MIPS: BCM47XX: Get GPIO pin from nvram configuration

The nvram contains some gpio configuration for boards. It is stored in
a gpio<number>=name format e.g.
gpio8=wps_button
gpio4=robo_reset

This patches adds a function to parse these entries, so other driver
can use it.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5841/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/arch/mips/bcm47xx/nvram.c b/arch/mips/bcm47xx/nvram.c
index cc40b74940f5..b4c585b1c62e 100644
--- a/arch/mips/bcm47xx/nvram.c
+++ b/arch/mips/bcm47xx/nvram.c
@@ -190,3 +190,23 @@ int bcm47xx_nvram_getenv(char *name, char *val, size_t val_len)
         return -ENOENT;
 }
 EXPORT_SYMBOL(bcm47xx_nvram_getenv);
+
+int bcm47xx_nvram_gpio_pin(const char *name)
+{
+        int i, err;
+        char nvram_var[10];
+        char buf[30];
+
+        for (i = 0; i < 16; i++) {
+                err = snprintf(nvram_var, sizeof(nvram_var), "gpio%i", i);
+                if (err <= 0)
+                        continue;
+                err = bcm47xx_nvram_getenv(nvram_var, buf, sizeof(buf));
+                if (err <= 0)
+                        continue;
+                if (!strcmp(name, buf))
+                        return i;
+        }
+        return -ENOENT;
+}
+EXPORT_SYMBOL(bcm47xx_nvram_gpio_pin);