DMA: shdma: add DT support

This patch adds Device Tree support to the shdma driver. No special DT
properties are used, only standard DMA DT bindings are implemented. Since
shdma controllers reside on SoCs, their configuration is SoC-specific and
shall be passed to the driver from the SoC platform data, using the
auxdata procedure.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 25 insertions, 6 deletions

diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c
index a5a1887c34b5..b67f45f5c271 100644
--- a/drivers/dma/sh/shdma.c
+++ b/drivers/dma/sh/shdma.c
@@ -301,20 +301,32 @@ static void sh_dmae_setup_xfer(struct shdma_chan *schan,
         }
 }
 
+/*
+ * Find a slave channel configuration from the contoller list by either a slave
+ * ID in the non-DT case, or by a MID/RID value in the DT case
+ */
 static const struct sh_dmae_slave_config *dmae_find_slave(
-        struct sh_dmae_chan *sh_chan, int slave_id)
+        struct sh_dmae_chan *sh_chan, int match)
 {
         struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
         struct sh_dmae_pdata *pdata = shdev->pdata;
         const struct sh_dmae_slave_config *cfg;
         int i;
 
-        if (slave_id >= SH_DMA_SLAVE_NUMBER)
-                return NULL;
+        if (!sh_chan->shdma_chan.dev->of_node) {
+                if (match >= SH_DMA_SLAVE_NUMBER)
+                        return NULL;
 
-        for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++)
-                if (cfg->slave_id == slave_id)
-                        return cfg;
+                for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++)
+                        if (cfg->slave_id == match)
+                                return cfg;
+        } else {
+                for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++)
+                        if (cfg->mid_rid == match) {
+                                sh_chan->shdma_chan.slave_id = cfg->slave_id;
+                                return cfg;
+                        }
+        }
 
         return NULL;
 }
@@ -920,11 +932,18 @@ static int sh_dmae_remove(struct platform_device *pdev)
         return 0;
 }
 
+static const struct of_device_id sh_dmae_of_match[] = {
+        { .compatible = "renesas,shdma", },
+        { }
+};
+MODULE_DEVICE_TABLE(of, sh_dmae_of_match);
+
 static struct platform_driver sh_dmae_driver = {
         .driver         = {
                 .owner  = THIS_MODULE,
                 .pm     = &sh_dmae_pm,
                 .name   = SH_DMAE_DRV_NAME,
+                .of_match_table = sh_dmae_of_match,
         },
         .remove         = sh_dmae_remove,
         .shutdown       = sh_dmae_shutdown,