gpio: dwapb: Add support for a bus clock

Enable an optional bus clock provided by DT.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
index b0704a8..226977f 100644 (file)
--- a/drivers/gpio/gpio-dwapb.c
+++ b/drivers/gpio/gpio-dwapb.c
@@ -8,8 +8,9 @@
  * All enquiries to support@picochip.com
  */
 #include <linux/acpi.h>
-#include <linux/gpio/driver.h>
+#include <linux/clk.h>
 #include <linux/err.h>
+#include <linux/gpio/driver.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -98,6 +99,7 @@ struct dwapb_gpio {
        struct irq_domain       *domain;
        unsigned int            flags;
        struct reset_control    *rst;
+       struct clk              *clk;
 };
 
 static inline u32 gpio_reg_v2_convert(unsigned int offset)
@@ -670,6 +672,16 @@ static int dwapb_gpio_probe(struct platform_device *pdev)
        if (IS_ERR(gpio->regs))
                return PTR_ERR(gpio->regs);
 
+       /* Optional bus clock */
+       gpio->clk = devm_clk_get(&pdev->dev, "bus");
+       if (!IS_ERR(gpio->clk)) {
+               err = clk_prepare_enable(gpio->clk);
+               if (err) {
+                       dev_info(&pdev->dev, "Cannot enable clock\n");
+                       return err;
+               }
+       }
+
        gpio->flags = 0;
        if (dev->of_node) {
                const struct of_device_id *of_devid;
@@ -712,6 +724,7 @@ static int dwapb_gpio_remove(struct platform_device *pdev)
        dwapb_gpio_unregister(gpio);
        dwapb_irq_teardown(gpio);
        reset_control_assert(gpio->rst);
+       clk_disable_unprepare(gpio->clk);
 
        return 0;
 }
@@ -757,6 +770,8 @@ static int dwapb_gpio_suspend(struct device *dev)
        }
        spin_unlock_irqrestore(&gc->bgpio_lock, flags);
 
+       clk_disable_unprepare(gpio->clk);
+
        return 0;
 }
 
@@ -768,6 +783,9 @@ static int dwapb_gpio_resume(struct device *dev)
        unsigned long flags;
        int i;
 
+       if (!IS_ERR(gpio->clk))
+               clk_prepare_enable(gpio->clk);
+
        spin_lock_irqsave(&gc->bgpio_lock, flags);
        for (i = 0; i < gpio->nr_ports; i++) {
                unsigned int offset;