linux-kernel - [RFC PATCH 4/7] basic_mmio_gpio: request register regions

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Date:	Wed,  6 Apr 2011 12:11:00 +0100
From:	Jamie Iles <jamie@...ieiles.com>
To:	linux-kernel@...r.kernel.org
Cc:	linux@....linux.org.uk, tglx@...utronix.de, cbouatmailru@...il.com,
	grant.likely@...retlab.ca, arnd@...db.de, nico@...xnic.net,
	Jamie Iles <jamie@...ieiles.com>
Subject: [RFC PATCH 4/7] 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@...ieiles.com>
Cc: Anton Vorontsov <cbouatmailru@...il.com>
Cc: Grant Likely <grant.likely@...retlab.ca>
---
 drivers/gpio/basic_mmio_gpio.c |   16 +++++++++++++---
 1 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/basic_mmio_gpio.c b/drivers/gpio/basic_mmio_gpio.c
index 68f8b8b..afa854b 100644
--- a/drivers/gpio/basic_mmio_gpio.c
+++ b/drivers/gpio/basic_mmio_gpio.c
@@ -193,6 +193,16 @@ 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)
 {
@@ -259,7 +269,7 @@ 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;
 
@@ -270,8 +280,8 @@ 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) {
-- 
1.7.4

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