basic_mmio_gpio: allow overriding number of gpio

Some platforms may have a number of GPIO that is less than the register
width of the peripheral.

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

diff --git a/drivers/gpio/basic_mmio_gpio.c b/drivers/gpio/basic_mmio_gpio.c
index 5db5de4..2b2d384 100644 (file)
--- a/drivers/gpio/basic_mmio_gpio.c
+++ b/drivers/gpio/basic_mmio_gpio.c
@@ -239,6 +239,7 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
        resource_size_t dat_sz;
        int bits;
        int ret;
+       int ngpio;
 
        res_dat = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
        if (!res_dat)
@@ -249,6 +250,7 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
                return -EINVAL;
 
        bits = dat_sz * 8;
+       ngpio = bits;
        if (bits > BITS_PER_LONG)
                return -EINVAL;
 
@@ -277,13 +279,22 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
 
        spin_lock_init(&bgc->lock);
 
+       if (pdata) {
+               bgc->gc.base = pdata->base;
+               if (pdata->ngpio > 0)
+                       ngpio = pdata->ngpio;
+       } else {
+               bgc->gc.base = -1;
+       }
+
        bgc->bits = bits;
        ret = bgpio_setup_accessors(pdev, bgc);
        if (ret)
                return ret;
 
        bgc->data = bgc->read_reg(bgc->reg_dat);
-       bgc->gc.ngpio = bits;
+
+       bgc->gc.ngpio = ngpio;
        bgc->gc.direction_input = bgpio_dir_in;
        bgc->gc.direction_output = bgpio_dir_out;
        bgc->gc.get = bgpio_get;
@@ -291,11 +302,6 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
        bgc->gc.dev = dev;
        bgc->gc.label = dev_name(dev);
 
-       if (pdata)
-               bgc->gc.base = pdata->base;
-       else
-               bgc->gc.base = -1;
-
        platform_set_drvdata(pdev, bgc);
 
        ret = gpiochip_add(&bgc->gc);

diff --git a/include/linux/basic_mmio_gpio.h b/include/linux/basic_mmio_gpio.h
index 198087a..f23ec73 100644 (file)
--- a/include/linux/basic_mmio_gpio.h
+++ b/include/linux/basic_mmio_gpio.h
@@ -15,6 +15,7 @@
 
 struct bgpio_pdata {
        int base;
+       int ngpio;
 };
 
 #endif /* __BASIC_MMIO_GPIO_H */