1/*
  2 * Copyright © 2016 Intel Corporation
  3 *
  4 * Permission is hereby granted, free of charge, to any person obtaining a
  5 * copy of this software and associated documentation files (the "Software"),
  6 * to deal in the Software without restriction, including without limitation
  7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  8 * and/or sell copies of the Software, and to permit persons to whom the
  9 * Software is furnished to do so, subject to the following conditions:
 10 *
 11 * The above copyright notice and this permission notice (including the next
 12 * paragraph) shall be included in all copies or substantial portions of the
 13 * Software.
 14 *
 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 21 * DEALINGS IN THE SOFTWARE.
 22 *
 23 *
 24 */
 25#include <drm/drm_edid.h>
 26#include <drm/drm_atomic_helper.h>
 27#include <drm/drm_dp_dual_mode_helper.h>
 28#include "intel_drv.h"
 29
 30static struct intel_dp *lspcon_to_intel_dp(struct intel_lspcon *lspcon)
 31{
 32	struct intel_digital_port *dig_port =
 33		container_of(lspcon, struct intel_digital_port, lspcon);
 34
 35	return &dig_port->dp;
 36}
 37
 38static const char *lspcon_mode_name(enum drm_lspcon_mode mode)
 39{
 40	switch (mode) {
 41	case DRM_LSPCON_MODE_PCON:
 42		return "PCON";
 43	case DRM_LSPCON_MODE_LS:
 44		return "LS";
 45	case DRM_LSPCON_MODE_INVALID:
 46		return "INVALID";
 47	default:
 48		MISSING_CASE(mode);
 49		return "INVALID";
 50	}
 51}
 52
 53static enum drm_lspcon_mode lspcon_get_current_mode(struct intel_lspcon *lspcon)
 54{
 55	enum drm_lspcon_mode current_mode;
 56	struct i2c_adapter *adapter = &lspcon_to_intel_dp(lspcon)->aux.ddc;
 57
 58	if (drm_lspcon_get_mode(adapter, &current_mode)) {
 59		DRM_DEBUG_KMS("Error reading LSPCON mode\n");
 60		return DRM_LSPCON_MODE_INVALID;
 61	}
 62	return current_mode;
 63}
 64
 65static enum drm_lspcon_mode lspcon_wait_mode(struct intel_lspcon *lspcon,
 66					     enum drm_lspcon_mode mode)
 67{
 68	enum drm_lspcon_mode current_mode;
 69
 70	current_mode = lspcon_get_current_mode(lspcon);
 71	if (current_mode == mode)
 72		goto out;
 73
 74	DRM_DEBUG_KMS("Waiting for LSPCON mode %s to settle\n",
 75		      lspcon_mode_name(mode));
 76
 77	wait_for((current_mode = lspcon_get_current_mode(lspcon)) == mode, 100);
 78	if (current_mode != mode)
 79		DRM_ERROR("LSPCON mode hasn't settled\n");
 80
 81out:
 82	DRM_DEBUG_KMS("Current LSPCON mode %s\n",
 83		      lspcon_mode_name(current_mode));
 84
 85	return current_mode;
 86}
 87
 88static int lspcon_change_mode(struct intel_lspcon *lspcon,
 89			      enum drm_lspcon_mode mode)
 90{
 91	int err;
 92	enum drm_lspcon_mode current_mode;
 93	struct i2c_adapter *adapter = &lspcon_to_intel_dp(lspcon)->aux.ddc;
 94
 95	err = drm_lspcon_get_mode(adapter, &current_mode);
 96	if (err) {
 97		DRM_ERROR("Error reading LSPCON mode\n");
 98		return err;
 99	}
100
101	if (current_mode == mode) {
102		DRM_DEBUG_KMS("Current mode = desired LSPCON mode\n");
103		return 0;
104	}
105
106	err = drm_lspcon_set_mode(adapter, mode);
107	if (err < 0) {
108		DRM_ERROR("LSPCON mode change failed\n");
109		return err;
110	}
111
112	lspcon->mode = mode;
113	DRM_DEBUG_KMS("LSPCON mode changed done\n");
114	return 0;
115}
116
117static bool lspcon_wake_native_aux_ch(struct intel_lspcon *lspcon)
118{
119	uint8_t rev;
120
121	if (drm_dp_dpcd_readb(&lspcon_to_intel_dp(lspcon)->aux, DP_DPCD_REV,
122			      &rev) != 1) {
123		DRM_DEBUG_KMS("Native AUX CH down\n");
124		return false;
125	}
126
127	DRM_DEBUG_KMS("Native AUX CH up, DPCD version: %d.%d\n",
128		      rev >> 4, rev & 0xf);
129
130	return true;
131}
132
133static bool lspcon_probe(struct intel_lspcon *lspcon)
134{
135	int retry;
136	enum drm_dp_dual_mode_type adaptor_type;
137	struct i2c_adapter *adapter = &lspcon_to_intel_dp(lspcon)->aux.ddc;
138	enum drm_lspcon_mode expected_mode;
139
140	expected_mode = lspcon_wake_native_aux_ch(lspcon) ?
141			DRM_LSPCON_MODE_PCON : DRM_LSPCON_MODE_LS;
142
143	/* Lets probe the adaptor and check its type */
144	for (retry = 0; retry < 6; retry++) {
145		if (retry)
146			usleep_range(500, 1000);
147
148		adaptor_type = drm_dp_dual_mode_detect(adapter);
149		if (adaptor_type == DRM_DP_DUAL_MODE_LSPCON)
150			break;
151	}
152
153	if (adaptor_type != DRM_DP_DUAL_MODE_LSPCON) {
154		DRM_DEBUG_KMS("No LSPCON detected, found %s\n",
155			       drm_dp_get_dual_mode_type_name(adaptor_type));
156		return false;
157	}
158
159	/* Yay ... got a LSPCON device */
160	DRM_DEBUG_KMS("LSPCON detected\n");
161	lspcon->mode = lspcon_wait_mode(lspcon, expected_mode);
162	lspcon->active = true;
163	return true;
164}
165
166static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon)
167{
168	struct intel_dp *intel_dp = lspcon_to_intel_dp(lspcon);
169	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
170	unsigned long start = jiffies;
171
172	while (1) {
173		if (intel_digital_port_connected(&dig_port->base)) {
174			DRM_DEBUG_KMS("LSPCON recovering in PCON mode after %u ms\n",
175				      jiffies_to_msecs(jiffies - start));
176			return;
177		}
178
179		if (time_after(jiffies, start + msecs_to_jiffies(1000)))
180			break;
181
182		usleep_range(10000, 15000);
183	}
184
185	DRM_DEBUG_KMS("LSPCON DP descriptor mismatch after resume\n");
186}
187
188void lspcon_resume(struct intel_lspcon *lspcon)
189{
190	enum drm_lspcon_mode expected_mode;
191
192	if (lspcon_wake_native_aux_ch(lspcon)) {
193		expected_mode = DRM_LSPCON_MODE_PCON;
194		lspcon_resume_in_pcon_wa(lspcon);
195	} else {
196		expected_mode = DRM_LSPCON_MODE_LS;
197	}
198
199	if (lspcon_wait_mode(lspcon, expected_mode) == DRM_LSPCON_MODE_PCON)
200		return;
201
202	if (lspcon_change_mode(lspcon, DRM_LSPCON_MODE_PCON))
203		DRM_ERROR("LSPCON resume failed\n");
204	else
205		DRM_DEBUG_KMS("LSPCON resume success\n");
206}
207
208void lspcon_wait_pcon_mode(struct intel_lspcon *lspcon)
209{
210	lspcon_wait_mode(lspcon, DRM_LSPCON_MODE_PCON);
211}
212
213bool lspcon_init(struct intel_digital_port *intel_dig_port)
214{
215	struct intel_dp *dp = &intel_dig_port->dp;
216	struct intel_lspcon *lspcon = &intel_dig_port->lspcon;
217	struct drm_device *dev = intel_dig_port->base.base.dev;
218	struct drm_i915_private *dev_priv = to_i915(dev);
219
220	if (!HAS_LSPCON(dev_priv)) {
221		DRM_ERROR("LSPCON is not supported on this platform\n");
222		return false;
223	}
224
225	lspcon->active = false;
226	lspcon->mode = DRM_LSPCON_MODE_INVALID;
227
228	if (!lspcon_probe(lspcon)) {
229		DRM_ERROR("Failed to probe lspcon\n");
230		return false;
231	}
232
233	/*
234	* In the SW state machine, lets Put LSPCON in PCON mode only.
235	* In this way, it will work with both HDMI 1.4 sinks as well as HDMI
236	* 2.0 sinks.
237	*/
238	if (lspcon->active && lspcon->mode != DRM_LSPCON_MODE_PCON) {
239		if (lspcon_change_mode(lspcon, DRM_LSPCON_MODE_PCON) < 0) {
240			DRM_ERROR("LSPCON mode change to PCON failed\n");
241			return false;
242		}
243	}
244
245	if (!intel_dp_read_dpcd(dp)) {
246		DRM_ERROR("LSPCON DPCD read failed\n");
247		return false;
248	}
249
250	drm_dp_read_desc(&dp->aux, &dp->desc, drm_dp_is_branch(dp->dpcd));
251
252	DRM_DEBUG_KMS("Success: LSPCON init\n");
253	return true;
254}