drivers/gpu/drm/nouveau/core/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
  25 #include "priv.h"
  26
  27 int
  28 nv_rdaux(struct nouveau_i2c_port *port, u32 addr, u8 *data, u8 size)
  29 {
  30         if (port->func->aux) {
  31                 if (port->func->acquire)
  32                         port->func->acquire(port);
  33                 return port->func->aux(port, true, 9, addr, data, size);
  34         }
  35         return -ENODEV;
  36 }
  37
  38 int
  39 nv_wraux(struct nouveau_i2c_port *port, u32 addr, u8 *data, u8 size)
  40 {
  41         if (port->func->aux) {
  42                 if (port->func->acquire)
  43                         port->func->acquire(port);
  44                 return port->func->aux(port, true, 8, addr, data, size);
  45         }
  46         return -ENODEV;
  47 }
  48
  49 static int
  50 aux_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
  51 {
  52         struct nouveau_i2c_port *port = adap->algo_data;
  53         struct i2c_msg *msg = msgs;
  54         int ret, mcnt = num;
  55
  56         if (!port->func->aux)
  57                 return -ENODEV;
  58         if ( port->func->acquire)
  59                 port->func->acquire(port);
  60
  61         while (mcnt--) {
  62                 u8 remaining = msg->len;
  63                 u8 *ptr = msg->buf;
  64
  65                 while (remaining) {
  66                         u8 cnt = (remaining > 16) ? 16 : remaining;
  67                         u8 cmd;
  68
  69                         if (msg->flags & I2C_M_RD)
  70                                 cmd = 1;
  71                         else
  72                                 cmd = 0;
  73
  74                         if (mcnt || remaining > 16)
  75                                 cmd |= 4; /* MOT */
  76
  77                         ret = port->func->aux(port, true, cmd, msg->addr, ptr, cnt);
  78                         if (ret < 0)
  79                                 return ret;
  80
  81                         ptr += cnt;
  82                         remaining -= cnt;
  83                 }
  84
  85                 msg++;
  86         }
  87
  88         return num;
  89 }
  90
  91 static u32
  92 aux_func(struct i2c_adapter *adap)
  93 {
  94         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
  95 }
  96
  97 const struct i2c_algorithm nouveau_i2c_aux_algo = {
  98         .master_xfer = aux_xfer,
  99         .functionality = aux_func
 100 };