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
  26 int
  27 nv_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
  41 int
  42 nv_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
  56 static int
  57 aux_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
 104 static u32
 105 aux_func(struct i2c_adapter *adap)
 106 {
 107         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 108 }
 109
 110 const struct i2c_algorithm nvkm_i2c_aux_algo = {
 111         .master_xfer = aux_xfer,
 112         .functionality = aux_func
 113 };