xref: /dragonfly/sys/dev/drm/radeon/atombios_i2c.c (revision 030b3383)
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 	int r = 0;
54 
55 	memset(&args, 0, sizeof(args));
56 
57 	lockmgr(&rdev->mode_info.atom_context->scratch_mutex, LK_EXCLUSIVE);
58 
59 	base = (unsigned char *)rdev->mode_info.atom_context->scratch;
60 
61 	if (flags & HW_I2C_WRITE) {
62 		if (num > ATOM_MAX_HW_I2C_WRITE) {
63 			DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 3)\n", num);
64 			r = -EINVAL;
65 			goto done;
66 		}
67 		if (buf == NULL)
68 			args.ucRegIndex = 0;
69 		else
70 			args.ucRegIndex = buf[0];
71 		if (num)
72 			num--;
73 		if (num)
74 			memcpy(&out, &buf[1], num);
75 		args.lpI2CDataOut = cpu_to_le16(out);
76 	} else {
77 		if (num > ATOM_MAX_HW_I2C_READ) {
78 			DRM_ERROR("hw i2c: tried to read too many bytes (%d vs 255)\n", num);
79 			r = -EINVAL;
80 			goto done;
81 		}
82 		args.ucRegIndex = 0;
83 		args.lpI2CDataOut = 0;
84 	}
85 
86 	args.ucFlag = flags;
87 	args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
88 	args.ucTransBytes = num;
89 	args.ucSlaveAddr = slave_addr << 1;
90 	args.ucLineNumber = chan->rec.i2c_id;
91 
92 	atom_execute_table_scratch_unlocked(rdev->mode_info.atom_context, index, (uint32_t *)&args);
93 
94 	/* error */
95 	if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
96 		DRM_DEBUG_KMS("hw_i2c error\n");
97 		r = -EIO;
98 		goto done;
99 	}
100 
101 	if (!(flags & HW_I2C_WRITE))
102 		radeon_atom_copy_swap(buf, base, num, false);
103 
104 done:
105 	lockmgr(&rdev->mode_info.atom_context->scratch_mutex, LK_RELEASE);
106 
107 	return r;
108 }
109 
110 static int
111 radeon_atom_hw_i2c_xfer(device_t dev, struct iic_msg *msgs, u_int num)
112 {
113 	struct radeon_i2c_chan *i2c = device_get_softc(dev);
114 	struct iic_msg *p;
115 	int i, remaining, current_count, buffer_offset, max_bytes, ret;
116 	u8 flags;
117 
118 	/* check for bus probe */
119 	p = &msgs[0];
120 	if ((num == 1) && (p->len == 0)) {
121 		ret = radeon_process_i2c_ch(i2c,
122 					    p->slave, HW_I2C_WRITE,
123 					    NULL, 0);
124 		if (ret)
125 			return ret;
126 		else
127 			return (0);
128 	}
129 
130 	for (i = 0; i < num; i++) {
131 		p = &msgs[i];
132 		remaining = p->len;
133 		buffer_offset = 0;
134 		/* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */
135 		if (p->flags & IIC_M_RD) {
136 			max_bytes = ATOM_MAX_HW_I2C_READ;
137 			flags = HW_I2C_READ;
138 		} else {
139 			max_bytes = ATOM_MAX_HW_I2C_WRITE;
140 			flags = HW_I2C_WRITE;
141 		}
142 		while (remaining) {
143 			if (remaining > max_bytes)
144 				current_count = max_bytes;
145 			else
146 				current_count = remaining;
147 			ret = radeon_process_i2c_ch(i2c,
148 						    p->slave, flags,
149 						    &p->buf[buffer_offset], current_count);
150 			if (ret)
151 				return ret;
152 			remaining -= current_count;
153 			buffer_offset += current_count;
154 		}
155 	}
156 
157 	return (0);
158 }
159 
160 static int
161 radeon_atom_hw_i2c_probe(device_t dev)
162 {
163 
164 	return (BUS_PROBE_SPECIFIC);
165 }
166 
167 static int
168 radeon_atom_hw_i2c_attach(device_t dev)
169 {
170 	struct radeon_i2c_chan *i2c;
171 	device_t iic_dev;
172 
173 	i2c = device_get_softc(dev);
174 	device_set_desc(dev, i2c->name);
175 
176 	/* add generic bit-banging code */
177 	iic_dev = device_add_child(dev, "iicbus", -1);
178 	if (iic_dev == NULL)
179 		return (ENXIO);
180 	device_quiet(iic_dev);
181 
182 	/* attach and probe added child */
183 	bus_generic_attach(dev);
184 
185 	return (0);
186 }
187 
188 static int
189 radeon_atom_hw_i2c_detach(device_t dev)
190 {
191 	/* detach bit-banding code. */
192 	bus_generic_detach(dev);
193 
194 	/* delete bit-banding code. */
195 	device_delete_children(dev);
196 	return (0);
197 }
198 
199 static int
200 radeon_atom_hw_i2c_reset(device_t dev, u_char speed,
201     u_char addr, u_char *oldaddr)
202 {
203 
204 	return (0);
205 }
206 
207 static device_method_t radeon_atom_hw_i2c_methods[] = {
208 	DEVMETHOD(device_probe,		radeon_atom_hw_i2c_probe),
209 	DEVMETHOD(device_attach,	radeon_atom_hw_i2c_attach),
210 	DEVMETHOD(device_detach,	radeon_atom_hw_i2c_detach),
211 	DEVMETHOD(iicbus_reset,		radeon_atom_hw_i2c_reset),
212 	DEVMETHOD(iicbus_transfer,	radeon_atom_hw_i2c_xfer),
213 	DEVMETHOD_END
214 };
215 
216 static driver_t radeon_atom_hw_i2c_driver = {
217 	"radeon_atom_hw_i2c",
218 	radeon_atom_hw_i2c_methods,
219 	0
220 };
221 
222 static devclass_t radeon_atom_hw_i2c_devclass;
223 DRIVER_MODULE_ORDERED(radeon_atom_hw_i2c, drm, radeon_atom_hw_i2c_driver,
224     radeon_atom_hw_i2c_devclass, NULL, NULL, SI_ORDER_ANY);
225