basic_mmio_gpio: request register regions

Make sure that we get the register regions with request_mem_region()
before ioremap() to make sure we have exclusive access.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 13 insertions, 3 deletions

diff --git a/drivers/gpio/basic_mmio_gpio.c b/drivers/gpio/basic_mmio_gpio.c
index 2b2d38454463..90f7f8930d5b 100644
--- a/drivers/gpio/basic_mmio_gpio.c
+++ b/drivers/gpio/basic_mmio_gpio.c
@@ -192,6 +192,16 @@ static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
         return 0;
 }
 
+static void __iomem *bgpio_request_and_map(struct device *dev,
+                                           struct resource *res)
+{
+        if (!devm_request_mem_region(dev, res->start, resource_size(res),
+                                     res->name ?: "mmio_gpio"))
+                return NULL;
+
+        return devm_ioremap(dev, res->start, resource_size(res));
+}
+
 static int bgpio_setup_accessors(struct platform_device *pdev,
                                  struct bgpio_chip *bgc)
 {
@@ -258,7 +268,7 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
         if (!bgc)
                 return -ENOMEM;
 
-        bgc->reg_dat = devm_ioremap(dev, res_dat->start, dat_sz);
+        bgc->reg_dat = bgpio_request_and_map(dev, res_dat);
         if (!bgc->reg_dat)
                 return -ENOMEM;
 
@@ -269,8 +279,8 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
                                 resource_size(res_set) != dat_sz)
                         return -EINVAL;
 
-                bgc->reg_set = devm_ioremap(dev, res_set->start, dat_sz);
-                bgc->reg_clr = devm_ioremap(dev, res_clr->start, dat_sz);
+                bgc->reg_set = bgpio_request_and_map(dev, res_set);
+                bgc->reg_clr = bgpio_request_and_map(dev, res_clr);
                 if (!bgc->reg_set || !bgc->reg_clr)
                         return -ENOMEM;
         } else if (res_set || res_clr) {