ARM: pxa: ssp: add pxa_ssp_request_of()

Add a function to lookup ssp devices from device tree. This way, users
can reference the ssp devices in order to register to them.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

2 files changed, 36 insertions, 0 deletions

diff --git a/arch/arm/plat-pxa/ssp.c b/arch/arm/plat-pxa/ssp.c
index f2661355fa4e..c83f27b6bdda 100644
--- a/arch/arm/plat-pxa/ssp.c
+++ b/arch/arm/plat-pxa/ssp.c
@@ -62,6 +62,30 @@ struct ssp_device *pxa_ssp_request(int port, const char *label)
 }
 EXPORT_SYMBOL(pxa_ssp_request);
 
+struct ssp_device *pxa_ssp_request_of(const struct device_node *of_node,
+                                      const char *label)
+{
+        struct ssp_device *ssp = NULL;
+
+        mutex_lock(&ssp_lock);
+
+        list_for_each_entry(ssp, &ssp_list, node) {
+                if (ssp->of_node == of_node && ssp->use_count == 0) {
+                        ssp->use_count++;
+                        ssp->label = label;
+                        break;
+                }
+        }
+
+        mutex_unlock(&ssp_lock);
+
+        if (&ssp->node == &ssp_list)
+                return NULL;
+
+        return ssp;
+}
+EXPORT_SYMBOL(pxa_ssp_request_of);
+
 void pxa_ssp_free(struct ssp_device *ssp)
 {
         mutex_lock(&ssp_lock);
@@ -185,6 +209,7 @@ static int pxa_ssp_probe(struct platform_device *pdev)
         }
 
         ssp->use_count = 0;
+        ssp->of_node = dev->of_node;
 
         mutex_lock(&ssp_lock);
         list_add(&ssp->node, &ssp_list);
diff --git a/include/linux/pxa2xx_ssp.h b/include/linux/pxa2xx_ssp.h
index 467cc6307b62..49444203328a 100644
--- a/include/linux/pxa2xx_ssp.h
+++ b/include/linux/pxa2xx_ssp.h
@@ -21,6 +21,8 @@
 
 #include <linux/list.h>
 #include <linux/io.h>
+#include <linux/of.h>
+
 
 /*
  * SSP Serial Port Registers
@@ -190,6 +192,8 @@ struct ssp_device {
         int             irq;
         int             drcmr_rx;
         int             drcmr_tx;
+
+        struct device_node      *of_node;
 };
 
 /**
@@ -218,11 +222,18 @@ static inline u32 pxa_ssp_read_reg(struct ssp_device *dev, u32 reg)
 #ifdef CONFIG_ARCH_PXA
 struct ssp_device *pxa_ssp_request(int port, const char *label);
 void pxa_ssp_free(struct ssp_device *);
+struct ssp_device *pxa_ssp_request_of(const struct device_node *of_node,
+                                      const char *label);
 #else
 static inline struct ssp_device *pxa_ssp_request(int port, const char *label)
 {
         return NULL;
 }
+static inline struct ssp_device *pxa_ssp_request_of(const struct device_node *n,
+                                                    const char *name)
+{
+        return NULL;
+}
 static inline void pxa_ssp_free(struct ssp_device *ssp) {}
 #endif