xref: /linux/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/busnv50.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
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 
29 struct nv50_i2c_bus {
30 	struct nvkm_i2c_bus base;
31 	u32 addr;
32 	u32 data;
33 };
34 
35 static void
36 nv50_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 
45 static void
46 nv50_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 
55 static int
56 nv50_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 
63 static int
64 nv50_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 
71 static void
72 nv50_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 
79 static const struct nvkm_i2c_bus_func
80 nv50_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 
89 int
90 nv50_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