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/mod_devicetable.h>
34 #include <linux/module.h>
35 #include <linux/platform_device.h>
36 #include <linux/regmap.h>
37
38 #include <video/of_videomode.h>
39 #include <video/videomode.h>
40
41 #include <drm/drm_modes.h>
42 #include <drm/drm_panel.h>
43
44 /*
45 * This configuration register in the Versatile and RealView
46 * family is uniformly present but appears more and more
47 * unutilized starting with the RealView series.
48 */
49 #define SYS_CLCD 0x50
50
51 /* The Versatile can detect the connected panel type */
52 #define SYS_CLCD_CLCDID_MASK (BIT(8)|BIT(9)|BIT(10)|BIT(11)|BIT(12))
53 #define SYS_CLCD_ID_SANYO_3_8 (0x00 << 8)
54 #define SYS_CLCD_ID_SHARP_8_4 (0x01 << 8)
55 #define SYS_CLCD_ID_EPSON_2_2 (0x02 << 8)
56 #define SYS_CLCD_ID_SANYO_2_5 (0x07 << 8)
57 #define SYS_CLCD_ID_VGA (0x1f << 8)
58
59 /* IB2 control register for the Versatile daughterboard */
60 #define IB2_CTRL 0x00
61 #define IB2_CTRL_LCD_SD BIT(1) /* 1 = shut down LCD */
62 #define IB2_CTRL_LCD_BL_ON BIT(0)
63 #define IB2_CTRL_LCD_MASK (BIT(0)|BIT(1))
64
65 /**
66 * struct versatile_panel_type - lookup struct for the supported panels
67 */
68 struct versatile_panel_type {
69 /**
70 * @name: the name of this panel
71 */
72 const char *name;
73 /**
74 * @magic: the magic value from the detection register
75 */
76 u32 magic;
77 /**
78 * @mode: the DRM display mode for this panel
79 */
80 struct drm_display_mode mode;
81 /**
82 * @bus_flags: the DRM bus flags for this panel e.g. inverted clock
83 */
84 u32 bus_flags;
85 /**
86 * @width_mm: the panel width in mm
87 */
88 u32 width_mm;
89 /**
90 * @height_mm: the panel height in mm
91 */
92 u32 height_mm;
93 /**
94 * @ib2: the panel may be connected on an IB2 daughterboard
95 */
96 bool ib2;
97 };
98
99 /**
100 * struct versatile_panel - state container for the Versatile panels
101 */
102 struct versatile_panel {
103 /**
104 * @dev: the container device
105 */
106 struct device *dev;
107 /**
108 * @panel: the DRM panel instance for this device
109 */
110 struct drm_panel panel;
111 /**
112 * @panel_type: the Versatile panel type as detected
113 */
114 const struct versatile_panel_type *panel_type;
115 /**
116 * @map: map to the parent syscon where the main register reside
117 */
118 struct regmap *map;
119 /**
120 * @ib2_map: map to the IB2 syscon, if applicable
121 */
122 struct regmap *ib2_map;
123 };
124
125 static const struct versatile_panel_type versatile_panels[] = {
126 /*
127 * Sanyo TM38QV67A02A - 3.8 inch QVGA (320x240) Color TFT
128 * found on the Versatile AB IB1 connector or the Versatile
129 * PB adaptor board connector.
130 */
131 {
132 .name = "Sanyo TM38QV67A02A",
133 .magic = SYS_CLCD_ID_SANYO_3_8,
134 .width_mm = 79,
135 .height_mm = 54,
136 .mode = {
137 .clock = 10000,
138 .hdisplay = 320,
139 .hsync_start = 320 + 6,
140 .hsync_end = 320 + 6 + 6,
141 .htotal = 320 + 6 + 6 + 6,
142 .vdisplay = 240,
143 .vsync_start = 240 + 5,
144 .vsync_end = 240 + 5 + 6,
145 .vtotal = 240 + 5 + 6 + 5,
146 .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
147 },
148 },
149 /*
150 * Sharp LQ084V1DG21 640x480 VGA Color TFT module
151 * found on the Versatile AB IB1 connector or the Versatile
152 * PB adaptor board connector.
153 */
154 {
155 .name = "Sharp LQ084V1DG21",
156 .magic = SYS_CLCD_ID_SHARP_8_4,
157 .width_mm = 171,
158 .height_mm = 130,
159 .mode = {
160 .clock = 25000,
161 .hdisplay = 640,
162 .hsync_start = 640 + 24,
163 .hsync_end = 640 + 24 + 96,
164 .htotal = 640 + 24 + 96 + 24,
165 .vdisplay = 480,
166 .vsync_start = 480 + 11,
167 .vsync_end = 480 + 11 + 2,
168 .vtotal = 480 + 11 + 2 + 32,
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 .flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
192 },
193 .bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
194 },
195 /*
196 * Sanyo ALR252RGT 240x320 portrait display found on the
197 * Versatile AB IB2 daughterboard for GSM prototyping.
198 */
199 {
200 .name = "Sanyo ALR252RGT",
201 .magic = SYS_CLCD_ID_SANYO_2_5,
202 .width_mm = 37,
203 .height_mm = 50,
204 .mode = {
205 .clock = 5400,
206 .hdisplay = 240,
207 .hsync_start = 240 + 10,
208 .hsync_end = 240 + 10 + 10,
209 .htotal = 240 + 10 + 10 + 20,
210 .vdisplay = 320,
211 .vsync_start = 320 + 2,
212 .vsync_end = 320 + 2 + 2,
213 .vtotal = 320 + 2 + 2 + 2,
214 .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
215 },
216 .bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
217 .ib2 = true,
218 },
219 };
220
221 static inline struct versatile_panel *
to_versatile_panel(struct drm_panel * panel)222 to_versatile_panel(struct drm_panel *panel)
223 {
224 return container_of(panel, struct versatile_panel, panel);
225 }
226
versatile_panel_disable(struct drm_panel * panel)227 static int versatile_panel_disable(struct drm_panel *panel)
228 {
229 struct versatile_panel *vpanel = to_versatile_panel(panel);
230
231 /* If we're on an IB2 daughterboard, turn off display */
232 if (vpanel->ib2_map) {
233 dev_dbg(vpanel->dev, "disable IB2 display\n");
234 regmap_update_bits(vpanel->ib2_map,
235 IB2_CTRL,
236 IB2_CTRL_LCD_MASK,
237 IB2_CTRL_LCD_SD);
238 }
239
240 return 0;
241 }
242
versatile_panel_enable(struct drm_panel * panel)243 static int versatile_panel_enable(struct drm_panel *panel)
244 {
245 struct versatile_panel *vpanel = to_versatile_panel(panel);
246
247 /* If we're on an IB2 daughterboard, turn on display */
248 if (vpanel->ib2_map) {
249 dev_dbg(vpanel->dev, "enable IB2 display\n");
250 regmap_update_bits(vpanel->ib2_map,
251 IB2_CTRL,
252 IB2_CTRL_LCD_MASK,
253 IB2_CTRL_LCD_BL_ON);
254 }
255
256 return 0;
257 }
258
versatile_panel_get_modes(struct drm_panel * panel,struct drm_connector * connector)259 static int versatile_panel_get_modes(struct drm_panel *panel,
260 struct drm_connector *connector)
261 {
262 struct versatile_panel *vpanel = to_versatile_panel(panel);
263 struct drm_display_mode *mode;
264
265 connector->display_info.width_mm = vpanel->panel_type->width_mm;
266 connector->display_info.height_mm = vpanel->panel_type->height_mm;
267 connector->display_info.bus_flags = vpanel->panel_type->bus_flags;
268
269 mode = drm_mode_duplicate(connector->dev, &vpanel->panel_type->mode);
270 if (!mode)
271 return -ENOMEM;
272 drm_mode_set_name(mode);
273 mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
274
275 mode->width_mm = vpanel->panel_type->width_mm;
276 mode->height_mm = vpanel->panel_type->height_mm;
277 drm_mode_probed_add(connector, mode);
278
279 return 1;
280 }
281
282 static const struct drm_panel_funcs versatile_panel_drm_funcs = {
283 .disable = versatile_panel_disable,
284 .enable = versatile_panel_enable,
285 .get_modes = versatile_panel_get_modes,
286 };
287
versatile_panel_probe(struct platform_device * pdev)288 static int versatile_panel_probe(struct platform_device *pdev)
289 {
290 struct device *dev = &pdev->dev;
291 struct versatile_panel *vpanel;
292 struct device *parent;
293 struct regmap *map;
294 int ret;
295 u32 val;
296 int i;
297
298 parent = dev->parent;
299 if (!parent) {
300 dev_err(dev, "no parent for versatile panel\n");
301 return -ENODEV;
302 }
303 map = syscon_node_to_regmap(parent->of_node);
304 if (IS_ERR(map)) {
305 dev_err(dev, "no regmap for versatile panel parent\n");
306 return PTR_ERR(map);
307 }
308
309 vpanel = devm_kzalloc(dev, sizeof(*vpanel), GFP_KERNEL);
310 if (!vpanel)
311 return -ENOMEM;
312
313 ret = regmap_read(map, SYS_CLCD, &val);
314 if (ret) {
315 dev_err(dev, "cannot access syscon regs\n");
316 return ret;
317 }
318
319 val &= SYS_CLCD_CLCDID_MASK;
320
321 for (i = 0; i < ARRAY_SIZE(versatile_panels); i++) {
322 const struct versatile_panel_type *pt;
323
324 pt = &versatile_panels[i];
325 if (pt->magic == val) {
326 vpanel->panel_type = pt;
327 break;
328 }
329 }
330
331 /* No panel detected or VGA, let's leave this show */
332 if (i == ARRAY_SIZE(versatile_panels)) {
333 dev_info(dev, "no panel detected\n");
334 return -ENODEV;
335 }
336
337 dev_info(dev, "detected: %s\n", vpanel->panel_type->name);
338 vpanel->dev = dev;
339 vpanel->map = map;
340
341 /* Check if the panel is mounted on an IB2 daughterboard */
342 if (vpanel->panel_type->ib2) {
343 vpanel->ib2_map = syscon_regmap_lookup_by_compatible(
344 "arm,versatile-ib2-syscon");
345 if (IS_ERR(vpanel->ib2_map))
346 vpanel->ib2_map = NULL;
347 else
348 dev_info(dev, "panel mounted on IB2 daughterboard\n");
349 }
350
351 drm_panel_init(&vpanel->panel, dev, &versatile_panel_drm_funcs,
352 DRM_MODE_CONNECTOR_DPI);
353
354 drm_panel_add(&vpanel->panel);
355
356 return 0;
357 }
358
359 static const struct of_device_id versatile_panel_match[] = {
360 { .compatible = "arm,versatile-tft-panel", },
361 {},
362 };
363 MODULE_DEVICE_TABLE(of, versatile_panel_match);
364
365 static struct platform_driver versatile_panel_driver = {
366 .probe = versatile_panel_probe,
367 .driver = {
368 .name = "versatile-tft-panel",
369 .of_match_table = versatile_panel_match,
370 },
371 };
372 module_platform_driver(versatile_panel_driver);
373
374 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
375 MODULE_DESCRIPTION("ARM Versatile panel driver");
376 MODULE_LICENSE("GPL v2");
377