spi/sh-msiof: Add device tree parsing to driver

This adds the capability to retrieve setup data from the device tree
node. The usage of platform data is still available.

Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

2 files changed, 67 insertions, 1 deletions

diff --git a/Documentation/devicetree/bindings/spi/sh-msiof.txt b/Documentation/devicetree/bindings/spi/sh-msiof.txt
new file mode 100644
index 000000000000..e6222106ca36
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/sh-msiof.txt
@@ -0,0 +1,12 @@
+Renesas MSIOF spi controller
+
+Required properties:
+- compatible :  "renesas,sh-msiof" for SuperH or
+                "renesas,sh-mobile-msiof" for SH Mobile series
+- reg : Offset and length of the register set for the device
+- interrupts : interrupt line used by MSIOF
+
+Optional properties:
+- num-cs                : total number of chip-selects
+- renesas,tx-fifo-size  : Overrides the default tx fifo size given in words
+- renesas,rx-fifo-size  : Overrides the default rx fifo size given in words
diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index 96358d0eabb7..8b40d0884f8b 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -20,6 +20,7 @@
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 
@@ -592,6 +593,37 @@ static u32 sh_msiof_spi_txrx_word(struct spi_device *spi, unsigned nsecs,
         return 0;
 }
 
+#ifdef CONFIG_OF
+static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
+{
+        struct sh_msiof_spi_info *info;
+        struct device_node *np = dev->of_node;
+        u32 num_cs = 0;
+
+        info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
+        if (!info) {
+                dev_err(dev, "failed to allocate setup data\n");
+                return NULL;
+        }
+
+        /* Parse the MSIOF properties */
+        of_property_read_u32(np, "num-cs", &num_cs);
+        of_property_read_u32(np, "renesas,tx-fifo-size",
+                                        &info->tx_fifo_override);
+        of_property_read_u32(np, "renesas,rx-fifo-size",
+                                        &info->rx_fifo_override);
+
+        info->num_chipselect = num_cs;
+
+        return info;
+}
+#else
+static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
+{
+        return NULL;
+}
+#endif
+
 static int sh_msiof_spi_probe(struct platform_device *pdev)
 {
         struct resource *r;
@@ -610,7 +642,17 @@ static int sh_msiof_spi_probe(struct platform_device *pdev)
         p = spi_master_get_devdata(master);
 
         platform_set_drvdata(pdev, p);
-        p->info = pdev->dev.platform_data;
+        if (pdev->dev.of_node)
+                p->info = sh_msiof_spi_parse_dt(&pdev->dev);
+        else
+                p->info = pdev->dev.platform_data;
+
+        if (!p->info) {
+                dev_err(&pdev->dev, "failed to obtain device info\n");
+                ret = -ENXIO;
+                goto err1;
+        }
+
         init_completion(&p->done);
 
         p->clk = clk_get(&pdev->dev, NULL);
@@ -715,6 +757,17 @@ static int sh_msiof_spi_runtime_nop(struct device *dev)
         return 0;
 }
 
+#ifdef CONFIG_OF
+static const struct of_device_id sh_msiof_match[] = {
+        { .compatible = "renesas,sh-msiof", },
+        { .compatible = "renesas,sh-mobile-msiof", },
+        {},
+};
+MODULE_DEVICE_TABLE(of, sh_msiof_match);
+#else
+#define sh_msiof_match NULL
+#endif
+
 static struct dev_pm_ops sh_msiof_spi_dev_pm_ops = {
         .runtime_suspend = sh_msiof_spi_runtime_nop,
         .runtime_resume = sh_msiof_spi_runtime_nop,
@@ -727,6 +780,7 @@ static struct platform_driver sh_msiof_spi_drv = {
                 .name           = "spi_sh_msiof",
                 .owner          = THIS_MODULE,
                 .pm             = &sh_msiof_spi_dev_pm_ops,
+                .of_match_table = sh_msiof_match,
         },
 };
 module_platform_driver(sh_msiof_spi_drv);