linux-kernel - [PATCH] gpio: mxc: add clock operation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 21 May 2018 18:06:30 +0800
From:   Anson Huang <Anson.Huang@....com>
To:     linus.walleij@...aro.org
Cc:     Linux-imx@....com, linux-gpio@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] gpio: mxc: add clock operation

i.MX6SLL has GPIO clock gates in CCM CCGR, need
to enable them before accessing registers, add
optional clock operation for GPIO driver.

Signed-off-by: Anson Huang <Anson.Huang@....com>
---
 drivers/gpio/gpio-mxc.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c
index 11ec722..8fc37c4 100644
--- a/drivers/gpio/gpio-mxc.c
+++ b/drivers/gpio/gpio-mxc.c
@@ -60,6 +60,7 @@ struct mxc_gpio_hwdata {
 struct mxc_gpio_port {
 	struct list_head node;
 	void __iomem *base;
+	struct clk *clk;
 	int irq;
 	int irq_high;
 	struct irq_domain *domain;
@@ -434,6 +435,17 @@ static int mxc_gpio_probe(struct platform_device *pdev)
 	if (port->irq < 0)
 		return port->irq;
 
+	/* the controller clock is optional */
+	port->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(port->clk))
+		port->clk = NULL;
+
+	err = clk_prepare_enable(port->clk);
+	if (err) {
+		dev_err(&pdev->dev, "Unable to enable clock.\n");
+		return err;
+	}
+
 	/* disable the interrupt and clear the status */
 	writel(0, port->base + GPIO_IMR);
 	writel(~0, port->base + GPIO_ISR);
@@ -502,6 +514,7 @@ static int mxc_gpio_probe(struct platform_device *pdev)
 out_irqdomain_remove:
 	irq_domain_remove(port->domain);
 out_bgio:
+	clk_disable_unprepare(port->clk);
 	dev_info(&pdev->dev, "%s failed with errno %d\n", __func__, err);
 	return err;
 }
-- 
2.7.4