u-boot/drivers/i2c/designware_i2c.c

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/*
* (C) Copyright 2009
* Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include "designware_i2c.h"
#include <i2c.h>
#ifdef CONFIG_I2C_MULTI_BUS
static unsigned int bus_initialized[CONFIG_SYS_I2C_BUS_MAX];
static unsigned int current_bus = 0;
#endif
static struct i2c_regs *i2c_regs_p =
(struct i2c_regs *)CONFIG_SYS_I2C_BASE;
/*
* set_speed - Set the i2c speed mode (standard, high, fast)
* @i2c_spd: required i2c speed mode
*
* Set the i2c speed mode (standard, high, fast)
*/
static void set_speed(int i2c_spd)
{
unsigned int cntl;
unsigned int hcnt, lcnt;
unsigned int enbl;
/* to set speed cltr must be disabled */
enbl = readl(&i2c_regs_p->ic_enable);
enbl &= ~IC_ENABLE_0B;
writel(enbl, &i2c_regs_p->ic_enable);
cntl = (readl(&i2c_regs_p->ic_con) & (~IC_CON_SPD_MSK));
switch (i2c_spd) {
case IC_SPEED_MODE_MAX:
cntl |= IC_CON_SPD_HS;
hcnt = (IC_CLK * MIN_HS_SCL_HIGHTIME) / NANO_TO_MICRO;
writel(hcnt, &i2c_regs_p->ic_hs_scl_hcnt);
lcnt = (IC_CLK * MIN_HS_SCL_LOWTIME) / NANO_TO_MICRO;
writel(lcnt, &i2c_regs_p->ic_hs_scl_lcnt);
break;
case IC_SPEED_MODE_STANDARD:
cntl |= IC_CON_SPD_SS;
hcnt = (IC_CLK * MIN_SS_SCL_HIGHTIME) / NANO_TO_MICRO;
writel(hcnt, &i2c_regs_p->ic_ss_scl_hcnt);
lcnt = (IC_CLK * MIN_SS_SCL_LOWTIME) / NANO_TO_MICRO;
writel(lcnt, &i2c_regs_p->ic_ss_scl_lcnt);
break;
case IC_SPEED_MODE_FAST:
default:
cntl |= IC_CON_SPD_FS;
hcnt = (IC_CLK * MIN_FS_SCL_HIGHTIME) / NANO_TO_MICRO;
writel(hcnt, &i2c_regs_p->ic_fs_scl_hcnt);
lcnt = (IC_CLK * MIN_FS_SCL_LOWTIME) / NANO_TO_MICRO;
writel(lcnt, &i2c_regs_p->ic_fs_scl_lcnt);
break;
}
writel(cntl, &i2c_regs_p->ic_con);
/* Enable back i2c now speed set */
enbl |= IC_ENABLE_0B;
writel(enbl, &i2c_regs_p->ic_enable);
}
/*
* i2c_set_bus_speed - Set the i2c speed
* @speed: required i2c speed
*
* Set the i2c speed.
*/
int i2c_set_bus_speed(unsigned int speed)
{
int i2c_spd;
if (speed >= I2C_MAX_SPEED)
i2c_spd = IC_SPEED_MODE_MAX;
else if (speed >= I2C_FAST_SPEED)
i2c_spd = IC_SPEED_MODE_FAST;
else
i2c_spd = IC_SPEED_MODE_STANDARD;
set_speed(i2c_spd);
return i2c_spd;
}
/*
* i2c_get_bus_speed - Gets the i2c speed
*
* Gets the i2c speed.
*/
unsigned int i2c_get_bus_speed(void)
{
u32 cntl;
cntl = (readl(&i2c_regs_p->ic_con) & IC_CON_SPD_MSK);
if (cntl == IC_CON_SPD_HS)
return I2C_MAX_SPEED;
else if (cntl == IC_CON_SPD_FS)
return I2C_FAST_SPEED;
else if (cntl == IC_CON_SPD_SS)
return I2C_STANDARD_SPEED;
return 0;
}
/*
* i2c_init - Init function
* @speed: required i2c speed
* @slaveadd: slave address for the device
*
* Initialization function.
*/
void i2c_init(int speed, int slaveadd)
{
unsigned int enbl;
/* Disable i2c */
enbl = readl(&i2c_regs_p->ic_enable);
enbl &= ~IC_ENABLE_0B;
writel(enbl, &i2c_regs_p->ic_enable);
writel((IC_CON_SD | IC_CON_SPD_FS | IC_CON_MM), &i2c_regs_p->ic_con);
writel(IC_RX_TL, &i2c_regs_p->ic_rx_tl);
writel(IC_TX_TL, &i2c_regs_p->ic_tx_tl);
i2c_set_bus_speed(speed);
writel(IC_STOP_DET, &i2c_regs_p->ic_intr_mask);
writel(slaveadd, &i2c_regs_p->ic_sar);
/* Enable i2c */
enbl = readl(&i2c_regs_p->ic_enable);
enbl |= IC_ENABLE_0B;
writel(enbl, &i2c_regs_p->ic_enable);
#ifdef CONFIG_I2C_MULTI_BUS
bus_initialized[current_bus] = 1;
#endif
}
/*
* i2c_setaddress - Sets the target slave address
* @i2c_addr: target i2c address
*
* Sets the target slave address.
*/
static void i2c_setaddress(unsigned int i2c_addr)
{
unsigned int enbl;
/* Disable i2c */
enbl = readl(&i2c_regs_p->ic_enable);
enbl &= ~IC_ENABLE_0B;
writel(enbl, &i2c_regs_p->ic_enable);
writel(i2c_addr, &i2c_regs_p->ic_tar);
/* Enable i2c */
enbl = readl(&i2c_regs_p->ic_enable);
enbl |= IC_ENABLE_0B;
writel(enbl, &i2c_regs_p->ic_enable);
}
/*
* i2c_flush_rxfifo - Flushes the i2c RX FIFO
*
* Flushes the i2c RX FIFO
*/
static void i2c_flush_rxfifo(void)
{
while (readl(&i2c_regs_p->ic_status) & IC_STATUS_RFNE)
readl(&i2c_regs_p->ic_cmd_data);
}
/*
* i2c_wait_for_bb - Waits for bus busy
*
* Waits for bus busy
*/
static int i2c_wait_for_bb(void)
{
unsigned long start_time_bb = get_timer(0);
while ((readl(&i2c_regs_p->ic_status) & IC_STATUS_MA) ||
!(readl(&i2c_regs_p->ic_status) & IC_STATUS_TFE)) {
/* Evaluate timeout */
if (get_timer(start_time_bb) > (unsigned long)(I2C_BYTE_TO_BB))
return 1;
}
return 0;
}
static int i2c_xfer_init(uchar chip, uint addr, int alen)
{
if (i2c_wait_for_bb())
return 1;
i2c_setaddress(chip);
while (alen) {
alen--;
/* high byte address going out first */
writel((addr >> (alen * 8)) & 0xff,
&i2c_regs_p->ic_cmd_data);
}
return 0;
}
static int i2c_xfer_finish(void)
{
ulong start_stop_det = get_timer(0);
while (1) {
if ((readl(&i2c_regs_p->ic_raw_intr_stat) & IC_STOP_DET)) {
readl(&i2c_regs_p->ic_clr_stop_det);
break;
} else if (get_timer(start_stop_det) > I2C_STOPDET_TO) {
break;
}
}
if (i2c_wait_for_bb()) {
printf("Timed out waiting for bus\n");
return 1;
}
i2c_flush_rxfifo();
return 0;
}
/*
* i2c_read - Read from i2c memory
* @chip: target i2c address
* @addr: address to read from
* @alen:
* @buffer: buffer for read data
* @len: no of bytes to be read
*
* Read from i2c memory.
*/
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
unsigned long start_time_rx;
#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.
*/
chip |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8));
debug("%s: fix addr_overflow: chip %02x addr %02x\n", __func__, chip,
addr);
#endif
if (i2c_xfer_init(chip, addr, alen))
return 1;
start_time_rx = get_timer(0);
while (len) {
if (len == 1)
writel(IC_CMD | IC_STOP, &i2c_regs_p->ic_cmd_data);
else
writel(IC_CMD, &i2c_regs_p->ic_cmd_data);
if (readl(&i2c_regs_p->ic_status) & IC_STATUS_RFNE) {
*buffer++ = (uchar)readl(&i2c_regs_p->ic_cmd_data);
len--;
start_time_rx = get_timer(0);
} else if (get_timer(start_time_rx) > I2C_BYTE_TO) {
return 1;
}
}
return i2c_xfer_finish();
}
/*
* i2c_write - Write to i2c memory
* @chip: target i2c address
* @addr: address to read from
* @alen:
* @buffer: buffer for read data
* @len: no of bytes to be read
*
* Write to i2c memory.
*/
int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
int nb = len;
unsigned long start_time_tx;
#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.
*/
chip |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
addr &= ~(CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW << (alen * 8));
debug("%s: fix addr_overflow: chip %02x addr %02x\n", __func__, chip,
addr);
#endif
if (i2c_xfer_init(chip, addr, alen))
return 1;
start_time_tx = get_timer(0);
while (len) {
if (readl(&i2c_regs_p->ic_status) & IC_STATUS_TFNF) {
if (--len == 0)
writel(*buffer | IC_STOP, &i2c_regs_p->ic_cmd_data);
else
writel(*buffer, &i2c_regs_p->ic_cmd_data);
buffer++;
start_time_tx = get_timer(0);
} else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) {
printf("Timed out. i2c write Failed\n");
return 1;
}
}
return i2c_xfer_finish();
}
/*
* i2c_probe - Probe the i2c chip
*/
int i2c_probe(uchar chip)
{
u32 tmp;
int ret;
/*
* Try to read the first location of the chip.
*/
ret = i2c_read(chip, 0, 1, (uchar *)&tmp, 1);
if (ret)
i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
return ret;
}
#ifdef CONFIG_I2C_MULTI_BUS
int i2c_set_bus_num(unsigned int bus)
{
switch (bus) {
case 0:
i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE;
break;
#ifdef CONFIG_SYS_I2C_BASE1
case 1:
i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE1;
break;
#endif
#ifdef CONFIG_SYS_I2C_BASE2
case 2:
i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE2;
break;
#endif
#ifdef CONFIG_SYS_I2C_BASE3
case 3:
i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE3;
break;
#endif
#ifdef CONFIG_SYS_I2C_BASE4
case 4:
i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE4;
break;
#endif
#ifdef CONFIG_SYS_I2C_BASE5
case 5:
i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE5;
break;
#endif
#ifdef CONFIG_SYS_I2C_BASE6
case 6:
i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE6;
break;
#endif
#ifdef CONFIG_SYS_I2C_BASE7
case 7:
i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE7;
break;
#endif
#ifdef CONFIG_SYS_I2C_BASE8
case 8:
i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE8;
break;
#endif
#ifdef CONFIG_SYS_I2C_BASE9
case 9:
i2c_regs_p = (void *)CONFIG_SYS_I2C_BASE9;
break;
#endif
default:
printf("Bad bus: %d\n", bus);
return -1;
}
current_bus = bus;
if (!bus_initialized[current_bus])
i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
return 0;
}
unsigned int i2c_get_bus_num(void)
{
return current_bus;
}
#endif