HSI: Add channel resource support to HSI clients

Make HSI channel ids platform data, which can be provided
by platform data.

Signed-off-by: Sebastian Reichel <sre@kernel.org>
Tested-By: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
diff --git a/drivers/hsi/hsi.c b/drivers/hsi/hsi.c
index e96a987..de2ad8f 100644
--- a/drivers/hsi/hsi.c
+++ b/drivers/hsi/hsi.c
@@ -62,18 +62,36 @@
 
 static void hsi_client_release(struct device *dev)
 {
-	kfree(to_hsi_client(dev));
+	struct hsi_client *cl = to_hsi_client(dev);
+
+	kfree(cl->tx_cfg.channels);
+	kfree(cl->rx_cfg.channels);
+	kfree(cl);
 }
 
 static void hsi_new_client(struct hsi_port *port, struct hsi_board_info *info)
 {
 	struct hsi_client *cl;
+	size_t size;
 
 	cl = kzalloc(sizeof(*cl), GFP_KERNEL);
 	if (!cl)
 		return;
+
 	cl->tx_cfg = info->tx_cfg;
+	if (cl->tx_cfg.channels) {
+		size = cl->tx_cfg.num_channels * sizeof(*cl->tx_cfg.channels);
+		cl->tx_cfg.channels = kzalloc(size , GFP_KERNEL);
+		memcpy(cl->tx_cfg.channels, info->tx_cfg.channels, size);
+	}
+
 	cl->rx_cfg = info->rx_cfg;
+	if (cl->rx_cfg.channels) {
+		size = cl->rx_cfg.num_channels * sizeof(*cl->rx_cfg.channels);
+		cl->rx_cfg.channels = kzalloc(size , GFP_KERNEL);
+		memcpy(cl->rx_cfg.channels, info->rx_cfg.channels, size);
+	}
+
 	cl->device.bus = &hsi_bus_type;
 	cl->device.parent = &port->device;
 	cl->device.release = hsi_client_release;
@@ -502,6 +520,32 @@
 }
 EXPORT_SYMBOL_GPL(hsi_event);
 
+/**
+ * hsi_get_channel_id_by_name - acquire channel id by channel name
+ * @cl: HSI client, which uses the channel
+ * @name: name the channel is known under
+ *
+ * Clients can call this function to get the hsi channel ids similar to
+ * requesting IRQs or GPIOs by name. This function assumes the same
+ * channel configuration is used for RX and TX.
+ *
+ * Returns -errno on error or channel id on success.
+ */
+int hsi_get_channel_id_by_name(struct hsi_client *cl, char *name)
+{
+	int i;
+
+	if (!cl->rx_cfg.channels)
+		return -ENOENT;
+
+	for (i = 0; i < cl->rx_cfg.num_channels; i++)
+		if (!strcmp(cl->rx_cfg.channels[i].name, name))
+			return cl->rx_cfg.channels[i].id;
+
+	return -ENXIO;
+}
+EXPORT_SYMBOL_GPL(hsi_get_channel_id_by_name);
+
 static int __init hsi_init(void)
 {
 	return bus_register(&hsi_bus_type);