2 * Coral-P(A)/Lime I2C adapter driver
4 * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de>
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.
13 #include <linux/i2c.h>
15 #include <linux/delay.h>
17 #include "mb862xxfb.h"
18 #include "mb862xx_reg.h"
20 static int mb862xx_i2c_wait_event(struct i2c_adapter *adap)
22 struct mb862xxfb_par *par = adap->algo_data;
27 reg = inreg(i2c, GC_I2C_BCR);
28 if (reg & (I2C_INT | I2C_BER))
32 return (reg & I2C_BER) ? 0 : 1;
35 static int mb862xx_i2c_do_address(struct i2c_adapter *adap, int addr)
37 struct mb862xxfb_par *par = adap->algo_data;
39 outreg(i2c, GC_I2C_DAR, addr);
40 outreg(i2c, GC_I2C_CCR, I2C_CLOCK_AND_ENABLE);
41 outreg(i2c, GC_I2C_BCR, par->i2c_rs ? I2C_REPEATED_START : I2C_START);
42 if (!mb862xx_i2c_wait_event(adap))
44 par->i2c_rs = !(inreg(i2c, GC_I2C_BSR) & I2C_LRB);
48 static int mb862xx_i2c_write_byte(struct i2c_adapter *adap, u8 byte)
50 struct mb862xxfb_par *par = adap->algo_data;
52 outreg(i2c, GC_I2C_DAR, byte);
53 outreg(i2c, GC_I2C_BCR, I2C_START);
54 if (!mb862xx_i2c_wait_event(adap))
56 return !(inreg(i2c, GC_I2C_BSR) & I2C_LRB);
59 static int mb862xx_i2c_read_byte(struct i2c_adapter *adap, u8 *byte, int last)
61 struct mb862xxfb_par *par = adap->algo_data;
63 outreg(i2c, GC_I2C_BCR, I2C_START | (last ? 0 : I2C_ACK));
64 if (!mb862xx_i2c_wait_event(adap))
66 *byte = inreg(i2c, GC_I2C_DAR);
70 void mb862xx_i2c_stop(struct i2c_adapter *adap)
72 struct mb862xxfb_par *par = adap->algo_data;
74 outreg(i2c, GC_I2C_BCR, I2C_STOP);
75 outreg(i2c, GC_I2C_CCR, I2C_DISABLE);
79 static int mb862xx_i2c_read(struct i2c_adapter *adap, struct i2c_msg *m)
82 int last = m->len - 1;
84 for (i = 0; i < m->len; i++) {
85 if (!mb862xx_i2c_read_byte(adap, &m->buf[i], i == last)) {
93 static int mb862xx_i2c_write(struct i2c_adapter *adap, struct i2c_msg *m)
97 for (i = 0; i < m->len; i++) {
98 if (!mb862xx_i2c_write_byte(adap, m->buf[i])) {
106 static int mb862xx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
109 struct mb862xxfb_par *par = adap->algo_data;
114 dev_dbg(par->dev, "%s: %d msgs\n", __func__, num);
116 for (i = 0; i < num; i++) {
119 dev_dbg(par->dev, "%s: null msgs\n", __func__);
123 if (m->flags & I2C_M_RD)
126 err = mb862xx_i2c_do_address(adap, addr);
129 if (m->flags & I2C_M_RD)
130 err = mb862xx_i2c_read(adap, m);
132 err = mb862xx_i2c_write(adap, m);
136 mb862xx_i2c_stop(adap);
138 return (err < 0) ? err : i;
141 static u32 mb862xx_func(struct i2c_adapter *adap)
143 return I2C_FUNC_SMBUS_BYTE_DATA;
146 static const struct i2c_algorithm mb862xx_algo = {
147 .master_xfer = mb862xx_xfer,
148 .functionality = mb862xx_func,
151 static struct i2c_adapter mb862xx_i2c_adapter = {
152 .name = "MB862xx I2C adapter",
153 .algo = &mb862xx_algo,
154 .owner = THIS_MODULE,
157 int mb862xx_i2c_init(struct mb862xxfb_par *par)
161 mb862xx_i2c_adapter.algo_data = par;
162 par->adap = &mb862xx_i2c_adapter;
164 ret = i2c_add_adapter(par->adap);
166 dev_err(par->dev, "failed to add %s\n",
167 mb862xx_i2c_adapter.name);
172 void mb862xx_i2c_exit(struct mb862xxfb_par *par)
175 i2c_del_adapter(par->adap);