From c44a1b91753e54a9e9381ac6411ec36389d21453 Mon Sep 17 00:00:00 2001 From: Bruno Thomsen Date: Thu, 30 Jul 2020 21:57:46 +0200 Subject: [PATCH 1/4] dt-bindings: net: mdio: add reset-post-delay-us property Add "reset-post-delay-us" parameter to MDIO bus properties, so it's possible to add a delay after reset deassert. This is optional in case external hardware slows down release of the reset signal. Signed-off-by: Bruno Thomsen Reviewed-by: Andrew Lunn Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- Documentation/devicetree/bindings/net/mdio.yaml | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Documentation/devicetree/bindings/net/mdio.yaml b/Documentation/devicetree/bindings/net/mdio.yaml index d6a3bf8550eb5..26afb556dfae6 100644 --- a/Documentation/devicetree/bindings/net/mdio.yaml +++ b/Documentation/devicetree/bindings/net/mdio.yaml @@ -39,6 +39,13 @@ properties: and must therefore be appropriately determined based on all devices requirements (maximum value of all per-device RESET pulse widths). + reset-post-delay-us: + description: + Delay after reset deassert in microseconds. It applies to all MDIO + devices and it's determined by how fast all devices are ready for + communication. This delay happens just before e.g. Ethernet PHY + type ID auto detection. + clock-frequency: description: Desired MDIO bus clock frequency in Hz. Values greater than IEEE 802.3 From 6259e0f5478d7a7e4ff3e38bc739b612b8907246 Mon Sep 17 00:00:00 2001 From: Bruno Thomsen Date: Thu, 30 Jul 2020 21:57:47 +0200 Subject: [PATCH 2/4] net: mdiobus: use flexible sleeping for reset-delay-us MDIO bus reset pulse width is created by using udelay() and that function might not be optimal depending on device tree value. By switching to the new fsleep() helper the correct delay function is called depending on delay length, e.g. udelay(), usleep_range() or msleep(). Signed-off-by: Bruno Thomsen Reviewed-by: Andrew Lunn Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/phy/mdio_bus.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 46b33701ad4b0..5df3782b05b4c 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -554,7 +554,7 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner) bus->reset_gpiod = gpiod; gpiod_set_value_cansleep(gpiod, 1); - udelay(bus->reset_delay_us); + fsleep(bus->reset_delay_us); gpiod_set_value_cansleep(gpiod, 0); } From bb3831294cd50750806f2ce8d73317dc8feeda09 Mon Sep 17 00:00:00 2001 From: Bruno Thomsen Date: Thu, 30 Jul 2020 21:57:48 +0200 Subject: [PATCH 3/4] net: mdiobus: add reset-post-delay-us handling Load new "reset-post-delay-us" value from MDIO properties, and if configured to a greater then zero delay do a flexible sleeping delay after MDIO bus reset deassert. This allows devices to exit reset state before start bus communication. Signed-off-by: Bruno Thomsen Reviewed-by: Andrew Lunn Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/phy/mdio_bus.c | 2 ++ drivers/of/of_mdio.c | 2 ++ include/linux/phy.h | 2 ++ 3 files changed, 6 insertions(+) diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 5df3782b05b4c..0af20faad69df 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -556,6 +556,8 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner) gpiod_set_value_cansleep(gpiod, 1); fsleep(bus->reset_delay_us); gpiod_set_value_cansleep(gpiod, 0); + if (bus->reset_post_delay_us > 0) + fsleep(bus->reset_post_delay_us); } if (bus->reset) { diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c index eb84507de28ae..cb32d7ef49382 100644 --- a/drivers/of/of_mdio.c +++ b/drivers/of/of_mdio.c @@ -268,6 +268,8 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np) /* Get bus level PHY reset GPIO details */ mdio->reset_delay_us = DEFAULT_GPIO_RESET_DELAY; of_property_read_u32(np, "reset-delay-us", &mdio->reset_delay_us); + mdio->reset_post_delay_us = 0; + of_property_read_u32(np, "reset-post-delay-us", &mdio->reset_post_delay_us); /* Register the MDIO bus */ rc = mdiobus_register(mdio); diff --git a/include/linux/phy.h b/include/linux/phy.h index 0403eb7999132..3a09d2bf69ea4 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -293,6 +293,8 @@ struct mii_bus { /* GPIO reset pulse width in microseconds */ int reset_delay_us; + /* GPIO reset deassert delay in microseconds */ + int reset_post_delay_us; /* RESET GPIO descriptor pointer */ struct gpio_desc *reset_gpiod; From e4d5efdd0bc43c63c64021147175800a1d58114f Mon Sep 17 00:00:00 2001 From: Bruno Thomsen Date: Thu, 30 Jul 2020 21:57:49 +0200 Subject: [PATCH 4/4] net: mdio device: use flexible sleeping in reset function MDIO device reset assert and deassert length was created by usleep_range() but that does not ensure optimal handling of all the different values from device tree properties. By switching to the new flexible sleeping helper function, fsleep(), the correct delay function is called depending on delay length, e.g. udelay(), usleep_range() or msleep(). Signed-off-by: Bruno Thomsen Reviewed-by: Andrew Lunn Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/phy/mdio_device.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/phy/mdio_device.c b/drivers/net/phy/mdio_device.c index 0f625a1b16447..0837319a52d75 100644 --- a/drivers/net/phy/mdio_device.c +++ b/drivers/net/phy/mdio_device.c @@ -132,7 +132,7 @@ void mdio_device_reset(struct mdio_device *mdiodev, int value) d = value ? mdiodev->reset_assert_delay : mdiodev->reset_deassert_delay; if (d) - usleep_range(d, d + max_t(unsigned int, d / 10, 100)); + fsleep(d); } EXPORT_SYMBOL(mdio_device_reset);