1/*	$NetBSD: nouveau_nvkm_subdev_i2c_auxg94.c,v 1.3 2021/12/18 23:45:40 riastradh Exp $	*/
2
3/*
4 * Copyright 2015 Red Hat Inc.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial busions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * Authors: Ben Skeggs <bskeggs@redhat.com>
25 */
26#include <sys/cdefs.h>
27__KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_i2c_auxg94.c,v 1.3 2021/12/18 23:45:40 riastradh Exp $");
28
29#define g94_i2c_aux(p) container_of((p), struct g94_i2c_aux, base)
30#include "aux.h"
31
32struct g94_i2c_aux {
33	struct nvkm_i2c_aux base;
34	int ch;
35};
36
37static void
38g94_i2c_aux_fini(struct g94_i2c_aux *aux)
39{
40	struct nvkm_device *device = aux->base.pad->i2c->subdev.device;
41	nvkm_mask(device, 0x00e4e4 + (aux->ch * 0x50), 0x00310000, 0x00000000);
42}
43
44static int
45g94_i2c_aux_init(struct g94_i2c_aux *aux)
46{
47	struct nvkm_device *device = aux->base.pad->i2c->subdev.device;
48	const u32 unksel = 1; /* nfi which to use, or if it matters.. */
49	const u32 ureq = unksel ? 0x00100000 : 0x00200000;
50	const u32 urep = unksel ? 0x01000000 : 0x02000000;
51	u32 ctrl, timeout;
52
53	/* wait up to 1ms for any previous transaction to be done... */
54	timeout = 1000;
55	do {
56		ctrl = nvkm_rd32(device, 0x00e4e4 + (aux->ch * 0x50));
57		udelay(1);
58		if (!timeout--) {
59			AUX_ERR(&aux->base, "begin idle timeout %08x", ctrl);
60			return -EBUSY;
61		}
62	} while (ctrl & 0x03010000);
63
64	/* set some magic, and wait up to 1ms for it to appear */
65	nvkm_mask(device, 0x00e4e4 + (aux->ch * 0x50), 0x00300000, ureq);
66	timeout = 1000;
67	do {
68		ctrl = nvkm_rd32(device, 0x00e4e4 + (aux->ch * 0x50));
69		udelay(1);
70		if (!timeout--) {
71			AUX_ERR(&aux->base, "magic wait %08x", ctrl);
72			g94_i2c_aux_fini(aux);
73			return -EBUSY;
74		}
75	} while ((ctrl & 0x03000000) != urep);
76
77	return 0;
78}
79
80int
81g94_i2c_aux_xfer(struct nvkm_i2c_aux *obj, bool retry,
82		 u8 type, u32 addr, u8 *data, u8 *size)
83{
84	struct g94_i2c_aux *aux = g94_i2c_aux(obj);
85	struct nvkm_device *device = aux->base.pad->i2c->subdev.device;
86	const u32 base = aux->ch * 0x50;
87	u32 ctrl, stat, timeout, retries = 0;
88	u32 xbuf[4] = {};
89	int ret, i;
90
91	AUX_TRACE(&aux->base, "%d: %08x %d", type, addr, *size);
92
93	ret = g94_i2c_aux_init(aux);
94	if (ret < 0)
95		goto out;
96
97	stat = nvkm_rd32(device, 0x00e4e8 + base);
98	if (!(stat & 0x10000000)) {
99		AUX_TRACE(&aux->base, "sink not detected");
100		ret = -ENXIO;
101		goto out;
102	}
103
104	if (!(type & 1)) {
105		memcpy(xbuf, data, *size);
106		for (i = 0; i < 16; i += 4) {
107			AUX_TRACE(&aux->base, "wr %08x", xbuf[i / 4]);
108			nvkm_wr32(device, 0x00e4c0 + base + i, xbuf[i / 4]);
109		}
110	}
111
112	ctrl  = nvkm_rd32(device, 0x00e4e4 + base);
113	ctrl &= ~0x0001f1ff;
114	ctrl |= type << 12;
115	ctrl |= (*size ? (*size - 1) : 0x00000100);
116	nvkm_wr32(device, 0x00e4e0 + base, addr);
117
118	/* (maybe) retry transaction a number of times on failure... */
119	do {
120		/* reset, and delay a while if this is a retry */
121		nvkm_wr32(device, 0x00e4e4 + base, 0x80000000 | ctrl);
122		nvkm_wr32(device, 0x00e4e4 + base, 0x00000000 | ctrl);
123		if (retries)
124			udelay(400);
125
126		/* transaction request, wait up to 1ms for it to complete */
127		nvkm_wr32(device, 0x00e4e4 + base, 0x00010000 | ctrl);
128
129		timeout = 1000;
130		do {
131			ctrl = nvkm_rd32(device, 0x00e4e4 + base);
132			udelay(1);
133			if (!timeout--) {
134				AUX_ERR(&aux->base, "timeout %08x", ctrl);
135				ret = -EIO;
136				goto out;
137			}
138		} while (ctrl & 0x00010000);
139		ret = 0;
140
141		/* read status, and check if transaction completed ok */
142		stat = nvkm_mask(device, 0x00e4e8 + base, 0, 0);
143		if ((stat & 0x000f0000) == 0x00080000 ||
144		    (stat & 0x000f0000) == 0x00020000)
145			ret = 1;
146		if ((stat & 0x00000100))
147			ret = -ETIMEDOUT;
148		if ((stat & 0x00000e00))
149			ret = -EIO;
150
151		AUX_TRACE(&aux->base, "%02d %08x %08x", retries, ctrl, stat);
152	} while (ret && retry && retries++ < 32);
153
154	if (type & 1) {
155		for (i = 0; i < 16; i += 4) {
156			xbuf[i / 4] = nvkm_rd32(device, 0x00e4d0 + base + i);
157			AUX_TRACE(&aux->base, "rd %08x", xbuf[i / 4]);
158		}
159		memcpy(data, xbuf, *size);
160		*size = stat & 0x0000001f;
161	}
162
163out:
164	g94_i2c_aux_fini(aux);
165	return ret < 0 ? ret : (stat & 0x000f0000) >> 16;
166}
167
168int
169g94_i2c_aux_new_(const struct nvkm_i2c_aux_func *func,
170		 struct nvkm_i2c_pad *pad, int index, u8 drive,
171		 struct nvkm_i2c_aux **paux)
172{
173	struct g94_i2c_aux *aux;
174
175	if (!(aux = kzalloc(sizeof(*aux), GFP_KERNEL)))
176		return -ENOMEM;
177	*paux = &aux->base;
178
179	nvkm_i2c_aux_ctor(func, pad, index, &aux->base);
180	aux->ch = drive;
181	aux->base.intr = 1 << aux->ch;
182	return 0;
183}
184
185static const struct nvkm_i2c_aux_func
186g94_i2c_aux = {
187	.xfer = g94_i2c_aux_xfer,
188};
189
190int
191g94_i2c_aux_new(struct nvkm_i2c_pad *pad, int index, u8 drive,
192		struct nvkm_i2c_aux **paux)
193{
194	return g94_i2c_aux_new_(&g94_i2c_aux, pad, index, drive, paux);
195}
196