ssb: Make the GPIO API reentrancy safe

This fixes the GPIO API to be reentrancy safe.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

6 files changed, 122 insertions, 11 deletions

diff --git a/drivers/ssb/driver_chipcommon.c b/drivers/ssb/driver_chipcommon.c
index 7ea0c0faa9ab..e586321a473a 100644
--- a/drivers/ssb/driver_chipcommon.c
+++ b/drivers/ssb/driver_chipcommon.c
@@ -357,37 +357,31 @@ u32 ssb_chipco_gpio_in(struct ssb_chipcommon *cc, u32 mask)
 {
         return chipco_read32(cc, SSB_CHIPCO_GPIOIN) & mask;
 }
-EXPORT_SYMBOL(ssb_chipco_gpio_in);
 
 u32 ssb_chipco_gpio_out(struct ssb_chipcommon *cc, u32 mask, u32 value)
 {
         return chipco_write32_masked(cc, SSB_CHIPCO_GPIOOUT, mask, value);
 }
-EXPORT_SYMBOL(ssb_chipco_gpio_out);
 
 u32 ssb_chipco_gpio_outen(struct ssb_chipcommon *cc, u32 mask, u32 value)
 {
         return chipco_write32_masked(cc, SSB_CHIPCO_GPIOOUTEN, mask, value);
 }
-EXPORT_SYMBOL(ssb_chipco_gpio_outen);
 
 u32 ssb_chipco_gpio_control(struct ssb_chipcommon *cc, u32 mask, u32 value)
 {
         return chipco_write32_masked(cc, SSB_CHIPCO_GPIOCTL, mask, value);
 }
-EXPORT_SYMBOL(ssb_chipco_gpio_control);
 
 u32 ssb_chipco_gpio_intmask(struct ssb_chipcommon *cc, u32 mask, u32 value)
 {
         return chipco_write32_masked(cc, SSB_CHIPCO_GPIOIRQ, mask, value);
 }
-EXPORT_SYMBOL(ssb_chipco_gpio_intmask);
 
 u32 ssb_chipco_gpio_polarity(struct ssb_chipcommon *cc, u32 mask, u32 value)
 {
         return chipco_write32_masked(cc, SSB_CHIPCO_GPIOPOL, mask, value);
 }
-EXPORT_SYMBOL(ssb_chipco_gpio_polarity);
 
 #ifdef CONFIG_SSB_SERIAL
 int ssb_chipco_serial_init(struct ssb_chipcommon *cc,
diff --git a/drivers/ssb/driver_extif.c b/drivers/ssb/driver_extif.c
index 10c6b287f8bb..c3e1d3e6d610 100644
--- a/drivers/ssb/driver_extif.c
+++ b/drivers/ssb/driver_extif.c
@@ -122,30 +122,25 @@ u32 ssb_extif_gpio_in(struct ssb_extif *extif, u32 mask)
 {
         return extif_read32(extif, SSB_EXTIF_GPIO_IN) & mask;
 }
-EXPORT_SYMBOL(ssb_extif_gpio_in);
 
 u32 ssb_extif_gpio_out(struct ssb_extif *extif, u32 mask, u32 value)
 {
         return extif_write32_masked(extif, SSB_EXTIF_GPIO_OUT(0),
                                    mask, value);
 }
-EXPORT_SYMBOL(ssb_extif_gpio_out);
 
 u32 ssb_extif_gpio_outen(struct ssb_extif *extif, u32 mask, u32 value)
 {
         return extif_write32_masked(extif, SSB_EXTIF_GPIO_OUTEN(0),
                                    mask, value);
 }
-EXPORT_SYMBOL(ssb_extif_gpio_outen);
 
 u32 ssb_extif_gpio_polarity(struct ssb_extif *extif, u32 mask, u32 value)
 {
         return extif_write32_masked(extif, SSB_EXTIF_GPIO_INTPOL, mask, value);
 }
-EXPORT_SYMBOL(ssb_extif_gpio_polarity);
 
 u32 ssb_extif_gpio_intmask(struct ssb_extif *extif, u32 mask, u32 value)
 {
         return extif_write32_masked(extif, SSB_EXTIF_GPIO_INTMASK, mask, value);
 }
-EXPORT_SYMBOL(ssb_extif_gpio_intmask);
diff --git a/drivers/ssb/embedded.c b/drivers/ssb/embedded.c
index 751f58ac612c..d3ade821555c 100644
--- a/drivers/ssb/embedded.c
+++ b/drivers/ssb/embedded.c
@@ -11,6 +11,8 @@
 #include <linux/ssb/ssb.h>
 #include <linux/ssb/ssb_embedded.h>
 
+#include "ssb_private.h"
+
 
 int ssb_watchdog_timer_set(struct ssb_bus *bus, u32 ticks)
 {
@@ -24,3 +26,107 @@ int ssb_watchdog_timer_set(struct ssb_bus *bus, u32 ticks)
         }
         return -ENODEV;
 }
+
+u32 ssb_gpio_in(struct ssb_bus *bus, u32 mask)
+{
+        unsigned long flags;
+        u32 res = 0;
+
+        spin_lock_irqsave(&bus->gpio_lock, flags);
+        if (ssb_chipco_available(&bus->chipco))
+                res = ssb_chipco_gpio_in(&bus->chipco, mask);
+        else if (ssb_extif_available(&bus->extif))
+                res = ssb_extif_gpio_in(&bus->extif, mask);
+        else
+                SSB_WARN_ON(1);
+        spin_unlock_irqrestore(&bus->gpio_lock, flags);
+
+        return res;
+}
+EXPORT_SYMBOL(ssb_gpio_in);
+
+u32 ssb_gpio_out(struct ssb_bus *bus, u32 mask, u32 value)
+{
+        unsigned long flags;
+        u32 res = 0;
+
+        spin_lock_irqsave(&bus->gpio_lock, flags);
+        if (ssb_chipco_available(&bus->chipco))
+                res = ssb_chipco_gpio_out(&bus->chipco, mask, value);
+        else if (ssb_extif_available(&bus->extif))
+                res = ssb_extif_gpio_out(&bus->extif, mask, value);
+        else
+                SSB_WARN_ON(1);
+        spin_unlock_irqrestore(&bus->gpio_lock, flags);
+
+        return res;
+}
+EXPORT_SYMBOL(ssb_gpio_out);
+
+u32 ssb_gpio_outen(struct ssb_bus *bus, u32 mask, u32 value)
+{
+        unsigned long flags;
+        u32 res = 0;
+
+        spin_lock_irqsave(&bus->gpio_lock, flags);
+        if (ssb_chipco_available(&bus->chipco))
+                res = ssb_chipco_gpio_outen(&bus->chipco, mask, value);
+        else if (ssb_extif_available(&bus->extif))
+                res = ssb_extif_gpio_outen(&bus->extif, mask, value);
+        else
+                SSB_WARN_ON(1);
+        spin_unlock_irqrestore(&bus->gpio_lock, flags);
+
+        return res;
+}
+EXPORT_SYMBOL(ssb_gpio_outen);
+
+u32 ssb_gpio_control(struct ssb_bus *bus, u32 mask, u32 value)
+{
+        unsigned long flags;
+        u32 res = 0;
+
+        spin_lock_irqsave(&bus->gpio_lock, flags);
+        if (ssb_chipco_available(&bus->chipco))
+                res = ssb_chipco_gpio_control(&bus->chipco, mask, value);
+        spin_unlock_irqrestore(&bus->gpio_lock, flags);
+
+        return res;
+}
+EXPORT_SYMBOL(ssb_gpio_control);
+
+u32 ssb_gpio_intmask(struct ssb_bus *bus, u32 mask, u32 value)
+{
+        unsigned long flags;
+        u32 res = 0;
+
+        spin_lock_irqsave(&bus->gpio_lock, flags);
+        if (ssb_chipco_available(&bus->chipco))
+                res = ssb_chipco_gpio_intmask(&bus->chipco, mask, value);
+        else if (ssb_extif_available(&bus->extif))
+                res = ssb_extif_gpio_intmask(&bus->extif, mask, value);
+        else
+                SSB_WARN_ON(1);
+        spin_unlock_irqrestore(&bus->gpio_lock, flags);
+
+        return res;
+}
+EXPORT_SYMBOL(ssb_gpio_intmask);
+
+u32 ssb_gpio_polarity(struct ssb_bus *bus, u32 mask, u32 value)
+{
+        unsigned long flags;
+        u32 res = 0;
+
+        spin_lock_irqsave(&bus->gpio_lock, flags);
+        if (ssb_chipco_available(&bus->chipco))
+                res = ssb_chipco_gpio_polarity(&bus->chipco, mask, value);
+        else if (ssb_extif_available(&bus->extif))
+                res = ssb_extif_gpio_polarity(&bus->extif, mask, value);
+        else
+                SSB_WARN_ON(1);
+        spin_unlock_irqrestore(&bus->gpio_lock, flags);
+
+        return res;
+}
+EXPORT_SYMBOL(ssb_gpio_polarity);
diff --git a/drivers/ssb/main.c b/drivers/ssb/main.c
index 9028ed5715a1..af07ab22708f 100644
--- a/drivers/ssb/main.c
+++ b/drivers/ssb/main.c
@@ -569,6 +569,9 @@ static int ssb_bus_register(struct ssb_bus *bus,
 
         spin_lock_init(&bus->bar_lock);
         INIT_LIST_HEAD(&bus->list);
+#ifdef CONFIG_SSB_EMBEDDED
+        spin_lock_init(&bus->gpio_lock);
+#endif
 
         /* Powerup the bus */
         err = ssb_pci_xtal(bus, SSB_GPIO_XTAL | SSB_GPIO_PLL, 1);
diff --git a/include/linux/ssb/ssb.h b/include/linux/ssb/ssb.h
index 9d5da8b2ccf9..d14c03685717 100644
--- a/include/linux/ssb/ssb.h
+++ b/include/linux/ssb/ssb.h
@@ -283,6 +283,11 @@ struct ssb_bus {
         /* Contents of the SPROM. */
         struct ssb_sprom sprom;
 
+#ifdef CONFIG_SSB_EMBEDDED
+        /* Lock for GPIO register access. */
+        spinlock_t gpio_lock;
+#endif /* EMBEDDED */
+
         /* Internal-only stuff follows. Do not touch. */
         struct list_head list;
 #ifdef CONFIG_SSB_DEBUG
diff --git a/include/linux/ssb/ssb_embedded.h b/include/linux/ssb/ssb_embedded.h
index 80bd58496450..8d8dedff059d 100644
--- a/include/linux/ssb/ssb_embedded.h
+++ b/include/linux/ssb/ssb_embedded.h
@@ -7,4 +7,12 @@
 
 extern int ssb_watchdog_timer_set(struct ssb_bus *bus, u32 ticks);
 
+/* Generic GPIO API */
+u32 ssb_gpio_in(struct ssb_bus *bus, u32 mask);
+u32 ssb_gpio_out(struct ssb_bus *bus, u32 mask, u32 value);
+u32 ssb_gpio_outen(struct ssb_bus *bus, u32 mask, u32 value);
+u32 ssb_gpio_control(struct ssb_bus *bus, u32 mask, u32 value);
+u32 ssb_gpio_intmask(struct ssb_bus *bus, u32 mask, u32 value);
+u32 ssb_gpio_polarity(struct ssb_bus *bus, u32 mask, u32 value);
+
 #endif /* LINUX_SSB_EMBEDDED_H_ */