xref: /dragonfly/sys/dev/drm/radeon/atombios_i2c.c (revision 279dd846)
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 3
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 = cpu_to_le16(0);
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 3)\n", num);
61 			return EINVAL;
62 		}
63 		if (buf == NULL)
64 			args.ucRegIndex = 0;
65 		else
66 			args.ucRegIndex = buf[0];
67 		if (num)
68 			num--;
69 		if (num)
70 			memcpy(&out, &buf[1], num);
71 		args.lpI2CDataOut = cpu_to_le16(out);
72 	} else {
73 		if (num > ATOM_MAX_HW_I2C_READ) {
74 			DRM_ERROR("hw i2c: tried to read too many bytes (%d vs 255)\n", num);
75 			return -EINVAL;
76 		}
77 		args.ucRegIndex = 0;
78 		args.lpI2CDataOut = 0;
79 	}
80 
81 	args.ucFlag = flags;
82 	args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
83 	args.ucTransBytes = num;
84 	args.ucSlaveAddr = slave_addr << 1;
85 	args.ucLineNumber = chan->rec.i2c_id;
86 
87 	atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
88 
89 	/* error */
90 	if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
91 		DRM_DEBUG_KMS("hw_i2c error\n");
92 		return EIO;
93 	}
94 
95 	if (!(flags & HW_I2C_WRITE))
96 		radeon_atom_copy_swap(buf, base, num, false);
97 
98 	return 0;
99 }
100 
101 static int
102 radeon_atom_hw_i2c_xfer(device_t dev, struct iic_msg *msgs, u_int num)
103 {
104 	struct radeon_i2c_chan *i2c = device_get_softc(dev);
105 	struct iic_msg *p;
106 	int i, remaining, current_count, buffer_offset, max_bytes, ret;
107 	u8 flags;
108 
109 	/* check for bus probe */
110 	p = &msgs[0];
111 	if ((num == 1) && (p->len == 0)) {
112 		ret = radeon_process_i2c_ch(i2c,
113 					    p->slave, HW_I2C_WRITE,
114 					    NULL, 0);
115 		if (ret)
116 			return ret;
117 		else
118 			return (0);
119 	}
120 
121 	for (i = 0; i < num; i++) {
122 		p = &msgs[i];
123 		remaining = p->len;
124 		buffer_offset = 0;
125 		/* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */
126 		if (p->flags & IIC_M_RD) {
127 			max_bytes = ATOM_MAX_HW_I2C_READ;
128 			flags = HW_I2C_READ;
129 		} else {
130 			max_bytes = ATOM_MAX_HW_I2C_WRITE;
131 			flags = HW_I2C_WRITE;
132 		}
133 		while (remaining) {
134 			if (remaining > max_bytes)
135 				current_count = max_bytes;
136 			else
137 				current_count = remaining;
138 			ret = radeon_process_i2c_ch(i2c,
139 						    p->slave, flags,
140 						    &p->buf[buffer_offset], current_count);
141 			if (ret)
142 				return ret;
143 			remaining -= current_count;
144 			buffer_offset += current_count;
145 		}
146 	}
147 
148 	return (0);
149 }
150 
151 static int
152 radeon_atom_hw_i2c_probe(device_t dev)
153 {
154 
155 	return (BUS_PROBE_SPECIFIC);
156 }
157 
158 static int
159 radeon_atom_hw_i2c_attach(device_t dev)
160 {
161 	struct radeon_i2c_chan *i2c;
162 	device_t iic_dev;
163 
164 	i2c = device_get_softc(dev);
165 	device_set_desc(dev, i2c->name);
166 
167 	/* add generic bit-banging code */
168 	iic_dev = device_add_child(dev, "iicbus", -1);
169 	if (iic_dev == NULL)
170 		return (ENXIO);
171 	device_quiet(iic_dev);
172 
173 	/* attach and probe added child */
174 	bus_generic_attach(dev);
175 
176 	return (0);
177 }
178 
179 static int
180 radeon_atom_hw_i2c_detach(device_t dev)
181 {
182 	/* detach bit-banding code. */
183 	bus_generic_detach(dev);
184 
185 	/* delete bit-banding code. */
186 	device_delete_children(dev);
187 	return (0);
188 }
189 
190 static int
191 radeon_atom_hw_i2c_reset(device_t dev, u_char speed,
192     u_char addr, u_char *oldaddr)
193 {
194 
195 	return (0);
196 }
197 
198 static device_method_t radeon_atom_hw_i2c_methods[] = {
199 	DEVMETHOD(device_probe,		radeon_atom_hw_i2c_probe),
200 	DEVMETHOD(device_attach,	radeon_atom_hw_i2c_attach),
201 	DEVMETHOD(device_detach,	radeon_atom_hw_i2c_detach),
202 	DEVMETHOD(iicbus_reset,		radeon_atom_hw_i2c_reset),
203 	DEVMETHOD(iicbus_transfer,	radeon_atom_hw_i2c_xfer),
204 	DEVMETHOD_END
205 };
206 
207 static driver_t radeon_atom_hw_i2c_driver = {
208 	"radeon_atom_hw_i2c",
209 	radeon_atom_hw_i2c_methods,
210 	0
211 };
212 
213 static devclass_t radeon_atom_hw_i2c_devclass;
214 DRIVER_MODULE_ORDERED(radeon_atom_hw_i2c, drm, radeon_atom_hw_i2c_driver,
215     radeon_atom_hw_i2c_devclass, NULL, NULL, SI_ORDER_ANY);
216