u-boot/drivers/i2c/i2c-uclass.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

632 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2014 Google, Inc
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <i2c.h>
#include <malloc.h>
#include <dm/device-internal.h>
#include <dm/lists.h>
#include <dm/pinctrl.h>
#ifdef CONFIG_DM_GPIO
#include <asm/gpio.h>
#endif
#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;
msg->addr = chip->chip_addr;
msg->flags = chip->flags & DM_I2C_CHIP_10BIT ? I2C_M_TEN : 0;
msg->len = chip->offset_len;
msg->buf = offset_buf;
if (!chip->offset_len)
return -EADDRNOTAVAIL;
assert(chip->offset_len <= I2C_MAX_OFFSET_LEN);
offset_len = chip->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 = chip->chip_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 = chip->chip_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) {
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;
}
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;
}
#ifdef CONFIG_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);
}
static int i2c_deblock_gpio_loop(struct gpio_desc *sda_pin,
struct gpio_desc *scl_pin)
{
int counter = 9;
int ret = 0;
i2c_gpio_set_pin(sda_pin, 1);
i2c_gpio_set_pin(scl_pin, 1);
udelay(5);
/* Toggle SCL until slave release SDA */
while (counter-- >= 0) {
i2c_gpio_set_pin(scl_pin, 1);
udelay(5);
i2c_gpio_set_pin(scl_pin, 0);
udelay(5);
if (i2c_gpio_get_pin(sda_pin))
break;
}
/* Then, send I2C stop */
i2c_gpio_set_pin(sda_pin, 0);
udelay(5);
i2c_gpio_set_pin(scl_pin, 1);
udelay(5);
i2c_gpio_set_pin(sda_pin, 1);
udelay(5);
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]);
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 // CONFIG_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)
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_post_probe(struct udevice *dev)
{
#if CONFIG_IS_ENABLED(OF_CONTROL)
struct dm_i2c_bus *i2c = dev_get_uclass_priv(dev);
i2c->speed_hz = dev_read_u32_default(dev, "clock-frequency", 100000);
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)
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
}
UCLASS_DRIVER(i2c) = {
.id = UCLASS_I2C,
.name = "i2c",
.flags = DM_UC_FLAG_SEQ_ALIAS,
#if CONFIG_IS_ENABLED(OF_CONTROL)
.post_bind = dm_scan_fdt_dev,
#endif
.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,
};