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 
29 struct nv04_i2c_bus {
30 	struct nvkm_i2c_bus base;
31 	u8 drive;
32 	u8 sense;
33 };
34 
35 static void
nv04_i2c_bus_drive_scl(struct nvkm_i2c_bus * base,int state)36 nv04_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 
46 static void
nv04_i2c_bus_drive_sda(struct nvkm_i2c_bus * base,int state)47 nv04_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 
57 static int
nv04_i2c_bus_sense_scl(struct nvkm_i2c_bus * base)58 nv04_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 
65 static int
nv04_i2c_bus_sense_sda(struct nvkm_i2c_bus * base)66 nv04_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 
73 static const struct nvkm_i2c_bus_func
74 nv04_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 
82 int
nv04_i2c_bus_new(struct nvkm_i2c_pad * pad,int id,u8 drive,u8 sense,struct nvkm_i2c_bus ** pbus)83 nv04_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