LXR linux/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.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#include "priv.h"
  25
  26int
  27nv_rdaux(struct nvkm_i2c_port *port, u32 addr, u8 *data, u8 size)
  28{
  29        struct nvkm_i2c *i2c = nvkm_i2c(port);
  30        if (port->func->aux) {
  31                int ret = i2c->acquire(port, 0);
  32                if (ret == 0) {
  33                        ret = port->func->aux(port, true, 9, addr, data, size);
  34                        i2c->release(port);
  35                }
  36                return ret;
  37        }
  38        return -ENODEV;
  39}
  40
  41int
  42nv_wraux(struct nvkm_i2c_port *port, u32 addr, u8 *data, u8 size)
  43{
  44        struct nvkm_i2c *i2c = nvkm_i2c(port);
  45        if (port->func->aux) {
  46                int ret = i2c->acquire(port, 0);
  47                if (ret == 0) {
  48                        ret = port->func->aux(port, true, 8, addr, data, size);
  49                        i2c->release(port);
  50                }
  51                return ret;
  52        }
  53        return -ENODEV;
  54}
  55
  56static int
  57aux_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
  58{
  59        struct nvkm_i2c_port *port = adap->algo_data;
  60        struct nvkm_i2c *i2c = nvkm_i2c(port);
  61        struct i2c_msg *msg = msgs;
  62        int ret, mcnt = num;
  63
  64        if (!port->func->aux)
  65                return -ENODEV;
  66
  67        ret = i2c->acquire(port, 0);
  68        if (ret)
  69                return ret;
  70
  71        while (mcnt--) {
  72                u8 remaining = msg->len;
  73                u8 *ptr = msg->buf;
  74
  75                while (remaining) {
  76                        u8 cnt = (remaining > 16) ? 16 : remaining;
  77                        u8 cmd;
  78
  79                        if (msg->flags & I2C_M_RD)
  80                                cmd = 1;
  81                        else
  82                                cmd = 0;
  83
  84                        if (mcnt || remaining > 16)
  85                                cmd |= 4; /* MOT */
  86
  87                        ret = port->func->aux(port, true, cmd, msg->addr, ptr, cnt);
  88                        if (ret < 0) {
  89                                i2c->release(port);
  90                                return ret;
  91                        }
  92
  93                        ptr += cnt;
  94                        remaining -= cnt;
  95                }
  96
  97                msg++;
  98        }
  99
 100        i2c->release(port);
 101        return num;
 102}
 103
 104static u32
 105aux_func(struct i2c_adapter *adap)
 106{
 107        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 108}
 109
 110const struct i2c_algorithm nvkm_i2c_aux_algo = {
 111        .master_xfer = aux_xfer,
 112        .functionality = aux_func
 113};
 114