gpio: vf610: add optional clock support

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>

1 files changed, 44 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-vf610.c b/drivers/gpio/gpio-vf610.c
index 5960396c8d9a..1b79ebcfce3e 100644
--- a/drivers/gpio/gpio-vf610.c
+++ b/drivers/gpio/gpio-vf610.c
@@ -7,6 +7,7 @@
  * Author: Stefan Agner <stefan@agner.ch>.
  */
 #include <linux/bitops.h>
+#include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/gpio/driver.h>
 #include <linux/init.h>
@@ -32,6 +33,8 @@ struct vf610_gpio_port {
         void __iomem *gpio_base;
         const struct fsl_gpio_soc_data *sdata;
         u8 irqc[VF610_GPIO_PER_PORT];
+        struct clk *clk_port;
+        struct clk *clk_gpio;
         int irq;
 };
 
@@ -271,6 +274,33 @@ static int vf610_gpio_probe(struct platform_device *pdev)
         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;
@@ -305,12 +335,26 @@ static int vf610_gpio_probe(struct platform_device *pdev)
         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);