sys/powerpc/powermac/nvbl.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause
   3  *
   4  * Copyright (c) 2012 Justin Hibbits
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/param.h>
  30 #include <sys/bus.h>
  31 #include <sys/systm.h>
  32 #include <sys/module.h>
  33 #include <sys/kernel.h>
  34 #include <sys/rman.h>
  35 #include <sys/sysctl.h>
  36
  37 #include <machine/bus.h>
  38
  39 #include <dev/ofw/openfirm.h>
  40 #include <dev/pci/pcivar.h>
  41
  42 #define PCI_VENDOR_ID_NVIDIA    0x10de
  43
  44 #define NVIDIA_BRIGHT_MIN     (0x0ec)
  45 #define NVIDIA_BRIGHT_MAX     (0x538)
  46 #define NVIDIA_BRIGHT_SCALE   ((NVIDIA_BRIGHT_MAX - NVIDIA_BRIGHT_MIN)/100)
  47 /* nVidia's MMIO registers are at PCI BAR[0] */
  48 #define NVIDIA_MMIO_PMC       (0x0)
  49 #define  NVIDIA_PMC_OFF         (NVIDIA_MMIO_PMC + 0x10f0)
  50 #define   NVIDIA_PMC_BL_SHIFT    (16)
  51 #define   NVIDIA_PMC_BL_EN       (1U << 31)
  52
  53 struct nvbl_softc {
  54         device_t         dev;
  55         struct resource *sc_memr;
  56 };
  57
  58 static void nvbl_identify(driver_t *driver, device_t parent);
  59 static int nvbl_probe(device_t dev);
  60 static int nvbl_attach(device_t dev);
  61 static int nvbl_setlevel(struct nvbl_softc *sc, int newlevel);
  62 static int nvbl_getlevel(struct nvbl_softc *sc);
  63 static int nvbl_sysctl(SYSCTL_HANDLER_ARGS);
  64
  65 static device_method_t nvbl_methods[] = {
  66         /* Device interface */
  67         DEVMETHOD(device_identify, nvbl_identify),
  68         DEVMETHOD(device_probe, nvbl_probe),
  69         DEVMETHOD(device_attach, nvbl_attach),
  70         {0, 0},
  71 };
  72
  73 static driver_t nvbl_driver = {
  74         "backlight",
  75         nvbl_methods,
  76         sizeof(struct nvbl_softc)
  77 };
  78
  79 DRIVER_MODULE(nvbl, vgapci, nvbl_driver, 0, 0);
  80
  81 static void
  82 nvbl_identify(driver_t *driver, device_t parent)
  83 {
  84         if (OF_finddevice("mac-io/backlight") == -1)
  85                 return;
  86         if (device_find_child(parent, "backlight", -1) == NULL)
  87                 device_add_child(parent, "backlight", DEVICE_UNIT_ANY);
  88 }
  89
  90 static int
  91 nvbl_probe(device_t dev)
  92 {
  93         char            control[8];
  94         phandle_t       handle;
  95
  96         handle = OF_finddevice("mac-io/backlight");
  97
  98         if (handle == -1)
  99                 return (ENXIO);
 100
 101         if (OF_getprop(handle, "backlight-control", &control, sizeof(control)) < 0)
 102                 return (ENXIO);
 103
 104         if ((strcmp(control, "mnca") != 0) ||
 105             pci_get_vendor(device_get_parent(dev)) != PCI_VENDOR_ID_NVIDIA)
 106                 return (ENXIO);
 107
 108         device_set_desc(dev, "PowerBook backlight for nVidia graphics");
 109
 110         return (0);
 111 }
 112
 113 static int
 114 nvbl_attach(device_t dev)
 115 {
 116         struct nvbl_softc       *sc;
 117         struct sysctl_ctx_list *ctx;
 118         struct sysctl_oid *tree;
 119         int                      rid;
 120
 121         sc = device_get_softc(dev);
 122
 123         rid = 0x10;     /* BAR[0], for the MMIO register */
 124         sc->sc_memr = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
 125                         RF_ACTIVE | RF_SHAREABLE);
 126         if (sc->sc_memr == NULL) {
 127                 device_printf(dev, "Could not alloc mem resource!\n");
 128                 return (ENXIO);
 129         }
 130
 131         /* Turn on big-endian mode */
 132         if (!(bus_read_stream_4(sc->sc_memr, NVIDIA_MMIO_PMC + 4) & 0x01000001)) {
 133                 bus_write_stream_4(sc->sc_memr, NVIDIA_MMIO_PMC + 4, 0x01000001);
 134                 mb();
 135         }
 136
 137         ctx = device_get_sysctl_ctx(dev);
 138         tree = device_get_sysctl_tree(dev);
 139
 140         SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
 141             "level", CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, sc, 0,
 142             nvbl_sysctl, "I", "Backlight level (0-100)");
 143
 144         return (0);
 145 }
 146
 147 static int
 148 nvbl_setlevel(struct nvbl_softc *sc, int newlevel)
 149 {
 150         uint32_t pmc_reg;
 151
 152         if (newlevel > 100)
 153                 newlevel = 100;
 154
 155         if (newlevel < 0)
 156                 newlevel = 0;
 157
 158         if (newlevel > 0)
 159                 newlevel = (newlevel * NVIDIA_BRIGHT_SCALE) + NVIDIA_BRIGHT_MIN;
 160
 161         pmc_reg = bus_read_stream_4(sc->sc_memr, NVIDIA_PMC_OFF) & 0xffff;
 162         pmc_reg |= NVIDIA_PMC_BL_EN | (newlevel << NVIDIA_PMC_BL_SHIFT);
 163         bus_write_stream_4(sc->sc_memr, NVIDIA_PMC_OFF, pmc_reg);
 164
 165         return (0);
 166 }
 167
 168 static int
 169 nvbl_getlevel(struct nvbl_softc *sc)
 170 {
 171         uint16_t level;
 172
 173         level = bus_read_stream_2(sc->sc_memr, NVIDIA_PMC_OFF) & 0x7fff;
 174
 175         if (level  < NVIDIA_BRIGHT_MIN)
 176                 return 0;
 177
 178         level = (level - NVIDIA_BRIGHT_MIN) / NVIDIA_BRIGHT_SCALE;
 179
 180         return (level);
 181 }
 182
 183 static int
 184 nvbl_sysctl(SYSCTL_HANDLER_ARGS)
 185 {
 186         struct nvbl_softc *sc;
 187         int newlevel, error;
 188
 189         sc = arg1;
 190
 191         newlevel = nvbl_getlevel(sc);
 192
 193         error = sysctl_handle_int(oidp, &newlevel, 0, req);
 194
 195         if (error || !req->newptr)
 196                 return (error);
 197
 198         return (nvbl_setlevel(sc, newlevel));
 199 }