spi/of: Create new device registration method and accessors

Dynamically inserting spi device nodes requires the use of a single
device registration method. Refactor the existing
of_register_spi_devices() to split out the core functionality for a
single device into a separate function; of_register_spi_device(). This
function will be used by the OF_DYNAMIC overlay code to make live
modifications to the tree.

Methods to lookup a device/master using a device node are added
as well, of_find_spi_master_by_node() & of_find_spi_device_by_node().

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
[grant.likely] Split patch into two pieces for clarity
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Cc: <linux-spi@vger.kernel.org>

1 files changed, 118 insertions, 104 deletions

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index ebcb33df2eb2..a3557c57d4f7 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1220,6 +1220,121 @@ err_init_queue:
 /*-------------------------------------------------------------------------*/
 
 #if defined(CONFIG_OF)
+static struct spi_device *
+of_register_spi_device(struct spi_master *master, struct device_node *nc)
+{
+        struct spi_device *spi;
+        int rc;
+        u32 value;
+
+        /* 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);
+                rc = -ENOMEM;
+                goto err_out;
+        }
+
+        /* Select device driver */
+        rc = of_modalias_node(nc, spi->modalias,
+                                sizeof(spi->modalias));
+        if (rc < 0) {
+                dev_err(&master->dev, "cannot find modalias for %s\n",
+                        nc->full_name);
+                goto err_out;
+        }
+
+        /* Device address */
+        rc = of_property_read_u32(nc, "reg", &value);
+        if (rc) {
+                dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
+                        nc->full_name, rc);
+                goto err_out;
+        }
+        spi->chip_select = value;
+
+        /* 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;
+        if (of_find_property(nc, "spi-cs-high", NULL))
+                spi->mode |= SPI_CS_HIGH;
+        if (of_find_property(nc, "spi-3wire", NULL))
+                spi->mode |= SPI_3WIRE;
+        if (of_find_property(nc, "spi-lsb-first", NULL))
+                spi->mode |= SPI_LSB_FIRST;
+
+        /* Device DUAL/QUAD mode */
+        if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
+                switch (value) {
+                case 1:
+                        break;
+                case 2:
+                        spi->mode |= SPI_TX_DUAL;
+                        break;
+                case 4:
+                        spi->mode |= SPI_TX_QUAD;
+                        break;
+                default:
+                        dev_warn(&master->dev,
+                                "spi-tx-bus-width %d not supported\n",
+                                value);
+                        break;
+                }
+        }
+
+        if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
+                switch (value) {
+                case 1:
+                        break;
+                case 2:
+                        spi->mode |= SPI_RX_DUAL;
+                        break;
+                case 4:
+                        spi->mode |= SPI_RX_QUAD;
+                        break;
+                default:
+                        dev_warn(&master->dev,
+                                "spi-rx-bus-width %d not supported\n",
+                                value);
+                        break;
+                }
+        }
+
+        /* Device speed */
+        rc = of_property_read_u32(nc, "spi-max-frequency", &value);
+        if (rc) {
+                dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
+                        nc->full_name, rc);
+                goto err_out;
+        }
+        spi->max_speed_hz = value;
+
+        /* 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.of_node = nc;
+
+        /* Register the new device */
+        request_module("%s%s", SPI_MODULE_PREFIX, spi->modalias);
+        rc = spi_add_device(spi);
+        if (rc) {
+                dev_err(&master->dev, "spi_device register error %s\n",
+                        nc->full_name);
+                goto err_out;
+        }
+
+        return spi;
+
+err_out:
+        spi_dev_put(spi);
+        return ERR_PTR(rc);
+}
+
 /**
  * of_register_spi_devices() - Register child devices onto the SPI bus
  * @master:     Pointer to spi_master device
@@ -1231,116 +1346,15 @@ static void of_register_spi_devices(struct spi_master *master)
 {
         struct spi_device *spi;
         struct device_node *nc;
-        int rc;
-        u32 value;
 
         if (!master->dev.of_node)
                 return;
 
         for_each_available_child_of_node(master->dev.of_node, nc) {
-                /* Alloc an spi_device */
-                spi = spi_alloc_device(master);
-                if (!spi) {
-                        dev_err(&master->dev, "spi_device alloc error for %s\n",
+                spi = of_register_spi_device(master, nc);
+                if (IS_ERR(spi))
+                        dev_warn(&master->dev, "Failed to create SPI device 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 */
-                rc = of_property_read_u32(nc, "reg", &value);
-                if (rc) {
-                        dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
-                                nc->full_name, rc);
-                        spi_dev_put(spi);
-                        continue;
-                }
-                spi->chip_select = value;
-
-                /* 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;
-                if (of_find_property(nc, "spi-cs-high", NULL))
-                        spi->mode |= SPI_CS_HIGH;
-                if (of_find_property(nc, "spi-3wire", NULL))
-                        spi->mode |= SPI_3WIRE;
-                if (of_find_property(nc, "spi-lsb-first", NULL))
-                        spi->mode |= SPI_LSB_FIRST;
-
-                /* Device DUAL/QUAD mode */
-                if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
-                        switch (value) {
-                        case 1:
-                                break;
-                        case 2:
-                                spi->mode |= SPI_TX_DUAL;
-                                break;
-                        case 4:
-                                spi->mode |= SPI_TX_QUAD;
-                                break;
-                        default:
-                                dev_warn(&master->dev,
-                                         "spi-tx-bus-width %d not supported\n",
-                                         value);
-                                break;
-                        }
-                }
-
-                if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
-                        switch (value) {
-                        case 1:
-                                break;
-                        case 2:
-                                spi->mode |= SPI_RX_DUAL;
-                                break;
-                        case 4:
-                                spi->mode |= SPI_RX_QUAD;
-                                break;
-                        default:
-                                dev_warn(&master->dev,
-                                         "spi-rx-bus-width %d not supported\n",
-                                         value);
-                                break;
-                        }
-                }
-
-                /* Device speed */
-                rc = of_property_read_u32(nc, "spi-max-frequency", &value);
-                if (rc) {
-                        dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
-                                nc->full_name, rc);
-                        spi_dev_put(spi);
-                        continue;
-                }
-                spi->max_speed_hz = value;
-
-                /* 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.of_node = nc;
-
-                /* Register the new device */
-                request_module("%s%s", SPI_MODULE_PREFIX, 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);
-                }
-
         }
 }
 #else