u-boot/drivers/i2c/ihs_i2c.c

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/*
* (C) Copyright 2013
* Dirk Eibach, Guntermann & Drunck GmbH, eibach@gdsys.de
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <i2c.h>
#include <gdsys_fpga.h>
DECLARE_GLOBAL_DATA_PTR;
enum {
I2CINT_ERROR_EV = 1 << 13,
I2CINT_TRANSMIT_EV = 1 << 14,
I2CINT_RECEIVE_EV = 1 << 15,
};
enum {
I2CMB_WRITE = 1 << 10,
I2CMB_2BYTE = 1 << 11,
I2CMB_HOLD_BUS = 1 << 13,
I2CMB_NATIVE = 2 << 14,
};
static int wait_for_int(bool read)
{
u16 val;
unsigned int ctr = 0;
FPGA_GET_REG(I2C_ADAP_HWNR, i2c.interrupt_status, &val);
while (!(val & (I2CINT_ERROR_EV
| (read ? I2CINT_RECEIVE_EV : I2CINT_TRANSMIT_EV)))) {
udelay(10);
if (ctr++ > 5000) {
return 1;
}
FPGA_GET_REG(I2C_ADAP_HWNR, i2c.interrupt_status, &val);
}
return (val & I2CINT_ERROR_EV) ? 1 : 0;
}
static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read,
bool is_last)
{
u16 val;
FPGA_SET_REG(I2C_ADAP_HWNR, i2c.interrupt_status, I2CINT_ERROR_EV
| I2CINT_RECEIVE_EV | I2CINT_TRANSMIT_EV);
FPGA_GET_REG(I2C_ADAP_HWNR, i2c.interrupt_status, &val);
if (!read && len) {
val = buffer[0];
if (len > 1)
val |= buffer[1] << 8;
FPGA_SET_REG(I2C_ADAP_HWNR, i2c.write_mailbox_ext, val);
}
FPGA_SET_REG(I2C_ADAP_HWNR, i2c.write_mailbox,
I2CMB_NATIVE
| (read ? 0 : I2CMB_WRITE)
| (chip << 1)
| ((len > 1) ? I2CMB_2BYTE : 0)
| (is_last ? 0 : I2CMB_HOLD_BUS));
if (wait_for_int(read))
return 1;
if (read) {
FPGA_GET_REG(I2C_ADAP_HWNR, i2c.read_mailbox_ext, &val);
buffer[0] = val & 0xff;
if (len > 1)
buffer[1] = val >> 8;
}
return 0;
}
static int ihs_i2c_address(uchar chip, uint addr, int alen, bool hold_bus)
{
int shift = (alen-1) * 8;
while (alen) {
int transfer = MIN(alen, 2);
uchar buf[2];
bool is_last = alen <= transfer;
buf[0] = addr >> shift;
if (alen > 1)
buf[1] = addr >> (shift - 8);
if (ihs_i2c_transfer(chip, buf, transfer, false,
hold_bus ? false : is_last))
return 1;
shift -= 16;
alen -= transfer;
}
return 0;
}
static int ihs_i2c_access(struct i2c_adapter *adap, uchar chip, uint addr,
int alen, uchar *buffer, int len, bool read)
{
if (len <= 0)
return 1;
if (ihs_i2c_address(chip, addr, alen, !read))
return 1;
while (len) {
int transfer = MIN(len, 2);
if (ihs_i2c_transfer(chip, buffer, transfer, read,
len <= transfer))
return 1;
buffer += transfer;
addr += transfer;
len -= transfer;
}
return 0;
}
static void ihs_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
{
#ifdef CONFIG_SYS_I2C_INIT_BOARD
/*
* Call board specific i2c bus reset routine before accessing the
* environment, which might be in a chip on that bus. For details
* about this problem see doc/I2C_Edge_Conditions.
*/
i2c_init_board();
#endif
}
static int ihs_i2c_probe(struct i2c_adapter *adap, uchar chip)
{
uchar buffer[2];
if (ihs_i2c_transfer(chip, buffer, 0, true, true))
return 1;
return 0;
}
static int ihs_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
int alen, uchar *buffer, int len)
{
return ihs_i2c_access(adap, chip, addr, alen, buffer, len, true);
}
static int ihs_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
int alen, uchar *buffer, int len)
{
return ihs_i2c_access(adap, chip, addr, alen, buffer, len, false);
}
static unsigned int ihs_i2c_set_bus_speed(struct i2c_adapter *adap,
unsigned int speed)
{
if (speed != adap->speed)
return 1;
return speed;
}
/*
* Register IHS i2c adapters
*/
#ifdef CONFIG_SYS_I2C_IHS_CH0
U_BOOT_I2C_ADAP_COMPLETE(ihs0, ihs_i2c_init, ihs_i2c_probe,
ihs_i2c_read, ihs_i2c_write,
ihs_i2c_set_bus_speed,
CONFIG_SYS_I2C_IHS_SPEED_0,
CONFIG_SYS_I2C_IHS_SLAVE_0, 0)
#endif
#ifdef CONFIG_SYS_I2C_IHS_CH1
U_BOOT_I2C_ADAP_COMPLETE(ihs1, ihs_i2c_init, ihs_i2c_probe,
ihs_i2c_read, ihs_i2c_write,
ihs_i2c_set_bus_speed,
CONFIG_SYS_I2C_IHS_SPEED_1,
CONFIG_SYS_I2C_IHS_SLAVE_1, 1)
#endif
#ifdef CONFIG_SYS_I2C_IHS_CH2
U_BOOT_I2C_ADAP_COMPLETE(ihs2, ihs_i2c_init, ihs_i2c_probe,
ihs_i2c_read, ihs_i2c_write,
ihs_i2c_set_bus_speed,
CONFIG_SYS_I2C_IHS_SPEED_2,
CONFIG_SYS_I2C_IHS_SLAVE_2, 2)
#endif
#ifdef CONFIG_SYS_I2C_IHS_CH3
U_BOOT_I2C_ADAP_COMPLETE(ihs3, ihs_i2c_init, ihs_i2c_probe,
ihs_i2c_read, ihs_i2c_write,
ihs_i2c_set_bus_speed,
CONFIG_SYS_I2C_IHS_SPEED_3,
CONFIG_SYS_I2C_IHS_SLAVE_3, 3)
#endif