drivers/gpu/drm/nouveau/nvkm/subdev/i2c/busnv04.c

   1 /*
   2  * Copyright 2015 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 busions 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 <bskeggs@redhat.com>
  23  */
  24 #define nv04_i2c_bus(p) container_of((p), struct nv04_i2c_bus, base)
  25 #include "bus.h"
  26
  27 #include <subdev/vga.h>
  28
  29 struct nv04_i2c_bus {
  30         struct nvkm_i2c_bus base;
  31         u8 drive;
  32         u8 sense;
  33 };
  34
  35 static void
  36 nv04_i2c_bus_drive_scl(struct nvkm_i2c_bus *base, int state)
  37 {
  38         struct nv04_i2c_bus *bus = nv04_i2c_bus(base);
  39         struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
  40         u8 val = nvkm_rdvgac(device, 0, bus->drive);
  41         if (state) val |= 0x20;
  42         else       val &= 0xdf;
  43         nvkm_wrvgac(device, 0, bus->drive, val | 0x01);
  44 }
  45
  46 static void
  47 nv04_i2c_bus_drive_sda(struct nvkm_i2c_bus *base, int state)
  48 {
  49         struct nv04_i2c_bus *bus = nv04_i2c_bus(base);
  50         struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
  51         u8 val = nvkm_rdvgac(device, 0, bus->drive);
  52         if (state) val |= 0x10;
  53         else       val &= 0xef;
  54         nvkm_wrvgac(device, 0, bus->drive, val | 0x01);
  55 }
  56
  57 static int
  58 nv04_i2c_bus_sense_scl(struct nvkm_i2c_bus *base)
  59 {
  60         struct nv04_i2c_bus *bus = nv04_i2c_bus(base);
  61         struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
  62         return !!(nvkm_rdvgac(device, 0, bus->sense) & 0x04);
  63 }
  64
  65 static int
  66 nv04_i2c_bus_sense_sda(struct nvkm_i2c_bus *base)
  67 {
  68         struct nv04_i2c_bus *bus = nv04_i2c_bus(base);
  69         struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
  70         return !!(nvkm_rdvgac(device, 0, bus->sense) & 0x08);
  71 }
  72
  73 static const struct nvkm_i2c_bus_func
  74 nv04_i2c_bus_func = {
  75         .drive_scl = nv04_i2c_bus_drive_scl,
  76         .drive_sda = nv04_i2c_bus_drive_sda,
  77         .sense_scl = nv04_i2c_bus_sense_scl,
  78         .sense_sda = nv04_i2c_bus_sense_sda,
  79         .xfer = nvkm_i2c_bit_xfer,
  80 };
  81
  82 int
  83 nv04_i2c_bus_new(struct nvkm_i2c_pad *pad, int id, u8 drive, u8 sense,
  84                  struct nvkm_i2c_bus **pbus)
  85 {
  86         struct nv04_i2c_bus *bus;
  87
  88         if (!(bus = kzalloc(sizeof(*bus), GFP_KERNEL)))
  89                 return -ENOMEM;
  90         *pbus = &bus->base;
  91
  92         nvkm_i2c_bus_ctor(&nv04_i2c_bus_func, pad, id, &bus->base);
  93         bus->drive = drive;
  94         bus->sense = sense;
  95         return 0;
  96 }