u-boot/drivers/i2c/i2c_core.c
Heiko Schocher 5b8e76c35e powerpc, 8xx: remove support for 8xx
There was for long time no activity in the 8xx area.
We need to go further and convert to Kconfig, but it
turned out, nobody is interested anymore in 8xx,
so remove it (with a heavy heart, knowing that I remove
here the root of U-Boot).

Signed-off-by: Heiko Schocher <hs@denx.de>
2017-06-12 08:37:55 -04:00

349 lines
7.7 KiB
C

/*
* 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;
#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)
{
}
/* implement possible for i2c specific early i2c init */
__weak void i2c_early_init_f(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;
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 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);
}