u-boot/drivers/i2c/s3c24x0_i2c.c

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/*
* (C) Copyright 2002
* David Mueller, ELSOFT AG, d.mueller@elsoft.ch
*
* SPDX-License-Identifier: GPL-2.0+
*/
/* This code should work for both the S3C2400 and the S3C2410
* as they seem to have the same I2C controller inside.
* The different address mapping is handled by the s3c24xx.h files below.
*/
#include <common.h>
#include <fdtdec.h>
#if (defined CONFIG_EXYNOS4 || defined CONFIG_EXYNOS5)
#include <asm/arch/clk.h>
#include <asm/arch/cpu.h>
#include <asm/arch/pinmux.h>
#else
#include <asm/arch/s3c24x0_cpu.h>
#endif
#include <asm/io.h>
#include <i2c.h>
#include "s3c24x0_i2c.h"
#ifdef CONFIG_HARD_I2C
#define I2C_WRITE 0
#define I2C_READ 1
#define I2C_OK 0
#define I2C_NOK 1
#define I2C_NACK 2
#define I2C_NOK_LA 3 /* Lost arbitration */
#define I2C_NOK_TOUT 4 /* time out */
#define I2CSTAT_BSY 0x20 /* Busy bit */
#define I2CSTAT_NACK 0x01 /* Nack bit */
#define I2CCON_ACKGEN 0x80 /* Acknowledge generation */
#define I2CCON_IRPND 0x10 /* Interrupt pending bit */
#define I2C_MODE_MT 0xC0 /* Master Transmit Mode */
#define I2C_MODE_MR 0x80 /* Master Receive Mode */
#define I2C_START_STOP 0x20 /* START / STOP */
#define I2C_TXRX_ENA 0x10 /* I2C Tx/Rx enable */
#define I2C_TIMEOUT 1 /* 1 second */
/*
* For SPL boot some boards need i2c before SDRAM is initialised so force
* variables to live in SRAM
*/
static unsigned int g_current_bus __attribute__((section(".data")));
#ifdef CONFIG_OF_CONTROL
static int i2c_busses __attribute__((section(".data")));
static struct s3c24x0_i2c_bus i2c_bus[CONFIG_MAX_I2C_NUM]
__attribute__((section(".data")));
#endif
#if !(defined CONFIG_EXYNOS4 || defined CONFIG_EXYNOS5)
static int GetI2CSDA(void)
{
struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio();
#ifdef CONFIG_S3C2410
return (readl(&gpio->gpedat) & 0x8000) >> 15;
#endif
#ifdef CONFIG_S3C2400
return (readl(&gpio->pgdat) & 0x0020) >> 5;
#endif
}
static void SetI2CSCL(int x)
{
struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio();
#ifdef CONFIG_S3C2410
writel((readl(&gpio->gpedat) & ~0x4000) |
(x & 1) << 14, &gpio->gpedat);
#endif
#ifdef CONFIG_S3C2400
writel((readl(&gpio->pgdat) & ~0x0040) | (x & 1) << 6, &gpio->pgdat);
#endif
}
#endif
static int WaitForXfer(struct s3c24x0_i2c *i2c)
{
int i;
i = I2C_TIMEOUT * 10000;
while (!(readl(&i2c->iiccon) & I2CCON_IRPND) && (i > 0)) {
udelay(100);
i--;
}
return (readl(&i2c->iiccon) & I2CCON_IRPND) ? I2C_OK : I2C_NOK_TOUT;
}
static int IsACK(struct s3c24x0_i2c *i2c)
{
return !(readl(&i2c->iicstat) & I2CSTAT_NACK);
}
static void ReadWriteByte(struct s3c24x0_i2c *i2c)
{
writel(readl(&i2c->iiccon) & ~I2CCON_IRPND, &i2c->iiccon);
}
static struct s3c24x0_i2c *get_base_i2c(void)
{
#ifdef CONFIG_EXYNOS4
struct s3c24x0_i2c *i2c = (struct s3c24x0_i2c *)(samsung_get_base_i2c()
+ (EXYNOS4_I2C_SPACING
* g_current_bus));
return i2c;
#elif defined CONFIG_EXYNOS5
struct s3c24x0_i2c *i2c = (struct s3c24x0_i2c *)(samsung_get_base_i2c()
+ (EXYNOS5_I2C_SPACING
* g_current_bus));
return i2c;
#else
return s3c24x0_get_base_i2c();
#endif
}
static void i2c_ch_init(struct s3c24x0_i2c *i2c, int speed, int slaveadd)
{
ulong freq, pres = 16, div;
#if (defined CONFIG_EXYNOS4 || defined CONFIG_EXYNOS5)
freq = get_i2c_clk();
#else
freq = get_PCLK();
#endif
/* calculate prescaler and divisor values */
if ((freq / pres / (16 + 1)) > speed)
/* set prescaler to 512 */
pres = 512;
div = 0;
while ((freq / pres / (div + 1)) > speed)
div++;
/* set prescaler, divisor according to freq, also set ACKGEN, IRQ */
writel((div & 0x0F) | 0xA0 | ((pres == 512) ? 0x40 : 0), &i2c->iiccon);
/* init to SLAVE REVEIVE and set slaveaddr */
writel(0, &i2c->iicstat);
writel(slaveadd, &i2c->iicadd);
/* program Master Transmit (and implicit STOP) */
writel(I2C_MODE_MT | I2C_TXRX_ENA, &i2c->iicstat);
}
/*
* MULTI BUS I2C support
*/
#ifdef CONFIG_I2C_MULTI_BUS
int i2c_set_bus_num(unsigned int bus)
{
struct s3c24x0_i2c *i2c;
if ((bus < 0) || (bus >= CONFIG_MAX_I2C_NUM)) {
debug("Bad bus: %d\n", bus);
return -1;
}
g_current_bus = bus;
i2c = get_base_i2c();
i2c_ch_init(i2c, CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
return 0;
}
unsigned int i2c_get_bus_num(void)
{
return g_current_bus;
}
#endif
void i2c_init(int speed, int slaveadd)
{
struct s3c24x0_i2c *i2c;
#if !(defined CONFIG_EXYNOS4 || defined CONFIG_EXYNOS5)
struct s3c24x0_gpio *gpio = s3c24x0_get_base_gpio();
#endif
int i;
/* By default i2c channel 0 is the current bus */
g_current_bus = 0;
i2c = get_base_i2c();
/* wait for some time to give previous transfer a chance to finish */
i = I2C_TIMEOUT * 1000;
while ((readl(&i2c->iicstat) & I2CSTAT_BSY) && (i > 0)) {
udelay(1000);
i--;
}
#if !(defined CONFIG_EXYNOS4 || defined CONFIG_EXYNOS5)
if ((readl(&i2c->iicstat) & I2CSTAT_BSY) || GetI2CSDA() == 0) {
#ifdef CONFIG_S3C2410
ulong old_gpecon = readl(&gpio->gpecon);
#endif
#ifdef CONFIG_S3C2400
ulong old_gpecon = readl(&gpio->pgcon);
#endif
/* bus still busy probably by (most) previously interrupted
transfer */
#ifdef CONFIG_S3C2410
/* set I2CSDA and I2CSCL (GPE15, GPE14) to GPIO */
writel((readl(&gpio->gpecon) & ~0xF0000000) | 0x10000000,
&gpio->gpecon);
#endif
#ifdef CONFIG_S3C2400
/* set I2CSDA and I2CSCL (PG5, PG6) to GPIO */
writel((readl(&gpio->pgcon) & ~0x00003c00) | 0x00001000,
&gpio->pgcon);
#endif
/* toggle I2CSCL until bus idle */
SetI2CSCL(0);
udelay(1000);
i = 10;
while ((i > 0) && (GetI2CSDA() != 1)) {
SetI2CSCL(1);
udelay(1000);
SetI2CSCL(0);
udelay(1000);
i--;
}
SetI2CSCL(1);
udelay(1000);
/* restore pin functions */
#ifdef CONFIG_S3C2410
writel(old_gpecon, &gpio->gpecon);
#endif
#ifdef CONFIG_S3C2400
writel(old_gpecon, &gpio->pgcon);
#endif
}
#endif /* #if !(defined CONFIG_EXYNOS4 || defined CONFIG_EXYNOS5) */
i2c_ch_init(i2c, speed, slaveadd);
}
/*
* cmd_type is 0 for write, 1 for read.
*
* addr_len can take any value from 0-255, it is only limited
* by the char, we could make it larger if needed. If it is
* 0 we skip the address write cycle.
*/
static int i2c_transfer(struct s3c24x0_i2c *i2c,
unsigned char cmd_type,
unsigned char chip,
unsigned char addr[],
unsigned char addr_len,
unsigned char data[],
unsigned short data_len)
{
int i, result;
if (data == 0 || data_len == 0) {
/*Don't support data transfer of no length or to address 0 */
debug("i2c_transfer: bad call\n");
return I2C_NOK;
}
/* Check I2C bus idle */
i = I2C_TIMEOUT * 1000;
while ((readl(&i2c->iicstat) & I2CSTAT_BSY) && (i > 0)) {
udelay(1000);
i--;
}
if (readl(&i2c->iicstat) & I2CSTAT_BSY)
return I2C_NOK_TOUT;
writel(readl(&i2c->iiccon) | I2CCON_ACKGEN, &i2c->iiccon);
result = I2C_OK;
switch (cmd_type) {
case I2C_WRITE:
if (addr && addr_len) {
writel(chip, &i2c->iicds);
/* send START */
writel(I2C_MODE_MT | I2C_TXRX_ENA | I2C_START_STOP,
&i2c->iicstat);
i = 0;
while ((i < addr_len) && (result == I2C_OK)) {
result = WaitForXfer(i2c);
writel(addr[i], &i2c->iicds);
ReadWriteByte(i2c);
i++;
}
i = 0;
while ((i < data_len) && (result == I2C_OK)) {
result = WaitForXfer(i2c);
writel(data[i], &i2c->iicds);
ReadWriteByte(i2c);
i++;
}
} else {
writel(chip, &i2c->iicds);
/* send START */
writel(I2C_MODE_MT | I2C_TXRX_ENA | I2C_START_STOP,
&i2c->iicstat);
i = 0;
while ((i < data_len) && (result == I2C_OK)) {
result = WaitForXfer(i2c);
writel(data[i], &i2c->iicds);
ReadWriteByte(i2c);
i++;
}
}
if (result == I2C_OK)
result = WaitForXfer(i2c);
/* send STOP */
writel(I2C_MODE_MT | I2C_TXRX_ENA, &i2c->iicstat);
ReadWriteByte(i2c);
break;
case I2C_READ:
if (addr && addr_len) {
writel(chip, &i2c->iicds);
/* send START */
writel(I2C_MODE_MT | I2C_TXRX_ENA | I2C_START_STOP,
&i2c->iicstat);
result = WaitForXfer(i2c);
if (IsACK(i2c)) {
i = 0;
while ((i < addr_len) && (result == I2C_OK)) {
writel(addr[i], &i2c->iicds);
ReadWriteByte(i2c);
result = WaitForXfer(i2c);
i++;
}
writel(chip, &i2c->iicds);
/* resend START */
writel(I2C_MODE_MR | I2C_TXRX_ENA |
I2C_START_STOP, &i2c->iicstat);
ReadWriteByte(i2c);
result = WaitForXfer(i2c);
i = 0;
while ((i < data_len) && (result == I2C_OK)) {
/* disable ACK for final READ */
if (i == data_len - 1)
writel(readl(&i2c->iiccon)
& ~I2CCON_ACKGEN,
&i2c->iiccon);
ReadWriteByte(i2c);
result = WaitForXfer(i2c);
data[i] = readl(&i2c->iicds);
i++;
}
} else {
result = I2C_NACK;
}
} else {
writel(chip, &i2c->iicds);
/* send START */
writel(I2C_MODE_MR | I2C_TXRX_ENA | I2C_START_STOP,
&i2c->iicstat);
result = WaitForXfer(i2c);
if (IsACK(i2c)) {
i = 0;
while ((i < data_len) && (result == I2C_OK)) {
/* disable ACK for final READ */
if (i == data_len - 1)
writel(readl(&i2c->iiccon) &
~I2CCON_ACKGEN,
&i2c->iiccon);
ReadWriteByte(i2c);
result = WaitForXfer(i2c);
data[i] = readl(&i2c->iicds);
i++;
}
} else {
result = I2C_NACK;
}
}
/* send STOP */
writel(I2C_MODE_MR | I2C_TXRX_ENA, &i2c->iicstat);
ReadWriteByte(i2c);
break;
default:
debug("i2c_transfer: bad call\n");
result = I2C_NOK;
break;
}
return result;
}
int i2c_probe(uchar chip)
{
struct s3c24x0_i2c *i2c;
uchar buf[1];
i2c = get_base_i2c();
buf[0] = 0;
/*
* What is needed is to send the chip address and verify that the
* address was <ACK>ed (i.e. there was a chip at that address which
* drove the data line low).
*/
return i2c_transfer(i2c, I2C_READ, chip << 1, 0, 0, buf, 1) != I2C_OK;
}
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
struct s3c24x0_i2c *i2c;
uchar xaddr[4];
int ret;
if (alen > 4) {
debug("I2C read: addr len %d not supported\n", alen);
return 1;
}
if (alen > 0) {
xaddr[0] = (addr >> 24) & 0xFF;
xaddr[1] = (addr >> 16) & 0xFF;
xaddr[2] = (addr >> 8) & 0xFF;
xaddr[3] = addr & 0xFF;
}
#ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
/*
* EEPROM chips that implement "address overflow" are ones
* like Catalyst 24WC04/08/16 which has 9/10/11 bits of
* address and the extra bits end up in the "chip address"
* bit slots. This makes a 24WC08 (1Kbyte) chip look like
* four 256 byte chips.
*
* Note that we consider the length of the address field to
* still be one byte because the extra address bits are
* hidden in the chip address.
*/
if (alen > 0)
chip |= ((addr >> (alen * 8)) &
CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
#endif
i2c = get_base_i2c();
ret = i2c_transfer(i2c, I2C_READ, chip << 1, &xaddr[4 - alen], alen,
buffer, len);
if (ret != 0) {
debug("I2c read: failed %d\n", ret);
return 1;
}
return 0;
}
int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
struct s3c24x0_i2c *i2c;
uchar xaddr[4];
if (alen > 4) {
debug("I2C write: addr len %d not supported\n", alen);
return 1;
}
if (alen > 0) {
xaddr[0] = (addr >> 24) & 0xFF;
xaddr[1] = (addr >> 16) & 0xFF;
xaddr[2] = (addr >> 8) & 0xFF;
xaddr[3] = addr & 0xFF;
}
#ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
/*
* EEPROM chips that implement "address overflow" are ones
* like Catalyst 24WC04/08/16 which has 9/10/11 bits of
* address and the extra bits end up in the "chip address"
* bit slots. This makes a 24WC08 (1Kbyte) chip look like
* four 256 byte chips.
*
* Note that we consider the length of the address field to
* still be one byte because the extra address bits are
* hidden in the chip address.
*/
if (alen > 0)
chip |= ((addr >> (alen * 8)) &
CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
#endif
i2c = get_base_i2c();
return (i2c_transfer
(i2c, I2C_WRITE, chip << 1, &xaddr[4 - alen], alen, buffer,
len) != 0);
}
#ifdef CONFIG_OF_CONTROL
void board_i2c_init(const void *blob)
{
int i;
int node_list[CONFIG_MAX_I2C_NUM];
int count;
count = fdtdec_find_aliases_for_id(blob, "i2c",
COMPAT_SAMSUNG_S3C2440_I2C, node_list,
CONFIG_MAX_I2C_NUM);
for (i = 0; i < count; i++) {
struct s3c24x0_i2c_bus *bus;
int node = node_list[i];
if (node <= 0)
continue;
bus = &i2c_bus[i];
bus->regs = (struct s3c24x0_i2c *)
fdtdec_get_addr(blob, node, "reg");
bus->id = pinmux_decode_periph_id(blob, node);
bus->node = node;
bus->bus_num = i2c_busses++;
exynos_pinmux_config(bus->id, 0);
}
}
static struct s3c24x0_i2c_bus *get_bus(unsigned int bus_idx)
{
if (bus_idx < i2c_busses)
return &i2c_bus[bus_idx];
debug("Undefined bus: %d\n", bus_idx);
return NULL;
}
int i2c_get_bus_num_fdt(int node)
{
int i;
for (i = 0; i < i2c_busses; i++) {
if (node == i2c_bus[i].node)
return i;
}
debug("%s: Can't find any matched I2C bus\n", __func__);
return -1;
}
int i2c_reset_port_fdt(const void *blob, int node)
{
struct s3c24x0_i2c_bus *i2c;
int bus;
bus = i2c_get_bus_num_fdt(node);
if (bus < 0) {
debug("could not get bus for node %d\n", node);
return -1;
}
i2c = get_bus(bus);
if (!i2c) {
debug("get_bus() failed for node node %d\n", node);
return -1;
}
i2c_ch_init(i2c->regs, CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
return 0;
}
#endif
#endif /* CONFIG_HARD_I2C */