1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Panel driver for the ARM Versatile family reference designs from
4 * ARM Limited.
5 *
6 * Author:
7 * Linus Walleij <linus.wallei@linaro.org>
8 *
9 * On the Versatile AB, these panels come mounted on daughterboards
10 * named "IB1" or "IB2" (Interface Board 1 & 2 respectively.) They
11 * are documented in ARM DUI 0225D Appendix C and D. These daughter
12 * boards support TFT display panels.
13 *
14 * - The IB1 is a passive board where the display connector defines a
15 * few wires for encoding the display type for autodetection,
16 * suitable display settings can then be looked up from this setting.
17 * The magic bits can be read out from the system controller.
18 *
19 * - The IB2 is a more complex board intended for GSM phone development
20 * with some logic and a control register, which needs to be accessed
21 * and the board display needs to be turned on explicitly.
22 *
23 * On the Versatile PB, a special CLCD adaptor board is available
24 * supporting the same displays as the Versatile AB, plus one more
25 * Epson QCIF display.
26 *
27 */
28
29 #include <linux/bitops.h>
30 #include <linux/init.h>
31 #include <linux/kernel.h>
32 #include <linux/mfd/syscon.h>
33 #include <linux/module.h>
34 #include <linux/platform_device.h>
35 #include <linux/regmap.h>
36
37 #include <video/of_videomode.h>
38 #include <video/videomode.h>
39
40 #include <drm/drm_modes.h>
41 #include <drm/drm_panel.h>
42
43 /*
44 * This configuration register in the Versatile and RealView
45 * family is uniformly present but appears more and more
46 * unutilized starting with the RealView series.
47 */
48 #define SYS_CLCD 0x50
49
50 /* The Versatile can detect the connected panel type */
51 #define SYS_CLCD_CLCDID_MASK (BIT(8)|BIT(9)|BIT(10)|BIT(11)|BIT(12))
52 #define SYS_CLCD_ID_SANYO_3_8 (0x00 << 8)
53 #define SYS_CLCD_ID_SHARP_8_4 (0x01 << 8)
54 #define SYS_CLCD_ID_EPSON_2_2 (0x02 << 8)
55 #define SYS_CLCD_ID_SANYO_2_5 (0x07 << 8)
56 #define SYS_CLCD_ID_VGA (0x1f << 8)
57
58 /* IB2 control register for the Versatile daughterboard */
59 #define IB2_CTRL 0x00
60 #define IB2_CTRL_LCD_SD BIT(1) /* 1 = shut down LCD */
61 #define IB2_CTRL_LCD_BL_ON BIT(0)
62 #define IB2_CTRL_LCD_MASK (BIT(0)|BIT(1))
63
64 /**
65 * struct versatile_panel_type - lookup struct for the supported panels
66 */
67 struct versatile_panel_type {
68 /**
69 * @name: the name of this panel
70 */
71 const char *name;
72 /**
73 * @magic: the magic value from the detection register
74 */
75 u32 magic;
76 /**
77 * @mode: the DRM display mode for this panel
78 */
79 struct drm_display_mode mode;
80 /**
81 * @bus_flags: the DRM bus flags for this panel e.g. inverted clock
82 */
83 u32 bus_flags;
84 /**
85 * @width_mm: the panel width in mm
86 */
87 u32 width_mm;
88 /**
89 * @height_mm: the panel height in mm
90 */
91 u32 height_mm;
92 /**
93 * @ib2: the panel may be connected on an IB2 daughterboard
94 */
95 bool ib2;
96 };
97
98 /**
99 * struct versatile_panel - state container for the Versatile panels
100 */
101 struct versatile_panel {
102 /**
103 * @dev: the container device
104 */
105 struct device *dev;
106 /**
107 * @panel: the DRM panel instance for this device
108 */
109 struct drm_panel panel;
110 /**
111 * @panel_type: the Versatile panel type as detected
112 */
113 const struct versatile_panel_type *panel_type;
114 /**
115 * @map: map to the parent syscon where the main register reside
116 */
117 struct regmap *map;
118 /**
119 * @ib2_map: map to the IB2 syscon, if applicable
120 */
121 struct regmap *ib2_map;
122 };
123
124 static const struct versatile_panel_type versatile_panels[] = {
125 /*
126 * Sanyo TM38QV67A02A - 3.8 inch QVGA (320x240) Color TFT
127 * found on the Versatile AB IB1 connector or the Versatile
128 * PB adaptor board connector.
129 */
130 {
131 .name = "Sanyo TM38QV67A02A",
132 .magic = SYS_CLCD_ID_SANYO_3_8,
133 .width_mm = 79,
134 .height_mm = 54,
135 .mode = {
136 .clock = 10000,
137 .hdisplay = 320,
138 .hsync_start = 320 + 6,
139 .hsync_end = 320 + 6 + 6,
140 .htotal = 320 + 6 + 6 + 6,
141 .vdisplay = 240,
142 .vsync_start = 240 + 5,
143 .vsync_end = 240 + 5 + 6,
144 .vtotal = 240 + 5 + 6 + 5,
145 .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
146 },
147 },
148 /*
149 * Sharp LQ084V1DG21 640x480 VGA Color TFT module
150 * found on the Versatile AB IB1 connector or the Versatile
151 * PB adaptor board connector.
152 */
153 {
154 .name = "Sharp LQ084V1DG21",
155 .magic = SYS_CLCD_ID_SHARP_8_4,
156 .width_mm = 171,
157 .height_mm = 130,
158 .mode = {
159 .clock = 25000,
160 .hdisplay = 640,
161 .hsync_start = 640 + 24,
162 .hsync_end = 640 + 24 + 96,
163 .htotal = 640 + 24 + 96 + 24,
164 .vdisplay = 480,
165 .vsync_start = 480 + 11,
166 .vsync_end = 480 + 11 + 2,
167 .vtotal = 480 + 11 + 2 + 32,
168 .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
169 },
170 },
171 /*
172 * Epson L2F50113T00 - 2.2 inch QCIF 176x220 Color TFT
173 * found on the Versatile PB adaptor board connector.
174 */
175 {
176 .name = "Epson L2F50113T00",
177 .magic = SYS_CLCD_ID_EPSON_2_2,
178 .width_mm = 34,
179 .height_mm = 45,
180 .mode = {
181 .clock = 62500,
182 .hdisplay = 176,
183 .hsync_start = 176 + 2,
184 .hsync_end = 176 + 2 + 3,
185 .htotal = 176 + 2 + 3 + 3,
186 .vdisplay = 220,
187 .vsync_start = 220 + 0,
188 .vsync_end = 220 + 0 + 2,
189 .vtotal = 220 + 0 + 2 + 1,
190 .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
191 },
192 .bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
193 },
194 /*
195 * Sanyo ALR252RGT 240x320 portrait display found on the
196 * Versatile AB IB2 daughterboard for GSM prototyping.
197 */
198 {
199 .name = "Sanyo ALR252RGT",
200 .magic = SYS_CLCD_ID_SANYO_2_5,
201 .width_mm = 37,
202 .height_mm = 50,
203 .mode = {
204 .clock = 5400,
205 .hdisplay = 240,
206 .hsync_start = 240 + 10,
207 .hsync_end = 240 + 10 + 10,
208 .htotal = 240 + 10 + 10 + 20,
209 .vdisplay = 320,
210 .vsync_start = 320 + 2,
211 .vsync_end = 320 + 2 + 2,
212 .vtotal = 320 + 2 + 2 + 2,
213 .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
214 },
215 .bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
216 .ib2 = true,
217 },
218 };
219
220 static inline struct versatile_panel *
to_versatile_panel(struct drm_panel * panel)221 to_versatile_panel(struct drm_panel *panel)
222 {
223 return container_of(panel, struct versatile_panel, panel);
224 }
225
versatile_panel_disable(struct drm_panel * panel)226 static int versatile_panel_disable(struct drm_panel *panel)
227 {
228 struct versatile_panel *vpanel = to_versatile_panel(panel);
229
230 /* If we're on an IB2 daughterboard, turn off display */
231 if (vpanel->ib2_map) {
232 dev_dbg(vpanel->dev, "disable IB2 display\n");
233 regmap_update_bits(vpanel->ib2_map,
234 IB2_CTRL,
235 IB2_CTRL_LCD_MASK,
236 IB2_CTRL_LCD_SD);
237 }
238
239 return 0;
240 }
241
versatile_panel_enable(struct drm_panel * panel)242 static int versatile_panel_enable(struct drm_panel *panel)
243 {
244 struct versatile_panel *vpanel = to_versatile_panel(panel);
245
246 /* If we're on an IB2 daughterboard, turn on display */
247 if (vpanel->ib2_map) {
248 dev_dbg(vpanel->dev, "enable IB2 display\n");
249 regmap_update_bits(vpanel->ib2_map,
250 IB2_CTRL,
251 IB2_CTRL_LCD_MASK,
252 IB2_CTRL_LCD_BL_ON);
253 }
254
255 return 0;
256 }
257
versatile_panel_get_modes(struct drm_panel * panel,struct drm_connector * connector)258 static int versatile_panel_get_modes(struct drm_panel *panel,
259 struct drm_connector *connector)
260 {
261 struct versatile_panel *vpanel = to_versatile_panel(panel);
262 struct drm_display_mode *mode;
263
264 connector->display_info.width_mm = vpanel->panel_type->width_mm;
265 connector->display_info.height_mm = vpanel->panel_type->height_mm;
266 connector->display_info.bus_flags = vpanel->panel_type->bus_flags;
267
268 mode = drm_mode_duplicate(connector->dev, &vpanel->panel_type->mode);
269 if (!mode)
270 return -ENOMEM;
271 drm_mode_set_name(mode);
272 mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
273
274 mode->width_mm = vpanel->panel_type->width_mm;
275 mode->height_mm = vpanel->panel_type->height_mm;
276 drm_mode_probed_add(connector, mode);
277
278 return 1;
279 }
280
281 static const struct drm_panel_funcs versatile_panel_drm_funcs = {
282 .disable = versatile_panel_disable,
283 .enable = versatile_panel_enable,
284 .get_modes = versatile_panel_get_modes,
285 };
286
versatile_panel_probe(struct platform_device * pdev)287 static int versatile_panel_probe(struct platform_device *pdev)
288 {
289 struct device *dev = &pdev->dev;
290 struct versatile_panel *vpanel;
291 struct device *parent;
292 struct regmap *map;
293 int ret;
294 u32 val;
295 int i;
296
297 parent = dev->parent;
298 if (!parent) {
299 dev_err(dev, "no parent for versatile panel\n");
300 return -ENODEV;
301 }
302 map = syscon_node_to_regmap(parent->of_node);
303 if (IS_ERR(map)) {
304 dev_err(dev, "no regmap for versatile panel parent\n");
305 return PTR_ERR(map);
306 }
307
308 vpanel = devm_drm_panel_alloc(dev, struct versatile_panel, panel,
309 &versatile_panel_drm_funcs,
310 DRM_MODE_CONNECTOR_DPI);
311 if (IS_ERR(vpanel))
312 return PTR_ERR(vpanel);
313
314 ret = regmap_read(map, SYS_CLCD, &val);
315 if (ret) {
316 dev_err(dev, "cannot access syscon regs\n");
317 return ret;
318 }
319
320 val &= SYS_CLCD_CLCDID_MASK;
321
322 for (i = 0; i < ARRAY_SIZE(versatile_panels); i++) {
323 const struct versatile_panel_type *pt;
324
325 pt = &versatile_panels[i];
326 if (pt->magic == val) {
327 vpanel->panel_type = pt;
328 break;
329 }
330 }
331
332 /* No panel detected or VGA, let's leave this show */
333 if (i == ARRAY_SIZE(versatile_panels)) {
334 dev_info(dev, "no panel detected\n");
335 return -ENODEV;
336 }
337
338 dev_info(dev, "detected: %s\n", vpanel->panel_type->name);
339 vpanel->dev = dev;
340 vpanel->map = map;
341
342 /* Check if the panel is mounted on an IB2 daughterboard */
343 if (vpanel->panel_type->ib2) {
344 vpanel->ib2_map = syscon_regmap_lookup_by_compatible(
345 "arm,versatile-ib2-syscon");
346 if (IS_ERR(vpanel->ib2_map))
347 vpanel->ib2_map = NULL;
348 else
349 dev_info(dev, "panel mounted on IB2 daughterboard\n");
350 }
351
352 drm_panel_add(&vpanel->panel);
353
354 return 0;
355 }
356
357 static const struct of_device_id versatile_panel_match[] = {
358 { .compatible = "arm,versatile-tft-panel", },
359 {},
360 };
361 MODULE_DEVICE_TABLE(of, versatile_panel_match);
362
363 static struct platform_driver versatile_panel_driver = {
364 .probe = versatile_panel_probe,
365 .driver = {
366 .name = "versatile-tft-panel",
367 .of_match_table = versatile_panel_match,
368 },
369 };
370 module_platform_driver(versatile_panel_driver);
371
372 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
373 MODULE_DESCRIPTION("ARM Versatile panel driver");
374 MODULE_LICENSE("GPL v2");
375