diff options
Diffstat (limited to 'drivers/gpu/drm/tiny/st7586.c')
| -rw-r--r-- | drivers/gpu/drm/tiny/st7586.c | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/drivers/gpu/drm/tiny/st7586.c b/drivers/gpu/drm/tiny/st7586.c new file mode 100644 index 000000000000..3cc21a1b30c8 --- /dev/null +++ b/drivers/gpu/drm/tiny/st7586.c @@ -0,0 +1,424 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * DRM driver for Sitronix ST7586 panels + * + * Copyright 2017 David Lechner <david@lechnology.com> + */ + +#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_damage_helper.h> +#include <drm/drm_drv.h> +#include <drm/drm_fb_cma_helper.h> +#include <drm/drm_fb_helper.h> +#include <drm/drm_format_helper.h> +#include <drm/drm_gem_cma_helper.h> +#include <drm/drm_gem_framebuffer_helper.h> +#include <drm/drm_mipi_dbi.h> +#include <drm/drm_rect.h> +#include <drm/drm_vblank.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) +{ + 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; + + drm_fb_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_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 void st7586_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect) +{ + struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev); + struct mipi_dbi *dbi = &dbidev->dbi; + int start, end, idx, ret = 0; + + if (!dbidev->enabled) + return; + + if (!drm_dev_enter(fb->dev, &idx)) + return; + + /* 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, fb, rect); + 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); + + drm_dev_exit(idx); +} + +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_crtc *crtc = &pipe->crtc; + struct drm_rect rect; + + if (drm_atomic_helper_damage_merged(old_state, state, &rect)) + st7586_fb_dirty(state->fb, &rect); + + if (crtc->state->event) { + spin_lock_irq(&crtc->dev->event_lock); + drm_crtc_send_vblank_event(crtc, crtc->state->event); + spin_unlock_irq(&crtc->dev->event_lock); + crtc->state->event = NULL; + } +} + +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_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_AREA, 0x00, 0x00, 0x00, 0x77); + mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE); + + msleep(100); + + dbidev->enabled = true; + st7586_fb_dirty(fb, &rect); + + 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"); + + if (!dbidev->enabled) + return; + + mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF); + dbidev->enabled = false; +} + +static const u32 st7586_formats[] = { + DRM_FORMAT_XRGB8888, +}; + +static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = { + .enable = st7586_pipe_enable, + .disable = st7586_pipe_disable, + .update = st7586_pipe_update, + .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb, +}; + +static const struct drm_display_mode st7586_mode = { + DRM_SIMPLE_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_ATOMIC, + .fops = &st7586_fops, + .release = mipi_dbi_release, + DRM_GEM_CMA_VMAP_DRIVER_OPS, + .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 = kzalloc(sizeof(*dbidev), GFP_KERNEL); + if (!dbidev) + return -ENOMEM; + + dbi = &dbidev->dbi; + drm = &dbidev->drm; + ret = devm_drm_dev_init(dev, drm, &st7586_driver); + if (ret) { + kfree(dbidev); + return ret; + } + + drm_mode_config_init(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)) { + DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n"); + return PTR_ERR(dbi->reset); + } + + a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW); + if (IS_ERR(a0)) { + DRM_DEV_ERROR(dev, "Failed to get gpio 'a0'\n"); + return PTR_ERR(a0); + } + + 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_generic_setup(drm, 0); + + return 0; +} + +static int st7586_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 st7586_shutdown(struct spi_device *spi) +{ + drm_atomic_helper_shutdown(spi_get_drvdata(spi)); +} + +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, + .remove = st7586_remove, + .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"); |