pca9564_i2c.c
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/*
* File: drivers/i2c/pca9564.c
* Based on: drivers/i2c/s3c44b0_i2c.c
* Author:
*
* Created: 2009-06-23
* Description: PCA9564 i2c bridge driver
*
* Modified:
* Copyright 2009 CJSC "NII STT", http://www.niistt.ru/
*
* Bugs:
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <i2c.h>
#include <pca9564.h>
#include <asm/io.h>
#define PCA_STA (CONFIG_PCA9564_BASE + 0)
#define PCA_TO (CONFIG_PCA9564_BASE + 0)
#define PCA_DAT (CONFIG_PCA9564_BASE + (1 << 2))
#define PCA_ADR (CONFIG_PCA9564_BASE + (2 << 2))
#define PCA_CON (CONFIG_PCA9564_BASE + (3 << 2))
static unsigned char pca_read_reg(unsigned int reg)
{
return readb((void *)reg);
}
static void pca_write_reg(unsigned int reg, unsigned char value)
{
writeb(value, (void *)reg);
}
static int pca_wait_busy(void)
{
unsigned int timeout = 10000;
while (!(pca_read_reg(PCA_CON) & PCA_CON_SI) && --timeout)
udelay(1);
if (timeout == 0)
debug("I2C timeout!\n");
debug("CON = 0x%02x, STA = 0x%02x\n", pca_read_reg(PCA_CON),
pca_read_reg(PCA_STA));
return timeout ? 0 : 1;
}
/*=====================================================================*/
/* Public Functions */
/*=====================================================================*/
/*-----------------------------------------------------------------------
* Initialization
*/
void i2c_init(int speed, int slaveaddr)
{
pca_write_reg(PCA_CON, PCA_CON_ENSIO | speed);
}
/*
* Probe the given I2C chip address. Returns 0 if a chip responded,
* not 0 on failure.
*/
int i2c_probe(uchar chip)
{
unsigned char res;
pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO);
pca_wait_busy();
pca_write_reg(PCA_CON, PCA_CON_STA | PCA_CON_ENSIO);
pca_write_reg(PCA_DAT, (chip << 1) | 1);
res = pca_wait_busy();
if ((res == 0) && (pca_read_reg(PCA_STA) == 0x48))
res = 1;
pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO);
return res;
}
/*
* Read/Write interface:
* chip: I2C chip address, range 0..127
* addr: Memory (register) address within the chip
* alen: Number of bytes to use for addr (typically 1, 2 for larger
* memories, 0 for register type devices with only one
* register)
* buffer: Where to read/write the data
* len: How many bytes to read/write
*
* Returns: 0 on success, not 0 on failure
*/
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
int i;
pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
pca_wait_busy();
pca_write_reg(PCA_CON, PCA_CON_ENSIO);
pca_write_reg(PCA_DAT, (chip << 1));
pca_wait_busy();
pca_write_reg(PCA_CON, PCA_CON_ENSIO);
if (alen > 0) {
pca_write_reg(PCA_DAT, addr);
pca_wait_busy();
pca_write_reg(PCA_CON, PCA_CON_ENSIO);
}
pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO);
udelay(500);
pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
pca_wait_busy();
pca_write_reg(PCA_CON, PCA_CON_ENSIO);
pca_write_reg(PCA_DAT, (chip << 1) | 1);
pca_wait_busy();
for (i = 0; i < len; ++i) {
if (i == len - 1)
pca_write_reg(PCA_CON, PCA_CON_ENSIO);
else
pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_AA);
pca_wait_busy();
buffer[i] = pca_read_reg(PCA_DAT);
}
pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STO);
return 0;
}
int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
int i;
pca_write_reg(PCA_CON, PCA_CON_ENSIO | PCA_CON_STA);
pca_wait_busy();
pca_write_reg(PCA_CON, PCA_CON_ENSIO);
pca_write_reg(PCA_DAT, chip << 1);
pca_wait_busy();
pca_write_reg(PCA_CON, PCA_CON_ENSIO);
if (alen > 0) {
pca_write_reg(PCA_DAT, addr);
pca_wait_busy();
pca_write_reg(PCA_CON, PCA_CON_ENSIO);
}
for (i = 0; i < len; ++i) {
pca_write_reg(PCA_DAT, buffer[i]);
pca_wait_busy();
pca_write_reg(PCA_CON, PCA_CON_ENSIO);
}
pca_write_reg(PCA_CON, PCA_CON_STO | PCA_CON_ENSIO);
return 0;
}