xref: /openbmc/linux/drivers/gpu/drm/i2c/sil164_drv.c (revision 0352f880)
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 <linux/module.h>
28 
29 #include <drm/drm_drv.h>
30 #include <drm/drm_encoder_slave.h>
31 #include <drm/drm_print.h>
32 #include <drm/drm_probe_helper.h>
33 #include <drm/i2c/sil164.h>
34 
35 struct sil164_priv {
36 	struct sil164_encoder_params config;
37 	struct i2c_client *duallink_slave;
38 
39 	uint8_t saved_state[0x10];
40 	uint8_t saved_slave_state[0x10];
41 };
42 
43 #define to_sil164_priv(x) \
44 	((struct sil164_priv *)to_encoder_slave(x)->slave_priv)
45 
46 #define sil164_dbg(client, format, ...) do {				\
47 		if (drm_debug_enabled(DRM_UT_KMS))			\
48 			dev_printk(KERN_DEBUG, &client->dev,		\
49 				   "%s: " format, __func__, ## __VA_ARGS__); \
50 	} while (0)
51 #define sil164_info(client, format, ...)		\
52 	dev_info(&client->dev, format, __VA_ARGS__)
53 #define sil164_err(client, format, ...)			\
54 	dev_err(&client->dev, format, __VA_ARGS__)
55 
56 #define SIL164_I2C_ADDR_MASTER			0x38
57 #define SIL164_I2C_ADDR_SLAVE			0x39
58 
59 /* HW register definitions */
60 
61 #define SIL164_VENDOR_LO			0x0
62 #define SIL164_VENDOR_HI			0x1
63 #define SIL164_DEVICE_LO			0x2
64 #define SIL164_DEVICE_HI			0x3
65 #define SIL164_REVISION				0x4
66 #define SIL164_FREQ_MIN				0x6
67 #define SIL164_FREQ_MAX				0x7
68 #define SIL164_CONTROL0				0x8
69 #  define SIL164_CONTROL0_POWER_ON		0x01
70 #  define SIL164_CONTROL0_EDGE_RISING		0x02
71 #  define SIL164_CONTROL0_INPUT_24BIT		0x04
72 #  define SIL164_CONTROL0_DUAL_EDGE		0x08
73 #  define SIL164_CONTROL0_HSYNC_ON		0x10
74 #  define SIL164_CONTROL0_VSYNC_ON		0x20
75 #define SIL164_DETECT				0x9
76 #  define SIL164_DETECT_INTR_STAT		0x01
77 #  define SIL164_DETECT_HOTPLUG_STAT		0x02
78 #  define SIL164_DETECT_RECEIVER_STAT		0x04
79 #  define SIL164_DETECT_INTR_MODE_RECEIVER	0x00
80 #  define SIL164_DETECT_INTR_MODE_HOTPLUG	0x08
81 #  define SIL164_DETECT_OUT_MODE_HIGH		0x00
82 #  define SIL164_DETECT_OUT_MODE_INTR		0x10
83 #  define SIL164_DETECT_OUT_MODE_RECEIVER	0x20
84 #  define SIL164_DETECT_OUT_MODE_HOTPLUG	0x30
85 #  define SIL164_DETECT_VSWING_STAT		0x80
86 #define SIL164_CONTROL1				0xa
87 #  define SIL164_CONTROL1_DESKEW_ENABLE		0x10
88 #  define SIL164_CONTROL1_DESKEW_INCR_SHIFT	5
89 #define SIL164_GPIO				0xb
90 #define SIL164_CONTROL2				0xc
91 #  define SIL164_CONTROL2_FILTER_ENABLE		0x01
92 #  define SIL164_CONTROL2_FILTER_SETTING_SHIFT	1
93 #  define SIL164_CONTROL2_DUALLINK_MASTER	0x40
94 #  define SIL164_CONTROL2_SYNC_CONT		0x80
95 #define SIL164_DUALLINK				0xd
96 #  define SIL164_DUALLINK_ENABLE		0x10
97 #  define SIL164_DUALLINK_SKEW_SHIFT		5
98 #define SIL164_PLLZONE				0xe
99 #  define SIL164_PLLZONE_STAT			0x08
100 #  define SIL164_PLLZONE_FORCE_ON		0x10
101 #  define SIL164_PLLZONE_FORCE_HIGH		0x20
102 
103 /* HW access functions */
104 
105 static void
106 sil164_write(struct i2c_client *client, uint8_t addr, uint8_t val)
107 {
108 	uint8_t buf[] = {addr, val};
109 	int ret;
110 
111 	ret = i2c_master_send(client, buf, ARRAY_SIZE(buf));
112 	if (ret < 0)
113 		sil164_err(client, "Error %d writing to subaddress 0x%x\n",
114 			   ret, addr);
115 }
116 
117 static uint8_t
118 sil164_read(struct i2c_client *client, uint8_t addr)
119 {
120 	uint8_t val;
121 	int ret;
122 
123 	ret = i2c_master_send(client, &addr, sizeof(addr));
124 	if (ret < 0)
125 		goto fail;
126 
127 	ret = i2c_master_recv(client, &val, sizeof(val));
128 	if (ret < 0)
129 		goto fail;
130 
131 	return val;
132 
133 fail:
134 	sil164_err(client, "Error %d reading from subaddress 0x%x\n",
135 		   ret, addr);
136 	return 0;
137 }
138 
139 static void
140 sil164_save_state(struct i2c_client *client, uint8_t *state)
141 {
142 	int i;
143 
144 	for (i = 0x8; i <= 0xe; i++)
145 		state[i] = sil164_read(client, i);
146 }
147 
148 static void
149 sil164_restore_state(struct i2c_client *client, uint8_t *state)
150 {
151 	int i;
152 
153 	for (i = 0x8; i <= 0xe; i++)
154 		sil164_write(client, i, state[i]);
155 }
156 
157 static void
158 sil164_set_power_state(struct i2c_client *client, bool on)
159 {
160 	uint8_t control0 = sil164_read(client, SIL164_CONTROL0);
161 
162 	if (on)
163 		control0 |= SIL164_CONTROL0_POWER_ON;
164 	else
165 		control0 &= ~SIL164_CONTROL0_POWER_ON;
166 
167 	sil164_write(client, SIL164_CONTROL0, control0);
168 }
169 
170 static void
171 sil164_init_state(struct i2c_client *client,
172 		  struct sil164_encoder_params *config,
173 		  bool duallink)
174 {
175 	sil164_write(client, SIL164_CONTROL0,
176 		     SIL164_CONTROL0_HSYNC_ON |
177 		     SIL164_CONTROL0_VSYNC_ON |
178 		     (config->input_edge ? SIL164_CONTROL0_EDGE_RISING : 0) |
179 		     (config->input_width ? SIL164_CONTROL0_INPUT_24BIT : 0) |
180 		     (config->input_dual ? SIL164_CONTROL0_DUAL_EDGE : 0));
181 
182 	sil164_write(client, SIL164_DETECT,
183 		     SIL164_DETECT_INTR_STAT |
184 		     SIL164_DETECT_OUT_MODE_RECEIVER);
185 
186 	sil164_write(client, SIL164_CONTROL1,
187 		     (config->input_skew ? SIL164_CONTROL1_DESKEW_ENABLE : 0) |
188 		     (((config->input_skew + 4) & 0x7)
189 		      << SIL164_CONTROL1_DESKEW_INCR_SHIFT));
190 
191 	sil164_write(client, SIL164_CONTROL2,
192 		     SIL164_CONTROL2_SYNC_CONT |
193 		     (config->pll_filter ? 0 : SIL164_CONTROL2_FILTER_ENABLE) |
194 		     (4 << SIL164_CONTROL2_FILTER_SETTING_SHIFT));
195 
196 	sil164_write(client, SIL164_PLLZONE, 0);
197 
198 	if (duallink)
199 		sil164_write(client, SIL164_DUALLINK,
200 			     SIL164_DUALLINK_ENABLE |
201 			     (((config->duallink_skew + 4) & 0x7)
202 			      << SIL164_DUALLINK_SKEW_SHIFT));
203 	else
204 		sil164_write(client, SIL164_DUALLINK, 0);
205 }
206 
207 /* DRM encoder functions */
208 
209 static void
210 sil164_encoder_set_config(struct drm_encoder *encoder, void *params)
211 {
212 	struct sil164_priv *priv = to_sil164_priv(encoder);
213 
214 	priv->config = *(struct sil164_encoder_params *)params;
215 }
216 
217 static void
218 sil164_encoder_dpms(struct drm_encoder *encoder, int mode)
219 {
220 	struct sil164_priv *priv = to_sil164_priv(encoder);
221 	bool on = (mode == DRM_MODE_DPMS_ON);
222 	bool duallink = (on && encoder->crtc->mode.clock > 165000);
223 
224 	sil164_set_power_state(drm_i2c_encoder_get_client(encoder), on);
225 
226 	if (priv->duallink_slave)
227 		sil164_set_power_state(priv->duallink_slave, duallink);
228 }
229 
230 static void
231 sil164_encoder_save(struct drm_encoder *encoder)
232 {
233 	struct sil164_priv *priv = to_sil164_priv(encoder);
234 
235 	sil164_save_state(drm_i2c_encoder_get_client(encoder),
236 			  priv->saved_state);
237 
238 	if (priv->duallink_slave)
239 		sil164_save_state(priv->duallink_slave,
240 				  priv->saved_slave_state);
241 }
242 
243 static void
244 sil164_encoder_restore(struct drm_encoder *encoder)
245 {
246 	struct sil164_priv *priv = to_sil164_priv(encoder);
247 
248 	sil164_restore_state(drm_i2c_encoder_get_client(encoder),
249 			     priv->saved_state);
250 
251 	if (priv->duallink_slave)
252 		sil164_restore_state(priv->duallink_slave,
253 				     priv->saved_slave_state);
254 }
255 
256 static int
257 sil164_encoder_mode_valid(struct drm_encoder *encoder,
258 			  struct drm_display_mode *mode)
259 {
260 	struct sil164_priv *priv = to_sil164_priv(encoder);
261 
262 	if (mode->clock < 32000)
263 		return MODE_CLOCK_LOW;
264 
265 	if (mode->clock > 330000 ||
266 	    (mode->clock > 165000 && !priv->duallink_slave))
267 		return MODE_CLOCK_HIGH;
268 
269 	return MODE_OK;
270 }
271 
272 static void
273 sil164_encoder_mode_set(struct drm_encoder *encoder,
274 			struct drm_display_mode *mode,
275 			struct drm_display_mode *adjusted_mode)
276 {
277 	struct sil164_priv *priv = to_sil164_priv(encoder);
278 	bool duallink = adjusted_mode->clock > 165000;
279 
280 	sil164_init_state(drm_i2c_encoder_get_client(encoder),
281 			  &priv->config, duallink);
282 
283 	if (priv->duallink_slave)
284 		sil164_init_state(priv->duallink_slave,
285 				  &priv->config, duallink);
286 
287 	sil164_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
288 }
289 
290 static enum drm_connector_status
291 sil164_encoder_detect(struct drm_encoder *encoder,
292 		      struct drm_connector *connector)
293 {
294 	struct i2c_client *client = drm_i2c_encoder_get_client(encoder);
295 
296 	if (sil164_read(client, SIL164_DETECT) & SIL164_DETECT_HOTPLUG_STAT)
297 		return connector_status_connected;
298 	else
299 		return connector_status_disconnected;
300 }
301 
302 static int
303 sil164_encoder_get_modes(struct drm_encoder *encoder,
304 			 struct drm_connector *connector)
305 {
306 	return 0;
307 }
308 
309 static int
310 sil164_encoder_create_resources(struct drm_encoder *encoder,
311 				struct drm_connector *connector)
312 {
313 	return 0;
314 }
315 
316 static int
317 sil164_encoder_set_property(struct drm_encoder *encoder,
318 			    struct drm_connector *connector,
319 			    struct drm_property *property,
320 			    uint64_t val)
321 {
322 	return 0;
323 }
324 
325 static void
326 sil164_encoder_destroy(struct drm_encoder *encoder)
327 {
328 	struct sil164_priv *priv = to_sil164_priv(encoder);
329 
330 	i2c_unregister_device(priv->duallink_slave);
331 
332 	kfree(priv);
333 	drm_i2c_encoder_destroy(encoder);
334 }
335 
336 static const struct drm_encoder_slave_funcs sil164_encoder_funcs = {
337 	.set_config = sil164_encoder_set_config,
338 	.destroy = sil164_encoder_destroy,
339 	.dpms = sil164_encoder_dpms,
340 	.save = sil164_encoder_save,
341 	.restore = sil164_encoder_restore,
342 	.mode_valid = sil164_encoder_mode_valid,
343 	.mode_set = sil164_encoder_mode_set,
344 	.detect = sil164_encoder_detect,
345 	.get_modes = sil164_encoder_get_modes,
346 	.create_resources = sil164_encoder_create_resources,
347 	.set_property = sil164_encoder_set_property,
348 };
349 
350 /* I2C driver functions */
351 
352 static int
353 sil164_probe(struct i2c_client *client, const struct i2c_device_id *id)
354 {
355 	int vendor = sil164_read(client, SIL164_VENDOR_HI) << 8 |
356 		sil164_read(client, SIL164_VENDOR_LO);
357 	int device = sil164_read(client, SIL164_DEVICE_HI) << 8 |
358 		sil164_read(client, SIL164_DEVICE_LO);
359 	int rev = sil164_read(client, SIL164_REVISION);
360 
361 	if (vendor != 0x1 || device != 0x6) {
362 		sil164_dbg(client, "Unknown device %x:%x.%x\n",
363 			   vendor, device, rev);
364 		return -ENODEV;
365 	}
366 
367 	sil164_info(client, "Detected device %x:%x.%x\n",
368 		    vendor, device, rev);
369 
370 	return 0;
371 }
372 
373 static struct i2c_client *
374 sil164_detect_slave(struct i2c_client *client)
375 {
376 	struct i2c_adapter *adap = client->adapter;
377 	struct i2c_msg msg = {
378 		.addr = SIL164_I2C_ADDR_SLAVE,
379 		.len = 0,
380 	};
381 	const struct i2c_board_info info = {
382 		I2C_BOARD_INFO("sil164", SIL164_I2C_ADDR_SLAVE)
383 	};
384 
385 	if (i2c_transfer(adap, &msg, 1) != 1) {
386 		sil164_dbg(adap, "No dual-link slave found.");
387 		return NULL;
388 	}
389 
390 	return i2c_new_client_device(adap, &info);
391 }
392 
393 static int
394 sil164_encoder_init(struct i2c_client *client,
395 		    struct drm_device *dev,
396 		    struct drm_encoder_slave *encoder)
397 {
398 	struct sil164_priv *priv;
399 	struct i2c_client *slave_client;
400 
401 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
402 	if (!priv)
403 		return -ENOMEM;
404 
405 	encoder->slave_priv = priv;
406 	encoder->slave_funcs = &sil164_encoder_funcs;
407 
408 	slave_client = sil164_detect_slave(client);
409 	if (!IS_ERR(slave_client))
410 		priv->duallink_slave = slave_client;
411 
412 	return 0;
413 }
414 
415 static const struct i2c_device_id sil164_ids[] = {
416 	{ "sil164", 0 },
417 	{ }
418 };
419 MODULE_DEVICE_TABLE(i2c, sil164_ids);
420 
421 static struct drm_i2c_encoder_driver sil164_driver = {
422 	.i2c_driver = {
423 		.probe = sil164_probe,
424 		.driver = {
425 			.name = "sil164",
426 		},
427 		.id_table = sil164_ids,
428 	},
429 	.encoder_init = sil164_encoder_init,
430 };
431 
432 /* Module initialization */
433 
434 static int __init
435 sil164_init(void)
436 {
437 	return drm_i2c_encoder_register(THIS_MODULE, &sil164_driver);
438 }
439 
440 static void __exit
441 sil164_exit(void)
442 {
443 	drm_i2c_encoder_unregister(&sil164_driver);
444 }
445 
446 MODULE_AUTHOR("Francisco Jerez <currojerez@riseup.net>");
447 MODULE_DESCRIPTION("Silicon Image sil164 TMDS transmitter driver");
448 MODULE_LICENSE("GPL and additional rights");
449 
450 module_init(sil164_init);
451 module_exit(sil164_exit);
452