CMT: Introduces the Nokia CMT driver.

Add the Nokia CMT driver. The CMT driver takes care of the
APE-CMT hardware outside the SSI/HSI communication.

The initial implementation introduces a CMT reset notification
interface for protocols drivers like cmt_speech and ssi_protocol.

Signed-off-by: Carlos Chinea <carlos.chinea@nokia.com>
Signed-off-by: Kai Vehmanen <kai.vehmanen@nokia.com>
Signed-off-by: Joni Lapilainen <joni.lapilainen@gmail.com>

4 files changed, 289 insertions, 0 deletions

diff --git a/drivers/misc/cmt/Kconfig b/drivers/misc/cmt/Kconfig
new file mode 100644
index 000000000000..a339d79c1709
--- /dev/null
+++ b/drivers/misc/cmt/Kconfig
@@ -0,0 +1,9 @@
+#
+# CMT
+#
+config CMT
+	tristate "Enable CMT support"
+	---help---
+	  If you say Y here, you will enable CMT support.
+
+	  If unsure, say Y, or else you will not be able to use the CMT.
diff --git a/drivers/misc/cmt/Makefile b/drivers/misc/cmt/Makefile
new file mode 100644
index 000000000000..b38816aa61f4
--- /dev/null
+++ b/drivers/misc/cmt/Makefile
@@ -0,0 +1,4 @@
+#
+# Makefile for CMT module
+#
+obj-$(CONFIG_CMT)	+= cmt.o
diff --git a/drivers/misc/cmt/cmt.c b/drivers/misc/cmt/cmt.c
new file mode 100644
index 000000000000..9efcd9b595c4
--- /dev/null
+++ b/drivers/misc/cmt/cmt.c
@@ -0,0 +1,223 @@
+/*
+ * cmt.c
+ *
+ * CMT support.
+ *
+ * Copyright (C) 2009 Nokia Corporation. All rights reserved.
+ *
+ * Contact: Carlos Chinea <carlos.chinea@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <asm/atomic.h>
+#include <linux/cmt.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+/**
+ * struct cmt_device - CMT device data
+ * @cmt_rst_ind_tasklet: Bottom half for CMT reset line events
+ * @cmt_rst_ind_gpio: GPIO number of the CMT reset line
+ * @n_head: List of notifiers registered to get CMT events
+ * @node: Link on the list of available CMTs
+ * @device: Reference to the CMT platform device
+ */
+struct cmt_device {
+	struct tasklet_struct		cmt_rst_ind_tasklet;
+	unsigned int			cmt_rst_ind_gpio;
+	struct atomic_notifier_head	n_head;
+	struct list_head		node;
+	struct device			*device;
+};
+
+static LIST_HEAD(cmt_list);	/* List of CMT devices */
+
+int cmt_notifier_register(struct cmt_device *cmtdev, struct notifier_block *nb)
+{
+	struct cmt_device *cmt;
+	int err = -ENODEV;
+
+	if ((!cmtdev) || (!nb))
+		return -EINVAL;
+
+	list_for_each_entry(cmt, &cmt_list, node)
+		if (cmt == cmtdev) {
+			err = atomic_notifier_chain_register(&cmt->n_head, nb);
+			break;
+		}
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(cmt_notifier_register);
+
+int cmt_notifier_unregister(struct cmt_device *cmtdev,
+						struct notifier_block *nb)
+{
+	struct cmt_device *cmt;
+	int err = -ENODEV;
+
+	if ((!cmtdev) || (!nb))
+		return -EINVAL;
+
+	list_for_each_entry(cmt, &cmt_list, node)
+		if (cmt == cmtdev) {
+			err = atomic_notifier_chain_unregister(&cmt->n_head,
+									nb);
+			break;
+		}
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(cmt_notifier_unregister);
+
+struct cmt_device *cmt_get(const char *name)
+{
+	struct cmt_device *p, *cmt = ERR_PTR(-ENODEV);
+
+	list_for_each_entry(p, &cmt_list, node)
+		if (strcmp(name, dev_name(p->device)) == 0) {
+			cmt = p;
+			break;
+		}
+
+	return cmt;
+}
+EXPORT_SYMBOL_GPL(cmt_get);
+
+void cmt_put(struct cmt_device *cmtdev)
+{
+}
+EXPORT_SYMBOL_GPL(cmt_put);
+
+static void do_cmt_rst_ind_tasklet(unsigned long cmtdev)
+{
+	struct cmt_device *cmt = (struct cmt_device *)cmtdev;
+
+	dev_dbg(cmt->device, "*** CMT rst line change detected (%d) ***\n",
+					gpio_get_value(cmt->cmt_rst_ind_gpio));
+	atomic_notifier_call_chain(&cmt->n_head, CMT_RESET, NULL);
+}
+
+static irqreturn_t cmt_rst_ind_isr(int irq, void *cmtdev)
+{
+	struct cmt_device *cmt = (struct cmt_device *)cmtdev;
+
+	tasklet_schedule(&cmt->cmt_rst_ind_tasklet);
+
+	return IRQ_HANDLED;
+}
+
+static int __init cmt_probe(struct platform_device *pd)
+{
+	struct cmt_platform_data *pdata = pd->dev.platform_data;
+	struct cmt_device *cmt;
+	int irq;
+	int err;
+
+	if (!pdata) {
+		pr_err("CMT: No platform_data found on cmt device\n");
+		return -ENXIO;
+	}
+	cmt = kzalloc(sizeof(*cmt), GFP_KERNEL);
+	if (!cmt) {
+		dev_err(&pd->dev, "Could not allocate memory for cmtdev\n");
+		return -ENOMEM;
+	}
+
+	cmt->device = &pd->dev;
+	cmt->cmt_rst_ind_gpio = pdata->cmt_rst_ind_gpio;
+	err = gpio_request(cmt->cmt_rst_ind_gpio, "cmt_rst_ind");
+	if (err < 0) {
+		dev_err(&pd->dev, "Request cmt_rst_ind gpio%d failed\n",
+							cmt->cmt_rst_ind_gpio);
+		goto rback1;
+	}
+	gpio_direction_input(cmt->cmt_rst_ind_gpio);
+	tasklet_init(&cmt->cmt_rst_ind_tasklet, do_cmt_rst_ind_tasklet,
+							(unsigned long)cmt);
+	irq = gpio_to_irq(cmt->cmt_rst_ind_gpio);
+	err = request_irq(irq, cmt_rst_ind_isr,
+		IRQF_DISABLED | IRQF_TRIGGER_RISING, "cmt_rst_ind", cmt);
+	if (err < 0) {
+		dev_err(&pd->dev, "Request cmt_rst_ind irq(%d) failed\n", irq);
+		goto rback2;
+	}
+	enable_irq_wake(irq);
+	ATOMIC_INIT_NOTIFIER_HEAD(&cmt->n_head);
+	list_add(&cmt->node, &cmt_list);
+	platform_set_drvdata(pd, cmt);
+
+	return 0;
+rback2:
+	gpio_free(cmt->cmt_rst_ind_gpio);
+rback1:
+	kfree(cmt);
+
+	return err;
+}
+
+static int __exit cmt_remove(struct platform_device *pd)
+{
+	struct cmt_device *cmt = platform_get_drvdata(pd);
+
+	if (!cmt)
+		return 0;
+	platform_set_drvdata(pd, NULL);
+	list_del(&cmt->node);
+	disable_irq_wake(gpio_to_irq(cmt->cmt_rst_ind_gpio));
+	free_irq(gpio_to_irq(cmt->cmt_rst_ind_gpio), cmt);
+	tasklet_kill(&cmt->cmt_rst_ind_tasklet);
+	gpio_free(cmt->cmt_rst_ind_gpio);
+	kfree(cmt);
+
+	return 0;
+}
+
+static struct platform_driver cmt_driver = {
+	.remove = __exit_p(cmt_remove),
+	.driver = {
+		.name	= "cmt",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init cmt_init(void)
+{
+	pr_notice("CMT driver\n");
+
+	return platform_driver_probe(&cmt_driver, cmt_probe);
+}
+module_init(cmt_init);
+
+static void __exit cmt_exit(void)
+{
+	pr_notice("CMT driver exited\n");
+	platform_driver_unregister(&cmt_driver);
+}
+module_exit(cmt_exit);
+
+MODULE_AUTHOR("Carlos Chinea, Nokia");
+MODULE_DESCRIPTION("CMT related support");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/cmt.h b/include/linux/cmt.h
new file mode 100644
index 000000000000..90b3f5433f92
--- /dev/null
+++ b/include/linux/cmt.h
@@ -0,0 +1,53 @@
+/*
+ * cmt.h
+ *
+ * CMT support header
+ *
+ * Copyright (C) 2009 Nokia Corporation. All rights reserved.
+ *
+ * Contact: Carlos Chinea <carlos.chinea@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef __NOKIA_CMT_H__
+#define __NOKIA_CMT_H__
+
+#include <linux/notifier.h>
+
+/*
+ * NOKIA CMT notifier events
+ */
+enum {
+	CMT_RESET,
+};
+
+struct cmt_device;
+
+/*
+ * struct cmt_platform_data - CMT platform data
+ * @ape_rst_rq_gpio: GPIO line number for the CMT reset line
+ */
+struct cmt_platform_data {
+	unsigned int cmt_rst_ind_gpio;
+};
+
+struct cmt_device *cmt_get(const char *name);
+void cmt_put(struct cmt_device *cmt);
+int cmt_notifier_register(struct cmt_device *cmtdev,
+						struct notifier_block *nb);
+int cmt_notifier_unregister(struct cmt_device *cmtdev,
+						struct notifier_block *nb);
+#endif /* __NOKIA_CMT_H__ */