mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
168 lines
3.5 KiB
168 lines
3.5 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* Coral-P(A)/Lime I2C adapter driver |
|
* |
|
* (C) 2011 DENX Software Engineering, Anatolij Gustschin <[email protected]> |
|
*/ |
|
|
|
#include <linux/fb.h> |
|
#include <linux/i2c.h> |
|
#include <linux/io.h> |
|
#include <linux/delay.h> |
|
#include <linux/export.h> |
|
|
|
#include "mb862xxfb.h" |
|
#include "mb862xx_reg.h" |
|
|
|
static int mb862xx_i2c_wait_event(struct i2c_adapter *adap) |
|
{ |
|
struct mb862xxfb_par *par = adap->algo_data; |
|
u32 reg; |
|
|
|
do { |
|
udelay(10); |
|
reg = inreg(i2c, GC_I2C_BCR); |
|
if (reg & (I2C_INT | I2C_BER)) |
|
break; |
|
} while (1); |
|
|
|
return (reg & I2C_BER) ? 0 : 1; |
|
} |
|
|
|
static int mb862xx_i2c_do_address(struct i2c_adapter *adap, int addr) |
|
{ |
|
struct mb862xxfb_par *par = adap->algo_data; |
|
|
|
outreg(i2c, GC_I2C_DAR, addr); |
|
outreg(i2c, GC_I2C_CCR, I2C_CLOCK_AND_ENABLE); |
|
outreg(i2c, GC_I2C_BCR, par->i2c_rs ? I2C_REPEATED_START : I2C_START); |
|
if (!mb862xx_i2c_wait_event(adap)) |
|
return -EIO; |
|
par->i2c_rs = !(inreg(i2c, GC_I2C_BSR) & I2C_LRB); |
|
return par->i2c_rs; |
|
} |
|
|
|
static int mb862xx_i2c_write_byte(struct i2c_adapter *adap, u8 byte) |
|
{ |
|
struct mb862xxfb_par *par = adap->algo_data; |
|
|
|
outreg(i2c, GC_I2C_DAR, byte); |
|
outreg(i2c, GC_I2C_BCR, I2C_START); |
|
if (!mb862xx_i2c_wait_event(adap)) |
|
return -EIO; |
|
return !(inreg(i2c, GC_I2C_BSR) & I2C_LRB); |
|
} |
|
|
|
static int mb862xx_i2c_read_byte(struct i2c_adapter *adap, u8 *byte, int last) |
|
{ |
|
struct mb862xxfb_par *par = adap->algo_data; |
|
|
|
outreg(i2c, GC_I2C_BCR, I2C_START | (last ? 0 : I2C_ACK)); |
|
if (!mb862xx_i2c_wait_event(adap)) |
|
return 0; |
|
*byte = inreg(i2c, GC_I2C_DAR); |
|
return 1; |
|
} |
|
|
|
static void mb862xx_i2c_stop(struct i2c_adapter *adap) |
|
{ |
|
struct mb862xxfb_par *par = adap->algo_data; |
|
|
|
outreg(i2c, GC_I2C_BCR, I2C_STOP); |
|
outreg(i2c, GC_I2C_CCR, I2C_DISABLE); |
|
par->i2c_rs = 0; |
|
} |
|
|
|
static int mb862xx_i2c_read(struct i2c_adapter *adap, struct i2c_msg *m) |
|
{ |
|
int i, ret = 0; |
|
int last = m->len - 1; |
|
|
|
for (i = 0; i < m->len; i++) { |
|
if (!mb862xx_i2c_read_byte(adap, &m->buf[i], i == last)) { |
|
ret = -EIO; |
|
break; |
|
} |
|
} |
|
return ret; |
|
} |
|
|
|
static int mb862xx_i2c_write(struct i2c_adapter *adap, struct i2c_msg *m) |
|
{ |
|
int i, ret = 0; |
|
|
|
for (i = 0; i < m->len; i++) { |
|
if (!mb862xx_i2c_write_byte(adap, m->buf[i])) { |
|
ret = -EIO; |
|
break; |
|
} |
|
} |
|
return ret; |
|
} |
|
|
|
static int mb862xx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, |
|
int num) |
|
{ |
|
struct mb862xxfb_par *par = adap->algo_data; |
|
struct i2c_msg *m; |
|
int addr; |
|
int i = 0, err = 0; |
|
|
|
dev_dbg(par->dev, "%s: %d msgs\n", __func__, num); |
|
|
|
for (i = 0; i < num; i++) { |
|
m = &msgs[i]; |
|
if (!m->len) { |
|
dev_dbg(par->dev, "%s: null msgs\n", __func__); |
|
continue; |
|
} |
|
addr = m->addr; |
|
if (m->flags & I2C_M_RD) |
|
addr |= 1; |
|
|
|
err = mb862xx_i2c_do_address(adap, addr); |
|
if (err < 0) |
|
break; |
|
if (m->flags & I2C_M_RD) |
|
err = mb862xx_i2c_read(adap, m); |
|
else |
|
err = mb862xx_i2c_write(adap, m); |
|
} |
|
|
|
if (i) |
|
mb862xx_i2c_stop(adap); |
|
|
|
return (err < 0) ? err : i; |
|
} |
|
|
|
static u32 mb862xx_func(struct i2c_adapter *adap) |
|
{ |
|
return I2C_FUNC_SMBUS_BYTE_DATA; |
|
} |
|
|
|
static const struct i2c_algorithm mb862xx_algo = { |
|
.master_xfer = mb862xx_xfer, |
|
.functionality = mb862xx_func, |
|
}; |
|
|
|
static struct i2c_adapter mb862xx_i2c_adapter = { |
|
.name = "MB862xx I2C adapter", |
|
.algo = &mb862xx_algo, |
|
.owner = THIS_MODULE, |
|
}; |
|
|
|
int mb862xx_i2c_init(struct mb862xxfb_par *par) |
|
{ |
|
mb862xx_i2c_adapter.algo_data = par; |
|
par->adap = &mb862xx_i2c_adapter; |
|
|
|
return i2c_add_adapter(par->adap); |
|
} |
|
|
|
void mb862xx_i2c_exit(struct mb862xxfb_par *par) |
|
{ |
|
if (par->adap) { |
|
i2c_del_adapter(par->adap); |
|
par->adap = NULL; |
|
} |
|
}
|
|
|