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>

diff --git a/drivers/gpio/gpio-vf610.c b/drivers/gpio/gpio-vf610.c
index 5960396c8d9a263d835f764b4e0f0de95fe06b30..1b79ebcfce3e5c3e9d59d3586155642bf84ef6ad 100644 (file)
--- 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);