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 busions 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: Ben Skeggs <bskeggs@redhat.com>
23  */
24 #define g94_i2c_aux(p) container_of((p), struct g94_i2c_aux, base)
25 #include "aux.h"
26 
27 struct g94_i2c_aux {
28 	struct nvkm_i2c_aux base;
29 	int ch;
30 };
31 
32 static void
33 g94_i2c_aux_fini(struct g94_i2c_aux *aux)
34 {
35 	struct nvkm_device *device = aux->base.pad->i2c->subdev.device;
36 	nvkm_mask(device, 0x00e4e4 + (aux->ch * 0x50), 0x00310000, 0x00000000);
37 }
38 
39 static int
40 g94_i2c_aux_init(struct g94_i2c_aux *aux)
41 {
42 	struct nvkm_device *device = aux->base.pad->i2c->subdev.device;
43 	const u32 unksel = 1; /* nfi which to use, or if it matters.. */
44 	const u32 ureq = unksel ? 0x00100000 : 0x00200000;
45 	const u32 urep = unksel ? 0x01000000 : 0x02000000;
46 	u32 ctrl, timeout;
47 
48 	/* wait up to 1ms for any previous transaction to be done... */
49 	timeout = 1000;
50 	do {
51 		ctrl = nvkm_rd32(device, 0x00e4e4 + (aux->ch * 0x50));
52 		udelay(1);
53 		if (!timeout--) {
54 			AUX_ERR(&aux->base, "begin idle timeout %08x", ctrl);
55 			return -EBUSY;
56 		}
57 	} while (ctrl & 0x03010000);
58 
59 	/* set some magic, and wait up to 1ms for it to appear */
60 	nvkm_mask(device, 0x00e4e4 + (aux->ch * 0x50), 0x00300000, ureq);
61 	timeout = 1000;
62 	do {
63 		ctrl = nvkm_rd32(device, 0x00e4e4 + (aux->ch * 0x50));
64 		udelay(1);
65 		if (!timeout--) {
66 			AUX_ERR(&aux->base, "magic wait %08x", ctrl);
67 			g94_i2c_aux_fini(aux);
68 			return -EBUSY;
69 		}
70 	} while ((ctrl & 0x03000000) != urep);
71 
72 	return 0;
73 }
74 
75 int
76 g94_i2c_aux_xfer(struct nvkm_i2c_aux *obj, bool retry,
77 		 u8 type, u32 addr, u8 *data, u8 *size)
78 {
79 	struct g94_i2c_aux *aux = g94_i2c_aux(obj);
80 	struct nvkm_i2c *i2c = aux->base.pad->i2c;
81 	struct nvkm_device *device = i2c->subdev.device;
82 	const u32 base = aux->ch * 0x50;
83 	u32 ctrl, stat, timeout, retries = 0;
84 	u32 xbuf[4] = {};
85 	int ret, i;
86 
87 	AUX_TRACE(&aux->base, "%d: %08x %d", type, addr, *size);
88 
89 	ret = g94_i2c_aux_init(aux);
90 	if (ret < 0)
91 		goto out;
92 
93 	stat = nvkm_rd32(device, 0x00e4e8 + base);
94 	if (!(stat & 0x10000000)) {
95 		AUX_TRACE(&aux->base, "sink not detected");
96 		ret = -ENXIO;
97 		goto out;
98 	}
99 
100 	nvkm_i2c_aux_autodpcd(i2c, aux->ch, false);
101 
102 	if (!(type & 1)) {
103 		memcpy(xbuf, data, *size);
104 		for (i = 0; i < 16; i += 4) {
105 			AUX_TRACE(&aux->base, "wr %08x", xbuf[i / 4]);
106 			nvkm_wr32(device, 0x00e4c0 + base + i, xbuf[i / 4]);
107 		}
108 	}
109 
110 	ctrl  = nvkm_rd32(device, 0x00e4e4 + base);
111 	ctrl &= ~0x0001f1ff;
112 	ctrl |= type << 12;
113 	ctrl |= (*size ? (*size - 1) : 0x00000100);
114 	nvkm_wr32(device, 0x00e4e0 + base, addr);
115 
116 	/* (maybe) retry transaction a number of times on failure... */
117 	do {
118 		/* reset, and delay a while if this is a retry */
119 		nvkm_wr32(device, 0x00e4e4 + base, 0x80000000 | ctrl);
120 		nvkm_wr32(device, 0x00e4e4 + base, 0x00000000 | ctrl);
121 		if (retries)
122 			udelay(400);
123 
124 		/* transaction request, wait up to 2ms for it to complete */
125 		nvkm_wr32(device, 0x00e4e4 + base, 0x00010000 | ctrl);
126 
127 		timeout = 2000;
128 		do {
129 			ctrl = nvkm_rd32(device, 0x00e4e4 + base);
130 			udelay(1);
131 			if (!timeout--) {
132 				AUX_ERR(&aux->base, "timeout %08x", ctrl);
133 				ret = -EIO;
134 				goto out_err;
135 			}
136 		} while (ctrl & 0x00010000);
137 		ret = 0;
138 
139 		/* read status, and check if transaction completed ok */
140 		stat = nvkm_mask(device, 0x00e4e8 + base, 0, 0);
141 		if ((stat & 0x000f0000) == 0x00080000 ||
142 		    (stat & 0x000f0000) == 0x00020000)
143 			ret = 1;
144 		if ((stat & 0x00000100))
145 			ret = -ETIMEDOUT;
146 		if ((stat & 0x00000e00))
147 			ret = -EIO;
148 
149 		AUX_TRACE(&aux->base, "%02d %08x %08x", retries, ctrl, stat);
150 	} while (ret && retry && retries++ < 32);
151 
152 	if (type & 1) {
153 		for (i = 0; i < 16; i += 4) {
154 			xbuf[i / 4] = nvkm_rd32(device, 0x00e4d0 + base + i);
155 			AUX_TRACE(&aux->base, "rd %08x", xbuf[i / 4]);
156 		}
157 		memcpy(data, xbuf, *size);
158 		*size = stat & 0x0000001f;
159 	}
160 out_err:
161 	nvkm_i2c_aux_autodpcd(i2c, aux->ch, true);
162 out:
163 	g94_i2c_aux_fini(aux);
164 	return ret < 0 ? ret : (stat & 0x000f0000) >> 16;
165 }
166 
167 int
168 g94_i2c_aux_new_(const struct nvkm_i2c_aux_func *func,
169 		 struct nvkm_i2c_pad *pad, int index, u8 drive,
170 		 struct nvkm_i2c_aux **paux)
171 {
172 	struct g94_i2c_aux *aux;
173 
174 	if (!(aux = kzalloc(sizeof(*aux), GFP_KERNEL)))
175 		return -ENOMEM;
176 	*paux = &aux->base;
177 
178 	nvkm_i2c_aux_ctor(func, pad, index, &aux->base);
179 	aux->ch = drive;
180 	aux->base.intr = 1 << aux->ch;
181 	return 0;
182 }
183 
184 static const struct nvkm_i2c_aux_func
185 g94_i2c_aux = {
186 	.xfer = g94_i2c_aux_xfer,
187 };
188 
189 int
190 g94_i2c_aux_new(struct nvkm_i2c_pad *pad, int index, u8 drive,
191 		struct nvkm_i2c_aux **paux)
192 {
193 	return g94_i2c_aux_new_(&g94_i2c_aux, pad, index, drive, paux);
194 }
195