[PATCH V2 2/6] of/slimbus: OF helper for SLIMbus

[Sagar Dharia <sdharia@codeaurora.org>]

OF helper routine scans the SLIMbus DeviceTree, allocates resources,
and creates slim_devices according to the hierarchy.

Signed-off-by: Sagar Dharia <sdharia@codeaurora.org>
---
 Documentation/devicetree/bindings/slimbus/bus.txt | 34 ++++++++++
 drivers/slimbus/slimbus.c                         | 76 +++++++++++++++++++++++
 2 files changed, 110 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/slimbus/bus.txt

diff --git a/Documentation/devicetree/bindings/slimbus/bus.txt b/Documentation/devicetree/bindings/slimbus/bus.txt
new file mode 100644
index 0000000..a7a36aa
--- /dev/null
+++ b/Documentation/devicetree/bindings/slimbus/bus.txt
@@ -0,0 +1,34 @@
+SLIM(Serial Low Power Interchip Media Bus) bus
+
+SLIMbus is a 2-wire bus, and is used to communicate with peripheral
+components like audio-codec.
+
+Required property for SLIMbus controller node:
+- compatible	- name of SLIMbus controller.
+
+No other properties are required in the SLIMbus controller bus node.
+
+Child nodes:
+
+Every SLIMbus controller node can contain zero or more child nodes
+representing slave devices on the bus. Every SLIMbus slave device is
+uniquely determined by the 6 byte enumeration address.
+
+Required property for SLIMbus child node:
+enumeration-addr	- 6 byte enumeration address of the slave
+
+SLIMbus example for Qualcomm's slimbus manager compoent:
+
+	slim@28080000 {
+		compatible = "qcom,slim-msm";
+		reg = <0x28080000 0x2000>,
+		reg-names = "slimbus_physical";
+		interrupts = <0 33 0>;
+		interrupt-names = "slimbus_irq";
+		clocks = <&lcc SLIMBUS_SRC>, <&lcc AUDIO_SLIMBUS_CLK>;
+		clock-names = "iface_clk", "core_clk";
+
+		slim_codec_slave {
+			enumeration-addr = [00 01 60 00 17 02];
+		};
+	};
diff --git a/drivers/slimbus/slimbus.c b/drivers/slimbus/slimbus.c
index 2baf43a..0295a06 100644
--- a/drivers/slimbus/slimbus.c
+++ b/drivers/slimbus/slimbus.c
@@ -19,6 +19,7 @@
 #include <linux/idr.h>
 #include <linux/pm_runtime.h>
 #include <linux/slimbus.h>
+#include <linux/of.h>
 
 static DEFINE_MUTEX(slim_lock);
 static DEFINE_IDR(ctrl_idr);
@@ -270,6 +271,80 @@ static LIST_HEAD(board_list);
 static LIST_HEAD(slim_ctrl_list);
 static DEFINE_MUTEX(board_lock);
 
+#if IS_ENABLED(CONFIG_OF)
+/* OF helpers for SLIMbus */
+static void of_register_slim_devices(struct slim_controller *ctrl)
+{
+	struct device_node *node;
+	struct slim_boardinfo *temp, *binfo = NULL;
+	int ret, n = 0;
+
+	if (!ctrl->dev.of_node)
+		return;
+
+	for_each_child_of_node(ctrl->dev.of_node, node) {
+		struct property *prop;
+		u8 *ea;
+		struct slim_device *slim;
+		char *name;
+
+		prop = of_find_property(node, "enumeration-addr", NULL);
+		if (!prop || prop->length != 6) {
+			dev_err(&ctrl->dev, "of_slim: invalid E-addr\n");
+			continue;
+		}
+		ea = (u8 *)prop->value;
+		name = kcalloc(SLIMBUS_NAME_SIZE, sizeof(char), GFP_KERNEL);
+		if (!name)
+			goto of_slim_err;
+
+		ret = of_modalias_node(node, name, SLIMBUS_NAME_SIZE);
+		if (ret < 0) {
+			dev_err(&ctrl->dev, "of_slim: modalias fail:%d on %s\n",
+				ret, node->full_name);
+			kfree(name);
+			continue;
+		}
+		slim = kzalloc(sizeof(struct slim_device), GFP_KERNEL);
+		if (!slim) {
+			kfree(name);
+			goto of_slim_err;
+		}
+		slim->e_addr.manf_id = (u16)(ea[5] << 8) | ea[4];
+		slim->e_addr.prod_code = (u16)(ea[3] << 8) | ea[2];
+		slim->e_addr.dev_index = ea[1];
+		slim->e_addr.instance = ea[0];
+
+
+		temp = krealloc(binfo, (n + 1) * sizeof(struct slim_boardinfo),
+					GFP_KERNEL);
+		if (!temp) {
+			kfree(name);
+			kfree(slim);
+			goto of_slim_err;
+		}
+		binfo = temp;
+		slim->dev.of_node = of_node_get(node);
+		slim->name = name;
+		binfo[n].bus_num = ctrl->nr;
+		binfo[n].slim_slave = slim;
+		n++;
+	}
+	slim_register_board_info(binfo, n);
+	return;
+
+of_slim_err:
+	n--;
+	while (n >= 0) {
+		kfree(binfo[n].slim_slave->name);
+		kfree(binfo[n].slim_slave);
+	}
+	kfree(binfo);
+}
+#else
+static void of_register_slim_devices(struct slim_controller *ctrl) { }
+#endif
+
 /* If controller is not present, only add to boards list */
 static void slim_match_ctrl_to_boardinfo(struct slim_controller *ctrl,
 					 struct slim_boardinfo *bi)
@@ -326,6 +401,7 @@ void slim_ctrl_add_boarddevs(struct slim_controller *ctrl)
 {
 	struct sbi_boardinfo *bi;
 
+	of_register_slim_devices(ctrl);
 	mutex_lock(&board_lock);
 	list_add_tail(&ctrl->list, &slim_ctrl_list);
 	list_for_each_entry(bi, &board_list, list)
-- 
1.8.2.1