1 /*
2  * Copyright 2015 Red Hat Inc.
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 shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: Dave Airlie
23  */
24 #include <drm/drmP.h>
25 #include <drm/radeon_drm.h>
26 #include "radeon.h"
27 #include "nid.h"
28 
29 #define AUX_RX_ERROR_FLAGS (AUX_SW_RX_OVERFLOW |	     \
30 			    AUX_SW_RX_HPD_DISCON |	     \
31 			    AUX_SW_RX_PARTIAL_BYTE |	     \
32 			    AUX_SW_NON_AUX_MODE |	     \
33 			    AUX_SW_RX_MIN_COUNT_VIOL |	     \
34 			    AUX_SW_RX_INVALID_STOP |	     \
35 			    AUX_SW_RX_SYNC_INVALID_L |	     \
36 			    AUX_SW_RX_SYNC_INVALID_H |	     \
37 			    AUX_SW_RX_INVALID_START |	     \
38 			    AUX_SW_RX_RECV_NO_DET |	     \
39 			    AUX_SW_RX_RECV_INVALID_H |	     \
40 			    AUX_SW_RX_RECV_INVALID_V)
41 
42 #define AUX_SW_REPLY_GET_BYTE_COUNT(x) (((x) >> 24) & 0x1f)
43 
44 #define BARE_ADDRESS_SIZE 3
45 
46 static const u32 aux_offset[] =
47 {
48 	0x6200 - 0x6200,
49 	0x6250 - 0x6200,
50 	0x62a0 - 0x6200,
51 	0x6300 - 0x6200,
52 	0x6350 - 0x6200,
53 	0x63a0 - 0x6200,
54 };
55 
56 ssize_t
57 radeon_dp_aux_transfer_native(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
58 {
59 	struct radeon_i2c_chan *chan =
60 		container_of(aux, struct radeon_i2c_chan, aux);
61 	struct drm_device *dev = chan->dev;
62 	struct radeon_device *rdev = dev->dev_private;
63 	int ret = 0, i;
64 	uint32_t tmp, ack = 0;
65 	int instance = chan->rec.i2c_id & 0xf;
66 	u8 byte;
67 	u8 *buf = msg->buffer;
68 	int retry_count = 0;
69 	int bytes;
70 	int msize;
71 	bool is_write = false;
72 
73 	if (WARN_ON(msg->size > 16))
74 		return -E2BIG;
75 
76 	switch (msg->request & ~DP_AUX_I2C_MOT) {
77 	case DP_AUX_NATIVE_WRITE:
78 	case DP_AUX_I2C_WRITE:
79 		is_write = true;
80 		break;
81 	case DP_AUX_NATIVE_READ:
82 	case DP_AUX_I2C_READ:
83 		break;
84 	default:
85 		return -EINVAL;
86 	}
87 
88 	/* work out two sizes required */
89 	msize = 0;
90 	bytes = BARE_ADDRESS_SIZE;
91 	if (msg->size) {
92 		msize = msg->size - 1;
93 		bytes++;
94 		if (is_write)
95 			bytes += msg->size;
96 	}
97 
98 	mutex_lock(&chan->mutex);
99 
100 	/* switch the pad to aux mode */
101 	tmp = RREG32(chan->rec.mask_clk_reg);
102 	tmp |= (1 << 16);
103 	WREG32(chan->rec.mask_clk_reg, tmp);
104 
105 	/* setup AUX control register with correct HPD pin */
106 	tmp = RREG32(AUX_CONTROL + aux_offset[instance]);
107 
108 	tmp &= AUX_HPD_SEL(0x7);
109 	tmp |= AUX_HPD_SEL(chan->rec.hpd);
110 	tmp |= AUX_EN | AUX_LS_READ_EN;
111 
112 	WREG32(AUX_CONTROL + aux_offset[instance], tmp);
113 
114 	/* atombios appears to write this twice lets copy it */
115 	WREG32(AUX_SW_CONTROL + aux_offset[instance],
116 	       AUX_SW_WR_BYTES(bytes));
117 	WREG32(AUX_SW_CONTROL + aux_offset[instance],
118 	       AUX_SW_WR_BYTES(bytes));
119 
120 	/* write the data header into the registers */
121 	/* request, addres, msg size */
122 	byte = (msg->request << 4);
123 	WREG32(AUX_SW_DATA + aux_offset[instance],
124 	       AUX_SW_DATA_MASK(byte) | AUX_SW_AUTOINCREMENT_DISABLE);
125 
126 	byte = (msg->address >> 8) & 0xff;
127 	WREG32(AUX_SW_DATA + aux_offset[instance],
128 	       AUX_SW_DATA_MASK(byte));
129 
130 	byte = msg->address & 0xff;
131 	WREG32(AUX_SW_DATA + aux_offset[instance],
132 	       AUX_SW_DATA_MASK(byte));
133 
134 	byte = msize;
135 	WREG32(AUX_SW_DATA + aux_offset[instance],
136 	       AUX_SW_DATA_MASK(byte));
137 
138 	/* if we are writing - write the msg buffer */
139 	if (is_write) {
140 		for (i = 0; i < msg->size; i++) {
141 			WREG32(AUX_SW_DATA + aux_offset[instance],
142 			       AUX_SW_DATA_MASK(buf[i]));
143 		}
144 	}
145 
146 	/* clear the ACK */
147 	WREG32(AUX_SW_INTERRUPT_CONTROL + aux_offset[instance], AUX_SW_DONE_ACK);
148 
149 	/* write the size and GO bits */
150 	WREG32(AUX_SW_CONTROL + aux_offset[instance],
151 	       AUX_SW_WR_BYTES(bytes) | AUX_SW_GO);
152 
153 	/* poll the status registers - TODO irq support */
154 	do {
155 		tmp = RREG32(AUX_SW_STATUS + aux_offset[instance]);
156 		if (tmp & AUX_SW_DONE) {
157 			break;
158 		}
159 		usleep_range(100, 200);
160 	} while (retry_count++ < 1000);
161 
162 	if (retry_count >= 1000) {
163 		DRM_ERROR("auxch hw never signalled completion, error %08x\n", tmp);
164 		ret = -EIO;
165 		goto done;
166 	}
167 
168 	if (tmp & AUX_SW_RX_TIMEOUT) {
169 		DRM_DEBUG_KMS("dp_aux_ch timed out\n");
170 		ret = -ETIMEDOUT;
171 		goto done;
172 	}
173 	if (tmp & AUX_RX_ERROR_FLAGS) {
174 		DRM_DEBUG_KMS("dp_aux_ch flags not zero: %08x\n", tmp);
175 		ret = -EIO;
176 		goto done;
177 	}
178 
179 	bytes = AUX_SW_REPLY_GET_BYTE_COUNT(tmp);
180 	if (bytes) {
181 		WREG32(AUX_SW_DATA + aux_offset[instance],
182 		       AUX_SW_DATA_RW | AUX_SW_AUTOINCREMENT_DISABLE);
183 
184 		tmp = RREG32(AUX_SW_DATA + aux_offset[instance]);
185 		ack = (tmp >> 8) & 0xff;
186 
187 		for (i = 0; i < bytes - 1; i++) {
188 			tmp = RREG32(AUX_SW_DATA + aux_offset[instance]);
189 			if (buf)
190 				buf[i] = (tmp >> 8) & 0xff;
191 		}
192 		if (buf)
193 			ret = bytes - 1;
194 	}
195 
196 	WREG32(AUX_SW_INTERRUPT_CONTROL + aux_offset[instance], AUX_SW_DONE_ACK);
197 
198 	if (is_write)
199 		ret = msg->size;
200 done:
201 	mutex_unlock(&chan->mutex);
202 
203 	if (ret >= 0)
204 		msg->reply = ack >> 4;
205 	return ret;
206 }
207