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 gm204_i2c_aux(p) container_of((p), struct gm204_i2c_aux, base)
25#include "aux.h"
26
27struct gm204_i2c_aux {
28	struct nvkm_i2c_aux base;
29	int ch;
30};
31
32static void
33gm204_i2c_aux_fini(struct gm204_i2c_aux *aux)
34{
35	struct nvkm_device *device = aux->base.pad->i2c->subdev.device;
36	nvkm_mask(device, 0x00d954 + (aux->ch * 0x50), 0x00310000, 0x00000000);
37}
38
39static int
40gm204_i2c_aux_init(struct gm204_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, 0x00d954 + (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, 0x00d954 + (aux->ch * 0x50), 0x00300000, ureq);
61	timeout = 1000;
62	do {
63		ctrl = nvkm_rd32(device, 0x00d954 + (aux->ch * 0x50));
64		udelay(1);
65		if (!timeout--) {
66			AUX_ERR(&aux->base, "magic wait %08x", ctrl);
67			gm204_i2c_aux_fini(aux);
68			return -EBUSY;
69		}
70	} while ((ctrl & 0x03000000) != urep);
71
72	return 0;
73}
74
75static int
76gm204_i2c_aux_xfer(struct nvkm_i2c_aux *obj, bool retry,
77		   u8 type, u32 addr, u8 *data, u8 size)
78{
79	struct gm204_i2c_aux *aux = gm204_i2c_aux(obj);
80	struct nvkm_device *device = aux->base.pad->i2c->subdev.device;
81	const u32 base = aux->ch * 0x50;
82	u32 ctrl, stat, timeout, retries;
83	u32 xbuf[4] = {};
84	int ret, i;
85
86	AUX_TRACE(&aux->base, "%d: %08x %d", type, addr, size);
87
88	ret = gm204_i2c_aux_init(aux);
89	if (ret < 0)
90		goto out;
91
92	stat = nvkm_rd32(device, 0x00d958 + base);
93	if (!(stat & 0x10000000)) {
94		AUX_TRACE(&aux->base, "sink not detected");
95		ret = -ENXIO;
96		goto out;
97	}
98
99	if (!(type & 1)) {
100		memcpy(xbuf, data, size);
101		for (i = 0; i < 16; i += 4) {
102			AUX_TRACE(&aux->base, "wr %08x", xbuf[i / 4]);
103			nvkm_wr32(device, 0x00d930 + base + i, xbuf[i / 4]);
104		}
105	}
106
107	ctrl  = nvkm_rd32(device, 0x00d954 + base);
108	ctrl &= ~0x0001f0ff;
109	ctrl |= type << 12;
110	ctrl |= size - 1;
111	nvkm_wr32(device, 0x00d950 + base, addr);
112
113	/* (maybe) retry transaction a number of times on failure... */
114	for (retries = 0; !ret && retries < 32; retries++) {
115		/* reset, and delay a while if this is a retry */
116		nvkm_wr32(device, 0x00d954 + base, 0x80000000 | ctrl);
117		nvkm_wr32(device, 0x00d954 + base, 0x00000000 | ctrl);
118		if (retries)
119			udelay(400);
120
121		/* transaction request, wait up to 1ms for it to complete */
122		nvkm_wr32(device, 0x00d954 + base, 0x00010000 | ctrl);
123
124		timeout = 1000;
125		do {
126			ctrl = nvkm_rd32(device, 0x00d954 + base);
127			udelay(1);
128			if (!timeout--) {
129				AUX_ERR(&aux->base, "timeout %08x", ctrl);
130				ret = -EIO;
131				goto out;
132			}
133		} while (ctrl & 0x00010000);
134		ret = 1;
135
136		/* read status, and check if transaction completed ok */
137		stat = nvkm_mask(device, 0x00d958 + base, 0, 0);
138		if ((stat & 0x000f0000) == 0x00080000 ||
139		    (stat & 0x000f0000) == 0x00020000)
140			ret = retry ? 0 : 1;
141		if ((stat & 0x00000100))
142			ret = -ETIMEDOUT;
143		if ((stat & 0x00000e00))
144			ret = -EIO;
145
146		AUX_TRACE(&aux->base, "%02d %08x %08x", retries, ctrl, stat);
147	}
148
149	if (type & 1) {
150		for (i = 0; i < 16; i += 4) {
151			xbuf[i / 4] = nvkm_rd32(device, 0x00d940 + base + i);
152			AUX_TRACE(&aux->base, "rd %08x", xbuf[i / 4]);
153		}
154		memcpy(data, xbuf, size);
155	}
156
157out:
158	gm204_i2c_aux_fini(aux);
159	return ret < 0 ? ret : (stat & 0x000f0000) >> 16;
160}
161
162static const struct nvkm_i2c_aux_func
163gm204_i2c_aux_func = {
164	.xfer = gm204_i2c_aux_xfer,
165};
166
167int
168gm204_i2c_aux_new(struct nvkm_i2c_pad *pad, int index, u8 drive,
169		struct nvkm_i2c_aux **paux)
170{
171	struct gm204_i2c_aux *aux;
172
173	if (!(aux = kzalloc(sizeof(*aux), GFP_KERNEL)))
174		return -ENOMEM;
175	*paux = &aux->base;
176
177	nvkm_i2c_aux_ctor(&gm204_i2c_aux_func, pad, index, &aux->base);
178	aux->ch = drive;
179	aux->base.intr = 1 << aux->ch;
180	return 0;
181}
182