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      1 /*	$NetBSD: nouveau_nvkm_subdev_i2c_busnv04.c,v 1.3 2021/12/18 23:45:40 riastradh Exp $	*/
      2 
      3 /*
      4  * Copyright 2015 Red Hat Inc.
      5  *
      6  * Permission is hereby granted, free of charge, to any person obtaining a
      7  * copy of this software and associated documentation files (the "Software"),
      8  * to deal in the Software without restriction, including without limitation
      9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     10  * and/or sell copies of the Software, and to permit persons to whom the
     11  * Software is furnished to do so, subject to the following conditions:
     12  *
     13  * The above copyright notice and this permission notice shall be included in
     14  * all copies or substantial busions of the Software.
     15  *
     16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     19  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
     20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
     21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
     22  * OTHER DEALINGS IN THE SOFTWARE.
     23  *
     24  * Authors: Ben Skeggs <bskeggs (at) redhat.com>
     25  */
     26 #include <sys/cdefs.h>
     27 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_i2c_busnv04.c,v 1.3 2021/12/18 23:45:40 riastradh Exp $");
     28 
     29 #define nv04_i2c_bus(p) container_of((p), struct nv04_i2c_bus, base)
     30 #include "bus.h"
     31 
     32 #include <subdev/vga.h>
     33 
     34 struct nv04_i2c_bus {
     35 	struct nvkm_i2c_bus base;
     36 	u8 drive;
     37 	u8 sense;
     38 };
     39 
     40 static void
     41 nv04_i2c_bus_drive_scl(struct nvkm_i2c_bus *base, int state)
     42 {
     43 	struct nv04_i2c_bus *bus = nv04_i2c_bus(base);
     44 	struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
     45 	u8 val = nvkm_rdvgac(device, 0, bus->drive);
     46 	if (state) val |= 0x20;
     47 	else	   val &= 0xdf;
     48 	nvkm_wrvgac(device, 0, bus->drive, val | 0x01);
     49 }
     50 
     51 static void
     52 nv04_i2c_bus_drive_sda(struct nvkm_i2c_bus *base, int state)
     53 {
     54 	struct nv04_i2c_bus *bus = nv04_i2c_bus(base);
     55 	struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
     56 	u8 val = nvkm_rdvgac(device, 0, bus->drive);
     57 	if (state) val |= 0x10;
     58 	else	   val &= 0xef;
     59 	nvkm_wrvgac(device, 0, bus->drive, val | 0x01);
     60 }
     61 
     62 static int
     63 nv04_i2c_bus_sense_scl(struct nvkm_i2c_bus *base)
     64 {
     65 	struct nv04_i2c_bus *bus = nv04_i2c_bus(base);
     66 	struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
     67 	return !!(nvkm_rdvgac(device, 0, bus->sense) & 0x04);
     68 }
     69 
     70 static int
     71 nv04_i2c_bus_sense_sda(struct nvkm_i2c_bus *base)
     72 {
     73 	struct nv04_i2c_bus *bus = nv04_i2c_bus(base);
     74 	struct nvkm_device *device = bus->base.pad->i2c->subdev.device;
     75 	return !!(nvkm_rdvgac(device, 0, bus->sense) & 0x08);
     76 }
     77 
     78 static const struct nvkm_i2c_bus_func
     79 nv04_i2c_bus_func = {
     80 	.drive_scl = nv04_i2c_bus_drive_scl,
     81 	.drive_sda = nv04_i2c_bus_drive_sda,
     82 	.sense_scl = nv04_i2c_bus_sense_scl,
     83 	.sense_sda = nv04_i2c_bus_sense_sda,
     84 	.xfer = nvkm_i2c_bit_xfer,
     85 };
     86 
     87 int
     88 nv04_i2c_bus_new(struct nvkm_i2c_pad *pad, int id, u8 drive, u8 sense,
     89 		 struct nvkm_i2c_bus **pbus)
     90 {
     91 	struct nv04_i2c_bus *bus;
     92 
     93 	if (!(bus = kzalloc(sizeof(*bus), GFP_KERNEL)))
     94 		return -ENOMEM;
     95 	*pbus = &bus->base;
     96 
     97 	nvkm_i2c_bus_ctor(&nv04_i2c_bus_func, pad, id, &bus->base);
     98 	bus->drive = drive;
     99 	bus->sense = sense;
    100 	return 0;
    101 }
    102