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 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 2 adds a generic driver to support CAN transceivers.

changes since v4:
- In patch 3 made the correction from mcan to CAN, in Kconfig help

changes since v3:
- dropped patch 2(in v3)
- changed the node name property in patch 3(in v3)
- picked up Rob Herring's reviewed-by for patch 3(in v3)

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

Aswath Govindraju (3):
  phy: core: Reword the comment specifying the units of max_link_rate to
    be Mbps
  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 ++++++++++++++++++
 include/linux/phy/phy.h                       |   2 +-
 6 files changed, 215 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
 create mode 100644 drivers/phy/phy-can-transceiver.c

-- 
2.17.1

Hi all,

On 16/04/21 5:00 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 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 2 adds a generic driver to support CAN transceivers.
> 
> changes since v4:
> - In patch 3 made the correction from mcan to CAN, in Kconfig help
> 
> changes since v3:
> - dropped patch 2(in v3)
> - changed the node name property in patch 3(in v3)
> - picked up Rob Herring's reviewed-by for patch 3(in v3)
> 
> 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 v6 of this series after making small changes in patch 3 which
include copyright right year change and web address change to https.

Thanks,
Aswath


> Aswath Govindraju (3):
>   phy: core: Reword the comment specifying the units of max_link_rate to
>     be Mbps
>   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 ++++++++++++++++++
>  include/linux/phy/phy.h                       |   2 +-
>  6 files changed, 215 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
>  create mode 100644 drivers/phy/phy-can-transceiver.c
>