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_SYNC_INVALID_L |	     \
34 			    AUX_SW_RX_SYNC_INVALID_H |	     \
35 			    AUX_SW_RX_INVALID_START |	     \
36 			    AUX_SW_RX_RECV_NO_DET |	     \
37 			    AUX_SW_RX_RECV_INVALID_H |	     \
38 			    AUX_SW_RX_RECV_INVALID_V)
39 
40 #define AUX_SW_REPLY_GET_BYTE_COUNT(x) (((x) >> 24) & 0x1f)
41 
42 #define BARE_ADDRESS_SIZE 3
43 
44 static const u32 aux_offset[] =
45 {
46 	0x6200 - 0x6200,
47 	0x6250 - 0x6200,
48 	0x62a0 - 0x6200,
49 	0x6300 - 0x6200,
50 	0x6350 - 0x6200,
51 	0x63a0 - 0x6200,
52 };
53 
54 ssize_t
55 radeon_dp_aux_transfer_native(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
56 {
57 	struct radeon_i2c_chan *chan =
58 		container_of(aux, struct radeon_i2c_chan, aux);
59 	struct drm_device *dev = chan->dev;
60 	struct radeon_device *rdev = dev->dev_private;
61 	int ret = 0, i;
62 	uint32_t tmp, ack = 0;
63 	int instance = chan->rec.i2c_id & 0xf;
64 	u8 byte;
65 	u8 *buf = msg->buffer;
66 	int retry_count = 0;
67 	int bytes;
68 	int msize;
69 	bool is_write = false;
70 
71 	if (WARN_ON(msg->size > 16))
72 		return -E2BIG;
73 
74 	switch (msg->request & ~DP_AUX_I2C_MOT) {
75 	case DP_AUX_NATIVE_WRITE:
76 	case DP_AUX_I2C_WRITE:
77 		is_write = true;
78 		break;
79 	case DP_AUX_NATIVE_READ:
80 	case DP_AUX_I2C_READ:
81 		break;
82 	default:
83 		return -EINVAL;
84 	}
85 
86 	/* work out two sizes required */
87 	msize = 0;
88 	bytes = BARE_ADDRESS_SIZE;
89 	if (msg->size) {
90 		msize = msg->size - 1;
91 		bytes++;
92 		if (is_write)
93 			bytes += msg->size;
94 	}
95 
96 	mutex_lock(&chan->mutex);
97 
98 	/* switch the pad to aux mode */
99 	tmp = RREG32(chan->rec.mask_clk_reg);
100 	tmp |= (1 << 16);
101 	WREG32(chan->rec.mask_clk_reg, tmp);
102 
103 	/* setup AUX control register with correct HPD pin */
104 	tmp = RREG32(AUX_CONTROL + aux_offset[instance]);
105 
106 	tmp &= AUX_HPD_SEL(0x7);
107 	tmp |= AUX_HPD_SEL(chan->rec.hpd);
108 	tmp |= AUX_EN | AUX_LS_READ_EN;
109 
110 	WREG32(AUX_CONTROL + aux_offset[instance], tmp);
111 
112 	/* atombios appears to write this twice lets copy it */
113 	WREG32(AUX_SW_CONTROL + aux_offset[instance],
114 	       AUX_SW_WR_BYTES(bytes));
115 	WREG32(AUX_SW_CONTROL + aux_offset[instance],
116 	       AUX_SW_WR_BYTES(bytes));
117 
118 	/* write the data header into the registers */
119 	/* request, address, msg size */
120 	byte = (msg->request << 4) | ((msg->address >> 16) & 0xf);
121 	WREG32(AUX_SW_DATA + aux_offset[instance],
122 	       AUX_SW_DATA_MASK(byte) | AUX_SW_AUTOINCREMENT_DISABLE);
123 
124 	byte = (msg->address >> 8) & 0xff;
125 	WREG32(AUX_SW_DATA + aux_offset[instance],
126 	       AUX_SW_DATA_MASK(byte));
127 
128 	byte = msg->address & 0xff;
129 	WREG32(AUX_SW_DATA + aux_offset[instance],
130 	       AUX_SW_DATA_MASK(byte));
131 
132 	byte = msize;
133 	WREG32(AUX_SW_DATA + aux_offset[instance],
134 	       AUX_SW_DATA_MASK(byte));
135 
136 	/* if we are writing - write the msg buffer */
137 	if (is_write) {
138 		for (i = 0; i < msg->size; i++) {
139 			WREG32(AUX_SW_DATA + aux_offset[instance],
140 			       AUX_SW_DATA_MASK(buf[i]));
141 		}
142 	}
143 
144 	/* clear the ACK */
145 	WREG32(AUX_SW_INTERRUPT_CONTROL + aux_offset[instance], AUX_SW_DONE_ACK);
146 
147 	/* write the size and GO bits */
148 	WREG32(AUX_SW_CONTROL + aux_offset[instance],
149 	       AUX_SW_WR_BYTES(bytes) | AUX_SW_GO);
150 
151 	/* poll the status registers - TODO irq support */
152 	do {
153 		tmp = RREG32(AUX_SW_STATUS + aux_offset[instance]);
154 		if (tmp & AUX_SW_DONE) {
155 			break;
156 		}
157 		usleep_range(100, 200);
158 	} while (retry_count++ < 1000);
159 
160 	if (retry_count >= 1000) {
161 		DRM_ERROR("auxch hw never signalled completion, error %08x\n", tmp);
162 		ret = -EIO;
163 		goto done;
164 	}
165 
166 	if (tmp & AUX_SW_RX_TIMEOUT) {
167 		ret = -ETIMEDOUT;
168 		goto done;
169 	}
170 	if (tmp & AUX_RX_ERROR_FLAGS) {
171 		DRM_DEBUG_KMS_RATELIMITED("dp_aux_ch flags not zero: %08x\n",
172 					  tmp);
173 		ret = -EIO;
174 		goto done;
175 	}
176 
177 	bytes = AUX_SW_REPLY_GET_BYTE_COUNT(tmp);
178 	if (bytes) {
179 		WREG32(AUX_SW_DATA + aux_offset[instance],
180 		       AUX_SW_DATA_RW | AUX_SW_AUTOINCREMENT_DISABLE);
181 
182 		tmp = RREG32(AUX_SW_DATA + aux_offset[instance]);
183 		ack = (tmp >> 8) & 0xff;
184 
185 		for (i = 0; i < bytes - 1; i++) {
186 			tmp = RREG32(AUX_SW_DATA + aux_offset[instance]);
187 			if (buf)
188 				buf[i] = (tmp >> 8) & 0xff;
189 		}
190 		if (buf)
191 			ret = bytes - 1;
192 	}
193 
194 	WREG32(AUX_SW_INTERRUPT_CONTROL + aux_offset[instance], AUX_SW_DONE_ACK);
195 
196 	if (is_write)
197 		ret = msg->size;
198 done:
199 	mutex_unlock(&chan->mutex);
200 
201 	if (ret >= 0)
202 		msg->reply = ack >> 4;
203 	return ret;
204 }
205