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/drm_atomic_helper.h>
  13 #include <drm/drm_panel.h>
  14
  15 #include "drm.h"
  16 #include "dc.h"
  17
  18 struct tegra_rgb {
  19         struct tegra_output output;
  20         struct tegra_dc *dc;
  21
  22         struct clk *clk_parent;
  23         struct clk *clk;
  24 };
  25
  26 static inline struct tegra_rgb *to_rgb(struct tegra_output *output)
  27 {
  28         return container_of(output, struct tegra_rgb, output);
  29 }
  30
  31 struct reg_entry {
  32         unsigned long offset;
  33         unsigned long value;
  34 };
  35
  36 static const struct reg_entry rgb_enable[] = {
  37         { DC_COM_PIN_OUTPUT_ENABLE(0),   0x00000000 },
  38         { DC_COM_PIN_OUTPUT_ENABLE(1),   0x00000000 },
  39         { DC_COM_PIN_OUTPUT_ENABLE(2),   0x00000000 },
  40         { DC_COM_PIN_OUTPUT_ENABLE(3),   0x00000000 },
  41         { DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
  42         { DC_COM_PIN_OUTPUT_POLARITY(1), 0x01000000 },
  43         { DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
  44         { DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
  45         { DC_COM_PIN_OUTPUT_DATA(0),     0x00000000 },
  46         { DC_COM_PIN_OUTPUT_DATA(1),     0x00000000 },
  47         { DC_COM_PIN_OUTPUT_DATA(2),     0x00000000 },
  48         { DC_COM_PIN_OUTPUT_DATA(3),     0x00000000 },
  49         { DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
  50         { DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
  51         { DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
  52         { DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
  53         { DC_COM_PIN_OUTPUT_SELECT(4),   0x00210222 },
  54         { DC_COM_PIN_OUTPUT_SELECT(5),   0x00002200 },
  55         { DC_COM_PIN_OUTPUT_SELECT(6),   0x00020000 },
  56 };
  57
  58 static const struct reg_entry rgb_disable[] = {
  59         { DC_COM_PIN_OUTPUT_SELECT(6),   0x00000000 },
  60         { DC_COM_PIN_OUTPUT_SELECT(5),   0x00000000 },
  61         { DC_COM_PIN_OUTPUT_SELECT(4),   0x00000000 },
  62         { DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
  63         { DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
  64         { DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
  65         { DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
  66         { DC_COM_PIN_OUTPUT_DATA(3),     0xaaaaaaaa },
  67         { DC_COM_PIN_OUTPUT_DATA(2),     0xaaaaaaaa },
  68         { DC_COM_PIN_OUTPUT_DATA(1),     0xaaaaaaaa },
  69         { DC_COM_PIN_OUTPUT_DATA(0),     0xaaaaaaaa },
  70         { DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
  71         { DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
  72         { DC_COM_PIN_OUTPUT_POLARITY(1), 0x00000000 },
  73         { DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
  74         { DC_COM_PIN_OUTPUT_ENABLE(3),   0x55555555 },
  75         { DC_COM_PIN_OUTPUT_ENABLE(2),   0x55555555 },
  76         { DC_COM_PIN_OUTPUT_ENABLE(1),   0x55150005 },
  77         { DC_COM_PIN_OUTPUT_ENABLE(0),   0x55555555 },
  78 };
  79
  80 static void tegra_dc_write_regs(struct tegra_dc *dc,
  81                                 const struct reg_entry *table,
  82                                 unsigned int num)
  83 {
  84         unsigned int i;
  85
  86         for (i = 0; i < num; i++)
  87                 tegra_dc_writel(dc, table[i].value, table[i].offset);
  88 }
  89
  90 static const struct drm_connector_funcs tegra_rgb_connector_funcs = {
  91         .reset = drm_atomic_helper_connector_reset,
  92         .detect = tegra_output_connector_detect,
  93         .fill_modes = drm_helper_probe_single_connector_modes,
  94         .destroy = tegra_output_connector_destroy,
  95         .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
  96         .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
  97 };
  98
  99 static enum drm_mode_status
 100 tegra_rgb_connector_mode_valid(struct drm_connector *connector,
 101                                struct drm_display_mode *mode)
 102 {
 103         /*
 104          * FIXME: For now, always assume that the mode is okay. There are
 105          * unresolved issues with clk_round_rate(), which doesn't always
 106          * reliably report whether a frequency can be set or not.
 107          */
 108         return MODE_OK;
 109 }
 110
 111 static const struct drm_connector_helper_funcs tegra_rgb_connector_helper_funcs = {
 112         .get_modes = tegra_output_connector_get_modes,
 113         .mode_valid = tegra_rgb_connector_mode_valid,
 114 };
 115
 116 static const struct drm_encoder_funcs tegra_rgb_encoder_funcs = {
 117         .destroy = tegra_output_encoder_destroy,
 118 };
 119
 120 static void tegra_rgb_encoder_disable(struct drm_encoder *encoder)
 121 {
 122         struct tegra_output *output = encoder_to_output(encoder);
 123         struct tegra_rgb *rgb = to_rgb(output);
 124
 125         if (output->panel)
 126                 drm_panel_disable(output->panel);
 127
 128         tegra_dc_write_regs(rgb->dc, rgb_disable, ARRAY_SIZE(rgb_disable));
 129         tegra_dc_commit(rgb->dc);
 130
 131         if (output->panel)
 132                 drm_panel_unprepare(output->panel);
 133 }
 134
 135 static void tegra_rgb_encoder_enable(struct drm_encoder *encoder)
 136 {
 137         struct tegra_output *output = encoder_to_output(encoder);
 138         struct tegra_rgb *rgb = to_rgb(output);
 139         u32 value;
 140
 141         if (output->panel)
 142                 drm_panel_prepare(output->panel);
 143
 144         tegra_dc_write_regs(rgb->dc, rgb_enable, ARRAY_SIZE(rgb_enable));
 145
 146         value = DE_SELECT_ACTIVE | DE_CONTROL_NORMAL;
 147         tegra_dc_writel(rgb->dc, value, DC_DISP_DATA_ENABLE_OPTIONS);
 148
 149         /* XXX: parameterize? */
 150         value = tegra_dc_readl(rgb->dc, DC_COM_PIN_OUTPUT_POLARITY(1));
 151         value &= ~LVS_OUTPUT_POLARITY_LOW;
 152         value &= ~LHS_OUTPUT_POLARITY_LOW;
 153         tegra_dc_writel(rgb->dc, value, DC_COM_PIN_OUTPUT_POLARITY(1));
 154
 155         /* XXX: parameterize? */
 156         value = DISP_DATA_FORMAT_DF1P1C | DISP_ALIGNMENT_MSB |
 157                 DISP_ORDER_RED_BLUE;
 158         tegra_dc_writel(rgb->dc, value, DC_DISP_DISP_INTERFACE_CONTROL);
 159
 160         /* XXX: parameterize? */
 161         value = SC0_H_QUALIFIER_NONE | SC1_H_QUALIFIER_NONE;
 162         tegra_dc_writel(rgb->dc, value, DC_DISP_SHIFT_CLOCK_OPTIONS);
 163
 164         tegra_dc_commit(rgb->dc);
 165
 166         if (output->panel)
 167                 drm_panel_enable(output->panel);
 168 }
 169
 170 static int
 171 tegra_rgb_encoder_atomic_check(struct drm_encoder *encoder,
 172                                struct drm_crtc_state *crtc_state,
 173                                struct drm_connector_state *conn_state)
 174 {
 175         struct tegra_output *output = encoder_to_output(encoder);
 176         struct tegra_dc *dc = to_tegra_dc(conn_state->crtc);
 177         unsigned long pclk = crtc_state->mode.clock * 1000;
 178         struct tegra_rgb *rgb = to_rgb(output);
 179         unsigned int div;
 180         int err;
 181
 182         /*
 183          * We may not want to change the frequency of the parent clock, since
 184          * it may be a parent for other peripherals. This is due to the fact
 185          * that on Tegra20 there's only a single clock dedicated to display
 186          * (pll_d_out0), whereas later generations have a second one that can
 187          * be used to independently drive a second output (pll_d2_out0).
 188          *
 189          * As a way to support multiple outputs on Tegra20 as well, pll_p is
 190          * typically used as the parent clock for the display controllers.
 191          * But this comes at a cost: pll_p is the parent of several other
 192          * peripherals, so its frequency shouldn't change out of the blue.
 193          *
 194          * The best we can do at this point is to use the shift clock divider
 195          * and hope that the desired frequency can be matched (or at least
 196          * matched sufficiently close that the panel will still work).
 197          */
 198         div = ((clk_get_rate(rgb->clk) * 2) / pclk) - 2;
 199         pclk = 0;
 200
 201         err = tegra_dc_state_setup_clock(dc, crtc_state, rgb->clk_parent,
 202                                          pclk, div);
 203         if (err < 0) {
 204                 dev_err(output->dev, "failed to setup CRTC state: %d\n", err);
 205                 return err;
 206         }
 207
 208         return err;
 209 }
 210
 211 static const struct drm_encoder_helper_funcs tegra_rgb_encoder_helper_funcs = {
 212         .disable = tegra_rgb_encoder_disable,
 213         .enable = tegra_rgb_encoder_enable,
 214         .atomic_check = tegra_rgb_encoder_atomic_check,
 215 };
 216
 217 int tegra_dc_rgb_probe(struct tegra_dc *dc)
 218 {
 219         struct device_node *np;
 220         struct tegra_rgb *rgb;
 221         int err;
 222
 223         np = of_get_child_by_name(dc->dev->of_node, "rgb");
 224         if (!np || !of_device_is_available(np))
 225                 return -ENODEV;
 226
 227         rgb = devm_kzalloc(dc->dev, sizeof(*rgb), GFP_KERNEL);
 228         if (!rgb)
 229                 return -ENOMEM;
 230
 231         rgb->output.dev = dc->dev;
 232         rgb->output.of_node = np;
 233         rgb->dc = dc;
 234
 235         err = tegra_output_probe(&rgb->output);
 236         if (err < 0)
 237                 return err;
 238
 239         rgb->clk = devm_clk_get(dc->dev, NULL);
 240         if (IS_ERR(rgb->clk)) {
 241                 dev_err(dc->dev, "failed to get clock\n");
 242                 return PTR_ERR(rgb->clk);
 243         }
 244
 245         rgb->clk_parent = devm_clk_get(dc->dev, "parent");
 246         if (IS_ERR(rgb->clk_parent)) {
 247                 dev_err(dc->dev, "failed to get parent clock\n");
 248                 return PTR_ERR(rgb->clk_parent);
 249         }
 250
 251         err = clk_set_parent(rgb->clk, rgb->clk_parent);
 252         if (err < 0) {
 253                 dev_err(dc->dev, "failed to set parent clock: %d\n", err);
 254                 return err;
 255         }
 256
 257         dc->rgb = &rgb->output;
 258
 259         return 0;
 260 }
 261
 262 int tegra_dc_rgb_remove(struct tegra_dc *dc)
 263 {
 264         if (!dc->rgb)
 265                 return 0;
 266
 267         tegra_output_remove(dc->rgb);
 268         dc->rgb = NULL;
 269
 270         return 0;
 271 }
 272
 273 int tegra_dc_rgb_init(struct drm_device *drm, struct tegra_dc *dc)
 274 {
 275         struct tegra_output *output = dc->rgb;
 276         int err;
 277
 278         if (!dc->rgb)
 279                 return -ENODEV;
 280
 281         drm_connector_init(drm, &output->connector, &tegra_rgb_connector_funcs,
 282                            DRM_MODE_CONNECTOR_LVDS);
 283         drm_connector_helper_add(&output->connector,
 284                                  &tegra_rgb_connector_helper_funcs);
 285         output->connector.dpms = DRM_MODE_DPMS_OFF;
 286
 287         drm_encoder_init(drm, &output->encoder, &tegra_rgb_encoder_funcs,
 288                          DRM_MODE_ENCODER_LVDS, NULL);
 289         drm_encoder_helper_add(&output->encoder,
 290                                &tegra_rgb_encoder_helper_funcs);
 291
 292         drm_connector_attach_encoder(&output->connector,
 293                                           &output->encoder);
 294         drm_connector_register(&output->connector);
 295
 296         err = tegra_output_init(drm, output);
 297         if (err < 0) {
 298                 dev_err(output->dev, "failed to initialize output: %d\n", err);
 299                 return err;
 300         }
 301
 302         /*
 303          * Other outputs can be attached to either display controller. The RGB
 304          * outputs are an exception and work only with their parent display
 305          * controller.
 306          */
 307         output->encoder.possible_crtcs = drm_crtc_mask(&dc->base);
 308
 309         return 0;
 310 }
 311
 312 int tegra_dc_rgb_exit(struct tegra_dc *dc)
 313 {
 314         if (dc->rgb)
 315                 tegra_output_exit(dc->rgb);
 316
 317         return 0;
 318 }