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

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2014 Google, Inc
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <i2c.h>
#include <log.h>
#include <malloc.h>
#include <dm/device-internal.h>
#include <dm/lists.h>
#include <dm/pinctrl.h>
#if CONFIG_IS_ENABLED(DM_GPIO)
#include <asm/gpio.h>
#endif
#include <linux/delay.h>
#define I2C_MAX_OFFSET_LEN 4
enum {
PIN_SDA = 0,
PIN_SCL,
PIN_COUNT,
};
/* Useful debugging function */
void i2c_dump_msgs(struct i2c_msg *msg, int nmsgs)
{
int i;
for (i = 0; i < nmsgs; i++) {
struct i2c_msg *m = &msg[i];
printf(" %s %x len=%x", m->flags & I2C_M_RD ? "R" : "W",
msg->addr, msg->len);
if (!(m->flags & I2C_M_RD))
printf(": %x", m->buf[0]);
printf("\n");
}
}
/**
* i2c_setup_offset() - Set up a new message with a chip offset
*
* @chip: Chip to use
* @offset: Byte offset within chip
* @offset_buf: Place to put byte offset
* @msg: Message buffer
* @return 0 if OK, -EADDRNOTAVAIL if the offset length is 0. In that case the
* message is still set up but will not contain an offset.
*/
static int i2c_setup_offset(struct dm_i2c_chip *chip, uint offset,
uint8_t offset_buf[], struct i2c_msg *msg)
{
int offset_len = chip->offset_len;
msg->addr = chip->chip_addr;
if (chip->chip_addr_offset_mask)
msg->addr |= (offset >> (8 * offset_len)) &
chip->chip_addr_offset_mask;
msg->flags = chip->flags & DM_I2C_CHIP_10BIT ? I2C_M_TEN : 0;
msg->len = chip->offset_len;
msg->buf = offset_buf;
if (!offset_len)
return -EADDRNOTAVAIL;
assert(offset_len <= I2C_MAX_OFFSET_LEN);
while (offset_len--)
*offset_buf++ = offset >> (8 * offset_len);
return 0;
}
static int i2c_read_bytewise(struct udevice *dev, uint offset,
uint8_t *buffer, int len)
{
struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
struct udevice *bus = dev_get_parent(dev);
struct dm_i2c_ops *ops = i2c_get_ops(bus);
struct i2c_msg msg[2], *ptr;
uint8_t offset_buf[I2C_MAX_OFFSET_LEN];
int ret;
int i;
for (i = 0; i < len; i++) {
if (i2c_setup_offset(chip, offset + i, offset_buf, msg))
return -EINVAL;
ptr = msg + 1;
ptr->addr = msg->addr;
ptr->flags = msg->flags | I2C_M_RD;
ptr->len = 1;
ptr->buf = &buffer[i];
ptr++;
ret = ops->xfer(bus, msg, ptr - msg);
if (ret)
return ret;
}
return 0;
}
static int i2c_write_bytewise(struct udevice *dev, uint offset,
const uint8_t *buffer, int len)
{
struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
struct udevice *bus = dev_get_parent(dev);
struct dm_i2c_ops *ops = i2c_get_ops(bus);
struct i2c_msg msg[1];
uint8_t buf[I2C_MAX_OFFSET_LEN + 1];
int ret;
int i;
for (i = 0; i < len; i++) {
if (i2c_setup_offset(chip, offset + i, buf, msg))
return -EINVAL;
buf[msg->len++] = buffer[i];
ret = ops->xfer(bus, msg, 1);
if (ret)
return ret;
}
return 0;
}
int dm_i2c_read(struct udevice *dev, uint offset, uint8_t *buffer, int len)
{
struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
struct udevice *bus = dev_get_parent(dev);
struct dm_i2c_ops *ops = i2c_get_ops(bus);
struct i2c_msg msg[2], *ptr;
uint8_t offset_buf[I2C_MAX_OFFSET_LEN];
int msg_count;
if (!ops->xfer)
return -ENOSYS;
if (chip->flags & DM_I2C_CHIP_RD_ADDRESS)
return i2c_read_bytewise(dev, offset, buffer, len);
ptr = msg;
if (!i2c_setup_offset(chip, offset, offset_buf, ptr))
ptr++;
if (len) {
ptr->addr = msg->addr;
ptr->flags = chip->flags & DM_I2C_CHIP_10BIT ? I2C_M_TEN : 0;
ptr->flags |= I2C_M_RD;
ptr->len = len;
ptr->buf = buffer;
ptr++;
}
msg_count = ptr - msg;
return ops->xfer(bus, msg, msg_count);
}
int dm_i2c_write(struct udevice *dev, uint offset, const uint8_t *buffer,
int len)
{
struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
struct udevice *bus = dev_get_parent(dev);
struct dm_i2c_ops *ops = i2c_get_ops(bus);
struct i2c_msg msg[1];
if (!ops->xfer)
return -ENOSYS;
if (chip->flags & DM_I2C_CHIP_WR_ADDRESS)
return i2c_write_bytewise(dev, offset, buffer, len);
/*
* The simple approach would be to send two messages here: one to
* set the offset and one to write the bytes. However some drivers
* will not be expecting this, and some chips won't like how the
* driver presents this on the I2C bus.
*
* The API does not support separate offset and data. We could extend
* it with a flag indicating that there is data in the next message
* that needs to be processed in the same transaction. We could
* instead add an additional buffer to each message. For now, handle
* this in the uclass since it isn't clear what the impact on drivers
* would be with this extra complication. Unfortunately this means
* copying the message.
*
* Use the stack for small messages, malloc() for larger ones. We
* need to allow space for the offset (up to 4 bytes) and the message
* itself.
*/
if (len < 64) {
uint8_t buf[I2C_MAX_OFFSET_LEN + len];
i2c_setup_offset(chip, offset, buf, msg);
msg->len += len;
memcpy(buf + chip->offset_len, buffer, len);
return ops->xfer(bus, msg, 1);
} else {
uint8_t *buf;
int ret;
buf = malloc(I2C_MAX_OFFSET_LEN + len);
if (!buf)
return -ENOMEM;
i2c_setup_offset(chip, offset, buf, msg);
msg->len += len;
memcpy(buf + chip->offset_len, buffer, len);
ret = ops->xfer(bus, msg, 1);
free(buf);
return ret;
}
}
int dm_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs)
{
struct udevice *bus = dev_get_parent(dev);
struct dm_i2c_ops *ops = i2c_get_ops(bus);
if (!ops->xfer)
return -ENOSYS;
return ops->xfer(bus, msg, nmsgs);
}
int dm_i2c_reg_read(struct udevice *dev, uint offset)
{
uint8_t val;
int ret;
ret = dm_i2c_read(dev, offset, &val, 1);
if (ret < 0)
return ret;
return val;
}
int dm_i2c_reg_write(struct udevice *dev, uint offset, uint value)
{
uint8_t val = value;
return dm_i2c_write(dev, offset, &val, 1);
}
/**
* i2c_probe_chip() - probe for a chip on a bus
*
* @bus: Bus to probe
* @chip_addr: Chip address to probe
* @flags: Flags for the chip
* @return 0 if found, -ENOSYS if the driver is invalid, -EREMOTEIO if the chip
* does not respond to probe
*/
static int i2c_probe_chip(struct udevice *bus, uint chip_addr,
enum dm_i2c_chip_flags chip_flags)
{
struct dm_i2c_ops *ops = i2c_get_ops(bus);
struct i2c_msg msg[1];
int ret;
if (ops->probe_chip) {
ret = ops->probe_chip(bus, chip_addr, chip_flags);
if (!ret || ret != -ENOSYS)
return ret;
}
if (!ops->xfer)
return -ENOSYS;
/* Probe with a zero-length message */
msg->addr = chip_addr;
msg->flags = chip_flags & DM_I2C_CHIP_10BIT ? I2C_M_TEN : 0;
msg->len = 0;
msg->buf = NULL;
return ops->xfer(bus, msg, 1);
}
static int i2c_bind_driver(struct udevice *bus, uint chip_addr, uint offset_len,
struct udevice **devp)
{
struct dm_i2c_chip *chip;
char name[30], *str;
struct udevice *dev;
int ret;
snprintf(name, sizeof(name), "generic_%x", chip_addr);
str = strdup(name);
if (!str)
return -ENOMEM;
ret = device_bind_driver(bus, "i2c_generic_chip_drv", str, &dev);
debug("%s: device_bind_driver: ret=%d\n", __func__, ret);
if (ret)
goto err_bind;
/* Tell the device what we know about it */
chip = dev_get_parent_platdata(dev);
chip->chip_addr = chip_addr;
chip->offset_len = offset_len;
ret = device_probe(dev);
debug("%s: device_probe: ret=%d\n", __func__, ret);
if (ret)
goto err_probe;
*devp = dev;
return 0;
err_probe:
/*
* If the device failed to probe, unbind it. There is nothing there
* on the bus so we don't want to leave it lying around
*/
device_unbind(dev);
err_bind:
free(str);
return ret;
}
int i2c_get_chip(struct udevice *bus, uint chip_addr, uint offset_len,
struct udevice **devp)
{
struct udevice *dev;
debug("%s: Searching bus '%s' for address %02x: ", __func__,
bus->name, chip_addr);
for (device_find_first_child(bus, &dev); dev;
device_find_next_child(&dev)) {
struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
int ret;
if (chip->chip_addr == (chip_addr &
~chip->chip_addr_offset_mask)) {
ret = device_probe(dev);
debug("found, ret=%d\n", ret);
if (ret)
return ret;
*devp = dev;
return 0;
}
}
debug("not found\n");
return i2c_bind_driver(bus, chip_addr, offset_len, devp);
}
int i2c_get_chip_for_busnum(int busnum, int chip_addr, uint offset_len,
struct udevice **devp)
{
struct udevice *bus;
int ret;
ret = uclass_get_device_by_seq(UCLASS_I2C, busnum, &bus);
if (ret) {
debug("Cannot find I2C bus %d\n", busnum);
return ret;
}
/* detect the presence of the chip on the bus */
ret = i2c_probe_chip(bus, chip_addr, 0);
debug("%s: bus='%s', address %02x, ret=%d\n", __func__, bus->name,
chip_addr, ret);
if (ret) {
debug("Cannot detect I2C chip %02x on bus %d\n", chip_addr,
busnum);
return ret;
}
ret = i2c_get_chip(bus, chip_addr, offset_len, devp);
if (ret) {
debug("Cannot find I2C chip %02x on bus %d\n", chip_addr,
busnum);
return ret;
}
return 0;
}
int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
struct udevice **devp)
{
int ret;
*devp = NULL;
/* First probe that chip */
ret = i2c_probe_chip(bus, chip_addr, chip_flags);
debug("%s: bus='%s', address %02x, ret=%d\n", __func__, bus->name,
chip_addr, ret);
if (ret)
return ret;
/* The chip was found, see if we have a driver, and probe it */
ret = i2c_get_chip(bus, chip_addr, 1, devp);
debug("%s: i2c_get_chip: ret=%d\n", __func__, ret);
return ret;
}
int dm_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
{
struct dm_i2c_ops *ops = i2c_get_ops(bus);
struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus);
int ret;
/*
* If we have a method, call it. If not then the driver probably wants
* to deal with speed changes on the next transfer. It can easily read
* the current speed from this uclass
*/
if (ops->set_bus_speed) {
ret = ops->set_bus_speed(bus, speed);
if (ret)
return ret;
}
i2c->speed_hz = speed;
return 0;
}
int dm_i2c_get_bus_speed(struct udevice *bus)
{
struct dm_i2c_ops *ops = i2c_get_ops(bus);
struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus);
if (!ops->get_bus_speed)
return i2c->speed_hz;
return ops->get_bus_speed(bus);
}
int i2c_set_chip_flags(struct udevice *dev, uint flags)
{
struct udevice *bus = dev->parent;
struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
struct dm_i2c_ops *ops = i2c_get_ops(bus);
int ret;
if (ops->set_flags) {
ret = ops->set_flags(dev, flags);
if (ret)
return ret;
}
chip->flags = flags;
return 0;
}
int i2c_get_chip_flags(struct udevice *dev, uint *flagsp)
{
struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
*flagsp = chip->flags;
return 0;
}
int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len)
{
struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
if (offset_len > I2C_MAX_OFFSET_LEN)
return -EINVAL;
chip->offset_len = offset_len;
return 0;
}
int i2c_get_chip_offset_len(struct udevice *dev)
{
struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
return chip->offset_len;
}
int i2c_set_chip_addr_offset_mask(struct udevice *dev, uint mask)
{
struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
chip->chip_addr_offset_mask = mask;
return 0;
}
uint i2c_get_chip_addr_offset_mask(struct udevice *dev)
{
struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
return chip->chip_addr_offset_mask;
}
#if CONFIG_IS_ENABLED(DM_GPIO)
static void i2c_gpio_set_pin(struct gpio_desc *pin, int bit)
{
if (bit)
dm_gpio_set_dir_flags(pin, GPIOD_IS_IN);
else
dm_gpio_set_dir_flags(pin, GPIOD_IS_OUT |
GPIOD_ACTIVE_LOW |
GPIOD_IS_OUT_ACTIVE);
}
static int i2c_gpio_get_pin(struct gpio_desc *pin)
{
return dm_gpio_get_value(pin);
}
int i2c_deblock_gpio_loop(struct gpio_desc *sda_pin,
struct gpio_desc *scl_pin,
unsigned int scl_count,
unsigned int start_count,
unsigned int delay)
{
int i, ret = -EREMOTEIO;
i2c_gpio_set_pin(sda_pin, 1);
i2c_gpio_set_pin(scl_pin, 1);
udelay(delay);
/* Toggle SCL until slave release SDA */
for (; scl_count; --scl_count) {
i2c_gpio_set_pin(scl_pin, 1);
udelay(delay);
i2c_gpio_set_pin(scl_pin, 0);
udelay(delay);
if (i2c_gpio_get_pin(sda_pin)) {
ret = 0;
break;
}
}
if (!ret && start_count) {
for (i = 0; i < start_count; i++) {
/* Send start condition */
udelay(delay);
i2c_gpio_set_pin(sda_pin, 1);
udelay(delay);
i2c_gpio_set_pin(scl_pin, 1);
udelay(delay);
i2c_gpio_set_pin(sda_pin, 0);
udelay(delay);
i2c_gpio_set_pin(scl_pin, 0);
}
}
/* Then, send I2C stop */
i2c_gpio_set_pin(sda_pin, 0);
udelay(delay);
i2c_gpio_set_pin(scl_pin, 1);
udelay(delay);
i2c_gpio_set_pin(sda_pin, 1);
udelay(delay);
if (!i2c_gpio_get_pin(sda_pin) || !i2c_gpio_get_pin(scl_pin))
ret = -EREMOTEIO;
return ret;
}
static int i2c_deblock_gpio(struct udevice *bus)
{
struct gpio_desc gpios[PIN_COUNT];
int ret, ret0;
ret = gpio_request_list_by_name(bus, "gpios", gpios,
ARRAY_SIZE(gpios), GPIOD_IS_IN);
if (ret != ARRAY_SIZE(gpios)) {
debug("%s: I2C Node '%s' has no 'gpios' property %s\n",
__func__, dev_read_name(bus), bus->name);
if (ret >= 0) {
gpio_free_list(bus, gpios, ret);
ret = -ENOENT;
}
goto out;
}
ret = pinctrl_select_state(bus, "gpio");
if (ret) {
debug("%s: I2C Node '%s' has no 'gpio' pinctrl state. %s\n",
__func__, dev_read_name(bus), bus->name);
goto out_no_pinctrl;
}
ret0 = i2c_deblock_gpio_loop(&gpios[PIN_SDA], &gpios[PIN_SCL], 9, 0, 5);
ret = pinctrl_select_state(bus, "default");
if (ret) {
debug("%s: I2C Node '%s' has no 'default' pinctrl state. %s\n",
__func__, dev_read_name(bus), bus->name);
}
ret = !ret ? ret0 : ret;
out_no_pinctrl:
gpio_free_list(bus, gpios, ARRAY_SIZE(gpios));
out:
return ret;
}
#else
static int i2c_deblock_gpio(struct udevice *bus)
{
return -ENOSYS;
}
#endif /* DM_GPIO */
int i2c_deblock(struct udevice *bus)
{
struct dm_i2c_ops *ops = i2c_get_ops(bus);
if (!ops->deblock)
return i2c_deblock_gpio(bus);
return ops->deblock(bus);
}
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
int i2c_chip_ofdata_to_platdata(struct udevice *dev, struct dm_i2c_chip *chip)
{
int addr;
chip->offset_len = dev_read_u32_default(dev, "u-boot,i2c-offset-len",
1);
chip->flags = 0;
addr = dev_read_u32_default(dev, "reg", -1);
if (addr == -1) {
debug("%s: I2C Node '%s' has no 'reg' property %s\n", __func__,
dev_read_name(dev), dev->name);
return -EINVAL;
}
chip->chip_addr = addr;
return 0;
}
#endif
static int i2c_pre_probe(struct udevice *dev)
{
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
struct dm_i2c_bus *i2c = dev_get_uclass_priv(dev);
unsigned int max = 0;
ofnode node;
int ret;
i2c->max_transaction_bytes = 0;
dev_for_each_subnode(node, dev) {
ret = ofnode_read_u32(node,
"u-boot,i2c-transaction-bytes",
&max);
if (!ret && max > i2c->max_transaction_bytes)
i2c->max_transaction_bytes = max;
}
debug("%s: I2C bus: %s max transaction bytes: %d\n", __func__,
dev->name, i2c->max_transaction_bytes);
#endif
return 0;
}
static int i2c_post_probe(struct udevice *dev)
{
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
struct dm_i2c_bus *i2c = dev_get_uclass_priv(dev);
i2c->speed_hz = dev_read_u32_default(dev, "clock-frequency",
I2C_SPEED_STANDARD_RATE);
return dm_i2c_set_bus_speed(dev, i2c->speed_hz);
#else
return 0;
#endif
}
static int i2c_child_post_bind(struct udevice *dev)
{
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
struct dm_i2c_chip *plat = dev_get_parent_platdata(dev);
if (!dev_of_valid(dev))
return 0;
return i2c_chip_ofdata_to_platdata(dev, plat);
#else
return 0;
#endif
}
struct i2c_priv {
int max_id;
};
static int i2c_post_bind(struct udevice *dev)
{
struct uclass *class = dev->uclass;
struct i2c_priv *priv = class->priv;
int ret = 0;
/* Just for sure */
if (!priv)
return -ENOMEM;
debug("%s: %s, req_seq=%d\n", __func__, dev->name, dev->req_seq);
/* if there is no alias ID, use the first free */
if (dev->req_seq == -1)
dev->req_seq = ++priv->max_id;
debug("%s: %s, new req_seq=%d\n", __func__, dev->name, dev->req_seq);
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
ret = dm_scan_fdt_dev(dev);
#endif
return ret;
}
int i2c_uclass_init(struct uclass *class)
{
struct i2c_priv *priv = class->priv;
/* Just for sure */
if (!priv)
return -ENOMEM;
/* Get the last allocated alias. */
if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA))
priv->max_id = dev_read_alias_highest_id("i2c");
else
priv->max_id = -1;
debug("%s: highest alias id is %d\n", __func__, priv->max_id);
return 0;
}
UCLASS_DRIVER(i2c) = {
.id = UCLASS_I2C,
.name = "i2c",
.flags = DM_UC_FLAG_SEQ_ALIAS,
.post_bind = i2c_post_bind,
.init = i2c_uclass_init,
.priv_auto_alloc_size = sizeof(struct i2c_priv),
.pre_probe = i2c_pre_probe,
.post_probe = i2c_post_probe,
.per_device_auto_alloc_size = sizeof(struct dm_i2c_bus),
.per_child_platdata_auto_alloc_size = sizeof(struct dm_i2c_chip),
.child_post_bind = i2c_child_post_bind,
};
UCLASS_DRIVER(i2c_generic) = {
.id = UCLASS_I2C_GENERIC,
.name = "i2c_generic",
};
U_BOOT_DRIVER(i2c_generic_chip_drv) = {
.name = "i2c_generic_chip_drv",
.id = UCLASS_I2C_GENERIC,
};