+++ /dev/null
-/*
- * i2c.c - driver for ADI TWI/I2C
- *
- * Copyright (c) 2006-2014 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later.
- *
- * NOTE: This driver should be converted to driver model before June 2017.
- * Please see doc/driver-model/i2c-howto.txt for instructions.
- */
-
-#include <common.h>
-#include <console.h>
-#include <i2c.h>
-
-#include <asm/clock.h>
-#include <asm/twi.h>
-#include <asm/io.h>
-
-static struct twi_regs *i2c_get_base(struct i2c_adapter *adap);
-
-/* Every register is 32bit aligned, but only 16bits in size */
-#define ureg(name) u16 name; u16 __pad_##name;
-struct twi_regs {
- ureg(clkdiv);
- ureg(control);
- ureg(slave_ctl);
- ureg(slave_stat);
- ureg(slave_addr);
- ureg(master_ctl);
- ureg(master_stat);
- ureg(master_addr);
- ureg(int_stat);
- ureg(int_mask);
- ureg(fifo_ctl);
- ureg(fifo_stat);
- char __pad[0x50];
- ureg(xmt_data8);
- ureg(xmt_data16);
- ureg(rcv_data8);
- ureg(rcv_data16);
-};
-#undef ureg
-
-#ifdef TWI_CLKDIV
-#define TWI0_CLKDIV TWI_CLKDIV
-# ifdef CONFIG_SYS_MAX_I2C_BUS
-# undef CONFIG_SYS_MAX_I2C_BUS
-# endif
-#define CONFIG_SYS_MAX_I2C_BUS 1
-#endif
-
-/*
- * The way speed is changed into duty often results in integer truncation
- * with 50% duty, so we'll force rounding up to the next duty by adding 1
- * to the max. In practice this will get us a speed of something like
- * 385 KHz. The other limit is easy to handle as it is only 8 bits.
- */
-#define I2C_SPEED_MAX 400000
-#define I2C_SPEED_TO_DUTY(speed) (5000000 / (speed))
-#define I2C_DUTY_MAX (I2C_SPEED_TO_DUTY(I2C_SPEED_MAX) + 1)
-#define I2C_DUTY_MIN 0xff /* 8 bit limited */
-#define SYS_I2C_DUTY I2C_SPEED_TO_DUTY(CONFIG_SYS_I2C_SPEED)
-/* Note: duty is inverse of speed, so the comparisons below are correct */
-#if SYS_I2C_DUTY < I2C_DUTY_MAX || SYS_I2C_DUTY > I2C_DUTY_MIN
-# error "The I2C hardware can only operate 20KHz - 400KHz"
-#endif
-
-/* All transfers are described by this data structure */
-struct adi_i2c_msg {
- u8 flags;
-#define I2C_M_COMBO 0x4
-#define I2C_M_STOP 0x2
-#define I2C_M_READ 0x1
- int len; /* msg length */
- u8 *buf; /* pointer to msg data */
- int alen; /* addr length */
- u8 *abuf; /* addr buffer */
-};
-
-/* Allow msec timeout per ~byte transfer */
-#define I2C_TIMEOUT 10
-
-/**
- * wait_for_completion - manage the actual i2c transfer
- * @msg: the i2c msg
- */
-static int wait_for_completion(struct twi_regs *twi, struct adi_i2c_msg *msg)
-{
- u16 int_stat, ctl;
- ulong timebase = get_timer(0);
-
- do {
- int_stat = readw(&twi->int_stat);
-
- if (int_stat & XMTSERV) {
- writew(XMTSERV, &twi->int_stat);
- if (msg->alen) {
- writew(*(msg->abuf++), &twi->xmt_data8);
- --msg->alen;
- } else if (!(msg->flags & I2C_M_COMBO) && msg->len) {
- writew(*(msg->buf++), &twi->xmt_data8);
- --msg->len;
- } else {
- ctl = readw(&twi->master_ctl);
- if (msg->flags & I2C_M_COMBO)
- writew(ctl | RSTART | MDIR,
- &twi->master_ctl);
- else
- writew(ctl | STOP, &twi->master_ctl);
- }
- }
- if (int_stat & RCVSERV) {
- writew(RCVSERV, &twi->int_stat);
- if (msg->len) {
- *(msg->buf++) = readw(&twi->rcv_data8);
- --msg->len;
- } else if (msg->flags & I2C_M_STOP) {
- ctl = readw(&twi->master_ctl);
- writew(ctl | STOP, &twi->master_ctl);
- }
- }
- if (int_stat & MERR) {
- writew(MERR, &twi->int_stat);
- return msg->len;
- }
- if (int_stat & MCOMP) {
- writew(MCOMP, &twi->int_stat);
- if (msg->flags & I2C_M_COMBO && msg->len) {
- ctl = readw(&twi->master_ctl);
- ctl = (ctl & ~RSTART) |
- (min(msg->len, 0xff) << 6) | MEN | MDIR;
- writew(ctl, &twi->master_ctl);
- } else
- break;
- }
-
- /* If we were able to do something, reset timeout */
- if (int_stat)
- timebase = get_timer(0);
-
- } while (get_timer(timebase) < I2C_TIMEOUT);
-
- return msg->len;
-}
-
-static int i2c_transfer(struct i2c_adapter *adap, uint8_t chip, uint addr,
- int alen, uint8_t *buffer, int len, uint8_t flags)
-{
- struct twi_regs *twi = i2c_get_base(adap);
- int ret;
- u16 ctl;
- uchar addr_buffer[] = {
- (addr >> 0),
- (addr >> 8),
- (addr >> 16),
- };
- struct adi_i2c_msg msg = {
- .flags = flags | (len >= 0xff ? I2C_M_STOP : 0),
- .buf = buffer,
- .len = len,
- .abuf = addr_buffer,
- .alen = alen,
- };
-
- /* wait for things to settle */
- while (readw(&twi->master_stat) & BUSBUSY)
- if (ctrlc())
- return 1;
-
- /* Set Transmit device address */
- writew(chip, &twi->master_addr);
-
- /* Clear the FIFO before starting things */
- writew(XMTFLUSH | RCVFLUSH, &twi->fifo_ctl);
- writew(0, &twi->fifo_ctl);
-
- /* prime the pump */
- if (msg.alen) {
- len = (msg.flags & I2C_M_COMBO) ? msg.alen : msg.alen + len;
- writew(*(msg.abuf++), &twi->xmt_data8);
- --msg.alen;
- } else if (!(msg.flags & I2C_M_READ) && msg.len) {
- writew(*(msg.buf++), &twi->xmt_data8);
- --msg.len;
- }
-
- /* clear int stat */
- writew(-1, &twi->master_stat);
- writew(-1, &twi->int_stat);
- writew(0, &twi->int_mask);
-
- /* Master enable */
- ctl = readw(&twi->master_ctl);
- ctl = (ctl & FAST) | (min(len, 0xff) << 6) | MEN |
- ((msg.flags & I2C_M_READ) ? MDIR : 0);
- writew(ctl, &twi->master_ctl);
-
- /* process the rest */
- ret = wait_for_completion(twi, &msg);
-
- if (ret) {
- ctl = readw(&twi->master_ctl) & ~MEN;
- writew(ctl, &twi->master_ctl);
- ctl = readw(&twi->control) & ~TWI_ENA;
- writew(ctl, &twi->control);
- ctl = readw(&twi->control) | TWI_ENA;
- writew(ctl, &twi->control);
- }
-
- return ret;
-}
-
-static uint adi_i2c_setspeed(struct i2c_adapter *adap, uint speed)
-{
- struct twi_regs *twi = i2c_get_base(adap);
- u16 clkdiv = I2C_SPEED_TO_DUTY(speed);
-
- /* Set TWI interface clock */
- if (clkdiv < I2C_DUTY_MAX || clkdiv > I2C_DUTY_MIN)
- return -1;
- clkdiv = (clkdiv << 8) | (clkdiv & 0xff);
- writew(clkdiv, &twi->clkdiv);
-
- /* Don't turn it on */
- writew(speed > 100000 ? FAST : 0, &twi->master_ctl);
-
- return 0;
-}
-
-static void adi_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
-{
- struct twi_regs *twi = i2c_get_base(adap);
- u16 prescale = ((get_i2c_clk() / 1000 / 1000 + 5) / 10) & 0x7F;
-
- /* Set TWI internal clock as 10MHz */
- writew(prescale, &twi->control);
-
- /* Set TWI interface clock as specified */
- i2c_set_bus_speed(speed);
-
- /* Enable it */
- writew(TWI_ENA | prescale, &twi->control);
-}
-
-static int adi_i2c_read(struct i2c_adapter *adap, uint8_t chip,
- uint addr, int alen, uint8_t *buffer, int len)
-{
- return i2c_transfer(adap, chip, addr, alen, buffer,
- len, alen ? I2C_M_COMBO : I2C_M_READ);
-}
-
-static int adi_i2c_write(struct i2c_adapter *adap, uint8_t chip,
- uint addr, int alen, uint8_t *buffer, int len)
-{
- return i2c_transfer(adap, chip, addr, alen, buffer, len, 0);
-}
-
-static int adi_i2c_probe(struct i2c_adapter *adap, uint8_t chip)
-{
- u8 byte;
- return adi_i2c_read(adap, chip, 0, 0, &byte, 1);
-}
-
-static struct twi_regs *i2c_get_base(struct i2c_adapter *adap)
-{
- switch (adap->hwadapnr) {
-#if CONFIG_SYS_MAX_I2C_BUS > 2
- case 2:
- return (struct twi_regs *)TWI2_CLKDIV;
-#endif
-#if CONFIG_SYS_MAX_I2C_BUS > 1
- case 1:
- return (struct twi_regs *)TWI1_CLKDIV;
-#endif
- case 0:
- return (struct twi_regs *)TWI0_CLKDIV;
-
- default:
- printf("wrong hwadapnr: %d\n", adap->hwadapnr);
- }
-
- return NULL;
-}
-
-U_BOOT_I2C_ADAP_COMPLETE(adi_i2c0, adi_i2c_init, adi_i2c_probe,
- adi_i2c_read, adi_i2c_write,
- adi_i2c_setspeed,
- CONFIG_SYS_I2C_SPEED,
- 0,
- 0)
-
-#if CONFIG_SYS_MAX_I2C_BUS > 1
-U_BOOT_I2C_ADAP_COMPLETE(adi_i2c1, adi_i2c_init, adi_i2c_probe,
- adi_i2c_read, adi_i2c_write,
- adi_i2c_setspeed,
- CONFIG_SYS_I2C_SPEED,
- 0,
- 1)
-#endif
-
-#if CONFIG_SYS_MAX_I2C_BUS > 2
-U_BOOT_I2C_ADAP_COMPLETE(adi_i2c2, adi_i2c_init, adi_i2c_probe,
- adi_i2c_read, adi_i2c_write,
- adi_i2c_setspeed,
- CONFIG_SYS_I2C_SPEED,
- 0,
- 2)
-#endif
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