u-boot/drivers/i2c/i2c_core.c

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/*
* Copyright (C) 2009 Sergey Kubushyn <ksi@koi8.net>
*
* (C) Copyright 2012
* Heiko Schocher, DENX Software Engineering, hs@denx.de.
*
* Multibus/multiadapter I2C core functions (wrappers)
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <i2c.h>
struct i2c_adapter *i2c_get_adapter(int index)
{
struct i2c_adapter *i2c_adap_p = ll_entry_start(struct i2c_adapter,
i2c);
int max = ll_entry_count(struct i2c_adapter, i2c);
int i;
if (index >= max) {
printf("Error, wrong i2c adapter %d max %d possible\n",
index, max);
return i2c_adap_p;
}
if (index == 0)
return i2c_adap_p;
for (i = 0; i < index; i++)
i2c_adap_p++;
return i2c_adap_p;
}
#if !defined(CONFIG_SYS_I2C_DIRECT_BUS)
struct i2c_bus_hose i2c_bus[CONFIG_SYS_NUM_I2C_BUSES] =
CONFIG_SYS_I2C_BUSES;
#endif
DECLARE_GLOBAL_DATA_PTR;
void i2c_reloc_fixup(void)
{
#if defined(CONFIG_NEEDS_MANUAL_RELOC)
struct i2c_adapter *i2c_adap_p = ll_entry_start(struct i2c_adapter,
i2c);
struct i2c_adapter *tmp = i2c_adap_p;
int max = ll_entry_count(struct i2c_adapter, i2c);
int i;
unsigned long addr;
if (gd->reloc_off == 0)
return;
for (i = 0; i < max; i++) {
/* i2c_init() */
addr = (unsigned long)i2c_adap_p->init;
addr += gd->reloc_off;
i2c_adap_p->init = (void *)addr;
/* i2c_probe() */
addr = (unsigned long)i2c_adap_p->probe;
addr += gd->reloc_off;
i2c_adap_p->probe = (void *)addr;
/* i2c_read() */
addr = (unsigned long)i2c_adap_p->read;
addr += gd->reloc_off;
i2c_adap_p->read = (void *)addr;
/* i2c_write() */
addr = (unsigned long)i2c_adap_p->write;
addr += gd->reloc_off;
i2c_adap_p->write = (void *)addr;
/* i2c_set_bus_speed() */
addr = (unsigned long)i2c_adap_p->set_bus_speed;
addr += gd->reloc_off;
i2c_adap_p->set_bus_speed = (void *)addr;
/* name */
addr = (unsigned long)i2c_adap_p->name;
addr += gd->reloc_off;
i2c_adap_p->name = (char *)addr;
tmp++;
i2c_adap_p = tmp;
}
#endif
}
#ifndef CONFIG_SYS_I2C_DIRECT_BUS
/*
* i2c_mux_set()
* -------------
*
* This turns on the given channel on I2C multiplexer chip connected to
* a given I2C adapter directly or via other multiplexers. In the latter
* case the entire multiplexer chain must be initialized first starting
* with the one connected directly to the adapter. When disabling a chain
* muxes must be programmed in reverse order, starting with the one
* farthest from the adapter.
*
* mux_id is the multiplexer chip type from defined in i2c.h. So far only
* NXP (Philips) PCA954x multiplexers are supported. Switches are NOT
* supported (anybody uses them?)
*/
static int i2c_mux_set(struct i2c_adapter *adap, int mux_id, int chip,
int channel)
{
uint8_t buf;
int ret;
/* channel < 0 - turn off the mux */
if (channel < 0) {
buf = 0;
ret = adap->write(adap, chip, 0, 0, &buf, 1);
if (ret)
printf("%s: Could not turn off the mux.\n", __func__);
return ret;
}
switch (mux_id) {
case I2C_MUX_PCA9540_ID:
case I2C_MUX_PCA9542_ID:
if (channel > 1)
return -1;
buf = (uint8_t)((channel & 0x01) | (1 << 2));
break;
case I2C_MUX_PCA9544_ID:
if (channel > 3)
return -1;
buf = (uint8_t)((channel & 0x03) | (1 << 2));
break;
case I2C_MUX_PCA9547_ID:
if (channel > 7)
return -1;
buf = (uint8_t)((channel & 0x07) | (1 << 3));
break;
case I2C_MUX_PCA9548_ID:
if (channel > 7)
return -1;
buf = (uint8_t)(0x01 << channel);
break;
default:
printf("%s: wrong mux id: %d\n", __func__, mux_id);
return -1;
}
ret = adap->write(adap, chip, 0, 0, &buf, 1);
if (ret)
printf("%s: could not set mux: id: %d chip: %x channel: %d\n",
__func__, mux_id, chip, channel);
return ret;
}
static int i2c_mux_set_all(void)
{
struct i2c_bus_hose *i2c_bus_tmp = &i2c_bus[I2C_BUS];
int i;
/* Connect requested bus if behind muxes */
if (i2c_bus_tmp->next_hop[0].chip != 0) {
/* Set all muxes along the path to that bus */
for (i = 0; i < CONFIG_SYS_I2C_MAX_HOPS; i++) {
int ret;
if (i2c_bus_tmp->next_hop[i].chip == 0)
break;
ret = i2c_mux_set(I2C_ADAP,
i2c_bus_tmp->next_hop[i].mux.id,
i2c_bus_tmp->next_hop[i].chip,
i2c_bus_tmp->next_hop[i].channel);
if (ret != 0)
return ret;
}
}
return 0;
}
static int i2c_mux_disconnect_all(void)
{
struct i2c_bus_hose *i2c_bus_tmp = &i2c_bus[I2C_BUS];
int i;
uint8_t buf = 0;
if (I2C_ADAP->init_done == 0)
return 0;
/* Disconnect current bus (turn off muxes if any) */
if ((i2c_bus_tmp->next_hop[0].chip != 0) &&
(I2C_ADAP->init_done != 0)) {
i = CONFIG_SYS_I2C_MAX_HOPS;
do {
uint8_t chip;
int ret;
chip = i2c_bus_tmp->next_hop[--i].chip;
if (chip == 0)
continue;
ret = I2C_ADAP->write(I2C_ADAP, chip, 0, 0, &buf, 1);
if (ret != 0) {
printf("i2c: mux disconnect error\n");
return ret;
}
} while (i > 0);
}
return 0;
}
#endif
/*
* i2c_init_bus():
* ---------------
*
* Initializes one bus. Will initialize the parent adapter. No current bus
* changes, no mux (if any) setup.
*/
static void i2c_init_bus(unsigned int bus_no, int speed, int slaveaddr)
{
if (bus_no >= CONFIG_SYS_NUM_I2C_BUSES)
return;
I2C_ADAP->init(I2C_ADAP, speed, slaveaddr);
if (gd->flags & GD_FLG_RELOC) {
I2C_ADAP->init_done = 1;
I2C_ADAP->speed = speed;
I2C_ADAP->slaveaddr = slaveaddr;
}
}
/* implement possible board specific board init */
__weak void i2c_init_board(void)
{
}
/*
* i2c_init_all():
*
* not longer needed, will deleted. Actual init the SPD_BUS
* for compatibility.
* i2c_adap[] must be initialized beforehead with function pointers and
* data, including speed and slaveaddr.
*/
void i2c_init_all(void)
{
i2c_init_board();
i2c_set_bus_num(CONFIG_SYS_SPD_BUS_NUM);
return;
}
/*
* i2c_get_bus_num():
* ------------------
*
* Returns index of currently active I2C bus. Zero-based.
*/
unsigned int i2c_get_bus_num(void)
{
return gd->cur_i2c_bus;
}
/*
* i2c_set_bus_num():
* ------------------
*
* Change the active I2C bus. Subsequent read/write calls will
* go to this one. Sets all of the muxes in a proper condition
* if that bus is behind muxes.
* If previously selected bus is behind the muxes turns off all the
* muxes along the path to that bus.
*
* bus - bus index, zero based
*
* Returns: 0 on success, not 0 on failure
*/
int i2c_set_bus_num(unsigned int bus)
{
int max;
if ((bus == I2C_BUS) && (I2C_ADAP->init_done > 0))
return 0;
#ifndef CONFIG_SYS_I2C_DIRECT_BUS
if (bus >= CONFIG_SYS_NUM_I2C_BUSES)
return -1;
#endif
max = ll_entry_count(struct i2c_adapter, i2c);
if (I2C_ADAPTER(bus) >= max) {
printf("Error, wrong i2c adapter %d max %d possible\n",
I2C_ADAPTER(bus), max);
return -2;
}
#ifndef CONFIG_SYS_I2C_DIRECT_BUS
i2c_mux_disconnect_all();
#endif
gd->cur_i2c_bus = bus;
if (I2C_ADAP->init_done == 0)
i2c_init_bus(bus, I2C_ADAP->speed, I2C_ADAP->slaveaddr);
#ifndef CONFIG_SYS_I2C_DIRECT_BUS
i2c_mux_set_all();
#endif
return 0;
}
/*
* Probe the given I2C chip address. Returns 0 if a chip responded,
* not 0 on failure.
*/
int i2c_probe(uint8_t chip)
{
return I2C_ADAP->probe(I2C_ADAP, chip);
}
/*
* 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(uint8_t chip, unsigned int addr, int alen,
uint8_t *buffer, int len)
{
return I2C_ADAP->read(I2C_ADAP, chip, addr, alen, buffer, len);
}
int i2c_write(uint8_t chip, unsigned int addr, int alen,
uint8_t *buffer, int len)
{
return I2C_ADAP->write(I2C_ADAP, chip, addr, alen, buffer, len);
}
unsigned int i2c_set_bus_speed(unsigned int speed)
{
unsigned int ret;
if (I2C_ADAP->set_bus_speed == NULL)
return 0;
ret = I2C_ADAP->set_bus_speed(I2C_ADAP, speed);
if (gd->flags & GD_FLG_RELOC)
I2C_ADAP->speed = (ret == 0) ? speed : 0;
return ret;
}
unsigned int i2c_get_bus_speed(void)
{
struct i2c_adapter *cur = I2C_ADAP;
return cur->speed;
}
uint8_t i2c_reg_read(uint8_t addr, uint8_t reg)
{
uint8_t buf;
#ifdef CONFIG_8xx
/* MPC8xx needs this. Maybe one day we can get rid of it. */
/* maybe it is now the time for it ... */
i2c_set_bus_num(i2c_get_bus_num());
#endif
i2c_read(addr, reg, 1, &buf, 1);
#ifdef DEBUG
printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
__func__, i2c_get_bus_num(), addr, reg, buf);
#endif
return buf;
}
void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val)
{
#ifdef CONFIG_8xx
/* MPC8xx needs this. Maybe one day we can get rid of it. */
/* maybe it is now the time for it ... */
i2c_set_bus_num(i2c_get_bus_num());
#endif
#ifdef DEBUG
printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
__func__, i2c_get_bus_num(), addr, reg, val);
#endif
i2c_write(addr, reg, 1, &val, 1);
}
__weak void i2c_init(int speed, int slaveaddr)
{
i2c_init_bus(i2c_get_bus_num(), speed, slaveaddr);
}