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