Thread (27 messages) 27 messages, 4 authors, 2020-01-05

Re: [PATCH v3 10/16] usb: phy: tegra: Use device-tree notion of reset-GPIO's active-state

From: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Date: 2020-01-03 07:58:11
Also in: linux-devicetree, linux-tegra, lkml

On Sat, Dec 28, 2019 at 11:33:52PM +0300, Dmitry Osipenko wrote:
[...]
 static int ulpi_open(struct tegra_usb_phy *phy)
 {
-	int err;
-
-	err = gpio_direction_output(phy->reset_gpio, 0);
-	if (err) {
-		dev_err(phy->u_phy.dev,
-			"ULPI reset GPIO %d direction not deasserted: %d\n",
-			phy->reset_gpio, err);
-		return err;
-	}
+	gpiod_set_value_cansleep(phy->reset_gpio, 1);
 
 	return 0;
 }
The message now removed seems inverted to the meaning of the code. Is
this a bug, or the reset really should be asserted here? I can see that
it is deasserted in phy_power_up, but that goes before or after ulpi_open()?
After the change below, the reset is asserted at probe() time now.

[...]
-		err = devm_gpio_request(&pdev->dev, tegra_phy->reset_gpio,
-					"ulpi_phy_reset_b");
+		gpiod = devm_gpiod_get_from_of_node(&pdev->dev, np,
+						    "nvidia,phy-reset-gpio",
+						    0, GPIOD_OUT_HIGH,
+						    "ulpi_phy_reset_b");
+		err = PTR_ERR_OR_ZERO(gpiod);
 		if (err) {
-			dev_err(&pdev->dev, "Request failed for GPIO %d: %d\n",
-				tegra_phy->reset_gpio, err);
+			dev_err(&pdev->dev,
+				"Request failed for reset GPIO: %d\n", err);
 			return err;
 		}
+		tegra_phy->reset_gpio = gpiod;
A nice extension to kernel's printf - "%pe" format - has just landed in
Linus' master tree.

Best Regards,
Michał Mirosław
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