authored by David Lechner's avatar David Lechner Committed by Noralf Trønnes

drm/tinydrm: add support for LEGO MINDSTORMS EV3 LCD

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: default avatarDavid Lechner <david@lechnology.com>
Reviewed-by: default avatarNoralf Trønnes <noralf@tronnes.org>
Signed-off-by: default avatarNoralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1502127581-10517-4-git-send-email-david@lechnology.com
parent aee02b0f
......@@ -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@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/
......
......@@ -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.
......@@ -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
/*
* 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/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@lechnology.com>");
MODULE_LICENSE("GPL");
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