LXR linux/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
  29struct nv50_i2c_bus {
  30        struct nvkm_i2c_bus base;
  31        u32 addr;
  32        u32 data;
  33};
  34
  35static void
  36nv50_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
  45static void
  46nv50_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
  55static int
  56nv50_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
  63static int
  64nv50_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
  71static void
  72nv50_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
  79static const struct nvkm_i2c_bus_func
  80nv50_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
  89int
  90nv50_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}
 114