1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * STK1160 driver |
4 | * |
5 | * Copyright (C) 2012 Ezequiel Garcia |
6 | * <elezegarcia--a.t--gmail.com> |
7 | * |
8 | * Based on Easycap driver by R.M. Thomas |
9 | * Copyright (C) 2010 R.M. Thomas |
10 | * <rmthomas--a.t--sciolus.org> |
11 | */ |
12 | |
13 | #include <linux/module.h> |
14 | #include <linux/usb.h> |
15 | #include <linux/i2c.h> |
16 | |
17 | #include "stk1160.h" |
18 | #include "stk1160-reg.h" |
19 | |
20 | static unsigned int i2c_debug; |
21 | module_param(i2c_debug, int, 0644); |
22 | MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]" ); |
23 | |
24 | #define dprintk_i2c(fmt, args...) \ |
25 | do { \ |
26 | if (i2c_debug) \ |
27 | printk(KERN_DEBUG fmt, ##args); \ |
28 | } while (0) |
29 | |
30 | static int stk1160_i2c_busy_wait(struct stk1160 *dev, u8 wait_bit_mask) |
31 | { |
32 | unsigned long end; |
33 | u8 flag; |
34 | |
35 | /* Wait until read/write finish bit is set */ |
36 | end = jiffies + msecs_to_jiffies(STK1160_I2C_TIMEOUT); |
37 | while (time_is_after_jiffies(end)) { |
38 | |
39 | stk1160_read_reg(dev, STK1160_SICTL+1, value: &flag); |
40 | /* read/write done? */ |
41 | if (flag & wait_bit_mask) |
42 | goto done; |
43 | |
44 | usleep_range(min: 10 * USEC_PER_MSEC, max: 20 * USEC_PER_MSEC); |
45 | } |
46 | |
47 | return -ETIMEDOUT; |
48 | |
49 | done: |
50 | return 0; |
51 | } |
52 | |
53 | static int stk1160_i2c_write_reg(struct stk1160 *dev, u8 addr, |
54 | u8 reg, u8 value) |
55 | { |
56 | int rc; |
57 | |
58 | /* Set serial device address */ |
59 | rc = stk1160_write_reg(dev, STK1160_SICTL_SDA, value: addr); |
60 | if (rc < 0) |
61 | return rc; |
62 | |
63 | /* Set i2c device register sub-address */ |
64 | rc = stk1160_write_reg(dev, STK1160_SBUSW_WA, value: reg); |
65 | if (rc < 0) |
66 | return rc; |
67 | |
68 | /* Set i2c device register value */ |
69 | rc = stk1160_write_reg(dev, STK1160_SBUSW_WD, value); |
70 | if (rc < 0) |
71 | return rc; |
72 | |
73 | /* Start write now */ |
74 | rc = stk1160_write_reg(dev, STK1160_SICTL, value: 0x01); |
75 | if (rc < 0) |
76 | return rc; |
77 | |
78 | rc = stk1160_i2c_busy_wait(dev, wait_bit_mask: 0x04); |
79 | if (rc < 0) |
80 | return rc; |
81 | |
82 | return 0; |
83 | } |
84 | |
85 | static int stk1160_i2c_read_reg(struct stk1160 *dev, u8 addr, |
86 | u8 reg, u8 *value) |
87 | { |
88 | int rc; |
89 | |
90 | /* Set serial device address */ |
91 | rc = stk1160_write_reg(dev, STK1160_SICTL_SDA, value: addr); |
92 | if (rc < 0) |
93 | return rc; |
94 | |
95 | /* Set i2c device register sub-address */ |
96 | rc = stk1160_write_reg(dev, STK1160_SBUSR_RA, value: reg); |
97 | if (rc < 0) |
98 | return rc; |
99 | |
100 | /* Start read now */ |
101 | rc = stk1160_write_reg(dev, STK1160_SICTL, value: 0x20); |
102 | if (rc < 0) |
103 | return rc; |
104 | |
105 | rc = stk1160_i2c_busy_wait(dev, wait_bit_mask: 0x01); |
106 | if (rc < 0) |
107 | return rc; |
108 | |
109 | rc = stk1160_read_reg(dev, STK1160_SBUSR_RD, value); |
110 | if (rc < 0) |
111 | return rc; |
112 | |
113 | return 0; |
114 | } |
115 | |
116 | /* |
117 | * stk1160_i2c_check_for_device() |
118 | * check if there is a i2c_device at the supplied address |
119 | */ |
120 | static int stk1160_i2c_check_for_device(struct stk1160 *dev, |
121 | unsigned char addr) |
122 | { |
123 | int rc; |
124 | |
125 | /* Set serial device address */ |
126 | rc = stk1160_write_reg(dev, STK1160_SICTL_SDA, value: addr); |
127 | if (rc < 0) |
128 | return rc; |
129 | |
130 | /* Set device sub-address, we'll chip version reg */ |
131 | rc = stk1160_write_reg(dev, STK1160_SBUSR_RA, value: 0x00); |
132 | if (rc < 0) |
133 | return rc; |
134 | |
135 | /* Start read now */ |
136 | rc = stk1160_write_reg(dev, STK1160_SICTL, value: 0x20); |
137 | if (rc < 0) |
138 | return rc; |
139 | |
140 | rc = stk1160_i2c_busy_wait(dev, wait_bit_mask: 0x01); |
141 | if (rc < 0) |
142 | return -ENODEV; |
143 | |
144 | return 0; |
145 | } |
146 | |
147 | /* |
148 | * stk1160_i2c_xfer() |
149 | * the main i2c transfer function |
150 | */ |
151 | static int stk1160_i2c_xfer(struct i2c_adapter *i2c_adap, |
152 | struct i2c_msg msgs[], int num) |
153 | { |
154 | struct stk1160 *dev = i2c_adap->algo_data; |
155 | int addr, rc, i; |
156 | |
157 | for (i = 0; i < num; i++) { |
158 | addr = msgs[i].addr << 1; |
159 | dprintk_i2c("%s: addr=%x" , __func__, addr); |
160 | |
161 | if (!msgs[i].len) { |
162 | /* no len: check only for device presence */ |
163 | rc = stk1160_i2c_check_for_device(dev, addr); |
164 | if (rc < 0) { |
165 | dprintk_i2c(" no device\n" ); |
166 | return rc; |
167 | } |
168 | |
169 | } else if (msgs[i].flags & I2C_M_RD) { |
170 | /* read request without preceding register selection */ |
171 | dprintk_i2c(" subaddr not selected" ); |
172 | rc = -EOPNOTSUPP; |
173 | goto err; |
174 | |
175 | } else if (i + 1 < num && msgs[i].len <= 2 && |
176 | (msgs[i + 1].flags & I2C_M_RD) && |
177 | msgs[i].addr == msgs[i + 1].addr) { |
178 | |
179 | if (msgs[i].len != 1 || msgs[i + 1].len != 1) { |
180 | dprintk_i2c(" len not supported" ); |
181 | rc = -EOPNOTSUPP; |
182 | goto err; |
183 | } |
184 | |
185 | dprintk_i2c(" subaddr=%x" , msgs[i].buf[0]); |
186 | |
187 | rc = stk1160_i2c_read_reg(dev, addr, reg: msgs[i].buf[0], |
188 | value: msgs[i + 1].buf); |
189 | |
190 | dprintk_i2c(" read=%x" , *msgs[i + 1].buf); |
191 | |
192 | /* consumed two msgs, so we skip one of them */ |
193 | i++; |
194 | |
195 | } else { |
196 | if (msgs[i].len != 2) { |
197 | dprintk_i2c(" len not supported" ); |
198 | rc = -EOPNOTSUPP; |
199 | goto err; |
200 | } |
201 | |
202 | dprintk_i2c(" subaddr=%x write=%x" , |
203 | msgs[i].buf[0], msgs[i].buf[1]); |
204 | |
205 | rc = stk1160_i2c_write_reg(dev, addr, reg: msgs[i].buf[0], |
206 | value: msgs[i].buf[1]); |
207 | } |
208 | |
209 | if (rc < 0) |
210 | goto err; |
211 | dprintk_i2c(" OK\n" ); |
212 | } |
213 | |
214 | return num; |
215 | err: |
216 | dprintk_i2c(" ERROR: %d\n" , rc); |
217 | return num; |
218 | } |
219 | |
220 | /* |
221 | * functionality(), what da heck is this? |
222 | */ |
223 | static u32 functionality(struct i2c_adapter *adap) |
224 | { |
225 | return I2C_FUNC_SMBUS_EMUL; |
226 | } |
227 | |
228 | static const struct i2c_algorithm algo = { |
229 | .master_xfer = stk1160_i2c_xfer, |
230 | .functionality = functionality, |
231 | }; |
232 | |
233 | static const struct i2c_adapter adap_template = { |
234 | .owner = THIS_MODULE, |
235 | .name = "stk1160" , |
236 | .algo = &algo, |
237 | }; |
238 | |
239 | static const struct i2c_client client_template = { |
240 | .name = "stk1160 internal" , |
241 | }; |
242 | |
243 | /* |
244 | * stk1160_i2c_register() |
245 | * register i2c bus |
246 | */ |
247 | int stk1160_i2c_register(struct stk1160 *dev) |
248 | { |
249 | int rc; |
250 | |
251 | dev->i2c_adap = adap_template; |
252 | dev->i2c_adap.dev.parent = dev->dev; |
253 | strscpy(dev->i2c_adap.name, "stk1160" , sizeof(dev->i2c_adap.name)); |
254 | dev->i2c_adap.algo_data = dev; |
255 | |
256 | i2c_set_adapdata(adap: &dev->i2c_adap, data: &dev->v4l2_dev); |
257 | |
258 | rc = i2c_add_adapter(adap: &dev->i2c_adap); |
259 | if (rc < 0) { |
260 | stk1160_err("cannot add i2c adapter (%d)\n" , rc); |
261 | return rc; |
262 | } |
263 | |
264 | dev->i2c_client = client_template; |
265 | dev->i2c_client.adapter = &dev->i2c_adap; |
266 | |
267 | /* Set i2c clock divider device address */ |
268 | stk1160_write_reg(dev, STK1160_SICTL_CD, value: 0x0f); |
269 | |
270 | /* ??? */ |
271 | stk1160_write_reg(dev, STK1160_ASIC + 3, value: 0x00); |
272 | |
273 | return 0; |
274 | } |
275 | |
276 | /* |
277 | * stk1160_i2c_unregister() |
278 | * unregister i2c_bus |
279 | */ |
280 | int stk1160_i2c_unregister(struct stk1160 *dev) |
281 | { |
282 | i2c_del_adapter(adap: &dev->i2c_adap); |
283 | return 0; |
284 | } |
285 | |