Commit | Line | Data |
---|---|---|
ccfc97bd SA |
1 | /* |
2 | * drivers/media/video/smiapp/smiapp-regs.c | |
3 | * | |
4 | * Generic driver for SMIA/SMIA++ compliant camera modules | |
5 | * | |
6 | * Copyright (C) 2011--2012 Nokia Corporation | |
7 | * Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * version 2 as published by the Free Software Foundation. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, but | |
14 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA | |
21 | * 02110-1301 USA | |
22 | * | |
23 | */ | |
24 | ||
ccfc97bd SA |
25 | #include <linux/delay.h> |
26 | #include <linux/i2c.h> | |
27 | ||
28 | #include "smiapp-regs.h" | |
29 | ||
30 | static uint32_t float_to_u32_mul_1000000(struct i2c_client *client, | |
31 | uint32_t phloat) | |
32 | { | |
33 | int32_t exp; | |
34 | uint64_t man; | |
35 | ||
36 | if (phloat >= 0x80000000) { | |
37 | dev_err(&client->dev, "this is a negative number\n"); | |
38 | return 0; | |
39 | } | |
40 | ||
41 | if (phloat == 0x7f800000) | |
42 | return ~0; /* Inf. */ | |
43 | ||
44 | if ((phloat & 0x7f800000) == 0x7f800000) { | |
45 | dev_err(&client->dev, "NaN or other special number\n"); | |
46 | return 0; | |
47 | } | |
48 | ||
49 | /* Valid cases begin here */ | |
50 | if (phloat == 0) | |
51 | return 0; /* Valid zero */ | |
52 | ||
53 | if (phloat > 0x4f800000) | |
54 | return ~0; /* larger than 4294967295 */ | |
55 | ||
56 | /* | |
57 | * Unbias exponent (note how phloat is now guaranteed to | |
58 | * have 0 in the high bit) | |
59 | */ | |
60 | exp = ((int32_t)phloat >> 23) - 127; | |
61 | ||
62 | /* Extract mantissa, add missing '1' bit and it's in MHz */ | |
63 | man = ((phloat & 0x7fffff) | 0x800000) * 1000000ULL; | |
64 | ||
65 | if (exp < 0) | |
66 | man >>= -exp; | |
67 | else | |
68 | man <<= exp; | |
69 | ||
70 | man >>= 23; /* Remove mantissa bias */ | |
71 | ||
72 | return man & 0xffffffff; | |
73 | } | |
74 | ||
75 | ||
76 | /* | |
77 | * Read a 8/16/32-bit i2c register. The value is returned in 'val'. | |
78 | * Returns zero if successful, or non-zero otherwise. | |
79 | */ | |
80 | int smiapp_read(struct i2c_client *client, u32 reg, u32 *val) | |
81 | { | |
82 | struct i2c_msg msg; | |
83 | unsigned char data[4]; | |
84 | unsigned int len = (u8)(reg >> 16); | |
85 | u16 offset = reg; | |
86 | int r; | |
87 | ||
88 | if (len != SMIA_REG_8BIT && len != SMIA_REG_16BIT | |
89 | && len != SMIA_REG_32BIT) | |
90 | return -EINVAL; | |
91 | ||
92 | msg.addr = client->addr; | |
93 | msg.flags = 0; | |
94 | msg.len = 2; | |
95 | msg.buf = data; | |
96 | ||
97 | /* high byte goes out first */ | |
98 | data[0] = (u8) (offset >> 8); | |
99 | data[1] = (u8) offset; | |
100 | r = i2c_transfer(client->adapter, &msg, 1); | |
101 | if (r != 1) { | |
102 | if (r >= 0) | |
103 | r = -EBUSY; | |
104 | goto err; | |
105 | } | |
106 | ||
107 | msg.len = len; | |
108 | msg.flags = I2C_M_RD; | |
109 | r = i2c_transfer(client->adapter, &msg, 1); | |
110 | if (r != 1) { | |
111 | if (r >= 0) | |
112 | r = -EBUSY; | |
113 | goto err; | |
114 | } | |
115 | ||
116 | *val = 0; | |
117 | /* high byte comes first */ | |
118 | switch (len) { | |
119 | case SMIA_REG_32BIT: | |
120 | *val = (data[0] << 24) + (data[1] << 16) + (data[2] << 8) + | |
121 | data[3]; | |
122 | break; | |
123 | case SMIA_REG_16BIT: | |
124 | *val = (data[0] << 8) + data[1]; | |
125 | break; | |
126 | case SMIA_REG_8BIT: | |
127 | *val = data[0]; | |
128 | break; | |
129 | default: | |
130 | BUG(); | |
131 | } | |
132 | ||
133 | if (reg & SMIA_REG_FLAG_FLOAT) | |
134 | *val = float_to_u32_mul_1000000(client, *val); | |
135 | ||
136 | return 0; | |
137 | ||
138 | err: | |
139 | dev_err(&client->dev, "read from offset 0x%x error %d\n", offset, r); | |
140 | ||
141 | return r; | |
142 | } | |
143 | ||
144 | /* | |
145 | * Write to a 8/16-bit register. | |
146 | * Returns zero if successful, or non-zero otherwise. | |
147 | */ | |
148 | int smiapp_write(struct i2c_client *client, u32 reg, u32 val) | |
149 | { | |
150 | struct i2c_msg msg; | |
151 | unsigned char data[6]; | |
152 | unsigned int retries; | |
153 | unsigned int flags = reg >> 24; | |
154 | unsigned int len = (u8)(reg >> 16); | |
155 | u16 offset = reg; | |
156 | int r; | |
157 | ||
158 | if ((len != SMIA_REG_8BIT && len != SMIA_REG_16BIT && | |
159 | len != SMIA_REG_32BIT) || flags) | |
160 | return -EINVAL; | |
161 | ||
162 | msg.addr = client->addr; | |
163 | msg.flags = 0; /* Write */ | |
164 | msg.len = 2 + len; | |
165 | msg.buf = data; | |
166 | ||
167 | /* high byte goes out first */ | |
168 | data[0] = (u8) (reg >> 8); | |
169 | data[1] = (u8) (reg & 0xff); | |
170 | ||
171 | switch (len) { | |
172 | case SMIA_REG_8BIT: | |
173 | data[2] = val; | |
174 | break; | |
175 | case SMIA_REG_16BIT: | |
176 | data[2] = val >> 8; | |
177 | data[3] = val; | |
178 | break; | |
179 | case SMIA_REG_32BIT: | |
180 | data[2] = val >> 24; | |
181 | data[3] = val >> 16; | |
182 | data[4] = val >> 8; | |
183 | data[5] = val; | |
184 | break; | |
185 | default: | |
186 | BUG(); | |
187 | } | |
188 | ||
189 | for (retries = 0; retries < 5; retries++) { | |
190 | /* | |
191 | * Due to unknown reason sensor stops responding. This | |
192 | * loop is a temporaty solution until the root cause | |
193 | * is found. | |
194 | */ | |
195 | r = i2c_transfer(client->adapter, &msg, 1); | |
196 | if (r == 1) { | |
197 | if (retries) | |
198 | dev_err(&client->dev, | |
199 | "sensor i2c stall encountered. " | |
200 | "retries: %d\n", retries); | |
201 | return 0; | |
202 | } | |
203 | ||
204 | usleep_range(2000, 2000); | |
205 | } | |
206 | ||
207 | dev_err(&client->dev, | |
208 | "wrote 0x%x to offset 0x%x error %d\n", val, offset, r); | |
209 | ||
210 | return r; | |
211 | } |