1 | /* $NetBSD: linux_i2c.c,v 1.3 2015/03/05 17:29:18 riastradh Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2015 The NetBSD Foundation, Inc. |
5 | * All rights reserved. |
6 | * |
7 | * This code is derived from software contributed to The NetBSD Foundation |
8 | * by Taylor R. Campbell. |
9 | * |
10 | * Redistribution and use in source and binary forms, with or without |
11 | * modification, are permitted provided that the following conditions |
12 | * are met: |
13 | * 1. Redistributions of source code must retain the above copyright |
14 | * notice, this list of conditions and the following disclaimer. |
15 | * 2. Redistributions in binary form must reproduce the above copyright |
16 | * notice, this list of conditions and the following disclaimer in the |
17 | * documentation and/or other materials provided with the distribution. |
18 | * |
19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
29 | * POSSIBILITY OF SUCH DAMAGE. |
30 | */ |
31 | |
32 | #include <sys/cdefs.h> |
33 | __KERNEL_RCSID(0, "$NetBSD: linux_i2c.c,v 1.3 2015/03/05 17:29:18 riastradh Exp $" ); |
34 | |
35 | #include <sys/types.h> |
36 | #include <sys/errno.h> |
37 | #include <sys/kmem.h> |
38 | #include <sys/queue.h> /* XXX include order botch: i2cvar.h needs */ |
39 | |
40 | #include <dev/i2c/i2cvar.h> |
41 | #include <dev/i2c/i2c_bitbang.h> /* XXX include order botch */ |
42 | |
43 | #include <linux/i2c.h> |
44 | #include <linux/i2c-algo-bit.h> |
45 | |
46 | static int netbsd_i2c_transfer(i2c_tag_t, struct i2c_msg *, int); |
47 | static i2c_op_t linux_i2c_flags_op(uint16_t, bool); |
48 | static int linux_i2c_flags_flags(uint16_t); |
49 | static uint32_t linux_i2cbb_functionality(struct i2c_adapter *); |
50 | static int linux_i2cbb_xfer(struct i2c_adapter *, struct i2c_msg *, int); |
51 | static void linux_i2cbb_set_bits(void *, uint32_t); |
52 | static uint32_t linux_i2cbb_read_bits(void *); |
53 | static void linux_i2cbb_set_dir(void *, uint32_t); |
54 | static int linux_i2cbb_send_start(void *, int); |
55 | static int linux_i2cbb_send_stop(void *, int); |
56 | static int linux_i2cbb_initiate_xfer(void *, i2c_addr_t, int); |
57 | static int linux_i2cbb_read_byte(void *, uint8_t *, int); |
58 | static int linux_i2cbb_write_byte(void *, uint8_t, int); |
59 | |
60 | /* |
61 | * Client operations: operations with a particular i2c slave device. |
62 | */ |
63 | |
64 | struct i2c_client * |
65 | i2c_new_device(struct i2c_adapter *adapter, const struct i2c_board_info *info) |
66 | { |
67 | struct i2c_client *client; |
68 | |
69 | client = kmem_alloc(sizeof(*client), KM_SLEEP); |
70 | client->adapter = adapter; |
71 | client->addr = info->addr; |
72 | client->flags = info->flags; |
73 | |
74 | return client; |
75 | } |
76 | |
77 | void |
78 | i2c_unregister_device(struct i2c_client *client) |
79 | { |
80 | |
81 | kmem_free(client, sizeof(*client)); |
82 | } |
83 | |
84 | int |
85 | i2c_master_send(const struct i2c_client *client, const char *buf, int count) |
86 | { |
87 | struct i2c_msg msg = { |
88 | .addr = client->addr, |
89 | .flags = client->flags & I2C_M_TEN, |
90 | .len = count, |
91 | .buf = __UNCONST(buf), |
92 | }; |
93 | int ret; |
94 | |
95 | KASSERT(0 <= count); |
96 | |
97 | ret = i2c_transfer(client->adapter, &msg, 1); |
98 | if (ret <= 0) |
99 | return ret; |
100 | |
101 | return count; |
102 | } |
103 | |
104 | int |
105 | i2c_master_recv(const struct i2c_client *client, char *buf, int count) |
106 | { |
107 | struct i2c_msg msg = { |
108 | .addr = client->addr, |
109 | .flags = (client->flags & I2C_M_TEN) | I2C_M_RD, |
110 | .len = count, |
111 | .buf = buf, |
112 | }; |
113 | int ret; |
114 | |
115 | ret = i2c_transfer(client->adapter, &msg, 1); |
116 | if (ret <= 0) |
117 | return ret; |
118 | |
119 | return count; |
120 | } |
121 | |
122 | /* |
123 | * Adapter operations: operations over an i2c bus via a particular |
124 | * controller. |
125 | */ |
126 | |
127 | int |
128 | i2c_transfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int n) |
129 | { |
130 | |
131 | return (*adapter->algo->master_xfer)(adapter, msgs, n); |
132 | } |
133 | |
134 | static int |
135 | netbsd_i2c_transfer(i2c_tag_t i2c, struct i2c_msg *msgs, int n) |
136 | { |
137 | int i; |
138 | int error; |
139 | |
140 | for (i = 0; i < n; i++) { |
141 | const i2c_op_t op = linux_i2c_flags_op(msgs[i].flags, |
142 | ((i + 1) == n)); |
143 | const int flags = linux_i2c_flags_flags(msgs[i].flags); |
144 | |
145 | switch (op) { |
146 | case I2C_OP_READ: |
147 | case I2C_OP_READ_WITH_STOP: |
148 | error = iic_exec(i2c, op, msgs[i].addr, |
149 | NULL, 0, msgs[i].buf, msgs[i].len, flags); |
150 | break; |
151 | |
152 | case I2C_OP_WRITE: |
153 | case I2C_OP_WRITE_WITH_STOP: |
154 | error = iic_exec(i2c, op, msgs[i].addr, |
155 | msgs[i].buf, msgs[i].len, NULL, 0, flags); |
156 | break; |
157 | |
158 | default: |
159 | error = EINVAL; |
160 | } |
161 | |
162 | if (error) |
163 | /* XXX errno NetBSD->Linux */ |
164 | return -error; |
165 | } |
166 | |
167 | return n; |
168 | } |
169 | |
170 | static i2c_op_t |
171 | linux_i2c_flags_op(uint16_t flags, bool stop) |
172 | { |
173 | |
174 | if (ISSET(flags, I2C_M_RD)) |
175 | return (stop? I2C_OP_READ_WITH_STOP : I2C_OP_READ); |
176 | else |
177 | return (stop? I2C_OP_WRITE_WITH_STOP : I2C_OP_WRITE); |
178 | } |
179 | |
180 | static int |
181 | linux_i2c_flags_flags(uint16_t flags __unused) |
182 | { |
183 | |
184 | return 0; |
185 | } |
186 | |
187 | /* Bit-banging */ |
188 | |
189 | const struct i2c_algorithm i2c_bit_algo = { |
190 | .master_xfer = linux_i2cbb_xfer, |
191 | .functionality = linux_i2cbb_functionality, |
192 | }; |
193 | |
194 | static uint32_t |
195 | linux_i2cbb_functionality(struct i2c_adapter *adapter __unused) |
196 | { |
197 | uint32_t functions = 0; |
198 | |
199 | functions |= I2C_FUNC_I2C; |
200 | functions |= I2C_FUNC_NOSTART; |
201 | functions |= I2C_FUNC_SMBUS_EMUL; |
202 | functions |= I2C_FUNC_SMBUS_READ_BLOCK_DATA; |
203 | functions |= I2C_FUNC_SMBUS_BLOCK_PROC_CALL; |
204 | #if 0 |
205 | functions |= I2C_FUNC_10BIT_ADDR; |
206 | functions |= I2C_FUNC_PROTOCOL_MANGLING; |
207 | #endif |
208 | |
209 | return functions; |
210 | } |
211 | |
212 | static int |
213 | linux_i2cbb_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int n) |
214 | { |
215 | struct i2c_algo_bit_data *const abd = adapter->algo_data; |
216 | struct i2c_controller controller = { |
217 | .ic_cookie = abd, |
218 | .ic_send_start = linux_i2cbb_send_start, |
219 | .ic_send_stop = linux_i2cbb_send_stop, |
220 | .ic_initiate_xfer = linux_i2cbb_initiate_xfer, |
221 | .ic_read_byte = linux_i2cbb_read_byte, |
222 | .ic_write_byte = linux_i2cbb_write_byte, |
223 | }; |
224 | i2c_tag_t i2c = &controller; |
225 | int error; |
226 | |
227 | if (abd->pre_xfer) { |
228 | error = (*abd->pre_xfer)(adapter); |
229 | if (error) |
230 | return error; |
231 | } |
232 | |
233 | error = netbsd_i2c_transfer(i2c, msgs, n); |
234 | |
235 | if (abd->post_xfer) |
236 | (*abd->post_xfer)(adapter); |
237 | |
238 | return error; |
239 | } |
240 | |
241 | #define LI2CBB_SDA 0x01 |
242 | #define LI2CBB_SCL 0x02 |
243 | #define LI2CBB_INPUT 0x04 |
244 | #define LI2CBB_OUTPUT 0x08 |
245 | |
246 | static struct i2c_bitbang_ops linux_i2cbb_ops = { |
247 | .ibo_set_bits = linux_i2cbb_set_bits, |
248 | .ibo_set_dir = linux_i2cbb_set_dir, |
249 | .ibo_read_bits = linux_i2cbb_read_bits, |
250 | .ibo_bits = { |
251 | [I2C_BIT_SDA] = LI2CBB_SDA, |
252 | [I2C_BIT_SCL] = LI2CBB_SCL, |
253 | [I2C_BIT_INPUT] = LI2CBB_INPUT, |
254 | [I2C_BIT_OUTPUT] = LI2CBB_OUTPUT, |
255 | }, |
256 | }; |
257 | |
258 | static void |
259 | linux_i2cbb_set_bits(void *cookie, uint32_t bits) |
260 | { |
261 | struct i2c_algo_bit_data *const abd = cookie; |
262 | |
263 | (*abd->setsda)(abd->data, (ISSET(bits, LI2CBB_SDA)? 1 : 0)); |
264 | (*abd->setscl)(abd->data, (ISSET(bits, LI2CBB_SCL)? 1 : 0)); |
265 | } |
266 | |
267 | static uint32_t |
268 | linux_i2cbb_read_bits(void *cookie) |
269 | { |
270 | struct i2c_algo_bit_data *const abd = cookie; |
271 | uint32_t bits = 0; |
272 | |
273 | if ((*abd->getsda)(abd->data)) |
274 | bits |= LI2CBB_SDA; |
275 | if ((*abd->getscl)(abd->data)) |
276 | bits |= LI2CBB_SCL; |
277 | |
278 | return bits; |
279 | } |
280 | |
281 | static void |
282 | linux_i2cbb_set_dir(void *cookie __unused, uint32_t bits __unused) |
283 | { |
284 | /* Linux doesn't do anything here... */ |
285 | } |
286 | |
287 | static int |
288 | linux_i2cbb_send_start(void *cookie, int flags) |
289 | { |
290 | |
291 | return i2c_bitbang_send_start(cookie, flags, &linux_i2cbb_ops); |
292 | } |
293 | |
294 | static int |
295 | linux_i2cbb_send_stop(void *cookie, int flags) |
296 | { |
297 | |
298 | return i2c_bitbang_send_stop(cookie, flags, &linux_i2cbb_ops); |
299 | } |
300 | |
301 | static int |
302 | linux_i2cbb_initiate_xfer(void *cookie, i2c_addr_t addr, int flags) |
303 | { |
304 | |
305 | return i2c_bitbang_initiate_xfer(cookie, addr, flags, |
306 | &linux_i2cbb_ops); |
307 | } |
308 | |
309 | static int |
310 | linux_i2cbb_read_byte(void *cookie, uint8_t *bytep, int flags) |
311 | { |
312 | |
313 | return i2c_bitbang_read_byte(cookie, bytep, flags, &linux_i2cbb_ops); |
314 | } |
315 | |
316 | static int |
317 | linux_i2cbb_write_byte(void *cookie, uint8_t byte, int flags) |
318 | { |
319 | |
320 | return i2c_bitbang_write_byte(cookie, byte, flags, &linux_i2cbb_ops); |
321 | } |
322 | |