HSI: Add common DT binding for HSI client devices
Implement and document generic DT bindings for HSI clients.
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
Tested-By: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
diff --git a/Documentation/devicetree/bindings/hsi/client-devices.txt b/Documentation/devicetree/bindings/hsi/client-devices.txt
new file mode 100644
index 0000000..104c9a3
--- /dev/null
+++ b/Documentation/devicetree/bindings/hsi/client-devices.txt
@@ -0,0 +1,44 @@
+Each HSI port is supposed to have one child node, which
+symbols the remote device connected to the HSI port. The
+following properties are standardized for HSI clients:
+
+Required HSI configuration properties:
+
+- hsi-channel-ids: A list of channel ids
+
+- hsi-rx-mode: Receiver Bit transmission mode ("stream" or "frame")
+- hsi-tx-mode: Transmitter Bit transmission mode ("stream" or "frame")
+- hsi-mode: May be used instead hsi-rx-mode and hsi-tx-mode if
+ the transmission mode is the same for receiver and
+ transmitter
+- hsi-speed-kbps: Max bit transmission speed in kbit/s
+- hsi-flow: RX flow type ("synchronized" or "pipeline")
+- hsi-arb-mode: Arbitration mode for TX frame ("round-robin", "priority")
+
+Optional HSI configuration properties:
+
+- hsi-channel-names: A list with one name per channel specified in the
+ hsi-channel-ids property
+
+
+Device Tree node example for an HSI client:
+
+hsi-controller {
+ hsi-port {
+ modem: hsi-client {
+ compatible = "nokia,n900-modem";
+
+ hsi-channel-ids = <0>, <1>, <2>, <3>;
+ hsi-channel-names = "mcsaab-control",
+ "speech-control",
+ "speech-data",
+ "mcsaab-data";
+ hsi-speed-kbps = <55000>;
+ hsi-mode = "frame";
+ hsi-flow = "synchronized";
+ hsi-arb-mode = "round-robin";
+
+ /* more client specific properties */
+ };
+ };
+};
diff --git a/drivers/hsi/hsi.c b/drivers/hsi/hsi.c
index 834a2d6..fe93712 100644
--- a/drivers/hsi/hsi.c
+++ b/drivers/hsi/hsi.c
@@ -26,6 +26,8 @@
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
#include "hsi_core.h"
static ssize_t modalias_show(struct device *dev,
@@ -50,7 +52,13 @@
static int hsi_bus_match(struct device *dev, struct device_driver *driver)
{
- return strcmp(dev_name(dev), driver->name) == 0;
+ if (of_driver_match_device(dev, driver))
+ return true;
+
+ if (strcmp(dev_name(dev), driver->name) == 0)
+ return true;
+
+ return false;
}
static struct bus_type hsi_bus_type = {
@@ -123,6 +131,202 @@
}
}
+#ifdef CONFIG_OF
+static struct hsi_board_info hsi_char_dev_info = {
+ .name = "hsi_char",
+};
+
+static int hsi_of_property_parse_mode(struct device_node *client, char *name,
+ unsigned int *result)
+{
+ const char *mode;
+ int err;
+
+ err = of_property_read_string(client, name, &mode);
+ if (err < 0)
+ return err;
+
+ if (strcmp(mode, "stream") == 0)
+ *result = HSI_MODE_STREAM;
+ else if (strcmp(mode, "frame") == 0)
+ *result = HSI_MODE_FRAME;
+ else
+ return -EINVAL;
+
+ return 0;
+}
+
+static int hsi_of_property_parse_flow(struct device_node *client, char *name,
+ unsigned int *result)
+{
+ const char *flow;
+ int err;
+
+ err = of_property_read_string(client, name, &flow);
+ if (err < 0)
+ return err;
+
+ if (strcmp(flow, "synchronized") == 0)
+ *result = HSI_FLOW_SYNC;
+ else if (strcmp(flow, "pipeline") == 0)
+ *result = HSI_FLOW_PIPE;
+ else
+ return -EINVAL;
+
+ return 0;
+}
+
+static int hsi_of_property_parse_arb_mode(struct device_node *client,
+ char *name, unsigned int *result)
+{
+ const char *arb_mode;
+ int err;
+
+ err = of_property_read_string(client, name, &arb_mode);
+ if (err < 0)
+ return err;
+
+ if (strcmp(arb_mode, "round-robin") == 0)
+ *result = HSI_ARB_RR;
+ else if (strcmp(arb_mode, "priority") == 0)
+ *result = HSI_ARB_PRIO;
+ else
+ return -EINVAL;
+
+ return 0;
+}
+
+static void hsi_add_client_from_dt(struct hsi_port *port,
+ struct device_node *client)
+{
+ struct hsi_client *cl;
+ struct hsi_channel channel;
+ struct property *prop;
+ char name[32];
+ int length, cells, err, i, max_chan, mode;
+
+ cl = kzalloc(sizeof(*cl), GFP_KERNEL);
+ if (!cl)
+ return;
+
+ err = of_modalias_node(client, name, sizeof(name));
+ if (err)
+ goto err;
+
+ dev_set_name(&cl->device, "%s", name);
+
+ err = hsi_of_property_parse_mode(client, "hsi-mode", &mode);
+ if (err) {
+ err = hsi_of_property_parse_mode(client, "hsi-rx-mode",
+ &cl->rx_cfg.mode);
+ if (err)
+ goto err;
+
+ err = hsi_of_property_parse_mode(client, "hsi-tx-mode",
+ &cl->tx_cfg.mode);
+ if (err)
+ goto err;
+ } else {
+ cl->rx_cfg.mode = mode;
+ cl->tx_cfg.mode = mode;
+ }
+
+ err = of_property_read_u32(client, "hsi-speed-kbps",
+ &cl->tx_cfg.speed);
+ if (err)
+ goto err;
+ cl->rx_cfg.speed = cl->tx_cfg.speed;
+
+ err = hsi_of_property_parse_flow(client, "hsi-flow",
+ &cl->rx_cfg.flow);
+ if (err)
+ goto err;
+
+ err = hsi_of_property_parse_arb_mode(client, "hsi-arb-mode",
+ &cl->rx_cfg.arb_mode);
+ if (err)
+ goto err;
+
+ prop = of_find_property(client, "hsi-channel-ids", &length);
+ if (!prop) {
+ err = -EINVAL;
+ goto err;
+ }
+
+ cells = length / sizeof(u32);
+
+ cl->rx_cfg.num_channels = cells;
+ cl->tx_cfg.num_channels = cells;
+
+ cl->rx_cfg.channels = kzalloc(cells * sizeof(channel), GFP_KERNEL);
+ if (!cl->rx_cfg.channels) {
+ err = -ENOMEM;
+ goto err;
+ }
+
+ cl->tx_cfg.channels = kzalloc(cells * sizeof(channel), GFP_KERNEL);
+ if (!cl->tx_cfg.channels) {
+ err = -ENOMEM;
+ goto err2;
+ }
+
+ max_chan = 0;
+ for (i = 0; i < cells; i++) {
+ err = of_property_read_u32_index(client, "hsi-channel-ids", i,
+ &channel.id);
+ if (err)
+ goto err3;
+
+ err = of_property_read_string_index(client, "hsi-channel-names",
+ i, &channel.name);
+ if (err)
+ channel.name = NULL;
+
+ if (channel.id > max_chan)
+ max_chan = channel.id;
+
+ cl->rx_cfg.channels[i] = channel;
+ cl->tx_cfg.channels[i] = channel;
+ }
+
+ cl->rx_cfg.num_hw_channels = max_chan + 1;
+ cl->tx_cfg.num_hw_channels = max_chan + 1;
+
+ cl->device.bus = &hsi_bus_type;
+ cl->device.parent = &port->device;
+ cl->device.release = hsi_client_release;
+ cl->device.of_node = client;
+
+ if (device_register(&cl->device) < 0) {
+ pr_err("hsi: failed to register client: %s\n", name);
+ put_device(&cl->device);
+ goto err3;
+ }
+
+ return;
+
+err3:
+ kfree(cl->tx_cfg.channels);
+err2:
+ kfree(cl->rx_cfg.channels);
+err:
+ kfree(cl);
+ pr_err("hsi client: missing or incorrect of property: err=%d\n", err);
+}
+
+void hsi_add_clients_from_dt(struct hsi_port *port, struct device_node *clients)
+{
+ struct device_node *child;
+
+ /* register hsi-char device */
+ hsi_new_client(port, &hsi_char_dev_info);
+
+ for_each_available_child_of_node(clients, child)
+ hsi_add_client_from_dt(port, child);
+}
+EXPORT_SYMBOL_GPL(hsi_add_clients_from_dt);
+#endif
+
int hsi_remove_client(struct device *dev, void *data __maybe_unused)
{
device_unregister(dev);
@@ -505,7 +709,7 @@
EXPORT_SYMBOL_GPL(hsi_unregister_port_event);
/**
- * hsi_event -Notifies clients about port events
+ * hsi_event - Notifies clients about port events
* @port: Port where the event occurred
* @event: The event type
*
diff --git a/include/linux/hsi/hsi.h b/include/linux/hsi/hsi.h
index e20a399..3ec0630 100644
--- a/include/linux/hsi/hsi.h
+++ b/include/linux/hsi/hsi.h
@@ -301,6 +301,17 @@
int hsi_remove_client(struct device *dev, void *data);
void hsi_port_unregister_clients(struct hsi_port *port);
+#ifdef CONFIG_OF
+void hsi_add_clients_from_dt(struct hsi_port *port,
+ struct device_node *clients);
+#else
+static inline void hsi_add_clients_from_dt(struct hsi_port *port,
+ struct device_node *clients)
+{
+ return;
+}
+#endif
+
static inline void hsi_controller_set_drvdata(struct hsi_controller *hsi,
void *data)
{
