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u-boot/drivers/i2c/fti2c010.c
Kuo-Jung Su dccacbe019 i2c: fti2c010: fix compiler warning on paddr[] 
This fixes the following compiler warnings:

fti2c010.c: In function 'fti2c010_read':
fti2c010.c:204:8: warning: 'paddr' may be used uninitialized in this function [-Wuninitialized]
fti2c010.c: In function 'fti2c010_write':
fti2c010.c:266:8: warning: 'paddr' may be used uninitialized in this function [-Wuninitialized]

Signed-off-by: Kuo-Jung Su <dantesu@faraday-tech.com>
Cc: Heiko Schocher <hs@denx.de>
2014-01-13 08:18:38 +01:00

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/*
* Faraday I2C Controller
*
* (C) Copyright 2010 Faraday Technology
* Dante Su <dantesu@faraday-tech.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <i2c.h>
#include "fti2c010.h"
#ifndef CONFIG_SYS_I2C_SPEED
#define CONFIG_SYS_I2C_SPEED 5000
#endif
#ifndef CONFIG_SYS_I2C_SLAVE
#define CONFIG_SYS_I2C_SLAVE 0
#endif
#ifndef CONFIG_FTI2C010_CLOCK
#define CONFIG_FTI2C010_CLOCK clk_get_rate("I2C")
#endif
#ifndef CONFIG_FTI2C010_TIMEOUT
#define CONFIG_FTI2C010_TIMEOUT 10 /* ms */
#endif
/* 7-bit dev address + 1-bit read/write */
#define I2C_RD(dev) ((((dev) << 1) & 0xfe) | 1)
#define I2C_WR(dev) (((dev) << 1) & 0xfe)
struct fti2c010_chip {
struct fti2c010_regs *regs;
};
static struct fti2c010_chip chip_list[] = {
{
.regs = (struct fti2c010_regs *)CONFIG_FTI2C010_BASE,
},
#ifdef CONFIG_FTI2C010_BASE1
{
.regs = (struct fti2c010_regs *)CONFIG_FTI2C010_BASE1,
},
#endif
#ifdef CONFIG_FTI2C010_BASE2
{
.regs = (struct fti2c010_regs *)CONFIG_FTI2C010_BASE2,
},
#endif
#ifdef CONFIG_FTI2C010_BASE3
{
.regs = (struct fti2c010_regs *)CONFIG_FTI2C010_BASE3,
},
#endif
};
static int fti2c010_reset(struct fti2c010_chip *chip)
{
ulong ts;
int ret = -1;
struct fti2c010_regs *regs = chip->regs;
writel(CR_I2CRST, &regs->cr);
for (ts = get_timer(0); get_timer(ts) < CONFIG_FTI2C010_TIMEOUT; ) {
if (!(readl(&regs->cr) & CR_I2CRST)) {
ret = 0;
break;
}
}
if (ret)
printf("fti2c010: reset timeout\n");
return ret;
}
static int fti2c010_wait(struct fti2c010_chip *chip, uint32_t mask)
{
int ret = -1;
uint32_t stat, ts;
struct fti2c010_regs *regs = chip->regs;
for (ts = get_timer(0); get_timer(ts) < CONFIG_FTI2C010_TIMEOUT; ) {
stat = readl(&regs->sr);
if ((stat & mask) == mask) {
ret = 0;
break;
}
}
return ret;
}
static unsigned int set_i2c_bus_speed(struct fti2c010_chip *chip,
unsigned int speed)
{
struct fti2c010_regs *regs = chip->regs;
unsigned int clk = CONFIG_FTI2C010_CLOCK;
unsigned int gsr = 0;
unsigned int tsr = 32;
unsigned int div, rate;
for (div = 0; div < 0x3ffff; ++div) {
/* SCLout = PCLK/(2*(COUNT + 2) + GSR) */
rate = clk / (2 * (div + 2) + gsr);
if (rate <= speed)
break;
}
writel(TGSR_GSR(gsr) | TGSR_TSR(tsr), &regs->tgsr);
writel(CDR_DIV(div), &regs->cdr);
return rate;
}
/*
* Initialization, must be called once on start up, may be called
* repeatedly to change the speed and slave addresses.
*/
static void fti2c010_init(struct i2c_adapter *adap, int speed, int slaveaddr)
{
struct fti2c010_chip *chip = chip_list + adap->hwadapnr;
if (adap->init_done)
return;
#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
/* master init */
fti2c010_reset(chip);
set_i2c_bus_speed(chip, speed);
/* slave init, don't care */
#ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT
/* Call board specific i2c bus reset routine AFTER the bus has been
* initialized. Use either this callpoint or i2c_init_board;
* which is called before fti2c010_init operations.
* For details about this problem see doc/I2C_Edge_Conditions.
*/
i2c_board_late_init();
#endif
}
/*
* Probe the given I2C chip address. Returns 0 if a chip responded,
* not 0 on failure.
*/
static int fti2c010_probe(struct i2c_adapter *adap, u8 dev)
{
struct fti2c010_chip *chip = chip_list + adap->hwadapnr;
struct fti2c010_regs *regs = chip->regs;
int ret;
/* 1. Select slave device (7bits Address + 1bit R/W) */
writel(I2C_WR(dev), &regs->dr);
writel(CR_ENABLE | CR_TBEN | CR_START, &regs->cr);
ret = fti2c010_wait(chip, SR_DT);
if (ret)
return ret;
/* 2. Select device register */
writel(0, &regs->dr);
writel(CR_ENABLE | CR_TBEN, &regs->cr);
ret = fti2c010_wait(chip, SR_DT);
return ret;
}
static void to_i2c_addr(u8 *buf, uint32_t addr, int alen)
{
int i, shift;
if (!buf || alen <= 0)
return;
/* MSB first */
i = 0;
shift = (alen - 1) * 8;
while (alen-- > 0) {
buf[i] = (u8)(addr >> shift);
shift -= 8;
}
}
static int fti2c010_read(struct i2c_adapter *adap,
u8 dev, uint addr, int alen, uchar *buf, int len)
{
struct fti2c010_chip *chip = chip_list + adap->hwadapnr;
struct fti2c010_regs *regs = chip->regs;
int ret, pos;
uchar paddr[4] = { 0 };
to_i2c_addr(paddr, addr, alen);
/*
* Phase A. Set register address
*/
/* A.1 Select slave device (7bits Address + 1bit R/W) */
writel(I2C_WR(dev), &regs->dr);
writel(CR_ENABLE | CR_TBEN | CR_START, &regs->cr);
ret = fti2c010_wait(chip, SR_DT);
if (ret)
return ret;
/* A.2 Select device register */
for (pos = 0; pos < alen; ++pos) {
uint32_t ctrl = CR_ENABLE | CR_TBEN;
writel(paddr[pos], &regs->dr);
writel(ctrl, &regs->cr);
ret = fti2c010_wait(chip, SR_DT);
if (ret)
return ret;
}
/*
* Phase B. Get register data
*/
/* B.1 Select slave device (7bits Address + 1bit R/W) */
writel(I2C_RD(dev), &regs->dr);
writel(CR_ENABLE | CR_TBEN | CR_START, &regs->cr);
ret = fti2c010_wait(chip, SR_DT);
if (ret)
return ret;
/* B.2 Get register data */
for (pos = 0; pos < len; ++pos) {
uint32_t ctrl = CR_ENABLE | CR_TBEN;
uint32_t stat = SR_DR;
if (pos == len - 1) {
ctrl |= CR_NAK | CR_STOP;
stat |= SR_ACK;
}
writel(ctrl, &regs->cr);
ret = fti2c010_wait(chip, stat);
if (ret)
break;
buf[pos] = (uchar)(readl(&regs->dr) & 0xFF);
}
return ret;
}
static int fti2c010_write(struct i2c_adapter *adap,
u8 dev, uint addr, int alen, u8 *buf, int len)
{
struct fti2c010_chip *chip = chip_list + adap->hwadapnr;
struct fti2c010_regs *regs = chip->regs;
int ret, pos;
uchar paddr[4] = { 0 };
to_i2c_addr(paddr, addr, alen);
/*
* Phase A. Set register address
*
* A.1 Select slave device (7bits Address + 1bit R/W)
*/
writel(I2C_WR(dev), &regs->dr);
writel(CR_ENABLE | CR_TBEN | CR_START, &regs->cr);
ret = fti2c010_wait(chip, SR_DT);
if (ret)
return ret;
/* A.2 Select device register */
for (pos = 0; pos < alen; ++pos) {
uint32_t ctrl = CR_ENABLE | CR_TBEN;
writel(paddr[pos], &regs->dr);
writel(ctrl, &regs->cr);
ret = fti2c010_wait(chip, SR_DT);
if (ret)
return ret;
}
/*
* Phase B. Set register data
*/
for (pos = 0; pos < len; ++pos) {
uint32_t ctrl = CR_ENABLE | CR_TBEN;
if (pos == len - 1)
ctrl |= CR_STOP;
writel(buf[pos], &regs->dr);
writel(ctrl, &regs->cr);
ret = fti2c010_wait(chip, SR_DT);
if (ret)
break;
}
return ret;
}
static unsigned int fti2c010_set_bus_speed(struct i2c_adapter *adap,
unsigned int speed)
{
struct fti2c010_chip *chip = chip_list + adap->hwadapnr;
int ret;
fti2c010_reset(chip);
ret = set_i2c_bus_speed(chip, speed);
return ret;
}
/*
* Register i2c adapters
*/
U_BOOT_I2C_ADAP_COMPLETE(i2c_0, fti2c010_init, fti2c010_probe, fti2c010_read,
fti2c010_write, fti2c010_set_bus_speed,
CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE,
0)
#ifdef CONFIG_FTI2C010_BASE1
U_BOOT_I2C_ADAP_COMPLETE(i2c_1, fti2c010_init, fti2c010_probe, fti2c010_read,
fti2c010_write, fti2c010_set_bus_speed,
CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE,
1)
#endif
#ifdef CONFIG_FTI2C010_BASE2
U_BOOT_I2C_ADAP_COMPLETE(i2c_2, fti2c010_init, fti2c010_probe, fti2c010_read,
fti2c010_write, fti2c010_set_bus_speed,
CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE,
2)
#endif
#ifdef CONFIG_FTI2C010_BASE3
U_BOOT_I2C_ADAP_COMPLETE(i2c_3, fti2c010_init, fti2c010_probe, fti2c010_read,
fti2c010_write, fti2c010_set_bus_speed,
CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE,
3)
#endif
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