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  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD: stable/9/sys/dev/drm2/radeon/atombios_i2c.c 254885 2013-08-25 19:37:15Z dumbbell $");
28 
29 #include <dev/drm2/drmP.h>
30 #include <dev/drm2/radeon/radeon_drm.h>
31 #include <dev/iicbus/iic.h>
32 #include <dev/iicbus/iiconf.h>
33 #include <dev/iicbus/iicbus.h>
34 #include "radeon.h"
35 #include "atom.h"
36 #include "iicbus_if.h"
37 #include "iicbb_if.h"
38 
39 #define TARGET_HW_I2C_CLOCK 50
40 
41 /* these are a limitation of ProcessI2cChannelTransaction not the hw */
42 #define ATOM_MAX_HW_I2C_WRITE 2
43 #define ATOM_MAX_HW_I2C_READ  255
44 
radeon_process_i2c_ch(struct radeon_i2c_chan * chan,u8 slave_addr,u8 flags,u8 * buf,u8 num)45 static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan,
46 				 u8 slave_addr, u8 flags,
47 				 u8 *buf, u8 num)
48 {
49 	struct drm_device *dev = chan->dev;
50 	struct radeon_device *rdev = dev->dev_private;
51 	PROCESS_I2C_CHANNEL_TRANSACTION_PS_ALLOCATION args;
52 	int index = GetIndexIntoMasterTable(COMMAND, ProcessI2cChannelTransaction);
53 	unsigned char *base;
54 	u16 out;
55 
56 	memset(&args, 0, sizeof(args));
57 
58 	base = (unsigned char *)rdev->mode_info.atom_context->scratch;
59 
60 	if (flags & HW_I2C_WRITE) {
61 		if (num > ATOM_MAX_HW_I2C_WRITE) {
62 			DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 2)\n", num);
63 			return EINVAL;
64 		}
65 		memcpy(&out, buf, num);
66 		args.lpI2CDataOut = cpu_to_le16(out);
67 	}
68 
69 	args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
70 	args.ucRegIndex = 0;
71 	args.ucTransBytes = num;
72 	args.ucSlaveAddr = slave_addr << 1;
73 	args.ucLineNumber = chan->rec.i2c_id;
74 
75 	atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
76 
77 	/* error */
78 	if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
79 		DRM_DEBUG_KMS("hw_i2c error\n");
80 		return EIO;
81 	}
82 
83 	if (!(flags & HW_I2C_WRITE))
84 		memcpy(buf, base, num);
85 
86 	return 0;
87 }
88 
89 static int
radeon_atom_hw_i2c_xfer(device_t dev,struct iic_msg * msgs,u_int num)90 radeon_atom_hw_i2c_xfer(device_t dev, struct iic_msg *msgs, u_int num)
91 {
92 	struct radeon_i2c_chan *i2c = device_get_softc(dev);
93 	struct iic_msg *p;
94 	int i, remaining, current_count, buffer_offset, max_bytes, ret;
95 	u8 buf = 0, flags;
96 
97 	/* check for bus probe */
98 	p = &msgs[0];
99 	if ((num == 1) && (p->len == 0)) {
100 		ret = radeon_process_i2c_ch(i2c,
101 					    p->slave, HW_I2C_WRITE,
102 					    &buf, 1);
103 		if (ret)
104 			return ret;
105 		else
106 			return (0);
107 	}
108 
109 	for (i = 0; i < num; i++) {
110 		p = &msgs[i];
111 		remaining = p->len;
112 		buffer_offset = 0;
113 		/* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */
114 		if (p->flags & IIC_M_RD) {
115 			max_bytes = ATOM_MAX_HW_I2C_READ;
116 			flags = HW_I2C_READ;
117 		} else {
118 			max_bytes = ATOM_MAX_HW_I2C_WRITE;
119 			flags = HW_I2C_WRITE;
120 		}
121 		while (remaining) {
122 			if (remaining > max_bytes)
123 				current_count = max_bytes;
124 			else
125 				current_count = remaining;
126 			ret = radeon_process_i2c_ch(i2c,
127 						    p->slave, flags,
128 						    &p->buf[buffer_offset], current_count);
129 			if (ret)
130 				return ret;
131 			remaining -= current_count;
132 			buffer_offset += current_count;
133 		}
134 	}
135 
136 	return (0);
137 }
138 
139 static int
radeon_atom_hw_i2c_probe(device_t dev)140 radeon_atom_hw_i2c_probe(device_t dev)
141 {
142 
143 	return (BUS_PROBE_SPECIFIC);
144 }
145 
146 static int
radeon_atom_hw_i2c_attach(device_t dev)147 radeon_atom_hw_i2c_attach(device_t dev)
148 {
149 	struct radeon_i2c_chan *i2c;
150 	device_t iic_dev;
151 
152 	i2c = device_get_softc(dev);
153 	device_set_desc(dev, i2c->name);
154 
155 	/* add generic bit-banging code */
156 	iic_dev = device_add_child(dev, "iicbus", -1);
157 	if (iic_dev == NULL)
158 		return (ENXIO);
159 	device_quiet(iic_dev);
160 
161 	/* attach and probe added child */
162 	bus_generic_attach(dev);
163 
164 	return (0);
165 }
166 
167 static int
radeon_atom_hw_i2c_detach(device_t dev)168 radeon_atom_hw_i2c_detach(device_t dev)
169 {
170 	/* detach bit-banding code. */
171 	bus_generic_detach(dev);
172 
173 	/* delete bit-banding code. */
174 	device_delete_children(dev);
175 	return (0);
176 }
177 
178 static int
radeon_atom_hw_i2c_reset(device_t dev,u_char speed,u_char addr,u_char * oldaddr)179 radeon_atom_hw_i2c_reset(device_t dev, u_char speed,
180     u_char addr, u_char *oldaddr)
181 {
182 
183 	return (0);
184 }
185 
186 static device_method_t radeon_atom_hw_i2c_methods[] = {
187 	DEVMETHOD(device_probe,		radeon_atom_hw_i2c_probe),
188 	DEVMETHOD(device_attach,	radeon_atom_hw_i2c_attach),
189 	DEVMETHOD(device_detach,	radeon_atom_hw_i2c_detach),
190 	DEVMETHOD(iicbus_reset,		radeon_atom_hw_i2c_reset),
191 	DEVMETHOD(iicbus_transfer,	radeon_atom_hw_i2c_xfer),
192 	DEVMETHOD_END
193 };
194 
195 static driver_t radeon_atom_hw_i2c_driver = {
196 	"radeon_atom_hw_i2c",
197 	radeon_atom_hw_i2c_methods,
198 	0
199 };
200 
201 static devclass_t radeon_atom_hw_i2c_devclass;
202 DRIVER_MODULE_ORDERED(radeon_atom_hw_i2c, drmn, radeon_atom_hw_i2c_driver,
203     radeon_atom_hw_i2c_devclass, 0, 0, SI_ORDER_ANY);
204