[PATCHv3 0/2] N900 Modem Speech Support

[PATCHv3 0/2] N900 Modem Speech Support

[Sebastian Reichel]

Hi,

This patchset contains the missing speech data support for the
Nokia N900 modem.

Userland access goes via /dev/cmt_speech. The API is implemented in
libcmtspeechdata, which is used by ofono and the freesmartphone.org project.
Apart from that the device is also used by the phone binaries distributed
with Maemo. So while this is a new userland ABI for the mainline kernel it
has been tested in the wild for some years.

Simple Testing of the API can be done by checking out libcmtspeechdata [0],
building the test tool and executing it. The tool will loop back audio data
received from the caller.

I have prepared a kernel branch for this patchset, which can be found at [1].

Changes since PATCHv2 [3]:
 * Change MODULE_LICENSE from "GPL" to "GPL v2"
 * Add some cleanups suggested by Pavel
 * Add missing dependency on SSI_PROTOCOL in Kconfig

Changes since PATCHv1 [2]:
 * Squash cmt-speech patches together
 * cs_alloc_cmds(): GFP_ATOMIC -> GFP_KERNEL
 * CS_SET_WAKELINE ioctl: Add sanity check

[0] https://lkml.org/lkml/2015/2/11/526
[1] git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-hsi.git branch/cmt-speech-2
[2] https://lkml.org/lkml/2015/3/1/282
[3] https://lkml.org/lkml/2015/3/4/1139

-- Sebastian

Kai Vehmanen (1):
  HSI: cmt_speech: Add cmt-speech driver

Sebastian Reichel (1):
  HSI: nokia-modem: Add cmt-speech support

 drivers/hsi/clients/Kconfig          |   12 +-
 drivers/hsi/clients/Makefile         |    1 +
 drivers/hsi/clients/cmt_speech.c     | 1456 ++++++++++++++++++++++++++++++++++
 drivers/hsi/clients/nokia-modem.c    |   32 +-
 include/uapi/linux/hsi/Kbuild        |    2 +-
 include/uapi/linux/hsi/cs-protocol.h |  113 +++
 6 files changed, 1613 insertions(+), 3 deletions(-)
 create mode 100644 drivers/hsi/clients/cmt_speech.c
 create mode 100644 include/uapi/linux/hsi/cs-protocol.h

-- 
2.1.4

[PATCHv3 1/2] HSI: cmt_speech: Add cmt-speech driver

[Sebastian Reichel]

From: Kai Vehmanen <kai.vehmanen@nokia.com>

Introduces the cmt-speech driver, which implements
a character device interface for transferring speech
data frames over HSI/SSI.

The driver is used to exchange voice/speech data between
the Nokia N900/N950/N9's modem and its cpu.

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

Since the original driver has been written for 2.6.28 some
build fixes and general cleanups have been added by me:

 * fix build for 4.0 kernel
 * replace GFP_ATOMIC with GFP_KERNEL in cs_alloc_cmds()
 * add sanity check for CS_SET_WAKELINE ioctl
 * cleanup driver initialisation
 * rename driver to cmt-speech to be consistent with
   ssi-protocol driver
 * move cs-protocol.h to include/uapi/linux/hsi, since
   it describes a userspace API
 * replace hardcoded channels numbers with values provided
   via the HSI framework (e.g. coming from DT)

Signed-off-by: Sebastian Reichel <sre@kernel.org>
---
 drivers/hsi/clients/Kconfig          |   10 +
 drivers/hsi/clients/Makefile         |    1 +
 drivers/hsi/clients/cmt_speech.c     | 1456 ++++++++++++++++++++++++++++++++++
 include/uapi/linux/hsi/Kbuild        |    2 +-
 include/uapi/linux/hsi/cs-protocol.h |  113 +++
 5 files changed, 1581 insertions(+), 1 deletion(-)
 create mode 100644 drivers/hsi/clients/cmt_speech.c
 create mode 100644 include/uapi/linux/hsi/cs-protocol.h

diff --git a/drivers/hsi/clients/Kconfig b/drivers/hsi/clients/Kconfig
index bc60dec..86c8495 100644
--- a/drivers/hsi/clients/Kconfig
+++ b/drivers/hsi/clients/Kconfig
@@ -13,6 +13,16 @@ config NOKIA_MODEM
 
 	If unsure, say N.
 
+config CMT_SPEECH
+	tristate "CMT speech"
+	depends on HSI && SSI_PROTOCOL
+	help
+	If you say Y here, you will enable the CMT speech protocol used
+	by Nokia modems. If you say M the protocol will be available as
+	module named cmt_speech.
+
+	If unsure, say N.
+
 config SSI_PROTOCOL
 	tristate "SSI protocol"
 	depends on HSI && PHONET && OMAP_SSI
diff --git a/drivers/hsi/clients/Makefile b/drivers/hsi/clients/Makefile
index 4d5bc0e..2607232 100644
--- a/drivers/hsi/clients/Makefile
+++ b/drivers/hsi/clients/Makefile
@@ -4,4 +4,5 @@
 
 obj-$(CONFIG_NOKIA_MODEM)	+= nokia-modem.o
 obj-$(CONFIG_SSI_PROTOCOL)	+= ssi_protocol.o
+obj-$(CONFIG_CMT_SPEECH)	+= cmt_speech.o
 obj-$(CONFIG_HSI_CHAR)		+= hsi_char.o
diff --git a/drivers/hsi/clients/cmt_speech.c b/drivers/hsi/clients/cmt_speech.c
new file mode 100644
index 0000000..e9560ef
--- /dev/null
+++ b/drivers/hsi/clients/cmt_speech.c
@@ -0,0 +1,1456 @@
+/*
+ * cmt_speech.c - HSI CMT speech driver
+ *
+ * Copyright (C) 2008,2009,2010 Nokia Corporation. All rights reserved.
+ *
+ * Contact: Kai Vehmanen <kai.vehmanen@nokia.com>
+ * Original author: Peter Ujfalusi <peter.ujfalusi@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 <linux/errno.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/ioctl.h>
+#include <linux/uaccess.h>
+#include <linux/pm_qos.h>
+#include <linux/hsi/hsi.h>
+#include <linux/hsi/ssi_protocol.h>
+#include <linux/hsi/cs-protocol.h>
+
+#define CS_MMAP_SIZE	PAGE_SIZE
+
+struct char_queue {
+	struct list_head	list;
+	u32			msg;
+};
+
+struct cs_char {
+	unsigned int		opened;
+	struct hsi_client	*cl;
+	struct cs_hsi_iface	*hi;
+	struct list_head	chardev_queue;
+	struct list_head	dataind_queue;
+	int			dataind_pending;
+	/* mmap things */
+	unsigned long		mmap_base;
+	unsigned long		mmap_size;
+	spinlock_t		lock;
+	struct fasync_struct	*async_queue;
+	wait_queue_head_t	wait;
+	/* hsi channel ids */
+	int                     channel_id_cmd;
+	int                     channel_id_data;
+};
+
+#define SSI_CHANNEL_STATE_READING	1
+#define SSI_CHANNEL_STATE_WRITING	(1 << 1)
+#define SSI_CHANNEL_STATE_POLL		(1 << 2)
+#define SSI_CHANNEL_STATE_ERROR		(1 << 3)
+
+#define TARGET_MASK			0xf000000
+#define TARGET_REMOTE			(1 << CS_DOMAIN_SHIFT)
+#define TARGET_LOCAL			0
+
+/* Number of pre-allocated commands buffers */
+#define CS_MAX_CMDS		        4
+
+/*
+ * During data transfers, transactions must be handled
+ * within 20ms (fixed value in cmtspeech HSI protocol)
+ */
+#define CS_QOS_LATENCY_FOR_DATA_USEC	20000
+
+/* Timeout to wait for pending HSI transfers to complete */
+#define CS_HSI_TRANSFER_TIMEOUT_MS      500
+
+
+#define RX_PTR_BOUNDARY_SHIFT		8
+#define RX_PTR_MAX_SHIFT		(RX_PTR_BOUNDARY_SHIFT + \
+						CS_MAX_BUFFERS_SHIFT)
+struct cs_hsi_iface {
+	struct hsi_client		*cl;
+	struct hsi_client		*master;
+
+	unsigned int			iface_state;
+	unsigned int			wakeline_state;
+	unsigned int			control_state;
+	unsigned int			data_state;
+
+	/* state exposed to application */
+	struct cs_mmap_config_block	*mmap_cfg;
+
+	unsigned long			mmap_base;
+	unsigned long			mmap_size;
+
+	unsigned int			rx_slot;
+	unsigned int			tx_slot;
+
+	/* note: for security reasons, we do not trust the contents of
+	 * mmap_cfg, but instead duplicate the variables here */
+	unsigned int			buf_size;
+	unsigned int			rx_bufs;
+	unsigned int			tx_bufs;
+	unsigned int			rx_ptr_boundary;
+	unsigned int			rx_offsets[CS_MAX_BUFFERS];
+	unsigned int			tx_offsets[CS_MAX_BUFFERS];
+
+	/* size of aligned memory blocks */
+	unsigned int			slot_size;
+	unsigned int			flags;
+
+	struct list_head		cmdqueue;
+
+	struct hsi_msg			*data_rx_msg;
+	struct hsi_msg			*data_tx_msg;
+	wait_queue_head_t		datawait;
+
+	struct pm_qos_request           pm_qos_req;
+
+	spinlock_t			lock;
+};
+
+static struct cs_char cs_char_data;
+
+static void cs_hsi_read_on_control(struct cs_hsi_iface *hi);
+static void cs_hsi_read_on_data(struct cs_hsi_iface *hi);
+
+static inline void rx_ptr_shift_too_big(void)
+{
+	BUILD_BUG_ON((1LLU << RX_PTR_MAX_SHIFT) > UINT_MAX);
+}
+
+static void cs_notify(u32 message, struct list_head *head)
+{
+	struct char_queue *entry;
+
+	spin_lock(&cs_char_data.lock);
+
+	if (!cs_char_data.opened) {
+		spin_unlock(&cs_char_data.lock);
+		goto out;
+	}
+
+	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
+	if (!entry) {
+		dev_err(&cs_char_data.cl->device,
+			"Can't allocate new entry for the queue.\n");
+		spin_unlock(&cs_char_data.lock);
+		goto out;
+	}
+
+	entry->msg = message;
+	list_add_tail(&entry->list, head);
+
+	spin_unlock(&cs_char_data.lock);
+
+	wake_up_interruptible(&cs_char_data.wait);
+	kill_fasync(&cs_char_data.async_queue, SIGIO, POLL_IN);
+
+out:
+	return;
+}
+
+static u32 cs_pop_entry(struct list_head *head)
+{
+	struct char_queue *entry;
+	u32 data;
+
+	entry = list_entry(head->next, struct char_queue, list);
+	data = entry->msg;
+	list_del(&entry->list);
+	kfree(entry);
+
+	return data;
+}
+
+static void cs_notify_control(u32 message)
+{
+	cs_notify(message, &cs_char_data.chardev_queue);
+}
+
+static void cs_notify_data(u32 message, int maxlength)
+{
+	cs_notify(message, &cs_char_data.dataind_queue);
+
+	spin_lock(&cs_char_data.lock);
+	cs_char_data.dataind_pending++;
+	while (cs_char_data.dataind_pending > maxlength &&
+				!list_empty(&cs_char_data.dataind_queue)) {
+		dev_dbg(&cs_char_data.cl->device, "data notification "
+		"queue overrun (%u entries)\n", cs_char_data.dataind_pending);
+
+		cs_pop_entry(&cs_char_data.dataind_queue);
+		cs_char_data.dataind_pending--;
+	}
+	spin_unlock(&cs_char_data.lock);
+}
+
+static inline void cs_set_cmd(struct hsi_msg *msg, u32 cmd)
+{
+	u32 *data = sg_virt(msg->sgt.sgl);
+	*data = cmd;
+}
+
+static inline u32 cs_get_cmd(struct hsi_msg *msg)
+{
+	u32 *data = sg_virt(msg->sgt.sgl);
+	return *data;
+}
+
+static void cs_release_cmd(struct hsi_msg *msg)
+{
+	struct cs_hsi_iface *hi = msg->context;
+
+	list_add_tail(&msg->link, &hi->cmdqueue);
+}
+
+static void cs_cmd_destructor(struct hsi_msg *msg)
+{
+	struct cs_hsi_iface *hi = msg->context;
+
+	spin_lock(&hi->lock);
+
+	dev_dbg(&cs_char_data.cl->device, "control cmd destructor\n");
+
+	if (hi->iface_state != CS_STATE_CLOSED)
+		dev_err(&hi->cl->device, "Cmd flushed while driver active\n");
+
+	if (msg->ttype == HSI_MSG_READ)
+		hi->control_state &=
+			~(SSI_CHANNEL_STATE_POLL | SSI_CHANNEL_STATE_READING);
+	else if (msg->ttype == HSI_MSG_WRITE &&
+			hi->control_state & SSI_CHANNEL_STATE_WRITING)
+		hi->control_state &= ~SSI_CHANNEL_STATE_WRITING;
+
+	cs_release_cmd(msg);
+
+	spin_unlock(&hi->lock);
+}
+
+static struct hsi_msg *cs_claim_cmd(struct cs_hsi_iface* ssi)
+{
+	struct hsi_msg *msg;
+
+	BUG_ON(list_empty(&ssi->cmdqueue));
+
+	msg = list_first_entry(&ssi->cmdqueue, struct hsi_msg, link);
+	list_del(&msg->link);
+	msg->destructor = cs_cmd_destructor;
+
+	return msg;
+}
+
+static void cs_free_cmds(struct cs_hsi_iface *ssi)
+{
+	struct hsi_msg *msg, *tmp;
+
+	list_for_each_entry_safe(msg, tmp, &ssi->cmdqueue, link) {
+		list_del(&msg->link);
+		msg->destructor = NULL;
+		kfree(sg_virt(msg->sgt.sgl));
+		hsi_free_msg(msg);
+	}
+}
+
+static int cs_alloc_cmds(struct cs_hsi_iface *hi)
+{
+	struct hsi_msg *msg;
+	u32 *buf;
+	unsigned int i;
+
+	INIT_LIST_HEAD(&hi->cmdqueue);
+
+	for (i = 0; i < CS_MAX_CMDS; i++) {
+		msg = hsi_alloc_msg(1, GFP_KERNEL);
+		if (!msg)
+			goto out;
+		buf = kmalloc(sizeof(*buf), GFP_KERNEL);
+		if (!buf) {
+			hsi_free_msg(msg);
+			goto out;
+		}
+		sg_init_one(msg->sgt.sgl, buf, sizeof(*buf));
+		msg->channel = cs_char_data.channel_id_cmd;
+		msg->context = hi;
+		list_add_tail(&msg->link, &hi->cmdqueue);
+	}
+
+	return 0;
+
+out:
+	cs_free_cmds(hi);
+	return -ENOMEM;
+}
+
+static void cs_hsi_data_destructor(struct hsi_msg *msg)
+{
+	struct cs_hsi_iface *hi = msg->context;
+	const char *dir = (msg->ttype == HSI_MSG_READ) ? "TX" : "RX";
+
+	dev_dbg(&cs_char_data.cl->device, "Freeing data %s message\n", dir);
+
+	spin_lock(&hi->lock);
+	if (hi->iface_state != CS_STATE_CLOSED)
+		dev_err(&cs_char_data.cl->device,
+				"Data %s flush while device active\n", dir);
+	if (msg->ttype == HSI_MSG_READ)
+		hi->data_state &=
+			~(SSI_CHANNEL_STATE_POLL | SSI_CHANNEL_STATE_READING);
+	else
+		hi->data_state &= ~SSI_CHANNEL_STATE_WRITING;
+
+	msg->status = HSI_STATUS_COMPLETED;
+	if (unlikely(waitqueue_active(&hi->datawait)))
+		wake_up_interruptible(&hi->datawait);
+
+	spin_unlock(&hi->lock);
+}
+
+static int cs_hsi_alloc_data(struct cs_hsi_iface *hi)
+{
+	struct hsi_msg *txmsg, *rxmsg;
+	int res = 0;
+
+	rxmsg = hsi_alloc_msg(1, GFP_KERNEL);
+	if (!rxmsg) {
+		res = -ENOMEM;
+		goto out1;
+	}
+	rxmsg->channel = cs_char_data.channel_id_data;
+	rxmsg->destructor = cs_hsi_data_destructor;
+	rxmsg->context = hi;
+
+	txmsg = hsi_alloc_msg(1, GFP_KERNEL);
+	if (!txmsg) {
+		res = -ENOMEM;
+		goto out2;
+	}
+	txmsg->channel = cs_char_data.channel_id_data;
+	txmsg->destructor = cs_hsi_data_destructor;
+	txmsg->context = hi;
+
+	hi->data_rx_msg = rxmsg;
+	hi->data_tx_msg = txmsg;
+
+	return 0;
+
+out2:
+	hsi_free_msg(rxmsg);
+out1:
+	return res;
+}
+
+static void cs_hsi_free_data_msg(struct hsi_msg *msg)
+{
+	WARN_ON(msg->status != HSI_STATUS_COMPLETED &&
+					msg->status != HSI_STATUS_ERROR);
+	hsi_free_msg(msg);
+}
+
+static void cs_hsi_free_data(struct cs_hsi_iface *hi)
+{
+	cs_hsi_free_data_msg(hi->data_rx_msg);
+	cs_hsi_free_data_msg(hi->data_tx_msg);
+}
+
+static inline void __cs_hsi_error_pre(struct cs_hsi_iface *hi,
+					struct hsi_msg *msg, const char *info,
+					unsigned int *state)
+{
+	spin_lock(&hi->lock);
+	dev_err(&hi->cl->device, "HSI %s error, msg %d, state %u\n",
+		info, msg->status, *state);
+}
+
+static inline void __cs_hsi_error_post(struct cs_hsi_iface *hi)
+{
+	spin_unlock(&hi->lock);
+}
+
+static inline void __cs_hsi_error_read_bits(unsigned int *state)
+{
+	*state |= SSI_CHANNEL_STATE_ERROR;
+	*state &= ~(SSI_CHANNEL_STATE_READING | SSI_CHANNEL_STATE_POLL);
+}
+
+static inline void __cs_hsi_error_write_bits(unsigned int *state)
+{
+	*state |= SSI_CHANNEL_STATE_ERROR;
+	*state &= ~SSI_CHANNEL_STATE_WRITING;
+}
+
+static void cs_hsi_control_read_error(struct cs_hsi_iface *hi,
+							struct hsi_msg *msg)
+{
+	__cs_hsi_error_pre(hi, msg, "control read", &hi->control_state);
+	cs_release_cmd(msg);
+	__cs_hsi_error_read_bits(&hi->control_state);
+	__cs_hsi_error_post(hi);
+}
+
+static void cs_hsi_control_write_error(struct cs_hsi_iface *hi,
+							struct hsi_msg *msg)
+{
+	__cs_hsi_error_pre(hi, msg, "control write", &hi->control_state);
+	cs_release_cmd(msg);
+	__cs_hsi_error_write_bits(&hi->control_state);
+	__cs_hsi_error_post(hi);
+
+}
+
+static void cs_hsi_data_read_error(struct cs_hsi_iface *hi, struct hsi_msg *msg)
+{
+	__cs_hsi_error_pre(hi, msg, "data read", &hi->data_state);
+	__cs_hsi_error_read_bits(&hi->data_state);
+	__cs_hsi_error_post(hi);
+}
+
+static void cs_hsi_data_write_error(struct cs_hsi_iface *hi,
+							struct hsi_msg *msg)
+{
+	__cs_hsi_error_pre(hi, msg, "data write", &hi->data_state);
+	__cs_hsi_error_write_bits(&hi->data_state);
+	__cs_hsi_error_post(hi);
+}
+
+static void cs_hsi_read_on_control_complete(struct hsi_msg *msg)
+{
+	u32 cmd = cs_get_cmd(msg);
+	struct cs_hsi_iface *hi = msg->context;
+
+	spin_lock(&hi->lock);
+	hi->control_state &= ~SSI_CHANNEL_STATE_READING;
+	if (msg->status == HSI_STATUS_ERROR) {
+		dev_err(&hi->cl->device, "Control RX error detected\n");
+		cs_hsi_control_read_error(hi, msg);
+		spin_unlock(&hi->lock);
+		goto out;
+	}
+	dev_dbg(&hi->cl->device, "Read on control: %08X\n", cmd);
+	cs_release_cmd(msg);
+	if (hi->flags & CS_FEAT_TSTAMP_RX_CTRL) {
+		struct timespec *tstamp =
+			&hi->mmap_cfg->tstamp_rx_ctrl;
+		do_posix_clock_monotonic_gettime(tstamp);
+	}
+	spin_unlock(&hi->lock);
+
+	cs_notify_control(cmd);
+
+out:
+	cs_hsi_read_on_control(hi);
+}
+
+static void cs_hsi_peek_on_control_complete(struct hsi_msg *msg)
+{
+	struct cs_hsi_iface *hi = msg->context;
+	int ret;
+
+	if (msg->status == HSI_STATUS_ERROR) {
+		dev_err(&hi->cl->device, "Control peek RX error detected\n");
+		cs_hsi_control_read_error(hi, msg);
+		return;
+	}
+
+	WARN_ON(!(hi->control_state & SSI_CHANNEL_STATE_READING));
+
+	dev_dbg(&hi->cl->device, "Peek on control complete, reading\n");
+	msg->sgt.nents = 1;
+	msg->complete = cs_hsi_read_on_control_complete;
+	ret = hsi_async_read(hi->cl, msg);
+	if (ret)
+		cs_hsi_control_read_error(hi, msg);
+}
+
+static void cs_hsi_read_on_control(struct cs_hsi_iface *hi)
+{
+	struct hsi_msg *msg;
+	int ret;
+
+	spin_lock(&hi->lock);
+	if (hi->control_state & SSI_CHANNEL_STATE_READING) {
+		dev_err(&hi->cl->device, "Control read already pending (%d)\n",
+			hi->control_state);
+		spin_unlock(&hi->lock);
+		return;
+	}
+	if (hi->control_state & SSI_CHANNEL_STATE_ERROR) {
+		dev_err(&hi->cl->device, "Control read error (%d)\n",
+			hi->control_state);
+		spin_unlock(&hi->lock);
+		return;
+	}
+	hi->control_state |= SSI_CHANNEL_STATE_READING;
+	dev_dbg(&hi->cl->device, "Issuing RX on control\n");
+	msg = cs_claim_cmd(hi);
+	spin_unlock(&hi->lock);
+
+	msg->sgt.nents = 0;
+	msg->complete = cs_hsi_peek_on_control_complete;
+	ret = hsi_async_read(hi->cl, msg);
+	if (ret)
+		cs_hsi_control_read_error(hi, msg);
+}
+
+static void cs_hsi_write_on_control_complete(struct hsi_msg *msg)
+{
+	struct cs_hsi_iface *hi = msg->context;
+	if (msg->status == HSI_STATUS_COMPLETED) {
+		spin_lock(&hi->lock);
+		hi->control_state &= ~SSI_CHANNEL_STATE_WRITING;
+		cs_release_cmd(msg);
+		spin_unlock(&hi->lock);
+	} else if (msg->status == HSI_STATUS_ERROR) {
+		cs_hsi_control_write_error(hi, msg);
+	} else {
+		dev_err(&hi->cl->device,
+			"unexpected status in control write callback %d\n",
+			msg->status);
+	}
+}
+
+static int cs_hsi_write_on_control(struct cs_hsi_iface *hi, u32 message)
+{
+	struct hsi_msg *msg;
+	int ret;
+
+	spin_lock(&hi->lock);
+	if (hi->control_state & SSI_CHANNEL_STATE_ERROR) {
+		spin_unlock(&hi->lock);
+		return -EIO;
+	}
+	if (hi->control_state & SSI_CHANNEL_STATE_WRITING) {
+		dev_err(&hi->cl->device,
+			"Write still pending on control channel.\n");
+		spin_unlock(&hi->lock);
+		return -EBUSY;
+	}
+	hi->control_state |= SSI_CHANNEL_STATE_WRITING;
+	msg = cs_claim_cmd(hi);
+	spin_unlock(&hi->lock);
+
+	cs_set_cmd(msg, message);
+	msg->sgt.nents = 1;
+	msg->complete = cs_hsi_write_on_control_complete;
+	dev_dbg(&hi->cl->device,
+		"Sending control message %08X\n", message);
+	ret = hsi_async_write(hi->cl, msg);
+	if (ret) {
+		dev_err(&hi->cl->device,
+			"async_write failed with %d\n", ret);
+		cs_hsi_control_write_error(hi, msg);
+	}
+
+	/*
+	 * Make sure control read is always pending when issuing
+	 * new control writes. This is needed as the controller
+	 * may flush our messages if e.g. the peer device reboots
+	 * unexpectedly (and we cannot directly resubmit a new read from
+	 * the message destructor; see cs_cmd_destructor()).
+	 */
+	if (!(hi->control_state & SSI_CHANNEL_STATE_READING)) {
+		dev_err(&hi->cl->device, "Restarting control reads\n");
+		cs_hsi_read_on_control(hi);
+	}
+
+	return 0;
+}
+
+static void cs_hsi_read_on_data_complete(struct hsi_msg *msg)
+{
+	struct cs_hsi_iface *hi = msg->context;
+	u32 payload;
+
+	if (unlikely(msg->status == HSI_STATUS_ERROR)) {
+		cs_hsi_data_read_error(hi, msg);
+		return;
+	}
+
+	spin_lock(&hi->lock);
+	WARN_ON(!(hi->data_state & SSI_CHANNEL_STATE_READING));
+	hi->data_state &= ~SSI_CHANNEL_STATE_READING;
+	payload = CS_RX_DATA_RECEIVED;
+	payload |= hi->rx_slot;
+	hi->rx_slot++;
+	hi->rx_slot %= hi->rx_ptr_boundary;
+	/* expose current rx ptr in mmap area */
+	hi->mmap_cfg->rx_ptr = hi->rx_slot;
+	if (unlikely(waitqueue_active(&hi->datawait)))
+		wake_up_interruptible(&hi->datawait);
+	spin_unlock(&hi->lock);
+
+	cs_notify_data(payload, hi->rx_bufs);
+	cs_hsi_read_on_data(hi);
+}
+
+static void cs_hsi_peek_on_data_complete(struct hsi_msg *msg)
+{
+	struct cs_hsi_iface *hi = msg->context;
+	u32 *address;
+	int ret;
+
+	if (unlikely(msg->status == HSI_STATUS_ERROR)) {
+		cs_hsi_data_read_error(hi, msg);
+		return;
+	}
+	if (unlikely(hi->iface_state != CS_STATE_CONFIGURED)) {
+		dev_err(&hi->cl->device, "Data received in invalid state\n");
+		cs_hsi_data_read_error(hi, msg);
+		return;
+	}
+
+	spin_lock(&hi->lock);
+	WARN_ON(!(hi->data_state & SSI_CHANNEL_STATE_POLL));
+	hi->data_state &= ~SSI_CHANNEL_STATE_POLL;
+	hi->data_state |= SSI_CHANNEL_STATE_READING;
+	spin_unlock(&hi->lock);
+
+	address = (u32 *)(hi->mmap_base +
+				hi->rx_offsets[hi->rx_slot % hi->rx_bufs]);
+	sg_init_one(msg->sgt.sgl, address, hi->buf_size);
+	msg->sgt.nents = 1;
+	msg->complete = cs_hsi_read_on_data_complete;
+	ret = hsi_async_read(hi->cl, msg);
+	if (ret)
+		cs_hsi_data_read_error(hi, msg);
+}
+
+/*
+ * Read/write transaction is ongoing. Returns false if in
+ * SSI_CHANNEL_STATE_POLL state.
+ */
+static inline int cs_state_xfer_active(unsigned int state)
+{
+	return (state & SSI_CHANNEL_STATE_WRITING) ||
+		(state & SSI_CHANNEL_STATE_READING);
+}
+
+/*
+ * No pending read/writes
+ */
+static inline int cs_state_idle(unsigned int state)
+{
+	return !(state & ~SSI_CHANNEL_STATE_ERROR);
+}
+
+static void cs_hsi_read_on_data(struct cs_hsi_iface *hi)
+{
+	struct hsi_msg *rxmsg;
+	int ret;
+
+	spin_lock(&hi->lock);
+	if (hi->data_state &
+		(SSI_CHANNEL_STATE_READING | SSI_CHANNEL_STATE_POLL)) {
+		dev_dbg(&hi->cl->device, "Data read already pending (%u)\n",
+			hi->data_state);
+		spin_unlock(&hi->lock);
+		return;
+	}
+	hi->data_state |= SSI_CHANNEL_STATE_POLL;
+	spin_unlock(&hi->lock);
+
+	rxmsg = hi->data_rx_msg;
+	sg_init_one(rxmsg->sgt.sgl, (void *)hi->mmap_base, 0);
+	rxmsg->sgt.nents = 0;
+	rxmsg->complete = cs_hsi_peek_on_data_complete;
+
+	ret = hsi_async_read(hi->cl, rxmsg);
+	if (ret)
+		cs_hsi_data_read_error(hi, rxmsg);
+}
+
+static void cs_hsi_write_on_data_complete(struct hsi_msg *msg)
+{
+	struct cs_hsi_iface *hi = msg->context;
+
+	if (msg->status == HSI_STATUS_COMPLETED) {
+		spin_lock(&hi->lock);
+		hi->data_state &= ~SSI_CHANNEL_STATE_WRITING;
+		if (unlikely(waitqueue_active(&hi->datawait)))
+			wake_up_interruptible(&hi->datawait);
+		spin_unlock(&hi->lock);
+	} else {
+		cs_hsi_data_write_error(hi, msg);
+	}
+}
+
+static int cs_hsi_write_on_data(struct cs_hsi_iface *hi, unsigned int slot)
+{
+	u32 *address;
+	struct hsi_msg *txmsg;
+	int ret;
+
+	spin_lock(&hi->lock);
+	if (hi->iface_state != CS_STATE_CONFIGURED) {
+		dev_err(&hi->cl->device, "Not configured, aborting\n");
+		ret = -EINVAL;
+		goto error;
+	}
+	if (hi->data_state & SSI_CHANNEL_STATE_ERROR) {
+		dev_err(&hi->cl->device, "HSI error, aborting\n");
+		ret = -EIO;
+		goto error;
+	}
+	if (hi->data_state & SSI_CHANNEL_STATE_WRITING) {
+		dev_err(&hi->cl->device, "Write pending on data channel.\n");
+		ret = -EBUSY;
+		goto error;
+	}
+	hi->data_state |= SSI_CHANNEL_STATE_WRITING;
+	spin_unlock(&hi->lock);
+
+	hi->tx_slot = slot;
+	address = (u32 *)(hi->mmap_base + hi->tx_offsets[hi->tx_slot]);
+	txmsg = hi->data_tx_msg;
+	sg_init_one(txmsg->sgt.sgl, address, hi->buf_size);
+	txmsg->complete = cs_hsi_write_on_data_complete;
+	ret = hsi_async_write(hi->cl, txmsg);
+	if (ret)
+		cs_hsi_data_write_error(hi, txmsg);
+
+	return ret;
+
+error:
+	spin_unlock(&hi->lock);
+	if (ret == -EIO)
+		cs_hsi_data_write_error(hi, hi->data_tx_msg);
+
+	return ret;
+}
+
+static unsigned int cs_hsi_get_state(struct cs_hsi_iface *hi)
+{
+	return hi->iface_state;
+}
+
+static int cs_hsi_command(struct cs_hsi_iface *hi, u32 cmd)
+{
+	int ret = 0;
+
+	local_bh_disable();
+	switch (cmd & TARGET_MASK) {
+	case TARGET_REMOTE:
+		ret = cs_hsi_write_on_control(hi, cmd);
+		break;
+	case TARGET_LOCAL:
+		if ((cmd & CS_CMD_MASK) == CS_TX_DATA_READY)
+			ret = cs_hsi_write_on_data(hi, cmd & CS_PARAM_MASK);
+		else
+			ret = -EINVAL;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	local_bh_enable();
+
+	return ret;
+}
+
+static void cs_hsi_set_wakeline(struct cs_hsi_iface *hi, bool new_state)
+{
+	int change = 0;
+
+	spin_lock_bh(&hi->lock);
+	if (hi->wakeline_state != new_state) {
+		hi->wakeline_state = new_state;
+		change = 1;
+		dev_dbg(&hi->cl->device, "setting wake line to %d (%p)\n",
+			new_state, hi->cl);
+	}
+	spin_unlock_bh(&hi->lock);
+
+	if (change) {
+		if (new_state)
+			ssip_slave_start_tx(hi->master);
+		else
+			ssip_slave_stop_tx(hi->master);
+	}
+
+	dev_dbg(&hi->cl->device, "wake line set to %d (%p)\n",
+		new_state, hi->cl);
+}
+
+static void set_buffer_sizes(struct cs_hsi_iface *hi, int rx_bufs, int tx_bufs)
+{
+	hi->rx_bufs = rx_bufs;
+	hi->tx_bufs = tx_bufs;
+	hi->mmap_cfg->rx_bufs = rx_bufs;
+	hi->mmap_cfg->tx_bufs = tx_bufs;
+
+	if (hi->flags & CS_FEAT_ROLLING_RX_COUNTER) {
+		/*
+		 * For more robust overrun detection, let the rx
+		 * pointer run in range 0..'boundary-1'. Boundary
+		 * is a multiple of rx_bufs, and limited in max size
+		 * by RX_PTR_MAX_SHIFT to allow for fast ptr-diff
+		 * calculation.
+		 */
+		hi->rx_ptr_boundary = (rx_bufs << RX_PTR_BOUNDARY_SHIFT);
+		hi->mmap_cfg->rx_ptr_boundary = hi->rx_ptr_boundary;
+	} else {
+		hi->rx_ptr_boundary = hi->rx_bufs;
+	}
+}
+
+static int check_buf_params(struct cs_hsi_iface *hi,
+					const struct cs_buffer_config *buf_cfg)
+{
+	size_t buf_size_aligned = L1_CACHE_ALIGN(buf_cfg->buf_size) *
+					(buf_cfg->rx_bufs + buf_cfg->tx_bufs);
+	size_t ctrl_size_aligned = L1_CACHE_ALIGN(sizeof(*hi->mmap_cfg));
+	int r = 0;
+
+	if (buf_cfg->rx_bufs > CS_MAX_BUFFERS ||
+					buf_cfg->tx_bufs > CS_MAX_BUFFERS) {
+		r = -EINVAL;
+	} else if ((buf_size_aligned + ctrl_size_aligned) >= hi->mmap_size) {
+		dev_err(&hi->cl->device, "No space for the requested buffer "
+			"configuration\n");
+		r = -ENOBUFS;
+	}
+
+	return r;
+}
+
+/**
+ * Block until pending data transfers have completed.
+ */
+static int cs_hsi_data_sync(struct cs_hsi_iface *hi)
+{
+	int r = 0;
+
+	spin_lock_bh(&hi->lock);
+
+	if (!cs_state_xfer_active(hi->data_state)) {
+		dev_dbg(&hi->cl->device, "hsi_data_sync break, idle\n");
+		goto out;
+	}
+
+	for (;;) {
+		int s;
+		DEFINE_WAIT(wait);
+		if (!cs_state_xfer_active(hi->data_state))
+			goto out;
+		if (signal_pending(current)) {
+			r = -ERESTARTSYS;
+			goto out;
+		}
+		/**
+		 * prepare_to_wait must be called with hi->lock held
+		 * so that callbacks can check for waitqueue_active()
+		 */
+		prepare_to_wait(&hi->datawait, &wait, TASK_INTERRUPTIBLE);
+		spin_unlock_bh(&hi->lock);
+		s = schedule_timeout(
+			msecs_to_jiffies(CS_HSI_TRANSFER_TIMEOUT_MS));
+		spin_lock_bh(&hi->lock);
+		finish_wait(&hi->datawait, &wait);
+		if (!s) {
+			dev_dbg(&hi->cl->device,
+				"hsi_data_sync timeout after %d ms\n",
+				CS_HSI_TRANSFER_TIMEOUT_MS);
+			r = -EIO;
+			goto out;
+		}
+	}
+
+out:
+	spin_unlock_bh(&hi->lock);
+	dev_dbg(&hi->cl->device, "hsi_data_sync done with res %d\n", r);
+
+	return r;
+}
+
+static void cs_hsi_data_enable(struct cs_hsi_iface *hi,
+					struct cs_buffer_config *buf_cfg)
+{
+	unsigned int data_start, i;
+
+	BUG_ON(hi->buf_size == 0);
+
+	set_buffer_sizes(hi, buf_cfg->rx_bufs, buf_cfg->tx_bufs);
+
+	hi->slot_size = L1_CACHE_ALIGN(hi->buf_size);
+	dev_dbg(&hi->cl->device,
+			"setting slot size to %u, buf size %u, align %u\n",
+			hi->slot_size, hi->buf_size, L1_CACHE_BYTES);
+
+	data_start = L1_CACHE_ALIGN(sizeof(*hi->mmap_cfg));
+	dev_dbg(&hi->cl->device,
+			"setting data start at %u, cfg block %u, align %u\n",
+			data_start, sizeof(*hi->mmap_cfg), L1_CACHE_BYTES);
+
+	for (i = 0; i < hi->mmap_cfg->rx_bufs; i++) {
+		hi->rx_offsets[i] = data_start + i * hi->slot_size;
+		hi->mmap_cfg->rx_offsets[i] = hi->rx_offsets[i];
+		dev_dbg(&hi->cl->device, "DL buf #%u at %u\n",
+					i, hi->rx_offsets[i]);
+	}
+	for (i = 0; i < hi->mmap_cfg->tx_bufs; i++) {
+		hi->tx_offsets[i] = data_start +
+			(i + hi->mmap_cfg->rx_bufs) * hi->slot_size;
+		hi->mmap_cfg->tx_offsets[i] = hi->tx_offsets[i];
+		dev_dbg(&hi->cl->device, "UL buf #%u at %u\n",
+					i, hi->rx_offsets[i]);
+	}
+
+	hi->iface_state = CS_STATE_CONFIGURED;
+}
+
+static void cs_hsi_data_disable(struct cs_hsi_iface *hi, int old_state)
+{
+	if (old_state == CS_STATE_CONFIGURED) {
+		dev_dbg(&hi->cl->device,
+			"closing data channel with slot size 0\n");
+		hi->iface_state = CS_STATE_OPENED;
+	}
+}
+
+static int cs_hsi_buf_config(struct cs_hsi_iface *hi,
+					struct cs_buffer_config *buf_cfg)
+{
+	int r = 0;
+	unsigned int old_state = hi->iface_state;
+
+	spin_lock_bh(&hi->lock);
+	/* Prevent new transactions during buffer reconfig */
+	if (old_state == CS_STATE_CONFIGURED)
+		hi->iface_state = CS_STATE_OPENED;
+	spin_unlock_bh(&hi->lock);
+
+	/*
+	 * make sure that no non-zero data reads are ongoing before
+	 * proceeding to change the buffer layout
+	 */
+	r = cs_hsi_data_sync(hi);
+	if (r < 0)
+		return r;
+
+	WARN_ON(cs_state_xfer_active(hi->data_state));
+
+	spin_lock_bh(&hi->lock);
+	r = check_buf_params(hi, buf_cfg);
+	if (r < 0)
+		goto error;
+
+	hi->buf_size = buf_cfg->buf_size;
+	hi->mmap_cfg->buf_size = hi->buf_size;
+	hi->flags = buf_cfg->flags;
+
+	hi->rx_slot = 0;
+	hi->tx_slot = 0;
+	hi->slot_size = 0;
+
+	if (hi->buf_size)
+		cs_hsi_data_enable(hi, buf_cfg);
+	else
+		cs_hsi_data_disable(hi, old_state);
+
+	spin_unlock_bh(&hi->lock);
+
+	if (old_state != hi->iface_state) {
+		if (hi->iface_state == CS_STATE_CONFIGURED) {
+			pm_qos_add_request(&hi->pm_qos_req,
+				PM_QOS_CPU_DMA_LATENCY,
+				CS_QOS_LATENCY_FOR_DATA_USEC);
+			local_bh_disable();
+			cs_hsi_read_on_data(hi);
+			local_bh_enable();
+		} else if (old_state == CS_STATE_CONFIGURED) {
+			pm_qos_remove_request(&hi->pm_qos_req);
+		}
+	}
+	return r;
+
+error:
+	spin_unlock_bh(&hi->lock);
+	return r;
+}
+
+static int cs_hsi_start(struct cs_hsi_iface **hi, struct hsi_client *cl,
+			unsigned long mmap_base, unsigned long mmap_size)
+{
+	int err = 0;
+	struct cs_hsi_iface *hsi_if = kzalloc(sizeof(*hsi_if), GFP_KERNEL);
+
+	dev_dbg(&cl->device, "cs_hsi_start\n");
+
+	if (!hsi_if) {
+		err = -ENOMEM;
+		goto leave0;
+	}
+	spin_lock_init(&hsi_if->lock);
+	hsi_if->cl = cl;
+	hsi_if->iface_state = CS_STATE_CLOSED;
+	hsi_if->mmap_cfg = (struct cs_mmap_config_block *)mmap_base;
+	hsi_if->mmap_base = mmap_base;
+	hsi_if->mmap_size = mmap_size;
+	memset(hsi_if->mmap_cfg, 0, sizeof(*hsi_if->mmap_cfg));
+	init_waitqueue_head(&hsi_if->datawait);
+	err = cs_alloc_cmds(hsi_if);
+	if (err < 0) {
+		dev_err(&cl->device, "Unable to alloc HSI messages\n");
+		goto leave1;
+	}
+	err = cs_hsi_alloc_data(hsi_if);
+	if (err < 0) {
+		dev_err(&cl->device, "Unable to alloc HSI messages for data\n");
+		goto leave2;
+	}
+	err = hsi_claim_port(cl, 1);
+	if (err < 0) {
+		dev_err(&cl->device,
+				"Could not open, HSI port already claimed\n");
+		goto leave3;
+	}
+	hsi_if->master = ssip_slave_get_master(cl);
+	if (IS_ERR(hsi_if->master)) {
+		dev_err(&cl->device, "Could not get HSI master client\n");
+		goto leave4;
+	}
+	if (!ssip_slave_running(hsi_if->master)) {
+		err = -ENODEV;
+		dev_err(&cl->device,
+				"HSI port not initialized\n");
+		goto leave4;
+	}
+
+	hsi_if->iface_state = CS_STATE_OPENED;
+	local_bh_disable();
+	cs_hsi_read_on_control(hsi_if);
+	local_bh_enable();
+
+	dev_dbg(&cl->device, "cs_hsi_start...done\n");
+
+	BUG_ON(!hi);
+	*hi = hsi_if;
+
+	return 0;
+
+leave4:
+	hsi_release_port(cl);
+leave3:
+	cs_hsi_free_data(hsi_if);
+leave2:
+	cs_free_cmds(hsi_if);
+leave1:
+	kfree(hsi_if);
+leave0:
+	dev_dbg(&cl->device, "cs_hsi_start...done/error\n\n");
+
+	return err;
+}
+
+static void cs_hsi_stop(struct cs_hsi_iface *hi)
+{
+	dev_dbg(&hi->cl->device, "cs_hsi_stop\n");
+	cs_hsi_set_wakeline(hi, 0);
+	ssip_slave_put_master(hi->master);
+
+	/* hsi_release_port() needs to be called with CS_STATE_CLOSED */
+	hi->iface_state = CS_STATE_CLOSED;
+	hsi_release_port(hi->cl);
+
+	/*
+	 * hsi_release_port() should flush out all the pending
+	 * messages, so cs_state_idle() should be true for both
+	 * control and data channels.
+	 */
+	WARN_ON(!cs_state_idle(hi->control_state));
+	WARN_ON(!cs_state_idle(hi->data_state));
+
+	if (pm_qos_request_active(&hi->pm_qos_req))
+		pm_qos_remove_request(&hi->pm_qos_req);
+
+	spin_lock_bh(&hi->lock);
+	cs_hsi_free_data(hi);
+	cs_free_cmds(hi);
+	spin_unlock_bh(&hi->lock);
+	kfree(hi);
+}
+
+static int cs_char_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct cs_char *csdata = vma->vm_private_data;
+	struct page *page;
+
+	page = virt_to_page(csdata->mmap_base);
+	get_page(page);
+	vmf->page = page;
+
+	return 0;
+}
+
+static struct vm_operations_struct cs_char_vm_ops = {
+	.fault	= cs_char_vma_fault,
+};
+
+static int cs_char_fasync(int fd, struct file *file, int on)
+{
+	struct cs_char *csdata = file->private_data;
+
+	if (fasync_helper(fd, file, on, &csdata->async_queue) < 0)
+		return -EIO;
+
+	return 0;
+}
+
+static unsigned int cs_char_poll(struct file *file, poll_table *wait)
+{
+	struct cs_char *csdata = file->private_data;
+	unsigned int ret = 0;
+
+	poll_wait(file, &cs_char_data.wait, wait);
+	spin_lock_bh(&csdata->lock);
+	if (!list_empty(&csdata->chardev_queue))
+		ret = POLLIN | POLLRDNORM;
+	else if (!list_empty(&csdata->dataind_queue))
+		ret = POLLIN | POLLRDNORM;
+	spin_unlock_bh(&csdata->lock);
+
+	return ret;
+}
+
+static ssize_t cs_char_read(struct file *file, char __user *buf, size_t count,
+								loff_t *unused)
+{
+	struct cs_char *csdata = file->private_data;
+	u32 data;
+	ssize_t retval;
+
+	if (count < sizeof(data))
+		return -EINVAL;
+
+	for (;;) {
+		DEFINE_WAIT(wait);
+
+		spin_lock_bh(&csdata->lock);
+		if (!list_empty(&csdata->chardev_queue)) {
+			data = cs_pop_entry(&csdata->chardev_queue);
+		} else if (!list_empty(&csdata->dataind_queue)) {
+			data = cs_pop_entry(&csdata->dataind_queue);
+			csdata->dataind_pending--;
+		} else {
+			data = 0;
+		}
+		spin_unlock_bh(&csdata->lock);
+
+		if (data)
+			break;
+		if (file->f_flags & O_NONBLOCK) {
+			retval = -EAGAIN;
+			goto out;
+		} else if (signal_pending(current)) {
+			retval = -ERESTARTSYS;
+			goto out;
+		}
+		prepare_to_wait_exclusive(&csdata->wait, &wait,
+						TASK_INTERRUPTIBLE);
+		schedule();
+		finish_wait(&csdata->wait, &wait);
+	}
+
+	retval = put_user(data, (u32 __user *)buf);
+	if (!retval)
+		retval = sizeof(data);
+
+out:
+	return retval;
+}
+
+static ssize_t cs_char_write(struct file *file, const char __user *buf,
+						size_t count, loff_t *unused)
+{
+	struct cs_char *csdata = file->private_data;
+	u32 data;
+	int err;
+	ssize_t	retval;
+
+	if (count < sizeof(data))
+		return -EINVAL;
+
+	if (get_user(data, (u32 __user *)buf))
+		retval = -EFAULT;
+	else
+		retval = count;
+
+	err = cs_hsi_command(csdata->hi, data);
+	if (err < 0)
+		retval = err;
+
+	return retval;
+}
+
+static long cs_char_ioctl(struct file *file, unsigned int cmd,
+				unsigned long arg)
+{
+	struct cs_char *csdata = file->private_data;
+	int r = 0;
+
+	switch (cmd) {
+	case CS_GET_STATE: {
+		unsigned int state;
+
+		state = cs_hsi_get_state(csdata->hi);
+		if (copy_to_user((void __user *)arg, &state, sizeof(state)))
+			r = -EFAULT;
+
+		break;
+	}
+	case CS_SET_WAKELINE: {
+		unsigned int state;
+
+		if (copy_from_user(&state, (void __user *)arg, sizeof(state))) {
+			r = -EFAULT;
+			break;
+		}
+
+		if (state > 1) {
+			r = -EINVAL;
+			break;
+		}
+
+		cs_hsi_set_wakeline(csdata->hi, !!state);
+
+		break;
+	}
+	case CS_GET_IF_VERSION: {
+		unsigned int ifver = CS_IF_VERSION;
+
+		if (copy_to_user((void __user *)arg, &ifver, sizeof(ifver)))
+			r = -EFAULT;
+
+		break;
+	}
+	case CS_CONFIG_BUFS: {
+		struct cs_buffer_config buf_cfg;
+
+		if (copy_from_user(&buf_cfg, (void __user *)arg,
+							sizeof(buf_cfg)))
+			r = -EFAULT;
+		else
+			r = cs_hsi_buf_config(csdata->hi, &buf_cfg);
+
+		break;
+	}
+	default:
+		r = -ENOTTY;
+		break;
+	}
+
+	return r;
+}
+
+static int cs_char_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	if (vma->vm_end < vma->vm_start)
+		return -EINVAL;
+
+	if (((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) != 1)
+		return -EINVAL;
+
+	vma->vm_flags |= VM_IO | VM_DONTDUMP | VM_DONTEXPAND;
+	vma->vm_ops = &cs_char_vm_ops;
+	vma->vm_private_data = file->private_data;
+
+	return 0;
+}
+
+static int cs_char_open(struct inode *unused, struct file *file)
+{
+	int ret = 0;
+	unsigned long p;
+
+	spin_lock_bh(&cs_char_data.lock);
+	if (cs_char_data.opened) {
+		ret = -EBUSY;
+		spin_unlock_bh(&cs_char_data.lock);
+		goto out1;
+	}
+	cs_char_data.opened = 1;
+	cs_char_data.dataind_pending = 0;
+	spin_unlock_bh(&cs_char_data.lock);
+
+	p = get_zeroed_page(GFP_KERNEL);
+	if (!p) {
+		ret = -ENOMEM;
+		goto out2;
+	}
+
+	ret = cs_hsi_start(&cs_char_data.hi, cs_char_data.cl, p, CS_MMAP_SIZE);
+	if (ret) {
+		dev_err(&cs_char_data.cl->device, "Unable to initialize HSI\n");
+		goto out3;
+	}
+
+	/* these are only used in release so lock not needed */
+	cs_char_data.mmap_base = p;
+	cs_char_data.mmap_size = CS_MMAP_SIZE;
+
+	file->private_data = &cs_char_data;
+
+	return 0;
+
+out3:
+	free_page(p);
+out2:
+	spin_lock_bh(&cs_char_data.lock);
+	cs_char_data.opened = 0;
+	spin_unlock_bh(&cs_char_data.lock);
+out1:
+	return ret;
+}
+
+static void cs_free_char_queue(struct list_head *head)
+{
+	struct char_queue *entry;
+	struct list_head *cursor, *next;
+
+	if (!list_empty(head)) {
+		list_for_each_safe(cursor, next, head) {
+			entry = list_entry(cursor, struct char_queue, list);
+			list_del(&entry->list);
+			kfree(entry);
+		}
+	}
+
+}
+
+static int cs_char_release(struct inode *unused, struct file *file)
+{
+	struct cs_char *csdata = file->private_data;
+
+	cs_hsi_stop(csdata->hi);
+	spin_lock_bh(&csdata->lock);
+	csdata->hi = NULL;
+	free_page(csdata->mmap_base);
+	cs_free_char_queue(&csdata->chardev_queue);
+	cs_free_char_queue(&csdata->dataind_queue);
+	csdata->opened = 0;
+	spin_unlock_bh(&csdata->lock);
+
+	return 0;
+}
+
+static const struct file_operations cs_char_fops = {
+	.owner		= THIS_MODULE,
+	.read		= cs_char_read,
+	.write		= cs_char_write,
+	.poll		= cs_char_poll,
+	.unlocked_ioctl	= cs_char_ioctl,
+	.mmap		= cs_char_mmap,
+	.open		= cs_char_open,
+	.release	= cs_char_release,
+	.fasync		= cs_char_fasync,
+};
+
+static struct miscdevice cs_char_miscdev = {
+	.minor	= MISC_DYNAMIC_MINOR,
+	.name	= "cmt_speech",
+	.fops	= &cs_char_fops
+};
+
+static int cs_hsi_client_probe(struct device *dev)
+{
+	int err = 0;
+	struct hsi_client *cl = to_hsi_client(dev);
+
+	dev_dbg(dev, "hsi_client_probe\n");
+	init_waitqueue_head(&cs_char_data.wait);
+	spin_lock_init(&cs_char_data.lock);
+	cs_char_data.opened = 0;
+	cs_char_data.cl = cl;
+	cs_char_data.hi = NULL;
+	INIT_LIST_HEAD(&cs_char_data.chardev_queue);
+	INIT_LIST_HEAD(&cs_char_data.dataind_queue);
+
+	cs_char_data.channel_id_cmd = hsi_get_channel_id_by_name(cl,
+		"speech-control");
+	if (cs_char_data.channel_id_cmd < 0) {
+		err = cs_char_data.channel_id_cmd;
+		dev_err(dev, "Could not get cmd channel (%d)\n", err);
+		return err;
+	}
+
+	cs_char_data.channel_id_data = hsi_get_channel_id_by_name(cl,
+		"speech-data");
+	if (cs_char_data.channel_id_data < 0) {
+		err = cs_char_data.channel_id_data;
+		dev_err(dev, "Could not get data channel (%d)\n", err);
+		return err;
+	}
+
+	err = misc_register(&cs_char_miscdev);
+	if (err)
+		dev_err(dev, "Failed to register: %d\n", err);
+
+	return err;
+}
+
+static int cs_hsi_client_remove(struct device *dev)
+{
+	struct cs_hsi_iface *hi;
+
+	dev_dbg(dev, "hsi_client_remove\n");
+	misc_deregister(&cs_char_miscdev);
+	spin_lock_bh(&cs_char_data.lock);
+	hi = cs_char_data.hi;
+	cs_char_data.hi = NULL;
+	spin_unlock_bh(&cs_char_data.lock);
+	if (hi)
+		cs_hsi_stop(hi);
+
+	return 0;
+}
+
+static struct hsi_client_driver cs_hsi_driver = {
+	.driver = {
+		.name	= "cmt-speech",
+		.owner	= THIS_MODULE,
+		.probe	= cs_hsi_client_probe,
+		.remove	= cs_hsi_client_remove,
+	},
+};
+
+static int __init cs_char_init(void)
+{
+	pr_info("CMT speech driver added\n");
+	return hsi_register_client_driver(&cs_hsi_driver);
+}
+module_init(cs_char_init);
+
+static void __exit cs_char_exit(void)
+{
+	hsi_unregister_client_driver(&cs_hsi_driver);
+	pr_info("CMT speech driver removed\n");
+}
+module_exit(cs_char_exit);
+
+MODULE_ALIAS("hsi:cmt-speech");
+MODULE_AUTHOR("Kai Vehmanen <kai.vehmanen@nokia.com>");
+MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@nokia.com>");
+MODULE_DESCRIPTION("CMT speech driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/uapi/linux/hsi/Kbuild b/include/uapi/linux/hsi/Kbuild
index 30ab3cd..a16a005 100644
--- a/include/uapi/linux/hsi/Kbuild
+++ b/include/uapi/linux/hsi/Kbuild
@@ -1,2 +1,2 @@
 # UAPI Header export list
-header-y += hsi_char.h
+header-y += hsi_char.h cs-protocol.h
diff --git a/include/uapi/linux/hsi/cs-protocol.h b/include/uapi/linux/hsi/cs-protocol.h
new file mode 100644
index 0000000..4957bba
--- /dev/null
+++ b/include/uapi/linux/hsi/cs-protocol.h
@@ -0,0 +1,113 @@
+/*
+ * cmt-speech interface definitions
+ *
+ * Copyright (C) 2008,2009,2010 Nokia Corporation. All rights reserved.
+ *
+ * Contact: Kai Vehmanen <kai.vehmanen@nokia.com>
+ * Original author: Peter Ujfalusi <peter.ujfalusi@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 _CS_PROTOCOL_H
+#define _CS_PROTOCOL_H
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+/* chardev parameters */
+#define CS_DEV_FILE_NAME		"/dev/cmt_speech"
+
+/* user-space API versioning */
+#define CS_IF_VERSION			2
+
+/* APE kernel <-> user space messages */
+#define CS_CMD_SHIFT			28
+#define CS_DOMAIN_SHIFT			24
+
+#define CS_CMD_MASK			0xff000000
+#define CS_PARAM_MASK			0xffffff
+
+#define CS_CMD(id, dom) \
+	(((id) << CS_CMD_SHIFT) | ((dom) << CS_DOMAIN_SHIFT))
+
+#define CS_ERROR			CS_CMD(1, 0)
+#define CS_RX_DATA_RECEIVED		CS_CMD(2, 0)
+#define CS_TX_DATA_READY		CS_CMD(3, 0)
+#define CS_TX_DATA_SENT			CS_CMD(4, 0)
+
+/* params to CS_ERROR indication */
+#define CS_ERR_PEER_RESET		0
+
+/* ioctl interface */
+
+/* parameters to CS_CONFIG_BUFS ioctl */
+#define CS_FEAT_TSTAMP_RX_CTRL		(1 << 0)
+#define CS_FEAT_ROLLING_RX_COUNTER	(2 << 0)
+
+/* parameters to CS_GET_STATE ioctl */
+#define CS_STATE_CLOSED			0
+#define CS_STATE_OPENED			1 /* resource allocated */
+#define CS_STATE_CONFIGURED		2 /* data path active */
+
+/* maximum number of TX/RX buffers */
+#define CS_MAX_BUFFERS_SHIFT		4
+#define CS_MAX_BUFFERS			(1 << CS_MAX_BUFFERS_SHIFT)
+
+/* Parameters for setting up the data buffers */
+struct cs_buffer_config {
+	__u32 rx_bufs;	/* number of RX buffer slots */
+	__u32 tx_bufs;	/* number of TX buffer slots */
+	__u32 buf_size;	/* bytes */
+	__u32 flags;	/* see CS_FEAT_* */
+	__u32 reserved[4];
+};
+
+/*
+ * Struct describing the layout and contents of the driver mmap area.
+ * This information is meant as read-only information for the application.
+ */
+struct cs_mmap_config_block {
+	__u32 reserved1;
+	__u32 buf_size;		/* 0=disabled, otherwise the transfer size */
+	__u32 rx_bufs;		/* # of RX buffers */
+	__u32 tx_bufs;		/* # of TX buffers */
+	__u32 reserved2;
+	/* array of offsets within the mmap area for each RX and TX buffer */
+	__u32 rx_offsets[CS_MAX_BUFFERS];
+	__u32 tx_offsets[CS_MAX_BUFFERS];
+	__u32 rx_ptr;
+	__u32 rx_ptr_boundary;
+	__u32 reserved3[2];
+	/*
+	 * if enabled with CS_FEAT_TSTAMP_RX_CTRL, monotonic
+	 * timestamp taken when the last control command was received
+	 */
+	struct timespec tstamp_rx_ctrl;
+};
+
+#define CS_IO_MAGIC		'C'
+
+#define CS_IOW(num, dtype)	_IOW(CS_IO_MAGIC, num, dtype)
+#define CS_IOR(num, dtype)	_IOR(CS_IO_MAGIC, num, dtype)
+#define CS_IOWR(num, dtype)	_IOWR(CS_IO_MAGIC, num, dtype)
+#define CS_IO(num)		_IO(CS_IO_MAGIC, num)
+
+#define CS_GET_STATE		CS_IOR(21, unsigned int)
+#define CS_SET_WAKELINE		CS_IOW(23, unsigned int)
+#define CS_GET_IF_VERSION	CS_IOR(30, unsigned int)
+#define CS_CONFIG_BUFS		CS_IOW(31, struct cs_buffer_config)
+
+#endif /* _CS_PROTOCOL_H */
-- 
2.1.4

[PATCHv3 2/2] HSI: nokia-modem: Add cmt-speech support

[Sebastian Reichel]

Register cmt-speech driver in nokia-modem driver and forward
hsi channel information.

Signed-off-by: Sebastian Reichel <sre@kernel.org>
---
 drivers/hsi/clients/Kconfig       |  2 +-
 drivers/hsi/clients/nokia-modem.c | 32 +++++++++++++++++++++++++++++++-
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/drivers/hsi/clients/Kconfig b/drivers/hsi/clients/Kconfig
index 86c8495..d612620 100644
--- a/drivers/hsi/clients/Kconfig
+++ b/drivers/hsi/clients/Kconfig
@@ -6,7 +6,7 @@ comment "HSI clients"
 
 config NOKIA_MODEM
 	tristate "Nokia Modem"
-	depends on HSI && SSI_PROTOCOL
+	depends on HSI && SSI_PROTOCOL && CMT_SPEECH
 	help
 	Say Y here if you want to add support for the modem on Nokia
 	N900 (Nokia RX-51) hardware.
diff --git a/drivers/hsi/clients/nokia-modem.c b/drivers/hsi/clients/nokia-modem.c
index 9be4867..bbb1923 100644
--- a/drivers/hsi/clients/nokia-modem.c
+++ b/drivers/hsi/clients/nokia-modem.c
@@ -46,6 +46,7 @@ struct nokia_modem_device {
 	struct nokia_modem_gpio	*gpios;
 	int			gpio_amount;
 	struct hsi_client	*ssi_protocol;
+	struct hsi_client	*cmt_speech;
 };
 
 static void do_nokia_modem_rst_ind_tasklet(unsigned long data)
@@ -149,6 +150,7 @@ static int nokia_modem_probe(struct device *dev)
 	struct hsi_port *port = hsi_get_port(cl);
 	int irq, pflags, err;
 	struct hsi_board_info ssip;
+	struct hsi_board_info cmtspeech;
 
 	np = dev->of_node;
 	if (!np) {
@@ -214,12 +216,35 @@ static int nokia_modem_probe(struct device *dev)
 		goto error3;
 	}
 
-	/* TODO: register cmt-speech hsi client */
+	cmtspeech.name = "cmt-speech";
+	cmtspeech.tx_cfg = cl->tx_cfg;
+	cmtspeech.rx_cfg = cl->rx_cfg;
+	cmtspeech.platform_data = NULL;
+	cmtspeech.archdata = NULL;
+
+	modem->cmt_speech = hsi_new_client(port, &cmtspeech);
+	if (!modem->cmt_speech) {
+		dev_err(dev, "Could not register cmt-speech device\n");
+		err = -ENOMEM;
+		goto error3;
+	}
+
+	err = device_attach(&modem->cmt_speech->device);
+	if (err == 0) {
+		dev_err(dev, "Missing cmt-speech driver\n");
+		err = -EPROBE_DEFER;
+		goto error4;
+	} else if (err < 0) {
+		dev_err(dev, "Could not load cmt-speech driver (%d)\n", err);
+		goto error4;
+	}
 
 	dev_info(dev, "Registered Nokia HSI modem\n");
 
 	return 0;
 
+error4:
+	hsi_remove_client(&modem->cmt_speech->device, NULL);
 error3:
 	hsi_remove_client(&modem->ssi_protocol->device, NULL);
 error2:
@@ -238,6 +263,11 @@ static int nokia_modem_remove(struct device *dev)
 	if (!modem)
 		return 0;
 
+	if (modem->cmt_speech) {
+		hsi_remove_client(&modem->cmt_speech->device, NULL);
+		modem->cmt_speech = NULL;
+	}
+
 	if (modem->ssi_protocol) {
 		hsi_remove_client(&modem->ssi_protocol->device, NULL);
 		modem->ssi_protocol = NULL;
-- 
2.1.4

Re: [PATCHv3 0/2] N900 Modem Speech Support

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 287 bytes --]

Hi,

On Sat, Mar 21, 2015 at 08:09:15PM +0100, Sebastian Reichel wrote:
> [1] git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-hsi.git branch/cmt-speech-2

This should actually be:

git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-hsi.git branch/cmt-speech-3

-- Sebastian

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Re: [PATCHv3 1/2] HSI: cmt_speech: Add cmt-speech driver

[Aaro Koskinen]

Hi,

On Sat, Mar 21, 2015 at 08:09:16PM +0100, Sebastian Reichel wrote:
> From: Kai Vehmanen <kai.vehmanen@nokia.com>
> 
> Introduces the cmt-speech driver, which implements
> a character device interface for transferring speech
> data frames over HSI/SSI.
> 
> The driver is used to exchange voice/speech data between
> the Nokia N900/N950/N9's modem and its cpu.
> 
> Signed-off-by: Kai Vehmanen <kai.vehmanen@nokia.com>
> Signed-off-by: Carlos Chinea <carlos.chinea@nokia.com>
> Signed-off-by: Joni Lapilainen <joni.lapilainen@gmail.com>

Acked-by: Aaro Koskinen <aaro.koskinen@iki.fi>

A.

Re: [PATCHv3 2/2] HSI: nokia-modem: Add cmt-speech support

[Aaro Koskinen]

Hi,

On Sat, Mar 21, 2015 at 08:09:17PM +0100, Sebastian Reichel wrote:
> Register cmt-speech driver in nokia-modem driver and forward
> hsi channel information.
> 
> Signed-off-by: Sebastian Reichel <sre@kernel.org>

Acked-by: Aaro Koskinen <aaro.koskinen@iki.fi>

A.

Re: [PATCHv3 0/2] N900 Modem Speech Support

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 874 bytes --]

Hi,

On Sat, Mar 21, 2015 at 08:09:15PM +0100, Sebastian Reichel wrote:
> This patchset contains the missing speech data support for the
> Nokia N900 modem.
>
> [...]
>
>   HSI: cmt_speech: Add cmt-speech driver
>   HSI: nokia-modem: Add cmt-speech support
> 
>  drivers/hsi/clients/Kconfig          |   12 +-
>  drivers/hsi/clients/Makefile         |    1 +
>  drivers/hsi/clients/cmt_speech.c     | 1456 ++++++++++++++++++++++++++++++++++
>  drivers/hsi/clients/nokia-modem.c    |   32 +-
>  include/uapi/linux/hsi/Kbuild        |    2 +-
>  include/uapi/linux/hsi/cs-protocol.h |  113 +++
>  6 files changed, 1613 insertions(+), 3 deletions(-)
>  create mode 100644 drivers/hsi/clients/cmt_speech.c
>  create mode 100644 include/uapi/linux/hsi/cs-protocol.h

I added the patches to my linux-hsi.git for-next branch aimed for
4.1.

-- Sebastian


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