spmi: Add del_controller functionality

The del_controller function is required to release any client device
resources as well as the debugfs entries.  This patch adds that
functionality.

Change-Id: I91c6b840acfe002f096570cbe1867b302c475e60
Signed-off-by: Kenneth Heitke <kheitke@codeaurora.org>

drivers/spmi/spmi-dbgfs.c

@@ -1,4 +1,4 @@
-/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -24,7 +24,6 @@
  *        /spmi-#
  */
 
-#define DEBUG
 #define pr_fmt(fmt) "%s:%d: " fmt, __func__, __LINE__
 
 #include <linux/kernel.h>
@@ -582,7 +581,7 @@ static struct dentry *spmi_dfs_create_fs(void)
 {
 	struct dentry *root, *file;
 
-	pr_debug("Creating SPMI debugfs file-system at\n");
+	pr_debug("Creating SPMI debugfs file-system\n");
 	root = debugfs_create_dir(DFS_ROOT_NAME, NULL);
 	if (IS_ERR(root)) {
 		pr_err("Error creating top level directory err:%ld",
@@ -696,6 +695,41 @@ err_create_dir_failed:
 	return -ENOMEM;
 }
 
+/*
+ * spmi_dfs_del_controller: deletes spmi controller entry
+ * @return zero on success
+ */
+int spmi_dfs_del_controller(struct spmi_controller *ctrl)
+{
+	int rc;
+	struct list_head *pos, *tmp;
+	struct spmi_ctrl_data *ctrl_data;
+
+	pr_debug("Deleting controller %s\n", ctrl->dev.kobj.name);
+
+	rc = mutex_lock_interruptible(&dbgfs_data.lock);
+	if (rc)
+		return rc;
+
+	list_for_each_safe(pos, tmp, &dbgfs_data.ctrl) {
+		ctrl_data = list_entry(pos, struct spmi_ctrl_data, node);
+
+		if (ctrl_data->ctrl == ctrl) {
+			debugfs_remove_recursive(ctrl_data->dir);
+			list_del(pos);
+			kfree(ctrl_data);
+			rc = 0;
+			goto done;
+		}
+	}
+	rc = -EINVAL;
+	pr_debug("Unknown controller %s\n", ctrl->dev.kobj.name);
+
+done:
+	mutex_unlock(&dbgfs_data.lock);
+	return rc;
+}
+
 /*
  * spmi_dfs_create_file: creates a new file in the SPMI debugfs
  * @returns valid dentry pointer on success or NULL

drivers/spmi/spmi-dbgfs.h

@@ -1,4 +1,4 @@
-/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -16,8 +16,10 @@
 
 #ifdef CONFIG_DEBUG_FS
 int spmi_dfs_add_controller(struct spmi_controller *ctrl);
+int spmi_dfs_del_controller(struct spmi_controller *ctrl);
 #else
 static int spmi_dfs_add_controller(struct spmi_controller *ctrl) { return 0; }
+static int spmi_dfs_del_controller(struct spmi_controller *ctrl) { return 0; }
 #endif
 
 struct dentry *spmi_dfs_create_file(struct spmi_controller *ctrl,

drivers/spmi/spmi.c

@@ -32,9 +32,8 @@ struct spmii_boardinfo {
 static DEFINE_MUTEX(board_lock);
 static LIST_HEAD(board_list);
 static DEFINE_IDR(ctrl_idr);
-static struct device_type spmi_ctrl_type = { 0 };
-
-#define to_spmi(dev)	platform_get_drvdata(to_platform_device(dev))
+static struct device_type spmi_dev_type;
+static struct device_type spmi_ctrl_type;
 
 /* Forward declarations */
 struct bus_type spmi_bus_type;
@@ -69,6 +68,9 @@ int spmi_add_controller(struct spmi_controller *ctrl)
 	int	id;
 	int	status;
 
+	if (!ctrl)
+		return -EINVAL;
+
 	pr_debug("adding controller for bus %d (0x%p)\n", ctrl->nr, ctrl);
 
 	if (ctrl->nr & ~MAX_ID_MASK) {
@@ -98,18 +100,70 @@ retry:
 }
 EXPORT_SYMBOL_GPL(spmi_add_controller);
 
+/* Remove a device associated with a controller */
+static int spmi_ctrl_remove_device(struct device *dev, void *data)
+{
+	struct spmi_device *spmidev = to_spmi_device(dev);
+	struct spmi_controller *ctrl = data;
+
+	if (dev->type == &spmi_dev_type && spmidev->ctrl == ctrl)
+		spmi_remove_device(spmidev);
+
+	return 0;
+}
+
 /**
  * spmi_del_controller: Controller tear-down.
- * @ctrl: controller to which this device is to be added to.
+ * @ctrl: controller to be removed.
  *
  * Controller added with the above API is torn down using this API.
  */
 int spmi_del_controller(struct spmi_controller *ctrl)
 {
-	return -ENXIO;
+	struct spmi_controller *found;
+
+	if (!ctrl)
+		return -EINVAL;
+
+	/* Check that the ctrl has been added */
+	mutex_lock(&board_lock);
+	found = idr_find(&ctrl_idr, ctrl->nr);
+	mutex_unlock(&board_lock);
+	if (found != ctrl)
+		return -EINVAL;
+
+	/* Remove all the clients associated with this controller */
+	mutex_lock(&board_lock);
+	bus_for_each_dev(&spmi_bus_type, NULL, ctrl, spmi_ctrl_remove_device);
+	mutex_unlock(&board_lock);
+
+	spmi_dfs_del_controller(ctrl);
+
+	mutex_lock(&board_lock);
+	idr_remove(&ctrl_idr, ctrl->nr);
+	mutex_unlock(&board_lock);
+
+	init_completion(&ctrl->dev_released);
+	device_unregister(&ctrl->dev);
+	wait_for_completion(&ctrl->dev_released);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(spmi_del_controller);
 
+#define spmi_ctrl_attr_gr NULL
+static void spmi_ctrl_release(struct device *dev)
+{
+	struct spmi_controller *ctrl = to_spmi_controller(dev);
+
+	complete(&ctrl->dev_released);
+}
+
+static struct device_type spmi_ctrl_type = {
+	.groups		= spmi_ctrl_attr_gr,
+	.release	= spmi_ctrl_release,
+};
+
 #define spmi_device_attr_gr NULL
 #define spmi_device_uevent NULL
 static void spmi_dev_release(struct device *dev)
@@ -141,7 +195,7 @@ struct spmi_device *spmi_alloc_device(struct spmi_controller *ctrl)
 {
 	struct spmi_device *spmidev;
 
-	if (!ctrl) {
+	if (!ctrl || !spmi_busnum_to_ctrl(ctrl->nr)) {
 		pr_err("Missing SPMI controller\n");
 		return NULL;
 	}
@@ -174,12 +228,15 @@ static struct device *get_valid_device(struct spmi_device *spmidev)
 	if (dev->bus != &spmi_bus_type || dev->type != &spmi_dev_type)
 		return NULL;
 
+	if (!spmidev->ctrl || !spmi_busnum_to_ctrl(spmidev->ctrl->nr))
+		return NULL;
+
 	return dev;
 }
 
 /**
  * spmi_add_device: Add a new device without register board info.
- * @ctrl: controller to which this device is to be added to.
+ * @spmi_dev: spmi_device to be added (registered).
  *
  * Called when device doesn't have an explicit client-driver to be probed, or
  * the client-driver is a module installed dynamically.
@@ -190,7 +247,7 @@ int spmi_add_device(struct spmi_device *spmidev)
 	struct device *dev = get_valid_device(spmidev);
 
 	if (!dev) {
-		pr_err("%s: invalid SPMI device\n", __func__);
+		pr_err("invalid SPMI device\n");
 		return -EINVAL;
 	}
 

include/linux/spmi.h

@@ -54,6 +54,7 @@ struct spmi_device;
 struct spmi_controller {
 	struct device		dev;
 	unsigned int		nr;
+	struct completion	dev_released;
 	int		(*cmd)(struct spmi_controller *, u8 opcode, u8 sid);
 	int		(*read_cmd)(struct spmi_controller *,
 				u8 opcode, u8 sid, u16 addr, u8 bc, u8 *buf);