Date:	Fri, 17 Dec 2010 12:24:37 +0100
From:	Par-Gunnar Hjalmdahl <par-gunnar.p.hjalmdahl@...ricsson.com>
To:	Pavan Savoy <pavan_savoy@...y.com>,
	Vitaly Wool <vitalywool@...il.com>,
	Alan Cox <alan@...rguk.ukuu.org.uk>,
	Arnd Bergmann <arnd@...db.de>,
	Samuel Ortiz <sameo@...ux.intel.com>,
	Marcel Holtmann <marcel@...tmann.org>
Cc:	<linux-kernel@...r.kernel.org>, <linux-bluetooth@...r.kernel.org>,
	Lukasz Rymanowski <Lukasz.Rymanowski@...to.com>,
	Linus Walleij <linus.walleij@...ricsson.com>,
	Par-Gunnar Hjalmdahl <pghatwork@...il.com>,
	Par-Gunnar Hjalmdahl <par-gunnar.p.hjalmdahl@...ricsson.com>
Subject: [PATCH 06/11] mfd: Add CG2900 test character device

This patch adds a character device used for testing the
chip driver connected to the ST-Ericsson CG2900 framework.
This patch creates a character device, which when opened registers
as a transport. This allows for test applications placed in User space
to act as chips.

Signed-off-by: Par-Gunnar Hjalmdahl <par-gunnar.p.hjalmdahl@...ricsson.com>
---
 drivers/mfd/Kconfig              |    7 +
 drivers/mfd/cg2900/Makefile      |    2 +
 drivers/mfd/cg2900/cg2900_test.c |  402 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 411 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mfd/cg2900/cg2900_test.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 44a36bb..4c2b5cc 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -299,6 +299,13 @@ config MFD_CG2900_AUDIO
 	  Does not itself connect to for example ALSA framework, but is used by
 	  ALSA drivers.
 
+config MFD_CG2900_TEST
+	tristate "Support CG2900 Test Char Device"
+	depends on MFD_CG2900
+	help
+	  Support for ST-Ericsson CG2900 Test Character Device.
+	  It is used as a virtual transport when verifying the chip driver.
+
 config PMIC_DA903X
 	bool "Dialog Semiconductor DA9030/DA9034 PMIC Support"
 	depends on I2C=y
diff --git a/drivers/mfd/cg2900/Makefile b/drivers/mfd/cg2900/Makefile
index e4f6a4b..4188888 100644
--- a/drivers/mfd/cg2900/Makefile
+++ b/drivers/mfd/cg2900/Makefile
@@ -7,6 +7,8 @@ export-objs			:= cg2900_core.o cg2900_lib.o
 
 obj-$(CONFIG_MFD_CG2900)	+= cg2900_char_devices.o
 
+obj-$(CONFIG_MFD_CG2900_TEST)	+= cg2900_test.o
+
 obj-$(CONFIG_MFD_CG2900_CHIP)	+= cg2900_chip.o
 obj-$(CONFIG_MFD_STLC2690_CHIP)	+= stlc2690_chip.o
 
diff --git a/drivers/mfd/cg2900/cg2900_test.c b/drivers/mfd/cg2900/cg2900_test.c
new file mode 100644
index 0000000..3678a29
--- /dev/null
+++ b/drivers/mfd/cg2900/cg2900_test.c
@@ -0,0 +1,402 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ * Authors:
+ * Par-Gunnar Hjalmdahl (par-gunnar.p.hjalmdahl@...ricsson.com) for ST-Ericsson.
+ * Dariusz Szymszak (dariusz.xd.szymczak@...ricsson.com) for ST-Ericsson.
+ * License terms:  GNU General Public License (GPL), version 2
+ *
+ * Driver for ST-Ericsson CG2900 test character device.
+ */
+#define NAME					"cg2900_test"
+#define pr_fmt(fmt)				NAME ": " fmt "\n"
+
+#include <asm/byteorder.h>
+#include <linux/firmware.h>
+#include <linux/fs.h>
+#include <linux/gfp.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/skbuff.h>
+#include <linux/wait.h>
+#include <linux/mfd/cg2900.h>
+
+#include "cg2900_core.h"
+
+#define MISC_DEV			(info->misc_dev.this_device)
+
+/* Device names */
+#define CG2900_CDEV_NAME		"cg2900_core_test"
+
+/**
+ * struct test_info - Main info structure for CG2900 test char device.
+ * @misc_dev:	Registered Misc Device.
+ * @rx_queue:	RX data queue.
+ * @dev:	Device structure for STE Connectivity driver.
+ * @pdev:	Platform device structure for STE Connectivity driver.
+ */
+struct test_info {
+	struct miscdevice	misc_dev;
+	struct sk_buff_head	rx_queue;
+	struct device		*dev;
+	struct platform_device	*pdev;
+};
+
+static struct test_info *test_info;
+
+/*
+ * main_wait_queue - Char device Wait Queue in CG2900 Core.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(char_wait_queue);
+
+/**
+ * tx_to_char_dev() - Handle data received from CG2900 Core.
+ * @dev:	Current chip device information.
+ * @skb:	Buffer with data coming form device.
+ */
+static int tx_to_char_dev(struct cg2900_chip_dev *dev, struct sk_buff *skb)
+{
+	struct test_info *info = dev->t_data;
+	skb_queue_tail(&info->rx_queue, skb);
+	wake_up_interruptible_all(&char_wait_queue);
+	return 0;
+}
+
+/**
+ * cg2900_test_open() - User space char device has been opened.
+ * @inode:	Device driver information.
+ * @filp:	Pointer to the file struct.
+ *
+ * Returns:
+ *   0 if there is no error.
+ *   -EACCES if transport already exists.
+ *   -ENOMEM if allocation fails.
+ *   Errors from create_work_item.
+ */
+static int cg2900_test_open(struct inode *inode, struct file *filp)
+{
+	struct test_info *info = test_info;
+	struct cg2900_chip_dev *dev;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev) {
+		dev_err(MISC_DEV, "Cannot allocate test_dev\n");
+		return -ENOMEM;
+	}
+	dev->dev = info->dev;
+	dev->pdev = info->pdev;
+	dev->t_data = info;
+	dev->t_cb.write = tx_to_char_dev;
+	filp->private_data = dev;
+
+	dev_info(MISC_DEV, "CG2900 test char dev opened\n");
+	return cg2900_register_trans_driver(dev);
+}
+
+/**
+ * cg2900_test_release() - User space char device has been closed.
+ * @inode:	Device driver information.
+ * @filp:	Pointer to the file struct.
+ *
+ * Returns:
+ *   0 if there is no error.
+ */
+static int cg2900_test_release(struct inode *inode, struct file *filp)
+{
+	struct cg2900_chip_dev *dev = filp->private_data;
+	struct test_info *info = dev->t_data;
+
+	dev_info(MISC_DEV, "CG2900 test char dev closed\n");
+	skb_queue_purge(&info->rx_queue);
+	cg2900_deregister_trans_driver(dev);
+	kfree(dev);
+
+	return 0;
+}
+
+/**
+ * cg2900_test_read() - Queue and copy buffer to user space char device.
+ * @filp:	Pointer to the file struct.
+ * @buf:	Received buffer.
+ * @count:	Count of received data in bytes.
+ * @f_pos:	Position in buffer.
+ *
+ * Returns:
+ *   >= 0 is number of bytes read.
+ *   -EFAULT if copy_to_user fails.
+ */
+static ssize_t cg2900_test_read(struct file *filp, char __user *buf,
+				size_t count, loff_t *f_pos)
+{
+	struct sk_buff *skb;
+	int bytes_to_copy;
+	int err;
+	struct cg2900_chip_dev *dev = filp->private_data;
+	struct test_info *info = dev->t_data;
+	struct sk_buff_head *rx_queue = &info->rx_queue;
+
+	dev_dbg(MISC_DEV, "cg2900_test_read count %d\n", count);
+
+	if (skb_queue_empty(rx_queue))
+		wait_event_interruptible(char_wait_queue,
+					 !(skb_queue_empty(rx_queue)));
+
+	skb = skb_dequeue(rx_queue);
+	if (!skb) {
+		dev_dbg(MISC_DEV,
+			"skb queue is empty - return with zero bytes\n");
+		bytes_to_copy = 0;
+		goto finished;
+	}
+
+	bytes_to_copy = min(count, skb->len);
+	err = copy_to_user(buf, skb->data, bytes_to_copy);
+	if (err) {
+		skb_queue_head(rx_queue, skb);
+		return -EFAULT;
+	}
+
+	skb_pull(skb, bytes_to_copy);
+
+	if (skb->len > 0)
+		skb_queue_head(rx_queue, skb);
+	else
+		kfree_skb(skb);
+
+finished:
+	return bytes_to_copy;
+}
+
+/**
+ * cg2900_test_write() - Copy buffer from user and write to CG2900 Core.
+ * @filp:	Pointer to the file struct.
+ * @buf:	Read buffer.
+ * @count:	Size of the buffer write.
+ * @f_pos:	Position in buffer.
+ *
+ * Returns:
+ *   >= 0 is number of bytes written.
+ *   -EFAULT if copy_from_user fails.
+ */
+static ssize_t cg2900_test_write(struct file *filp, const char __user *buf,
+				 size_t count, loff_t *f_pos)
+{
+	struct sk_buff *skb;
+	struct cg2900_chip_dev *dev = filp->private_data;
+	struct test_info *info = dev->t_data;
+
+	dev_dbg(MISC_DEV, "cg2900_test_write count %d\n", count);
+
+	/* Allocate the SKB and reserve space for the header */
+	skb = alloc_skb(count + RX_SKB_RESERVE, GFP_KERNEL);
+	if (!skb) {
+		dev_err(MISC_DEV, "cg2900_test_write: Failed to alloc skb\n");
+		return -ENOMEM;
+	}
+	skb_reserve(skb, RX_SKB_RESERVE);
+
+	if (copy_from_user(skb_put(skb, count), buf, count)) {
+		kfree_skb(skb);
+		return -EFAULT;
+	}
+
+	dev->c_cb.data_from_chip(dev, skb);
+
+	return count;
+}
+
+/**
+ * cg2900_test_poll() - Handle POLL call to the interface.
+ * @filp:	Pointer to the file struct.
+ * @wait:	Poll table supplied to caller.
+ *
+ * Returns:
+ *   Mask of current set POLL values (0 or (POLLIN | POLLRDNORM))
+ */
+static unsigned int cg2900_test_poll(struct file *filp, poll_table *wait)
+{
+	struct cg2900_chip_dev *dev = filp->private_data;
+	struct test_info *info = dev->t_data;
+	unsigned int mask = 0;
+
+	poll_wait(filp, &char_wait_queue, wait);
+
+	if (!(skb_queue_empty(&info->rx_queue)))
+		mask |= POLLIN | POLLRDNORM;
+
+	return mask;
+}
+
+static const struct file_operations test_char_dev_fops = {
+	.open = cg2900_test_open,
+	.release = cg2900_test_release,
+	.read = cg2900_test_read,
+	.write = cg2900_test_write,
+	.poll = cg2900_test_poll
+};
+
+/**
+ * test_char_dev_create() - Create a char device for testing.
+ * @info:	Test device info.
+ *
+ * Creates a separate char device that will interact directly with userspace
+ * test application.
+ *
+ * Returns:
+ *   0 if there is no error.
+ *   Error codes from misc_register.
+ */
+static int test_char_dev_create(struct test_info *info)
+{
+	int err;
+
+	/* Initialize the RX queue */
+	skb_queue_head_init(&info->rx_queue);
+
+	/* Prepare miscdevice struct before registering the device */
+	info->misc_dev.minor = MISC_DYNAMIC_MINOR;
+	info->misc_dev.name = CG2900_CDEV_NAME;
+	info->misc_dev.fops = &test_char_dev_fops;
+	info->misc_dev.parent = info->dev;
+	info->misc_dev.mode = S_IRUGO | S_IWUGO;
+
+	err = misc_register(&info->misc_dev);
+	if (err) {
+		dev_err(info->dev, "Error %d registering misc dev", err);
+		return err;
+	}
+
+	return 0;
+}
+
+/**
+ * test_char_dev_destroy() - Clean up after test_char_dev_create().
+ * @info:	Test device info.
+ */
+static void test_char_dev_destroy(struct test_info *info)
+{
+	int err;
+
+	err = misc_deregister(&info->misc_dev);
+	if (err)
+		dev_err(info->dev, "Error %d deregistering misc dev\n", err);
+
+	/* Clean the message queue */
+	skb_queue_purge(&info->rx_queue);
+}
+
+/**
+ * cg2900_test_probe() - Initialize module.
+ *
+ * @pdev:	Platform device.
+ *
+ * This function initializes and registers the test misc char device.
+ *
+ * Returns:
+ *   0 if success.
+ *   -ENOMEM for failed alloc or structure creation.
+ *   -EEXIST if device already exists.
+ *   Error codes generated by test_char_dev_create.
+ */
+static int __devinit cg2900_test_probe(struct platform_device *pdev)
+{
+	int err;
+
+	dev_dbg(&pdev->dev, "cg2900_test_probe\n");
+
+	if (test_info) {
+		dev_err(&pdev->dev, "test_info exists\n");
+		return -EEXIST;
+	}
+
+	test_info = kzalloc(sizeof(*test_info), GFP_KERNEL);
+	if (!test_info) {
+		dev_err(&pdev->dev, "Couldn't allocate test_info\n");
+		return -ENOMEM;
+	}
+
+	test_info->dev = &pdev->dev;
+	test_info->pdev = pdev;
+
+	/* Create and add test char device. */
+	err = test_char_dev_create(test_info);
+	if (err) {
+		kfree(test_info);
+		test_info = NULL;
+		return err;
+	}
+
+	dev_set_drvdata(&pdev->dev, test_info);
+
+	dev_info(&pdev->dev, "CG2900 test char device driver started\n");
+
+	return 0;
+}
+
+/**
+ * cg2900_test_remove() - Remove module.
+ *
+ * @pdev:	Platform device.
+ *
+ * Returns:
+ *   0 if success.
+ *   -ENOMEM if core_info does not exist.
+ *   -EINVAL if platform data does not exist in the device.
+ */
+static int __devexit cg2900_test_remove(struct platform_device *pdev)
+{
+	struct test_info *test_info;
+
+	dev_dbg(&pdev->dev, "cg2900_test_remove\n");
+	test_info = dev_get_drvdata(&pdev->dev);
+	test_char_dev_destroy(test_info);
+	dev_set_drvdata(&pdev->dev, NULL);
+	kfree(test_info);
+	test_info = NULL;
+	dev_info(&pdev->dev, "CG2900 Test char device driver removed\n");
+	return 0;
+}
+
+static struct platform_driver cg2900_test_driver = {
+	.driver = {
+		.name	= "cg2900-test",
+		.owner	= THIS_MODULE,
+	},
+	.probe	= cg2900_test_probe,
+	.remove	= __devexit_p(cg2900_test_remove),
+};
+
+/**
+ * cg2900_test_init() - Initialize module.
+ *
+ * Registers platform driver.
+ */
+static int __init cg2900_test_init(void)
+{
+	pr_debug("cg2900_test_init");
+	return platform_driver_register(&cg2900_test_driver);
+}
+
+/**
+ * cg2900_test_exit() - Remove module.
+ *
+ * Unregisters platform driver.
+ */
+static void __exit cg2900_test_exit(void)
+{
+	pr_debug("cg2900_test_exit");
+	platform_driver_unregister(&cg2900_test_driver);
+}
+
+module_init(cg2900_test_init);
+module_exit(cg2900_test_exit);
+
+MODULE_AUTHOR("Par-Gunnar Hjalmdahl ST-Ericsson");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Linux CG2900 Test Char Device Driver");
-- 
1.7.3.2

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