auxch.c

  1/*
  2 * Copyright 2009 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: Ben Skeggs
 23 */
 24
 25#include <linux/string_helpers.h>
 26
 27#include "auxch.h"
 28#include "pad.h"
 29
 30static int
 31nvkm_i2c_aux_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 32{
 33	struct nvkm_i2c_aux *aux = container_of(adap, typeof(*aux), i2c);
 34	struct i2c_msg *msg = msgs;
 35	int ret, mcnt = num;
 36
 37	ret = nvkm_i2c_aux_acquire(aux);
 38	if (ret)
 39		return ret;
 40
 41	while (mcnt--) {
 42		u8 remaining = msg->len;
 43		u8 *ptr = msg->buf;
 44
 45		while (remaining) {
 46			u8 cnt, retries, cmd;
 47
 48			if (msg->flags & I2C_M_RD)
 49				cmd = 1;
 50			else
 51				cmd = 0;
 52
 53			if (mcnt || remaining > 16)
 54				cmd |= 4; /* MOT */
 55
 56			for (retries = 0, cnt = 0;
 57			     retries < 32 && !cnt;
 58			     retries++) {
 59				cnt = min_t(u8, remaining, 16);
 60				ret = aux->func->xfer(aux, true, cmd,
 61						      msg->addr, ptr, &cnt);
 62				if (ret < 0)
 63					goto out;
 64			}
 65			if (!cnt) {
 66				AUX_TRACE(aux, "no data after 32 retries");
 67				ret = -EIO;
 68				goto out;
 69			}
 70
 71			ptr += cnt;
 72			remaining -= cnt;
 73		}
 74
 75		msg++;
 76	}
 77
 78	ret = num;
 79out:
 80	nvkm_i2c_aux_release(aux);
 81	return ret;
 82}
 83
 84static u32
 85nvkm_i2c_aux_i2c_func(struct i2c_adapter *adap)
 86{
 87	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 88}
 89
 90static const struct i2c_algorithm
 91nvkm_i2c_aux_i2c_algo = {
 92	.master_xfer = nvkm_i2c_aux_i2c_xfer,
 93	.functionality = nvkm_i2c_aux_i2c_func
 94};
 95
 96void
 97nvkm_i2c_aux_monitor(struct nvkm_i2c_aux *aux, bool monitor)
 98{
 99	struct nvkm_i2c_pad *pad = aux->pad;
100	AUX_TRACE(aux, "monitor: %s", str_yes_no(monitor));
101	if (monitor)
102		nvkm_i2c_pad_mode(pad, NVKM_I2C_PAD_AUX);
103	else
104		nvkm_i2c_pad_mode(pad, NVKM_I2C_PAD_OFF);
105}
106
107void
108nvkm_i2c_aux_release(struct nvkm_i2c_aux *aux)
109{
110	struct nvkm_i2c_pad *pad = aux->pad;
111	AUX_TRACE(aux, "release");
112	nvkm_i2c_pad_release(pad);
113	mutex_unlock(&aux->mutex);
114}
115
116int
117nvkm_i2c_aux_acquire(struct nvkm_i2c_aux *aux)
118{
119	struct nvkm_i2c_pad *pad = aux->pad;
120	int ret;
121
122	AUX_TRACE(aux, "acquire");
123	mutex_lock(&aux->mutex);
124
125	if (aux->enabled)
126		ret = nvkm_i2c_pad_acquire(pad, NVKM_I2C_PAD_AUX);
127	else
128		ret = -EIO;
129
130	if (ret)
131		mutex_unlock(&aux->mutex);
132	return ret;
133}
134
135int
136nvkm_i2c_aux_xfer(struct nvkm_i2c_aux *aux, bool retry, u8 type,
137		  u32 addr, u8 *data, u8 *size)
138{
139	if (!*size && !aux->func->address_only) {
140		AUX_ERR(aux, "address-only transaction dropped");
141		return -ENOSYS;
142	}
143	return aux->func->xfer(aux, retry, type, addr, data, size);
144}
145
146int
147nvkm_i2c_aux_lnk_ctl(struct nvkm_i2c_aux *aux, int nr, int bw, bool ef)
148{
149	if (aux->func->lnk_ctl)
150		return aux->func->lnk_ctl(aux, nr, bw, ef);
151	return -ENODEV;
152}
153
154void
155nvkm_i2c_aux_del(struct nvkm_i2c_aux **paux)
156{
157	struct nvkm_i2c_aux *aux = *paux;
158	if (aux && !WARN_ON(!aux->func)) {
159		AUX_TRACE(aux, "dtor");
160		list_del(&aux->head);
161		i2c_del_adapter(&aux->i2c);
162		kfree(*paux);
163		*paux = NULL;
164	}
165}
166
167void
168nvkm_i2c_aux_init(struct nvkm_i2c_aux *aux)
169{
170	AUX_TRACE(aux, "init");
171	mutex_lock(&aux->mutex);
172	aux->enabled = true;
173	mutex_unlock(&aux->mutex);
174}
175
176void
177nvkm_i2c_aux_fini(struct nvkm_i2c_aux *aux)
178{
179	AUX_TRACE(aux, "fini");
180	mutex_lock(&aux->mutex);
181	aux->enabled = false;
182	mutex_unlock(&aux->mutex);
183}
184
185int
186nvkm_i2c_aux_ctor(const struct nvkm_i2c_aux_func *func,
187		  struct nvkm_i2c_pad *pad, int id,
188		  struct nvkm_i2c_aux *aux)
189{
190	struct nvkm_device *device = pad->i2c->subdev.device;
191
192	aux->func = func;
193	aux->pad = pad;
194	aux->id = id;
195	mutex_init(&aux->mutex);
196	list_add_tail(&aux->head, &pad->i2c->aux);
197	AUX_TRACE(aux, "ctor");
198
199	snprintf(aux->i2c.name, sizeof(aux->i2c.name), "nvkm-%s-aux-%04x",
200		 dev_name(device->dev), id);
201	aux->i2c.owner = THIS_MODULE;
202	aux->i2c.dev.parent = device->dev;
203	aux->i2c.algo = &nvkm_i2c_aux_i2c_algo;
204	return i2c_add_adapter(&aux->i2c);
205}
206
207int
208nvkm_i2c_aux_new_(const struct nvkm_i2c_aux_func *func,
209		  struct nvkm_i2c_pad *pad, int id,
210		  struct nvkm_i2c_aux **paux)
211{
212	if (!(*paux = kzalloc(sizeof(**paux), GFP_KERNEL)))
213		return -ENOMEM;
214	return nvkm_i2c_aux_ctor(func, pad, id, *paux);
215}