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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * DRM driver for Sitronix ST7586 panels4 *5 * Copyright 2017 David Lechner <david@lechnology.com>6 */7 8#include <linux/delay.h>9#include <linux/gpio/consumer.h>10#include <linux/module.h>11#include <linux/property.h>12#include <linux/spi/spi.h>13#include <video/mipi_display.h>14 15#include <drm/drm_atomic_helper.h>16#include <drm/drm_damage_helper.h>17#include <drm/drm_drv.h>18#include <drm/drm_fb_dma_helper.h>19#include <drm/drm_fbdev_dma.h>20#include <drm/drm_format_helper.h>21#include <drm/drm_framebuffer.h>22#include <drm/drm_gem_atomic_helper.h>23#include <drm/drm_gem_dma_helper.h>24#include <drm/drm_gem_framebuffer_helper.h>25#include <drm/drm_managed.h>26#include <drm/drm_mipi_dbi.h>27#include <drm/drm_rect.h>28 29/* controller-specific commands */30#define ST7586_DISP_MODE_GRAY 0x3831#define ST7586_DISP_MODE_MONO 0x3932#define ST7586_ENABLE_DDRAM 0x3a33#define ST7586_SET_DISP_DUTY 0xb034#define ST7586_SET_PART_DISP 0xb435#define ST7586_SET_NLINE_INV 0xb536#define ST7586_SET_VOP 0xc037#define ST7586_SET_BIAS_SYSTEM 0xc338#define ST7586_SET_BOOST_LEVEL 0xc439#define ST7586_SET_VOP_OFFSET 0xc740#define ST7586_ENABLE_ANALOG 0xd041#define ST7586_AUTO_READ_CTRL 0xd742#define ST7586_OTP_RW_CTRL 0xe043#define ST7586_OTP_CTRL_OUT 0xe144#define ST7586_OTP_READ 0xe345 46#define ST7586_DISP_CTRL_MX BIT(6)47#define ST7586_DISP_CTRL_MY BIT(7)48 49/*50 * The ST7586 controller has an unusual pixel format where 2bpp grayscale is51 * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd52 * pixel using only 2 bits.53 *54 * | D7 | D6 | D5 || | || 2bpp |55 * | (D4) | (D3) | (D2) || D1 | D0 || GRAY |56 * +------+------+------++------+------++------+57 * | 1 | 1 | 1 || 1 | 1 || 0 0 | black58 * | 1 | 0 | 0 || 1 | 0 || 0 1 | dark gray59 * | 0 | 1 | 0 || 0 | 1 || 1 0 | light gray60 * | 0 | 0 | 0 || 0 | 0 || 1 1 | white61 */62 63static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };64 65static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,66 struct drm_framebuffer *fb,67 struct drm_rect *clip,68 struct drm_format_conv_state *fmtcnv_state)69{70 size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);71 unsigned int x, y;72 u8 *src, *buf, val;73 struct iosys_map dst_map, vmap;74 75 buf = kmalloc(len, GFP_KERNEL);76 if (!buf)77 return;78 79 iosys_map_set_vaddr(&dst_map, buf);80 iosys_map_set_vaddr(&vmap, vaddr);81 drm_fb_xrgb8888_to_gray8(&dst_map, NULL, &vmap, fb, clip, fmtcnv_state);82 src = buf;83 84 for (y = clip->y1; y < clip->y2; y++) {85 for (x = clip->x1; x < clip->x2; x += 3) {86 val = st7586_lookup[*src++ >> 6] << 5;87 val |= st7586_lookup[*src++ >> 6] << 2;88 val |= st7586_lookup[*src++ >> 6] >> 1;89 *dst++ = val;90 }91 }92 93 kfree(buf);94}95 96static int st7586_buf_copy(void *dst, struct iosys_map *src, struct drm_framebuffer *fb,97 struct drm_rect *clip, struct drm_format_conv_state *fmtcnv_state)98{99 int ret;100 101 ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);102 if (ret)103 return ret;104 105 st7586_xrgb8888_to_gray332(dst, src->vaddr, fb, clip, fmtcnv_state);106 107 drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);108 109 return 0;110}111 112static void st7586_fb_dirty(struct iosys_map *src, struct drm_framebuffer *fb,113 struct drm_rect *rect, struct drm_format_conv_state *fmtcnv_state)114{115 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);116 struct mipi_dbi *dbi = &dbidev->dbi;117 int start, end, ret = 0;118 119 /* 3 pixels per byte, so grow clip to nearest multiple of 3 */120 rect->x1 = rounddown(rect->x1, 3);121 rect->x2 = roundup(rect->x2, 3);122 123 DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));124 125 ret = st7586_buf_copy(dbidev->tx_buf, src, fb, rect, fmtcnv_state);126 if (ret)127 goto err_msg;128 129 /* Pixels are packed 3 per byte */130 start = rect->x1 / 3;131 end = rect->x2 / 3;132 133 mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS,134 (start >> 8) & 0xFF, start & 0xFF,135 (end >> 8) & 0xFF, (end - 1) & 0xFF);136 mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS,137 (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF,138 (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF);139 140 ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START,141 (u8 *)dbidev->tx_buf,142 (end - start) * (rect->y2 - rect->y1));143err_msg:144 if (ret)145 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);146}147 148static void st7586_pipe_update(struct drm_simple_display_pipe *pipe,149 struct drm_plane_state *old_state)150{151 struct drm_plane_state *state = pipe->plane.state;152 struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);153 struct drm_framebuffer *fb = state->fb;154 struct drm_rect rect;155 int idx;156 157 if (!pipe->crtc.state->active)158 return;159 160 if (!drm_dev_enter(fb->dev, &idx))161 return;162 163 if (drm_atomic_helper_damage_merged(old_state, state, &rect))164 st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect,165 &shadow_plane_state->fmtcnv_state);166 167 drm_dev_exit(idx);168}169 170static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,171 struct drm_crtc_state *crtc_state,172 struct drm_plane_state *plane_state)173{174 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);175 struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);176 struct drm_framebuffer *fb = plane_state->fb;177 struct mipi_dbi *dbi = &dbidev->dbi;178 struct drm_rect rect = {179 .x1 = 0,180 .x2 = fb->width,181 .y1 = 0,182 .y2 = fb->height,183 };184 int idx, ret;185 u8 addr_mode;186 187 if (!drm_dev_enter(pipe->crtc.dev, &idx))188 return;189 190 DRM_DEBUG_KMS("\n");191 192 ret = mipi_dbi_poweron_reset(dbidev);193 if (ret)194 goto out_exit;195 196 mipi_dbi_command(dbi, ST7586_AUTO_READ_CTRL, 0x9f);197 mipi_dbi_command(dbi, ST7586_OTP_RW_CTRL, 0x00);198 199 msleep(10);200 201 mipi_dbi_command(dbi, ST7586_OTP_READ);202 203 msleep(20);204 205 mipi_dbi_command(dbi, ST7586_OTP_CTRL_OUT);206 mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);207 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);208 209 msleep(50);210 211 mipi_dbi_command(dbi, ST7586_SET_VOP_OFFSET, 0x00);212 mipi_dbi_command(dbi, ST7586_SET_VOP, 0xe3, 0x00);213 mipi_dbi_command(dbi, ST7586_SET_BIAS_SYSTEM, 0x02);214 mipi_dbi_command(dbi, ST7586_SET_BOOST_LEVEL, 0x04);215 mipi_dbi_command(dbi, ST7586_ENABLE_ANALOG, 0x1d);216 mipi_dbi_command(dbi, ST7586_SET_NLINE_INV, 0x00);217 mipi_dbi_command(dbi, ST7586_DISP_MODE_GRAY);218 mipi_dbi_command(dbi, ST7586_ENABLE_DDRAM, 0x02);219 220 switch (dbidev->rotation) {221 default:222 addr_mode = 0x00;223 break;224 case 90:225 addr_mode = ST7586_DISP_CTRL_MY;226 break;227 case 180:228 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;229 break;230 case 270:231 addr_mode = ST7586_DISP_CTRL_MX;232 break;233 }234 mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);235 236 mipi_dbi_command(dbi, ST7586_SET_DISP_DUTY, 0x7f);237 mipi_dbi_command(dbi, ST7586_SET_PART_DISP, 0xa0);238 mipi_dbi_command(dbi, MIPI_DCS_SET_PARTIAL_ROWS, 0x00, 0x00, 0x00, 0x77);239 mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE);240 241 msleep(100);242 243 st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect,244 &shadow_plane_state->fmtcnv_state);245 246 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);247out_exit:248 drm_dev_exit(idx);249}250 251static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)252{253 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);254 255 /*256 * This callback is not protected by drm_dev_enter/exit since we want to257 * turn off the display on regular driver unload. It's highly unlikely258 * that the underlying SPI controller is gone should this be called after259 * unplug.260 */261 262 DRM_DEBUG_KMS("\n");263 264 mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF);265}266 267static const u32 st7586_formats[] = {268 DRM_FORMAT_XRGB8888,269};270 271static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {272 .mode_valid = mipi_dbi_pipe_mode_valid,273 .enable = st7586_pipe_enable,274 .disable = st7586_pipe_disable,275 .update = st7586_pipe_update,276 .begin_fb_access = mipi_dbi_pipe_begin_fb_access,277 .end_fb_access = mipi_dbi_pipe_end_fb_access,278 .reset_plane = mipi_dbi_pipe_reset_plane,279 .duplicate_plane_state = mipi_dbi_pipe_duplicate_plane_state,280 .destroy_plane_state = mipi_dbi_pipe_destroy_plane_state,281};282 283static const struct drm_display_mode st7586_mode = {284 DRM_SIMPLE_MODE(178, 128, 37, 27),285};286 287DEFINE_DRM_GEM_DMA_FOPS(st7586_fops);288 289static const struct drm_driver st7586_driver = {290 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,291 .fops = &st7586_fops,292 DRM_GEM_DMA_DRIVER_OPS_VMAP,293 .debugfs_init = mipi_dbi_debugfs_init,294 .name = "st7586",295 .desc = "Sitronix ST7586",296 .date = "20170801",297 .major = 1,298 .minor = 0,299};300 301static const struct of_device_id st7586_of_match[] = {302 { .compatible = "lego,ev3-lcd" },303 {},304};305MODULE_DEVICE_TABLE(of, st7586_of_match);306 307static const struct spi_device_id st7586_id[] = {308 { "ev3-lcd", 0 },309 { },310};311MODULE_DEVICE_TABLE(spi, st7586_id);312 313static int st7586_probe(struct spi_device *spi)314{315 struct device *dev = &spi->dev;316 struct mipi_dbi_dev *dbidev;317 struct drm_device *drm;318 struct mipi_dbi *dbi;319 struct gpio_desc *a0;320 u32 rotation = 0;321 size_t bufsize;322 int ret;323 324 dbidev = devm_drm_dev_alloc(dev, &st7586_driver,325 struct mipi_dbi_dev, drm);326 if (IS_ERR(dbidev))327 return PTR_ERR(dbidev);328 329 dbi = &dbidev->dbi;330 drm = &dbidev->drm;331 332 bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay;333 334 dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);335 if (IS_ERR(dbi->reset))336 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");337 338 a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);339 if (IS_ERR(a0))340 return dev_err_probe(dev, PTR_ERR(a0), "Failed to get GPIO 'a0'\n");341 342 device_property_read_u32(dev, "rotation", &rotation);343 344 ret = mipi_dbi_spi_init(spi, dbi, a0);345 if (ret)346 return ret;347 348 /* Cannot read from this controller via SPI */349 dbi->read_commands = NULL;350 351 ret = mipi_dbi_dev_init_with_formats(dbidev, &st7586_pipe_funcs,352 st7586_formats, ARRAY_SIZE(st7586_formats),353 &st7586_mode, rotation, bufsize);354 if (ret)355 return ret;356 357 /*358 * we are using 8-bit data, so we are not actually swapping anything,359 * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the360 * right thing and not use 16-bit transfers (which results in swapped361 * bytes on little-endian systems and causes out of order data to be362 * sent to the display).363 */364 dbi->swap_bytes = true;365 366 drm_mode_config_reset(drm);367 368 ret = drm_dev_register(drm, 0);369 if (ret)370 return ret;371 372 spi_set_drvdata(spi, drm);373 374 drm_fbdev_dma_setup(drm, 0);375 376 return 0;377}378 379static void st7586_remove(struct spi_device *spi)380{381 struct drm_device *drm = spi_get_drvdata(spi);382 383 drm_dev_unplug(drm);384 drm_atomic_helper_shutdown(drm);385}386 387static void st7586_shutdown(struct spi_device *spi)388{389 drm_atomic_helper_shutdown(spi_get_drvdata(spi));390}391 392static struct spi_driver st7586_spi_driver = {393 .driver = {394 .name = "st7586",395 .of_match_table = st7586_of_match,396 },397 .id_table = st7586_id,398 .probe = st7586_probe,399 .remove = st7586_remove,400 .shutdown = st7586_shutdown,401};402module_spi_driver(st7586_spi_driver);403 404MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");405MODULE_AUTHOR("David Lechner <david@lechnology.com>");406MODULE_LICENSE("GPL");407