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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 */
/* HSI2C specific register description */
/* I2C_CTL Register bits */
#define HSI2C_FUNC_MODE_I2C (1u << 0)
#define HSI2C_MASTER (1u << 3)
#define HSI2C_RXCHON (1u << 6) /* Write/Send */
#define HSI2C_TXCHON (1u << 7) /* Read/Receive */
#define HSI2C_SW_RST (1u << 31)
/* I2C_FIFO_CTL Register bits */
#define HSI2C_RXFIFO_EN (1u << 0)
#define HSI2C_TXFIFO_EN (1u << 1)
#define HSI2C_TXFIFO_TRIGGER_LEVEL (0x20 << 16)
#define HSI2C_RXFIFO_TRIGGER_LEVEL (0x20 << 4)
/* I2C_TRAILING_CTL Register bits */
#define HSI2C_TRAILING_COUNT (0xff)
/* I2C_INT_EN Register bits */
#define HSI2C_TX_UNDERRUN_EN (1u << 2)
#define HSI2C_TX_OVERRUN_EN (1u << 3)
#define HSI2C_RX_UNDERRUN_EN (1u << 4)
#define HSI2C_RX_OVERRUN_EN (1u << 5)
#define HSI2C_INT_TRAILING_EN (1u << 6)
#define HSI2C_INT_I2C_EN (1u << 9)
#define HSI2C_INT_ERROR_MASK (HSI2C_TX_UNDERRUN_EN |\
HSI2C_TX_OVERRUN_EN |\
HSI2C_RX_UNDERRUN_EN |\
HSI2C_RX_OVERRUN_EN |\
HSI2C_INT_TRAILING_EN)
/* I2C_CONF Register bits */
#define HSI2C_AUTO_MODE (1u << 31)
#define HSI2C_10BIT_ADDR_MODE (1u << 30)
#define HSI2C_HS_MODE (1u << 29)
/* I2C_AUTO_CONF Register bits */
#define HSI2C_READ_WRITE (1u << 16)
#define HSI2C_STOP_AFTER_TRANS (1u << 17)
#define HSI2C_MASTER_RUN (1u << 31)
/* I2C_TIMEOUT Register bits */
#define HSI2C_TIMEOUT_EN (1u << 31)
/* I2C_TRANS_STATUS register bits */
#define HSI2C_MASTER_BUSY (1u << 17)
#define HSI2C_SLAVE_BUSY (1u << 16)
#define HSI2C_TIMEOUT_AUTO (1u << 4)
#define HSI2C_NO_DEV (1u << 3)
#define HSI2C_NO_DEV_ACK (1u << 2)
#define HSI2C_TRANS_ABORT (1u << 1)
#define HSI2C_TRANS_SUCCESS (1u << 0)
#define HSI2C_TRANS_ERROR_MASK (HSI2C_TIMEOUT_AUTO |\
HSI2C_NO_DEV | HSI2C_NO_DEV_ACK |\
HSI2C_TRANS_ABORT)
#define HSI2C_TRANS_FINISHED_MASK (HSI2C_TRANS_ERROR_MASK | HSI2C_TRANS_SUCCESS)
/* I2C_FIFO_STAT Register bits */
#define HSI2C_RX_FIFO_EMPTY (1u << 24)
#define HSI2C_RX_FIFO_FULL (1u << 23)
#define HSI2C_TX_FIFO_EMPTY (1u << 8)
#define HSI2C_TX_FIFO_FULL (1u << 7)
#define HSI2C_RX_FIFO_LEVEL(x) (((x) >> 16) & 0x7f)
#define HSI2C_TX_FIFO_LEVEL(x) ((x) & 0x7f)
#define HSI2C_SLV_ADDR_MAS(x) ((x & 0x3ff) << 10)
/* S3C I2C Controller bits */
#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_MS 1000 /* 1 second */
#define HSI2C_TIMEOUT_US 100000 /* 100 ms, finer granularity */
/* To support VCMA9 boards and other who dont define max_i2c_num */
#ifndef CONFIG_MAX_I2C_NUM
#define CONFIG_MAX_I2C_NUM 1
#endif
/*
* 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")));
static struct s3c24x0_i2c_bus i2c_bus[CONFIG_MAX_I2C_NUM]
__attribute__((section(".data")));
/**
* Get a pointer to the given bus index
*
* @bus_idx: Bus index to look up
* @return pointer to bus, or NULL if invalid or not available
*/
static struct s3c24x0_i2c_bus *get_bus(unsigned int bus_idx)
{
if (bus_idx < ARRAY_SIZE(i2c_bus)) {
struct s3c24x0_i2c_bus *bus;
bus = &i2c_bus[bus_idx];
if (bus->active)
return bus;
}
debug("Undefined bus: %d\n", bus_idx);
return NULL;
}
#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
/*
* Wait til the byte transfer is completed.
*
* @param i2c- pointer to the appropriate i2c register bank.
* @return I2C_OK, if transmission was ACKED
* I2C_NACK, if transmission was NACKED
* I2C_NOK_TIMEOUT, if transaction did not complete in I2C_TIMEOUT_MS
*/
static int WaitForXfer(struct s3c24x0_i2c *i2c)
{
ulong start_time = get_timer(0);
do {
if (readl(&i2c->iiccon) & I2CCON_IRPND)
return (readl(&i2c->iicstat) & I2CSTAT_NACK) ?
I2C_NACK : I2C_OK;
} while (get_timer(start_time) < I2C_TIMEOUT_MS);
return I2C_NOK_TOUT;
}
/*
* Wait for transfer completion.
*
* This function reads the interrupt status register waiting for the INT_I2C
* bit to be set, which indicates copletion of a transaction.
*
* @param i2c: pointer to the appropriate register bank
*
* @return: I2C_OK in case of successful completion, I2C_NOK_TIMEOUT in case
* the status bits do not get set in time, or an approrpiate error
* value in case of transfer errors.
*/
static int hsi2c_wait_for_trx(struct exynos5_hsi2c *i2c)
{
int i = HSI2C_TIMEOUT_US;
while (i-- > 0) {
u32 int_status = readl(&i2c->usi_int_stat);
if (int_status & HSI2C_INT_I2C_EN) {
u32 trans_status = readl(&i2c->usi_trans_status);
/* Deassert pending interrupt. */
writel(int_status, &i2c->usi_int_stat);
if (trans_status & HSI2C_NO_DEV_ACK) {
debug("%s: no ACK from device\n", __func__);
return I2C_NACK;
}
if (trans_status & HSI2C_NO_DEV) {
debug("%s: no device\n", __func__);
return I2C_NOK;
}
if (trans_status & HSI2C_TRANS_ABORT) {
debug("%s: arbitration lost\n", __func__);
return I2C_NOK_LA;
}
if (trans_status & HSI2C_TIMEOUT_AUTO) {
debug("%s: device timed out\n", __func__);
return I2C_NOK_TOUT;
}
return I2C_OK;
}
udelay(1);
}
debug("%s: transaction timeout!\n", __func__);
return I2C_NOK_TOUT;
}
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);
}
#ifdef CONFIG_I2C_MULTI_BUS
static int hsi2c_get_clk_details(struct s3c24x0_i2c_bus *i2c_bus)
{
struct exynos5_hsi2c *hsregs = i2c_bus->hsregs;
ulong clkin;
unsigned int op_clk = i2c_bus->clock_frequency;
unsigned int i = 0, utemp0 = 0, utemp1 = 0;
unsigned int t_ftl_cycle;
#if defined CONFIG_EXYNOS5
clkin = get_i2c_clk();
#endif
/* FPCLK / FI2C =
* (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE
* uTemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2)
* uTemp1 = (TSCLK_L + TSCLK_H + 2)
* uTemp2 = TSCLK_L + TSCLK_H
*/
t_ftl_cycle = (readl(&hsregs->usi_conf) >> 16) & 0x7;
utemp0 = (clkin / op_clk) - 8 - 2 * t_ftl_cycle;
/* CLK_DIV max is 256 */
for (i = 0; i < 256; i++) {
utemp1 = utemp0 / (i + 1);
if ((utemp1 < 512) && (utemp1 > 4)) {
i2c_bus->clk_cycle = utemp1 - 2;
i2c_bus->clk_div = i;
return 0;
}
}
return -1;
}
#endif
static void hsi2c_ch_init(struct s3c24x0_i2c_bus *i2c_bus)
{
struct exynos5_hsi2c *hsregs = i2c_bus->hsregs;
unsigned int t_sr_release;
unsigned int n_clkdiv;
unsigned int t_start_su, t_start_hd;
unsigned int t_stop_su;
unsigned int t_data_su, t_data_hd;
unsigned int t_scl_l, t_scl_h;
u32 i2c_timing_s1;
u32 i2c_timing_s2;
u32 i2c_timing_s3;
u32 i2c_timing_sla;
n_clkdiv = i2c_bus->clk_div;
t_scl_l = i2c_bus->clk_cycle / 2;
t_scl_h = i2c_bus->clk_cycle / 2;
t_start_su = t_scl_l;
t_start_hd = t_scl_l;
t_stop_su = t_scl_l;
t_data_su = t_scl_l / 2;
t_data_hd = t_scl_l / 2;
t_sr_release = i2c_bus->clk_cycle;
i2c_timing_s1 = t_start_su << 24 | t_start_hd << 16 | t_stop_su << 8;
i2c_timing_s2 = t_data_su << 24 | t_scl_l << 8 | t_scl_h << 0;
i2c_timing_s3 = n_clkdiv << 16 | t_sr_release << 0;
i2c_timing_sla = t_data_hd << 0;
writel(HSI2C_TRAILING_COUNT, &hsregs->usi_trailing_ctl);
/* Clear to enable Timeout */
clrsetbits_le32(&hsregs->usi_timeout, HSI2C_TIMEOUT_EN, 0);
/* set AUTO mode */
writel(readl(&hsregs->usi_conf) | HSI2C_AUTO_MODE, &hsregs->usi_conf);
/* Enable completion conditions' reporting. */
writel(HSI2C_INT_I2C_EN, &hsregs->usi_int_en);
/* Enable FIFOs */
writel(HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN, &hsregs->usi_fifo_ctl);
/* Currently operating in Fast speed mode. */
writel(i2c_timing_s1, &hsregs->usi_timing_fs1);
writel(i2c_timing_s2, &hsregs->usi_timing_fs2);
writel(i2c_timing_s3, &hsregs->usi_timing_fs3);
writel(i2c_timing_sla, &hsregs->usi_timing_sla);
}
/* SW reset for the high speed bus */
static void exynos5_i2c_reset(struct s3c24x0_i2c_bus *i2c_bus)
{
struct exynos5_hsi2c *i2c = i2c_bus->hsregs;
u32 i2c_ctl;
/* Set and clear the bit for reset */
i2c_ctl = readl(&i2c->usi_ctl);
i2c_ctl |= HSI2C_SW_RST;
writel(i2c_ctl, &i2c->usi_ctl);
i2c_ctl = readl(&i2c->usi_ctl);
i2c_ctl &= ~HSI2C_SW_RST;
writel(i2c_ctl, &i2c->usi_ctl);
/* Initialize the configure registers */
hsi2c_ch_init(i2c_bus);
}
/*
* MULTI BUS I2C support
*/
#ifdef CONFIG_I2C_MULTI_BUS
int i2c_set_bus_num(unsigned int bus)
{
struct s3c24x0_i2c_bus *i2c_bus;
i2c_bus = get_bus(bus);
if (!i2c_bus)
return -1;
g_current_bus = bus;
if (i2c_bus->is_highspeed) {
if (hsi2c_get_clk_details(i2c_bus))
return -1;
hsi2c_ch_init(i2c_bus);
} else {
i2c_ch_init(i2c_bus->regs, i2c_bus->clock_frequency,
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
ulong start_time = get_timer(0);
/* By default i2c channel 0 is the current bus */
g_current_bus = 0;
i2c = get_base_i2c();
/*
* In case the previous transfer is still going, wait to give it a
* chance to finish.
*/
while (readl(&i2c->iicstat) & I2CSTAT_BSY) {
if (get_timer(start_time) > I2C_TIMEOUT_MS) {
printf("%s: I2C bus busy for %p\n", __func__,
&i2c->iicstat);
return;
}
}
#if !(defined CONFIG_EXYNOS4 || defined CONFIG_EXYNOS5)
int i;
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);
}
/*
* Poll the appropriate bit of the fifo status register until the interface is
* ready to process the next byte or timeout expires.
*
* In addition to the FIFO status register this function also polls the
* interrupt status register to be able to detect unexpected transaction
* completion.
*
* When FIFO is ready to process the next byte, this function returns I2C_OK.
* If in course of polling the INT_I2C assertion is detected, the function
* returns I2C_NOK. If timeout happens before any of the above conditions is
* met - the function returns I2C_NOK_TOUT;
* @param i2c: pointer to the appropriate i2c register bank.
* @param rx_transfer: set to True if the receive transaction is in progress.
* @return: as described above.
*/
static unsigned hsi2c_poll_fifo(struct exynos5_hsi2c *i2c, bool rx_transfer)
{
u32 fifo_bit = rx_transfer ? HSI2C_RX_FIFO_EMPTY : HSI2C_TX_FIFO_FULL;
int i = HSI2C_TIMEOUT_US;
while (readl(&i2c->usi_fifo_stat) & fifo_bit) {
if (readl(&i2c->usi_int_stat) & HSI2C_INT_I2C_EN) {
/*
* There is a chance that assertion of
* HSI2C_INT_I2C_EN and deassertion of
* HSI2C_RX_FIFO_EMPTY happen simultaneously. Let's
* give FIFO status priority and check it one more
* time before reporting interrupt. The interrupt will
* be reported next time this function is called.
*/
if (rx_transfer &&
!(readl(&i2c->usi_fifo_stat) & fifo_bit))
break;
return I2C_NOK;
}
if (!i--) {
debug("%s: FIFO polling timeout!\n", __func__);
return I2C_NOK_TOUT;
}
udelay(1);
}
return I2C_OK;
}
/*
* Preapre hsi2c transaction, either read or write.
*
* Set up transfer as described in section 27.5.1.2 'I2C Channel Auto Mode' of
* the 5420 UM.
*
* @param i2c: pointer to the appropriate i2c register bank.
* @param chip: slave address on the i2c bus (with read/write bit exlcuded)
* @param len: number of bytes expected to be sent or received
* @param rx_transfer: set to true for receive transactions
* @param: issue_stop: set to true if i2c stop condition should be generated
* after this transaction.
* @return: I2C_NOK_TOUT in case the bus remained busy for HSI2C_TIMEOUT_US,
* I2C_OK otherwise.
*/
static int hsi2c_prepare_transaction(struct exynos5_hsi2c *i2c,
u8 chip,
u16 len,
bool rx_transfer,
bool issue_stop)
{
u32 conf;
conf = len | HSI2C_MASTER_RUN;
if (issue_stop)
conf |= HSI2C_STOP_AFTER_TRANS;
/* Clear to enable Timeout */
writel(readl(&i2c->usi_timeout) & ~HSI2C_TIMEOUT_EN, &i2c->usi_timeout);
/* Set slave address */
writel(HSI2C_SLV_ADDR_MAS(chip), &i2c->i2c_addr);
if (rx_transfer) {
/* i2c master, read transaction */
writel((HSI2C_RXCHON | HSI2C_FUNC_MODE_I2C | HSI2C_MASTER),
&i2c->usi_ctl);
/* read up to len bytes, stop after transaction is finished */
writel(conf | HSI2C_READ_WRITE, &i2c->usi_auto_conf);
} else {
/* i2c master, write transaction */
writel((HSI2C_TXCHON | HSI2C_FUNC_MODE_I2C | HSI2C_MASTER),
&i2c->usi_ctl);
/* write up to len bytes, stop after transaction is finished */
writel(conf, &i2c->usi_auto_conf);
}
/* Reset all pending interrupt status bits we care about, if any */
writel(HSI2C_INT_I2C_EN, &i2c->usi_int_stat);
return I2C_OK;
}
/*
* Wait while i2c bus is settling down (mostly stop gets completed).
*/
static int hsi2c_wait_while_busy(struct exynos5_hsi2c *i2c)
{
int i = HSI2C_TIMEOUT_US;
while (readl(&i2c->usi_trans_status) & HSI2C_MASTER_BUSY) {
if (!i--) {
debug("%s: bus busy\n", __func__);
return I2C_NOK_TOUT;
}
udelay(1);
}
return I2C_OK;
}
static int hsi2c_write(struct exynos5_hsi2c *i2c,
unsigned char chip,
unsigned char addr[],
unsigned char alen,
unsigned char data[],
unsigned short len,
bool issue_stop)
{
int i, rv = 0;
if (!(len + alen)) {
/* Writes of zero length not supported in auto mode. */
debug("%s: zero length writes not supported\n", __func__);
return I2C_NOK;
}
rv = hsi2c_prepare_transaction
(i2c, chip, len + alen, false, issue_stop);
if (rv != I2C_OK)
return rv;
/* Move address, if any, and the data, if any, into the FIFO. */
for (i = 0; i < alen; i++) {
rv = hsi2c_poll_fifo(i2c, false);
if (rv != I2C_OK) {
debug("%s: address write failed\n", __func__);
goto write_error;
}
writel(addr[i], &i2c->usi_txdata);
}
for (i = 0; i < len; i++) {
rv = hsi2c_poll_fifo(i2c, false);
if (rv != I2C_OK) {
debug("%s: data write failed\n", __func__);
goto write_error;
}
writel(data[i], &i2c->usi_txdata);
}
rv = hsi2c_wait_for_trx(i2c);
write_error:
if (issue_stop) {
int tmp_ret = hsi2c_wait_while_busy(i2c);
if (rv == I2C_OK)
rv = tmp_ret;
}
writel(HSI2C_FUNC_MODE_I2C, &i2c->usi_ctl); /* done */
return rv;
}
static int hsi2c_read(struct exynos5_hsi2c *i2c,
unsigned char chip,
unsigned char addr[],
unsigned char alen,
unsigned char data[],
unsigned short len)
{
int i, rv, tmp_ret;
bool drop_data = false;
if (!len) {
/* Reads of zero length not supported in auto mode. */
debug("%s: zero length read adjusted\n", __func__);
drop_data = true;
len = 1;
}
if (alen) {
/* Internal register adress needs to be written first. */
rv = hsi2c_write(i2c, chip, addr, alen, NULL, 0, false);
if (rv != I2C_OK)
return rv;
}
rv = hsi2c_prepare_transaction(i2c, chip, len, true, true);
if (rv != I2C_OK)
return rv;
for (i = 0; i < len; i++) {
rv = hsi2c_poll_fifo(i2c, true);
if (rv != I2C_OK)
goto read_err;
if (drop_data)
continue;
data[i] = readl(&i2c->usi_rxdata);
}
rv = hsi2c_wait_for_trx(i2c);
read_err:
tmp_ret = hsi2c_wait_while_busy(i2c);
if (rv == I2C_OK)
rv = tmp_ret;
writel(HSI2C_FUNC_MODE_I2C, &i2c->usi_ctl); /* done */
return rv;
}
/*
* 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 = 0, result;
ulong start_time = get_timer(0);
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;
}
while (readl(&i2c->iicstat) & I2CSTAT_BSY) {
if (get_timer(start_time) > I2C_TIMEOUT_MS)
return I2C_NOK_TOUT;
}
writel(readl(&i2c->iiccon) | I2CCON_ACKGEN, &i2c->iiccon);
/* Get the slave chip address going */
writel(chip, &i2c->iicds);
if ((cmd_type == I2C_WRITE) || (addr && addr_len))
writel(I2C_MODE_MT | I2C_TXRX_ENA | I2C_START_STOP,
&i2c->iicstat);
else
writel(I2C_MODE_MR | I2C_TXRX_ENA | I2C_START_STOP,
&i2c->iicstat);
/* Wait for chip address to transmit. */
result = WaitForXfer(i2c);
if (result != I2C_OK)
goto bailout;
/* If register address needs to be transmitted - do it now. */
if (addr && addr_len) {
while ((i < addr_len) && (result == I2C_OK)) {
writel(addr[i++], &i2c->iicds);
ReadWriteByte(i2c);
result = WaitForXfer(i2c);
}
i = 0;
if (result != I2C_OK)
goto bailout;
}
switch (cmd_type) {
case I2C_WRITE:
while ((i < data_len) && (result == I2C_OK)) {
writel(data[i++], &i2c->iicds);
ReadWriteByte(i2c);
result = WaitForXfer(i2c);
}
break;
case I2C_READ:
if (addr && addr_len) {
/*
* Register address has been sent, now send slave chip
* address again to start the actual read transaction.
*/
writel(chip, &i2c->iicds);
/* Generate a re-START. */
writel(I2C_MODE_MR | I2C_TXRX_ENA | I2C_START_STOP,
&i2c->iicstat);
ReadWriteByte(i2c);
result = WaitForXfer(i2c);
if (result != I2C_OK)
goto bailout;
}
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);
}
if (result == I2C_NACK)
result = I2C_OK; /* Normal terminated read. */
break;
default:
debug("i2c_transfer: bad call\n");
result = I2C_NOK;
break;
}
bailout:
/* Send STOP. */
writel(I2C_MODE_MR | I2C_TXRX_ENA, &i2c->iicstat);
ReadWriteByte(i2c);
return result;
}
int i2c_probe(uchar chip)
{
struct s3c24x0_i2c_bus *i2c_bus;
uchar buf[1];
int ret;
i2c_bus = get_bus(g_current_bus);
if (!i2c_bus)
return -1;
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).
*/
if (i2c_bus->is_highspeed) {
ret = hsi2c_read(i2c_bus->hsregs,
chip, 0, 0, buf, 1);
} else {
ret = i2c_transfer(i2c_bus->regs,
I2C_READ, chip << 1, 0, 0, buf, 1);
}
return ret != I2C_OK;
}
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
struct s3c24x0_i2c_bus *i2c_bus;
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_bus = get_bus(g_current_bus);
if (!i2c_bus)
return -1;
if (i2c_bus->is_highspeed)
ret = hsi2c_read(i2c_bus->hsregs, chip, &xaddr[4 - alen],
alen, buffer, len);
else
ret = i2c_transfer(i2c_bus->regs, I2C_READ, chip << 1,
&xaddr[4 - alen], alen, buffer, len);
if (ret) {
if (i2c_bus->is_highspeed)
exynos5_i2c_reset(i2c_bus);
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_bus *i2c_bus;
uchar xaddr[4];
int ret;
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_bus = get_bus(g_current_bus);
if (!i2c_bus)
return -1;
if (i2c_bus->is_highspeed)
ret = hsi2c_write(i2c_bus->hsregs, chip, &xaddr[4 - alen],
alen, buffer, len, true);
else
ret = i2c_transfer(i2c_bus->regs, I2C_WRITE, chip << 1,
&xaddr[4 - alen], alen, buffer, len);
if (ret != 0) {
if (i2c_bus->is_highspeed)
exynos5_i2c_reset(i2c_bus);
return 1;
} else {
return 0;
}
}
#ifdef CONFIG_OF_CONTROL
static void process_nodes(const void *blob, int node_list[], int count,
int is_highspeed)
{
struct s3c24x0_i2c_bus *bus;
int i;
for (i = 0; i < count; i++) {
int node = node_list[i];
if (node <= 0)
continue;
bus = &i2c_bus[i];
bus->active = true;
bus->is_highspeed = is_highspeed;
if (is_highspeed)
bus->hsregs = (struct exynos5_hsi2c *)
fdtdec_get_addr(blob, node, "reg");
else
bus->regs = (struct s3c24x0_i2c *)
fdtdec_get_addr(blob, node, "reg");
bus->id = pinmux_decode_periph_id(blob, node);
bus->clock_frequency = fdtdec_get_int(blob, node,
"clock-frequency",
CONFIG_SYS_I2C_SPEED);
bus->node = node;
bus->bus_num = i;
exynos_pinmux_config(bus->id, 0);
/* Mark position as used */
node_list[i] = -1;
}
}
void board_i2c_init(const void *blob)
{
int node_list[CONFIG_MAX_I2C_NUM];
int count;
/* First get the normal i2c ports */
count = fdtdec_find_aliases_for_id(blob, "i2c",
COMPAT_SAMSUNG_S3C2440_I2C, node_list,
CONFIG_MAX_I2C_NUM);
process_nodes(blob, node_list, count, 0);
/* Now look for high speed i2c ports */
count = fdtdec_find_aliases_for_id(blob, "i2c",
COMPAT_SAMSUNG_EXYNOS5_I2C, node_list,
CONFIG_MAX_I2C_NUM);
process_nodes(blob, node_list, count, 1);
}
int i2c_get_bus_num_fdt(int node)
{
int i;
for (i = 0; i < ARRAY_SIZE(i2c_bus); i++) {
if (node == i2c_bus[i].node)
return i;
}
debug("%s: Can't find any matched I2C bus\n", __func__);
return -1;
}
#ifdef CONFIG_I2C_MULTI_BUS
int i2c_reset_port_fdt(const void *blob, int node)
{
struct s3c24x0_i2c_bus *i2c_bus;
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_bus = get_bus(bus);
if (!i2c_bus) {
debug("get_bus() failed for node node %d\n", node);
return -1;
}
if (i2c_bus->is_highspeed) {
if (hsi2c_get_clk_details(i2c_bus))
return -1;
hsi2c_ch_init(i2c_bus);
} else {
i2c_ch_init(i2c_bus->regs, i2c_bus->clock_frequency,
CONFIG_SYS_I2C_SLAVE);
}
return 0;
}
#endif
#endif
#endif /* CONFIG_HARD_I2C */
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