[1/2] HSI: add ST-E HSI controller

Message ID 1306340850-31364-1-git-send-email-linus.walleij@stericsson.com
State Changes Requested
Headers show

Commit Message

Linus Walleij May 25, 2011, 4:27 p.m.
From: Pawel Szyszuk <pawel.szyszuk@stericsson.com>

Signed-off-by: Pawel Szyszuk <pawel.szyszuk@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/hsi/controllers/Kconfig   |   10 +
 drivers/hsi/controllers/Makefile  |    1 +
 drivers/hsi/controllers/ste_hsi.c | 1536 +++++++++++++++++++++++++++++++++++++
 3 files changed, 1547 insertions(+), 0 deletions(-)
 create mode 100644 drivers/hsi/controllers/ste_hsi.c

Patch

diff --git a/drivers/hsi/controllers/Kconfig b/drivers/hsi/controllers/Kconfig
index 3efe0f0..76d339e 100644
--- a/drivers/hsi/controllers/Kconfig
+++ b/drivers/hsi/controllers/Kconfig
@@ -3,6 +3,16 @@ 
 #
 comment "HSI controllers"
 
+config STE_HSI
+       tristate "STE HSI controller driver"
+       depends on (ARCH_U8500 || ARCH_NOMADIK) && HSI
+       default n
+       help
+         ST-Ericsson HSI controller.
+         If you say Y here, you will enable the U8500 HSI hardware driver.
+
+         If unsure, say N.
+
 config OMAP_SSI
 	tristate "OMAP SSI hardware driver"
 	depends on ARCH_OMAP && HSI
diff --git a/drivers/hsi/controllers/Makefile b/drivers/hsi/controllers/Makefile
index c4ba2c2..475637a 100644
--- a/drivers/hsi/controllers/Makefile
+++ b/drivers/hsi/controllers/Makefile
@@ -2,4 +2,5 @@ 
 # Makefile for HSI controllers drivers
 #
 
+obj-$(CONFIG_STE_HSI)		+= ste_hsi.o
 obj-$(CONFIG_OMAP_SSI)		+= omap_ssi.o
diff --git a/drivers/hsi/controllers/ste_hsi.c b/drivers/hsi/controllers/ste_hsi.c
new file mode 100644
index 0000000..1a16234
--- /dev/null
+++ b/drivers/hsi/controllers/ste_hsi.c
@@ -0,0 +1,1536 @@ 
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License Terms: GNU General Public License v2
+ * Author: Marcin Mielczarczyk <marcin.mielczarczyk@tieto.com> for ST-Ericsson
+ * Author: Lukasz Baj <lukasz.baj@tieto.com> for ST-Ericsson
+ */
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/hsi/hsi.h>
+
+#ifdef CONFIG_STE_DMA40
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#endif
+
+#include <mach/hsi.h>
+
+/**
+ * struct ste_hsi_controller - Nomadik HSI controller data
+ * @dev: device associated to the controller (HSI controller)
+ * @rx_base: HSI receiver registers base address
+ * @tx_base: HSI transmitter registers base address
+ */
+struct ste_hsi_controller {
+	struct device *dev;
+	struct clk *tx_clk;
+	struct clk *rx_clk;
+	struct clk *ssitx_clk;
+	struct clk *ssirx_clk;
+	struct delayed_work clk_work;
+	unsigned char __iomem *rx_base;
+	unsigned char __iomem *tx_base;
+	int overrun_irq[STE_HSI_MAX_CHANNELS];
+	int ck_refcount;
+	spinlock_t ck_lock;
+	spinlock_t lock;
+	unsigned int use_dma:1;
+	unsigned int ck_on:1;
+	/* physical address of rx and tx controller */
+	dma_addr_t rx_dma_base;
+	dma_addr_t tx_dma_base;
+};
+
+#ifdef CONFIG_STE_DMA40
+struct ste_hsi_channel_dma {
+	struct dma_chan *dma_chan;
+	struct dma_async_tx_descriptor *desc;
+	dma_cookie_t cookie;
+};
+#endif
+
+struct ste_hsi_port {
+	struct device *dev;
+	struct list_head txqueue[STE_HSI_MAX_CHANNELS];
+	struct list_head rxqueue[STE_HSI_MAX_CHANNELS];
+	struct list_head brkqueue;
+	int tx_irq;
+	int rx_irq;
+	int excep_irq;
+	struct tasklet_struct rx_tasklet;
+	struct tasklet_struct tx_tasklet;
+	struct tasklet_struct exception_tasklet;
+	struct tasklet_struct overrun_tasklet;
+	unsigned char channels;
+#ifdef CONFIG_STE_DMA40
+	struct ste_hsi_channel_dma tx_dma[STE_HSI_MAX_CHANNELS];
+	struct ste_hsi_channel_dma rx_dma[STE_HSI_MAX_CHANNELS];
+#endif
+};
+
+#define hsi_to_ste_port(port) (hsi_port_drvdata(port))
+#define hsi_to_ste_controller(con) (hsi_controller_drvdata(con))
+#define client_to_ste_port(cl) (hsi_port_drvdata(hsi_get_port(cl)))
+#define client_to_hsi(cl) \
+	(to_hsi_controller(hsi_get_port(cl)->device.parent))
+#define client_to_ste_controller(cl)  \
+	(hsi_controller_drvdata(client_to_hsi(cl)))
+#define ste_port_to_ste_controller(port) \
+	((struct ste_hsi_controller *)hsi_controller_drvdata(	\
+		to_hsi_controller(port->dev->parent)))
+
+static u32 ste_hsir_periphid[8] = { 0x2C, 0, 0x8, 0x18, 0xD, 0xF0, 0x5, 0xB1 };
+static u32 ste_hsit_periphid[8] = { 0x2B, 0, 0x8, 0x18, 0xD, 0xF0, 0x5, 0xB1 };
+
+/*
+ * linux/amba/bus.h macros can not be used, because 8 bytes are validated:
+ * PERIPHID0..3 and PCELLID0..3 for HSIR and HSIT.
+ */
+static inline int compare_periphid(u32 *id1, u32 *id2, int count)
+{
+	while (count && *id1++ == *id2++)
+		count--;
+
+	return count;
+}
+
+static void ste_hsi_clk_free(struct clk **pclk)
+{
+	if (IS_ERR(*pclk) && *pclk != NULL)
+		clk_put(*pclk);
+	*pclk = NULL;
+}
+
+static void ste_hsi_clks_free(struct ste_hsi_controller *ste_hsi)
+{
+	ste_hsi_clk_free(&ste_hsi->rx_clk);
+	ste_hsi_clk_free(&ste_hsi->tx_clk);
+	ste_hsi_clk_free(&ste_hsi->ssirx_clk);
+	ste_hsi_clk_free(&ste_hsi->ssitx_clk);
+}
+
+static int ste_hsi_clock_enable(struct hsi_controller *hsi)
+{
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+	int err = 0;
+
+	spin_lock_bh(&ste_hsi->ck_lock);
+	if (ste_hsi->ck_refcount++ || ste_hsi->ck_on)
+		goto out;
+
+	err = clk_enable(ste_hsi->ssirx_clk);
+	if (unlikely(err))
+		goto out;
+
+	err = clk_enable(ste_hsi->ssitx_clk);
+	if (unlikely(err))
+		clk_disable(ste_hsi->ssirx_clk);
+
+	err = clk_enable(ste_hsi->rx_clk);
+	if (unlikely(err)) {
+		clk_disable(ste_hsi->ssitx_clk);
+		clk_disable(ste_hsi->ssirx_clk);
+	}
+
+	err = clk_enable(ste_hsi->tx_clk);
+	if (unlikely(err)) {
+		clk_disable(ste_hsi->rx_clk);
+		clk_disable(ste_hsi->ssitx_clk);
+		clk_disable(ste_hsi->ssirx_clk);
+	}
+
+	ste_hsi->ck_on = 1;
+out:
+	if (err)
+		ste_hsi->ck_refcount--;
+
+	spin_unlock_bh(&ste_hsi->ck_lock);
+
+	return err;
+}
+
+static void ste_hsi_delayed_disable_clock(struct work_struct *work)
+{
+	struct ste_hsi_controller *ste_hsi;
+	ste_hsi = container_of(work, struct ste_hsi_controller, clk_work.work);
+
+	spin_lock_bh(&ste_hsi->ck_lock);
+
+	/*
+	 * If clock should not be off (enable clock called in meantime)
+	 * or clock is already off nothing to do
+	 */
+	if (ste_hsi->ck_refcount || !ste_hsi->ck_on)
+		goto out;
+
+	if (readl(ste_hsi->tx_base + STE_HSI_TX_STATE) != STE_HSI_STATE_IDLE ||
+	    readl(ste_hsi->rx_base + STE_HSI_RX_STATE)
+	    != STE_HSI_STATE_IDLE ||
+	    readl(ste_hsi->rx_base + STE_HSI_RX_BUFSTATE) != 0) {
+		/* Try again later */
+		int err = schedule_delayed_work(&ste_hsi->clk_work, HZ);
+		if (err < 0)
+			dev_err(ste_hsi->dev, "Error scheduling work\n");
+		goto out;
+	}
+
+	/* Actual clocks disable */
+	clk_disable(ste_hsi->tx_clk);
+	clk_disable(ste_hsi->rx_clk);
+	clk_disable(ste_hsi->ssitx_clk);
+	clk_disable(ste_hsi->ssirx_clk);
+	ste_hsi->ck_on = 0;
+
+out:
+	spin_unlock_bh(&ste_hsi->ck_lock);
+}
+
+static void ste_hsi_clock_disable(struct hsi_controller *hsi)
+{
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+
+	spin_lock_bh(&ste_hsi->ck_lock);
+
+	/* Sanity check */
+	if (ste_hsi->ck_refcount <= 0)
+		WARN_ON(ste_hsi->ck_refcount <= 0);
+
+	/* Need clock to be disable now? */
+	if (--ste_hsi->ck_refcount)
+		goto out;
+
+	/*
+	 * If receiver or transmitter is in the middle something delay clock off
+	 */
+	if (readl(ste_hsi->tx_base + STE_HSI_TX_STATE) != STE_HSI_STATE_IDLE ||
+	    readl(ste_hsi->rx_base + STE_HSI_RX_STATE)
+	    != STE_HSI_STATE_IDLE ||
+	    readl(ste_hsi->rx_base + STE_HSI_RX_BUFSTATE) != 0) {
+		int err = schedule_delayed_work(&ste_hsi->clk_work, HZ);
+		if (err < 0)
+			dev_err(&hsi->device, "Error scheduling work\n");
+
+		goto out;
+	}
+
+	/* Actual clocks disabled */
+	clk_disable(ste_hsi->tx_clk);
+	clk_disable(ste_hsi->rx_clk);
+	clk_disable(ste_hsi->ssitx_clk);
+	clk_disable(ste_hsi->ssirx_clk);
+	ste_hsi->ck_on = 0;
+
+out:
+	spin_unlock_bh(&ste_hsi->ck_lock);
+}
+
+static int ste_hsi_start_irq(struct hsi_msg *msg)
+{
+	struct hsi_port *port = hsi_get_port(msg->cl);
+	struct hsi_controller *hsi = to_hsi_controller(port->device.parent);
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+	u32 val;
+	int err;
+
+	err = ste_hsi_clock_enable(hsi);
+	if (unlikely(err))
+		return err;
+
+	msg->actual_len = 0;
+	msg->status = HSI_STATUS_PROCEEDING;
+
+	if (msg->ttype == HSI_MSG_WRITE) {
+		val = readl(ste_hsi->tx_base + STE_HSI_TX_WATERMARKIM) |
+		    (1 << msg->channel);
+		writel(val, ste_hsi->tx_base + STE_HSI_TX_WATERMARKIM);
+	} else {
+		val = readl(ste_hsi->rx_base + STE_HSI_RX_WATERMARKIM) |
+		    (1 << msg->channel);
+		writel(val, ste_hsi->rx_base + STE_HSI_RX_WATERMARKIM);
+
+		val = readl(ste_hsi->rx_base + STE_HSI_RX_OVERRUNIM) |
+		    (1 << msg->channel);
+		writel(val, ste_hsi->rx_base + STE_HSI_RX_OVERRUNIM);
+	}
+
+	return 0;
+}
+
+static int ste_hsi_start_transfer(struct ste_hsi_port *ste_port,
+				  struct list_head *queue);
+#ifdef CONFIG_STE_DMA40
+static void ste_hsi_dma_callback(void *dma_async_param)
+{
+	struct hsi_msg *msg = dma_async_param;
+	struct hsi_controller *hsi = client_to_hsi(msg->cl);
+	struct ste_hsi_port *ste_port = client_to_ste_port(msg->cl);
+	struct ste_hsi_controller *ste_hsi = client_to_ste_controller(msg->cl);
+	struct list_head *queue;
+	struct dma_chan *chan;
+	struct ste_hsi_channel_dma *hsi_dma_chan;
+	char *dma_enable_address;
+	enum dma_data_direction direction;
+	u32 dma_mask;
+
+	/* Message finished, remove from list and notify client */
+	spin_lock_bh(&ste_hsi->lock);
+	list_del(&msg->link);
+
+	if (msg->ttype == HSI_MSG_WRITE) {
+		queue = &ste_port->txqueue[msg->channel];
+		direction = DMA_TO_DEVICE;
+		dma_enable_address = ste_hsi->tx_base + STE_HSI_TX_DMAEN;
+		hsi_dma_chan = &ste_port->tx_dma[msg->channel];
+	} else {
+		queue = &ste_port->rxqueue[msg->channel];
+		direction = DMA_FROM_DEVICE;
+		dma_enable_address = ste_hsi->rx_base + STE_HSI_RX_DMAEN;
+		hsi_dma_chan = &ste_port->rx_dma[msg->channel];
+	}
+
+	dma_sync_sg_for_cpu(&hsi->device, msg->sgt.sgl,
+			    msg->sgt.nents, direction);
+	chan = hsi_dma_chan->dma_chan;
+
+	/* disable DMA channel on HSI controller */
+	dma_mask = readl(dma_enable_address);
+	writel(dma_mask & ~(1 << msg->channel), dma_enable_address);
+
+	hsi_dma_chan->desc = NULL;
+
+	dma_unmap_sg(&hsi->device, msg->sgt.sgl, msg->sgt.nents, direction);
+
+	msg->status = HSI_STATUS_COMPLETED;
+	msg->actual_len = sg_dma_len(msg->sgt.sgl);
+
+	spin_unlock_bh(&ste_hsi->lock);
+
+	msg->complete(msg);
+
+	ste_hsi_clock_disable(hsi);
+
+	spin_lock_bh(&ste_hsi->lock);
+	ste_hsi_start_transfer(ste_port, queue);
+	spin_unlock_bh(&ste_hsi->lock);
+}
+
+static void dma_device_control(struct ste_hsi_channel_dma *chan,
+			       enum dma_ctrl_cmd cmd, unsigned long arg)
+{
+	chan->dma_chan->device->device_control(chan->dma_chan, cmd, arg);
+}
+
+static void ste_hsi_terminate_dma_chan(struct ste_hsi_channel_dma *chan)
+{
+	if (chan->desc) {
+		dma_device_control(chan, DMA_TERMINATE_ALL, 0);
+		chan->desc = NULL;
+	}
+	chan->cookie = 0;
+}
+
+static void ste_hsi_terminate_dma(struct ste_hsi_port *ste_port)
+{
+	int i;
+
+	for (i = 0; i < ste_port->channels; ++i) {
+		ste_hsi_terminate_dma_chan(&ste_port->tx_dma[i]);
+		ste_hsi_terminate_dma_chan(&ste_port->rx_dma[i]);
+	}
+}
+
+static int ste_hsi_start_dma(struct hsi_msg *msg)
+{
+	struct hsi_controller *hsi = client_to_hsi(msg->cl);
+	struct ste_hsi_port *ste_port = client_to_ste_port(msg->cl);
+	struct ste_hsi_controller *ste_hsi = client_to_ste_controller(msg->cl);
+	struct dma_async_tx_descriptor *desc;
+	struct dma_chan *chan;
+	struct ste_hsi_channel_dma *hsi_dma_chan;
+	char *dma_enable_address;
+	enum dma_data_direction direction;
+	u32 dma_mask;
+	int err;
+
+	err = ste_hsi_clock_enable(hsi);
+	if (unlikely(err))
+		return err;
+
+	if (msg->ttype == HSI_MSG_WRITE) {
+		direction = DMA_TO_DEVICE;
+		dma_enable_address = ste_hsi->tx_base + STE_HSI_TX_DMAEN;
+		hsi_dma_chan = &ste_port->tx_dma[msg->channel];
+	} else {
+		u32 val;
+		direction = DMA_FROM_DEVICE;
+		dma_enable_address = ste_hsi->rx_base + STE_HSI_RX_DMAEN;
+		hsi_dma_chan = &ste_port->rx_dma[msg->channel];
+
+		/* enable overrun for this channel */
+		val = readl(ste_hsi->rx_base + STE_HSI_RX_OVERRUNIM) |
+		    (1 << msg->channel);
+		writel(val, ste_hsi->rx_base + STE_HSI_RX_OVERRUNIM);
+	}
+
+	chan = hsi_dma_chan->dma_chan;
+
+	if (0 == dma_map_sg(&hsi->device, msg->sgt.sgl, msg->sgt.nents,
+			    direction)) {
+		dev_dbg(&hsi->device, "DMA map SG failed !\n");
+		err = -ENOMEM;
+		goto out;
+	}
+	/* Prepare the scatterlist */
+	desc = chan->device->device_prep_slave_sg(chan,
+						  msg->sgt.sgl,
+						  msg->sgt.nents,
+						  direction,
+						  DMA_PREP_INTERRUPT |
+						  DMA_CTRL_ACK);
+
+	if (!desc) {
+		dma_unmap_sg(&hsi->device, msg->sgt.sgl, msg->sgt.nents,
+			     direction);
+		/* "Complete" DMA (errorpath) */
+		ste_hsi_terminate_dma_chan(hsi_dma_chan);
+		err = -EBUSY;
+		goto out;
+	}
+	desc->callback = ste_hsi_dma_callback;
+	desc->callback_param = msg;
+	hsi_dma_chan->cookie = desc->tx_submit(desc);
+	hsi_dma_chan->desc = desc;
+
+	/* Fire the DMA transaction */
+	chan->device->device_issue_pending(chan);
+
+	/* Enable DMA channel on HSI controller */
+	dma_mask = readl(dma_enable_address);
+	writel(dma_mask | 1 << msg->channel, dma_enable_address);
+
+out:
+	if (unlikely(err))
+		ste_hsi_clock_disable(hsi);
+
+	return err;
+}
+
+static void __init ste_hsi_init_dma(struct ste_hsi_platform_data *data,
+				    struct hsi_controller *hsi)
+{
+	struct hsi_port *port;
+	struct ste_hsi_port *ste_port;
+	struct ste_hsi_controller *ste_hsi = hsi_to_ste_controller(hsi);
+	dma_cap_mask_t mask;
+	int i, ch;
+
+	ste_hsi->use_dma = 1;
+	/* Try to acquire a generic DMA engine slave channel */
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	for (i = 0; i < hsi->num_ports; ++i) {
+		port = &hsi->port[i];
+		ste_port = hsi_port_drvdata(port);
+
+		for (ch = 0; ch < STE_HSI_MAX_CHANNELS; ++ch) {
+			ste_port->tx_dma[ch].dma_chan =
+			    dma_request_channel(mask,
+						data->port_cfg[i].dma_filter,
+						&data->port_cfg[i].
+						dma_tx_cfg[ch]);
+
+			ste_port->rx_dma[ch].dma_chan =
+			    dma_request_channel(mask,
+						data->port_cfg[i].dma_filter,
+						&data->port_cfg[i].
+						dma_rx_cfg[ch]);
+		}
+	}
+}
+
+static int ste_hsi_setup_dma(struct hsi_client *cl)
+{
+	int i;
+	struct hsi_port *port = to_hsi_port(cl->device.parent);
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+	struct hsi_controller *hsi = to_hsi_controller(port->device.parent);
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+	struct dma_slave_config rx_conf = {
+		.src_addr = 0,	/* dynamic data */
+		.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
+		.direction = DMA_FROM_DEVICE,
+		.src_maxburst = 1,
+	};
+	struct dma_slave_config tx_conf = {
+		.dst_addr = 0,	/* dynamic data */
+		.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
+		.direction = DMA_TO_DEVICE,
+		.dst_maxburst = 1,
+	};
+
+	if (!ste_hsi->use_dma)
+		return 0;
+
+	for (i = 0; i < ste_port->channels; ++i) {
+		struct dma_chan *chan;
+
+		chan = ste_port->tx_dma[i].dma_chan;
+		tx_conf.dst_addr = (dma_addr_t) ste_hsi->tx_dma_base +
+		    STE_HSI_TX_BUFFERX + 4 * i;
+		chan->device->device_control(chan,
+					     DMA_SLAVE_CONFIG,
+					     (unsigned long)&tx_conf);
+
+		chan = ste_port->rx_dma[i].dma_chan;
+		rx_conf.src_addr = (dma_addr_t) ste_hsi->rx_dma_base +
+		    STE_HSI_RX_BUFFERX + 4 * i;
+		chan->device->device_control(chan,
+					     DMA_SLAVE_CONFIG,
+					     (unsigned long)&rx_conf);
+	}
+
+	return 0;
+}
+
+#else
+#define ste_hsi_init_dma(data, hsi) do { } while (0)
+#define ste_hsi_start_dma ste_hsi_start_irq
+#define ste_hsi_terminate_dma(ste_port) do { } while (0)
+#define ste_hsi_setup_dma(cl) do { } while (0)
+#endif
+
+static int ste_hsi_start_transfer(struct ste_hsi_port *ste_port,
+				  struct list_head *queue)
+{
+	struct hsi_msg *msg;
+	int err;
+
+	if (list_empty(queue))
+		return 0;
+
+	msg = list_first_entry(queue, struct hsi_msg, link);
+	if (msg->status != HSI_STATUS_QUEUED)
+		return 0;
+
+	msg->actual_len = 0;
+	msg->status = HSI_STATUS_PROCEEDING;
+
+	if (ste_port_to_ste_controller(ste_port)->use_dma)
+		err = ste_hsi_start_dma(msg);
+	else
+		err = ste_hsi_start_irq(msg);
+
+	return err;
+}
+
+static void ste_hsi_receive_data(struct hsi_port *port, unsigned int channel)
+{
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+	struct hsi_controller *hsi = to_hsi_controller(port->device.parent);
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+	struct list_head *queue = &ste_port->rxqueue[channel];
+	struct hsi_msg *msg;
+	char *bufferx;
+	u8 *buf;
+	int span;
+
+	spin_lock_bh(&ste_hsi->lock);
+
+	if (list_empty(queue))
+		goto out;
+
+	msg = list_first_entry(queue, struct hsi_msg, link);
+	if ((!msg->sgt.nents) || (!msg->sgt.sgl->length)) {
+		msg->actual_len = 0;
+		msg->status = HSI_STATUS_PENDING;
+	}
+
+	if (msg->status == HSI_STATUS_PROCEEDING && msg->ttype == HSI_MSG_READ) {
+		unsigned char len;
+		bufferx = ste_hsi->rx_base + STE_HSI_RX_BUFFERX + 4 * channel;
+
+		len = readl(ste_hsi->rx_base + STE_HSI_RX_GAUGEX + 4 * channel);
+		buf = sg_virt(msg->sgt.sgl);
+		buf += msg->actual_len;
+		while (len--) {
+			*(u32 *) buf = readl(bufferx);
+			buf += 4;
+			msg->actual_len += 4;
+			if (msg->actual_len >= msg->sgt.sgl->length) {
+				msg->status = HSI_STATUS_COMPLETED;
+				break;
+			}
+		}
+	}
+
+	/* re-enable interrupt by watermark manipulation */
+	span = readl(ste_hsi->rx_base + STE_HSI_RX_SPANX + 4 * channel);
+	writel(span, ste_hsi->rx_base + STE_HSI_RX_WATERMARKX + 4 * channel);
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_WATERMARKX + 4 * channel);
+
+	/*
+	 * If message was not transmitted completely enable interrupt for
+	 * further work
+	 */
+	if (msg->status == HSI_STATUS_PROCEEDING) {
+		u32 val;
+		val = readl(ste_hsi->rx_base + STE_HSI_RX_WATERMARKIM) |
+		    (1 << channel);
+		writel(val, ste_hsi->rx_base + STE_HSI_RX_WATERMARKIM);
+		goto out;
+	}
+
+	/* Message finished, remove from list and notify client */
+	list_del(&msg->link);
+	spin_unlock_bh(&ste_hsi->lock);
+	msg->complete(msg);
+
+	ste_hsi_clock_disable(hsi);
+
+	spin_lock_bh(&ste_hsi->lock);
+
+	ste_hsi_start_transfer(ste_port, queue);
+out:
+	spin_unlock_bh(&ste_hsi->lock);
+}
+
+static void ste_hsi_transmit_data(struct hsi_port *port, unsigned int channel)
+{
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+	struct hsi_controller *hsi = to_hsi_controller(port->device.parent);
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+	struct list_head *queue = &ste_port->txqueue[channel];
+	struct hsi_msg *msg;
+	u8 *buf;
+	int span;
+
+	if (list_empty(queue))
+		return;
+
+	spin_lock_bh(&ste_hsi->lock);
+	msg = list_first_entry(queue, struct hsi_msg, link);
+	if ((!msg->sgt.nents) || (!msg->sgt.sgl->length)) {
+		msg->actual_len = 0;
+		msg->status = HSI_STATUS_PENDING;
+	}
+
+	if (msg->status == HSI_STATUS_PROCEEDING &&
+		msg->ttype == HSI_MSG_WRITE) {
+		unsigned char free_space;
+
+		free_space = readl(ste_hsi->tx_base +
+				   STE_HSI_TX_GAUGEX + 4 * channel);
+		buf = sg_virt(msg->sgt.sgl);
+		buf += msg->actual_len;
+		while (free_space--) {
+			writel(*(u32 *) buf, ste_hsi->tx_base +
+			       STE_HSI_TX_BUFFERX + 4 * channel);
+			buf += 4;
+			msg->actual_len += 4;
+			if (msg->actual_len >= msg->sgt.sgl->length) {
+				msg->status = HSI_STATUS_COMPLETED;
+				break;
+			}
+		}
+	}
+
+	span = readl(ste_hsi->tx_base + STE_HSI_TX_SPANX + 4 * channel);
+	writel(span, ste_hsi->tx_base + STE_HSI_TX_WATERMARKX + 4 * channel);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_WATERMARKX + 4 * channel);
+
+	if (msg->status == HSI_STATUS_PROCEEDING) {
+		u32 val;
+		val = readl(ste_hsi->tx_base + STE_HSI_TX_WATERMARKIM) |
+		    (1 << channel);
+		writel(val, ste_hsi->tx_base + STE_HSI_TX_WATERMARKIM);
+		goto out;
+	}
+
+	list_del(&msg->link);
+	spin_unlock_bh(&ste_hsi->lock);
+	msg->complete(msg);
+
+	ste_hsi_clock_disable(hsi);
+
+	spin_lock_bh(&ste_hsi->lock);
+	ste_hsi_start_transfer(ste_port, queue);
+out:
+	spin_unlock_bh(&ste_hsi->lock);
+}
+
+static void ste_hsi_rx_tasklet(unsigned long data)
+{
+	struct hsi_port *port = (struct hsi_port *)data;
+	struct hsi_controller *hsi = to_hsi_controller(port->device.parent);
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+	u32 irq_status, irq_mask;
+	unsigned int i;
+
+	irq_status = readl(ste_hsi->rx_base + STE_HSI_RX_WATERMARKIS);
+	if (!irq_status)
+		goto out;
+
+	irq_mask = readl(ste_hsi->rx_base + STE_HSI_RX_WATERMARKIM);
+	writel(irq_mask & ~irq_status,
+	       ste_hsi->rx_base + STE_HSI_RX_WATERMARKIM);
+	writel(irq_mask, ste_hsi->rx_base + STE_HSI_RX_WATERMARKIC);
+
+	for (i = 0; i < STE_HSI_MAX_CHANNELS; ++i) {
+		if (irq_status & (1 << i))
+			ste_hsi_receive_data(port, i);
+	}
+out:
+	enable_irq(ste_port->rx_irq);
+}
+
+static irqreturn_t ste_hsi_rx_isr(int irq, void *data)
+{
+	struct hsi_port *port = data;
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+
+	disable_irq_nosync(irq);
+	tasklet_hi_schedule(&ste_port->rx_tasklet);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ste_hsi_tx_isr(int irq, void *data)
+{
+	struct hsi_port *port = data;
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+
+	disable_irq_nosync(irq);
+	tasklet_hi_schedule(&ste_port->tx_tasklet);
+
+	return IRQ_HANDLED;
+}
+
+static void ste_hsi_tx_tasklet(unsigned long data)
+{
+	struct hsi_port *port = (struct hsi_port *)data;
+	struct hsi_controller *hsi = to_hsi_controller(port->device.parent);
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+	u32 irq_status, irq_mask;
+	unsigned int i;
+
+	irq_status = readl(ste_hsi->tx_base + STE_HSI_TX_WATERMARKIS);
+	if (!irq_status)
+		goto out;
+
+	irq_mask = readl(ste_hsi->tx_base + STE_HSI_TX_WATERMARKIM);
+	writel(irq_mask & ~irq_status,
+	       ste_hsi->tx_base + STE_HSI_TX_WATERMARKIM);
+	writel(irq_mask, ste_hsi->tx_base + STE_HSI_TX_WATERMARKIC);
+
+	for (i = 0; i < STE_HSI_MAX_CHANNELS; ++i) {
+		if (irq_status & (1 << i))
+			ste_hsi_transmit_data(port, i);
+	}
+out:
+	enable_irq(ste_port->tx_irq);
+}
+
+static void ste_hsi_break_complete(struct hsi_port *port,
+				   struct ste_hsi_controller *ste_hsi)
+{
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+	struct hsi_msg *msg, *tmp;
+	u32 mask;
+
+	dev_dbg(port->device.parent, "HWBREAK received\n");
+
+	spin_lock_bh(&ste_hsi->lock);
+
+	mask = readl(ste_hsi->rx_base + STE_HSI_RX_EXCEPIM);
+	writel(mask & ~STE_HSI_EXCEP_BREAK,
+	       ste_hsi->rx_base + STE_HSI_RX_EXCEPIM);
+
+	spin_unlock_bh(&ste_hsi->lock);
+
+	list_for_each_entry_safe(msg, tmp, &ste_port->brkqueue, link) {
+		msg->status = HSI_STATUS_COMPLETED;
+		list_del(&msg->link);
+		msg->complete(msg);
+	}
+}
+
+static void ste_hsi_error(struct hsi_port *port)
+{
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+	struct hsi_msg *msg;
+	unsigned int i;
+
+	for (i = 0; i < ste_port->channels; i++) {
+		if (list_empty(&ste_port->rxqueue[i]))
+			continue;
+		msg = list_first_entry(&ste_port->rxqueue[i], struct hsi_msg,
+				       link);
+		list_del(&msg->link);
+		msg->status = HSI_STATUS_ERROR;
+		msg->complete(msg);
+		/* Now restart queued reads if any */
+		ste_hsi_start_transfer(ste_port, &ste_port->rxqueue[i]);
+	}
+}
+
+static void ste_hsi_exception_tasklet(unsigned long data)
+{
+	struct hsi_port *port = (struct hsi_port *)data;
+	struct hsi_controller *hsi = to_hsi_controller(port->device.parent);
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+	u32 error_status;
+	u32 error_interrupts;
+
+	error_status = readl(ste_hsi->rx_base + STE_HSI_RX_EXCEP);
+	/*
+	 * sometimes interrupt that cause running this tasklet is already
+	 * inactive so base handling of exception on masked interrupt status
+	 * not on exception state register.
+	 */
+	error_interrupts = readl(ste_hsi->rx_base + STE_HSI_RX_EXCEPMIS);
+
+	if (error_interrupts & STE_HSI_EXCEP_BREAK)
+		ste_hsi_break_complete(port, ste_hsi);
+
+	if (error_interrupts & STE_HSI_EXCEP_TIMEOUT)
+		dev_err(&hsi->device, "timeout exception occurred\n");
+	if (error_interrupts & STE_HSI_EXCEP_OVERRUN)
+		dev_err(&hsi->device, "overrun exception occurred\n");
+	if (error_interrupts & STE_HSI_EXCEP_PARITY)
+		dev_err(&hsi->device, "parity exception occurred\n");
+
+	if (error_interrupts & ~STE_HSI_EXCEP_BREAK)
+		ste_hsi_error(port);
+
+	/* Acknowledge exception interrupts */
+	writel(error_status, ste_hsi->rx_base + STE_HSI_RX_ACK);
+
+	enable_irq(ste_port->excep_irq);
+}
+
+static irqreturn_t ste_hsi_exception_isr(int irq, void *data)
+{
+	struct hsi_port *port = data;
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+
+	disable_irq_nosync(irq);
+	tasklet_hi_schedule(&ste_port->exception_tasklet);
+
+	return IRQ_HANDLED;
+}
+
+static void ste_hsi_overrun_tasklet(unsigned long data)
+{
+	struct hsi_controller *hsi = (struct hsi_controller *)data;
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+	struct hsi_port *hsi_port = &hsi->port[0];
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(hsi_port);
+	struct hsi_msg *msg;
+
+	unsigned int channel;
+	u8 rised_overrun;
+	u8 mask;
+	u8 blocked = 0;
+
+	rised_overrun = (u8) readl(ste_hsi->rx_base + STE_HSI_RX_OVERRUNMIS);
+	mask = rised_overrun;
+	for (channel = 0; mask; ++channel, mask >>= 1) {
+		if (!(mask & 1))
+			continue;
+
+		do {
+			/*
+			 * No more messages, block interrupt
+			 */
+			if (list_empty(&ste_port->rxqueue[channel])) {
+				blocked |= 1 << channel;
+				break;
+			}
+			/*
+			 * Complete with error
+			 */
+			msg = list_first_entry(&ste_port->rxqueue[channel],
+					       struct hsi_msg, link);
+			list_del(&msg->link);
+			msg->status = HSI_STATUS_ERROR;
+			msg->complete(msg);
+
+			/*
+			 * Now restart queued reads if any
+			 * If start_transfer fails, try with next message
+			 */
+			if (ste_hsi_start_transfer(ste_port,
+						   &ste_port->rxqueue[channel]))
+				continue;
+		} while (0);
+	}
+
+	/* Overrun acknowledge */
+	writel(rised_overrun, ste_hsi->rx_base + STE_HSI_RX_OVERRUNACK);
+	writel(~blocked & readl(ste_hsi->rx_base + STE_HSI_RX_OVERRUNIM),
+	       ste_hsi->rx_base + STE_HSI_RX_OVERRUNIM);
+
+	/*
+	 * Enable all that should not be blocked
+	 */
+	mask = rised_overrun & ~blocked;
+	for (channel = 0; mask; ++channel, mask >>= 1)
+		enable_irq(ste_hsi->overrun_irq[channel]);
+}
+
+static irqreturn_t ste_hsi_overrun_isr(int irq, void *data)
+{
+	struct hsi_port *port = data;
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+
+	disable_irq_nosync(irq);
+	tasklet_hi_schedule(&ste_port->overrun_tasklet);
+
+	return IRQ_HANDLED;
+}
+
+static void __init ste_hsi_queues_init(struct ste_hsi_port *ste_port)
+{
+	unsigned int ch;
+
+	for (ch = 0; ch < STE_HSI_MAX_CHANNELS; ch++) {
+		INIT_LIST_HEAD(&ste_port->txqueue[ch]);
+		INIT_LIST_HEAD(&ste_port->rxqueue[ch]);
+	}
+	INIT_LIST_HEAD(&ste_port->brkqueue);
+}
+
+static int __init ste_hsi_get_iomem(struct platform_device *pdev,
+				    const char *res_name,
+				    unsigned char __iomem **base,
+				    dma_addr_t *phy)
+{
+	struct resource *mem;
+	struct resource *ioarea;
+
+	mem = platform_get_resource_byname(pdev, IORESOURCE_MEM, res_name);
+	if (!mem) {
+		dev_err(&pdev->dev, "IO memory region missing!\n");
+		return -ENXIO;
+	}
+
+	ioarea = devm_request_mem_region(&pdev->dev, mem->start,
+					 resource_size(mem),
+					 dev_name(&pdev->dev));
+	if (!ioarea) {
+		dev_err(&pdev->dev, "Can't request IO memory region!\n");
+		return -ENXIO;
+	}
+
+	*base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
+	if (!base) {
+		dev_err(&pdev->dev, "%s IO remap failed!\n", mem->name);
+		return -ENXIO;
+	}
+	if (phy)
+		*phy = (dma_addr_t) mem->start;
+
+	return 0;
+}
+
+static int __init ste_hsi_get_irq(struct platform_device *pdev,
+				  const char *res_name,
+				  irqreturn_t(*isr) (int, void *), void *data,
+				  int *irq_number)
+{
+	struct resource *irq;
+	int err;
+
+	irq = platform_get_resource_byname(pdev, IORESOURCE_IRQ, res_name);
+	if (!irq) {
+		dev_err(&pdev->dev, "IO memory region missing!\n");
+		return -ENXIO;
+	}
+
+	err = devm_request_irq(&pdev->dev, irq->start, isr,
+			       IRQF_DISABLED, irq->name, data);
+	if (err)
+		dev_err(&pdev->dev, "%s IRQ request failed!\n", irq->name);
+
+	if (irq_number)
+		*irq_number = irq->start;
+
+	return err;
+}
+
+static void ste_hsi_flush_queue(struct list_head *queue, struct hsi_client *cl)
+{
+	struct list_head *node, *tmp;
+	struct hsi_msg *msg;
+
+	list_for_each_safe(node, tmp, queue) {
+		msg = list_entry(node, struct hsi_msg, link);
+		if ((cl) && (cl != msg->cl))
+			continue;
+		list_del(node);
+
+		if (msg->destructor)
+			msg->destructor(msg);
+		else
+			hsi_free_msg(msg);
+	}
+}
+
+static int ste_hsi_async_break(struct hsi_msg *msg)
+{
+	struct hsi_port *port = hsi_get_port(msg->cl);
+	struct ste_hsi_port *ste_port = hsi_to_ste_port(port);
+	struct hsi_controller *hsi = to_hsi_controller(port->device.parent);
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+	int err;
+
+	err = ste_hsi_clock_enable(hsi);
+	if (unlikely(err))
+		return err;
+
+	if (msg->ttype == HSI_MSG_WRITE) {
+		if (port->tx_cfg.mode != HSI_MODE_FRAME) {
+			err = -EINVAL;
+			goto out;
+		}
+		writel(1, ste_hsi->tx_base + STE_HSI_TX_BREAK);
+		msg->status = HSI_STATUS_COMPLETED;
+		msg->complete(msg);
+	} else {
+		u32 mask;
+		if (port->rx_cfg.mode != HSI_MODE_FRAME) {
+			err = -EINVAL;
+			goto out;
+		}
+		spin_lock_bh(&ste_hsi->lock);
+		msg->status = HSI_STATUS_PROCEEDING;
+		mask = readl(ste_hsi->rx_base + STE_HSI_RX_EXCEPIM);
+		/* Enable break exception on controller */
+		if (!(mask & STE_HSI_EXCEP_BREAK))
+			writel(mask | STE_HSI_EXCEP_BREAK,
+			       ste_hsi->rx_base + STE_HSI_RX_EXCEPIM);
+
+		list_add_tail(&msg->link, &ste_port->brkqueue);
+		spin_unlock_bh(&ste_hsi->lock);
+	}
+
+out:
+	ste_hsi_clock_disable(hsi);
+	return err;
+}
+
+static int ste_hsi_async(struct hsi_msg *msg)
+{
+	struct ste_hsi_controller *ste_hsi;
+	struct ste_hsi_port *ste_port;
+	struct list_head *queue;
+	int err = 0;
+
+	if (unlikely(!msg))
+		return -ENOSYS;
+
+	if (msg->sgt.nents > 1)
+		return -ENOSYS;
+
+	if (unlikely(msg->break_frame))
+		return ste_hsi_async_break(msg);
+
+	ste_port = client_to_ste_port(msg->cl);
+	ste_hsi = client_to_ste_controller(msg->cl);
+
+	if (msg->ttype == HSI_MSG_WRITE) {
+		/* TX transfer */
+		BUG_ON(msg->channel >= ste_port->channels);
+		queue = &ste_port->txqueue[msg->channel];
+	} else {
+		/* RX transfer */
+		queue = &ste_port->rxqueue[msg->channel];
+	}
+
+	spin_lock_bh(&ste_hsi->lock);
+	list_add_tail(&msg->link, queue);
+	msg->status = HSI_STATUS_QUEUED;
+
+	err = ste_hsi_start_transfer(ste_port, queue);
+	if (err)
+		list_del(&msg->link);
+
+	spin_unlock_bh(&ste_hsi->lock);
+
+	return err;
+}
+
+static int ste_hsi_setup(struct hsi_client *cl)
+{
+	struct hsi_port *port = to_hsi_port(cl->device.parent);
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+	struct hsi_controller *hsi = to_hsi_controller(port->device.parent);
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+	int err, i, buffers;
+	u32 div = 0;
+
+	err = ste_hsi_clock_enable(hsi);
+	if (unlikely(err))
+		return err;
+
+	if (cl->tx_cfg.speed) {
+		div = clk_get_rate(ste_hsi->tx_clk) / 1000 / cl->tx_cfg.speed;
+		if (div)
+			--div;
+	}
+
+	port->tx_cfg = cl->tx_cfg;
+	port->rx_cfg = cl->rx_cfg;
+	/* Configure TX */
+	writel(cl->tx_cfg.mode, ste_hsi->tx_base + STE_HSI_TX_MODE);
+	writel(div, ste_hsi->tx_base + STE_HSI_TX_DIVISOR);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_PARITY);
+	/* TODO: Wait for idle here */
+	writel(cl->tx_cfg.channels, ste_hsi->tx_base + STE_HSI_TX_CHANNELS);
+	/* Calculate buffers number per channel */
+	buffers = STE_HSI_MAX_BUFFERS / cl->tx_cfg.channels;
+	for (i = 0; i < cl->tx_cfg.channels; i++) {
+		/* Set 32 bit long frames */
+		writel(31, ste_hsi->tx_base + STE_HSI_TX_FRAMELENX + 4 * i);
+		writel(buffers * i,
+		       ste_hsi->tx_base + STE_HSI_TX_BASEX + 4 * i);
+		writel(buffers - 1,
+		       ste_hsi->tx_base + STE_HSI_TX_SPANX + 4 * i);
+		writel(buffers - 1,
+		       ste_hsi->tx_base + STE_HSI_TX_WATERMARKX + 4 * i);
+		writel(0, ste_hsi->tx_base + STE_HSI_TX_WATERMARKX + 4 * i);
+	}
+
+	/* Configure RX */
+	writel(cl->rx_cfg.mode, ste_hsi->rx_base + STE_HSI_RX_MODE);
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_PARITY);
+	writel(cl->rx_cfg.channels, ste_hsi->rx_base + STE_HSI_RX_CHANNELS);
+	/* Calculate buffers number per channel */
+	buffers = STE_HSI_MAX_BUFFERS / cl->rx_cfg.channels;
+	for (i = 0; i < cl->rx_cfg.channels; i++) {
+		/* Set 32 bit long frames */
+		writel(31, ste_hsi->rx_base + STE_HSI_RX_FRAMELENX + 4 * i);
+		writel(buffers * i,
+		       ste_hsi->rx_base + STE_HSI_RX_BASEX + 4 * i);
+		writel(buffers - 1,
+		       ste_hsi->rx_base + STE_HSI_RX_SPANX + 4 * i);
+		writel(buffers - 1,
+		       ste_hsi->rx_base + STE_HSI_RX_WATERMARKX + 4 * i);
+		writel(0, ste_hsi->rx_base + STE_HSI_RX_WATERMARKX + 4 * i);
+	}
+
+	ste_port->channels = max(cl->tx_cfg.channels, cl->rx_cfg.channels);
+
+	ste_hsi_setup_dma(cl);
+
+	ste_hsi_clock_disable(hsi);
+	return err;
+}
+
+static int ste_hsi_flush(struct hsi_client *cl)
+{
+	struct hsi_port *port = to_hsi_port(cl->device.parent);
+	struct ste_hsi_port *ste_port = hsi_port_drvdata(port);
+	struct hsi_controller *hsi = to_hsi_controller(port->device.parent);
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+	int i;
+
+	ste_hsi_clock_enable(hsi);
+
+	/* Enter sleep mode */
+	writel(STE_HSI_MODE_SLEEP, ste_hsi->rx_base + STE_HSI_RX_MODE);
+
+	/* Disable DMA, and terminate all outstanding jobs */
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_DMAEN);
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_DMAEN);
+	ste_hsi_terminate_dma(ste_port);
+
+	/* Flush all HSIR and HSIT buffers */
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_STATE);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_BUFSTATE);
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_STATE);
+	/*
+	 * BUFSTATE is cleared twice on purpose:
+	 * first time all fifos are cleared
+	 * second time to clear data that was in pipline buffer
+	 * and was transfered to fifos
+	 */
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_BUFSTATE);
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_BUFSTATE);
+
+	/* Flush all errors */
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_EXCEP);
+
+	/* Clear interrupts */
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_WATERMARKIM);
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_WATERMARKIC);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_WATERMARKIM);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_WATERMARKIC);
+	writel(0xFF, ste_hsi->rx_base + STE_HSI_RX_OVERRUNACK);
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_OVERRUNIM);
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_EXCEPIM);
+	writel(0x0F, ste_hsi->rx_base + STE_HSI_RX_ACK);
+
+	/* Dequeue all pending requests */
+	for (i = 0; i < ste_port->channels; i++) {
+		/* Release write clocks */
+		if (!list_empty(&ste_port->txqueue[i]))
+			ste_hsi_clock_disable(hsi);
+		if (!list_empty(&ste_port->rxqueue[i]))
+			ste_hsi_clock_disable(hsi);
+		ste_hsi_flush_queue(&ste_port->txqueue[i], NULL);
+		ste_hsi_flush_queue(&ste_port->rxqueue[i], NULL);
+	}
+	ste_hsi_flush_queue(&ste_port->brkqueue, NULL);
+
+	ste_hsi_clock_disable(hsi);
+
+	return 0;
+}
+
+static int ste_hsi_start_tx(struct hsi_client *cl)
+{
+	return 0;
+}
+
+static int ste_hsi_stop_tx(struct hsi_client *cl)
+{
+	return 0;
+}
+
+static int ste_hsi_release(struct hsi_client *cl)
+{
+	int err;
+	struct ste_hsi_controller *ste_hsi = client_to_ste_controller(cl);
+
+	err = ste_hsi_flush(cl);
+	cancel_delayed_work(&ste_hsi->clk_work);
+
+	return 0;
+}
+
+static int ste_hsi_ports_init(struct hsi_controller *hsi,
+			      struct platform_device *pdev)
+{
+	struct hsi_port *port;
+	struct ste_hsi_port *ste_port;
+	unsigned int i;
+	char irq_name[20];
+	int err;
+
+	for (i = 0; i < hsi->num_ports; i++) {
+		ste_port = devm_kzalloc(&pdev->dev, sizeof *ste_port,
+					GFP_KERNEL);
+		if (!ste_port)
+			return -ENOMEM;
+
+		port = &hsi->port[i];
+		port->async = ste_hsi_async;
+		port->setup = ste_hsi_setup;
+		port->flush = ste_hsi_flush;
+		port->start_tx = ste_hsi_start_tx;
+		port->stop_tx = ste_hsi_stop_tx;
+		port->release = ste_hsi_release;
+		hsi_port_set_drvdata(port, ste_port);
+		ste_port->dev = &port->device;
+
+		sprintf(irq_name, "hsi_rx_irq%d", i);
+		err = ste_hsi_get_irq(pdev, irq_name, ste_hsi_rx_isr, port,
+				      &ste_port->rx_irq);
+		if (err)
+			return err;
+
+		sprintf(irq_name, "hsi_tx_irq%d", i);
+		err = ste_hsi_get_irq(pdev, irq_name, ste_hsi_tx_isr, port,
+				      &ste_port->tx_irq);
+		if (err)
+			return err;
+
+		tasklet_init(&ste_port->rx_tasklet, ste_hsi_rx_tasklet,
+			     (unsigned long)port);
+
+		tasklet_init(&ste_port->tx_tasklet, ste_hsi_tx_tasklet,
+			     (unsigned long)port);
+
+		tasklet_init(&ste_port->exception_tasklet,
+			     ste_hsi_exception_tasklet, (unsigned long)port);
+
+		tasklet_init(&ste_port->overrun_tasklet,
+			     ste_hsi_overrun_tasklet, (unsigned long)port);
+
+		sprintf(irq_name, "hsi_rx_excep%d", i);
+		err = ste_hsi_get_irq(pdev, irq_name, ste_hsi_exception_isr,
+				      port, &ste_port->excep_irq);
+		if (err)
+			return err;
+
+		ste_hsi_queues_init(ste_port);
+	}
+	return 0;
+}
+
+static int __init ste_hsi_hw_init(struct hsi_controller *hsi)
+{
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+	int err;
+
+	err = ste_hsi_clock_enable(hsi);
+	if (unlikely(err))
+		return err;
+
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_BUFSTATE);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_FLUSHBITS);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_PRIORITY);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_BURSTLEN);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_PREAMBLE);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_DATASWAP);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_DMAEN);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_WATERMARKID);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_WATERMARKIC);
+	writel(0, ste_hsi->tx_base + STE_HSI_TX_WATERMARKIM);
+
+	/* 0x23 is reset value per DB8500 Design Spec */
+	writel(0x23, ste_hsi->rx_base + STE_HSI_RX_THRESHOLD);
+
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_BUFSTATE);
+
+	/* Bits 0,1,2 set to 1 to clear exception flags */
+	writel(0x07, ste_hsi->rx_base + STE_HSI_RX_ACK);
+
+	/* Bits 0..7 set to 1 to clear OVERRUN IRQ  */
+	writel(0xFF, ste_hsi->rx_base + STE_HSI_RX_OVERRUNACK);
+
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_DMAEN);
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_WATERMARKIC);
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_WATERMARKIM);
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_OVERRUNIM);
+
+	/* Flush all errors */
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_EXCEP);
+
+	/* 2 is Flush state, no RX exception generated afterwards */
+	writel(2, ste_hsi->rx_base + STE_HSI_RX_STATE);
+
+	writel(0, ste_hsi->rx_base + STE_HSI_RX_EXCEPIM);
+
+	ste_hsi_clock_disable(hsi);
+
+	return err;
+}
+
+static int __init ste_hsi_add_controller(struct hsi_controller *hsi,
+					 struct platform_device *pdev)
+{
+	struct ste_hsi_controller *ste_hsi;
+	char overrun_name[] = "hsi_rx_overrun_chxxx";
+	unsigned char i;
+	int err;
+
+	ste_hsi = kzalloc(sizeof(struct ste_hsi_controller), GFP_KERNEL);
+	if (!ste_hsi) {
+		dev_err(&pdev->dev, "Not enough memory for ste_hsi!\n");
+		return -ENOMEM;
+	}
+
+	spin_lock_init(&ste_hsi->lock);
+	spin_lock_init(&ste_hsi->ck_lock);
+	INIT_DELAYED_WORK(&ste_hsi->clk_work, ste_hsi_delayed_disable_clock);
+
+	hsi->id = pdev->id;
+	hsi->device.parent = &pdev->dev;
+	dev_set_name(&hsi->device, "ste-hsi.%d", hsi->id);
+	ste_hsi->dev = &hsi->device;
+	hsi_controller_set_drvdata(hsi, ste_hsi);
+
+	/* Get and reserve resources for receiver */
+	err = ste_hsi_get_iomem(pdev, "hsi_rx_base", &ste_hsi->rx_base,
+				&ste_hsi->rx_dma_base);
+	if (err)
+		goto err_free_mem;
+	dev_info(&pdev->dev, "hsi_rx_base = %p\n", ste_hsi->rx_base);
+
+	/* Get and reserve resources for transmitter */
+	err = ste_hsi_get_iomem(pdev, "hsi_tx_base", &ste_hsi->tx_base,
+				&ste_hsi->tx_dma_base);
+	if (err)
+		goto err_free_mem;
+	dev_info(&pdev->dev, "hsi_tx_base = %p\n", ste_hsi->tx_base);
+
+	/* Get HSIT HSITXCLK clock */
+	ste_hsi->tx_clk = clk_get(&pdev->dev, "hsit_hsitxclk");
+	if (IS_ERR(ste_hsi->tx_clk)) {
+		dev_err(&hsi->device, "Couldn't get HSIT HSITXCLK clock\n");
+		err = PTR_ERR(ste_hsi->tx_clk);
+		goto err_free_mem;
+	}
+
+	/* Get HSIR HSIRXCLK clock */
+	ste_hsi->rx_clk = clk_get(&pdev->dev, "hsir_hsirxclk");
+	if (IS_ERR(ste_hsi->rx_clk)) {
+		dev_err(&hsi->device, "Couldn't get HSIR HSIRXCLK clock\n");
+		err = PTR_ERR(ste_hsi->rx_clk);
+		goto err_clk_free;
+	}
+
+	/* Get HSIT HCLK clock */
+	ste_hsi->ssitx_clk = clk_get(&pdev->dev, "hsit_hclk");
+	if (IS_ERR(ste_hsi->ssitx_clk)) {
+		dev_err(&hsi->device, "Couldn't get HSIT HCLK clock\n");
+		err = PTR_ERR(ste_hsi->ssitx_clk);
+		goto err_clk_free;
+	}
+
+	/* Get HSIR HCLK clock */
+	ste_hsi->ssirx_clk = clk_get(&pdev->dev, "hsir_hclk");
+	if (IS_ERR(ste_hsi->ssirx_clk)) {
+		dev_err(&hsi->device, "Couldn't get HSIR HCLK clock\n");
+		err = PTR_ERR(ste_hsi->ssirx_clk);
+		goto err_clk_free;
+	}
+
+	err = ste_hsi_clock_enable(hsi);
+	if (unlikely(err))
+		goto err_clk_free;
+
+	/* Check if controller is at specified address */
+	if (compare_periphid(ste_hsir_periphid,
+			     (u32 *) (ste_hsi->rx_base + 0xFE0), 8)) {
+		dev_err(&pdev->dev, "No hsir controller at = %p\n",
+			ste_hsi->rx_base);
+		err = -ENXIO;
+		goto err_clk_free;
+	}
+
+	/* Check if controller is at specified address */
+	if (compare_periphid(ste_hsit_periphid,
+			     (u32 *) (ste_hsi->tx_base + 0xFE0), 8)) {
+		dev_err(&pdev->dev, "No hsit controller at = %p\n",
+			ste_hsi->tx_base);
+		err = -ENXIO;
+		goto err_clk_free;
+	}
+	ste_hsi_clock_disable(hsi);
+
+	err = ste_hsi_hw_init(hsi);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to init HSI controller!\n");
+		goto err_clk_free;
+	}
+
+	for (i = 0; i < STE_HSI_MAX_CHANNELS; i++) {
+		sprintf(overrun_name, "hsi_rx_overrun_ch%d", i);
+		err = ste_hsi_get_irq(pdev, overrun_name, ste_hsi_overrun_isr,
+				      hsi, &ste_hsi->overrun_irq[i]);
+		if (err)
+			goto err_clk_free;
+	}
+
+	err = ste_hsi_ports_init(hsi, pdev);
+	if (err)
+		goto err_clk_free;
+
+	err = hsi_register_controller(hsi);
+	if (err)
+		goto err_clk_free;
+
+	return 0;
+
+err_clk_free:
+	ste_hsi_clks_free(ste_hsi);
+err_free_mem:
+	kfree(ste_hsi);
+	return err;
+}
+
+static int ste_hsi_remove_controller(struct hsi_controller *hsi,
+				     struct platform_device *pdev)
+{
+	struct ste_hsi_controller *ste_hsi = hsi_controller_drvdata(hsi);
+
+	ste_hsi_clks_free(ste_hsi);
+	hsi_unregister_controller(hsi);
+
+	return 0;
+}
+
+static int __init ste_hsi_probe(struct platform_device *pdev)
+{
+	struct hsi_controller *hsi;
+	struct ste_hsi_platform_data *pdata = pdev->dev.platform_data;
+	int err;
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "No HSI platform data!\n");
+		return -EINVAL;
+	}
+
+	hsi = hsi_alloc_controller(pdata->num_ports, GFP_KERNEL);
+	if (!hsi) {
+		dev_err(&pdev->dev, "No memory to allocate HSI controller!\n");
+		return -ENOMEM;
+	}
+	platform_set_drvdata(pdev, hsi);
+
+	err = ste_hsi_add_controller(hsi, pdev);
+	if (err < 0) {
+		dev_err(&pdev->dev, "Can't add HSI controller!\n");
+		goto err_free_controller;
+	}
+
+	if (pdata->use_dma)
+		ste_hsi_init_dma(pdata, hsi);
+
+	return 0;
+
+err_free_controller:
+	platform_set_drvdata(pdev, NULL);
+	hsi_free_controller(hsi);
+
+	return err;
+}
+
+static int __exit ste_hsi_remove(struct platform_device *pdev)
+{
+	struct hsi_controller *hsi = platform_get_drvdata(pdev);
+
+	ste_hsi_remove_controller(hsi, pdev);
+	hsi_free_controller(hsi);
+
+	return 0;
+}
+
+static struct platform_driver ste_hsi_driver __refdata = {
+	.driver = {
+		   .name = "ste_hsi",
+		   .owner = THIS_MODULE,
+		   },
+	.remove = __exit_p(ste_hsi_remove),
+};
+
+static int __init ste_hsi_init(void)
+{
+	return platform_driver_probe(&ste_hsi_driver, ste_hsi_probe);
+}
+
+module_init(ste_hsi_init)
+
+static void __exit ste_hsi_exit(void)
+{
+	platform_driver_unregister(&ste_hsi_driver);
+}
+
+module_exit(ste_hsi_exit)
+
+    MODULE_AUTHOR("Lukasz Baj <lukasz.baj@tieto.com");
+    MODULE_DESCRIPTION("STE HSI driver.");
+    MODULE_LICENSE("GPL");