xref: /dragonfly/sys/dev/drm/radeon/atombios_i2c.c (revision cf89a63b)
1 /*
2  * Copyright 2011 Advanced Micro Devices, 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 portions 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: Alex Deucher
23  *
24  * $FreeBSD: head/sys/dev/drm2/radeon/atombios_i2c.c 254885 2013-08-25 19:37:15Z dumbbell $
25  */
26 
27 #include <drm/drmP.h>
28 #include <uapi_drm/radeon_drm.h>
29 #include <bus/iicbus/iic.h>
30 #include <bus/iicbus/iiconf.h>
31 #include <bus/iicbus/iicbus.h>
32 #include "radeon.h"
33 #include "atom.h"
34 #include "iicbus_if.h"
35 #include "iicbb_if.h"
36 
37 #define TARGET_HW_I2C_CLOCK 50
38 
39 /* these are a limitation of ProcessI2cChannelTransaction not the hw */
40 #define ATOM_MAX_HW_I2C_WRITE 2
41 #define ATOM_MAX_HW_I2C_READ  255
42 
43 static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan,
44 				 u8 slave_addr, u8 flags,
45 				 u8 *buf, u8 num)
46 {
47 	struct drm_device *dev = chan->dev;
48 	struct radeon_device *rdev = dev->dev_private;
49 	PROCESS_I2C_CHANNEL_TRANSACTION_PS_ALLOCATION args;
50 	int index = GetIndexIntoMasterTable(COMMAND, ProcessI2cChannelTransaction);
51 	unsigned char *base;
52 	u16 out;
53 
54 	memset(&args, 0, sizeof(args));
55 
56 	base = (unsigned char *)rdev->mode_info.atom_context->scratch;
57 
58 	if (flags & HW_I2C_WRITE) {
59 		if (num > ATOM_MAX_HW_I2C_WRITE) {
60 			DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 2)\n", num);
61 			return EINVAL;
62 		}
63 		memcpy(&out, buf, num);
64 		args.lpI2CDataOut = cpu_to_le16(out);
65 	}
66 
67 	args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
68 	args.ucRegIndex = 0;
69 	args.ucTransBytes = num;
70 	args.ucSlaveAddr = slave_addr << 1;
71 	args.ucLineNumber = chan->rec.i2c_id;
72 
73 	atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
74 
75 	/* error */
76 	if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
77 		DRM_DEBUG_KMS("hw_i2c error\n");
78 		return EIO;
79 	}
80 
81 	if (!(flags & HW_I2C_WRITE))
82 		memcpy(buf, base, num);
83 
84 	return 0;
85 }
86 
87 static int
88 radeon_atom_hw_i2c_xfer(device_t dev, struct iic_msg *msgs, u_int num)
89 {
90 	struct radeon_i2c_chan *i2c = device_get_softc(dev);
91 	struct iic_msg *p;
92 	int i, remaining, current_count, buffer_offset, max_bytes, ret;
93 	u8 buf = 0, flags;
94 
95 	/* check for bus probe */
96 	p = &msgs[0];
97 	if ((num == 1) && (p->len == 0)) {
98 		ret = radeon_process_i2c_ch(i2c,
99 					    p->slave, HW_I2C_WRITE,
100 					    &buf, 1);
101 		if (ret)
102 			return ret;
103 		else
104 			return (0);
105 	}
106 
107 	for (i = 0; i < num; i++) {
108 		p = &msgs[i];
109 		remaining = p->len;
110 		buffer_offset = 0;
111 		/* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */
112 		if (p->flags & IIC_M_RD) {
113 			max_bytes = ATOM_MAX_HW_I2C_READ;
114 			flags = HW_I2C_READ;
115 		} else {
116 			max_bytes = ATOM_MAX_HW_I2C_WRITE;
117 			flags = HW_I2C_WRITE;
118 		}
119 		while (remaining) {
120 			if (remaining > max_bytes)
121 				current_count = max_bytes;
122 			else
123 				current_count = remaining;
124 			ret = radeon_process_i2c_ch(i2c,
125 						    p->slave, flags,
126 						    &p->buf[buffer_offset], current_count);
127 			if (ret)
128 				return ret;
129 			remaining -= current_count;
130 			buffer_offset += current_count;
131 		}
132 	}
133 
134 	return (0);
135 }
136 
137 static int
138 radeon_atom_hw_i2c_probe(device_t dev)
139 {
140 
141 	return (BUS_PROBE_SPECIFIC);
142 }
143 
144 static int
145 radeon_atom_hw_i2c_attach(device_t dev)
146 {
147 	struct radeon_i2c_chan *i2c;
148 	device_t iic_dev;
149 
150 	i2c = device_get_softc(dev);
151 	device_set_desc(dev, i2c->name);
152 
153 	/* add generic bit-banging code */
154 	iic_dev = device_add_child(dev, "iicbus", -1);
155 	if (iic_dev == NULL)
156 		return (ENXIO);
157 	device_quiet(iic_dev);
158 
159 	/* attach and probe added child */
160 	bus_generic_attach(dev);
161 
162 	return (0);
163 }
164 
165 static int
166 radeon_atom_hw_i2c_detach(device_t dev)
167 {
168 	/* detach bit-banding code. */
169 	bus_generic_detach(dev);
170 
171 	/* delete bit-banding code. */
172 	device_delete_children(dev);
173 	return (0);
174 }
175 
176 static int
177 radeon_atom_hw_i2c_reset(device_t dev, u_char speed,
178     u_char addr, u_char *oldaddr)
179 {
180 
181 	return (0);
182 }
183 
184 static device_method_t radeon_atom_hw_i2c_methods[] = {
185 	DEVMETHOD(device_probe,		radeon_atom_hw_i2c_probe),
186 	DEVMETHOD(device_attach,	radeon_atom_hw_i2c_attach),
187 	DEVMETHOD(device_detach,	radeon_atom_hw_i2c_detach),
188 	DEVMETHOD(iicbus_reset,		radeon_atom_hw_i2c_reset),
189 	DEVMETHOD(iicbus_transfer,	radeon_atom_hw_i2c_xfer),
190 	DEVMETHOD_END
191 };
192 
193 static driver_t radeon_atom_hw_i2c_driver = {
194 	"radeon_atom_hw_i2c",
195 	radeon_atom_hw_i2c_methods,
196 	0
197 };
198 
199 static devclass_t radeon_atom_hw_i2c_devclass;
200 DRIVER_MODULE_ORDERED(radeon_atom_hw_i2c, drm, radeon_atom_hw_i2c_driver,
201     radeon_atom_hw_i2c_devclass, 0, 0, SI_ORDER_ANY);
202