Blackfin arch: implement support for /proc/dma

Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

1 files changed, 40 insertions, 4 deletions

diff --git a/arch/blackfin/kernel/bfin_dma_5xx.c b/arch/blackfin/kernel/bfin_dma_5xx.c
index a778bc80dc52..2625aa20a92c 100644
--- a/arch/blackfin/kernel/bfin_dma_5xx.c
+++ b/arch/blackfin/kernel/bfin_dma_5xx.c
@@ -29,7 +29,9 @@
 
 #include <linux/errno.h>
 #include <linux/module.h>
+#include <linux/proc_fs.h>
 #include <linux/sched.h>
+#include <linux/seq_file.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/param.h>
@@ -67,26 +69,60 @@ static int __init blackfin_dma_init(void)
                 mutex_init(&(dma_ch[i].dmalock));
         }
         /* Mark MEMDMA Channel 0 as requested since we're using it internally */
-        dma_ch[CH_MEM_STREAM0_DEST].chan_status = DMA_CHANNEL_REQUESTED;
-        dma_ch[CH_MEM_STREAM0_SRC].chan_status = DMA_CHANNEL_REQUESTED;
+        request_dma(CH_MEM_STREAM0_DEST, "Blackfin dma_memcpy");
+        request_dma(CH_MEM_STREAM0_SRC, "Blackfin dma_memcpy");
 
 #if defined(CONFIG_DEB_DMA_URGENT)
         bfin_write_EBIU_DDRQUE(bfin_read_EBIU_DDRQUE()
                          | DEB1_URGENT | DEB2_URGENT | DEB3_URGENT);
 #endif
+
         return 0;
 }
-
 arch_initcall(blackfin_dma_init);
 
+#ifdef CONFIG_PROC_FS
+
+static int proc_dma_show(struct seq_file *m, void *v)
+{
+        int i;
+
+        for (i = 0 ; i < MAX_BLACKFIN_DMA_CHANNEL; ++i)
+                if (dma_ch[i].chan_status != DMA_CHANNEL_FREE)
+                        seq_printf(m, "%2d: %s\n", i, dma_ch[i].device_id);
+
+        return 0;
+}
+
+static int proc_dma_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, proc_dma_show, NULL);
+}
+
+static const struct file_operations proc_dma_operations = {
+        .open           = proc_dma_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
+static int __init proc_dma_init(void)
+{
+        return proc_create("dma", 0, NULL, &proc_dma_operations) != NULL;
+}
+late_initcall(proc_dma_init);
+#endif
+
 /*------------------------------------------------------------------------------
  *      Request the specific DMA channel from the system.
  *-----------------------------------------------------------------------------*/
 int request_dma(unsigned int channel, char *device_id)
 {
-
         pr_debug("request_dma() : BEGIN \n");
 
+        if (device_id == NULL)
+                printk(KERN_WARNING "request_dma(%u): no device_id given\n", channel);
+
 #if defined(CONFIG_BF561) && ANOMALY_05000182
         if (channel >= CH_IMEM_STREAM0_DEST && channel <= CH_IMEM_STREAM1_DEST) {
                 if (get_cclk() > 500000000) {