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_of.h>
 13#include <drm/drm_panel.h>
 14#include <drm/drm_print.h>
 15#include <drm/drm_probe_helper.h>
 16
 17#include "sun4i_crtc.h"
 18#include "sun4i_tcon.h"
 19#include "sun4i_rgb.h"
 20
 21struct sun4i_rgb {
 22	struct drm_connector	connector;
 23	struct drm_encoder	encoder;
 24
 25	struct sun4i_tcon	*tcon;
 26	struct drm_panel	*panel;
 27	struct drm_bridge	*bridge;
 28};
 29
 30static inline struct sun4i_rgb *
 31drm_connector_to_sun4i_rgb(struct drm_connector *connector)
 32{
 33	return container_of(connector, struct sun4i_rgb,
 34			    connector);
 35}
 36
 37static inline struct sun4i_rgb *
 38drm_encoder_to_sun4i_rgb(struct drm_encoder *encoder)
 39{
 40	return container_of(encoder, struct sun4i_rgb,
 41			    encoder);
 42}
 43
 44static int sun4i_rgb_get_modes(struct drm_connector *connector)
 45{
 46	struct sun4i_rgb *rgb =
 47		drm_connector_to_sun4i_rgb(connector);
 48
 49	return drm_panel_get_modes(rgb->panel);
 50}
 51
 52/*
 53 * VESA DMT defines a tolerance of 0.5% on the pixel clock, while the
 54 * CVT spec reuses that tolerance in its examples, so it looks to be a
 55 * good default tolerance for the EDID-based modes. Define it to 5 per
 56 * mille to avoid floating point operations.
 57 */
 58#define SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE	5
 59
 60static enum drm_mode_status sun4i_rgb_mode_valid(struct drm_encoder *crtc,
 61						 const struct drm_display_mode *mode)
 62{
 63	struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(crtc);
 64	struct sun4i_tcon *tcon = rgb->tcon;
 65	u32 hsync = mode->hsync_end - mode->hsync_start;
 66	u32 vsync = mode->vsync_end - mode->vsync_start;
 67	unsigned long long rate = mode->clock * 1000;
 68	unsigned long long lowest, highest;
 69	unsigned long long rounded_rate;
 70
 71	DRM_DEBUG_DRIVER("Validating modes...\n");
 72
 73	if (hsync < 1)
 74		return MODE_HSYNC_NARROW;
 75
 76	if (hsync > 0x3ff)
 77		return MODE_HSYNC_WIDE;
 78
 79	if ((mode->hdisplay < 1) || (mode->htotal < 1))
 80		return MODE_H_ILLEGAL;
 81
 82	if ((mode->hdisplay > 0x7ff) || (mode->htotal > 0xfff))
 83		return MODE_BAD_HVALUE;
 84
 85	DRM_DEBUG_DRIVER("Horizontal parameters OK\n");
 86
 87	if (vsync < 1)
 88		return MODE_VSYNC_NARROW;
 89
 90	if (vsync > 0x3ff)
 91		return MODE_VSYNC_WIDE;
 92
 93	if ((mode->vdisplay < 1) || (mode->vtotal < 1))
 94		return MODE_V_ILLEGAL;
 95
 96	if ((mode->vdisplay > 0x7ff) || (mode->vtotal > 0xfff))
 97		return MODE_BAD_VVALUE;
 98
 99	DRM_DEBUG_DRIVER("Vertical parameters OK\n");
100
101	/*
102	 * TODO: We should use the struct display_timing if available
103	 * and / or trying to stretch the timings within that
104	 * tolerancy to take care of panels that we wouldn't be able
105	 * to have a exact match for.
106	 */
107	if (rgb->panel) {
108		DRM_DEBUG_DRIVER("RGB panel used, skipping clock rate checks");
109		goto out;
110	}
111
112	/*
113	 * That shouldn't ever happen unless something is really wrong, but it
114	 * doesn't harm to check.
115	 */
116	if (!rgb->bridge)
117		goto out;
118
119	tcon->dclk_min_div = 6;
120	tcon->dclk_max_div = 127;
121	rounded_rate = clk_round_rate(tcon->dclk, rate);
122
123	lowest = rate * (1000 - SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
124	do_div(lowest, 1000);
125	if (rounded_rate < lowest)
126		return MODE_CLOCK_LOW;
127
128	highest = rate * (1000 + SUN4I_RGB_DOTCLOCK_TOLERANCE_PER_MILLE);
129	do_div(highest, 1000);
130	if (rounded_rate > highest)
131		return MODE_CLOCK_HIGH;
132
133out:
134	DRM_DEBUG_DRIVER("Clock rate OK\n");
135
136	return MODE_OK;
137}
138
139static struct drm_connector_helper_funcs sun4i_rgb_con_helper_funcs = {
140	.get_modes	= sun4i_rgb_get_modes,
141};
142
143static void
144sun4i_rgb_connector_destroy(struct drm_connector *connector)
145{
146	struct sun4i_rgb *rgb = drm_connector_to_sun4i_rgb(connector);
147
148	drm_panel_detach(rgb->panel);
149	drm_connector_cleanup(connector);
150}
151
152static const struct drm_connector_funcs sun4i_rgb_con_funcs = {
153	.fill_modes		= drm_helper_probe_single_connector_modes,
154	.destroy		= sun4i_rgb_connector_destroy,
155	.reset			= drm_atomic_helper_connector_reset,
156	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
157	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
158};
159
160static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder)
161{
162	struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(encoder);
163
164	DRM_DEBUG_DRIVER("Enabling RGB output\n");
165
166	if (rgb->panel) {
167		drm_panel_prepare(rgb->panel);
168		drm_panel_enable(rgb->panel);
169	}
170}
171
172static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
173{
174	struct sun4i_rgb *rgb = drm_encoder_to_sun4i_rgb(encoder);
175
176	DRM_DEBUG_DRIVER("Disabling RGB output\n");
177
178	if (rgb->panel) {
179		drm_panel_disable(rgb->panel);
180		drm_panel_unprepare(rgb->panel);
181	}
182}
183
184static struct drm_encoder_helper_funcs sun4i_rgb_enc_helper_funcs = {
185	.disable	= sun4i_rgb_encoder_disable,
186	.enable		= sun4i_rgb_encoder_enable,
187	.mode_valid	= sun4i_rgb_mode_valid,
188};
189
190static void sun4i_rgb_enc_destroy(struct drm_encoder *encoder)
191{
192	drm_encoder_cleanup(encoder);
193}
194
195static struct drm_encoder_funcs sun4i_rgb_enc_funcs = {
196	.destroy	= sun4i_rgb_enc_destroy,
197};
198
199int sun4i_rgb_init(struct drm_device *drm, struct sun4i_tcon *tcon)
200{
201	struct drm_encoder *encoder;
202	struct sun4i_rgb *rgb;
203	int ret;
204
205	rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
206	if (!rgb)
207		return -ENOMEM;
208	rgb->tcon = tcon;
209	encoder = &rgb->encoder;
210
211	ret = drm_of_find_panel_or_bridge(tcon->dev->of_node, 1, 0,
212					  &rgb->panel, &rgb->bridge);
213	if (ret) {
214		dev_info(drm->dev, "No panel or bridge found... RGB output disabled\n");
215		return 0;
216	}
217
218	drm_encoder_helper_add(&rgb->encoder,
219			       &sun4i_rgb_enc_helper_funcs);
220	ret = drm_encoder_init(drm,
221			       &rgb->encoder,
222			       &sun4i_rgb_enc_funcs,
223			       DRM_MODE_ENCODER_NONE,
224			       NULL);
225	if (ret) {
226		dev_err(drm->dev, "Couldn't initialise the rgb encoder\n");
227		goto err_out;
228	}
229
230	/* The RGB encoder can only work with the TCON channel 0 */
231	rgb->encoder.possible_crtcs = drm_crtc_mask(&tcon->crtc->crtc);
232
233	if (rgb->panel) {
234		drm_connector_helper_add(&rgb->connector,
235					 &sun4i_rgb_con_helper_funcs);
236		ret = drm_connector_init(drm, &rgb->connector,
237					 &sun4i_rgb_con_funcs,
238					 DRM_MODE_CONNECTOR_Unknown);
239		if (ret) {
240			dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
241			goto err_cleanup_connector;
242		}
243
244		drm_connector_attach_encoder(&rgb->connector,
245						  &rgb->encoder);
246
247		ret = drm_panel_attach(rgb->panel, &rgb->connector);
248		if (ret) {
249			dev_err(drm->dev, "Couldn't attach our panel\n");
250			goto err_cleanup_connector;
251		}
252	}
253
254	if (rgb->bridge) {
255		ret = drm_bridge_attach(encoder, rgb->bridge, NULL);
256		if (ret) {
257			dev_err(drm->dev, "Couldn't attach our bridge\n");
258			goto err_cleanup_connector;
259		}
260	}
261
262	return 0;
263
264err_cleanup_connector:
265	drm_encoder_cleanup(&rgb->encoder);
266err_out:
267	return ret;
268}
269EXPORT_SYMBOL(sun4i_rgb_init);