drivers/gpu/drm/tegra/rgb.c

   1 /*
   2  * Copyright (C) 2012 Avionic Design GmbH
   3  * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  */
   9
  10 #include <linux/clk.h>
  11
  12 #include "drm.h"
  13 #include "dc.h"
  14
  15 struct tegra_rgb {
  16         struct tegra_output output;
  17         struct tegra_dc *dc;
  18         bool enabled;
  19
  20         struct clk *clk_parent;
  21         struct clk *clk;
  22 };
  23
  24 static inline struct tegra_rgb *to_rgb(struct tegra_output *output)
  25 {
  26         return container_of(output, struct tegra_rgb, output);
  27 }
  28
  29 struct reg_entry {
  30         unsigned long offset;
  31         unsigned long value;
  32 };
  33
  34 static const struct reg_entry rgb_enable[] = {
  35         { DC_COM_PIN_OUTPUT_ENABLE(0),   0x00000000 },
  36         { DC_COM_PIN_OUTPUT_ENABLE(1),   0x00000000 },
  37         { DC_COM_PIN_OUTPUT_ENABLE(2),   0x00000000 },
  38         { DC_COM_PIN_OUTPUT_ENABLE(3),   0x00000000 },
  39         { DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
  40         { DC_COM_PIN_OUTPUT_POLARITY(1), 0x01000000 },
  41         { DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
  42         { DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
  43         { DC_COM_PIN_OUTPUT_DATA(0),     0x00000000 },
  44         { DC_COM_PIN_OUTPUT_DATA(1),     0x00000000 },
  45         { DC_COM_PIN_OUTPUT_DATA(2),     0x00000000 },
  46         { DC_COM_PIN_OUTPUT_DATA(3),     0x00000000 },
  47         { DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
  48         { DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
  49         { DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
  50         { DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
  51         { DC_COM_PIN_OUTPUT_SELECT(4),   0x00210222 },
  52         { DC_COM_PIN_OUTPUT_SELECT(5),   0x00002200 },
  53         { DC_COM_PIN_OUTPUT_SELECT(6),   0x00020000 },
  54 };
  55
  56 static const struct reg_entry rgb_disable[] = {
  57         { DC_COM_PIN_OUTPUT_SELECT(6),   0x00000000 },
  58         { DC_COM_PIN_OUTPUT_SELECT(5),   0x00000000 },
  59         { DC_COM_PIN_OUTPUT_SELECT(4),   0x00000000 },
  60         { DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
  61         { DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
  62         { DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
  63         { DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
  64         { DC_COM_PIN_OUTPUT_DATA(3),     0xaaaaaaaa },
  65         { DC_COM_PIN_OUTPUT_DATA(2),     0xaaaaaaaa },
  66         { DC_COM_PIN_OUTPUT_DATA(1),     0xaaaaaaaa },
  67         { DC_COM_PIN_OUTPUT_DATA(0),     0xaaaaaaaa },
  68         { DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
  69         { DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
  70         { DC_COM_PIN_OUTPUT_POLARITY(1), 0x00000000 },
  71         { DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
  72         { DC_COM_PIN_OUTPUT_ENABLE(3),   0x55555555 },
  73         { DC_COM_PIN_OUTPUT_ENABLE(2),   0x55555555 },
  74         { DC_COM_PIN_OUTPUT_ENABLE(1),   0x55150005 },
  75         { DC_COM_PIN_OUTPUT_ENABLE(0),   0x55555555 },
  76 };
  77
  78 static void tegra_dc_write_regs(struct tegra_dc *dc,
  79                                 const struct reg_entry *table,
  80                                 unsigned int num)
  81 {
  82         unsigned int i;
  83
  84         for (i = 0; i < num; i++)
  85                 tegra_dc_writel(dc, table[i].value, table[i].offset);
  86 }
  87
  88 static int tegra_output_rgb_enable(struct tegra_output *output)
  89 {
  90         struct tegra_rgb *rgb = to_rgb(output);
  91         unsigned long value;
  92
  93         if (rgb->enabled)
  94                 return 0;
  95
  96         tegra_dc_write_regs(rgb->dc, rgb_enable, ARRAY_SIZE(rgb_enable));
  97
  98         value = DE_SELECT_ACTIVE | DE_CONTROL_NORMAL;
  99         tegra_dc_writel(rgb->dc, value, DC_DISP_DATA_ENABLE_OPTIONS);
 100
 101         /* XXX: parameterize? */
 102         value = tegra_dc_readl(rgb->dc, DC_COM_PIN_OUTPUT_POLARITY(1));
 103         value &= ~LVS_OUTPUT_POLARITY_LOW;
 104         value &= ~LHS_OUTPUT_POLARITY_LOW;
 105         tegra_dc_writel(rgb->dc, value, DC_COM_PIN_OUTPUT_POLARITY(1));
 106
 107         /* XXX: parameterize? */
 108         value = DISP_DATA_FORMAT_DF1P1C | DISP_ALIGNMENT_MSB |
 109                 DISP_ORDER_RED_BLUE;
 110         tegra_dc_writel(rgb->dc, value, DC_DISP_DISP_INTERFACE_CONTROL);
 111
 112         /* XXX: parameterize? */
 113         value = SC0_H_QUALIFIER_NONE | SC1_H_QUALIFIER_NONE;
 114         tegra_dc_writel(rgb->dc, value, DC_DISP_SHIFT_CLOCK_OPTIONS);
 115
 116         value = tegra_dc_readl(rgb->dc, DC_CMD_DISPLAY_COMMAND);
 117         value &= ~DISP_CTRL_MODE_MASK;
 118         value |= DISP_CTRL_MODE_C_DISPLAY;
 119         tegra_dc_writel(rgb->dc, value, DC_CMD_DISPLAY_COMMAND);
 120
 121         value = tegra_dc_readl(rgb->dc, DC_CMD_DISPLAY_POWER_CONTROL);
 122         value |= PW0_ENABLE | PW1_ENABLE | PW2_ENABLE | PW3_ENABLE |
 123                  PW4_ENABLE | PM0_ENABLE | PM1_ENABLE;
 124         tegra_dc_writel(rgb->dc, value, DC_CMD_DISPLAY_POWER_CONTROL);
 125
 126         tegra_dc_writel(rgb->dc, GENERAL_ACT_REQ << 8, DC_CMD_STATE_CONTROL);
 127         tegra_dc_writel(rgb->dc, GENERAL_ACT_REQ, DC_CMD_STATE_CONTROL);
 128
 129         rgb->enabled = true;
 130
 131         return 0;
 132 }
 133
 134 static int tegra_output_rgb_disable(struct tegra_output *output)
 135 {
 136         struct tegra_rgb *rgb = to_rgb(output);
 137         unsigned long value;
 138
 139         if (!rgb->enabled)
 140                 return 0;
 141
 142         value = tegra_dc_readl(rgb->dc, DC_CMD_DISPLAY_POWER_CONTROL);
 143         value &= ~(PW0_ENABLE | PW1_ENABLE | PW2_ENABLE | PW3_ENABLE |
 144                    PW4_ENABLE | PM0_ENABLE | PM1_ENABLE);
 145         tegra_dc_writel(rgb->dc, value, DC_CMD_DISPLAY_POWER_CONTROL);
 146
 147         value = tegra_dc_readl(rgb->dc, DC_CMD_DISPLAY_COMMAND);
 148         value &= ~DISP_CTRL_MODE_MASK;
 149         tegra_dc_writel(rgb->dc, value, DC_CMD_DISPLAY_COMMAND);
 150
 151         tegra_dc_writel(rgb->dc, GENERAL_ACT_REQ << 8, DC_CMD_STATE_CONTROL);
 152         tegra_dc_writel(rgb->dc, GENERAL_ACT_REQ, DC_CMD_STATE_CONTROL);
 153
 154         tegra_dc_write_regs(rgb->dc, rgb_disable, ARRAY_SIZE(rgb_disable));
 155
 156         rgb->enabled = false;
 157
 158         return 0;
 159 }
 160
 161 static int tegra_output_rgb_setup_clock(struct tegra_output *output,
 162                                         struct clk *clk, unsigned long pclk,
 163                                         unsigned int *div)
 164 {
 165         struct tegra_rgb *rgb = to_rgb(output);
 166         int err;
 167
 168         err = clk_set_parent(clk, rgb->clk_parent);
 169         if (err < 0) {
 170                 dev_err(output->dev, "failed to set parent: %d\n", err);
 171                 return err;
 172         }
 173
 174         /*
 175          * We may not want to change the frequency of the parent clock, since
 176          * it may be a parent for other peripherals. This is due to the fact
 177          * that on Tegra20 there's only a single clock dedicated to display
 178          * (pll_d_out0), whereas later generations have a second one that can
 179          * be used to independently drive a second output (pll_d2_out0).
 180          *
 181          * As a way to support multiple outputs on Tegra20 as well, pll_p is
 182          * typically used as the parent clock for the display controllers.
 183          * But this comes at a cost: pll_p is the parent of several other
 184          * peripherals, so its frequency shouldn't change out of the blue.
 185          *
 186          * The best we can do at this point is to use the shift clock divider
 187          * and hope that the desired frequency can be matched (or at least
 188          * matched sufficiently close that the panel will still work).
 189          */
 190
 191         *div = ((clk_get_rate(clk) * 2) / pclk) - 2;
 192
 193         return 0;
 194 }
 195
 196 static int tegra_output_rgb_check_mode(struct tegra_output *output,
 197                                        struct drm_display_mode *mode,
 198                                        enum drm_mode_status *status)
 199 {
 200         /*
 201          * FIXME: For now, always assume that the mode is okay. There are
 202          * unresolved issues with clk_round_rate(), which doesn't always
 203          * reliably report whether a frequency can be set or not.
 204          */
 205
 206         *status = MODE_OK;
 207
 208         return 0;
 209 }
 210
 211 static const struct tegra_output_ops rgb_ops = {
 212         .enable = tegra_output_rgb_enable,
 213         .disable = tegra_output_rgb_disable,
 214         .setup_clock = tegra_output_rgb_setup_clock,
 215         .check_mode = tegra_output_rgb_check_mode,
 216 };
 217
 218 int tegra_dc_rgb_probe(struct tegra_dc *dc)
 219 {
 220         struct device_node *np;
 221         struct tegra_rgb *rgb;
 222         int err;
 223
 224         np = of_get_child_by_name(dc->dev->of_node, "rgb");
 225         if (!np || !of_device_is_available(np))
 226                 return -ENODEV;
 227
 228         rgb = devm_kzalloc(dc->dev, sizeof(*rgb), GFP_KERNEL);
 229         if (!rgb)
 230                 return -ENOMEM;
 231
 232         rgb->output.dev = dc->dev;
 233         rgb->output.of_node = np;
 234         rgb->dc = dc;
 235
 236         err = tegra_output_probe(&rgb->output);
 237         if (err < 0)
 238                 return err;
 239
 240         rgb->clk = devm_clk_get(dc->dev, NULL);
 241         if (IS_ERR(rgb->clk)) {
 242                 dev_err(dc->dev, "failed to get clock\n");
 243                 return PTR_ERR(rgb->clk);
 244         }
 245
 246         rgb->clk_parent = devm_clk_get(dc->dev, "parent");
 247         if (IS_ERR(rgb->clk_parent)) {
 248                 dev_err(dc->dev, "failed to get parent clock\n");
 249                 return PTR_ERR(rgb->clk_parent);
 250         }
 251
 252         err = clk_set_parent(rgb->clk, rgb->clk_parent);
 253         if (err < 0) {
 254                 dev_err(dc->dev, "failed to set parent clock: %d\n", err);
 255                 return err;
 256         }
 257
 258         dc->rgb = &rgb->output;
 259
 260         return 0;
 261 }
 262
 263 int tegra_dc_rgb_remove(struct tegra_dc *dc)
 264 {
 265         int err;
 266
 267         if (!dc->rgb)
 268                 return 0;
 269
 270         err = tegra_output_remove(dc->rgb);
 271         if (err < 0)
 272                 return err;
 273
 274         return 0;
 275 }
 276
 277 int tegra_dc_rgb_init(struct drm_device *drm, struct tegra_dc *dc)
 278 {
 279         struct tegra_rgb *rgb = to_rgb(dc->rgb);
 280         int err;
 281
 282         if (!dc->rgb)
 283                 return -ENODEV;
 284
 285         rgb->output.type = TEGRA_OUTPUT_RGB;
 286         rgb->output.ops = &rgb_ops;
 287
 288         err = tegra_output_init(dc->base.dev, &rgb->output);
 289         if (err < 0) {
 290                 dev_err(dc->dev, "output setup failed: %d\n", err);
 291                 return err;
 292         }
 293
 294         /*
 295          * By default, outputs can be associated with each display controller.
 296          * RGB outputs are an exception, so we make sure they can be attached
 297          * to only their parent display controller.
 298          */
 299         rgb->output.encoder.possible_crtcs = drm_crtc_mask(&dc->base);
 300
 301         return 0;
 302 }
 303
 304 int tegra_dc_rgb_exit(struct tegra_dc *dc)
 305 {
 306         if (dc->rgb) {
 307                 int err;
 308
 309                 err = tegra_output_disable(dc->rgb);
 310                 if (err < 0) {
 311                         dev_err(dc->dev, "output failed to disable: %d\n", err);
 312                         return err;
 313                 }
 314
 315                 err = tegra_output_exit(dc->rgb);
 316                 if (err < 0) {
 317                         dev_err(dc->dev, "output cleanup failed: %d\n", err);
 318                         return err;
 319                 }
 320
 321                 dc->rgb = NULL;
 322         }
 323
 324         return 0;
 325 }