1 files changed, 93 insertions, 0 deletions

diff --git a/drivers/of/of_spi.c b/drivers/of/of_spi.c
new file mode 100644
index 000000000000..b01eec026f68
--- /dev/null
+++ b/drivers/of/of_spi.c
@@ -0,0 +1,93 @@
+/*
+ * SPI OF support routines
+ * Copyright (C) 2008 Secret Lab Technologies Ltd.
+ *
+ * Support routines for deriving SPI device attachments from the device
+ * tree.
+ */
+
+#include <linux/of.h>
+#include <linux/device.h>
+#include <linux/spi/spi.h>
+#include <linux/of_spi.h>
+
+/**
+ * of_register_spi_devices - Register child devices onto the SPI bus
+ * @master:     Pointer to spi_master device
+ * @np:         parent node of SPI device nodes
+ *
+ * Registers an spi_device for each child node of 'np' which has a 'reg'
+ * property.
+ */
+void of_register_spi_devices(struct spi_master *master, struct device_node *np)
+{
+        struct spi_device *spi;
+        struct device_node *nc;
+        const u32 *prop;
+        int rc;
+        int len;
+
+        for_each_child_of_node(np, nc) {
+                /* Alloc an spi_device */
+                spi = spi_alloc_device(master);
+                if (!spi) {
+                        dev_err(&master->dev, "spi_device alloc error for %s\n",
+                                nc->full_name);
+                        spi_dev_put(spi);
+                        continue;
+                }
+
+                /* Select device driver */
+                if (of_modalias_node(nc, spi->modalias,
+                                     sizeof(spi->modalias)) < 0) {
+                        dev_err(&master->dev, "cannot find modalias for %s\n",
+                                nc->full_name);
+                        spi_dev_put(spi);
+                        continue;
+                }
+
+                /* Device address */
+                prop = of_get_property(nc, "reg", &len);
+                if (!prop || len < sizeof(*prop)) {
+                        dev_err(&master->dev, "%s has no 'reg' property\n",
+                                nc->full_name);
+                        spi_dev_put(spi);
+                        continue;
+                }
+                spi->chip_select = *prop;
+
+                /* Mode (clock phase/polarity/etc.) */
+                if (of_find_property(nc, "spi-cpha", NULL))
+                        spi->mode |= SPI_CPHA;
+                if (of_find_property(nc, "spi-cpol", NULL))
+                        spi->mode |= SPI_CPOL;
+
+                /* Device speed */
+                prop = of_get_property(nc, "spi-max-frequency", &len);
+                if (!prop || len < sizeof(*prop)) {
+                        dev_err(&master->dev, "%s has no 'spi-max-frequency' property\n",
+                                nc->full_name);
+                        spi_dev_put(spi);
+                        continue;
+                }
+                spi->max_speed_hz = *prop;
+
+                /* IRQ */
+                spi->irq = irq_of_parse_and_map(nc, 0);
+
+                /* Store a pointer to the node in the device structure */
+                of_node_get(nc);
+                spi->dev.archdata.of_node = nc;
+
+                /* Register the new device */
+                request_module(spi->modalias);
+                rc = spi_add_device(spi);
+                if (rc) {
+                        dev_err(&master->dev, "spi_device register error %s\n",
+                                nc->full_name);
+                        spi_dev_put(spi);
+                }
+
+        }
+}
+EXPORT_SYMBOL(of_register_spi_devices);