drivers/gpu/drm/tegra/rgb.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2012 Avionic Design GmbH
   4  * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
   5  */
   6
   7 #include <linux/clk.h>
   8
   9 #include <drm/drm_atomic_helper.h>
  10 #include <drm/drm_panel.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
  19         struct clk *clk_parent;
  20         struct clk *clk;
  21 };
  22
  23 static inline struct tegra_rgb *to_rgb(struct tegra_output *output)
  24 {
  25         return container_of(output, struct tegra_rgb, output);
  26 }
  27
  28 struct reg_entry {
  29         unsigned long offset;
  30         unsigned long value;
  31 };
  32
  33 static const struct reg_entry rgb_enable[] = {
  34         { DC_COM_PIN_OUTPUT_ENABLE(0),   0x00000000 },
  35         { DC_COM_PIN_OUTPUT_ENABLE(1),   0x00000000 },
  36         { DC_COM_PIN_OUTPUT_ENABLE(2),   0x00000000 },
  37         { DC_COM_PIN_OUTPUT_ENABLE(3),   0x00000000 },
  38         { DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
  39         { DC_COM_PIN_OUTPUT_POLARITY(1), 0x01000000 },
  40         { DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
  41         { DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
  42         { DC_COM_PIN_OUTPUT_DATA(0),     0x00000000 },
  43         { DC_COM_PIN_OUTPUT_DATA(1),     0x00000000 },
  44         { DC_COM_PIN_OUTPUT_DATA(2),     0x00000000 },
  45         { DC_COM_PIN_OUTPUT_DATA(3),     0x00000000 },
  46         { DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
  47         { DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
  48         { DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
  49         { DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
  50         { DC_COM_PIN_OUTPUT_SELECT(4),   0x00210222 },
  51         { DC_COM_PIN_OUTPUT_SELECT(5),   0x00002200 },
  52         { DC_COM_PIN_OUTPUT_SELECT(6),   0x00020000 },
  53 };
  54
  55 static const struct reg_entry rgb_disable[] = {
  56         { DC_COM_PIN_OUTPUT_SELECT(6),   0x00000000 },
  57         { DC_COM_PIN_OUTPUT_SELECT(5),   0x00000000 },
  58         { DC_COM_PIN_OUTPUT_SELECT(4),   0x00000000 },
  59         { DC_COM_PIN_OUTPUT_SELECT(3),   0x00000000 },
  60         { DC_COM_PIN_OUTPUT_SELECT(2),   0x00000000 },
  61         { DC_COM_PIN_OUTPUT_SELECT(1),   0x00000000 },
  62         { DC_COM_PIN_OUTPUT_SELECT(0),   0x00000000 },
  63         { DC_COM_PIN_OUTPUT_DATA(3),     0xaaaaaaaa },
  64         { DC_COM_PIN_OUTPUT_DATA(2),     0xaaaaaaaa },
  65         { DC_COM_PIN_OUTPUT_DATA(1),     0xaaaaaaaa },
  66         { DC_COM_PIN_OUTPUT_DATA(0),     0xaaaaaaaa },
  67         { DC_COM_PIN_OUTPUT_POLARITY(3), 0x00000000 },
  68         { DC_COM_PIN_OUTPUT_POLARITY(2), 0x00000000 },
  69         { DC_COM_PIN_OUTPUT_POLARITY(1), 0x00000000 },
  70         { DC_COM_PIN_OUTPUT_POLARITY(0), 0x00000000 },
  71         { DC_COM_PIN_OUTPUT_ENABLE(3),   0x55555555 },
  72         { DC_COM_PIN_OUTPUT_ENABLE(2),   0x55555555 },
  73         { DC_COM_PIN_OUTPUT_ENABLE(1),   0x55150005 },
  74         { DC_COM_PIN_OUTPUT_ENABLE(0),   0x55555555 },
  75 };
  76
  77 static void tegra_dc_write_regs(struct tegra_dc *dc,
  78                                 const struct reg_entry *table,
  79                                 unsigned int num)
  80 {
  81         unsigned int i;
  82
  83         for (i = 0; i < num; i++)
  84                 tegra_dc_writel(dc, table[i].value, table[i].offset);
  85 }
  86
  87 static const struct drm_connector_funcs tegra_rgb_connector_funcs = {
  88         .reset = drm_atomic_helper_connector_reset,
  89         .detect = tegra_output_connector_detect,
  90         .fill_modes = drm_helper_probe_single_connector_modes,
  91         .destroy = tegra_output_connector_destroy,
  92         .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
  93         .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
  94 };
  95
  96 static enum drm_mode_status
  97 tegra_rgb_connector_mode_valid(struct drm_connector *connector,
  98                                struct drm_display_mode *mode)
  99 {
 100         /*
 101          * FIXME: For now, always assume that the mode is okay. There are
 102          * unresolved issues with clk_round_rate(), which doesn't always
 103          * reliably report whether a frequency can be set or not.
 104          */
 105         return MODE_OK;
 106 }
 107
 108 static const struct drm_connector_helper_funcs tegra_rgb_connector_helper_funcs = {
 109         .get_modes = tegra_output_connector_get_modes,
 110         .mode_valid = tegra_rgb_connector_mode_valid,
 111 };
 112
 113 static const struct drm_encoder_funcs tegra_rgb_encoder_funcs = {
 114         .destroy = tegra_output_encoder_destroy,
 115 };
 116
 117 static void tegra_rgb_encoder_disable(struct drm_encoder *encoder)
 118 {
 119         struct tegra_output *output = encoder_to_output(encoder);
 120         struct tegra_rgb *rgb = to_rgb(output);
 121
 122         if (output->panel)
 123                 drm_panel_disable(output->panel);
 124
 125         tegra_dc_write_regs(rgb->dc, rgb_disable, ARRAY_SIZE(rgb_disable));
 126         tegra_dc_commit(rgb->dc);
 127
 128         if (output->panel)
 129                 drm_panel_unprepare(output->panel);
 130 }
 131
 132 static void tegra_rgb_encoder_enable(struct drm_encoder *encoder)
 133 {
 134         struct tegra_output *output = encoder_to_output(encoder);
 135         struct tegra_rgb *rgb = to_rgb(output);
 136         u32 value;
 137
 138         if (output->panel)
 139                 drm_panel_prepare(output->panel);
 140
 141         tegra_dc_write_regs(rgb->dc, rgb_enable, ARRAY_SIZE(rgb_enable));
 142
 143         value = DE_SELECT_ACTIVE | DE_CONTROL_NORMAL;
 144         tegra_dc_writel(rgb->dc, value, DC_DISP_DATA_ENABLE_OPTIONS);
 145
 146         /* XXX: parameterize? */
 147         value = tegra_dc_readl(rgb->dc, DC_COM_PIN_OUTPUT_POLARITY(1));
 148         value &= ~LVS_OUTPUT_POLARITY_LOW;
 149         value &= ~LHS_OUTPUT_POLARITY_LOW;
 150         tegra_dc_writel(rgb->dc, value, DC_COM_PIN_OUTPUT_POLARITY(1));
 151
 152         /* XXX: parameterize? */
 153         value = DISP_DATA_FORMAT_DF1P1C | DISP_ALIGNMENT_MSB |
 154                 DISP_ORDER_RED_BLUE;
 155         tegra_dc_writel(rgb->dc, value, DC_DISP_DISP_INTERFACE_CONTROL);
 156
 157         /* XXX: parameterize? */
 158         value = SC0_H_QUALIFIER_NONE | SC1_H_QUALIFIER_NONE;
 159         tegra_dc_writel(rgb->dc, value, DC_DISP_SHIFT_CLOCK_OPTIONS);
 160
 161         tegra_dc_commit(rgb->dc);
 162
 163         if (output->panel)
 164                 drm_panel_enable(output->panel);
 165 }
 166
 167 static int
 168 tegra_rgb_encoder_atomic_check(struct drm_encoder *encoder,
 169                                struct drm_crtc_state *crtc_state,
 170                                struct drm_connector_state *conn_state)
 171 {
 172         struct tegra_output *output = encoder_to_output(encoder);
 173         struct tegra_dc *dc = to_tegra_dc(conn_state->crtc);
 174         unsigned long pclk = crtc_state->mode.clock * 1000;
 175         struct tegra_rgb *rgb = to_rgb(output);
 176         unsigned int div;
 177         int err;
 178
 179         /*
 180          * We may not want to change the frequency of the parent clock, since
 181          * it may be a parent for other peripherals. This is due to the fact
 182          * that on Tegra20 there's only a single clock dedicated to display
 183          * (pll_d_out0), whereas later generations have a second one that can
 184          * be used to independently drive a second output (pll_d2_out0).
 185          *
 186          * As a way to support multiple outputs on Tegra20 as well, pll_p is
 187          * typically used as the parent clock for the display controllers.
 188          * But this comes at a cost: pll_p is the parent of several other
 189          * peripherals, so its frequency shouldn't change out of the blue.
 190          *
 191          * The best we can do at this point is to use the shift clock divider
 192          * and hope that the desired frequency can be matched (or at least
 193          * matched sufficiently close that the panel will still work).
 194          */
 195         div = ((clk_get_rate(rgb->clk) * 2) / pclk) - 2;
 196         pclk = 0;
 197
 198         err = tegra_dc_state_setup_clock(dc, crtc_state, rgb->clk_parent,
 199                                          pclk, div);
 200         if (err < 0) {
 201                 dev_err(output->dev, "failed to setup CRTC state: %d\n", err);
 202                 return err;
 203         }
 204
 205         return err;
 206 }
 207
 208 static const struct drm_encoder_helper_funcs tegra_rgb_encoder_helper_funcs = {
 209         .disable = tegra_rgb_encoder_disable,
 210         .enable = tegra_rgb_encoder_enable,
 211         .atomic_check = tegra_rgb_encoder_atomic_check,
 212 };
 213
 214 int tegra_dc_rgb_probe(struct tegra_dc *dc)
 215 {
 216         struct device_node *np;
 217         struct tegra_rgb *rgb;
 218         int err;
 219
 220         np = of_get_child_by_name(dc->dev->of_node, "rgb");
 221         if (!np || !of_device_is_available(np))
 222                 return -ENODEV;
 223
 224         rgb = devm_kzalloc(dc->dev, sizeof(*rgb), GFP_KERNEL);
 225         if (!rgb)
 226                 return -ENOMEM;
 227
 228         rgb->output.dev = dc->dev;
 229         rgb->output.of_node = np;
 230         rgb->dc = dc;
 231
 232         err = tegra_output_probe(&rgb->output);
 233         if (err < 0)
 234                 return err;
 235
 236         rgb->clk = devm_clk_get(dc->dev, NULL);
 237         if (IS_ERR(rgb->clk)) {
 238                 dev_err(dc->dev, "failed to get clock\n");
 239                 return PTR_ERR(rgb->clk);
 240         }
 241
 242         rgb->clk_parent = devm_clk_get(dc->dev, "parent");
 243         if (IS_ERR(rgb->clk_parent)) {
 244                 dev_err(dc->dev, "failed to get parent clock\n");
 245                 return PTR_ERR(rgb->clk_parent);
 246         }
 247
 248         err = clk_set_parent(rgb->clk, rgb->clk_parent);
 249         if (err < 0) {
 250                 dev_err(dc->dev, "failed to set parent clock: %d\n", err);
 251                 return err;
 252         }
 253
 254         dc->rgb = &rgb->output;
 255
 256         return 0;
 257 }
 258
 259 int tegra_dc_rgb_remove(struct tegra_dc *dc)
 260 {
 261         if (!dc->rgb)
 262                 return 0;
 263
 264         tegra_output_remove(dc->rgb);
 265         dc->rgb = NULL;
 266
 267         return 0;
 268 }
 269
 270 int tegra_dc_rgb_init(struct drm_device *drm, struct tegra_dc *dc)
 271 {
 272         struct tegra_output *output = dc->rgb;
 273         int err;
 274
 275         if (!dc->rgb)
 276                 return -ENODEV;
 277
 278         drm_connector_init(drm, &output->connector, &tegra_rgb_connector_funcs,
 279                            DRM_MODE_CONNECTOR_LVDS);
 280         drm_connector_helper_add(&output->connector,
 281                                  &tegra_rgb_connector_helper_funcs);
 282         output->connector.dpms = DRM_MODE_DPMS_OFF;
 283
 284         drm_encoder_init(drm, &output->encoder, &tegra_rgb_encoder_funcs,
 285                          DRM_MODE_ENCODER_LVDS, NULL);
 286         drm_encoder_helper_add(&output->encoder,
 287                                &tegra_rgb_encoder_helper_funcs);
 288
 289         drm_connector_attach_encoder(&output->connector,
 290                                           &output->encoder);
 291         drm_connector_register(&output->connector);
 292
 293         err = tegra_output_init(drm, output);
 294         if (err < 0) {
 295                 dev_err(output->dev, "failed to initialize output: %d\n", err);
 296                 return err;
 297         }
 298
 299         /*
 300          * Other outputs can be attached to either display controller. The RGB
 301          * outputs are an exception and work only with their parent display
 302          * controller.
 303          */
 304         output->encoder.possible_crtcs = drm_crtc_mask(&dc->base);
 305
 306         return 0;
 307 }
 308
 309 int tegra_dc_rgb_exit(struct tegra_dc *dc)
 310 {
 311         if (dc->rgb)
 312                 tegra_output_exit(dc->rgb);
 313
 314         return 0;
 315 }