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Diffstat (limited to 'drivers/i2c/i2c_core.c')
| -rw-r--r-- | drivers/i2c/i2c_core.c | 402 |
1 files changed, 402 insertions, 0 deletions
diff --git a/drivers/i2c/i2c_core.c b/drivers/i2c/i2c_core.c new file mode 100644 index 000000000..d1072e819 --- /dev/null +++ b/drivers/i2c/i2c_core.c @@ -0,0 +1,402 @@ +/* + * 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++) { + /* adapter itself */ + addr = (unsigned long)i2c_adap_p; + addr += gd->reloc_off; + i2c_adap_p = (struct i2c_adapter *)addr; + /* i2c_init() */ + addr = (unsigned long)i2c_adap_p->init; + addr += gd->reloc_off; + i2c_adap_p->init = (void (*)(int, int))addr; + /* i2c_probe() */ + addr = (unsigned long)i2c_adap_p->probe; + addr += gd->reloc_off; + i2c_adap_p->probe = (int (*)(uint8_t))addr; + /* i2c_read() */ + addr = (unsigned long)i2c_adap_p->read; + addr += gd->reloc_off; + i2c_adap_p->read = (int (*)(uint8_t, uint, int, uint8_t *, + int))addr; + /* i2c_write() */ + addr = (unsigned long)i2c_adap_p->write; + addr += gd->reloc_off; + i2c_adap_p->write = (int (*)(uint8_t, uint, int, uint8_t *, + int))addr; + /* i2c_set_bus_speed() */ + addr = (unsigned long)i2c_adap_p->set_bus_speed; + addr += gd->reloc_off; + i2c_adap_p->set_bus_speed = (uint (*)(uint))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; + 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_disconnet_all(void) +{ + struct i2c_bus_hose *i2c_bus_tmp = &i2c_bus[I2C_BUS]; + int i; + uint8_t buf; + + 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 diconnect 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 */ +static void __def_i2c_init_board(void) +{ +} +void i2c_init_board(void) + __attribute__((weak, alias("__def_i2c_init_board"))); + +/* + * 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 = 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 + if (bus >= CONFIG_SYS_NUM_I2C_BUSES) + return -1; +#endif + + if ((bus == I2C_BUS) && (I2C_ADAP->init_done > 0)) + return 0; + +#ifndef CONFIG_SYS_I2C_DIRECT_BUS + i2c_mux_disconnet_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; + + 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); +} + +void __i2c_init(int speed, int slaveaddr) +{ + i2c_init_bus(i2c_get_bus_num(), speed, slaveaddr); +} +void i2c_init(int speed, int slaveaddr) + __attribute__((weak, alias("__i2c_init"))); |