Blackfin arch: Functional power management support

Enable: PM_SUSPEND_MEM -> Blackfin Hibernate to SDRAM
This feature requires a special bootloader (u-boot)
supporting return from hibernate.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/arch/blackfin/kernel/bfin_dma_5xx.c b/arch/blackfin/kernel/bfin_dma_5xx.c
index d54f19085f37..ad0e75845ac2 100644
--- a/arch/blackfin/kernel/bfin_dma_5xx.c
+++ b/arch/blackfin/kernel/bfin_dma_5xx.c
@@ -472,6 +472,32 @@ unsigned long get_dma_curr_addr(unsigned int channel)
 }
 EXPORT_SYMBOL(get_dma_curr_addr);
 
+#ifdef CONFIG_PM
+int blackfin_dma_suspend(void)
+{
+        int i;
+
+        for (i = 0; i < MAX_BLACKFIN_DMA_CHANNEL; i++) {
+                if (dma_ch[i].chan_status == DMA_CHANNEL_ENABLED) {
+                        printk(KERN_ERR "DMA Channel %d failed to suspend\n", i);
+                        return -EBUSY;
+                }
+
+                dma_ch[i].saved_peripheral_map = dma_ch[i].regs->peripheral_map;
+        }
+
+        return 0;
+}
+
+void blackfin_dma_resume(void)
+{
+        int i;
+
+        for (i = 0; i < MAX_BLACKFIN_DMA_CHANNEL; i++)
+                dma_ch[i].regs->peripheral_map = dma_ch[i].saved_peripheral_map;
+}
+#endif
+
 static void *__dma_memcpy(void *dest, const void *src, size_t size)
 {
         int direction;  /* 1 - address decrease, 0 - address increase */