diff mbox series

[2/2] usb: usb251xb: make power-up reset delay configurable in device tree

Message ID 20220426123329.775-3-du@axentia.se
State New
Headers show
Series [1/2] dt-bindings: usb: usb251xb: add documentation for reset-delay-us | expand

Commit Message

Daniels Umanovskis April 26, 2022, 12:34 p.m. UTC 
According to the datasheet, the hub should be operational 500us after
the reset has been deasserted. Some individual circuits have been
observed not to reset within the specified 500us and require a longer
wait for subsequent configuration to succeed.

Signed-off-by: Daniels Umanovskis <du@axentia.se>
---
 drivers/usb/misc/usb251xb.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/usb/misc/usb251xb.c b/drivers/usb/misc/usb251xb.c
index 04c4e3fed094..e287e241ef96 100644
--- a/drivers/usb/misc/usb251xb.c
+++ b/drivers/usb/misc/usb251xb.c
@@ -115,6 +115,7 @@  struct usb251xb {
 	struct regulator *vdd;
 	u8 skip_config;
 	struct gpio_desc *gpio_reset;
+	u32 reset_delay_us;
 	u16 vendor_id;
 	u16 product_id;
 	u16 device_id;
@@ -278,7 +279,7 @@  static void usb251xb_reset(struct usb251xb *hub)
 	gpiod_set_value_cansleep(hub->gpio_reset, 0);
 
 	/* wait for hub recovery/stabilization */
-	usleep_range(500, 750);	/* >=500us after RESET_N deasserted */
+	fsleep(hub->reset_delay_us);
 
 	i2c_unlock_bus(hub->i2c->adapter, I2C_LOCK_SEGMENT);
 }
@@ -424,6 +425,9 @@  static int usb251xb_get_ofdata(struct usb251xb *hub,
 		return err;
 	}
 
+	if (of_property_read_u32(np, "reset-delay-us", &hub->reset_delay_us))
+		hub->reset_delay_us = 500;
+
 	if (of_property_read_u16_array(np, "vendor-id", &hub->vendor_id, 1))
 		hub->vendor_id = USB251XB_DEF_VENDOR_ID;