drivers/video/fbdev/omap2/dss/sdi.c

   1 /*
   2  * linux/drivers/video/omap2/dss/sdi.c
   3  *
   4  * Copyright (C) 2009 Nokia Corporation
   5  * Author: Tomi Valkeinen <tomi.valkeinen@nokia.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along with
  17  * this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #define DSS_SUBSYS_NAME "SDI"
  21
  22 #include <linux/kernel.h>
  23 #include <linux/delay.h>
  24 #include <linux/err.h>
  25 #include <linux/regulator/consumer.h>
  26 #include <linux/export.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/string.h>
  29 #include <linux/of.h>
  30
  31 #include <video/omapdss.h>
  32 #include "dss.h"
  33
  34 static struct {
  35         struct platform_device *pdev;
  36
  37         bool update_enabled;
  38         struct regulator *vdds_sdi_reg;
  39
  40         struct dss_lcd_mgr_config mgr_config;
  41         struct omap_video_timings timings;
  42         int datapairs;
  43
  44         struct omap_dss_device output;
  45
  46         bool port_initialized;
  47 } sdi;
  48
  49 struct sdi_clk_calc_ctx {
  50         unsigned long pck_min, pck_max;
  51
  52         unsigned long fck;
  53         struct dispc_clock_info dispc_cinfo;
  54 };
  55
  56 static bool dpi_calc_dispc_cb(int lckd, int pckd, unsigned long lck,
  57                 unsigned long pck, void *data)
  58 {
  59         struct sdi_clk_calc_ctx *ctx = data;
  60
  61         ctx->dispc_cinfo.lck_div = lckd;
  62         ctx->dispc_cinfo.pck_div = pckd;
  63         ctx->dispc_cinfo.lck = lck;
  64         ctx->dispc_cinfo.pck = pck;
  65
  66         return true;
  67 }
  68
  69 static bool dpi_calc_dss_cb(unsigned long fck, void *data)
  70 {
  71         struct sdi_clk_calc_ctx *ctx = data;
  72
  73         ctx->fck = fck;
  74
  75         return dispc_div_calc(fck, ctx->pck_min, ctx->pck_max,
  76                         dpi_calc_dispc_cb, ctx);
  77 }
  78
  79 static int sdi_calc_clock_div(unsigned long pclk,
  80                 unsigned long *fck,
  81                 struct dispc_clock_info *dispc_cinfo)
  82 {
  83         int i;
  84         struct sdi_clk_calc_ctx ctx;
  85
  86         /*
  87          * DSS fclk gives us very few possibilities, so finding a good pixel
  88          * clock may not be possible. We try multiple times to find the clock,
  89          * each time widening the pixel clock range we look for, up to
  90          * +/- 1MHz.
  91          */
  92
  93         for (i = 0; i < 10; ++i) {
  94                 bool ok;
  95
  96                 memset(&ctx, 0, sizeof(ctx));
  97                 if (pclk > 1000 * i * i * i)
  98                         ctx.pck_min = max(pclk - 1000 * i * i * i, 0lu);
  99                 else
 100                         ctx.pck_min = 0;
 101                 ctx.pck_max = pclk + 1000 * i * i * i;
 102
 103                 ok = dss_div_calc(pclk, ctx.pck_min, dpi_calc_dss_cb, &ctx);
 104                 if (ok) {
 105                         *fck = ctx.fck;
 106                         *dispc_cinfo = ctx.dispc_cinfo;
 107                         return 0;
 108                 }
 109         }
 110
 111         return -EINVAL;
 112 }
 113
 114 static void sdi_config_lcd_manager(struct omap_dss_device *dssdev)
 115 {
 116         struct omap_overlay_manager *mgr = sdi.output.manager;
 117
 118         sdi.mgr_config.io_pad_mode = DSS_IO_PAD_MODE_BYPASS;
 119
 120         sdi.mgr_config.stallmode = false;
 121         sdi.mgr_config.fifohandcheck = false;
 122
 123         sdi.mgr_config.video_port_width = 24;
 124         sdi.mgr_config.lcden_sig_polarity = 1;
 125
 126         dss_mgr_set_lcd_config(mgr, &sdi.mgr_config);
 127 }
 128
 129 static int sdi_display_enable(struct omap_dss_device *dssdev)
 130 {
 131         struct omap_dss_device *out = &sdi.output;
 132         struct omap_video_timings *t = &sdi.timings;
 133         unsigned long fck;
 134         struct dispc_clock_info dispc_cinfo;
 135         unsigned long pck;
 136         int r;
 137
 138         if (out == NULL || out->manager == NULL) {
 139                 DSSERR("failed to enable display: no output/manager\n");
 140                 return -ENODEV;
 141         }
 142
 143         r = regulator_enable(sdi.vdds_sdi_reg);
 144         if (r)
 145                 goto err_reg_enable;
 146
 147         r = dispc_runtime_get();
 148         if (r)
 149                 goto err_get_dispc;
 150
 151         /* 15.5.9.1.2 */
 152         t->data_pclk_edge = OMAPDSS_DRIVE_SIG_RISING_EDGE;
 153         t->sync_pclk_edge = OMAPDSS_DRIVE_SIG_RISING_EDGE;
 154
 155         r = sdi_calc_clock_div(t->pixelclock, &fck, &dispc_cinfo);
 156         if (r)
 157                 goto err_calc_clock_div;
 158
 159         sdi.mgr_config.clock_info = dispc_cinfo;
 160
 161         pck = fck / dispc_cinfo.lck_div / dispc_cinfo.pck_div;
 162
 163         if (pck != t->pixelclock) {
 164                 DSSWARN("Could not find exact pixel clock. Requested %d Hz, got %lu Hz\n",
 165                         t->pixelclock, pck);
 166
 167                 t->pixelclock = pck;
 168         }
 169
 170
 171         dss_mgr_set_timings(out->manager, t);
 172
 173         r = dss_set_fck_rate(fck);
 174         if (r)
 175                 goto err_set_dss_clock_div;
 176
 177         sdi_config_lcd_manager(dssdev);
 178
 179         /*
 180          * LCLK and PCLK divisors are located in shadow registers, and we
 181          * normally write them to DISPC registers when enabling the output.
 182          * However, SDI uses pck-free as source clock for its PLL, and pck-free
 183          * is affected by the divisors. And as we need the PLL before enabling
 184          * the output, we need to write the divisors early.
 185          *
 186          * It seems just writing to the DISPC register is enough, and we don't
 187          * need to care about the shadow register mechanism for pck-free. The
 188          * exact reason for this is unknown.
 189          */
 190         dispc_mgr_set_clock_div(out->manager->id, &sdi.mgr_config.clock_info);
 191
 192         dss_sdi_init(sdi.datapairs);
 193         r = dss_sdi_enable();
 194         if (r)
 195                 goto err_sdi_enable;
 196         mdelay(2);
 197
 198         r = dss_mgr_enable(out->manager);
 199         if (r)
 200                 goto err_mgr_enable;
 201
 202         return 0;
 203
 204 err_mgr_enable:
 205         dss_sdi_disable();
 206 err_sdi_enable:
 207 err_set_dss_clock_div:
 208 err_calc_clock_div:
 209         dispc_runtime_put();
 210 err_get_dispc:
 211         regulator_disable(sdi.vdds_sdi_reg);
 212 err_reg_enable:
 213         return r;
 214 }
 215
 216 static void sdi_display_disable(struct omap_dss_device *dssdev)
 217 {
 218         struct omap_overlay_manager *mgr = sdi.output.manager;
 219
 220         dss_mgr_disable(mgr);
 221
 222         dss_sdi_disable();
 223
 224         dispc_runtime_put();
 225
 226         regulator_disable(sdi.vdds_sdi_reg);
 227 }
 228
 229 static void sdi_set_timings(struct omap_dss_device *dssdev,
 230                 struct omap_video_timings *timings)
 231 {
 232         sdi.timings = *timings;
 233 }
 234
 235 static void sdi_get_timings(struct omap_dss_device *dssdev,
 236                 struct omap_video_timings *timings)
 237 {
 238         *timings = sdi.timings;
 239 }
 240
 241 static int sdi_check_timings(struct omap_dss_device *dssdev,
 242                         struct omap_video_timings *timings)
 243 {
 244         struct omap_overlay_manager *mgr = sdi.output.manager;
 245
 246         if (mgr && !dispc_mgr_timings_ok(mgr->id, timings))
 247                 return -EINVAL;
 248
 249         if (timings->pixelclock == 0)
 250                 return -EINVAL;
 251
 252         return 0;
 253 }
 254
 255 static void sdi_set_datapairs(struct omap_dss_device *dssdev, int datapairs)
 256 {
 257         sdi.datapairs = datapairs;
 258 }
 259
 260 static int sdi_init_regulator(void)
 261 {
 262         struct regulator *vdds_sdi;
 263
 264         if (sdi.vdds_sdi_reg)
 265                 return 0;
 266
 267         vdds_sdi = devm_regulator_get(&sdi.pdev->dev, "vdds_sdi");
 268         if (IS_ERR(vdds_sdi)) {
 269                 if (PTR_ERR(vdds_sdi) != -EPROBE_DEFER)
 270                         DSSERR("can't get VDDS_SDI regulator\n");
 271                 return PTR_ERR(vdds_sdi);
 272         }
 273
 274         sdi.vdds_sdi_reg = vdds_sdi;
 275
 276         return 0;
 277 }
 278
 279 static int sdi_connect(struct omap_dss_device *dssdev,
 280                 struct omap_dss_device *dst)
 281 {
 282         struct omap_overlay_manager *mgr;
 283         int r;
 284
 285         r = sdi_init_regulator();
 286         if (r)
 287                 return r;
 288
 289         mgr = omap_dss_get_overlay_manager(dssdev->dispc_channel);
 290         if (!mgr)
 291                 return -ENODEV;
 292
 293         r = dss_mgr_connect(mgr, dssdev);
 294         if (r)
 295                 return r;
 296
 297         r = omapdss_output_set_device(dssdev, dst);
 298         if (r) {
 299                 DSSERR("failed to connect output to new device: %s\n",
 300                                 dst->name);
 301                 dss_mgr_disconnect(mgr, dssdev);
 302                 return r;
 303         }
 304
 305         return 0;
 306 }
 307
 308 static void sdi_disconnect(struct omap_dss_device *dssdev,
 309                 struct omap_dss_device *dst)
 310 {
 311         WARN_ON(dst != dssdev->dst);
 312
 313         if (dst != dssdev->dst)
 314                 return;
 315
 316         omapdss_output_unset_device(dssdev);
 317
 318         if (dssdev->manager)
 319                 dss_mgr_disconnect(dssdev->manager, dssdev);
 320 }
 321
 322 static const struct omapdss_sdi_ops sdi_ops = {
 323         .connect = sdi_connect,
 324         .disconnect = sdi_disconnect,
 325
 326         .enable = sdi_display_enable,
 327         .disable = sdi_display_disable,
 328
 329         .check_timings = sdi_check_timings,
 330         .set_timings = sdi_set_timings,
 331         .get_timings = sdi_get_timings,
 332
 333         .set_datapairs = sdi_set_datapairs,
 334 };
 335
 336 static void sdi_init_output(struct platform_device *pdev)
 337 {
 338         struct omap_dss_device *out = &sdi.output;
 339
 340         out->dev = &pdev->dev;
 341         out->id = OMAP_DSS_OUTPUT_SDI;
 342         out->output_type = OMAP_DISPLAY_TYPE_SDI;
 343         out->name = "sdi.0";
 344         out->dispc_channel = OMAP_DSS_CHANNEL_LCD;
 345         out->ops.sdi = &sdi_ops;
 346         out->owner = THIS_MODULE;
 347
 348         omapdss_register_output(out);
 349 }
 350
 351 static void __exit sdi_uninit_output(struct platform_device *pdev)
 352 {
 353         struct omap_dss_device *out = &sdi.output;
 354
 355         omapdss_unregister_output(out);
 356 }
 357
 358 static int omap_sdi_probe(struct platform_device *pdev)
 359 {
 360         sdi.pdev = pdev;
 361
 362         sdi_init_output(pdev);
 363
 364         return 0;
 365 }
 366
 367 static int __exit omap_sdi_remove(struct platform_device *pdev)
 368 {
 369         sdi_uninit_output(pdev);
 370
 371         return 0;
 372 }
 373
 374 static struct platform_driver omap_sdi_driver = {
 375         .probe          = omap_sdi_probe,
 376         .remove         = __exit_p(omap_sdi_remove),
 377         .driver         = {
 378                 .name   = "omapdss_sdi",
 379                 .owner  = THIS_MODULE,
 380         },
 381 };
 382
 383 int __init sdi_init_platform_driver(void)
 384 {
 385         return platform_driver_register(&omap_sdi_driver);
 386 }
 387
 388 void __exit sdi_uninit_platform_driver(void)
 389 {
 390         platform_driver_unregister(&omap_sdi_driver);
 391 }
 392
 393 int __init sdi_init_port(struct platform_device *pdev, struct device_node *port)
 394 {
 395         struct device_node *ep;
 396         u32 datapairs;
 397         int r;
 398
 399         ep = omapdss_of_get_next_endpoint(port, NULL);
 400         if (!ep)
 401                 return 0;
 402
 403         r = of_property_read_u32(ep, "datapairs", &datapairs);
 404         if (r) {
 405                 DSSERR("failed to parse datapairs\n");
 406                 goto err_datapairs;
 407         }
 408
 409         sdi.datapairs = datapairs;
 410
 411         of_node_put(ep);
 412
 413         sdi.pdev = pdev;
 414
 415         sdi_init_output(pdev);
 416
 417         sdi.port_initialized = true;
 418
 419         return 0;
 420
 421 err_datapairs:
 422         of_node_put(ep);
 423
 424         return r;
 425 }
 426
 427 void __exit sdi_uninit_port(void)
 428 {
 429         if (!sdi.port_initialized)
 430                 return;
 431
 432         sdi_uninit_output(sdi.pdev);
 433 }