[U-Boot] [RFC PATCH 0/12] RFC: dm: Add I2C support

Simon Glass sjg at chromium.org
Mon Oct 13 07:39:26 CEST 2014


(Note this is RFC since the uclass interface needs discussion and also
because only sandbox is implemented so far. But I thought it best to get
this out there as soon as I wrote it as it may influence the PMIC library,
etc.)

This series is an initial attempt to add I2C support to driver model. It
has become apparent that this is a high priority as it is widely used. It
follows along to some extent from the SPI conversion.

Several changes are made from the original I2C implementations.

Firstly It is not necessary to specify the chip address with every call,
since each chip knows its own address - it is stored in struct dm_i2c_chip
which is attached to each chip on the I2C bus. However, this information
*is* passed to the driver since I presume most drivers need it and it would
be cumbersome to look up in every call.

Secondly there is no concept of a 'current' I2C bus so all associated logic
is removed. With driver model i2c_set_bus_num() and i2c_get_bus_num() are
not available. Since the chip device specifies both the bus and the chip
address, there is no need for this concept. It also causes problems when
one driver changes the current bus and forgets to change it back.

Thirdly initialisation is handled by driver model's normal probe() method
on each device so there should be no need for i2c_init_all(), i2c_init(),
i2c_init_board(), i2c_board_late_init() and board_i2c_init().

I2C muxes are not yet supported. To support these we will need to maintain
state of the current mux settings to avoid resetting every mux every time.
Probably we need to add a sandbox I2C mux driver to permit testing of this.
This can probably be done later.

Platform data is not yet supported either, only device tree. The
U_BOOT_I2C_MKENT_COMPLETE() and U_BOOT_I2C_ADAP_COMPLETE() macros are not
used. Also struct i2c_adapter is not defined anymore. This will need to be
addressed, perhaps as part of converting over a board that does not use
device tree.

This series is available at u-boot-dm/i2c-working.


Simon Glass (12):
  dm: core: Allow access to the device's driver_id data
  dm: core: Add functions to find parent and OF data
  dm: i2c: Add a uclass for I2C
  dm: i2c: Implement driver model support in the i2c command
  dm: i2c: Add I2C emulation driver for sandbox
  dm: i2c: Add a sandbox I2C driver
  dm: i2c: Add an I2C EEPROM simulator
  dm: i2c: config: Enable I2C for sandbox using driver model
  dm: i2c: dts: Add an I2C bus for sandbox
  dm: WIP: EEPROM driver
  dm: i2c: Add tests for I2C
  dm: i2c: tegra: Convert to driver model for I2C for seaboard

 arch/arm/cpu/tegra20-common/pmu.c           |  21 +-
 arch/arm/include/asm/arch-tegra/tegra_i2c.h |   2 +-
 arch/sandbox/dts/sandbox.dts                |  17 ++
 board/nvidia/common/board.c                 |   4 -
 common/cmd_i2c.c                            | 312 +++++++++++++++++++++++----
 drivers/core/device.c                       |  10 +
 drivers/core/lists.c                        |  17 +-
 drivers/i2c/Makefile                        |   2 +
 drivers/i2c/i2c-emul-uclass.c               |  14 ++
 drivers/i2c/i2c-uclass.c                    | 177 ++++++++++++++++
 drivers/i2c/sandbox_i2c.c                   | 148 +++++++++++++
 drivers/i2c/tegra_i2c.c                     | 313 ++++++++++------------------
 drivers/misc/Makefile                       |   4 +
 drivers/misc/i2c_eeprom.c                   |  51 +++++
 drivers/misc/i2c_eeprom_emul.c              | 108 ++++++++++
 drivers/power/tps6586x.c                    |  27 +--
 include/config_fallbacks.h                  |   6 +
 include/configs/cardhu.h                    |   2 -
 include/configs/colibri_t30.h               |   2 -
 include/configs/sandbox.h                   |   6 +
 include/configs/seaboard.h                  |   3 -
 include/configs/tegra-common.h              |   1 +
 include/configs/tegra20-common.h            |   3 -
 include/dm/device.h                         |  19 ++
 include/dm/uclass-id.h                      |   3 +
 include/i2c.h                               | 252 ++++++++++++++++++++++
 include/i2c_eeprom.h                        |  19 ++
 include/tps6586x.h                          |   2 +-
 test/dm/Makefile                            |   1 +
 test/dm/i2c.c                               | 100 +++++++++
 test/dm/test.dts                            |  17 ++
 31 files changed, 1373 insertions(+), 290 deletions(-)
 create mode 100644 drivers/i2c/i2c-emul-uclass.c
 create mode 100644 drivers/i2c/i2c-uclass.c
 create mode 100644 drivers/i2c/sandbox_i2c.c
 create mode 100644 drivers/misc/i2c_eeprom.c
 create mode 100644 drivers/misc/i2c_eeprom_emul.c
 create mode 100644 include/i2c_eeprom.h
 create mode 100644 test/dm/i2c.c

-- 
2.1.0.rc2.206.gedb03e5



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