xref: /dragonfly/sys/dev/drm/radeon/atombios_i2c.c (revision 476c884a)
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 int radeon_atom_hw_i2c_xfer(device_t dev, struct iic_msg *msgs, u_int num);
44 
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 = cpu_to_le16(0);
55 	int r = 0;
56 
57 	memset(&args, 0, sizeof(args));
58 
59 	mutex_lock(&chan->mutex);
60 	mutex_lock(&rdev->mode_info.atom_context->scratch_mutex);
61 
62 	base = (unsigned char *)rdev->mode_info.atom_context->scratch;
63 
64 	if (flags & HW_I2C_WRITE) {
65 		if (num > ATOM_MAX_HW_I2C_WRITE) {
66 			DRM_ERROR("hw i2c: tried to write too many bytes (%d vs 3)\n", num);
67 			r = -EINVAL;
68 			goto done;
69 		}
70 		if (buf == NULL)
71 			args.ucRegIndex = 0;
72 		else
73 			args.ucRegIndex = buf[0];
74 		if (num)
75 			num--;
76 		if (num)
77 			memcpy(&out, &buf[1], num);
78 		args.lpI2CDataOut = cpu_to_le16(out);
79 	} else {
80 		if (num > ATOM_MAX_HW_I2C_READ) {
81 			DRM_ERROR("hw i2c: tried to read too many bytes (%d vs 255)\n", num);
82 			r = -EINVAL;
83 			goto done;
84 		}
85 		args.ucRegIndex = 0;
86 		args.lpI2CDataOut = 0;
87 	}
88 
89 	args.ucFlag = flags;
90 	args.ucI2CSpeed = TARGET_HW_I2C_CLOCK;
91 	args.ucTransBytes = num;
92 	args.ucSlaveAddr = slave_addr << 1;
93 	args.ucLineNumber = chan->rec.i2c_id;
94 
95 	atom_execute_table_scratch_unlocked(rdev->mode_info.atom_context, index, (uint32_t *)&args);
96 
97 	/* error */
98 	if (args.ucStatus != HW_ASSISTED_I2C_STATUS_SUCCESS) {
99 		DRM_DEBUG_KMS("hw_i2c error\n");
100 		r = -EIO;
101 		goto done;
102 	}
103 
104 	if (!(flags & HW_I2C_WRITE))
105 		radeon_atom_copy_swap(buf, base, num, false);
106 
107 done:
108 	mutex_unlock(&rdev->mode_info.atom_context->scratch_mutex);
109 	mutex_unlock(&chan->mutex);
110 
111 	return r;
112 }
113 
114 int radeon_atom_hw_i2c_xfer(device_t dev, struct iic_msg *msgs, u_int num)
115 {
116 	struct radeon_i2c_chan *i2c = device_get_softc(dev);
117 	struct iic_msg *p;
118 	int i, remaining, current_count, buffer_offset, max_bytes, ret;
119 	u8 flags;
120 
121 	/* check for bus probe */
122 	p = &msgs[0];
123 	if ((num == 1) && (p->len == 0)) {
124 		ret = radeon_process_i2c_ch(i2c,
125 					    p->slave, HW_I2C_WRITE,
126 					    NULL, 0);
127 		if (ret)
128 			return ret;
129 		else
130 			return (0);
131 	}
132 
133 	for (i = 0; i < num; i++) {
134 		p = &msgs[i];
135 		remaining = p->len;
136 		buffer_offset = 0;
137 		/* max_bytes are a limitation of ProcessI2cChannelTransaction not the hw */
138 		if (p->flags & IIC_M_RD) {
139 			max_bytes = ATOM_MAX_HW_I2C_READ;
140 			flags = HW_I2C_READ;
141 		} else {
142 			max_bytes = ATOM_MAX_HW_I2C_WRITE;
143 			flags = HW_I2C_WRITE;
144 		}
145 		while (remaining) {
146 			if (remaining > max_bytes)
147 				current_count = max_bytes;
148 			else
149 				current_count = remaining;
150 			ret = radeon_process_i2c_ch(i2c,
151 						    p->slave, flags,
152 						    &p->buf[buffer_offset], current_count);
153 			if (ret)
154 				return ret;
155 			remaining -= current_count;
156 			buffer_offset += current_count;
157 		}
158 	}
159 
160 	return (0);
161 }
162 
163 static int
164 radeon_atom_hw_i2c_probe(device_t dev)
165 {
166 
167 	return (BUS_PROBE_SPECIFIC);
168 }
169 
170 static int
171 radeon_atom_hw_i2c_attach(device_t dev)
172 {
173 	struct radeon_i2c_chan *i2c;
174 	device_t iic_dev;
175 
176 	i2c = device_get_softc(dev);
177 	device_set_desc(dev, i2c->name);
178 
179 	/* add generic bit-banging code */
180 	iic_dev = device_add_child(dev, "iicbus", -1);
181 	if (iic_dev == NULL)
182 		return (ENXIO);
183 	device_quiet(iic_dev);
184 
185 	/* attach and probe added child */
186 	bus_generic_attach(dev);
187 
188 	return (0);
189 }
190 
191 static int
192 radeon_atom_hw_i2c_detach(device_t dev)
193 {
194 	/* detach bit-banding code. */
195 	bus_generic_detach(dev);
196 
197 	/* delete bit-banding code. */
198 	device_delete_children(dev);
199 	return (0);
200 }
201 
202 static int
203 radeon_atom_hw_i2c_reset(device_t dev, u_char speed,
204     u_char addr, u_char *oldaddr)
205 {
206 
207 	return (0);
208 }
209 
210 static device_method_t radeon_atom_hw_i2c_methods[] = {
211 	DEVMETHOD(device_probe,		radeon_atom_hw_i2c_probe),
212 	DEVMETHOD(device_attach,	radeon_atom_hw_i2c_attach),
213 	DEVMETHOD(device_detach,	radeon_atom_hw_i2c_detach),
214 	DEVMETHOD(iicbus_reset,		radeon_atom_hw_i2c_reset),
215 	DEVMETHOD(iicbus_transfer,	radeon_atom_hw_i2c_xfer),
216 	DEVMETHOD_END
217 };
218 
219 static driver_t radeon_atom_hw_i2c_driver = {
220 	"radeon_atom_hw_i2c",
221 	radeon_atom_hw_i2c_methods,
222 	0
223 };
224 
225 static devclass_t radeon_atom_hw_i2c_devclass;
226 DRIVER_MODULE_ORDERED(radeon_atom_hw_i2c, drm, radeon_atom_hw_i2c_driver,
227     radeon_atom_hw_i2c_devclass, NULL, NULL, SI_ORDER_ANY);
228