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>

1 files changed, 19 insertions, 1 deletions

diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
index b0704a883513..226977f78482 100644
--- 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;