Messages in this thread Patch in this message | | | From | Yan Wang <> | Subject | [PATCH v4] net: mdiobus: Add a function to deassert reset | Date | Thu, 11 May 2023 14:59:09 +0800 |
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It is possible to mount multiple sub-devices on the mido bus. The hardware power-on does not necessarily reset these devices. The device may be in an uncertain state, causing the device's ID to not be scanned.
So,before adding a reset to the scan, make sure the device is in normal working mode.
Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202305101702.4xW6vT72-lkp@intel.com/ Signed-off-by: Yan Wang <rk.code@outlook.com> --- v4: - Get pulse width and settling time from the device tree - Add logic for processing (PTR_ERR(reset) == -EPROBE_DEFER) - included <linux/goio/consumer.h> - fixed commit message v3: https://lore.kernel.org/all/KL1PR01MB5448A33A549CDAD7D68945B9E6779@KL1PR01MB5448.apcprd01.prod.exchangelabs.com/ - fixed commit message v2: https://lore.kernel.org/all/KL1PR01MB54482416A8BE0D80EA27223CE6779@KL1PR01MB5448.apcprd01.prod.exchangelabs.com/ - fixed commit message - Using gpiod_ replace gpio_ v1: https://lore.kernel.org/all/KL1PR01MB5448631F2D6F71021602117FE6769@KL1PR01MB5448.apcprd01.prod.exchangelabs.com/ - Incorrect description of commit message. - The gpio-api too old --- drivers/net/mdio/fwnode_mdio.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
diff --git a/drivers/net/mdio/fwnode_mdio.c b/drivers/net/mdio/fwnode_mdio.c index 1183ef5e203e..9d7df6393059 100644 --- a/drivers/net/mdio/fwnode_mdio.c +++ b/drivers/net/mdio/fwnode_mdio.c @@ -11,6 +11,7 @@ #include <linux/of.h> #include <linux/phy.h> #include <linux/pse-pd/pse.h> +#include <linux/gpio/consumer.h> MODULE_AUTHOR("Calvin Johnson <calvin.johnson@oss.nxp.com>"); MODULE_LICENSE("GPL"); @@ -57,6 +58,35 @@ fwnode_find_mii_timestamper(struct fwnode_handle *fwnode) return register_mii_timestamper(arg.np, arg.args[0]); } +static void fwnode_mdiobus_pre_enable_phy(struct fwnode_handle *fwnode) +{ + struct gpio_desc *reset; + unsigned int reset_assert_delay; + unsigned int reset_deassert_delay; + + reset = fwnode_gpiod_get_index(fwnode, "reset", 0, GPIOD_OUT_LOW, NULL); + if (IS_ERR(reset)) { + if (PTR_ERR(reset) == -EPROBE_DEFER) + pr_debug("%pOFn: %s: GPIOs not yet available, retry later\n", + to_of_node(fwnode), __func__); + else + pr_err("%pOFn: %s: Can't get reset line property\n", + to_of_node(fwnode), __func__); + + return; + } + fwnode_property_read_u32(fwnode, "reset-assert-us", + &reset_assert_delay); + fwnode_property_read_u32(fwnode, "reset-deassert-us", + &reset_deassert_delay); + gpiod_set_value_cansleep(reset, 1); + fsleep(reset_assert_delay); + gpiod_set_value_cansleep(reset, 0); + fsleep(reset_deassert_delay); + /*Release phy's reset line, mdiobus_register_gpiod() need to request it*/ + gpiod_put(reset); +} + int fwnode_mdiobus_phy_device_register(struct mii_bus *mdio, struct phy_device *phy, struct fwnode_handle *child, u32 addr) @@ -119,6 +149,8 @@ int fwnode_mdiobus_register_phy(struct mii_bus *bus, u32 phy_id; int rc; + fwnode_mdiobus_pre_enable_phy(child); + psec = fwnode_find_pse_control(child); if (IS_ERR(psec)) return PTR_ERR(psec); -- 2.17.1
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