diff options
| -rw-r--r-- | drivers/i2c/i2c-uclass.c | 34 | ||||
| -rw-r--r-- | include/i2c.h | 33 |
2 files changed, 60 insertions, 7 deletions
diff --git a/drivers/i2c/i2c-uclass.c b/drivers/i2c/i2c-uclass.c index e47abf1833..44aace3a36 100644 --- a/drivers/i2c/i2c-uclass.c +++ b/drivers/i2c/i2c-uclass.c @@ -52,16 +52,19 @@ void i2c_dump_msgs(struct i2c_msg *msg, int nmsgs) static int i2c_setup_offset(struct dm_i2c_chip *chip, uint offset, uint8_t offset_buf[], struct i2c_msg *msg) { - int offset_len; + int offset_len = chip->offset_len; msg->addr = chip->chip_addr; + if (chip->chip_addr_offset_mask) + msg->addr |= (offset >> (8 * offset_len)) & + chip->chip_addr_offset_mask; msg->flags = chip->flags & DM_I2C_CHIP_10BIT ? I2C_M_TEN : 0; msg->len = chip->offset_len; msg->buf = offset_buf; - if (!chip->offset_len) + if (!offset_len) return -EADDRNOTAVAIL; - assert(chip->offset_len <= I2C_MAX_OFFSET_LEN); - offset_len = chip->offset_len; + assert(offset_len <= I2C_MAX_OFFSET_LEN); + while (offset_len--) *offset_buf++ = offset >> (8 * offset_len); @@ -83,7 +86,7 @@ static int i2c_read_bytewise(struct udevice *dev, uint offset, if (i2c_setup_offset(chip, offset + i, offset_buf, msg)) return -EINVAL; ptr = msg + 1; - ptr->addr = chip->chip_addr; + ptr->addr = msg->addr; ptr->flags = msg->flags | I2C_M_RD; ptr->len = 1; ptr->buf = &buffer[i]; @@ -139,7 +142,7 @@ int dm_i2c_read(struct udevice *dev, uint offset, uint8_t *buffer, int len) ptr++; if (len) { - ptr->addr = chip->chip_addr; + ptr->addr = msg->addr; ptr->flags = chip->flags & DM_I2C_CHIP_10BIT ? I2C_M_TEN : 0; ptr->flags |= I2C_M_RD; ptr->len = len; @@ -323,7 +326,8 @@ int i2c_get_chip(struct udevice *bus, uint chip_addr, uint offset_len, struct dm_i2c_chip *chip = dev_get_parent_platdata(dev); int ret; - if (chip->chip_addr == chip_addr) { + if (chip->chip_addr == (chip_addr & + ~chip->chip_addr_offset_mask)) { ret = device_probe(dev); debug("found, ret=%d\n", ret); if (ret) @@ -465,6 +469,22 @@ int i2c_get_chip_offset_len(struct udevice *dev) return chip->offset_len; } +int i2c_set_chip_addr_offset_mask(struct udevice *dev, uint mask) +{ + struct dm_i2c_chip *chip = dev_get_parent_platdata(dev); + + chip->chip_addr_offset_mask = mask; + + return 0; +} + +uint i2c_get_chip_addr_offset_mask(struct udevice *dev) +{ + struct dm_i2c_chip *chip = dev_get_parent_platdata(dev); + + return chip->chip_addr_offset_mask; +} + #ifdef CONFIG_DM_GPIO static void i2c_gpio_set_pin(struct gpio_desc *pin, int bit) { diff --git a/include/i2c.h b/include/i2c.h index 33570f5404..72e2e8e426 100644 --- a/include/i2c.h +++ b/include/i2c.h @@ -45,12 +45,26 @@ struct udevice; * 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) + * @chip_addr_offset_mask: Mask of offset bits within chip_addr. Used for + * devices which steal addresses as part of offset. + * If offset_len is zero, then the offset is encoded + * completely within the chip address itself. + * e.g. a devce with chip address of 0x2c with 512 + * registers might use the bottom bit of the address + * to indicate which half of the address space is being + * accessed while still only using 1 byte offset. + * This means it will respond to chip address 0x2c and + * 0x2d. + * A real world example is the Atmel AT24C04. It's + * datasheet explains it's usage of this addressing + * mode. * @emul: Emulator for this chip address (only used for emulation) */ struct dm_i2c_chip { uint chip_addr; uint offset_len; uint flags; + uint chip_addr_offset_mask; #ifdef CONFIG_SANDBOX struct udevice *emul; bool test_mode; @@ -262,6 +276,25 @@ int i2c_set_chip_offset_len(struct udevice *dev, uint offset_len); int i2c_get_chip_offset_len(struct udevice *dev); /** + * i2c_set_chip_addr_offset_mask() - set mask of address bits usable by offset + * + * Some devices listen on multiple chip addresses to achieve larger offsets + * than their single or multiple byte offsets would allow for. You can use this + * function to set the bits that are valid to be used for offset overflow. + * + * @mask: The mask to be used for high offset bits within address + * @return 0 if OK, other -ve value on error + */ +int i2c_set_chip_addr_offset_mask(struct udevice *dev, uint mask); + +/* + * i2c_get_chip_addr_offset_mask() - get mask of address bits usable by offset + * + * @return current chip addr offset mask + */ +uint i2c_get_chip_addr_offset_mask(struct udevice *dev); + +/** * i2c_deblock() - recover a bus that is in an unknown state * * See the deblock() method in 'struct dm_i2c_ops' for full information |