Re: [PATCH net-next 2/2] drivers: net: dsa: mt7530: MT7530 optional GPIO support
From: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Date: 2021-01-11 11:05:19
Also in:
linux-arm-kernel, linux-devicetree, lkml, netdev
On Mon, Jan 11, 2021 at 01:44:28PM +0800, DENG Qingfang wrote:
+static int
+mt7530_gpio_direction_output(struct gpio_chip *gc, unsigned int offset, int value)
+{
+ struct mt7530_priv *priv = gpiochip_get_data(gc);
+ u32 bit = mt7530_gpio_to_bit(offset);
+
+ mt7530_set(priv, MT7530_LED_GPIO_DIR, bit);
+ mt7530_set(priv, MT7530_LED_GPIO_OE, bit);
+ mt7530_gpio_set(gc, offset, value);FYI, Documentation/driver-api/gpio/consumer.rst says: For output GPIOs, the value provided becomes the initial output value. This helps avoid signal glitching during system startup. Setting the pin to be an output, and then setting its initial value does not avoid the glitch. You may wish to investigate whether you can set the value before setting the pin as an output to avoid this issue. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek