2022-03-09 06:13:06

by Aswath Govindraju

[permalink] [raw]
Subject: [PATCH v4] phy: phy-can-transceiver: Add support for setting mux

On some boards, for routing CAN signals from controller to transceiver,
muxes might need to be set. Therefore, add support for setting the mux by
reading the mux-states property from the device tree node.

Signed-off-by: Aswath Govindraju <[email protected]>
---

Changes since v3:
- Rebased on top of the linux-next head
- Dependencies are now merged in linux next.
84564481bc45 (mux: Add support for reading mux state from consumer DT node)
- Dropped bindings patch from the series since it has been
picked up from the earlier version
https://lore.kernel.org/all/[email protected]/

Changes since v2:
- Fixed the bindings removing the description about
the arguments in mux-states property

Changes since v1:
- Fixed the description for mux-states property in bindings
file
- appended declaration of variable ret in the end

drivers/phy/Kconfig | 1 +
drivers/phy/phy-can-transceiver.c | 24 +++++++++++++++++++++++-
2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 82b63e60c5a2..300b0f2b5f84 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -64,6 +64,7 @@ config USB_LGM_PHY
config PHY_CAN_TRANSCEIVER
tristate "CAN transceiver PHY"
select GENERIC_PHY
+ select MULTIPLEXER
help
This option enables support for CAN transceivers as a PHY. This
driver provides function for putting the transceivers in various
diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c
index 6f3fe37dee0e..95c6dbb52da7 100644
--- a/drivers/phy/phy-can-transceiver.c
+++ b/drivers/phy/phy-can-transceiver.c
@@ -10,6 +10,7 @@
#include<linux/module.h>
#include<linux/gpio.h>
#include<linux/gpio/consumer.h>
+#include <linux/mux/consumer.h>

struct can_transceiver_data {
u32 flags;
@@ -21,13 +22,22 @@ struct can_transceiver_phy {
struct phy *generic_phy;
struct gpio_desc *standby_gpio;
struct gpio_desc *enable_gpio;
+ struct mux_state *mux_state;
};

/* Power on function */
static int can_transceiver_phy_power_on(struct phy *phy)
{
struct can_transceiver_phy *can_transceiver_phy = phy_get_drvdata(phy);
-
+ int ret;
+
+ if (can_transceiver_phy->mux_state) {
+ ret = mux_state_select(can_transceiver_phy->mux_state);
+ if (ret) {
+ dev_err(&phy->dev, "Failed to select CAN mux: %d\n", ret);
+ return ret;
+ }
+ }
if (can_transceiver_phy->standby_gpio)
gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 0);
if (can_transceiver_phy->enable_gpio)
@@ -45,6 +55,8 @@ static int can_transceiver_phy_power_off(struct phy *phy)
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);
+ if (can_transceiver_phy->mux_state)
+ mux_state_deselect(can_transceiver_phy->mux_state);

return 0;
}
@@ -95,6 +107,16 @@ static int can_transceiver_phy_probe(struct platform_device *pdev)
match = of_match_node(can_transceiver_phy_ids, pdev->dev.of_node);
drvdata = match->data;

+ if (of_property_read_bool(dev->of_node, "mux-states")) {
+ struct mux_state *mux_state;
+
+ mux_state = devm_mux_state_get(dev, NULL);
+ if (IS_ERR(mux_state))
+ return dev_err_probe(&pdev->dev, PTR_ERR(mux_state),
+ "failed to get mux\n");
+ can_transceiver_phy->mux_state = mux_state;
+ }
+
phy = devm_phy_create(dev, dev->of_node,
&can_transceiver_phy_ops);
if (IS_ERR(phy)) {
--
2.17.1