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 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
Add binding documentation for TI TCAN104x CAN transceivers.
Signed-off-by: Aswath Govindraju <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
---
.../bindings/phy/ti,tcan104x-can.yaml | 56 +++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 57 insertions(+)
create mode 100644 Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
diff --git a/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml b/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
new file mode 100644
index 000000000000..6107880e5246
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/phy/ti,tcan104x-can.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: TCAN104x CAN TRANSCEIVER PHY
+
+maintainers:
+ - Aswath Govindraju <[email protected]>
+
+properties:
+ $nodename:
+ pattern: "^can-phy"
+
+ compatible:
+ enum:
+ - ti,tcan1042
+ - ti,tcan1043
+
+ '#phy-cells':
+ const: 0
+
+ standby-gpios:
+ description:
+ gpio node to toggle standby signal on transceiver
+ maxItems: 1
+
+ enable-gpios:
+ description:
+ gpio node to toggle enable signal on transceiver
+ maxItems: 1
+
+ max-bitrate:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ max bit rate supported in bps
+ minimum: 1
+
+required:
+ - compatible
+ - '#phy-cells'
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+
+ transceiver1: can-phy {
+ compatible = "ti,tcan1043";
+ #phy-cells = <0>;
+ max-bitrate = <5000000>;
+ standby-gpios = <&wakeup_gpio1 16 GPIO_ACTIVE_LOW>;
+ enable-gpios = <&main_gpio1 67 GPIO_ACTIVE_HIGH>;
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index 84ef96a444c3..e666d33af10d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4046,6 +4046,7 @@ W: https://github.com/linux-can
T: git git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can.git
T: git git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git
F: Documentation/devicetree/bindings/net/can/
+F: Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
F: drivers/net/can/
F: include/linux/can/bittiming.h
F: include/linux/can/dev.h
--
2.17.1
The driver adds support for generic CAN transceivers. Currently
the modes supported by this driver are standby and normal modes for TI
TCAN1042 and TCAN1043 CAN transceivers.
The transceiver is modelled as a phy with pins controlled by gpios, to put
the transceiver in various device functional modes. It also gets the phy
attribute max_link_rate for the usage of CAN drivers.
Signed-off-by: Aswath Govindraju <[email protected]>
---
MAINTAINERS | 1 +
drivers/phy/Kconfig | 9 ++
drivers/phy/Makefile | 1 +
drivers/phy/phy-can-transceiver.c | 146 ++++++++++++++++++++++++++++++
4 files changed, 157 insertions(+)
create mode 100644 drivers/phy/phy-can-transceiver.c
diff --git a/MAINTAINERS b/MAINTAINERS
index e666d33af10d..4e868f2a97c7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4048,6 +4048,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git
F: Documentation/devicetree/bindings/net/can/
F: Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
F: drivers/net/can/
+F: drivers/phy/phy-can-transceiver.c
F: include/linux/can/bittiming.h
F: include/linux/can/dev.h
F: include/linux/can/led.h
diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 54c1f2f0985f..51902b629fc6 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -61,6 +61,15 @@ config USB_LGM_PHY
interface to interact with USB GEN-II and USB 3.x PHY that is part
of the Intel network SOC.
+config PHY_CAN_TRANSCEIVER
+ tristate "CAN transceiver PHY"
+ select GENERIC_PHY
+ help
+ This option enables support for CAN transceivers as a PHY. This
+ driver provides function for putting the transceivers in various
+ functional modes using gpios and sets the attribute max link
+ rate, for mcan drivers.
+
source "drivers/phy/allwinner/Kconfig"
source "drivers/phy/amlogic/Kconfig"
source "drivers/phy/broadcom/Kconfig"
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index adac1b1a39d1..01e9efffc726 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -5,6 +5,7 @@
obj-$(CONFIG_GENERIC_PHY) += phy-core.o
obj-$(CONFIG_GENERIC_PHY_MIPI_DPHY) += phy-core-mipi-dphy.o
+obj-$(CONFIG_PHY_CAN_TRANSCEIVER) += phy-can-transceiver.o
obj-$(CONFIG_PHY_LPC18XX_USB_OTG) += phy-lpc18xx-usb-otg.o
obj-$(CONFIG_PHY_XGENE) += phy-xgene.o
obj-$(CONFIG_PHY_PISTACHIO_USB) += phy-pistachio-usb.o
diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c
new file mode 100644
index 000000000000..c24aa2eab9e4
--- /dev/null
+++ b/drivers/phy/phy-can-transceiver.c
@@ -0,0 +1,146 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * phy-can-transceiver.c - phy driver for CAN transceivers
+ *
+ * Copyright (C) 2021 Texas Instruments Incorporated - http://www.ti.com
+ *
+ */
+#include<linux/phy/phy.h>
+#include<linux/platform_device.h>
+#include<linux/module.h>
+#include<linux/gpio.h>
+#include<linux/gpio/consumer.h>
+
+struct can_transceiver_data {
+ u32 flags;
+#define CAN_TRANSCEIVER_STB_PRESENT BIT(0)
+#define CAN_TRANSCEIVER_EN_PRESENT BIT(1)
+};
+
+struct can_transceiver_phy {
+ struct phy *generic_phy;
+ struct gpio_desc *standby_gpio;
+ struct gpio_desc *enable_gpio;
+};
+
+/* Power on function */
+static int can_transceiver_phy_power_on(struct phy *phy)
+{
+ struct can_transceiver_phy *can_transceiver_phy = phy_get_drvdata(phy);
+
+ if (can_transceiver_phy->standby_gpio)
+ gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 0);
+ if (can_transceiver_phy->enable_gpio)
+ gpiod_set_value_cansleep(can_transceiver_phy->enable_gpio, 1);
+
+ return 0;
+}
+
+/* Power off function */
+static int can_transceiver_phy_power_off(struct phy *phy)
+{
+ struct can_transceiver_phy *can_transceiver_phy = phy_get_drvdata(phy);
+
+ if (can_transceiver_phy->standby_gpio)
+ gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 1);
+ if (can_transceiver_phy->enable_gpio)
+ gpiod_set_value_cansleep(can_transceiver_phy->enable_gpio, 0);
+
+ return 0;
+}
+
+static const struct phy_ops can_transceiver_phy_ops = {
+ .power_on = can_transceiver_phy_power_on,
+ .power_off = can_transceiver_phy_power_off,
+ .owner = THIS_MODULE,
+};
+
+static const struct can_transceiver_data tcan1042_drvdata = {
+ .flags = CAN_TRANSCEIVER_STB_PRESENT,
+};
+
+static const struct can_transceiver_data tcan1043_drvdata = {
+ .flags = CAN_TRANSCEIVER_STB_PRESENT | CAN_TRANSCEIVER_EN_PRESENT,
+};
+
+static const struct of_device_id can_transceiver_phy_ids[] = {
+ {
+ .compatible = "ti,tcan1042",
+ .data = &tcan1042_drvdata
+ },
+ {
+ .compatible = "ti,tcan1043",
+ .data = &tcan1043_drvdata
+ },
+ { }
+};
+MODULE_DEVICE_TABLE(of, can_transceiver_phy_ids);
+
+static int can_transceiver_phy_probe(struct platform_device *pdev)
+{
+ struct phy_provider *phy_provider;
+ struct device *dev = &pdev->dev;
+ struct can_transceiver_phy *can_transceiver_phy;
+ const struct can_transceiver_data *drvdata;
+ const struct of_device_id *match;
+ struct phy *phy;
+ struct gpio_desc *standby_gpio;
+ struct gpio_desc *enable_gpio;
+ u32 max_bitrate = 0;
+
+ can_transceiver_phy = devm_kzalloc(dev, sizeof(struct can_transceiver_phy), GFP_KERNEL);
+ if (!can_transceiver_phy)
+ return -ENOMEM;
+
+ match = of_match_node(can_transceiver_phy_ids, pdev->dev.of_node);
+ drvdata = match->data;
+
+ phy = devm_phy_create(dev, dev->of_node,
+ &can_transceiver_phy_ops);
+ if (IS_ERR(phy)) {
+ dev_err(dev, "failed to create can transceiver phy\n");
+ return PTR_ERR(phy);
+ }
+
+ device_property_read_u32(dev, "max-bitrate", &max_bitrate);
+ if (!max_bitrate)
+ dev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit\n");
+ phy->attrs.max_link_rate = max_bitrate;
+
+ can_transceiver_phy->generic_phy = phy;
+
+ if (drvdata->flags & CAN_TRANSCEIVER_STB_PRESENT) {
+ standby_gpio = devm_gpiod_get(dev, "standby", GPIOD_OUT_HIGH);
+ if (IS_ERR(standby_gpio))
+ return PTR_ERR(standby_gpio);
+ can_transceiver_phy->standby_gpio = standby_gpio;
+ }
+
+ if (drvdata->flags & CAN_TRANSCEIVER_EN_PRESENT) {
+ enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
+ if (IS_ERR(enable_gpio))
+ return PTR_ERR(enable_gpio);
+ can_transceiver_phy->enable_gpio = enable_gpio;
+ }
+
+ phy_set_drvdata(can_transceiver_phy->generic_phy, can_transceiver_phy);
+
+ phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+ return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static struct platform_driver can_transceiver_phy_driver = {
+ .probe = can_transceiver_phy_probe,
+ .driver = {
+ .name = "can-transceiver-phy",
+ .of_match_table = can_transceiver_phy_ids,
+ },
+};
+
+module_platform_driver(can_transceiver_phy_driver);
+
+MODULE_AUTHOR("Faiz Abbas <[email protected]>");
+MODULE_AUTHOR("Aswath Govindraju <[email protected]>");
+MODULE_DESCRIPTION("CAN TRANSCEIVER PHY driver");
+MODULE_LICENSE("GPL v2");
--
2.17.1
On 16.04.2021 10:56:47, Aswath Govindraju wrote:
> The driver adds support for generic CAN transceivers. Currently
> the modes supported by this driver are standby and normal modes for TI
> TCAN1042 and TCAN1043 CAN transceivers.
>
> The transceiver is modelled as a phy with pins controlled by gpios, to put
> the transceiver in various device functional modes. It also gets the phy
> attribute max_link_rate for the usage of CAN drivers.
>
> Signed-off-by: Aswath Govindraju <[email protected]>
> ---
> MAINTAINERS | 1 +
> drivers/phy/Kconfig | 9 ++
> drivers/phy/Makefile | 1 +
> drivers/phy/phy-can-transceiver.c | 146 ++++++++++++++++++++++++++++++
> 4 files changed, 157 insertions(+)
> create mode 100644 drivers/phy/phy-can-transceiver.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e666d33af10d..4e868f2a97c7 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -4048,6 +4048,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git
> F: Documentation/devicetree/bindings/net/can/
> F: Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
> F: drivers/net/can/
> +F: drivers/phy/phy-can-transceiver.c
> F: include/linux/can/bittiming.h
> F: include/linux/can/dev.h
> F: include/linux/can/led.h
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index 54c1f2f0985f..51902b629fc6 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -61,6 +61,15 @@ config USB_LGM_PHY
> interface to interact with USB GEN-II and USB 3.x PHY that is part
> of the Intel network SOC.
>
> +config PHY_CAN_TRANSCEIVER
> + tristate "CAN transceiver PHY"
> + select GENERIC_PHY
> + help
> + This option enables support for CAN transceivers as a PHY. This
> + driver provides function for putting the transceivers in various
> + functional modes using gpios and sets the attribute max link
> + rate, for mcan drivers.
^^^^
CAN
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
Hi all,
On 16/04/21 10:56 am, 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 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 v5 for this series.
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
>