1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2015 Free Electrons
4 * Copyright (C) 2015 NextThing Co
5 *
6 * Maxime Ripard <maxime.ripard@free-electrons.com>
7 */
8
9#include <linux/clk.h>
10
11#include <drm/drm_atomic_helper.h>
12#include <drm/drm_bridge.h>
13#include <drm/drm_of.h>
14#include <drm/drm_panel.h>
15#include <drm/drm_print.h>
16#include <drm/drm_probe_helper.h>
17#include <drm/drm_simple_kms_helper.h>
18
19#include "sun4i_crtc.h"
20#include "sun4i_tcon.h"
21#include "sun4i_rgb.h"
22
23struct sun4i_rgb {
24 struct drm_connector connector;
25 struct drm_encoder encoder;
26
27 struct sun4i_tcon *tcon;
28 struct drm_panel *panel;
29 struct drm_bridge *bridge;
30};
31
32static inline struct sun4i_rgb *
33drm_connector_to_sun4i_rgb(struct drm_connector *connector)
34{
35 return container_of(connector, struct sun4i_rgb,
36 connector);
37}
38
39static inline struct sun4i_rgb *
40drm_encoder_to_sun4i_rgb(struct drm_encoder *encoder)
41{
42 return container_of(encoder, struct sun4i_rgb,
43 encoder);
44}
45
46static int sun4i_rgb_get_modes(struct drm_connector *connector)
47{
48 struct sun4i_rgb *rgb =
49 drm_connector_to_sun4i_rgb(connector);
50
51 return drm_panel_get_modes(panel: rgb->panel, connector);
52}
53
54/*
55 * VESA DMT defines a tolerance of 0.5% on the pixel clock, while the
56 * CVT spec reuses that tolerance in its examples, so it looks to be a
57 * good default tolerance for the EDID-based modes. Define it to 5 per
58 * mille to avoid floating point operations.
59 */
60#define SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE 5
61
62static enum drm_mode_status sun4i_rgb_mode_valid(struct drm_encoder *crtc,
63 const struct drm_display_mode *mode)
64{
65 struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(encoder: crtc);
66 struct sun4i_tcon *tcon = rgb->tcon;
67 u32 hsync = mode->hsync_end - mode->hsync_start;
68 u32 vsync = mode->vsync_end - mode->vsync_start;
69 unsigned long long rate = mode->clock * 1000;
70 unsigned long long lowest, highest;
71 unsigned long long rounded_rate;
72
73 DRM_DEBUG_DRIVER("Validating modes...\n");
74
75 if (hsync < 1)
76 return MODE_HSYNC_NARROW;
77
78 if (hsync > 0x3ff)
79 return MODE_HSYNC_WIDE;
80
81 if ((mode->hdisplay < 1) || (mode->htotal < 1))
82 return MODE_H_ILLEGAL;
83
84 if ((mode->hdisplay > 0x7ff) || (mode->htotal > 0xfff))
85 return MODE_BAD_HVALUE;
86
87 DRM_DEBUG_DRIVER("Horizontal parameters OK\n");
88
89 if (vsync < 1)
90 return MODE_VSYNC_NARROW;
91
92 if (vsync > 0x3ff)
93 return MODE_VSYNC_WIDE;
94
95 if ((mode->vdisplay < 1) || (mode->vtotal < 1))
96 return MODE_V_ILLEGAL;
97
98 if ((mode->vdisplay > 0x7ff) || (mode->vtotal > 0xfff))
99 return MODE_BAD_VVALUE;
100
101 DRM_DEBUG_DRIVER("Vertical parameters OK\n");
102
103 /*
104 * TODO: We should use the struct display_timing if available
105 * and / or trying to stretch the timings within that
106 * tolerancy to take care of panels that we wouldn't be able
107 * to have a exact match for.
108 */
109 if (rgb->panel) {
110 DRM_DEBUG_DRIVER("RGB panel used, skipping clock rate checks");
111 goto out;
112 }
113
114 /*
115 * That shouldn't ever happen unless something is really wrong, but it
116 * doesn't harm to check.
117 */
118 if (!rgb->bridge)
119 goto out;
120
121 tcon->dclk_min_div = 6;
122 tcon->dclk_max_div = 127;
123 rounded_rate = clk_round_rate(clk: tcon->dclk, rate);
124
125 lowest = rate * (1000 - SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
126 do_div(lowest, 1000);
127 if (rounded_rate < lowest)
128 return MODE_CLOCK_LOW;
129
130 highest = rate * (1000 + SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
131 do_div(highest, 1000);
132 if (rounded_rate > highest)
133 return MODE_CLOCK_HIGH;
134
135out:
136 DRM_DEBUG_DRIVER("Clock rate OK\n");
137
138 return MODE_OK;
139}
140
141static const struct drm_connector_helper_funcs sun4i_rgb_con_helper_funcs = {
142 .get_modes = sun4i_rgb_get_modes,
143};
144
145static void
146sun4i_rgb_connector_destroy(struct drm_connector *connector)
147{
148 drm_connector_cleanup(connector);
149}
150
151static const struct drm_connector_funcs sun4i_rgb_con_funcs = {
152 .fill_modes = drm_helper_probe_single_connector_modes,
153 .destroy = sun4i_rgb_connector_destroy,
154 .reset = drm_atomic_helper_connector_reset,
155 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
156 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
157};
158
159static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder)
160{
161 struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(encoder);
162
163 DRM_DEBUG_DRIVER("Enabling RGB output\n");
164
165 if (rgb->panel) {
166 drm_panel_prepare(panel: rgb->panel);
167 drm_panel_enable(panel: rgb->panel);
168 }
169}
170
171static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
172{
173 struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(encoder);
174
175 DRM_DEBUG_DRIVER("Disabling RGB output\n");
176
177 if (rgb->panel) {
178 drm_panel_disable(panel: rgb->panel);
179 drm_panel_unprepare(panel: rgb->panel);
180 }
181}
182
183static const struct drm_encoder_helper_funcs sun4i_rgb_enc_helper_funcs = {
184 .disable = sun4i_rgb_encoder_disable,
185 .enable = sun4i_rgb_encoder_enable,
186 .mode_valid = sun4i_rgb_mode_valid,
187};
188
189int sun4i_rgb_init(struct drm_device *drm, struct sun4i_tcon *tcon)
190{
191 struct drm_encoder *encoder;
192 struct sun4i_rgb *rgb;
193 int ret;
194
195 rgb = devm_kzalloc(dev: drm->dev, size: sizeof(*rgb), GFP_KERNEL);
196 if (!rgb)
197 return -ENOMEM;
198 rgb->tcon = tcon;
199 encoder = &rgb->encoder;
200
201 ret = drm_of_find_panel_or_bridge(np: tcon->dev->of_node, port: 1, endpoint: 0,
202 panel: &rgb->panel, bridge: &rgb->bridge);
203 if (ret) {
204 dev_info(drm->dev, "No panel or bridge found... RGB output disabled\n");
205 return 0;
206 }
207
208 drm_encoder_helper_add(encoder: &rgb->encoder,
209 funcs: &sun4i_rgb_enc_helper_funcs);
210 ret = drm_simple_encoder_init(dev: drm, encoder: &rgb->encoder,
211 DRM_MODE_ENCODER_NONE);
212 if (ret) {
213 dev_err(drm->dev, "Couldn't initialise the rgb encoder\n");
214 goto err_out;
215 }
216
217 /* The RGB encoder can only work with the TCON channel 0 */
218 rgb->encoder.possible_crtcs = drm_crtc_mask(crtc: &tcon->crtc->crtc);
219
220 if (rgb->panel) {
221 drm_connector_helper_add(connector: &rgb->connector,
222 funcs: &sun4i_rgb_con_helper_funcs);
223 ret = drm_connector_init(dev: drm, connector: &rgb->connector,
224 funcs: &sun4i_rgb_con_funcs,
225 DRM_MODE_CONNECTOR_Unknown);
226 if (ret) {
227 dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
228 goto err_cleanup_connector;
229 }
230
231 drm_connector_attach_encoder(connector: &rgb->connector,
232 encoder: &rgb->encoder);
233 }
234
235 if (rgb->bridge) {
236 ret = drm_bridge_attach(encoder, bridge: rgb->bridge, NULL, flags: 0);
237 if (ret)
238 goto err_cleanup_connector;
239 }
240
241 return 0;
242
243err_cleanup_connector:
244 drm_encoder_cleanup(encoder: &rgb->encoder);
245err_out:
246 return ret;
247}
248EXPORT_SYMBOL(sun4i_rgb_init);
249

source code of linux/drivers/gpu/drm/sun4i/sun4i_rgb.c