[PATCH v2 1/2] net: mdio: Handle bus level GPIO Reset
Roger Quadros
rogerq at kernel.org
Wed Feb 28 11:35:26 CET 2024
Some platforms have bus level Reset controlled
by a GPIO line. If available then handle bus reset
via GPIO.
Signed-off-by: Roger Quadros <rogerq at kernel.org>
---
Changelog:
v2:
- Fix build if DM_GPIO not set
- Fix build on platforms that don't have <asm/gpio.h>
by using <asm-generic/gpio.h>
---
include/phy.h | 7 +++++++
net/mdio-uclass.c | 37 ++++++++++++++++++++++++++++++++++++-
2 files changed, 43 insertions(+), 1 deletion(-)
diff --git a/include/phy.h b/include/phy.h
index e02cbdb58c..ae23814bbf 100644
--- a/include/phy.h
+++ b/include/phy.h
@@ -9,6 +9,7 @@
#ifndef _PHY_H
#define _PHY_H
+#include <asm-generic/gpio.h>
#include <log.h>
#include <phy_interface.h>
#include <dm/ofnode.h>
@@ -76,6 +77,12 @@ struct mii_dev {
int (*reset)(struct mii_dev *bus);
struct phy_device *phymap[PHY_MAX_ADDR];
u32 phy_mask;
+ /** @reset_delay_us: Bus GPIO reset pulse width in microseconds */
+ int reset_delay_us;
+ /** @reset_post_delay_us: Bus GPIO reset deassert delay in microseconds */
+ int reset_post_delay_us;
+ /** @reset_gpiod: Bus Reset GPIO descriptor pointer */
+ struct gpio_desc reset_gpiod;
};
/* struct phy_driver: a structure which defines PHY behavior
diff --git a/net/mdio-uclass.c b/net/mdio-uclass.c
index e758cc66d7..6fc7034111 100644
--- a/net/mdio-uclass.c
+++ b/net/mdio-uclass.c
@@ -14,6 +14,9 @@
#include <dm/of_extra.h>
#include <dm/uclass-internal.h>
#include <linux/compat.h>
+#include <linux/delay.h>
+
+#define DEFAULT_GPIO_RESET_DELAY 10 /* in microseconds */
void dm_mdio_probe_devices(void)
{
@@ -80,6 +83,16 @@ int dm_mdio_write(struct udevice *mdio_dev, int addr, int devad, int reg,
int dm_mdio_reset(struct udevice *mdio_dev)
{
struct mdio_ops *ops = mdio_get_ops(mdio_dev);
+ struct mdio_perdev_priv *pdata = dev_get_uclass_priv(mdio_dev);
+ struct mii_dev *mii_bus = pdata->mii_bus;
+
+ if (CONFIG_IS_ENABLED(DM_GPIO) && dm_gpio_is_valid(&mii_bus->reset_gpiod)) {
+ dm_gpio_set_value(&mii_bus->reset_gpiod, 1);
+ udelay(mii_bus->reset_delay_us);
+ dm_gpio_set_value(&mii_bus->reset_gpiod, 0);
+ if (mii_bus->reset_post_delay_us > 0)
+ udelay(mii_bus->reset_post_delay_us);
+ }
if (!ops->reset)
return 0;
@@ -111,14 +124,36 @@ static int mdio_reset(struct mii_dev *mii_bus)
static int dm_mdio_post_probe(struct udevice *dev)
{
struct mdio_perdev_priv *pdata = dev_get_uclass_priv(dev);
+ struct mii_dev *mii_bus;
+ int ret;
- pdata->mii_bus = mdio_alloc();
+ mii_bus = mdio_alloc();
+ if (!mii_bus) {
+ dev_err(dev, "couldn't allocate mii_bus\n");
+ return -ENOMEM;
+ }
+ pdata->mii_bus = mii_bus;
pdata->mii_bus->read = mdio_read;
pdata->mii_bus->write = mdio_write;
pdata->mii_bus->reset = mdio_reset;
pdata->mii_bus->priv = dev;
strlcpy(pdata->mii_bus->name, dev->name, MDIO_NAME_LEN);
+ if (IS_ENABLED(CONFIG_DM_GPIO)) {
+ /* Get bus level PHY reset GPIO details */
+ mii_bus->reset_delay_us = dev_read_u32_default(dev, "reset-delay-us",
+ DEFAULT_GPIO_RESET_DELAY);
+ mii_bus->reset_post_delay_us = dev_read_u32_default(dev,
+ "reset-post-delay-us",
+ 0);
+ ret = gpio_request_by_name(dev, "reset-gpios", 0, &mii_bus->reset_gpiod,
+ GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
+ if (ret && ret != -ENOENT) {
+ dev_err(dev, "couldn't get reset-gpios: %d\n", ret);
+ return ret;
+ }
+ }
+
return mdio_register(pdata->mii_bus);
}
--
2.34.1
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