gpiolib: i2c/spi drivers: handle rmmod better

Use the newly introduced owner field in struct gpio_chip to protect the
current (small) set of non-SOC GPIO drivers from being unloaded while any of
their GPIOs are in use.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
[ add mcp23s08 and pcf857x ]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 3 insertions, 0 deletions

diff --git a/drivers/gpio/mcp23s08.c b/drivers/gpio/mcp23s08.c
index bb60e8c1a1f0..7fb5b9d009d4 100644
--- a/drivers/gpio/mcp23s08.c
+++ b/drivers/gpio/mcp23s08.c
@@ -239,6 +239,7 @@ static int mcp23s08_probe(struct spi_device *spi)
         mcp->chip.base = pdata->base;
         mcp->chip.ngpio = 8;
         mcp->chip.can_sleep = 1;
+        mcp->chip.owner = THIS_MODULE;
 
         spi_set_drvdata(spi, mcp);
 
diff --git a/drivers/gpio/pca953x.c b/drivers/gpio/pca953x.c
index 6e72fd31184d..e0e0af536108 100644
--- a/drivers/gpio/pca953x.c
+++ b/drivers/gpio/pca953x.c
@@ -189,6 +189,7 @@ static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
         gc->base = chip->gpio_start;
         gc->ngpio = gpios;
         gc->label = chip->client->name;
+        gc->owner = THIS_MODULE;
 }
 
 static int __devinit pca953x_probe(struct i2c_client *client)
diff --git a/drivers/gpio/pcf857x.c b/drivers/gpio/pcf857x.c
index c6b3b5378384..1106aa15ac79 100644
--- a/drivers/gpio/pcf857x.c
+++ b/drivers/gpio/pcf857x.c
@@ -159,6 +159,7 @@ static int pcf857x_probe(struct i2c_client *client)
 
         gpio->chip.base = pdata->gpio_base;
         gpio->chip.can_sleep = 1;
+        gpio->chip.owner = THIS_MODULE;
 
         /* NOTE:  the OnSemi jlc1562b is also largely compatible with
          * these parts, notably for output.  It has a low-resolution