drivers/gpu/drm/nouveau/nvkm/subdev/i2c/busnv50.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 nv50_i2c_bus(p) container_of((p), struct nv50_i2c_bus, base)
  25 #include "bus.h"
  26
  27 #include <subdev/vga.h>
  28
  29 struct nv50_i2c_bus {
  30         struct nvkm_i2c_bus base;
  31         u32 addr;
  32         u32 data;
  33 };
  34
  35 static void
  36 nv50_i2c_bus_drive_scl(struct nvkm_i2c_bus *base, int state)
  37 {
  38         struct nv50_i2c_bus *bus = nv50_i2c_bus(base);
  39         struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
  40         if (state) bus->data |= 0x01;
  41         else       bus->data &= 0xfe;
  42         nvkm_wr32(device, bus->addr, bus->data);
  43 }
  44
  45 static void
  46 nv50_i2c_bus_drive_sda(struct nvkm_i2c_bus *base, int state)
  47 {
  48         struct nv50_i2c_bus *bus = nv50_i2c_bus(base);
  49         struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
  50         if (state) bus->data |= 0x02;
  51         else       bus->data &= 0xfd;
  52         nvkm_wr32(device, bus->addr, bus->data);
  53 }
  54
  55 static int
  56 nv50_i2c_bus_sense_scl(struct nvkm_i2c_bus *base)
  57 {
  58         struct nv50_i2c_bus *bus = nv50_i2c_bus(base);
  59         struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
  60         return !!(nvkm_rd32(device, bus->addr) & 0x00000001);
  61 }
  62
  63 static int
  64 nv50_i2c_bus_sense_sda(struct nvkm_i2c_bus *base)
  65 {
  66         struct nv50_i2c_bus *bus = nv50_i2c_bus(base);
  67         struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
  68         return !!(nvkm_rd32(device, bus->addr) & 0x00000002);
  69 }
  70
  71 static void
  72 nv50_i2c_bus_init(struct nvkm_i2c_bus *base)
  73 {
  74         struct nv50_i2c_bus *bus = nv50_i2c_bus(base);
  75         struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
  76         nvkm_wr32(device, bus->addr, (bus->data = 0x00000007));
  77 }
  78
  79 static const struct nvkm_i2c_bus_func
  80 nv50_i2c_bus_func = {
  81         .init = nv50_i2c_bus_init,
  82         .drive_scl = nv50_i2c_bus_drive_scl,
  83         .drive_sda = nv50_i2c_bus_drive_sda,
  84         .sense_scl = nv50_i2c_bus_sense_scl,
  85         .sense_sda = nv50_i2c_bus_sense_sda,
  86         .xfer = nvkm_i2c_bit_xfer,
  87 };
  88
  89 int
  90 nv50_i2c_bus_new(struct nvkm_i2c_pad *pad, int id, u8 drive,
  91                  struct nvkm_i2c_bus **pbus)
  92 {
  93         static const u32 addr[] = {
  94                 0x00e138, 0x00e150, 0x00e168, 0x00e180,
  95                 0x00e254, 0x00e274, 0x00e764, 0x00e780,
  96                 0x00e79c, 0x00e7b8
  97         };
  98         struct nv50_i2c_bus *bus;
  99
 100         if (drive >= ARRAY_SIZE(addr)) {
 101                 nvkm_warn(&pad->i2c->subdev, "bus %d unknown\n", drive);
 102                 return -ENODEV;
 103         }
 104
 105         if (!(bus = kzalloc(sizeof(*bus), GFP_KERNEL)))
 106                 return -ENOMEM;
 107         *pbus = &bus->base;
 108
 109         nvkm_i2c_bus_ctor(&nv50_i2c_bus_func, pad, id, &bus->base);
 110         bus->addr = addr[drive];
 111         bus->data = 0x00000007;
 112         return 0;
 113 }