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dm: i2c: Add a uclass for I2C
The uclass implements the same operations as the current I2C framework but makes some changes to make it fit driver model better: - Remove the chip address from API calls - Remove the address length from API calls - Remove concept of 'current' I2C bus - Drop all existing init functions Acked-by: Heiko Schocher <hs@denx.de> Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Signed-off-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Simon Glass
parent
59345b1f0f
commit
c6202d857e
5 changed files with 827 additions and 0 deletions
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@ -4,6 +4,7 @@
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#
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# SPDX-License-Identifier: GPL-2.0+
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#
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obj-$(CONFIG_DM_I2C) += i2c-uclass.o
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obj-$(CONFIG_SYS_I2C_ADI) += adi_i2c.o
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obj-$(CONFIG_I2C_MV) += mv_i2c.o
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466
drivers/i2c/i2c-uclass.c
Normal file
466
drivers/i2c/i2c-uclass.c
Normal file
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@ -0,0 +1,466 @@
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/*
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* Copyright (c) 2014 Google, Inc
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*
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* SPDX-License-Identifier: GPL-2.0+
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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 <fdtdec.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/root.h>
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DECLARE_GLOBAL_DATA_PTR;
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#define I2C_MAX_OFFSET_LEN 4
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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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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_parentdata(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_parentdata(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 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_parentdata(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 i2c_write(struct udevice *dev, uint offset, const uint8_t *buffer, int len)
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{
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struct dm_i2c_chip *chip = dev_get_parentdata(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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/**
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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,
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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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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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memset(&chip, '\0', sizeof(chip));
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chip.chip_addr = chip_addr;
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chip.offset_len = 1; /* we assume */
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ret = device_probe_child(dev, &chip);
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debug("%s: device_probe_child: 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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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, 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 store;
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struct dm_i2c_chip *chip = dev_get_parentdata(dev);
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int ret;
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if (!chip) {
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chip = &store;
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i2c_chip_ofdata_to_platdata(gd->fdt_blob,
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dev->of_offset, chip);
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}
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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, devp);
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}
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int i2c_get_chip_for_busnum(int busnum, int chip_addr, 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, 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 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, 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 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 = bus->uclass_priv;
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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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/*
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* i2c_get_bus_speed:
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*
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* Returns speed of selected I2C bus in Hz
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*/
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int 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 = bus->uclass_priv;
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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_parentdata(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_parentdata(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_parentdata(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_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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* We could implement a software deblocking here if we could get
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* access to the GPIOs used by I2C, and switch them to GPIO mode
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* and then back to I2C. This is somewhat beyond our powers in
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* driver model at present, so for now just fail.
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*
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* See https://patchwork.ozlabs.org/patch/399040/
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*/
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if (!ops->deblock)
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return -ENOSYS;
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return ops->deblock(bus);
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}
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int i2c_chip_ofdata_to_platdata(const void *blob, int node,
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struct dm_i2c_chip *chip)
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{
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chip->offset_len = 1; /* default */
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chip->flags = 0;
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chip->chip_addr = fdtdec_get_int(gd->fdt_blob, node, "reg", -1);
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if (chip->chip_addr == -1) {
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debug("%s: I2C Node '%s' has no 'reg' property\n", __func__,
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fdt_get_name(blob, node, NULL));
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return -EINVAL;
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}
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return 0;
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}
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static int i2c_post_probe(struct udevice *dev)
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{
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struct dm_i2c_bus *i2c = dev->uclass_priv;
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i2c->speed_hz = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
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"clock-frequency", 100000);
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return i2c_set_bus_speed(dev, i2c->speed_hz);
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}
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int i2c_post_bind(struct udevice *dev)
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{
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/* Scan the bus for devices */
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return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
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}
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UCLASS_DRIVER(i2c) = {
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.id = UCLASS_I2C,
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.name = "i2c",
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.per_device_auto_alloc_size = sizeof(struct dm_i2c_bus),
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.post_bind = i2c_post_bind,
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.post_probe = i2c_post_probe,
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};
|
||||
|
||||
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,
|
||||
};
|
||||
|
|
@ -91,4 +91,10 @@
|
|||
#undef CONFIG_IMAGE_FORMAT_LEGACY
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_DM_I2C
|
||||
# ifdef CONFIG_SYS_I2C
|
||||
# error "Cannot define CONFIG_SYS_I2C when CONFIG_DM_I2C is used"
|
||||
# endif
|
||||
#endif
|
||||
|
||||
#endif /* __CONFIG_FALLBACKS_H */
|
||||
|
|
|
|||
|
|
@ -29,6 +29,8 @@ enum uclass_id {
|
|||
UCLASS_SPI_FLASH, /* SPI flash */
|
||||
UCLASS_CROS_EC, /* Chrome OS EC */
|
||||
UCLASS_THERMAL, /* Thermal sensor */
|
||||
UCLASS_I2C, /* I2C bus */
|
||||
UCLASS_I2C_GENERIC, /* Generic I2C device */
|
||||
|
||||
UCLASS_COUNT,
|
||||
UCLASS_INVALID = -1,
|
||||
|
|
|
|||
352
include/i2c.h
352
include/i2c.h
|
|
@ -17,6 +17,355 @@
|
|||
#ifndef _I2C_H_
|
||||
#define _I2C_H_
|
||||
|
||||
/*
|
||||
* For now there are essentially two parts to this file - driver model
|
||||
* here at the top, and the older code below (with CONFIG_SYS_I2C being
|
||||
* most recent). The plan is to migrate everything to driver model.
|
||||
* The driver model structures and API are separate as they are different
|
||||
* enough as to be incompatible for compilation purposes.
|
||||
*/
|
||||
|
||||
#ifdef CONFIG_DM_I2C
|
||||
|
||||
enum dm_i2c_chip_flags {
|
||||
DM_I2C_CHIP_10BIT = 1 << 0, /* Use 10-bit addressing */
|
||||
DM_I2C_CHIP_RD_ADDRESS = 1 << 1, /* Send address for each read byte */
|
||||
DM_I2C_CHIP_WR_ADDRESS = 1 << 2, /* Send address for each write byte */
|
||||
};
|
||||
|
||||
/**
|
||||
* struct dm_i2c_chip - information about an i2c chip
|
||||
*
|
||||
* An I2C chip is a device on the I2C bus. It sits at a particular address
|
||||
* and normally supports 7-bit or 10-bit addressing.
|
||||
*
|
||||
* To obtain this structure, use dev_get_parentdata(dev) where dev is the
|
||||
* chip to examine.
|
||||
*
|
||||
* @chip_addr: Chip address on bus
|
||||
* @offset_len: Length of offset in bytes. A single byte offset can
|
||||
* represent up to 256 bytes. A value larger than 1 may be
|
||||
* needed for larger devices.
|
||||
* @flags: Flags for this chip (dm_i2c_chip_flags)
|
||||
* @emul: Emulator for this chip address (only used for emulation)
|
||||
*/
|
||||
struct dm_i2c_chip {
|
||||
uint chip_addr;
|
||||
uint offset_len;
|
||||
uint flags;
|
||||
#ifdef CONFIG_SANDBOX
|
||||
struct udevice *emul;
|
||||
#endif
|
||||
};
|
||||
|
||||
/**
|
||||
* struct dm_i2c_bus- information about an i2c bus
|
||||
*
|
||||
* An I2C bus contains 0 or more chips on it, each at its own address. The
|
||||
* bus can operate at different speeds (measured in Hz, typically 100KHz
|
||||
* or 400KHz).
|
||||
*
|
||||
* To obtain this structure, use bus->uclass_priv where bus is the I2C
|
||||
* bus udevice.
|
||||
*
|
||||
* @speed_hz: Bus speed in hertz (typically 100000)
|
||||
*/
|
||||
struct dm_i2c_bus {
|
||||
int speed_hz;
|
||||
};
|
||||
|
||||
/**
|
||||
* i2c_read() - read bytes from an I2C chip
|
||||
*
|
||||
* To obtain an I2C device (called a 'chip') given the I2C bus address you
|
||||
* can use i2c_get_chip(). To obtain a bus by bus number use
|
||||
* uclass_get_device_by_seq(UCLASS_I2C, <bus number>).
|
||||
*
|
||||
* To set the address length of a devce use i2c_set_addr_len(). It
|
||||
* defaults to 1.
|
||||
*
|
||||
* @dev: Chip to read from
|
||||
* @offset: Offset within chip to start reading
|
||||
* @buffer: Place to put data
|
||||
* @len: Number of bytes to read
|
||||
*
|
||||
* @return 0 on success, -ve on failure
|
||||
*/
|
||||
int i2c_read(struct udevice *dev, uint offset, uint8_t *buffer,
|
||||
int len);
|
||||
|
||||
/**
|
||||
* i2c_write() - write bytes to an I2C chip
|
||||
*
|
||||
* See notes for i2c_read() above.
|
||||
*
|
||||
* @dev: Chip to write to
|
||||
* @offset: Offset within chip to start writing
|
||||
* @buffer: Buffer containing data to write
|
||||
* @len: Number of bytes to write
|
||||
*
|
||||
* @return 0 on success, -ve on failure
|
||||
*/
|
||||
int i2c_write(struct udevice *dev, uint offset, const uint8_t *buffer,
|
||||
int len);
|
||||
|
||||
/**
|
||||
* i2c_probe() - probe a particular chip address
|
||||
*
|
||||
* This can be useful to check for the existence of a chip on the bus.
|
||||
* It is typically implemented by writing the chip address to the bus
|
||||
* and checking that the chip replies with an ACK.
|
||||
*
|
||||
* @bus: Bus to probe
|
||||
* @chip_addr: 7-bit address to probe (10-bit and others are not supported)
|
||||
* @chip_flags: Flags for the probe (see enum dm_i2c_chip_flags)
|
||||
* @devp: Returns the device found, or NULL if none
|
||||
* @return 0 if a chip was found at that address, -ve if not
|
||||
*/
|
||||
int i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
|
||||
struct udevice **devp);
|
||||
|
||||
/**
|
||||
* i2c_set_bus_speed() - set the speed of a bus
|
||||
*
|
||||
* @bus: Bus to adjust
|
||||
* @speed: Requested speed in Hz
|
||||
* @return 0 if OK, -EINVAL for invalid values
|
||||
*/
|
||||
int i2c_set_bus_speed(struct udevice *bus, unsigned int speed);
|
||||
|
||||
/**
|
||||
* i2c_get_bus_speed() - get the speed of a bus
|
||||
*
|
||||
* @bus: Bus to check
|
||||
* @return speed of selected I2C bus in Hz, -ve on error
|
||||
*/
|
||||
int i2c_get_bus_speed(struct udevice *bus);
|
||||
|
||||
/**
|
||||
* i2c_set_chip_flags() - set flags for a chip
|
||||
*
|
||||
* Typically addresses are 7 bits, but for 10-bit addresses you should set
|
||||
* flags to DM_I2C_CHIP_10BIT. All accesses will then use 10-bit addressing.
|
||||
*
|
||||
* @dev: Chip to adjust
|
||||
* @flags: New flags
|
||||
* @return 0 if OK, -EINVAL if value is unsupported, other -ve value on error
|
||||
*/
|
||||
int i2c_set_chip_flags(struct udevice *dev, uint flags);
|
||||
|
||||
/**
|
||||
* i2c_get_chip_flags() - get flags for a chip
|
||||
*
|
||||
* @dev: Chip to check
|
||||
* @flagsp: Place to put flags
|
||||
* @return 0 if OK, other -ve value on error
|
||||
*/
|
||||
int i2c_get_chip_flags(struct udevice *dev, uint *flagsp);
|
||||
|
||||
/**
|
||||
* i2c_set_offset_len() - set the offset length for a chip
|
||||
*
|
||||
* The offset used to access a chip may be up to 4 bytes long. Typically it
|
||||
* is only 1 byte, which is enough for chips with 256 bytes of memory or
|
||||
* registers. The default value is 1, but you can call this function to
|
||||
* change it.
|
||||
*
|
||||
* @offset_len: New offset length value (typically 1 or 2)
|
||||
*/
|
||||
|
||||
int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len);
|
||||
/**
|
||||
* i2c_deblock() - recover a bus that is in an unknown state
|
||||
*
|
||||
* See the deblock() method in 'struct dm_i2c_ops' for full information
|
||||
*
|
||||
* @bus: Bus to recover
|
||||
* @return 0 if OK, -ve on error
|
||||
*/
|
||||
int i2c_deblock(struct udevice *bus);
|
||||
|
||||
/*
|
||||
* Not all of these flags are implemented in the U-Boot API
|
||||
*/
|
||||
enum dm_i2c_msg_flags {
|
||||
I2C_M_TEN = 0x0010, /* ten-bit chip address */
|
||||
I2C_M_RD = 0x0001, /* read data, from slave to master */
|
||||
I2C_M_STOP = 0x8000, /* send stop after this message */
|
||||
I2C_M_NOSTART = 0x4000, /* no start before this message */
|
||||
I2C_M_REV_DIR_ADDR = 0x2000, /* invert polarity of R/W bit */
|
||||
I2C_M_IGNORE_NAK = 0x1000, /* continue after NAK */
|
||||
I2C_M_NO_RD_ACK = 0x0800, /* skip the Ack bit on reads */
|
||||
I2C_M_RECV_LEN = 0x0400, /* length is first received byte */
|
||||
};
|
||||
|
||||
/**
|
||||
* struct i2c_msg - an I2C message
|
||||
*
|
||||
* @addr: Slave address
|
||||
* @flags: Flags (see enum dm_i2c_msg_flags)
|
||||
* @len: Length of buffer in bytes, may be 0 for a probe
|
||||
* @buf: Buffer to send/receive, or NULL if no data
|
||||
*/
|
||||
struct i2c_msg {
|
||||
uint addr;
|
||||
uint flags;
|
||||
uint len;
|
||||
u8 *buf;
|
||||
};
|
||||
|
||||
/**
|
||||
* struct i2c_msg_list - a list of I2C messages
|
||||
*
|
||||
* This is called i2c_rdwr_ioctl_data in Linux but the name does not seem
|
||||
* appropriate in U-Boot.
|
||||
*
|
||||
* @msg: Pointer to i2c_msg array
|
||||
* @nmsgs: Number of elements in the array
|
||||
*/
|
||||
struct i2c_msg_list {
|
||||
struct i2c_msg *msgs;
|
||||
uint nmsgs;
|
||||
};
|
||||
|
||||
/**
|
||||
* struct dm_i2c_ops - driver operations for I2C uclass
|
||||
*
|
||||
* Drivers should support these operations unless otherwise noted. These
|
||||
* operations are intended to be used by uclass code, not directly from
|
||||
* other code.
|
||||
*/
|
||||
struct dm_i2c_ops {
|
||||
/**
|
||||
* xfer() - transfer a list of I2C messages
|
||||
*
|
||||
* @bus: Bus to read from
|
||||
* @msg: List of messages to transfer
|
||||
* @nmsgs: Number of messages in the list
|
||||
* @return 0 if OK, -EREMOTEIO if the slave did not ACK a byte,
|
||||
* -ECOMM if the speed cannot be supported, -EPROTO if the chip
|
||||
* flags cannot be supported, other -ve value on some other error
|
||||
*/
|
||||
int (*xfer)(struct udevice *bus, struct i2c_msg *msg, int nmsgs);
|
||||
|
||||
/**
|
||||
* probe_chip() - probe for the presense of a chip address
|
||||
*
|
||||
* This function is optional. If omitted, the uclass will send a zero
|
||||
* length message instead.
|
||||
*
|
||||
* @bus: Bus to probe
|
||||
* @chip_addr: Chip address to probe
|
||||
* @chip_flags: Probe flags (enum dm_i2c_chip_flags)
|
||||
* @return 0 if chip was found, -EREMOTEIO if not, -ENOSYS to fall back
|
||||
* to default probem other -ve value on error
|
||||
*/
|
||||
int (*probe_chip)(struct udevice *bus, uint chip_addr, uint chip_flags);
|
||||
|
||||
/**
|
||||
* set_bus_speed() - set the speed of a bus (optional)
|
||||
*
|
||||
* The bus speed value will be updated by the uclass if this function
|
||||
* does not return an error. This method is optional - if it is not
|
||||
* provided then the driver can read the speed from
|
||||
* bus->uclass_priv->speed_hz
|
||||
*
|
||||
* @bus: Bus to adjust
|
||||
* @speed: Requested speed in Hz
|
||||
* @return 0 if OK, -EINVAL for invalid values
|
||||
*/
|
||||
int (*set_bus_speed)(struct udevice *bus, unsigned int speed);
|
||||
|
||||
/**
|
||||
* get_bus_speed() - get the speed of a bus (optional)
|
||||
*
|
||||
* Normally this can be provided by the uclass, but if you want your
|
||||
* driver to check the bus speed by looking at the hardware, you can
|
||||
* implement that here. This method is optional. This method would
|
||||
* normally be expected to return bus->uclass_priv->speed_hz.
|
||||
*
|
||||
* @bus: Bus to check
|
||||
* @return speed of selected I2C bus in Hz, -ve on error
|
||||
*/
|
||||
int (*get_bus_speed)(struct udevice *bus);
|
||||
|
||||
/**
|
||||
* set_flags() - set the flags for a chip (optional)
|
||||
*
|
||||
* This is generally implemented by the uclass, but drivers can
|
||||
* check the value to ensure that unsupported options are not used.
|
||||
* This method is optional. If provided, this method will always be
|
||||
* called when the flags change.
|
||||
*
|
||||
* @dev: Chip to adjust
|
||||
* @flags: New flags value
|
||||
* @return 0 if OK, -EINVAL if value is unsupported
|
||||
*/
|
||||
int (*set_flags)(struct udevice *dev, uint flags);
|
||||
|
||||
/**
|
||||
* deblock() - recover a bus that is in an unknown state
|
||||
*
|
||||
* I2C is a synchronous protocol and resets of the processor in the
|
||||
* middle of an access can block the I2C Bus until a powerdown of
|
||||
* the full unit is done. This is because slaves can be stuck
|
||||
* waiting for addition bus transitions for a transaction that will
|
||||
* never complete. Resetting the I2C master does not help. The only
|
||||
* way is to force the bus through a series of transitions to make
|
||||
* sure that all slaves are done with the transaction. This method
|
||||
* performs this 'deblocking' if support by the driver.
|
||||
*
|
||||
* This method is optional.
|
||||
*/
|
||||
int (*deblock)(struct udevice *bus);
|
||||
};
|
||||
|
||||
#define i2c_get_ops(dev) ((struct dm_i2c_ops *)(dev)->driver->ops)
|
||||
|
||||
/**
|
||||
* i2c_get_chip() - get a device to use to access a chip on a bus
|
||||
*
|
||||
* This returns the device for the given chip address. The device can then
|
||||
* be used with calls to i2c_read(), i2c_write(), i2c_probe(), etc.
|
||||
*
|
||||
* @bus: Bus to examine
|
||||
* @chip_addr: Chip address for the new device
|
||||
* @devp: Returns pointer to new device if found or -ENODEV if not
|
||||
* found
|
||||
*/
|
||||
int i2c_get_chip(struct udevice *bus, uint chip_addr, struct udevice **devp);
|
||||
|
||||
/**
|
||||
* i2c_get_chip() - get a device to use to access a chip on a bus number
|
||||
*
|
||||
* This returns the device for the given chip address on a particular bus
|
||||
* number.
|
||||
*
|
||||
* @busnum: Bus number to examine
|
||||
* @chip_addr: Chip address for the new device
|
||||
* @devp: Returns pointer to new device if found or -ENODEV if not
|
||||
* found
|
||||
*/
|
||||
int i2c_get_chip_for_busnum(int busnum, int chip_addr, struct udevice **devp);
|
||||
|
||||
/**
|
||||
* i2c_chip_ofdata_to_platdata() - Decode standard I2C platform data
|
||||
*
|
||||
* This decodes the chip address from a device tree node and puts it into
|
||||
* its dm_i2c_chip structure. This should be called in your driver's
|
||||
* ofdata_to_platdata() method.
|
||||
*
|
||||
* @blob: Device tree blob
|
||||
* @node: Node offset to read from
|
||||
* @spi: Place to put the decoded information
|
||||
*/
|
||||
int i2c_chip_ofdata_to_platdata(const void *blob, int node,
|
||||
struct dm_i2c_chip *chip);
|
||||
|
||||
#endif
|
||||
|
||||
#ifndef CONFIG_DM_I2C
|
||||
|
||||
/*
|
||||
* WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
|
||||
*
|
||||
|
|
@ -451,4 +800,7 @@ int i2c_get_bus_num_fdt(int node);
|
|||
* @return 0 if port was reset, -1 if not found
|
||||
*/
|
||||
int i2c_reset_port_fdt(const void *blob, int node);
|
||||
|
||||
#endif /* !CONFIG_DM_I2C */
|
||||
|
||||
#endif /* _I2C_H_ */
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue