Add the bus handler registration needed for performing overlays
containing spi devices.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
---
drivers/spi/spi.c | 345 ++++++++++++++++++++++++++++++++++++++----------------
1 file changed, 242 insertions(+), 103 deletions(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 4eb9bf0..dac5573 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1179,6 +1179,123 @@ err_init_queue:
/*-------------------------------------------------------------------------*/
#if defined(CONFIG_OF)
+
+static struct spi_device *
+of_register_spi_device(struct spi_master *master, struct device_node *node)
+{
+ struct spi_device *spi;
+ struct device_node *nc;
+ int err;
+ 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);
+ err = -ENOMEM;
+ goto err_out;
+ }
+
+ /* Select device driver */
+ err = of_modalias_node(nc, spi->modalias,
+ sizeof(spi->modalias));
+ if (err) {
+ dev_err(&master->dev, "cannot find modalias for %s\n",
+ nc->full_name);
+ goto err_out;
+ }
+
+ /* Device address */
+ err = of_property_read_u32(nc, "reg", &value);
+ if (err) {
+ dev_err(&master->dev, "%s has no valid 'reg' property (%d)\n",
+ nc->full_name, err);
+ 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;
+
+ /* 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_err(&master->dev,
+ "spi-tx-bus-width %d not supported\n",
+ value);
+ err = -EINVAL;
+ goto err_out;
+ }
+ }
+
+ 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_err(&master->dev,
+ "spi-rx-bus-width %d not supported\n",
+ value);
+ err = -EINVAL;
+ goto err_out;
+ }
+ }
+
+ /* Device speed */
+ err = of_property_read_u32(nc, "spi-max-frequency", &value);
+ if (err) {
+ dev_err(&master->dev, "%s has no valid 'spi-max-frequency' property (%d)\n",
+ nc->full_name, err);
+ 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);
+ err = spi_add_device(spi);
+ if (err) {
+ 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(err);
+}
+
/**
* of_register_spi_devices() - Register child devices onto the SPI bus
* @master: Pointer to spi_master device
@@ -1188,124 +1305,140 @@ err_init_queue:
*/
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",
- nc->full_name);
- spi_dev_put(spi);
- continue;
- }
+ for_each_available_child_of_node(master->dev.of_node, nc)
+ of_register_spi_device(master, nc);
+}
- /* 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;
- }
+static int of_dev_node_match(struct device *dev, void *data)
+{
+ return dev->of_node == data;
+}
- /* 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;
-
- /* 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_err(&master->dev,
- "spi-tx-bus-width %d not supported\n",
- value);
- spi_dev_put(spi);
- continue;
- }
- }
+/* bah; the match functions differ just by const-ness */
+static int of_dev_node_match_const(struct device *dev, const void *data)
+{
+ return dev->of_node == data;
+}
- 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_err(&master->dev,
- "spi-rx-bus-width %d not supported\n",
- value);
- spi_dev_put(spi);
- continue;
- }
- }
+/* must call put_device() when done with returned spi_device device */
+struct spi_device *of_find_spi_device_by_node(struct device_node *node)
+{
+ struct device *dev;
- /* 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);
- }
+ dev = bus_find_device(&spi_bus_type, NULL, node,
+ of_dev_node_match);
+ if (!dev)
+ return NULL;
+ return to_spi_device(dev);
+}
+EXPORT_SYMBOL(of_find_spi_device_by_node);
+
+/* forward decl */
+static struct class spi_master_class;
+
+/* the spi masters are not using spi_bus, so we have to find it some other way */
+struct spi_master *of_find_spi_master_by_node(struct device_node *node)
+{
+ struct device *dev;
+
+ dev = class_find_device(&spi_master_class, NULL, node,
+ of_dev_node_match_const);
+ if (!dev)
+ return NULL;
+
+ /* reference got in class_find_device */
+ return container_of(dev, struct spi_master, dev);
+}
+EXPORT_SYMBOL(of_find_spi_master_by_node);
+
+#ifdef CONFIG_OF_OVERLAY
+static int spi_handler_create(struct of_overlay_device_entry *de,
+ int revert)
+{
+ struct device_node *dn;
+ struct spi_master *master;
+ struct spi_device *spi;
+
+ if (!de || !de->np)
+ return -ENOTSUPP;
+
+ dn = de->np;
+
+ master = of_find_spi_master_by_node(dn->parent);
+ if (master == NULL)
+ return -ENOTSUPP;
+
+ spi = of_register_spi_device(master, dn);
+ put_device(&master->dev);
+
+ if (spi == NULL) {
+ pr_err("%s: failed to create spi device "
+ "for '%s'\n",
+ __func__, dn->full_name);
+ /* of_register_spi_device tosses the real error code */
+ return -EINVAL;
}
+
+ return 0;
}
+
+static int spi_handler_remove(struct of_overlay_device_entry *de,
+ int revert)
+{
+ struct device_node *dn;
+ struct spi_device *spi;
+
+ if (!de || !de->np)
+ return -ENOTSUPP;
+
+ dn = de->np;
+
+ spi = of_find_spi_device_by_node(dn);
+ if (spi == NULL)
+ return -ENOTSUPP;
+
+ /* unregister takes one ref away */
+ spi_unregister_device(spi);
+
+ /* and put the reference of the find */
+ put_device(&spi->dev);
+
+ return 0;
+}
+
+static const struct of_overlay_handler_ops spi_handler_ops = {
+ .create = spi_handler_create,
+ .remove = spi_handler_remove,
+};
+
+static struct of_overlay_handler spi_handler = {
+ .name = "spi",
+ .ops = &spi_handler_ops,
+};
+
+static int __init spi_bus_handler_register(void)
+{
+ return of_overlay_handler_register(&spi_handler);
+}
+#endif
+
#else
static void of_register_spi_devices(struct spi_master *master) { }
#endif
+#if !defined(CONFIG_OF) || !defined(CONFIG_OF_OVERLAY)
+static inline int spi_bus_handler_register(void)
+{
+ return 0;
+}
+#endif
+
#ifdef CONFIG_ACPI
static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
{
@@ -2270,8 +2403,14 @@ static int __init spi_init(void)
status = class_register(&spi_master_class);
if (status < 0)
goto err2;
- return 0;
+ status = spi_bus_handler_register();
+ if (status < 0)
+ goto err3;
+
+ return 0;
+err3:
+ class_unregister(&spi_master_class);
err2:
bus_unregister(&spi_bus_type);
err1:
--
1.7.12
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