diff options
Diffstat (limited to 'drivers/video/fbdev/mb862xx/mb862xx-i2c.c')
-rw-r--r-- | drivers/video/fbdev/mb862xx/mb862xx-i2c.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/drivers/video/fbdev/mb862xx/mb862xx-i2c.c b/drivers/video/fbdev/mb862xx/mb862xx-i2c.c new file mode 100644 index 000000000000..c87e17afb3e2 --- /dev/null +++ b/drivers/video/fbdev/mb862xx/mb862xx-i2c.c | |||
@@ -0,0 +1,179 @@ | |||
1 | /* | ||
2 | * Coral-P(A)/Lime I2C adapter driver | ||
3 | * | ||
4 | * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de> | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU General Public License version 2 as | ||
8 | * published by the Free Software Foundation. | ||
9 | * | ||
10 | */ | ||
11 | |||
12 | #include <linux/fb.h> | ||
13 | #include <linux/i2c.h> | ||
14 | #include <linux/io.h> | ||
15 | #include <linux/delay.h> | ||
16 | #include <linux/export.h> | ||
17 | |||
18 | #include "mb862xxfb.h" | ||
19 | #include "mb862xx_reg.h" | ||
20 | |||
21 | static int mb862xx_i2c_wait_event(struct i2c_adapter *adap) | ||
22 | { | ||
23 | struct mb862xxfb_par *par = adap->algo_data; | ||
24 | u32 reg; | ||
25 | |||
26 | do { | ||
27 | udelay(10); | ||
28 | reg = inreg(i2c, GC_I2C_BCR); | ||
29 | if (reg & (I2C_INT | I2C_BER)) | ||
30 | break; | ||
31 | } while (1); | ||
32 | |||
33 | return (reg & I2C_BER) ? 0 : 1; | ||
34 | } | ||
35 | |||
36 | static int mb862xx_i2c_do_address(struct i2c_adapter *adap, int addr) | ||
37 | { | ||
38 | struct mb862xxfb_par *par = adap->algo_data; | ||
39 | |||
40 | outreg(i2c, GC_I2C_DAR, addr); | ||
41 | outreg(i2c, GC_I2C_CCR, I2C_CLOCK_AND_ENABLE); | ||
42 | outreg(i2c, GC_I2C_BCR, par->i2c_rs ? I2C_REPEATED_START : I2C_START); | ||
43 | if (!mb862xx_i2c_wait_event(adap)) | ||
44 | return -EIO; | ||
45 | par->i2c_rs = !(inreg(i2c, GC_I2C_BSR) & I2C_LRB); | ||
46 | return par->i2c_rs; | ||
47 | } | ||
48 | |||
49 | static int mb862xx_i2c_write_byte(struct i2c_adapter *adap, u8 byte) | ||
50 | { | ||
51 | struct mb862xxfb_par *par = adap->algo_data; | ||
52 | |||
53 | outreg(i2c, GC_I2C_DAR, byte); | ||
54 | outreg(i2c, GC_I2C_BCR, I2C_START); | ||
55 | if (!mb862xx_i2c_wait_event(adap)) | ||
56 | return -EIO; | ||
57 | return !(inreg(i2c, GC_I2C_BSR) & I2C_LRB); | ||
58 | } | ||
59 | |||
60 | static int mb862xx_i2c_read_byte(struct i2c_adapter *adap, u8 *byte, int last) | ||
61 | { | ||
62 | struct mb862xxfb_par *par = adap->algo_data; | ||
63 | |||
64 | outreg(i2c, GC_I2C_BCR, I2C_START | (last ? 0 : I2C_ACK)); | ||
65 | if (!mb862xx_i2c_wait_event(adap)) | ||
66 | return 0; | ||
67 | *byte = inreg(i2c, GC_I2C_DAR); | ||
68 | return 1; | ||
69 | } | ||
70 | |||
71 | static void mb862xx_i2c_stop(struct i2c_adapter *adap) | ||
72 | { | ||
73 | struct mb862xxfb_par *par = adap->algo_data; | ||
74 | |||
75 | outreg(i2c, GC_I2C_BCR, I2C_STOP); | ||
76 | outreg(i2c, GC_I2C_CCR, I2C_DISABLE); | ||
77 | par->i2c_rs = 0; | ||
78 | } | ||
79 | |||
80 | static int mb862xx_i2c_read(struct i2c_adapter *adap, struct i2c_msg *m) | ||
81 | { | ||
82 | int i, ret = 0; | ||
83 | int last = m->len - 1; | ||
84 | |||
85 | for (i = 0; i < m->len; i++) { | ||
86 | if (!mb862xx_i2c_read_byte(adap, &m->buf[i], i == last)) { | ||
87 | ret = -EIO; | ||
88 | break; | ||
89 | } | ||
90 | } | ||
91 | return ret; | ||
92 | } | ||
93 | |||
94 | static int mb862xx_i2c_write(struct i2c_adapter *adap, struct i2c_msg *m) | ||
95 | { | ||
96 | int i, ret = 0; | ||
97 | |||
98 | for (i = 0; i < m->len; i++) { | ||
99 | if (!mb862xx_i2c_write_byte(adap, m->buf[i])) { | ||
100 | ret = -EIO; | ||
101 | break; | ||
102 | } | ||
103 | } | ||
104 | return ret; | ||
105 | } | ||
106 | |||
107 | static int mb862xx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, | ||
108 | int num) | ||
109 | { | ||
110 | struct mb862xxfb_par *par = adap->algo_data; | ||
111 | struct i2c_msg *m; | ||
112 | int addr; | ||
113 | int i = 0, err = 0; | ||
114 | |||
115 | dev_dbg(par->dev, "%s: %d msgs\n", __func__, num); | ||
116 | |||
117 | for (i = 0; i < num; i++) { | ||
118 | m = &msgs[i]; | ||
119 | if (!m->len) { | ||
120 | dev_dbg(par->dev, "%s: null msgs\n", __func__); | ||
121 | continue; | ||
122 | } | ||
123 | addr = m->addr; | ||
124 | if (m->flags & I2C_M_RD) | ||
125 | addr |= 1; | ||
126 | |||
127 | err = mb862xx_i2c_do_address(adap, addr); | ||
128 | if (err < 0) | ||
129 | break; | ||
130 | if (m->flags & I2C_M_RD) | ||
131 | err = mb862xx_i2c_read(adap, m); | ||
132 | else | ||
133 | err = mb862xx_i2c_write(adap, m); | ||
134 | } | ||
135 | |||
136 | if (i) | ||
137 | mb862xx_i2c_stop(adap); | ||
138 | |||
139 | return (err < 0) ? err : i; | ||
140 | } | ||
141 | |||
142 | static u32 mb862xx_func(struct i2c_adapter *adap) | ||
143 | { | ||
144 | return I2C_FUNC_SMBUS_BYTE_DATA; | ||
145 | } | ||
146 | |||
147 | static const struct i2c_algorithm mb862xx_algo = { | ||
148 | .master_xfer = mb862xx_xfer, | ||
149 | .functionality = mb862xx_func, | ||
150 | }; | ||
151 | |||
152 | static struct i2c_adapter mb862xx_i2c_adapter = { | ||
153 | .name = "MB862xx I2C adapter", | ||
154 | .algo = &mb862xx_algo, | ||
155 | .owner = THIS_MODULE, | ||
156 | }; | ||
157 | |||
158 | int mb862xx_i2c_init(struct mb862xxfb_par *par) | ||
159 | { | ||
160 | int ret; | ||
161 | |||
162 | mb862xx_i2c_adapter.algo_data = par; | ||
163 | par->adap = &mb862xx_i2c_adapter; | ||
164 | |||
165 | ret = i2c_add_adapter(par->adap); | ||
166 | if (ret < 0) { | ||
167 | dev_err(par->dev, "failed to add %s\n", | ||
168 | mb862xx_i2c_adapter.name); | ||
169 | } | ||
170 | return ret; | ||
171 | } | ||
172 | |||
173 | void mb862xx_i2c_exit(struct mb862xxfb_par *par) | ||
174 | { | ||
175 | if (par->adap) { | ||
176 | i2c_del_adapter(par->adap); | ||
177 | par->adap = NULL; | ||
178 | } | ||
179 | } | ||