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 */
68struct 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 */
102struct 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
125static 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
221static inline struct versatile_panel *
222to_versatile_panel(struct drm_panel *panel)
223{
224	return container_of(panel, struct versatile_panel, panel);
225}
226
227static 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
243static 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
259static 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
282static 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
288static 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
359static const struct of_device_id versatile_panel_match[] = {
360	{ .compatible = "arm,versatile-tft-panel", },
361	{},
362};
363MODULE_DEVICE_TABLE(of, versatile_panel_match);
364
365static 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};
372module_platform_driver(versatile_panel_driver);
373
374MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
375MODULE_DESCRIPTION("ARM Versatile panel driver");
376MODULE_LICENSE("GPL v2");
377