LXR linux/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
  29struct nv04_i2c_bus {
  30        struct nvkm_i2c_bus base;
  31        u8 drive;
  32        u8 sense;
  33};
  34
  35static void
  36nv04_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
  46static void
  47nv04_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
  57static int
  58nv04_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
  65static int
  66nv04_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
  73static const struct nvkm_i2c_bus_func
  74nv04_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
  82int
  83nv04_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}
  97