From: "A.s. Dong" <aisheng.dong@nxp.com>
Date: Sat, 10 Nov 2018 14:21:18 +0000
Subject: gpio: vf610: add optional clock support
Git-commit: 91393622bca33cac70175e0fdc5a3ec8f9efe08b
Patch-mainline: v5.0-rc1
References: FATE#326248

Some SoCs need the gpio clock to be enabled before accessing
HW registers. This patch add the optional clock handling.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: linux-gpio@vger.kernel.org
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
 drivers/gpio/gpio-vf610.c |   44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

--- a/drivers/gpio/gpio-vf610.c
+++ b/drivers/gpio/gpio-vf610.c
@@ -16,6 +16,7 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/gpio.h>
 #include <linux/init.h>
@@ -35,6 +36,8 @@ struct vf610_gpio_port {
 	void __iomem *base;
 	void __iomem *gpio_base;
 	u8 irqc[VF610_GPIO_PER_PORT];
+	struct clk *clk_port;
+	struct clk *clk_gpio;
 	int irq;
 };
 
@@ -241,6 +244,33 @@ static int vf610_gpio_probe(struct platf
 	if (port->irq < 0)
 		return port->irq;
 
+	port->clk_port = devm_clk_get(&pdev->dev, "port");
+	if (!IS_ERR(port->clk_port)) {
+		ret = clk_prepare_enable(port->clk_port);
+		if (ret)
+			return ret;
+	} else if (port->clk_port == ERR_PTR(-EPROBE_DEFER)) {
+		/*
+		 * Percolate deferrals, for anything else,
+		 * just live without the clocking.
+		 */
+		return PTR_ERR(port->clk_port);
+	}
+
+	port->clk_gpio = devm_clk_get(&pdev->dev, "gpio");
+	if (!IS_ERR(port->clk_gpio)) {
+		ret = clk_prepare_enable(port->clk_gpio);
+		if (ret) {
+			clk_disable_unprepare(port->clk_port);
+			return ret;
+		}
+	} else if (port->clk_gpio == ERR_PTR(-EPROBE_DEFER)) {
+		clk_disable_unprepare(port->clk_port);
+		return PTR_ERR(port->clk_gpio);
+	}
+
+	platform_set_drvdata(pdev, port);
+
 	gc = &port->gc;
 	gc->of_node = np;
 	gc->parent = dev;
@@ -275,12 +305,26 @@ static int vf610_gpio_probe(struct platf
 	return 0;
 }
 
+static int vf610_gpio_remove(struct platform_device *pdev)
+{
+	struct vf610_gpio_port *port = platform_get_drvdata(pdev);
+
+	gpiochip_remove(&port->gc);
+	if (!IS_ERR(port->clk_port))
+		clk_disable_unprepare(port->clk_port);
+	if (!IS_ERR(port->clk_gpio))
+		clk_disable_unprepare(port->clk_gpio);
+
+	return 0;
+}
+
 static struct platform_driver vf610_gpio_driver = {
 	.driver		= {
 		.name	= "gpio-vf610",
 		.of_match_table = vf610_gpio_dt_ids,
 	},
 	.probe		= vf610_gpio_probe,
+	.remove		= vf610_gpio_remove,
 };
 
 builtin_platform_driver(vf610_gpio_driver);