// SPDX-License-Identifier: GPL-2.0-or-later
/*
* DRM driver for Sitronix ST7586 panels
*
* Copyright 2017 David Lechner <[email protected]>
*/
#include <linux/delay.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_damage_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_fb_dma_helper.h>
#include <drm/drm_fbdev_dma.h>
#include <drm/drm_format_helper.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_managed.h>
#include <drm/drm_mipi_dbi.h>
#include <drm/drm_rect.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_rect *clip,
struct drm_format_conv_state *fmtcnv_state)
{
size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
unsigned int x, y;
u8 *src, *buf, val;
struct iosys_map dst_map, vmap;
buf = kmalloc(len, GFP_KERNEL);
if (!buf)
return;
iosys_map_set_vaddr(&dst_map, buf);
iosys_map_set_vaddr(&vmap, vaddr);
drm_fb_xrgb8888_to_gray8(&dst_map, NULL, &vmap, fb, clip, fmtcnv_state);
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 iosys_map *src, struct drm_framebuffer *fb,
struct drm_rect *clip, struct drm_format_conv_state *fmtcnv_state)
{
int ret;
ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
if (ret)
return ret;
st7586_xrgb8888_to_gray332(dst, src->vaddr, fb, clip, fmtcnv_state);
drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
return 0;
}
static void st7586_fb_dirty(struct iosys_map *src, struct drm_framebuffer *fb,
struct drm_rect *rect, struct drm_format_conv_state *fmtcnv_state)
{
struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);
struct mipi_dbi *dbi = &dbidev->dbi;
int start, end, ret = 0;
/* 3 pixels per byte, so grow clip to nearest multiple of 3 */
rect->x1 = rounddown(rect->x1, 3);
rect->x2 = roundup(rect->x2, 3);
DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
ret = st7586_buf_copy(dbidev->tx_buf, src, fb, rect, fmtcnv_state);
if (ret)
goto err_msg;
/* Pixels are packed 3 per byte */
start = rect->x1 / 3;
end = rect->x2 / 3;
mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS,
(start >> 8) & 0xFF, start & 0xFF,
(end >> 8) & 0xFF, (end - 1) & 0xFF);
mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS,
(rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF,
(rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF);
ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START,
(u8 *)dbidev->tx_buf,
(end - start) * (rect->y2 - rect->y1));
err_msg:
if (ret)
dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
}
static void st7586_pipe_update(struct drm_simple_display_pipe *pipe,
struct drm_plane_state *old_state)
{
struct drm_plane_state *state = pipe->plane.state;
struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);
struct drm_framebuffer *fb = state->fb;
struct drm_rect rect;
int idx;
if (!pipe->crtc.state->active)
return;
if (!drm_dev_enter(fb->dev, &idx))
return;
if (drm_atomic_helper_damage_merged(old_state, state, &rect))
st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect,
&shadow_plane_state->fmtcnv_state);
drm_dev_exit(idx);
}
static void st7586_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 drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
struct drm_framebuffer *fb = plane_state->fb;
struct mipi_dbi *dbi = &dbidev->dbi;
struct drm_rect rect = {
.x1 = 0,
.x2 = fb->width,
.y1 = 0,
.y2 = fb->height,
};
int idx, ret;
u8 addr_mode;
if (!drm_dev_enter(pipe->crtc.dev, &idx))
return;
DRM_DEBUG_KMS("\n");
ret = mipi_dbi_poweron_reset(dbidev);
if (ret)
goto out_exit;
mipi_dbi_command(dbi, ST7586_AUTO_READ_CTRL, 0x9f);
mipi_dbi_command(dbi, ST7586_OTP_RW_CTRL, 0x00);
msleep(10);
mipi_dbi_command(dbi, ST7586_OTP_READ);
msleep(20);
mipi_dbi_command(dbi, ST7586_OTP_CTRL_OUT);
mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
msleep(50);
mipi_dbi_command(dbi, ST7586_SET_VOP_OFFSET, 0x00);
mipi_dbi_command(dbi, ST7586_SET_VOP, 0xe3, 0x00);
mipi_dbi_command(dbi, ST7586_SET_BIAS_SYSTEM, 0x02);
mipi_dbi_command(dbi, ST7586_SET_BOOST_LEVEL, 0x04);
mipi_dbi_command(dbi, ST7586_ENABLE_ANALOG, 0x1d);
mipi_dbi_command(dbi, ST7586_SET_NLINE_INV, 0x00);
mipi_dbi_command(dbi, ST7586_DISP_MODE_GRAY);
mipi_dbi_command(dbi, ST7586_ENABLE_DDRAM, 0x02);
switch (dbidev->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(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
mipi_dbi_command(dbi, ST7586_SET_DISP_DUTY, 0x7f);
mipi_dbi_command(dbi, ST7586_SET_PART_DISP, 0xa0);
mipi_dbi_command(dbi, MIPI_DCS_SET_PARTIAL_ROWS, 0x00, 0x00, 0x00, 0x77);
mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE);
msleep(100);
st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect,
&shadow_plane_state->fmtcnv_state);
mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
out_exit:
drm_dev_exit(idx);
}
static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
{
struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
/*
* This callback is not protected by drm_dev_enter/exit since we want to
* turn off the display on regular driver unload. It's highly unlikely
* that the underlying SPI controller is gone should this be called after
* unplug.
*/
DRM_DEBUG_KMS("\n");
mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF);
}
static const u32 st7586_formats[] = {
DRM_FORMAT_XRGB8888,
};
static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
.mode_valid = mipi_dbi_pipe_mode_valid,
.enable = st7586_pipe_enable,
.disable = st7586_pipe_disable,
.update = st7586_pipe_update,
.begin_fb_access = mipi_dbi_pipe_begin_fb_access,
.end_fb_access = mipi_dbi_pipe_end_fb_access,
.reset_plane = mipi_dbi_pipe_reset_plane,
.duplicate_plane_state = mipi_dbi_pipe_duplicate_plane_state,
.destroy_plane_state = mipi_dbi_pipe_destroy_plane_state,
};
static const struct drm_display_mode st7586_mode = {
DRM_SIMPLE_MODE(178, 128, 37, 27),
};
DEFINE_DRM_GEM_DMA_FOPS(st7586_fops);
static const struct drm_driver st7586_driver = {
.driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
.fops = &st7586_fops,
DRM_GEM_DMA_DRIVER_OPS_VMAP,
.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 mipi_dbi_dev *dbidev;
struct drm_device *drm;
struct mipi_dbi *dbi;
struct gpio_desc *a0;
u32 rotation = 0;
size_t bufsize;
int ret;
dbidev = devm_drm_dev_alloc(dev, &st7586_driver,
struct mipi_dbi_dev, drm);
if (IS_ERR(dbidev))
return PTR_ERR(dbidev);
dbi = &dbidev->dbi;
drm = &dbidev->drm;
bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay;
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 GPIO 'reset'\n");
a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
if (IS_ERR(a0))
return dev_err_probe(dev, PTR_ERR(a0), "Failed to get GPIO 'a0'\n");
device_property_read_u32(dev, "rotation", &rotation);
ret = mipi_dbi_spi_init(spi, dbi, a0);
if (ret)
return ret;
/* Cannot read from this controller via SPI */
dbi->read_commands = NULL;
ret = mipi_dbi_dev_init_with_formats(dbidev, &st7586_pipe_funcs,
st7586_formats, ARRAY_SIZE(st7586_formats),
&st7586_mode, rotation, bufsize);
if (ret)
return ret;
/*
* 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).
*/
dbi->swap_bytes = true;
drm_mode_config_reset(drm);
ret = drm_dev_register(drm, 0);
if (ret)
return ret;
spi_set_drvdata(spi, drm);
drm_fbdev_dma_setup(drm, 0);
return 0;
}
static void st7586_remove(struct spi_device *spi)
{
struct drm_device *drm = spi_get_drvdata(spi);
drm_dev_unplug(drm);
drm_atomic_helper_shutdown(drm);
}
static void st7586_shutdown(struct spi_device *spi)
{
drm_atomic_helper_shutdown(spi_get_drvdata(spi));
}
static struct spi_driver st7586_spi_driver = {
.driver = {
.name = "st7586",
.of_match_table = st7586_of_match,
},
.id_table = st7586_id,
.probe = st7586_probe,
.remove = st7586_remove,
.shutdown = st7586_shutdown,
};
module_spi_driver(st7586_spi_driver);
MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
MODULE_AUTHOR("David Lechner <[email protected]>");
MODULE_LICENSE("GPL");
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