xref: /openbmc/linux/drivers/gpu/drm/sun4i/sun4i_lvds.c (revision a48c7709)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017 Free Electrons
4  * Maxime Ripard <maxime.ripard@free-electrons.com>
5  */
6 
7 #include <linux/clk.h>
8 
9 #include <drm/drmP.h>
10 #include <drm/drm_atomic_helper.h>
11 #include <drm/drm_crtc_helper.h>
12 #include <drm/drm_of.h>
13 #include <drm/drm_panel.h>
14 
15 #include "sun4i_crtc.h"
16 #include "sun4i_tcon.h"
17 #include "sun4i_lvds.h"
18 
19 struct sun4i_lvds {
20 	struct drm_connector	connector;
21 	struct drm_encoder	encoder;
22 
23 	struct sun4i_tcon	*tcon;
24 };
25 
26 static inline struct sun4i_lvds *
27 drm_connector_to_sun4i_lvds(struct drm_connector *connector)
28 {
29 	return container_of(connector, struct sun4i_lvds,
30 			    connector);
31 }
32 
33 static inline struct sun4i_lvds *
34 drm_encoder_to_sun4i_lvds(struct drm_encoder *encoder)
35 {
36 	return container_of(encoder, struct sun4i_lvds,
37 			    encoder);
38 }
39 
40 static int sun4i_lvds_get_modes(struct drm_connector *connector)
41 {
42 	struct sun4i_lvds *lvds =
43 		drm_connector_to_sun4i_lvds(connector);
44 	struct sun4i_tcon *tcon = lvds->tcon;
45 
46 	return drm_panel_get_modes(tcon->panel);
47 }
48 
49 static struct drm_connector_helper_funcs sun4i_lvds_con_helper_funcs = {
50 	.get_modes	= sun4i_lvds_get_modes,
51 };
52 
53 static void
54 sun4i_lvds_connector_destroy(struct drm_connector *connector)
55 {
56 	struct sun4i_lvds *lvds = drm_connector_to_sun4i_lvds(connector);
57 	struct sun4i_tcon *tcon = lvds->tcon;
58 
59 	drm_panel_detach(tcon->panel);
60 	drm_connector_cleanup(connector);
61 }
62 
63 static const struct drm_connector_funcs sun4i_lvds_con_funcs = {
64 	.fill_modes		= drm_helper_probe_single_connector_modes,
65 	.destroy		= sun4i_lvds_connector_destroy,
66 	.reset			= drm_atomic_helper_connector_reset,
67 	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
68 	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
69 };
70 
71 static void sun4i_lvds_encoder_enable(struct drm_encoder *encoder)
72 {
73 	struct sun4i_lvds *lvds = drm_encoder_to_sun4i_lvds(encoder);
74 	struct sun4i_tcon *tcon = lvds->tcon;
75 
76 	DRM_DEBUG_DRIVER("Enabling LVDS output\n");
77 
78 	if (!IS_ERR(tcon->panel)) {
79 		drm_panel_prepare(tcon->panel);
80 		drm_panel_enable(tcon->panel);
81 	}
82 }
83 
84 static void sun4i_lvds_encoder_disable(struct drm_encoder *encoder)
85 {
86 	struct sun4i_lvds *lvds = drm_encoder_to_sun4i_lvds(encoder);
87 	struct sun4i_tcon *tcon = lvds->tcon;
88 
89 	DRM_DEBUG_DRIVER("Disabling LVDS output\n");
90 
91 	if (!IS_ERR(tcon->panel)) {
92 		drm_panel_disable(tcon->panel);
93 		drm_panel_unprepare(tcon->panel);
94 	}
95 }
96 
97 static enum drm_mode_status sun4i_lvds_encoder_mode_valid(struct drm_encoder *crtc,
98 							  const struct drm_display_mode *mode)
99 {
100 	struct sun4i_lvds *lvds = drm_encoder_to_sun4i_lvds(crtc);
101 	struct sun4i_tcon *tcon = lvds->tcon;
102 	u32 hsync = mode->hsync_end - mode->hsync_start;
103 	u32 vsync = mode->vsync_end - mode->vsync_start;
104 	unsigned long rate = mode->clock * 1000;
105 	long rounded_rate;
106 
107 	DRM_DEBUG_DRIVER("Validating modes...\n");
108 
109 	if (hsync < 1)
110 		return MODE_HSYNC_NARROW;
111 
112 	if (hsync > 0x3ff)
113 		return MODE_HSYNC_WIDE;
114 
115 	if ((mode->hdisplay < 1) || (mode->htotal < 1))
116 		return MODE_H_ILLEGAL;
117 
118 	if ((mode->hdisplay > 0x7ff) || (mode->htotal > 0xfff))
119 		return MODE_BAD_HVALUE;
120 
121 	DRM_DEBUG_DRIVER("Horizontal parameters OK\n");
122 
123 	if (vsync < 1)
124 		return MODE_VSYNC_NARROW;
125 
126 	if (vsync > 0x3ff)
127 		return MODE_VSYNC_WIDE;
128 
129 	if ((mode->vdisplay < 1) || (mode->vtotal < 1))
130 		return MODE_V_ILLEGAL;
131 
132 	if ((mode->vdisplay > 0x7ff) || (mode->vtotal > 0xfff))
133 		return MODE_BAD_VVALUE;
134 
135 	DRM_DEBUG_DRIVER("Vertical parameters OK\n");
136 
137 	tcon->dclk_min_div = 7;
138 	tcon->dclk_max_div = 7;
139 	rounded_rate = clk_round_rate(tcon->dclk, rate);
140 	if (rounded_rate < rate)
141 		return MODE_CLOCK_LOW;
142 
143 	if (rounded_rate > rate)
144 		return MODE_CLOCK_HIGH;
145 
146 	DRM_DEBUG_DRIVER("Clock rate OK\n");
147 
148 	return MODE_OK;
149 }
150 
151 static const struct drm_encoder_helper_funcs sun4i_lvds_enc_helper_funcs = {
152 	.disable	= sun4i_lvds_encoder_disable,
153 	.enable		= sun4i_lvds_encoder_enable,
154 	.mode_valid	= sun4i_lvds_encoder_mode_valid,
155 };
156 
157 static const struct drm_encoder_funcs sun4i_lvds_enc_funcs = {
158 	.destroy	= drm_encoder_cleanup,
159 };
160 
161 int sun4i_lvds_init(struct drm_device *drm, struct sun4i_tcon *tcon)
162 {
163 	struct drm_encoder *encoder;
164 	struct drm_bridge *bridge;
165 	struct sun4i_lvds *lvds;
166 	int ret;
167 
168 	lvds = devm_kzalloc(drm->dev, sizeof(*lvds), GFP_KERNEL);
169 	if (!lvds)
170 		return -ENOMEM;
171 	lvds->tcon = tcon;
172 	encoder = &lvds->encoder;
173 
174 	ret = drm_of_find_panel_or_bridge(tcon->dev->of_node, 1, 0,
175 					  &tcon->panel, &bridge);
176 	if (ret) {
177 		dev_info(drm->dev, "No panel or bridge found... LVDS output disabled\n");
178 		return 0;
179 	}
180 
181 	drm_encoder_helper_add(&lvds->encoder,
182 			       &sun4i_lvds_enc_helper_funcs);
183 	ret = drm_encoder_init(drm,
184 			       &lvds->encoder,
185 			       &sun4i_lvds_enc_funcs,
186 			       DRM_MODE_ENCODER_LVDS,
187 			       NULL);
188 	if (ret) {
189 		dev_err(drm->dev, "Couldn't initialise the lvds encoder\n");
190 		goto err_out;
191 	}
192 
193 	/* The LVDS encoder can only work with the TCON channel 0 */
194 	lvds->encoder.possible_crtcs = BIT(drm_crtc_index(&tcon->crtc->crtc));
195 
196 	if (tcon->panel) {
197 		drm_connector_helper_add(&lvds->connector,
198 					 &sun4i_lvds_con_helper_funcs);
199 		ret = drm_connector_init(drm, &lvds->connector,
200 					 &sun4i_lvds_con_funcs,
201 					 DRM_MODE_CONNECTOR_LVDS);
202 		if (ret) {
203 			dev_err(drm->dev, "Couldn't initialise the lvds connector\n");
204 			goto err_cleanup_connector;
205 		}
206 
207 		drm_mode_connector_attach_encoder(&lvds->connector,
208 						  &lvds->encoder);
209 
210 		ret = drm_panel_attach(tcon->panel, &lvds->connector);
211 		if (ret) {
212 			dev_err(drm->dev, "Couldn't attach our panel\n");
213 			goto err_cleanup_connector;
214 		}
215 	}
216 
217 	if (bridge) {
218 		ret = drm_bridge_attach(encoder, bridge, NULL);
219 		if (ret) {
220 			dev_err(drm->dev, "Couldn't attach our bridge\n");
221 			goto err_cleanup_connector;
222 		}
223 	}
224 
225 	return 0;
226 
227 err_cleanup_connector:
228 	drm_encoder_cleanup(&lvds->encoder);
229 err_out:
230 	return ret;
231 }
232 EXPORT_SYMBOL(sun4i_lvds_init);
233