1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2022 Marek Vasut <marex@denx.de>
4 */
5
6 #include <linux/clk.h>
7 #include <linux/media-bus-format.h>
8 #include <linux/mfd/syscon.h>
9 #include <linux/module.h>
10 #include <linux/of.h>
11 #include <linux/of_device.h>
12 #include <linux/of_graph.h>
13 #include <linux/platform_device.h>
14 #include <linux/regmap.h>
15
16 #include <drm/drm_atomic_helper.h>
17 #include <drm/drm_bridge.h>
18 #include <drm/drm_of.h>
19 #include <drm/drm_panel.h>
20
21 #define LDB_CTRL 0x5c
22 #define LDB_CTRL_CH0_ENABLE BIT(0)
23 #define LDB_CTRL_CH0_DI_SELECT BIT(1)
24 #define LDB_CTRL_CH1_ENABLE BIT(2)
25 #define LDB_CTRL_CH1_DI_SELECT BIT(3)
26 #define LDB_CTRL_SPLIT_MODE BIT(4)
27 #define LDB_CTRL_CH0_DATA_WIDTH BIT(5)
28 #define LDB_CTRL_CH0_BIT_MAPPING BIT(6)
29 #define LDB_CTRL_CH1_DATA_WIDTH BIT(7)
30 #define LDB_CTRL_CH1_BIT_MAPPING BIT(8)
31 #define LDB_CTRL_DI0_VSYNC_POLARITY BIT(9)
32 #define LDB_CTRL_DI1_VSYNC_POLARITY BIT(10)
33 #define LDB_CTRL_REG_CH0_FIFO_RESET BIT(11)
34 #define LDB_CTRL_REG_CH1_FIFO_RESET BIT(12)
35 #define LDB_CTRL_ASYNC_FIFO_ENABLE BIT(24)
36 #define LDB_CTRL_ASYNC_FIFO_THRESHOLD_MASK GENMASK(27, 25)
37
38 #define LVDS_CTRL 0x128
39 #define LVDS_CTRL_CH0_EN BIT(0)
40 #define LVDS_CTRL_CH1_EN BIT(1)
41 #define LVDS_CTRL_VBG_EN BIT(2)
42 #define LVDS_CTRL_HS_EN BIT(3)
43 #define LVDS_CTRL_PRE_EMPH_EN BIT(4)
44 #define LVDS_CTRL_PRE_EMPH_ADJ(n) (((n) & 0x7) << 5)
45 #define LVDS_CTRL_PRE_EMPH_ADJ_MASK GENMASK(7, 5)
46 #define LVDS_CTRL_CM_ADJ(n) (((n) & 0x7) << 8)
47 #define LVDS_CTRL_CM_ADJ_MASK GENMASK(10, 8)
48 #define LVDS_CTRL_CC_ADJ(n) (((n) & 0x7) << 11)
49 #define LVDS_CTRL_CC_ADJ_MASK GENMASK(13, 11)
50 #define LVDS_CTRL_SLEW_ADJ(n) (((n) & 0x7) << 14)
51 #define LVDS_CTRL_SLEW_ADJ_MASK GENMASK(16, 14)
52 #define LVDS_CTRL_VBG_ADJ(n) (((n) & 0x7) << 17)
53 #define LVDS_CTRL_VBG_ADJ_MASK GENMASK(19, 17)
54
55 struct fsl_ldb {
56 struct device *dev;
57 struct drm_bridge bridge;
58 struct drm_bridge *panel_bridge;
59 struct clk *clk;
60 struct regmap *regmap;
61 bool lvds_dual_link;
62 };
63
to_fsl_ldb(struct drm_bridge * bridge)64 static inline struct fsl_ldb *to_fsl_ldb(struct drm_bridge *bridge)
65 {
66 return container_of(bridge, struct fsl_ldb, bridge);
67 }
68
fsl_ldb_attach(struct drm_bridge * bridge,enum drm_bridge_attach_flags flags)69 static int fsl_ldb_attach(struct drm_bridge *bridge,
70 enum drm_bridge_attach_flags flags)
71 {
72 struct fsl_ldb *fsl_ldb = to_fsl_ldb(bridge);
73
74 return drm_bridge_attach(bridge->encoder, fsl_ldb->panel_bridge,
75 bridge, flags);
76 }
77
fsl_ldb_atomic_enable(struct drm_bridge * bridge,struct drm_bridge_state * old_bridge_state)78 static void fsl_ldb_atomic_enable(struct drm_bridge *bridge,
79 struct drm_bridge_state *old_bridge_state)
80 {
81 struct fsl_ldb *fsl_ldb = to_fsl_ldb(bridge);
82 struct drm_atomic_state *state = old_bridge_state->base.state;
83 const struct drm_bridge_state *bridge_state;
84 const struct drm_crtc_state *crtc_state;
85 const struct drm_display_mode *mode;
86 struct drm_connector *connector;
87 struct drm_crtc *crtc;
88 bool lvds_format_24bpp;
89 bool lvds_format_jeida;
90 u32 reg;
91
92 /* Get the LVDS format from the bridge state. */
93 bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
94
95 switch (bridge_state->output_bus_cfg.format) {
96 case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
97 lvds_format_24bpp = false;
98 lvds_format_jeida = true;
99 break;
100 case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
101 lvds_format_24bpp = true;
102 lvds_format_jeida = true;
103 break;
104 case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
105 lvds_format_24bpp = true;
106 lvds_format_jeida = false;
107 break;
108 default:
109 /*
110 * Some bridges still don't set the correct LVDS bus pixel
111 * format, use SPWG24 default format until those are fixed.
112 */
113 lvds_format_24bpp = true;
114 lvds_format_jeida = false;
115 dev_warn(fsl_ldb->dev,
116 "Unsupported LVDS bus format 0x%04x, please check output bridge driver. Falling back to SPWG24.\n",
117 bridge_state->output_bus_cfg.format);
118 break;
119 }
120
121 /*
122 * Retrieve the CRTC adjusted mode. This requires a little dance to go
123 * from the bridge to the encoder, to the connector and to the CRTC.
124 */
125 connector = drm_atomic_get_new_connector_for_encoder(state,
126 bridge->encoder);
127 crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
128 crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
129 mode = &crtc_state->adjusted_mode;
130
131 if (fsl_ldb->lvds_dual_link)
132 clk_set_rate(fsl_ldb->clk, mode->clock * 3500);
133 else
134 clk_set_rate(fsl_ldb->clk, mode->clock * 7000);
135 clk_prepare_enable(fsl_ldb->clk);
136
137 /* Program LDB_CTRL */
138 reg = LDB_CTRL_CH0_ENABLE;
139
140 if (fsl_ldb->lvds_dual_link)
141 reg |= LDB_CTRL_CH1_ENABLE | LDB_CTRL_SPLIT_MODE;
142
143 if (lvds_format_24bpp) {
144 reg |= LDB_CTRL_CH0_DATA_WIDTH;
145 if (fsl_ldb->lvds_dual_link)
146 reg |= LDB_CTRL_CH1_DATA_WIDTH;
147 }
148
149 if (lvds_format_jeida) {
150 reg |= LDB_CTRL_CH0_BIT_MAPPING;
151 if (fsl_ldb->lvds_dual_link)
152 reg |= LDB_CTRL_CH1_BIT_MAPPING;
153 }
154
155 if (mode->flags & DRM_MODE_FLAG_PVSYNC) {
156 reg |= LDB_CTRL_DI0_VSYNC_POLARITY;
157 if (fsl_ldb->lvds_dual_link)
158 reg |= LDB_CTRL_DI1_VSYNC_POLARITY;
159 }
160
161 regmap_write(fsl_ldb->regmap, LDB_CTRL, reg);
162
163 /* Program LVDS_CTRL */
164 reg = LVDS_CTRL_CC_ADJ(2) | LVDS_CTRL_PRE_EMPH_EN |
165 LVDS_CTRL_PRE_EMPH_ADJ(3) | LVDS_CTRL_VBG_EN;
166 regmap_write(fsl_ldb->regmap, LVDS_CTRL, reg);
167
168 /* Wait for VBG to stabilize. */
169 usleep_range(15, 20);
170
171 reg |= LVDS_CTRL_CH0_EN;
172 if (fsl_ldb->lvds_dual_link)
173 reg |= LVDS_CTRL_CH1_EN;
174
175 regmap_write(fsl_ldb->regmap, LVDS_CTRL, reg);
176 }
177
fsl_ldb_atomic_disable(struct drm_bridge * bridge,struct drm_bridge_state * old_bridge_state)178 static void fsl_ldb_atomic_disable(struct drm_bridge *bridge,
179 struct drm_bridge_state *old_bridge_state)
180 {
181 struct fsl_ldb *fsl_ldb = to_fsl_ldb(bridge);
182
183 /* Stop both channels. */
184 regmap_write(fsl_ldb->regmap, LVDS_CTRL, 0);
185 regmap_write(fsl_ldb->regmap, LDB_CTRL, 0);
186
187 clk_disable_unprepare(fsl_ldb->clk);
188 }
189
190 #define MAX_INPUT_SEL_FORMATS 1
191 static u32 *
fsl_ldb_atomic_get_input_bus_fmts(struct drm_bridge * bridge,struct drm_bridge_state * bridge_state,struct drm_crtc_state * crtc_state,struct drm_connector_state * conn_state,u32 output_fmt,unsigned int * num_input_fmts)192 fsl_ldb_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
193 struct drm_bridge_state *bridge_state,
194 struct drm_crtc_state *crtc_state,
195 struct drm_connector_state *conn_state,
196 u32 output_fmt,
197 unsigned int *num_input_fmts)
198 {
199 u32 *input_fmts;
200
201 *num_input_fmts = 0;
202
203 input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
204 GFP_KERNEL);
205 if (!input_fmts)
206 return NULL;
207
208 input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
209 *num_input_fmts = MAX_INPUT_SEL_FORMATS;
210
211 return input_fmts;
212 }
213
214 static enum drm_mode_status
fsl_ldb_mode_valid(struct drm_bridge * bridge,const struct drm_display_info * info,const struct drm_display_mode * mode)215 fsl_ldb_mode_valid(struct drm_bridge *bridge,
216 const struct drm_display_info *info,
217 const struct drm_display_mode *mode)
218 {
219 struct fsl_ldb *fsl_ldb = to_fsl_ldb(bridge);
220
221 if (mode->clock > (fsl_ldb->lvds_dual_link ? 160000 : 80000))
222 return MODE_CLOCK_HIGH;
223
224 return MODE_OK;
225 }
226
227 static const struct drm_bridge_funcs funcs = {
228 .attach = fsl_ldb_attach,
229 .atomic_enable = fsl_ldb_atomic_enable,
230 .atomic_disable = fsl_ldb_atomic_disable,
231 .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
232 .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
233 .atomic_get_input_bus_fmts = fsl_ldb_atomic_get_input_bus_fmts,
234 .atomic_reset = drm_atomic_helper_bridge_reset,
235 .mode_valid = fsl_ldb_mode_valid,
236 };
237
fsl_ldb_probe(struct platform_device * pdev)238 static int fsl_ldb_probe(struct platform_device *pdev)
239 {
240 struct device *dev = &pdev->dev;
241 struct device_node *panel_node;
242 struct device_node *port1, *port2;
243 struct drm_panel *panel;
244 struct fsl_ldb *fsl_ldb;
245 int dual_link;
246
247 fsl_ldb = devm_kzalloc(dev, sizeof(*fsl_ldb), GFP_KERNEL);
248 if (!fsl_ldb)
249 return -ENOMEM;
250
251 fsl_ldb->dev = &pdev->dev;
252 fsl_ldb->bridge.funcs = &funcs;
253 fsl_ldb->bridge.of_node = dev->of_node;
254
255 fsl_ldb->clk = devm_clk_get(dev, "ldb");
256 if (IS_ERR(fsl_ldb->clk))
257 return PTR_ERR(fsl_ldb->clk);
258
259 fsl_ldb->regmap = syscon_node_to_regmap(dev->of_node->parent);
260 if (IS_ERR(fsl_ldb->regmap))
261 return PTR_ERR(fsl_ldb->regmap);
262
263 /* Locate the panel DT node. */
264 panel_node = of_graph_get_remote_node(dev->of_node, 1, 0);
265 if (!panel_node)
266 return -ENXIO;
267
268 panel = of_drm_find_panel(panel_node);
269 of_node_put(panel_node);
270 if (IS_ERR(panel))
271 return PTR_ERR(panel);
272
273 fsl_ldb->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
274 if (IS_ERR(fsl_ldb->panel_bridge))
275 return PTR_ERR(fsl_ldb->panel_bridge);
276
277 /* Determine whether this is dual-link configuration */
278 port1 = of_graph_get_port_by_id(dev->of_node, 1);
279 port2 = of_graph_get_port_by_id(dev->of_node, 2);
280 dual_link = drm_of_lvds_get_dual_link_pixel_order(port1, port2);
281 of_node_put(port1);
282 of_node_put(port2);
283
284 if (dual_link == DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS) {
285 dev_err(dev, "LVDS channel pixel swap not supported.\n");
286 return -EINVAL;
287 }
288
289 if (dual_link == DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS)
290 fsl_ldb->lvds_dual_link = true;
291
292 platform_set_drvdata(pdev, fsl_ldb);
293
294 drm_bridge_add(&fsl_ldb->bridge);
295
296 return 0;
297 }
298
fsl_ldb_remove(struct platform_device * pdev)299 static int fsl_ldb_remove(struct platform_device *pdev)
300 {
301 struct fsl_ldb *fsl_ldb = platform_get_drvdata(pdev);
302
303 drm_bridge_remove(&fsl_ldb->bridge);
304
305 return 0;
306 }
307
308 static const struct of_device_id fsl_ldb_match[] = {
309 { .compatible = "fsl,imx8mp-ldb", },
310 { /* sentinel */ },
311 };
312 MODULE_DEVICE_TABLE(of, fsl_ldb_match);
313
314 static struct platform_driver fsl_ldb_driver = {
315 .probe = fsl_ldb_probe,
316 .remove = fsl_ldb_remove,
317 .driver = {
318 .name = "fsl-ldb",
319 .of_match_table = fsl_ldb_match,
320 },
321 };
322 module_platform_driver(fsl_ldb_driver);
323
324 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
325 MODULE_DESCRIPTION("Freescale i.MX8MP LDB");
326 MODULE_LICENSE("GPL");
327
