1/*	$NetBSD: sil164_drv.c,v 1.3 2021/12/18 23:45:27 riastradh Exp $	*/
2
3/*
4 * Copyright (C) 2010 Francisco Jerez.
5 * All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining
8 * a copy of this software and associated documentation files (the
9 * "Software"), to deal in the Software without restriction, including
10 * without limitation the rights to use, copy, modify, merge, publish,
11 * distribute, sublicense, and/or sell copies of the Software, and to
12 * permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
14 *
15 * The above copyright notice and this permission notice (including the
16 * next paragraph) shall be included in all copies or substantial
17 * portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
22 * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
23 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
24 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
25 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26 *
27 */
28
29#include <sys/cdefs.h>
30__KERNEL_RCSID(0, "$NetBSD: sil164_drv.c,v 1.3 2021/12/18 23:45:27 riastradh Exp $");
31
32#include <linux/module.h>
33
34#include <drm/drm_drv.h>
35#include <drm/drm_encoder_slave.h>
36#include <drm/drm_print.h>
37#include <drm/drm_probe_helper.h>
38#include <drm/i2c/sil164.h>
39
40struct sil164_priv {
41	struct sil164_encoder_params config;
42	struct i2c_client *duallink_slave;
43
44	uint8_t saved_state[0x10];
45	uint8_t saved_slave_state[0x10];
46};
47
48#define to_sil164_priv(x) \
49	((struct sil164_priv *)to_encoder_slave(x)->slave_priv)
50
51#define sil164_dbg(client, format, ...) do {				\
52		if (drm_debug_enabled(DRM_UT_KMS))			\
53			dev_printk(KERN_DEBUG, &client->dev,		\
54				   "%s: " format, __func__, ## __VA_ARGS__); \
55	} while (0)
56#define sil164_info(client, format, ...)		\
57	dev_info(&client->dev, format, __VA_ARGS__)
58#define sil164_err(client, format, ...)			\
59	dev_err(&client->dev, format, __VA_ARGS__)
60
61#define SIL164_I2C_ADDR_MASTER			0x38
62#define SIL164_I2C_ADDR_SLAVE			0x39
63
64/* HW register definitions */
65
66#define SIL164_VENDOR_LO			0x0
67#define SIL164_VENDOR_HI			0x1
68#define SIL164_DEVICE_LO			0x2
69#define SIL164_DEVICE_HI			0x3
70#define SIL164_REVISION				0x4
71#define SIL164_FREQ_MIN				0x6
72#define SIL164_FREQ_MAX				0x7
73#define SIL164_CONTROL0				0x8
74#  define SIL164_CONTROL0_POWER_ON		0x01
75#  define SIL164_CONTROL0_EDGE_RISING		0x02
76#  define SIL164_CONTROL0_INPUT_24BIT		0x04
77#  define SIL164_CONTROL0_DUAL_EDGE		0x08
78#  define SIL164_CONTROL0_HSYNC_ON		0x10
79#  define SIL164_CONTROL0_VSYNC_ON		0x20
80#define SIL164_DETECT				0x9
81#  define SIL164_DETECT_INTR_STAT		0x01
82#  define SIL164_DETECT_HOTPLUG_STAT		0x02
83#  define SIL164_DETECT_RECEIVER_STAT		0x04
84#  define SIL164_DETECT_INTR_MODE_RECEIVER	0x00
85#  define SIL164_DETECT_INTR_MODE_HOTPLUG	0x08
86#  define SIL164_DETECT_OUT_MODE_HIGH		0x00
87#  define SIL164_DETECT_OUT_MODE_INTR		0x10
88#  define SIL164_DETECT_OUT_MODE_RECEIVER	0x20
89#  define SIL164_DETECT_OUT_MODE_HOTPLUG	0x30
90#  define SIL164_DETECT_VSWING_STAT		0x80
91#define SIL164_CONTROL1				0xa
92#  define SIL164_CONTROL1_DESKEW_ENABLE		0x10
93#  define SIL164_CONTROL1_DESKEW_INCR_SHIFT	5
94#define SIL164_GPIO				0xb
95#define SIL164_CONTROL2				0xc
96#  define SIL164_CONTROL2_FILTER_ENABLE		0x01
97#  define SIL164_CONTROL2_FILTER_SETTING_SHIFT	1
98#  define SIL164_CONTROL2_DUALLINK_MASTER	0x40
99#  define SIL164_CONTROL2_SYNC_CONT		0x80
100#define SIL164_DUALLINK				0xd
101#  define SIL164_DUALLINK_ENABLE		0x10
102#  define SIL164_DUALLINK_SKEW_SHIFT		5
103#define SIL164_PLLZONE				0xe
104#  define SIL164_PLLZONE_STAT			0x08
105#  define SIL164_PLLZONE_FORCE_ON		0x10
106#  define SIL164_PLLZONE_FORCE_HIGH		0x20
107
108/* HW access functions */
109
110static void
111sil164_write(struct i2c_client *client, uint8_t addr, uint8_t val)
112{
113	uint8_t buf[] = {addr, val};
114	int ret;
115
116	ret = i2c_master_send(client, buf, ARRAY_SIZE(buf));
117	if (ret < 0)
118		sil164_err(client, "Error %d writing to subaddress 0x%x\n",
119			   ret, addr);
120}
121
122static uint8_t
123sil164_read(struct i2c_client *client, uint8_t addr)
124{
125	uint8_t val;
126	int ret;
127
128	ret = i2c_master_send(client, &addr, sizeof(addr));
129	if (ret < 0)
130		goto fail;
131
132	ret = i2c_master_recv(client, &val, sizeof(val));
133	if (ret < 0)
134		goto fail;
135
136	return val;
137
138fail:
139	sil164_err(client, "Error %d reading from subaddress 0x%x\n",
140		   ret, addr);
141	return 0;
142}
143
144static void
145sil164_save_state(struct i2c_client *client, uint8_t *state)
146{
147	int i;
148
149	for (i = 0x8; i <= 0xe; i++)
150		state[i] = sil164_read(client, i);
151}
152
153static void
154sil164_restore_state(struct i2c_client *client, uint8_t *state)
155{
156	int i;
157
158	for (i = 0x8; i <= 0xe; i++)
159		sil164_write(client, i, state[i]);
160}
161
162static void
163sil164_set_power_state(struct i2c_client *client, bool on)
164{
165	uint8_t control0 = sil164_read(client, SIL164_CONTROL0);
166
167	if (on)
168		control0 |= SIL164_CONTROL0_POWER_ON;
169	else
170		control0 &= ~SIL164_CONTROL0_POWER_ON;
171
172	sil164_write(client, SIL164_CONTROL0, control0);
173}
174
175static void
176sil164_init_state(struct i2c_client *client,
177		  struct sil164_encoder_params *config,
178		  bool duallink)
179{
180	sil164_write(client, SIL164_CONTROL0,
181		     SIL164_CONTROL0_HSYNC_ON |
182		     SIL164_CONTROL0_VSYNC_ON |
183		     (config->input_edge ? SIL164_CONTROL0_EDGE_RISING : 0) |
184		     (config->input_width ? SIL164_CONTROL0_INPUT_24BIT : 0) |
185		     (config->input_dual ? SIL164_CONTROL0_DUAL_EDGE : 0));
186
187	sil164_write(client, SIL164_DETECT,
188		     SIL164_DETECT_INTR_STAT |
189		     SIL164_DETECT_OUT_MODE_RECEIVER);
190
191	sil164_write(client, SIL164_CONTROL1,
192		     (config->input_skew ? SIL164_CONTROL1_DESKEW_ENABLE : 0) |
193		     (((config->input_skew + 4) & 0x7)
194		      << SIL164_CONTROL1_DESKEW_INCR_SHIFT));
195
196	sil164_write(client, SIL164_CONTROL2,
197		     SIL164_CONTROL2_SYNC_CONT |
198		     (config->pll_filter ? 0 : SIL164_CONTROL2_FILTER_ENABLE) |
199		     (4 << SIL164_CONTROL2_FILTER_SETTING_SHIFT));
200
201	sil164_write(client, SIL164_PLLZONE, 0);
202
203	if (duallink)
204		sil164_write(client, SIL164_DUALLINK,
205			     SIL164_DUALLINK_ENABLE |
206			     (((config->duallink_skew + 4) & 0x7)
207			      << SIL164_DUALLINK_SKEW_SHIFT));
208	else
209		sil164_write(client, SIL164_DUALLINK, 0);
210}
211
212/* DRM encoder functions */
213
214static void
215sil164_encoder_set_config(struct drm_encoder *encoder, void *params)
216{
217	struct sil164_priv *priv = to_sil164_priv(encoder);
218
219	priv->config = *(struct sil164_encoder_params *)params;
220}
221
222static void
223sil164_encoder_dpms(struct drm_encoder *encoder, int mode)
224{
225	struct sil164_priv *priv = to_sil164_priv(encoder);
226	bool on = (mode == DRM_MODE_DPMS_ON);
227	bool duallink = (on && encoder->crtc->mode.clock > 165000);
228
229	sil164_set_power_state(drm_i2c_encoder_get_client(encoder), on);
230
231	if (priv->duallink_slave)
232		sil164_set_power_state(priv->duallink_slave, duallink);
233}
234
235static void
236sil164_encoder_save(struct drm_encoder *encoder)
237{
238	struct sil164_priv *priv = to_sil164_priv(encoder);
239
240	sil164_save_state(drm_i2c_encoder_get_client(encoder),
241			  priv->saved_state);
242
243	if (priv->duallink_slave)
244		sil164_save_state(priv->duallink_slave,
245				  priv->saved_slave_state);
246}
247
248static void
249sil164_encoder_restore(struct drm_encoder *encoder)
250{
251	struct sil164_priv *priv = to_sil164_priv(encoder);
252
253	sil164_restore_state(drm_i2c_encoder_get_client(encoder),
254			     priv->saved_state);
255
256	if (priv->duallink_slave)
257		sil164_restore_state(priv->duallink_slave,
258				     priv->saved_slave_state);
259}
260
261static int
262sil164_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
277static void
278sil164_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
295static enum drm_connector_status
296sil164_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
307static int
308sil164_encoder_get_modes(struct drm_encoder *encoder,
309			 struct drm_connector *connector)
310{
311	return 0;
312}
313
314static int
315sil164_encoder_create_resources(struct drm_encoder *encoder,
316				struct drm_connector *connector)
317{
318	return 0;
319}
320
321static int
322sil164_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
330static void
331sil164_encoder_destroy(struct drm_encoder *encoder)
332{
333	struct sil164_priv *priv = to_sil164_priv(encoder);
334
335	i2c_unregister_device(priv->duallink_slave);
336
337	kfree(priv);
338	drm_i2c_encoder_destroy(encoder);
339}
340
341static const struct drm_encoder_slave_funcs sil164_encoder_funcs = {
342	.set_config = sil164_encoder_set_config,
343	.destroy = sil164_encoder_destroy,
344	.dpms = sil164_encoder_dpms,
345	.save = sil164_encoder_save,
346	.restore = sil164_encoder_restore,
347	.mode_valid = sil164_encoder_mode_valid,
348	.mode_set = sil164_encoder_mode_set,
349	.detect = sil164_encoder_detect,
350	.get_modes = sil164_encoder_get_modes,
351	.create_resources = sil164_encoder_create_resources,
352	.set_property = sil164_encoder_set_property,
353};
354
355/* I2C driver functions */
356
357static int
358sil164_probe(struct i2c_client *client, const struct i2c_device_id *id)
359{
360	int vendor = sil164_read(client, SIL164_VENDOR_HI) << 8 |
361		sil164_read(client, SIL164_VENDOR_LO);
362	int device = sil164_read(client, SIL164_DEVICE_HI) << 8 |
363		sil164_read(client, SIL164_DEVICE_LO);
364	int rev = sil164_read(client, SIL164_REVISION);
365
366	if (vendor != 0x1 || device != 0x6) {
367		sil164_dbg(client, "Unknown device %x:%x.%x\n",
368			   vendor, device, rev);
369		return -ENODEV;
370	}
371
372	sil164_info(client, "Detected device %x:%x.%x\n",
373		    vendor, device, rev);
374
375	return 0;
376}
377
378static int
379sil164_remove(struct i2c_client *client)
380{
381	return 0;
382}
383
384static struct i2c_client *
385sil164_detect_slave(struct i2c_client *client)
386{
387	struct i2c_adapter *adap = client->adapter;
388	struct i2c_msg msg = {
389		.addr = SIL164_I2C_ADDR_SLAVE,
390		.len = 0,
391	};
392	const struct i2c_board_info info = {
393		I2C_BOARD_INFO("sil164", SIL164_I2C_ADDR_SLAVE)
394	};
395
396	if (i2c_transfer(adap, &msg, 1) != 1) {
397		sil164_dbg(adap, "No dual-link slave found.");
398		return NULL;
399	}
400
401	return i2c_new_device(adap, &info);
402}
403
404static int
405sil164_encoder_init(struct i2c_client *client,
406		    struct drm_device *dev,
407		    struct drm_encoder_slave *encoder)
408{
409	struct sil164_priv *priv;
410
411	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
412	if (!priv)
413		return -ENOMEM;
414
415	encoder->slave_priv = priv;
416	encoder->slave_funcs = &sil164_encoder_funcs;
417
418	priv->duallink_slave = sil164_detect_slave(client);
419
420	return 0;
421}
422
423static const struct i2c_device_id sil164_ids[] = {
424	{ "sil164", 0 },
425	{ }
426};
427MODULE_DEVICE_TABLE(i2c, sil164_ids);
428
429static struct drm_i2c_encoder_driver sil164_driver = {
430	.i2c_driver = {
431		.probe = sil164_probe,
432		.remove = sil164_remove,
433		.driver = {
434			.name = "sil164",
435		},
436		.id_table = sil164_ids,
437	},
438	.encoder_init = sil164_encoder_init,
439};
440
441/* Module initialization */
442
443static int __init
444sil164_init(void)
445{
446	return drm_i2c_encoder_register(THIS_MODULE, &sil164_driver);
447}
448
449static void __exit
450sil164_exit(void)
451{
452	drm_i2c_encoder_unregister(&sil164_driver);
453}
454
455MODULE_AUTHOR("Francisco Jerez <currojerez@riseup.net>");
456MODULE_DESCRIPTION("Silicon Image sil164 TMDS transmitter driver");
457MODULE_LICENSE("GPL and additional rights");
458
459module_init(sil164_init);
460module_exit(sil164_exit);
461