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 #include <drm/drmP.h>
29 #include <drm/drm_panel.h>
30
31 #include <linux/bitops.h>
32 #include <linux/init.h>
33 #include <linux/kernel.h>
34 #include <linux/mfd/syscon.h>
35 #include <linux/module.h>
36 #include <linux/platform_device.h>
37 #include <linux/regmap.h>
38
39 #include <video/of_videomode.h>
40 #include <video/videomode.h>
41
42 /*
43 * This configuration register in the Versatile and RealView
44 * family is uniformly present but appears more and more
45 * unutilized starting with the RealView series.
46 */
47 #define SYS_CLCD 0x50
48
49 /* The Versatile can detect the connected panel type */
50 #define SYS_CLCD_CLCDID_MASK (BIT(8)|BIT(9)|BIT(10)|BIT(11)|BIT(12))
51 #define SYS_CLCD_ID_SANYO_3_8 (0x00 << 8)
52 #define SYS_CLCD_ID_SHARP_8_4 (0x01 << 8)
53 #define SYS_CLCD_ID_EPSON_2_2 (0x02 << 8)
54 #define SYS_CLCD_ID_SANYO_2_5 (0x07 << 8)
55 #define SYS_CLCD_ID_VGA (0x1f << 8)
56
57 /* IB2 control register for the Versatile daughterboard */
58 #define IB2_CTRL 0x00
59 #define IB2_CTRL_LCD_SD BIT(1) /* 1 = shut down LCD */
60 #define IB2_CTRL_LCD_BL_ON BIT(0)
61 #define IB2_CTRL_LCD_MASK (BIT(0)|BIT(1))
62
63 /**
64 * struct versatile_panel_type - lookup struct for the supported panels
65 */
66 struct versatile_panel_type {
67 /**
68 * @name: the name of this panel
69 */
70 const char *name;
71 /**
72 * @magic: the magic value from the detection register
73 */
74 u32 magic;
75 /**
76 * @mode: the DRM display mode for this panel
77 */
78 struct drm_display_mode mode;
79 /**
80 * @bus_flags: the DRM bus flags for this panel e.g. inverted clock
81 */
82 u32 bus_flags;
83 /**
84 * @width_mm: the panel width in mm
85 */
86 u32 width_mm;
87 /**
88 * @height_mm: the panel height in mm
89 */
90 u32 height_mm;
91 /**
92 * @ib2: the panel may be connected on an IB2 daughterboard
93 */
94 bool ib2;
95 };
96
97 /**
98 * struct versatile_panel - state container for the Versatile panels
99 */
100 struct versatile_panel {
101 /**
102 * @dev: the container device
103 */
104 struct device *dev;
105 /**
106 * @panel: the DRM panel instance for this device
107 */
108 struct drm_panel panel;
109 /**
110 * @panel_type: the Versatile panel type as detected
111 */
112 const struct versatile_panel_type *panel_type;
113 /**
114 * @map: map to the parent syscon where the main register reside
115 */
116 struct regmap *map;
117 /**
118 * @ib2_map: map to the IB2 syscon, if applicable
119 */
120 struct regmap *ib2_map;
121 };
122
123 static const struct versatile_panel_type versatile_panels[] = {
124 /*
125 * Sanyo TM38QV67A02A - 3.8 inch QVGA (320x240) Color TFT
126 * found on the Versatile AB IB1 connector or the Versatile
127 * PB adaptor board connector.
128 */
129 {
130 .name = "Sanyo TM38QV67A02A",
131 .magic = SYS_CLCD_ID_SANYO_3_8,
132 .width_mm = 79,
133 .height_mm = 54,
134 .mode = {
135 .clock = 10000,
136 .hdisplay = 320,
137 .hsync_start = 320 + 6,
138 .hsync_end = 320 + 6 + 6,
139 .htotal = 320 + 6 + 6 + 6,
140 .vdisplay = 240,
141 .vsync_start = 240 + 5,
142 .vsync_end = 240 + 5 + 6,
143 .vtotal = 240 + 5 + 6 + 5,
144 .vrefresh = 116,
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 .vrefresh = 60,
169 .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
170 },
171 },
172 /*
173 * Epson L2F50113T00 - 2.2 inch QCIF 176x220 Color TFT
174 * found on the Versatile PB adaptor board connector.
175 */
176 {
177 .name = "Epson L2F50113T00",
178 .magic = SYS_CLCD_ID_EPSON_2_2,
179 .width_mm = 34,
180 .height_mm = 45,
181 .mode = {
182 .clock = 62500,
183 .hdisplay = 176,
184 .hsync_start = 176 + 2,
185 .hsync_end = 176 + 2 + 3,
186 .htotal = 176 + 2 + 3 + 3,
187 .vdisplay = 220,
188 .vsync_start = 220 + 0,
189 .vsync_end = 220 + 0 + 2,
190 .vtotal = 220 + 0 + 2 + 1,
191 .vrefresh = 390,
192 .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
193 },
194 .bus_flags = DRM_BUS_FLAG_PIXDATA_NEGEDGE,
195 },
196 /*
197 * Sanyo ALR252RGT 240x320 portrait display found on the
198 * Versatile AB IB2 daughterboard for GSM prototyping.
199 */
200 {
201 .name = "Sanyo ALR252RGT",
202 .magic = SYS_CLCD_ID_SANYO_2_5,
203 .width_mm = 37,
204 .height_mm = 50,
205 .mode = {
206 .clock = 5400,
207 .hdisplay = 240,
208 .hsync_start = 240 + 10,
209 .hsync_end = 240 + 10 + 10,
210 .htotal = 240 + 10 + 10 + 20,
211 .vdisplay = 320,
212 .vsync_start = 320 + 2,
213 .vsync_end = 320 + 2 + 2,
214 .vtotal = 320 + 2 + 2 + 2,
215 .vrefresh = 116,
216 .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
217 },
218 .bus_flags = DRM_BUS_FLAG_PIXDATA_NEGEDGE,
219 .ib2 = true,
220 },
221 };
222
223 static inline struct versatile_panel *
to_versatile_panel(struct drm_panel * panel)224 to_versatile_panel(struct drm_panel *panel)
225 {
226 return container_of(panel, struct versatile_panel, panel);
227 }
228
versatile_panel_disable(struct drm_panel * panel)229 static int versatile_panel_disable(struct drm_panel *panel)
230 {
231 struct versatile_panel *vpanel = to_versatile_panel(panel);
232
233 /* If we're on an IB2 daughterboard, turn off display */
234 if (vpanel->ib2_map) {
235 dev_dbg(vpanel->dev, "disable IB2 display\n");
236 regmap_update_bits(vpanel->ib2_map,
237 IB2_CTRL,
238 IB2_CTRL_LCD_MASK,
239 IB2_CTRL_LCD_SD);
240 }
241
242 return 0;
243 }
244
versatile_panel_enable(struct drm_panel * panel)245 static int versatile_panel_enable(struct drm_panel *panel)
246 {
247 struct versatile_panel *vpanel = to_versatile_panel(panel);
248
249 /* If we're on an IB2 daughterboard, turn on display */
250 if (vpanel->ib2_map) {
251 dev_dbg(vpanel->dev, "enable IB2 display\n");
252 regmap_update_bits(vpanel->ib2_map,
253 IB2_CTRL,
254 IB2_CTRL_LCD_MASK,
255 IB2_CTRL_LCD_BL_ON);
256 }
257
258 return 0;
259 }
260
versatile_panel_get_modes(struct drm_panel * panel)261 static int versatile_panel_get_modes(struct drm_panel *panel)
262 {
263 struct drm_connector *connector = panel->connector;
264 struct versatile_panel *vpanel = to_versatile_panel(panel);
265 struct drm_display_mode *mode;
266
267 strncpy(connector->display_info.name, vpanel->panel_type->name,
268 DRM_DISPLAY_INFO_LEN);
269 connector->display_info.width_mm = vpanel->panel_type->width_mm;
270 connector->display_info.height_mm = vpanel->panel_type->height_mm;
271 connector->display_info.bus_flags = vpanel->panel_type->bus_flags;
272
273 mode = drm_mode_duplicate(panel->drm, &vpanel->panel_type->mode);
274 drm_mode_set_name(mode);
275 mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
276
277 mode->width_mm = vpanel->panel_type->width_mm;
278 mode->height_mm = vpanel->panel_type->height_mm;
279 drm_mode_probed_add(connector, mode);
280
281 return 1;
282 }
283
284 static const struct drm_panel_funcs versatile_panel_drm_funcs = {
285 .disable = versatile_panel_disable,
286 .enable = versatile_panel_enable,
287 .get_modes = versatile_panel_get_modes,
288 };
289
versatile_panel_probe(struct platform_device * pdev)290 static int versatile_panel_probe(struct platform_device *pdev)
291 {
292 struct device *dev = &pdev->dev;
293 struct versatile_panel *vpanel;
294 struct device *parent;
295 struct regmap *map;
296 int ret;
297 u32 val;
298 int i;
299
300 parent = dev->parent;
301 if (!parent) {
302 dev_err(dev, "no parent for versatile panel\n");
303 return -ENODEV;
304 }
305 map = syscon_node_to_regmap(parent->of_node);
306 if (IS_ERR(map)) {
307 dev_err(dev, "no regmap for versatile panel parent\n");
308 return PTR_ERR(map);
309 }
310
311 vpanel = devm_kzalloc(dev, sizeof(*vpanel), GFP_KERNEL);
312 if (!vpanel)
313 return -ENOMEM;
314
315 ret = regmap_read(map, SYS_CLCD, &val);
316 if (ret) {
317 dev_err(dev, "cannot access syscon regs\n");
318 return ret;
319 }
320
321 val &= SYS_CLCD_CLCDID_MASK;
322
323 for (i = 0; i < ARRAY_SIZE(versatile_panels); i++) {
324 const struct versatile_panel_type *pt;
325
326 pt = &versatile_panels[i];
327 if (pt->magic == val) {
328 vpanel->panel_type = pt;
329 break;
330 }
331 }
332
333 /* No panel detected or VGA, let's leave this show */
334 if (i == ARRAY_SIZE(versatile_panels)) {
335 dev_info(dev, "no panel detected\n");
336 return -ENODEV;
337 }
338
339 dev_info(dev, "detected: %s\n", vpanel->panel_type->name);
340 vpanel->dev = dev;
341 vpanel->map = map;
342
343 /* Check if the panel is mounted on an IB2 daughterboard */
344 if (vpanel->panel_type->ib2) {
345 vpanel->ib2_map = syscon_regmap_lookup_by_compatible(
346 "arm,versatile-ib2-syscon");
347 if (IS_ERR(vpanel->ib2_map))
348 vpanel->ib2_map = NULL;
349 else
350 dev_info(dev, "panel mounted on IB2 daughterboard\n");
351 }
352
353 drm_panel_init(&vpanel->panel);
354 vpanel->panel.dev = dev;
355 vpanel->panel.funcs = &versatile_panel_drm_funcs;
356
357 return drm_panel_add(&vpanel->panel);
358 }
359
360 static const struct of_device_id versatile_panel_match[] = {
361 { .compatible = "arm,versatile-tft-panel", },
362 {},
363 };
364 MODULE_DEVICE_TABLE(of, versatile_panel_match);
365
366 static struct platform_driver versatile_panel_driver = {
367 .probe = versatile_panel_probe,
368 .driver = {
369 .name = "versatile-tft-panel",
370 .of_match_table = versatile_panel_match,
371 },
372 };
373 module_platform_driver(versatile_panel_driver);
374
375 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
376 MODULE_DESCRIPTION("ARM Versatile panel driver");
377 MODULE_LICENSE("GPL v2");
378
