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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2013
* Dirk Eibach, Guntermann & Drunck GmbH, dirk.eibach@gdsys.cc
*/
#include <common.h>
#include <i2c.h>
#include <dm.h>
#include <regmap.h>
#include <log.h>
#include <asm/global_data.h>
#include <asm/unaligned.h>
#include <linux/bitops.h>
#include <linux/delay.h>
struct ihs_i2c_priv {
uint speed;
struct regmap *map;
};
struct ihs_i2c_regs {
u16 interrupt_status;
u16 interrupt_enable_control;
u16 write_mailbox_ext;
u16 write_mailbox;
u16 read_mailbox_ext;
u16 read_mailbox;
};
#define ihs_i2c_set(map, member, val) \
regmap_set(map, struct ihs_i2c_regs, member, val)
#define ihs_i2c_get(map, member, valp) \
regmap_get(map, struct ihs_i2c_regs, member, valp)
enum {
I2CINT_ERROR_EV = BIT(13),
I2CINT_TRANSMIT_EV = BIT(14),
I2CINT_RECEIVE_EV = BIT(15),
};
enum {
I2CMB_READ = 0 << 10,
I2CMB_WRITE = 1 << 10,
I2CMB_1BYTE = 0 << 11,
I2CMB_2BYTE = 1 << 11,
I2CMB_DONT_HOLD_BUS = 0 << 13,
I2CMB_HOLD_BUS = 1 << 13,
I2CMB_NATIVE = 2 << 14,
};
enum {
I2COP_WRITE = 0,
I2COP_READ = 1,
};
static int wait_for_int(struct udevice *dev, int read)
{
u16 val;
uint ctr = 0;
struct ihs_i2c_priv *priv = dev_get_priv(dev);
ihs_i2c_get(priv->map, interrupt_status, &val);
/* Wait until error or receive/transmit interrupt was raised */
while (!(val & (I2CINT_ERROR_EV
| (read ? I2CINT_RECEIVE_EV : I2CINT_TRANSMIT_EV)))) {
udelay(10);
if (ctr++ > 5000) {
debug("%s: timed out\n", __func__);
return -ETIMEDOUT;
}
ihs_i2c_get(priv->map, interrupt_status, &val);
}
return (val & I2CINT_ERROR_EV) ? -EIO : 0;
}
static int ihs_i2c_transfer(struct udevice *dev, uchar chip,
uchar *buffer, int len, int read, bool is_last)
{
u16 val;
u16 data;
int res;
struct ihs_i2c_priv *priv = dev_get_priv(dev);
/* Clear interrupt status */
data = I2CINT_ERROR_EV | I2CINT_RECEIVE_EV | I2CINT_TRANSMIT_EV;
ihs_i2c_set(priv->map, interrupt_status, data);
ihs_i2c_get(priv->map, interrupt_status, &val);
/* If we want to write and have data, write the bytes to the mailbox */
if (!read && len) {
val = buffer[0];
if (len > 1)
val |= buffer[1] << 8;
ihs_i2c_set(priv->map, write_mailbox_ext, val);
}
data = I2CMB_NATIVE
| (read ? 0 : I2CMB_WRITE)
| (chip << 1)
| ((len > 1) ? I2CMB_2BYTE : 0)
| (is_last ? 0 : I2CMB_HOLD_BUS);
ihs_i2c_set(priv->map, write_mailbox, data);
res = wait_for_int(dev, read);
if (res) {
if (res == -ETIMEDOUT)
debug("%s: time out while waiting for event\n", __func__);
return res;
}
/* If we want to read, get the bytes from the mailbox */
if (read) {
ihs_i2c_get(priv->map, read_mailbox_ext, &val);
buffer[0] = val & 0xff;
if (len > 1)
buffer[1] = val >> 8;
}
return 0;
}
static int ihs_i2c_send_buffer(struct udevice *dev, uchar chip, u8 *data, int len, bool hold_bus, int read)
{
int res;
while (len) {
int transfer = min(len, 2);
bool is_last = len <= transfer;
res = ihs_i2c_transfer(dev, chip, data, transfer, read,
hold_bus ? false : is_last);
if (res)
return res;
data += transfer;
len -= transfer;
}
return 0;
}
static int ihs_i2c_address(struct udevice *dev, uchar chip, u8 *addr, int alen,
bool hold_bus)
{
return ihs_i2c_send_buffer(dev, chip, addr, alen, hold_bus, I2COP_WRITE);
}
static int ihs_i2c_access(struct udevice *dev, uchar chip, u8 *addr,
int alen, uchar *buffer, int len, int read)
{
int res;
/* Don't hold the bus if length of data to send/receive is zero */
if (len <= 0)
return -EINVAL;
res = ihs_i2c_address(dev, chip, addr, alen, len);
if (res)
return res;
return ihs_i2c_send_buffer(dev, chip, buffer, len, false, read);
}
int ihs_i2c_probe(struct udevice *bus)
{
struct ihs_i2c_priv *priv = dev_get_priv(bus);
regmap_init_mem(dev_ofnode(bus), &priv->map);
return 0;
}
static int ihs_i2c_set_bus_speed(struct udevice *bus, uint speed)
{
struct ihs_i2c_priv *priv = dev_get_priv(bus);
if (speed != priv->speed && priv->speed != 0)
return -EINVAL;
priv->speed = speed;
return 0;
}
static int ihs_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
{
struct i2c_msg *dmsg, *omsg, dummy;
memset(&dummy, 0, sizeof(struct i2c_msg));
/* We expect either two messages (one with an offset and one with the
* actual data) or one message (just data)
*/
if (nmsgs > 2 || nmsgs == 0) {
debug("%s: Only one or two messages are supported\n", __func__);
return -ENOTSUPP;
}
omsg = nmsgs == 1 ? &dummy : msg;
dmsg = nmsgs == 1 ? msg : msg + 1;
if (dmsg->flags & I2C_M_RD)
return ihs_i2c_access(bus, dmsg->addr, omsg->buf,
omsg->len, dmsg->buf, dmsg->len,
I2COP_READ);
else
return ihs_i2c_access(bus, dmsg->addr, omsg->buf,
omsg->len, dmsg->buf, dmsg->len,
I2COP_WRITE);
}
static int ihs_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
u32 chip_flags)
{
uchar buffer[2];
int res;
res = ihs_i2c_transfer(bus, chip_addr, buffer, 0, I2COP_READ, true);
if (res)
return res;
return 0;
}
static const struct dm_i2c_ops ihs_i2c_ops = {
.xfer = ihs_i2c_xfer,
.probe_chip = ihs_i2c_probe_chip,
.set_bus_speed = ihs_i2c_set_bus_speed,
};
static const struct udevice_id ihs_i2c_ids[] = {
{ .compatible = "gdsys,ihs_i2cmaster", },
{ /* sentinel */ }
};
U_BOOT_DRIVER(i2c_ihs) = {
.name = "i2c_ihs",
.id = UCLASS_I2C,
.of_match = ihs_i2c_ids,
.probe = ihs_i2c_probe,
.priv_auto = sizeof(struct ihs_i2c_priv),
.ops = &ihs_i2c_ops,
};
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