u-boot/drivers/i2c/i2c-cortina.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2020
* Arthur Li, Cortina Access, arthur.li@cortina-access.com.
*/
#include <common.h>
#include <i2c.h>
#include <log.h>
#include <asm/io.h>
#include <dm.h>
#include <mapmem.h>
#include "i2c-cortina.h"
static void set_speed(struct i2c_regs *regs, int i2c_spd)
{
union ca_biw_cfg i2c_cfg;
i2c_cfg.wrd = readl(&regs->i2c_cfg);
i2c_cfg.bf.core_en = 0;
writel(i2c_cfg.wrd, &regs->i2c_cfg);
switch (i2c_spd) {
case IC_SPEED_MODE_FAST_PLUS:
i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
(5 * I2C_SPEED_FAST_PLUS_RATE) - 1;
break;
case IC_SPEED_MODE_STANDARD:
i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
(5 * I2C_SPEED_STANDARD_RATE) - 1;
break;
case IC_SPEED_MODE_FAST:
default:
i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
(5 * I2C_SPEED_FAST_RATE) - 1;
break;
}
i2c_cfg.bf.core_en = 1;
writel(i2c_cfg.wrd, &regs->i2c_cfg);
}
static int ca_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
{
struct ca_i2c *priv = dev_get_priv(bus);
int i2c_spd;
if (speed >= I2C_SPEED_FAST_PLUS_RATE) {
i2c_spd = IC_SPEED_MODE_FAST_PLUS;
priv->speed = I2C_SPEED_FAST_PLUS_RATE;
} else if (speed >= I2C_SPEED_FAST_RATE) {
i2c_spd = IC_SPEED_MODE_FAST;
priv->speed = I2C_SPEED_FAST_RATE;
} else {
i2c_spd = IC_SPEED_MODE_STANDARD;
priv->speed = I2C_SPEED_STANDARD_RATE;
}
set_speed(priv->regs, i2c_spd);
return 0;
}
static int ca_i2c_get_bus_speed(struct udevice *bus)
{
struct ca_i2c *priv = dev_get_priv(bus);
return priv->speed;
}
static void ca_i2c_init(struct i2c_regs *regs)
{
union ca_biw_cfg i2c_cfg;
i2c_cfg.wrd = readl(&regs->i2c_cfg);
i2c_cfg.bf.core_en = 0;
i2c_cfg.bf.biw_soft_reset = 1;
writel(i2c_cfg.wrd, &regs->i2c_cfg);
mdelay(10);
i2c_cfg.bf.biw_soft_reset = 0;
writel(i2c_cfg.wrd, &regs->i2c_cfg);
set_speed(regs, IC_SPEED_MODE_STANDARD);
i2c_cfg.wrd = readl(&regs->i2c_cfg);
i2c_cfg.bf.core_en = 1;
writel(i2c_cfg.wrd, &regs->i2c_cfg);
}
static int i2c_wait_complete(struct i2c_regs *regs)
{
union ca_biw_ctrl i2c_ctrl;
unsigned long start_time_bb = get_timer(0);
i2c_ctrl.wrd = readl(&regs->i2c_ctrl);
while (i2c_ctrl.bf.biwdone == 0) {
i2c_ctrl.wrd = readl(&regs->i2c_ctrl);
if (get_timer(start_time_bb) >
(unsigned long)(I2C_BYTE_TO_BB)) {
printf("%s not done!!!\n", __func__);
return -ETIMEDOUT;
}
}
/* Clear done bit */
writel(i2c_ctrl.wrd, &regs->i2c_ctrl);
return 0;
}
static void i2c_setaddress(struct i2c_regs *regs, unsigned int i2c_addr,
int write_read)
{
writel(i2c_addr | write_read, &regs->i2c_txr);
writel(BIW_CTRL_START | BIW_CTRL_WRITE,
&regs->i2c_ctrl);
i2c_wait_complete(regs);
}
static int i2c_wait_for_bus_busy(struct i2c_regs *regs)
{
union ca_biw_ack i2c_ack;
unsigned long start_time_bb = get_timer(0);
i2c_ack.wrd = readl(&regs->i2c_ack);
while (i2c_ack.bf.biw_busy) {
i2c_ack.wrd = readl(&regs->i2c_ack);
if (get_timer(start_time_bb) >
(unsigned long)(I2C_BYTE_TO_BB)) {
printf("%s: timeout!\n", __func__);
return -ETIMEDOUT;
}
}
return 0;
}
static int i2c_xfer_init(struct i2c_regs *regs, uint8_t chip, uint addr,
int alen, int write_read)
{
int addr_len = alen;
if (i2c_wait_for_bus_busy(regs))
return 1;
/* First cycle must write addr + offset */
chip = ((chip & 0x7F) << 1);
if (alen == 0 && write_read == I2C_CMD_RD)
i2c_setaddress(regs, chip, I2C_CMD_RD);
else
i2c_setaddress(regs, chip, I2C_CMD_WT);
while (alen) {
alen--;
writel(addr, &regs->i2c_txr);
if (write_read == I2C_CMD_RD)
writel(BIW_CTRL_WRITE | BIW_CTRL_STOP,
&regs->i2c_ctrl);
else
writel(BIW_CTRL_WRITE, &regs->i2c_ctrl);
i2c_wait_complete(regs);
}
/* Send address again with Read flag if it's read command */
if (write_read == I2C_CMD_RD && addr_len > 0)
i2c_setaddress(regs, chip, I2C_CMD_RD);
return 0;
}
static int i2c_xfer_finish(struct i2c_regs *regs)
{
/* Dummy read makes bus free */
writel(BIW_CTRL_READ | BIW_CTRL_STOP, &regs->i2c_ctrl);
i2c_wait_complete(regs);
if (i2c_wait_for_bus_busy(regs)) {
printf("Timed out waiting for bus\n");
return -ETIMEDOUT;
}
return 0;
}
static int ca_i2c_read(struct i2c_regs *regs, uint8_t chip, uint addr,
int alen, uint8_t *buffer, int len)
{
unsigned long start_time_rx;
int rc = 0;
rc = i2c_xfer_init(regs, chip, addr, alen, I2C_CMD_RD);
if (rc)
return rc;
start_time_rx = get_timer(0);
while (len) {
/* ACK_IN is ack value to send during read.
* ack high only on the very last byte!
*/
if (len == 1)
writel(BIW_CTRL_READ | BIW_CTRL_ACK_IN | BIW_CTRL_STOP,
&regs->i2c_ctrl);
else
writel(BIW_CTRL_READ, &regs->i2c_ctrl);
rc = i2c_wait_complete(regs);
udelay(1);
if (rc == 0) {
*buffer++ =
(uchar) readl(&regs->i2c_rxr);
len--;
start_time_rx = get_timer(0);
} else if (get_timer(start_time_rx) > I2C_BYTE_TO) {
return -ETIMEDOUT;
}
}
i2c_xfer_finish(regs);
return rc;
}
static int ca_i2c_write(struct i2c_regs *regs, uint8_t chip, uint addr,
int alen, uint8_t *buffer, int len)
{
int rc, nb = len;
unsigned long start_time_tx;
rc = i2c_xfer_init(regs, chip, addr, alen, I2C_CMD_WT);
if (rc)
return rc;
start_time_tx = get_timer(0);
while (len) {
writel(*buffer, &regs->i2c_txr);
if (len == 1)
writel(BIW_CTRL_WRITE | BIW_CTRL_STOP,
&regs->i2c_ctrl);
else
writel(BIW_CTRL_WRITE, &regs->i2c_ctrl);
rc = i2c_wait_complete(regs);
if (rc == 0) {
len--;
buffer++;
start_time_tx = get_timer(0);
} else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) {
return -ETIMEDOUT;
}
}
return 0;
}
static int ca_i2c_probe_chip(struct udevice *bus, uint chip_addr,
uint chip_flags)
{
struct ca_i2c *priv = dev_get_priv(bus);
int ret;
u32 tmp;
/* Try to read the first location of the chip */
ret = ca_i2c_read(priv->regs, chip_addr, 0, 1, (uchar *)&tmp, 1);
if (ret)
ca_i2c_init(priv->regs);
return ret;
}
static int ca_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
{
struct ca_i2c *priv = dev_get_priv(bus);
int ret;
debug("i2c_xfer: %d messages\n", nmsgs);
for (; nmsgs > 0; nmsgs--, msg++) {
debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
if (msg->flags & I2C_M_RD)
ret = ca_i2c_read(priv->regs, msg->addr, 0, 0,
msg->buf, msg->len);
else
ret = ca_i2c_write(priv->regs, msg->addr, 0, 0,
msg->buf, msg->len);
if (ret) {
printf("i2c_xfer: %s error\n",
msg->flags & I2C_M_RD ? "read" : "write");
return ret;
}
}
return 0;
}
static const struct dm_i2c_ops ca_i2c_ops = {
.xfer = ca_i2c_xfer,
.probe_chip = ca_i2c_probe_chip,
.set_bus_speed = ca_i2c_set_bus_speed,
.get_bus_speed = ca_i2c_get_bus_speed,
};
static const struct udevice_id ca_i2c_ids[] = {
{ .compatible = "cortina,ca-i2c", },
{ }
};
static int ca_i2c_probe(struct udevice *bus)
{
struct ca_i2c *priv = dev_get_priv(bus);
ca_i2c_init(priv->regs);
return 0;
}
static int ca_i2c_of_to_plat(struct udevice *bus)
{
struct ca_i2c *priv = dev_get_priv(bus);
priv->regs = map_sysmem(dev_read_addr(bus), sizeof(struct i2c_regs));
if (!priv->regs) {
printf("I2C: base address is invalid\n");
return -EINVAL;
}
return 0;
}
U_BOOT_DRIVER(i2c_cortina) = {
.name = "i2c_cortina",
.id = UCLASS_I2C,
.of_match = ca_i2c_ids,
.of_to_plat = ca_i2c_of_to_plat,
.probe = ca_i2c_probe,
.priv_auto = sizeof(struct ca_i2c),
.ops = &ca_i2c_ops,
.flags = DM_FLAG_PRE_RELOC,
};