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>

drivers/hsi/clients/hsi_char.c

@@ -367,7 +367,7 @@ static int hsc_rx_set(struct hsi_client *cl, struct hsc_rx_config *rxc)
 		return -EINVAL;
 	tmp = cl->rx_cfg;
 	cl->rx_cfg.mode = rxc->mode;
-	cl->rx_cfg.channels = rxc->channels;
+	cl->rx_cfg.num_hw_channels = rxc->channels;
 	cl->rx_cfg.flow = rxc->flow;
 	ret = hsi_setup(cl);
 	if (ret < 0) {
@@ -383,7 +383,7 @@ static int hsc_rx_set(struct hsi_client *cl, struct hsc_rx_config *rxc)
 static inline void hsc_rx_get(struct hsi_client *cl, struct hsc_rx_config *rxc)
 {
 	rxc->mode = cl->rx_cfg.mode;
-	rxc->channels = cl->rx_cfg.channels;
+	rxc->channels = cl->rx_cfg.num_hw_channels;
 	rxc->flow = cl->rx_cfg.flow;
 }
 
@@ -402,7 +402,7 @@ static int hsc_tx_set(struct hsi_client *cl, struct hsc_tx_config *txc)
 		return -EINVAL;
 	tmp = cl->tx_cfg;
 	cl->tx_cfg.mode = txc->mode;
-	cl->tx_cfg.channels = txc->channels;
+	cl->tx_cfg.num_hw_channels = txc->channels;
 	cl->tx_cfg.speed = txc->speed;
 	cl->tx_cfg.arb_mode = txc->arb_mode;
 	ret = hsi_setup(cl);
@@ -417,7 +417,7 @@ static int hsc_tx_set(struct hsi_client *cl, struct hsc_tx_config *txc)
 static inline void hsc_tx_get(struct hsi_client *cl, struct hsc_tx_config *txc)
 {
 	txc->mode = cl->tx_cfg.mode;
-	txc->channels = cl->tx_cfg.channels;
+	txc->channels = cl->tx_cfg.num_hw_channels;
 	txc->speed = cl->tx_cfg.speed;
 	txc->arb_mode = cl->tx_cfg.arb_mode;
 }
@@ -435,7 +435,7 @@ static ssize_t hsc_read(struct file *file, char __user *buf, size_t len,
 		return -EINVAL;
 	if (len > max_data_size)
 		len = max_data_size;
-	if (channel->ch >= channel->cl->rx_cfg.channels)
+	if (channel->ch >= channel->cl->rx_cfg.num_hw_channels)
 		return -ECHRNG;
 	if (test_and_set_bit(HSC_CH_READ, &channel->flags))
 		return -EBUSY;
@@ -492,7 +492,7 @@ static ssize_t hsc_write(struct file *file, const char __user *buf, size_t len,
 		return -EINVAL;
 	if (len > max_data_size)
 		len = max_data_size;
-	if (channel->ch >= channel->cl->tx_cfg.channels)
+	if (channel->ch >= channel->cl->tx_cfg.num_hw_channels)
 		return -ECHRNG;
 	if (test_and_set_bit(HSC_CH_WRITE, &channel->flags))
 		return -EBUSY;

drivers/hsi/hsi.c

@@ -62,18 +62,36 @@ static struct bus_type hsi_bus_type = {
 
 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 @@ int hsi_event(struct hsi_port *port, unsigned long event)
 }
 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);

include/linux/hsi/hsi.h

@@ -67,18 +67,32 @@ enum {
 	HSI_EVENT_STOP_RX,
 };
 
+/**
+ * struct hsi_channel - channel resource used by the hsi clients
+ * @id: Channel number
+ * @name: Channel name
+ */
+struct hsi_channel {
+	unsigned int	id;
+	const char	*name;
+};
+
 /**
  * struct hsi_config - Configuration for RX/TX HSI modules
  * @mode: Bit transmission mode (STREAM or FRAME)
- * @channels: Number of channels to use [1..16]
+ * @channels: Channel resources used by the client
+ * @num_channels: Number of channel resources
+ * @num_hw_channels: Number of channels the transceiver is configured for [1..16]
  * @speed: Max bit transmission speed (Kbit/s)
  * @flow: RX flow type (SYNCHRONIZED or PIPELINE)
  * @arb_mode: Arbitration mode for TX frame (Round robin, priority)
  */
 struct hsi_config {
-	unsigned int	mode;
-	unsigned int	channels;
-	unsigned int	speed;
+	unsigned int		mode;
+	struct hsi_channel	*channels;
+	unsigned int		num_channels;
+	unsigned int		num_hw_channels;
+	unsigned int		speed;
 	union {
 		unsigned int	flow;		/* RX only */
 		unsigned int	arb_mode;	/* TX only */
@@ -306,6 +320,8 @@ static inline struct hsi_port *hsi_find_port_num(struct hsi_controller *hsi,
  */
 int hsi_async(struct hsi_client *cl, struct hsi_msg *msg);
 
+int hsi_get_channel_id_by_name(struct hsi_client *cl, char *name);
+
 /**
  * hsi_id - Get HSI controller ID associated to a client
  * @cl: Pointer to a HSI client