Re: [PATCH v3 0/4] CAN TRANSCEIVER: Add support for CAN transceivers

[Aswath Govindraju]

Hi all,

On 15/04/21 8:19 pm, Aswath Govindraju wrote:
> The following series of patches add support for CAN transceivers.
> 
> TCAN1042 has a standby signal that needs to be pulled high for
> sending/receiving messages[1]. TCAN1043 has a enable signal along with
> standby signal that needs to be pulled up for sending/receiving
> messages[2], and other combinations of the two lines can be used to put the
> transceiver in different states to reduce power consumption. On boards
> like the AM654-idk and J721e-evm these signals are controlled using gpios.
> 
> Patch 1 rewords the comment that restricts max_link_rate attribute to have
> units of Mbps.
> 
> Patch 2 adds an API for devm_of_phy_optional_get_by_index
> 
> Patch 3 models the transceiver as a phy device tree node with properties
> for max bit rate supported, gpio properties for indicating gpio pin numbers
> to which standby and enable signals are connected.
> 
> Patch 4 adds a generic driver to support CAN transceivers.
> 
> changes since v2:
> - dropped 5 and 6 patches and to be sent via linux-can-next
> - added static keyword for can_transceiver_phy_probe()
> - changed enable gpio example to active high in patch 3
> - Rearranged the file names in alphabetical order in Makefile
>   and MAINTAINERS file
> 
> changes since v1:
> - Added patch 1 (in v2) that rewords the comment that restrict
>   max_link_rate attribute to have units of Mbps.
> - Added patch 2 (in v2) that adds an API for
>   devm_of_phy_optional_get_by_index
> - Patch 1 (in v1)
>   - updated MAINTAINERS file
> - Patch 2 (in v1)
>   - replaced m_can with CAN to make the driver independent of CAN driver
>   - Added prefix CAN_TRANSCEIVER for EN_PRESENT and STB_PRESENT
>   - Added new line before return statements in power_on() and power_off
>   - Added error handling patch for devm_kzalloc()
>   - used the max_link_rate attribute directly instead of dividing it by
>     1000000
>   - removed the spaces before GPIOD_OUT_LOW in devm_gpiod_get()
>   - Corrected requested value for standby-gpios to GPIOD_OUT_HIGH
>   - Updated MAINTAINERS file
> - Patch 3 (in v1)
>   - replaced minItems with maxItems
>   - Removed phy-names property as there is only one phy
> - Patch 4 (in v1)
>   - replaced dev_warn with dev_info when no transceiver is found
>   - Added struct phy * field in m_can_classdev struct
>   - moved phy_power_on and phy_power_off to m_can_open and m_can_close
>     respectively
>   - Moved the check for max_bit_rate to generice transceiver driver
> 
> [1] - https://www.ti.com/lit/ds/symlink/tcan1042h.pdf
> [2] - https://www.ti.com/lit/ds/symlink/tcan1043-q1.pdf
> 

Posted v4 for this series.

Thanks,
Aswath

> Aswath Govindraju (4):
>   phy: core: Reword the comment specifying the units of max_link_rate to
>     be Mbps
>   phy: Add API for devm_of_phy_optional_get_by_index
>   dt-bindings: phy: Add binding for TI TCAN104x CAN transceivers
>   phy: phy-can-transceiver: Add support for generic CAN transceiver
>     driver
> 
>  .../bindings/phy/ti,tcan104x-can.yaml         |  56 +++++++
>  MAINTAINERS                                   |   2 +
>  drivers/phy/Kconfig                           |   9 ++
>  drivers/phy/Makefile                          |   1 +
>  drivers/phy/phy-can-transceiver.c             | 146 ++++++++++++++++++
>  drivers/phy/phy-core.c                        |  26 ++++
>  include/linux/phy/phy.h                       |   4 +-
>  7 files changed, 243 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
>  create mode 100644 drivers/phy/phy-can-transceiver.c
>