xref: /openbmc/linux/drivers/gpu/drm/i2c/sil164_drv.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
1 /*
2  * Copyright (C) 2010 Francisco Jerez.
3  * All Rights Reserved.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining
6  * a copy of this software and associated documentation files (the
7  * "Software"), to deal in the Software without restriction, including
8  * without limitation the rights to use, copy, modify, merge, publish,
9  * distribute, sublicense, and/or sell copies of the Software, and to
10  * permit persons to whom the Software is furnished to do so, subject to
11  * the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the
14  * next paragraph) shall be included in all copies or substantial
15  * portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
20  * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
21  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24  *
25  */
26 
27 #include "drmP.h"
28 #include "drm_crtc_helper.h"
29 #include "drm_encoder_slave.h"
30 #include "i2c/sil164.h"
31 
32 struct sil164_priv {
33 	struct sil164_encoder_params config;
34 	struct i2c_client *duallink_slave;
35 
36 	uint8_t saved_state[0x10];
37 	uint8_t saved_slave_state[0x10];
38 };
39 
40 #define to_sil164_priv(x) \
41 	((struct sil164_priv *)to_encoder_slave(x)->slave_priv)
42 
43 #define sil164_dbg(client, format, ...) do {				\
44 		if (drm_debug & DRM_UT_KMS)				\
45 			dev_printk(KERN_DEBUG, &client->dev,		\
46 				   "%s: " format, __func__, ## __VA_ARGS__); \
47 	} while (0)
48 #define sil164_info(client, format, ...)		\
49 	dev_info(&client->dev, format, __VA_ARGS__)
50 #define sil164_err(client, format, ...)			\
51 	dev_err(&client->dev, format, __VA_ARGS__)
52 
53 #define SIL164_I2C_ADDR_MASTER			0x38
54 #define SIL164_I2C_ADDR_SLAVE			0x39
55 
56 /* HW register definitions */
57 
58 #define SIL164_VENDOR_LO			0x0
59 #define SIL164_VENDOR_HI			0x1
60 #define SIL164_DEVICE_LO			0x2
61 #define SIL164_DEVICE_HI			0x3
62 #define SIL164_REVISION				0x4
63 #define SIL164_FREQ_MIN				0x6
64 #define SIL164_FREQ_MAX				0x7
65 #define SIL164_CONTROL0				0x8
66 #  define SIL164_CONTROL0_POWER_ON		0x01
67 #  define SIL164_CONTROL0_EDGE_RISING		0x02
68 #  define SIL164_CONTROL0_INPUT_24BIT		0x04
69 #  define SIL164_CONTROL0_DUAL_EDGE		0x08
70 #  define SIL164_CONTROL0_HSYNC_ON		0x10
71 #  define SIL164_CONTROL0_VSYNC_ON		0x20
72 #define SIL164_DETECT				0x9
73 #  define SIL164_DETECT_INTR_STAT		0x01
74 #  define SIL164_DETECT_HOTPLUG_STAT		0x02
75 #  define SIL164_DETECT_RECEIVER_STAT		0x04
76 #  define SIL164_DETECT_INTR_MODE_RECEIVER	0x00
77 #  define SIL164_DETECT_INTR_MODE_HOTPLUG	0x08
78 #  define SIL164_DETECT_OUT_MODE_HIGH		0x00
79 #  define SIL164_DETECT_OUT_MODE_INTR		0x10
80 #  define SIL164_DETECT_OUT_MODE_RECEIVER	0x20
81 #  define SIL164_DETECT_OUT_MODE_HOTPLUG	0x30
82 #  define SIL164_DETECT_VSWING_STAT		0x80
83 #define SIL164_CONTROL1				0xa
84 #  define SIL164_CONTROL1_DESKEW_ENABLE		0x10
85 #  define SIL164_CONTROL1_DESKEW_INCR_SHIFT	5
86 #define SIL164_GPIO				0xb
87 #define SIL164_CONTROL2				0xc
88 #  define SIL164_CONTROL2_FILTER_ENABLE		0x01
89 #  define SIL164_CONTROL2_FILTER_SETTING_SHIFT	1
90 #  define SIL164_CONTROL2_DUALLINK_MASTER	0x40
91 #  define SIL164_CONTROL2_SYNC_CONT		0x80
92 #define SIL164_DUALLINK				0xd
93 #  define SIL164_DUALLINK_ENABLE		0x10
94 #  define SIL164_DUALLINK_SKEW_SHIFT		5
95 #define SIL164_PLLZONE				0xe
96 #  define SIL164_PLLZONE_STAT			0x08
97 #  define SIL164_PLLZONE_FORCE_ON		0x10
98 #  define SIL164_PLLZONE_FORCE_HIGH		0x20
99 
100 /* HW access functions */
101 
102 static void
103 sil164_write(struct i2c_client *client, uint8_t addr, uint8_t val)
104 {
105 	uint8_t buf[] = {addr, val};
106 	int ret;
107 
108 	ret = i2c_master_send(client, buf, ARRAY_SIZE(buf));
109 	if (ret < 0)
110 		sil164_err(client, "Error %d writing to subaddress 0x%x\n",
111 			   ret, addr);
112 }
113 
114 static uint8_t
115 sil164_read(struct i2c_client *client, uint8_t addr)
116 {
117 	uint8_t val;
118 	int ret;
119 
120 	ret = i2c_master_send(client, &addr, sizeof(addr));
121 	if (ret < 0)
122 		goto fail;
123 
124 	ret = i2c_master_recv(client, &val, sizeof(val));
125 	if (ret < 0)
126 		goto fail;
127 
128 	return val;
129 
130 fail:
131 	sil164_err(client, "Error %d reading from subaddress 0x%x\n",
132 		   ret, addr);
133 	return 0;
134 }
135 
136 static void
137 sil164_save_state(struct i2c_client *client, uint8_t *state)
138 {
139 	int i;
140 
141 	for (i = 0x8; i <= 0xe; i++)
142 		state[i] = sil164_read(client, i);
143 }
144 
145 static void
146 sil164_restore_state(struct i2c_client *client, uint8_t *state)
147 {
148 	int i;
149 
150 	for (i = 0x8; i <= 0xe; i++)
151 		sil164_write(client, i, state[i]);
152 }
153 
154 static void
155 sil164_set_power_state(struct i2c_client *client, bool on)
156 {
157 	uint8_t control0 = sil164_read(client, SIL164_CONTROL0);
158 
159 	if (on)
160 		control0 |= SIL164_CONTROL0_POWER_ON;
161 	else
162 		control0 &= ~SIL164_CONTROL0_POWER_ON;
163 
164 	sil164_write(client, SIL164_CONTROL0, control0);
165 }
166 
167 static void
168 sil164_init_state(struct i2c_client *client,
169 		  struct sil164_encoder_params *config,
170 		  bool duallink)
171 {
172 	sil164_write(client, SIL164_CONTROL0,
173 		     SIL164_CONTROL0_HSYNC_ON |
174 		     SIL164_CONTROL0_VSYNC_ON |
175 		     (config->input_edge ? SIL164_CONTROL0_EDGE_RISING : 0) |
176 		     (config->input_width ? SIL164_CONTROL0_INPUT_24BIT : 0) |
177 		     (config->input_dual ? SIL164_CONTROL0_DUAL_EDGE : 0));
178 
179 	sil164_write(client, SIL164_DETECT,
180 		     SIL164_DETECT_INTR_STAT |
181 		     SIL164_DETECT_OUT_MODE_RECEIVER);
182 
183 	sil164_write(client, SIL164_CONTROL1,
184 		     (config->input_skew ? SIL164_CONTROL1_DESKEW_ENABLE : 0) |
185 		     (((config->input_skew + 4) & 0x7)
186 		      << SIL164_CONTROL1_DESKEW_INCR_SHIFT));
187 
188 	sil164_write(client, SIL164_CONTROL2,
189 		     SIL164_CONTROL2_SYNC_CONT |
190 		     (config->pll_filter ? 0 : SIL164_CONTROL2_FILTER_ENABLE) |
191 		     (4 << SIL164_CONTROL2_FILTER_SETTING_SHIFT));
192 
193 	sil164_write(client, SIL164_PLLZONE, 0);
194 
195 	if (duallink)
196 		sil164_write(client, SIL164_DUALLINK,
197 			     SIL164_DUALLINK_ENABLE |
198 			     (((config->duallink_skew + 4) & 0x7)
199 			      << SIL164_DUALLINK_SKEW_SHIFT));
200 	else
201 		sil164_write(client, SIL164_DUALLINK, 0);
202 }
203 
204 /* DRM encoder functions */
205 
206 static void
207 sil164_encoder_set_config(struct drm_encoder *encoder, void *params)
208 {
209 	struct sil164_priv *priv = to_sil164_priv(encoder);
210 
211 	priv->config = *(struct sil164_encoder_params *)params;
212 }
213 
214 static void
215 sil164_encoder_dpms(struct drm_encoder *encoder, int mode)
216 {
217 	struct sil164_priv *priv = to_sil164_priv(encoder);
218 	bool on = (mode == DRM_MODE_DPMS_ON);
219 	bool duallink = (on && encoder->crtc->mode.clock > 165000);
220 
221 	sil164_set_power_state(drm_i2c_encoder_get_client(encoder), on);
222 
223 	if (priv->duallink_slave)
224 		sil164_set_power_state(priv->duallink_slave, duallink);
225 }
226 
227 static void
228 sil164_encoder_save(struct drm_encoder *encoder)
229 {
230 	struct sil164_priv *priv = to_sil164_priv(encoder);
231 
232 	sil164_save_state(drm_i2c_encoder_get_client(encoder),
233 			  priv->saved_state);
234 
235 	if (priv->duallink_slave)
236 		sil164_save_state(priv->duallink_slave,
237 				  priv->saved_slave_state);
238 }
239 
240 static void
241 sil164_encoder_restore(struct drm_encoder *encoder)
242 {
243 	struct sil164_priv *priv = to_sil164_priv(encoder);
244 
245 	sil164_restore_state(drm_i2c_encoder_get_client(encoder),
246 			     priv->saved_state);
247 
248 	if (priv->duallink_slave)
249 		sil164_restore_state(priv->duallink_slave,
250 				     priv->saved_slave_state);
251 }
252 
253 static bool
254 sil164_encoder_mode_fixup(struct drm_encoder *encoder,
255 			  struct drm_display_mode *mode,
256 			  struct drm_display_mode *adjusted_mode)
257 {
258 	return true;
259 }
260 
261 static int
262 sil164_encoder_mode_valid(struct drm_encoder *encoder,
263 			  struct drm_display_mode *mode)
264 {
265 	struct sil164_priv *priv = to_sil164_priv(encoder);
266 
267 	if (mode->clock < 32000)
268 		return MODE_CLOCK_LOW;
269 
270 	if (mode->clock > 330000 ||
271 	    (mode->clock > 165000 && !priv->duallink_slave))
272 		return MODE_CLOCK_HIGH;
273 
274 	return MODE_OK;
275 }
276 
277 static void
278 sil164_encoder_mode_set(struct drm_encoder *encoder,
279 			struct drm_display_mode *mode,
280 			struct drm_display_mode *adjusted_mode)
281 {
282 	struct sil164_priv *priv = to_sil164_priv(encoder);
283 	bool duallink = adjusted_mode->clock > 165000;
284 
285 	sil164_init_state(drm_i2c_encoder_get_client(encoder),
286 			  &priv->config, duallink);
287 
288 	if (priv->duallink_slave)
289 		sil164_init_state(priv->duallink_slave,
290 				  &priv->config, duallink);
291 
292 	sil164_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
293 }
294 
295 static enum drm_connector_status
296 sil164_encoder_detect(struct drm_encoder *encoder,
297 		      struct drm_connector *connector)
298 {
299 	struct i2c_client *client = drm_i2c_encoder_get_client(encoder);
300 
301 	if (sil164_read(client, SIL164_DETECT) & SIL164_DETECT_HOTPLUG_STAT)
302 		return connector_status_connected;
303 	else
304 		return connector_status_disconnected;
305 }
306 
307 static int
308 sil164_encoder_get_modes(struct drm_encoder *encoder,
309 			 struct drm_connector *connector)
310 {
311 	return 0;
312 }
313 
314 static int
315 sil164_encoder_create_resources(struct drm_encoder *encoder,
316 				struct drm_connector *connector)
317 {
318 	return 0;
319 }
320 
321 static int
322 sil164_encoder_set_property(struct drm_encoder *encoder,
323 			    struct drm_connector *connector,
324 			    struct drm_property *property,
325 			    uint64_t val)
326 {
327 	return 0;
328 }
329 
330 static void
331 sil164_encoder_destroy(struct drm_encoder *encoder)
332 {
333 	struct sil164_priv *priv = to_sil164_priv(encoder);
334 
335 	if (priv->duallink_slave)
336 		i2c_unregister_device(priv->duallink_slave);
337 
338 	kfree(priv);
339 	drm_i2c_encoder_destroy(encoder);
340 }
341 
342 static struct drm_encoder_slave_funcs sil164_encoder_funcs = {
343 	.set_config = sil164_encoder_set_config,
344 	.destroy = sil164_encoder_destroy,
345 	.dpms = sil164_encoder_dpms,
346 	.save = sil164_encoder_save,
347 	.restore = sil164_encoder_restore,
348 	.mode_fixup = sil164_encoder_mode_fixup,
349 	.mode_valid = sil164_encoder_mode_valid,
350 	.mode_set = sil164_encoder_mode_set,
351 	.detect = sil164_encoder_detect,
352 	.get_modes = sil164_encoder_get_modes,
353 	.create_resources = sil164_encoder_create_resources,
354 	.set_property = sil164_encoder_set_property,
355 };
356 
357 /* I2C driver functions */
358 
359 static int
360 sil164_probe(struct i2c_client *client, const struct i2c_device_id *id)
361 {
362 	int vendor = sil164_read(client, SIL164_VENDOR_HI) << 8 |
363 		sil164_read(client, SIL164_VENDOR_LO);
364 	int device = sil164_read(client, SIL164_DEVICE_HI) << 8 |
365 		sil164_read(client, SIL164_DEVICE_LO);
366 	int rev = sil164_read(client, SIL164_REVISION);
367 
368 	if (vendor != 0x1 || device != 0x6) {
369 		sil164_dbg(client, "Unknown device %x:%x.%x\n",
370 			   vendor, device, rev);
371 		return -ENODEV;
372 	}
373 
374 	sil164_info(client, "Detected device %x:%x.%x\n",
375 		    vendor, device, rev);
376 
377 	return 0;
378 }
379 
380 static int
381 sil164_remove(struct i2c_client *client)
382 {
383 	return 0;
384 }
385 
386 static struct i2c_client *
387 sil164_detect_slave(struct i2c_client *client)
388 {
389 	struct i2c_adapter *adap = client->adapter;
390 	struct i2c_msg msg = {
391 		.addr = SIL164_I2C_ADDR_SLAVE,
392 		.len = 0,
393 	};
394 	const struct i2c_board_info info = {
395 		I2C_BOARD_INFO("sil164", SIL164_I2C_ADDR_SLAVE)
396 	};
397 
398 	if (i2c_transfer(adap, &msg, 1) != 1) {
399 		sil164_dbg(adap, "No dual-link slave found.");
400 		return NULL;
401 	}
402 
403 	return i2c_new_device(adap, &info);
404 }
405 
406 static int
407 sil164_encoder_init(struct i2c_client *client,
408 		    struct drm_device *dev,
409 		    struct drm_encoder_slave *encoder)
410 {
411 	struct sil164_priv *priv;
412 
413 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
414 	if (!priv)
415 		return -ENOMEM;
416 
417 	encoder->slave_priv = priv;
418 	encoder->slave_funcs = &sil164_encoder_funcs;
419 
420 	priv->duallink_slave = sil164_detect_slave(client);
421 
422 	return 0;
423 }
424 
425 static struct i2c_device_id sil164_ids[] = {
426 	{ "sil164", 0 },
427 	{ }
428 };
429 MODULE_DEVICE_TABLE(i2c, sil164_ids);
430 
431 static struct drm_i2c_encoder_driver sil164_driver = {
432 	.i2c_driver = {
433 		.probe = sil164_probe,
434 		.remove = sil164_remove,
435 		.driver = {
436 			.name = "sil164",
437 		},
438 		.id_table = sil164_ids,
439 	},
440 	.encoder_init = sil164_encoder_init,
441 };
442 
443 /* Module initialization */
444 
445 static int __init
446 sil164_init(void)
447 {
448 	return drm_i2c_encoder_register(THIS_MODULE, &sil164_driver);
449 }
450 
451 static void __exit
452 sil164_exit(void)
453 {
454 	drm_i2c_encoder_unregister(&sil164_driver);
455 }
456 
457 MODULE_AUTHOR("Francisco Jerez <currojerez@riseup.net>");
458 MODULE_DESCRIPTION("Silicon Image sil164 TMDS transmitter driver");
459 MODULE_LICENSE("GPL and additional rights");
460 
461 module_init(sil164_init);
462 module_exit(sil164_exit);
463