Re: [PATCH 2/4 v4] i.MX31: Image Processing Unit DMA and IRQ drivers

diff --git a/drivers/mfd/ipu/ipu_idmac.c b/drivers/mfd/ipu/ipu_idmac.c
new file mode 100644
index 0000000..85319f8
--- /dev/null
+++ b/drivers/mfd/ipu/ipu_idmac.c

@@ -0,0 +1,1662 @@
+/*
+ * Copyright (C) 2008
+ * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
+ *
+ * Copyright (C) 2005-2007 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/list.h>
+#include <linux/clk.h>
+#include <linux/vmalloc.h>
+#include <linux/string.h>
+#include <linux/interrupt.h>
+
+#include <mach/ipu.h>
+
+#include <asm/io.h>

+
+#include "ipu_intern.h"
+
+#define FS_VF_IN_VALID	0x00000002
+#define FS_ENC_IN_VALID	0x00000001
+
+/*
+ * There can be only one, we could allocate it dynamically, but then we'd have
+ * to add an extra parameter to some functions, and use something as ugly as
+ *	struct ipu *ipu = to_ipu(to_idmac(ichan->dma_chan.device));

+ * in the ISR
+ */
+static struct ipu ipu_data;
+
+#define to_ipu(id) container_of(id, struct ipu, idmac)
+
+static u32 __idmac_read_icreg(struct ipu *ipu, unsigned long reg)
+{
+	return __raw_readl(ipu->reg_ic + reg);
+}
+
+#define idmac_read_icreg(ipu, reg) __idmac_read_icreg(ipu, reg - IC_CONF)
+
+static void __idmac_write_icreg(struct ipu *ipu, u32 value, unsigned long reg)
+{
+	__raw_writel(value, ipu->reg_ic + reg);
+}
+
+#define idmac_write_icreg(ipu, v, reg) __idmac_write_icreg(ipu, v, reg - IC_CONF)
+
+static u32 idmac_read_ipureg(struct ipu *ipu, unsigned long reg)
+{
+	return __raw_readl(ipu->reg_ipu + reg);
+}
+
+static void idmac_write_ipureg(struct ipu *ipu, u32 value, unsigned long reg)
+{
+	__raw_writel(value, ipu->reg_ipu + reg);
+}
+
+/*****************************************************************************
+ * IPU / IC common functions
+ */
+static void dump_idmac_reg(struct ipu *ipu)
+{
+	dev_dbg(ipu->dev, "IDMAC_CONF 0x%x, IC_CONF 0x%x, IDMAC_CHA_EN 0x%x, "
+		"IDMAC_CHA_PRI 0x%x, IDMAC_CHA_BUSY 0x%x\n",
+		idmac_read_icreg(ipu, IDMAC_CONF),
+		idmac_read_icreg(ipu, IC_CONF),
+		idmac_read_icreg(ipu, IDMAC_CHA_EN),
+		idmac_read_icreg(ipu, IDMAC_CHA_PRI),
+		idmac_read_icreg(ipu, IDMAC_CHA_BUSY));
+	dev_dbg(ipu->dev, "BUF0_RDY 0x%x, BUF1_RDY 0x%x, CUR_BUF 0x%x, "
+		"DB_MODE 0x%x, TASKS_STAT 0x%x\n",
+		idmac_read_ipureg(ipu, IPU_CHA_BUF0_RDY),
+		idmac_read_ipureg(ipu, IPU_CHA_BUF1_RDY),
+		idmac_read_ipureg(ipu, IPU_CHA_CUR_BUF),
+		idmac_read_ipureg(ipu, IPU_CHA_DB_MODE_SEL),
+		idmac_read_ipureg(ipu, IPU_TASKS_STAT));
+}
+
+static uint32_t bytes_per_pixel(enum pixel_fmt fmt)
+{
+	switch (fmt) {
+	case IPU_PIX_FMT_GENERIC:	/* generic data */
+	case IPU_PIX_FMT_RGB332:
+	case IPU_PIX_FMT_YUV420P:
+	case IPU_PIX_FMT_YUV422P:
+	default:
+		return 1;
+	case IPU_PIX_FMT_RGB565:
+	case IPU_PIX_FMT_YUYV:
+	case IPU_PIX_FMT_UYVY:
+		return 2;
+	case IPU_PIX_FMT_BGR24:
+	case IPU_PIX_FMT_RGB24:
+		return 3;
+	case IPU_PIX_FMT_GENERIC_32:	/* generic data */
+	case IPU_PIX_FMT_BGR32:
+	case IPU_PIX_FMT_RGB32:
+	case IPU_PIX_FMT_ABGR32:
+		return 4;
+	}
+}
+
+/* Enable / disable direct write to memory by the Camera Sensor Interface */
+static void _ipu_ic_enable_task(struct ipu *ipu, enum ipu_channel channel)
+{
+	uint32_t ic_conf, mask;
+
+	switch (channel) {
+	case IDMAC_IC_0:
+		mask = IC_CONF_PRPENC_EN;
+		break;
+	case IDMAC_IC_7:
+		mask = IC_CONF_RWS_EN | IC_CONF_PRPENC_EN;
+		break;
+	default:
+		return;
+	}
+	ic_conf = idmac_read_icreg(ipu, IC_CONF) | mask;
+	idmac_write_icreg(ipu, ic_conf, IC_CONF);
+}
+
+static void _ipu_ic_disable_task(struct ipu *ipu, enum ipu_channel channel)
+{
+	uint32_t ic_conf, mask;
+
+	switch (channel) {
+	case IDMAC_IC_0:
+		mask = IC_CONF_PRPENC_EN;
+		break;
+	case IDMAC_IC_7:
+		mask = IC_CONF_RWS_EN | IC_CONF_PRPENC_EN;
+		break;
+	default:
+		return;
+	}
+	ic_conf = idmac_read_icreg(ipu, IC_CONF) & ~mask;
+	idmac_write_icreg(ipu, ic_conf, IC_CONF);
+}
+
+static uint32_t _ipu_channel_status(struct ipu *ipu, enum ipu_channel channel)
+{
+	uint32_t stat = TASK_STAT_IDLE;
+	uint32_t task_stat_reg = idmac_read_ipureg(ipu, IPU_TASKS_STAT);
+
+	switch (channel) {
+	case IDMAC_IC_7:
+		stat = (task_stat_reg & TSTAT_CSI2MEM_MASK) >>
+			TSTAT_CSI2MEM_OFFSET;
+		break;
+	case IDMAC_IC_0:
+	case IDMAC_SDC_0:
+	case IDMAC_SDC_1:
+	default:
+		break;
+	}
+	return stat;
+}
+
+static void _ipu_ch_param_set_size(uint32_t *params,
+				   uint32_t pixel_fmt, uint16_t width,
+				   uint16_t height, uint16_t stride)
+{
+	uint32_t u_offset = 0;
+	uint32_t v_offset = 0;
+
+	params[3] = (uint32_t)((width - 1) << 12) |
+		((uint32_t)(height - 1) << 24);
+	params[4] = (uint32_t)(height - 1) >> 8;
+	params[7] = (uint32_t)(stride - 1) << 3;
+
+	switch (pixel_fmt) {
+	case IPU_PIX_FMT_GENERIC:
+		/*Represents 8-bit Generic data */
+		params[7] |= 3 | (7UL << (81 - 64)) | (31L << (89 - 64));	/* BPP & PFS */
+		params[8] = 2;				/* SAT = use 32-bit access */
+		break;
+	case IPU_PIX_FMT_GENERIC_32:
+		/*Represents 32-bit Generic data */
+		params[7] |= (7UL << (81 - 64)) | (7L << (89 - 64));		/* BPP & PFS */
+		params[8] = 2;				/* SAT = use 32-bit access */
+		break;
+	case IPU_PIX_FMT_RGB565:
+		params[7] |= 2L | (4UL << (81 - 64)) | (7L << (89 - 64));	/* BPP & PFS */
+		params[8] = 2 |				/* SAT = 32-bit access */
+		    (0UL << (99 - 96)) |		/* Red bit offset */
+		    (5UL << (104 - 96)) |		/* Green bit offset */
+		    (11UL << (109 - 96)) |		/* Blue bit offset */
+		    (16UL << (114 - 96)) |		/* Alpha bit offset */
+		    (4UL << (119 - 96)) |		/* Red bit width - 1 */
+		    (5UL << (122 - 96)) |		/* Green bit width - 1 */
+		    (4UL << (125 - 96));		/* Blue bit width - 1 */
+		break;
+	case IPU_PIX_FMT_BGR24:
+		params[7] |= 1 | (4UL << (81 - 64)) | (7L << (89 - 64));	/* 24 BPP & RGB PFS */
+		params[8] = 2 |				/* SAT = 32-bit access */
+		    (8UL << (104 - 96)) |		/* Green bit offset */
+		    (16UL << (109 - 96)) |		/* Blue bit offset */
+		    (24UL << (114 - 96)) |		/* Alpha bit offset */
+		    (7UL << (119 - 96)) |		/* Red bit width - 1 */
+		    (7UL << (122 - 96)) |		/* Green bit width - 1 */
+		    (uint32_t) (7UL << (125 - 96));	/* Blue bit width - 1 */
+		break;
+	case IPU_PIX_FMT_RGB24:
+		params[7] |= 1 | (4UL << (81 - 64)) | (7L << (89 - 64));	/* 24 BPP & RGB PFS */
+		params[8] = 2 |				/* SAT = 32-bit access */
+		    (16UL << (99 - 96)) |		/* Red bit offset */
+		    (8UL << (104 - 96)) |		/* Green bit offset */
+		    (0UL << (109 - 96)) |		/* Blue bit offset */
+		    (24UL << (114 - 96)) |		/* Alpha bit offset */
+		    (7UL << (119 - 96)) |		/* Red bit width - 1 */
+		    (7UL << (122 - 96)) |		/* Green bit width - 1 */
+		    (uint32_t) (7UL << (125 - 96));	/* Blue bit width - 1 */
+		break;
+	case IPU_PIX_FMT_BGRA32:
+	case IPU_PIX_FMT_BGR32:
+		params[7] |= 0 | (4UL << (81 - 64)) | (7 << (89 - 64));		/* BPP & PFS */
+		params[8] = 2 |				/* SAT = 32-bit access */
+		    (8UL << (99 - 96)) |		/* Red bit offset */
+		    (16UL << (104 - 96)) |		/* Green bit offset */
+		    (24UL << (109 - 96)) |		/* Blue bit offset */
+		    (0UL << (114 - 96)) |		/* Alpha bit offset */
+		    (7UL << (119 - 96)) |		/* Red bit width - 1 */
+		    (7UL << (122 - 96)) |		/* Green bit width - 1 */
+		    (uint32_t) (7UL << (125 - 96));	/* Blue bit width - 1 */
+		params[9] = 7;				/* Alpha bit width - 1 */
+		break;
+	case IPU_PIX_FMT_RGBA32:
+	case IPU_PIX_FMT_RGB32:
+		params[7] |= 0 | (4UL << (81 - 64)) | (7 << (89 - 64));
+		params[8] = 2 |				/* SAT = 32-bit access */
+		    (24UL << (99 - 96)) |		/* Red bit offset */
+		    (16UL << (104 - 96)) |		/* Green bit offset     */
+		    (8UL << (109 - 96)) |		/* Blue bit offset */
+		    (0UL << (114 - 96)) |		/* Alpha bit offset     */
+		    (7UL << (119 - 96)) |		/* Red bit width - 1 */
+		    (7UL << (122 - 96)) |		/* Green bit width - 1 */
+		    (uint32_t) (7UL << (125 - 96));	/* Blue bit width - 1 */
+		params[9] = 7;				/* Alpha bit width - 1 */
+		break;
+	case IPU_PIX_FMT_ABGR32:
+		params[7] |= 0 | (4UL << (81 - 64)) | (7 << (89 - 64));
+		params[8] = 2 |				/* SAT = 32-bit access */
+		    (0UL << (99 - 96)) |		/* Alpha bit offset */
+		    (8UL << (104 - 96)) |		/* Blue bit offset */
+		    (16UL << (109 - 96)) |		/* Green bit offset */
+		    (24UL << (114 - 96)) |		/* Red bit offset */
+		    (7UL << (119 - 96)) |		/* Alpha bit width - 1 */
+		    (7UL << (122 - 96)) |		/* Blue bit width - 1 */
+		    (uint32_t) (7UL << (125 - 96));	/* Green bit width - 1 */
+		params[9] = 7;				/* Red bit width - 1 */
+		break;
+	case IPU_PIX_FMT_UYVY:
+		params[7] |= 2 | (6UL << 17) | (7 << (89 - 64));
+		params[8] = 2;				/* SAT = 32-bit access */
+		break;
+	case IPU_PIX_FMT_YUV420P2:
+	case IPU_PIX_FMT_YUV420P:
+		params[7] |= 3 | (3UL << 17) | (7 << (89 - 64));
+		params[8] = 2;				/* SAT = 32-bit access */
+		u_offset = stride * height;
+		v_offset = u_offset + u_offset / 4;
+		break;
+	case IPU_PIX_FMT_YVU422P:
+		params[7] |= 3 | (2UL << 17) | (7 << (89 - 64));
+		params[8] = 2;				/* SAT = 32-bit access */
+		v_offset = stride * height;
+		u_offset = v_offset + v_offset / 2;
+		break;
+	case IPU_PIX_FMT_YUV422P:
+		params[7] |= 3 | (2UL << 17) | (7 << (89 - 64));
+		params[8] = 2;				/* SAT = 32-bit access */
+		u_offset = stride * height;
+		v_offset = u_offset + u_offset / 2;
+		break;
+	default:
+		dev_err(ipu_data.dev, "mxc ipu: unimplemented pixel format\n");
+		break;
+	}
+
+	params[1] = (1UL << (46 - 32)) | (u_offset << (53 - 32));
+	params[2] = u_offset >> (64 - 53);
+	params[2] |= v_offset << (79 - 64);
+	params[3] |= v_offset >> (96 - 79);
+}

+
+static void _ipu_ch_param_set_burst_size(uint32_t *params,
+					 uint16_t burst_pixels)
+{
+	params[7] &= ~(0x3FL << (89 - 64));
+	params[7] |= (uint32_t)(burst_pixels - 1) << (89 - 64);
+};
+
+static void _ipu_ch_param_set_buffer(uint32_t *params,
+				     dma_addr_t buf0, dma_addr_t buf1)
+{
+	params[5] = buf0;
+	params[6] = buf1;
+};
+
+static void _ipu_ch_param_set_rotation(uint32_t *params,
+				       enum ipu_rotate_mode rot)
+{
+	params[7] |= (uint32_t)rot << (84 - 64);
+};
+
+static void _ipu_write_param_mem(uint32_t addr, uint32_t *data,
+				 uint32_t numWords)
+{
+	for (; numWords > 0; numWords--) {

+		dev_dbg(ipu_data.dev,
+			"write param mem - addr = 0x%08X, data = 0x%08X\n",
+			addr, *data);
+		idmac_write_ipureg(&ipu_data, addr, IPU_IMA_ADDR);
+		idmac_write_ipureg(&ipu_data, *data++, IPU_IMA_DATA);
+		addr++;
+		if ((addr & 0x7) == 5) {
+			addr &= ~0x7;	/* set to word 0 */
+			addr += 8;	/* increment to next row */
+		}
+	}
+}
+
+static bool _calc_resize_coeffs(uint32_t in_size, uint32_t out_size,
+				uint32_t *resize_coeff,
+				uint32_t *downsize_coeff)
+{
+	uint32_t temp_size;
+	uint32_t temp_downsize;
+
+	/* Cannot downsize more than 8:1 */
+	if ((out_size << 3) < in_size)
+		return false;

+
+	/* compute downsizing coefficient */
+	temp_downsize = 0;
+	temp_size = in_size;
+	while ((temp_size >= out_size * 2) && (temp_downsize < 2)) {
+		temp_size >>= 1;
+		temp_downsize++;
+	}
+	*downsize_coeff = temp_downsize;
+
+	/*
+	 * compute resizing coefficient using the following formula:
+	 * resize_coeff = M*(SI -1)/(SO - 1)
+	 * where M = 2^13, SI - input size, SO - output size
+	 */
+	*resize_coeff = (8192L * (temp_size - 1)) / (out_size - 1);
+	if (*resize_coeff >= 16384L) {
+		dev_err(ipu_data.dev, "Warning! Overflow on resize coeff.\n");
+		*resize_coeff = 0x3FFF;
+	}
+
+	dev_dbg(ipu_data.dev, "resizing from %u -> %u pixels, "
+		"downsize=%u, resize=%u.%lu (reg=%u)\n", in_size, out_size,
+		*downsize_coeff, *resize_coeff >= 8192L ? 1 : 0,
+		((*resize_coeff & 0x1FFF) * 10000L) / 8192L, *resize_coeff);
+
+	return true;
+}
+
+static enum ipu_color_space format_to_colorspace(enum pixel_fmt fmt)
+{
+	switch (fmt) {
+	case IPU_PIX_FMT_RGB565:
+	case IPU_PIX_FMT_BGR24:
+	case IPU_PIX_FMT_RGB24:
+	case IPU_PIX_FMT_BGR32:
+	case IPU_PIX_FMT_RGB32:
+		return IPU_COLORSPACE_RGB;
+	default:
+		return IPU_COLORSPACE_YCBCR;
+	}
+}
+
+static int _ipu_ic_init_prpenc(struct ipu *ipu,
+			       union ipu_channel_param *params, bool src_is_csi)
+{
+	uint32_t reg, ic_conf;
+	uint32_t downsize_coeff, resize_coeff;
+	enum ipu_color_space in_fmt, out_fmt;
+
+	/* Setup vertical resizing */
+	_calc_resize_coeffs(params->video.in_height,
+			    params->video.out_height,
+			    &resize_coeff, &downsize_coeff);
+	reg = (downsize_coeff << 30) | (resize_coeff << 16);
+
+	/* Setup horizontal resizing */
+	_calc_resize_coeffs(params->video.in_width,
+			    params->video.out_width,
+			    &resize_coeff, &downsize_coeff);
+	reg |= (downsize_coeff << 14) | resize_coeff;
+
+	/* Setup color space conversion */
+	in_fmt = format_to_colorspace(params->video.in_pixel_fmt);
+	out_fmt = format_to_colorspace(params->video.out_pixel_fmt);
+
+	/*
+	 * Colourspace conversion unsupported yet - see _init_csc() in
+	 * Freescale sources
+	 */
+	if (in_fmt != out_fmt) {
+		dev_err(ipu->dev, "Colourspace conversion unsupported!\n");
+		return -EOPNOTSUPP;
+	}
+
+	idmac_write_icreg(ipu, reg, IC_PRP_ENC_RSC);
+
+	ic_conf = idmac_read_icreg(ipu, IC_CONF);
+
+	if (src_is_csi)
+		ic_conf &= ~IC_CONF_RWS_EN;
+	else
+		ic_conf |= IC_CONF_RWS_EN;
+
+	idmac_write_icreg(ipu, ic_conf, IC_CONF);
+
+	return 0;
+}
+
+static uint32_t dma_param_addr(uint32_t dma_ch)
+{
+	/* Channel Parameter Memory */
+	return 0x10000 | (dma_ch << 4);
+};
+
+static void _ipu_channel_set_priority(struct ipu *ipu, enum ipu_channel channel, bool prio)
+{
+	u32 reg = idmac_read_icreg(ipu, IDMAC_CHA_PRI);
+
+	if (prio)
+		reg |= 1UL << channel;
+	else
+		reg &= ~(1UL << channel);
+
+	idmac_write_icreg(ipu, reg, IDMAC_CHA_PRI);
+
+	dump_idmac_reg(ipu);
+}
+
+static uint32_t _ipu_channel_conf_check(struct ipu *ipu, enum ipu_channel channel)
+{
+	uint32_t ipu_conf;
+
+	ipu_conf = idmac_read_ipureg(ipu, IPU_CONF);
+	if (WARN(!ipu_conf, "Uninitialized IPU_CONF!\n"))
+		/* Should not happen. Error out here. */
+		clk_enable(ipu->ipu_clk);

+
+	if (ipu->channel_init_mask & (1L << channel))
+		dev_err(ipu->dev, "Warning: channel already initialized %d\n",
+			channel);
+
+	return ipu_conf;
+}

+
+static uint32_t _ipu_channel_conf_mask(enum ipu_channel channel)
+{
+	uint32_t mask;
+
+	switch (channel) {
+	case IDMAC_IC_0:
+		mask = IPU_CONF_CSI_EN | IPU_CONF_IC_EN;
+		break;
+	case IDMAC_IC_7:
+		mask = IPU_CONF_CSI_EN | IPU_CONF_IC_EN;
+		break;

+	case IDMAC_SDC_0:
+		mask = IPU_CONF_SDC_EN | IPU_CONF_DI_EN;
+		break;
+	case IDMAC_SDC_1:
+		mask = IPU_CONF_SDC_EN | IPU_CONF_DI_EN;
+		break;

+	default:
+		mask = 0;
+		break;
+	}
+
+	return mask;
+}
+
+/**
+ * Enable an IPU channel.
+ *
+ * @param       channel         Input parameter for the logical channel ID.
+ *
+ * @return      Returns 0 on success or negative error code on failure.
+ */
+static int ipu_enable_channel(struct idmac *idmac, struct idmac_channel *ichan)
+{
+	struct ipu *ipu = to_ipu(idmac);
+	enum ipu_channel channel = ichan->dma_chan.chan_id;
+	uint32_t reg;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ipu->lock, flags);
+
+	/* Reset to buffer 0 */
+	idmac_write_ipureg(ipu, 1UL << channel, IPU_CHA_CUR_BUF);
+	ichan->active_buffer = 0;
+	ichan->status = IPU_CHANNEL_ENABLED;
+
+	switch (channel) {
+	case IDMAC_SDC_0:
+	case IDMAC_SDC_1:
+	case IDMAC_IC_7:
+		_ipu_channel_set_priority(ipu, channel, true);
+	default:
+		break;
+	}
+
+	reg = idmac_read_icreg(ipu, IDMAC_CHA_EN);
+
+	idmac_write_icreg(ipu, reg | (1UL << channel), IDMAC_CHA_EN);
+
+	_ipu_ic_enable_task(ipu, channel);
+
+	spin_unlock_irqrestore(&ipu->lock, flags);
+	return 0;
+}
+
+/**
+ * Initialize a buffer for logical IPU channel.
+ *
+ * @param       channel         Input parameter for the logical channel ID.
+ *
+ * @param       pixel_fmt       Input parameter for pixel format of buffer. Pixel
+ *                              format is a FOURCC ASCII code.
+ *
+ * @param       width           Input parameter for width of buffer in pixels.
+ *
+ * @param       height          Input parameter for height of buffer in pixels.
+ *
+ * @param       stride          Input parameter for stride length of buffer
+ *                              in pixels.
+ *
+ * @param       rot_mode        Input parameter for rotation setting of buffer.
+ *                              A rotation setting other than \b IPU_ROTATE_VERT_FLIP
+ *                              should only be used for input buffers of rotation
+ *                              channels.
+ *
+ * @param       phyaddr_0       Input parameter buffer 0 physical address.
+ *
+ * @param       phyaddr_1       Input parameter buffer 1 physical address.
+ *                              Setting this to a value other than NULL enables
+ *                              double buffering mode.
+ *
+ * @return      Returns 0 on success or negative error code on failure.
+ */
+static int ipu_init_channel_buffer(struct idmac_channel *ichan,
+				   enum pixel_fmt pixel_fmt,
+				   uint16_t width, uint16_t height,
+				   uint32_t stride,
+				   enum ipu_rotate_mode rot_mode,
+				   dma_addr_t phyaddr_0, dma_addr_t phyaddr_1)
+{
+	enum ipu_channel channel = ichan->dma_chan.chan_id;
+	struct idmac *idmac = to_idmac(ichan->dma_chan.device);
+	struct ipu *ipu = to_ipu(idmac);
+	uint32_t params[10] = {0};
+	unsigned long flags;
+	uint32_t reg;
+	uint32_t stride_bytes;
+
+	stride_bytes = stride * bytes_per_pixel(pixel_fmt);
+
+	if (stride_bytes % 4) {
+		dev_err(ipu->dev,
+			"Stride length must be 32-bit aligned, stride = %d, bytes = %d\n",
+			stride, stride_bytes);
+		return -EINVAL;
+	}
+	/* IC channel's stride must be a multiple of 8 pixels */
+	if ((channel <= 13) && (stride % 8)) {
+		dev_err(ipu->dev, "Stride must be 8 pixel multiple\n");
+		return -EINVAL;
+	}
+	/* Build parameter memory data for DMA channel */
+	_ipu_ch_param_set_size(params, pixel_fmt, width, height, stride_bytes);
+	_ipu_ch_param_set_buffer(params, phyaddr_0, phyaddr_1);
+	_ipu_ch_param_set_rotation(params, rot_mode);
+	/* Some channels (rotation) have restriction on burst length */
+	switch (channel) {
+	case IDMAC_IC_7:	/* Hangs with burst 8, 16, other values
+				   invalid - Table 44-30 */
+/*
+		_ipu_ch_param_set_burst_size(params, 8);
+ */
+		break;
+	case IDMAC_SDC_0:
+	case IDMAC_SDC_1:
+		/* In original code only IPU_PIX_FMT_RGB565 was setting burst */
+		_ipu_ch_param_set_burst_size(params, 16);
+		break;
+	case IDMAC_IC_0:
+	default:
+		break;
+	}
+
+	/* In fact, channel is not running yet, so, don't have to protect */
+	spin_lock_irqsave(&ipu->lock, flags);

+
+	_ipu_write_param_mem(dma_param_addr(channel), params, 10);
+
+	reg = idmac_read_ipureg(ipu, IPU_CHA_DB_MODE_SEL);
+
+	if (phyaddr_1)
+		reg |= 1UL << channel;
+	else
+		reg &= ~(1UL << channel);
+
+	idmac_write_ipureg(ipu, reg, IPU_CHA_DB_MODE_SEL);
+
+	ichan->status = IPU_CHANNEL_READY;
+
+	spin_unlock_irqrestore(ipu->lock, flags);
+
+	return 0;
+}
+
+/**
+ * Set a channel's buffer as ready.
+ *
+ * @param       channel         Input parameter for the logical channel ID.
+ *
+ * @param       type            Input parameter which buffer to initialize.
+ *
+ * @param       bufNum          Input parameter for which buffer number set to

+ *                              ready state.
+ *
+ * @return      Returns 0 on success or negative error code on failure.
+ */
+static void ipu_select_buffer(enum ipu_channel channel, int buffer_n)
+{
+	/* No locking - this is a write-one-to-set register, cleared by IPU */

+	if (buffer_n == 0)
+		/* Mark buffer 0 as ready. */
+		idmac_write_ipureg(&ipu_data, 1UL << channel, IPU_CHA_BUF0_RDY);
+	else
+		/* Mark buffer 1 as ready. */
+		idmac_write_ipureg(&ipu_data, 1UL << channel, IPU_CHA_BUF1_RDY);
+}
+
+/**
+ * Update the physical address of a buffer for a logical IPU channel.
+ *
+ * @param       channel         Input parameter for the logical channel ID.
+ *
+ * @param       type            Input parameter which buffer to initialize.
+ *
+ * @param       bufNum          Input parameter for which buffer number to update.
+ *                              0 or 1 are the only valid values.

+ *
+ * @param       phyaddr         Input parameter buffer physical address.
+ *
+ * @return      Returns 0 on success or negative error code on failure. This
+ *              function will fail if the buffer is set to ready.
+ */
+/* Called under spin_lock(_irqsave)(&ichan->lock) */
+static int ipu_update_channel_buffer(enum ipu_channel channel,
+				     int buffer_n, dma_addr_t phyaddr)
+{
+	uint32_t reg;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ipu_data.lock, flags);
+
+	if (buffer_n == 0) {
+		reg = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF0_RDY);
+		if (reg & (1UL << channel)) {
+			spin_unlock_irqrestore(&ipu_data.lock, flags);
+			return -EACCES;
+		}
+
+		/* 44.3.3.1.9 - Row Number 1 (WORD1, offset 0) */
+		idmac_write_ipureg(&ipu_data, dma_param_addr(channel) +
+				   0x0008UL, IPU_IMA_ADDR);
+		idmac_write_ipureg(&ipu_data, phyaddr, IPU_IMA_DATA);
+	} else {
+		reg = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF1_RDY);
+		if (reg & (1UL << channel)) {
+			spin_unlock_irqrestore(&ipu_data.lock, flags);
+			return -EACCES;
+		}
+
+		/* Check if double-buffering is already enabled */
+		reg = idmac_read_ipureg(&ipu_data, IPU_CHA_DB_MODE_SEL);
+
+		if (!(reg & (1UL << channel)))
+			idmac_write_ipureg(&ipu_data, reg | (1UL << channel),
+					   IPU_CHA_DB_MODE_SEL);
+
+		/* 44.3.3.1.9 - Row Number 1 (WORD1, offset 1) */
+		idmac_write_ipureg(&ipu_data, dma_param_addr(channel) +
+				   0x0009UL, IPU_IMA_ADDR);
+		idmac_write_ipureg(&ipu_data, phyaddr, IPU_IMA_DATA);
+	}
+
+	spin_unlock_irqrestore(&ipu_data.lock, flags);
+
+	return 0;
+}
+
+/* Called under spin_lock_irqsave(&ichan->lock) */
+static int ipu_submit_channel_buffers(struct idmac_channel *ichan,
+				      struct idmac_tx_desc *desc)
+{
+	struct scatterlist *sg;
+	int i, ret;
+
+	for (i = 0, sg = desc->sg; i < 2 && sg; i++) {
+		if (!ichan->sg[i]) {
+			ichan->sg[i] = sg;
+
+			/*
+			 * On first invocation this shouldn't be necessary, the
+			 * call to ipu_init_channel_buffer() above will set
+			 * addresses for us, so we could make it conditional
+			 * on status >= IPU_CHANNEL_ENABLED, but doing it again
+			 * shouldn't hurt either.
+			 */
+			ret = ipu_update_channel_buffer(ichan->dma_chan.chan_id, i,
+							sg_dma_address(sg));
+			if (ret < 0)
+				return ret;
+
+			ipu_select_buffer(ichan->dma_chan.chan_id, i);
+
+			sg = sg_next(sg);
+		}
+	}
+
+	return ret;
+}

+
+static dma_cookie_t idmac_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+	struct idmac_tx_desc *desc = to_tx_desc(tx);
+	struct idmac_channel *ichan = to_idmac_chan(tx->chan);
+	struct idmac *idmac = to_idmac(tx->chan->device);
+	struct ipu *ipu = to_ipu(idmac);
+	dma_cookie_t cookie;
+	unsigned long flags;
+
+	/* Sanity check */
+	if (!list_empty(&desc->list)) {
+		/* The descriptor doesn't belong to client */
+		dev_err(&ichan->dma_chan.dev->device,
+			"Descriptor %p not prepared!\n", tx);
+		return -EBUSY;
+	}
+
+	mutex_lock(&ichan->chan_mutex);
+
+	if (ichan->status < IPU_CHANNEL_READY) {
+		struct idmac_video_param *video = &ichan->params.video;
+		/*
+		 * Initial buffer assignment - the first two sg-entries from
+		 * the descriptor will end up in the IDMAC buffers
+		 */
+		dma_addr_t dma_1 = sg_is_last(desc->sg) ? 0 :
+			sg_dma_address(&desc->sg[1]);
+
+		WARN_ON(ichan->sg[0] || ichan->sg[1]);
+
+		cookie = ipu_init_channel_buffer(ichan,
+						 video->out_pixel_fmt,
+						 video->out_width,
+						 video->out_height,
+						 video->out_stride,
+						 IPU_ROTATE_NONE,
+						 sg_dma_address(&desc->sg[0]),
+						 dma_1);
+		if (cookie < 0)
+			goto out;
+	}
+
+	/* ipu->lock can be taken under ichan->lock, but not v.v. */
+	spin_lock_irqsave(&ichan->lock, flags);
+
+	/* submit_buffers() atomically verifies and fills empty sg slots */
+	ipu_submit_channel_buffers(ichan, desc);
+
+	spin_unlock_irqrestore(&ichan->lock, flags);
+
+	cookie = ichan->dma_chan.cookie;
+
+	if (++cookie < 0)
+		cookie = 1;
+
+	/* from dmaengine.h: "last cookie value returned to client" */
+	ichan->dma_chan.cookie = cookie;
+	tx->cookie = cookie;
+	spin_lock_irqsave(&ichan->lock, flags);
+	list_add_tail(&desc->list, &ichan->queue);
+	spin_unlock_irqrestore(&ichan->lock, flags);
+
+	if (ichan->status < IPU_CHANNEL_ENABLED) {
+		int ret = ipu_enable_channel(idmac, ichan);
+		if (ret < 0) {
+			cookie = ret;
+			spin_lock_irqsave(&ichan->lock, flags);
+			list_del_init(&desc->list);
+			spin_unlock_irqrestore(&ichan->lock, flags);
+			tx->cookie = cookie;
+			ichan->dma_chan.cookie = cookie;
+		}
+	}
+
+	dump_idmac_reg(ipu);
+
+out:
+	mutex_unlock(&ichan->chan_mutex);
+
+	return cookie;
+}
+
+/* Called with ichan->chan_mutex held */
+static int idmac_desc_alloc(struct idmac_channel *ichan, int n)
+{
+	struct idmac_tx_desc *desc = vmalloc(n * sizeof(struct idmac_tx_desc));
+	struct idmac *idmac = to_idmac(ichan->dma_chan.device);
+
+	if (!desc)
+		return -ENOMEM;
+
+	/* No interrupts, just disable the tasklet for a moment */
+	tasklet_disable(&to_ipu(idmac)->tasklet);
+
+	ichan->n_tx_desc = n;
+	ichan->desc = desc;
+	INIT_LIST_HEAD(&ichan->queue);
+	INIT_LIST_HEAD(&ichan->free_list);
+
+	while (n--) {
+		struct dma_async_tx_descriptor *txd = &desc->txd;
+
+		memset(txd, 0, sizeof(*txd));
+		dma_async_tx_descriptor_init(txd, &ichan->dma_chan);
+		txd->tx_submit		= idmac_tx_submit;
+		txd->chan		= &ichan->dma_chan;
+		INIT_LIST_HEAD(&txd->tx_list);
+
+		list_add(&desc->list, &ichan->free_list);
+
+		desc++;
+	}
+
+	tasklet_enable(&to_ipu(idmac)->tasklet);
+
+	return 0;
+}
+
+/**
+ * This function is called to initialize a logical IPU channel.
+ *
+ * @param       channel Input parameter for the logical channel ID to initalize.
+ *
+ * @param       params  Input parameter containing union of channel initialization
+ *                      parameters.
+ *
+ * @return      This function returns 0 on success or negative error code on fail
+ */
+static int ipu_init_channel(struct idmac *idmac, struct idmac_channel *ichan)
+{
+	union ipu_channel_param *params = &ichan->params;
+	uint32_t ipu_conf;
+	enum ipu_channel channel = ichan->dma_chan.chan_id;
+	unsigned long flags;
+	uint32_t reg;
+	struct ipu *ipu = to_ipu(idmac);
+	int ret = 0, n_desc = 0;
+
+	dev_dbg(ipu->dev, "init channel = %d\n", channel);
+
+	if (channel != IDMAC_SDC_0 && channel != IDMAC_SDC_1 &&
+	    channel != IDMAC_IC_7)
+		return -EINVAL;
+
+	spin_lock_irqsave(&ipu->lock, flags);
+
+	ipu_conf = _ipu_channel_conf_check(ipu, channel);
+
+	switch (channel) {
+	case IDMAC_IC_7:
+		n_desc = 16;
+		reg = idmac_read_icreg(ipu, IC_CONF);
+		idmac_write_icreg(ipu, reg & ~IC_CONF_CSI_MEM_WR_EN, IC_CONF);
+		break;
+	case IDMAC_IC_0:
+		n_desc = 16;
+		reg = idmac_read_ipureg(ipu, IPU_FS_PROC_FLOW);
+		idmac_write_ipureg(ipu, reg & ~FS_ENC_IN_VALID, IPU_FS_PROC_FLOW);
+		ret = _ipu_ic_init_prpenc(ipu, params, true);
+		break;
+	case IDMAC_SDC_0:
+	case IDMAC_SDC_1:
+		n_desc = 4;
+	default:
+		break;
+	}
+
+	ipu->channel_init_mask |= 1L << channel;
+
+	/* Enable IPU sub module */
+	ipu_conf |= _ipu_channel_conf_mask(channel);
+	idmac_write_ipureg(ipu, ipu_conf, IPU_CONF);
+
+	spin_unlock_irqrestore(&ipu->lock, flags);
+
+	if (n_desc && !ichan->desc)
+		ret = idmac_desc_alloc(ichan, n_desc);
+
+	dump_idmac_reg(ipu);
+
+	return ret;
+}
+
+/**
+ * This function is called to uninitialize a logical IPU channel.
+ *
+ * @param       channel Input parameter for the logical channel ID to uninitalize.
+ */
+static void ipu_uninit_channel(struct idmac *idmac, struct idmac_channel *ichan)
+{
+	enum ipu_channel channel = ichan->dma_chan.chan_id;
+	unsigned long flags;
+	uint32_t reg;
+	uint32_t mask = 0;
+	uint32_t ipu_conf;
+	struct ipu *ipu = to_ipu(idmac);
+
+	spin_lock_irqsave(&ipu->lock, flags);
+
+	if (!(ipu->channel_init_mask & (1L << channel))) {
+		dev_err(ipu->dev, "Channel already uninitialized %d\n",
+			channel);
+		spin_unlock_irqrestore(&ipu->lock, flags);
+		return;
+	}
+
+	/* Make sure channel is disabled */
+	if (mask & idmac_read_icreg(ipu, IDMAC_CHA_EN)) {
+		dev_err(ipu->dev,
+			"Channel %d is not disabled, disable first\n", channel);
+		spin_unlock_irqrestore(&ipu->lock, flags);
+		return;
+	}

+
+	/* Reset the double buffer */
+	reg = idmac_read_ipureg(ipu, IPU_CHA_DB_MODE_SEL);
+	idmac_write_ipureg(ipu, reg & ~mask, IPU_CHA_DB_MODE_SEL);
+
+	ichan->sec_chan_en = false;
+
+	switch (channel) {
+	case IDMAC_IC_7:
+		reg = idmac_read_icreg(ipu, IC_CONF);
+		idmac_write_icreg(ipu, reg & ~(IC_CONF_RWS_EN | IC_CONF_PRPENC_EN),
+			     IC_CONF);
+		break;
+	case IDMAC_IC_0:
+		reg = idmac_read_icreg(ipu, IC_CONF);
+		idmac_write_icreg(ipu, reg & ~(IC_CONF_PRPENC_EN | IC_CONF_PRPENC_CSC1),
+				  IC_CONF);
+		break;
+	case IDMAC_SDC_0:
+	case IDMAC_SDC_1:
+	default:
+		break;
+	}
+
+	ipu->channel_init_mask &= ~(1L << channel);
+
+	ipu_conf = idmac_read_ipureg(ipu, IPU_CONF);
+	ipu_conf &= ~_ipu_channel_conf_mask(channel);
+	idmac_write_ipureg(ipu, ipu_conf, IPU_CONF);
+	if (!ipu_conf)
+		clk_disable(ipu->ipu_clk);
+
+	spin_unlock_irqrestore(&ipu->lock, flags);
+
+	ichan->n_tx_desc = 0;
+	vfree(ichan->desc);
+	ichan->desc = NULL;
+}
+
+/**
+ * This function disables a logical channel.
+ *
+ * @param       channel         Input parameter for the logical channel ID.
+ *
+ * @param       wait_for_stop   Flag to set whether to wait for channel end
+ *                              of frame or return immediately.
+ *
+ * @return      This function returns 0 on success or negative error code on
+ *              fail.
+ */
+static int ipu_disable_channel(struct idmac *idmac, enum ipu_channel channel,
+			       bool wait_for_stop)
+{
+	struct ipu *ipu = to_ipu(idmac);
+	uint32_t reg;
+	unsigned long flags;
+	uint32_t chan_mask = 1UL << channel;
+	uint32_t timeout;
+	uint32_t eof_intr;
+
+	if (wait_for_stop && channel != IDMAC_SDC_1 && channel != IDMAC_SDC_0) {
+		timeout = 40;
+		/* This waiting always fails. Related to spurious irq problem */
+		while ((idmac_read_icreg(ipu, IDMAC_CHA_BUSY) & chan_mask) ||
+		       (_ipu_channel_status(ipu, channel) == TASK_STAT_ACTIVE)) {
+			timeout--;
+			msleep(10);
+
+			if (!timeout) {
+				dev_dbg(ipu->dev,
+					"Warning: timeout waiting for channel %u to "
+					"stop: buf0_rdy = 0x%08X, buf1_rdy = 0x%08X, "
+					"busy = 0x%08X, tstat = 0x%08X\n", channel,
+					idmac_read_ipureg(ipu, IPU_CHA_BUF0_RDY),
+					idmac_read_ipureg(ipu, IPU_CHA_BUF1_RDY),
+					idmac_read_icreg(ipu, IDMAC_CHA_BUSY),
+					idmac_read_ipureg(ipu, IPU_TASKS_STAT));
+				break;
+			}
+		}
+		dev_dbg(ipu->dev, "timeout = %d * 10ms\n", 40 - timeout);
+	}
+	/* SDC BG and FG must be disabled before DMA is disabled */
+	if (wait_for_stop && (channel == IDMAC_SDC_0 ||
+			      channel == IDMAC_SDC_1)) {
+		if (channel == IDMAC_SDC_0)
+			eof_intr = IPU_IRQ_SDC_BG_EOF;
+		else
+			eof_intr = IPU_IRQ_SDC_FG_EOF;
+
+		for (timeout = 5;
+		     timeout && !ipu_irq_status(eof_intr); timeout--)
+			msleep(5);
+	}
+
+	spin_lock_irqsave(&ipu->lock, flags);
+
+	/* Disable IC task */
+	_ipu_ic_disable_task(ipu, channel);
+
+	/* Disable DMA channel(s) */
+	reg = idmac_read_icreg(ipu, IDMAC_CHA_EN);
+	idmac_write_icreg(ipu, reg & ~chan_mask, IDMAC_CHA_EN);
+
+	/*
+	 * Problem (observed with channel DMAIC_7): after enabling the channel
+	 * and initialising buffers, there comes an interrupt with current still
+	 * pointing at buffer 0, whereas it should use buffer 0 first and only
+	 * generate an interrupt when it is done, then current should already
+	 * point to buffer 1. This spurious interrupt also comes on channel
+	 * DMASDC_0. With DMAIC_7 normally, is we just leave the ISR after the
+	 * first interrupt, there comes the second with current correctly
+	 * pointing to buffer 1 this time. But sometimes this second interrupt
+	 * doesn't come and the channel hangs. Clearing BUFx_RDY when disabling
+	 * the channel seems to prevent the channel from hanging, but it doesn't
+	 * prevent the spurious interrupt. This might also be unsafe. Think
+	 * about the IDMAC controller trying to switch to a buffer, when we
+	 * clear the ready bit, and re-enable it a moment later.
+	 */
+	reg = idmac_read_ipureg(ipu, IPU_CHA_BUF0_RDY);
+	idmac_write_ipureg(ipu, 0, IPU_CHA_BUF0_RDY);
+	idmac_write_ipureg(ipu, reg & ~(1UL << channel), IPU_CHA_BUF0_RDY);
+
+	reg = idmac_read_ipureg(ipu, IPU_CHA_BUF1_RDY);
+	idmac_write_ipureg(ipu, 0, IPU_CHA_BUF1_RDY);
+	idmac_write_ipureg(ipu, reg & ~(1UL << channel), IPU_CHA_BUF1_RDY);
+
+	spin_unlock_irqrestore(&ipu->lock, flags);
+
+	return 0;
+}
+
+/*
+ * We have several possibilities here:
+ * current BUF		next BUF
+ *
+ * not last sg		next not last sg
+ * not last sg		next last sg
+ * last sg		first sg from next descriptor
+ * last sg		NULL
+ *
+ * Besides, the descriptor queue might be empty or not. We process all these
+ * cases carefully.
+ */
+static irqreturn_t idmac_interrupt(int irq, void *dev_id)
+{
+	struct idmac_channel *ichan = dev_id;
+	unsigned int chan_id = ichan->dma_chan.chan_id;
+	struct scatterlist **sg, *sgnext, *sgnew = NULL;
+	/* Next transfer descriptor */
+	struct idmac_tx_desc *desc = NULL, *descnew;
+	dma_async_tx_callback callback;
+	void *callback_param;
+	bool done = false;
+	u32	ready0 = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF0_RDY),
+		ready1 = idmac_read_ipureg(&ipu_data, IPU_CHA_BUF1_RDY),
+		curbuf = idmac_read_ipureg(&ipu_data, IPU_CHA_CUR_BUF);
+
+	/* IDMAC has cleared the respective BUFx_RDY bit, we manage the buffer */
+
+	pr_debug("IDMAC irq %d\n", irq);
+	/* Other interrupts do not interfere with this channel */
+	spin_lock(&ichan->lock);
+
+	if (unlikely(chan_id != IDMAC_SDC_0 && chan_id != IDMAC_SDC_1 &&
+		     ((curbuf >> chan_id) & 1) == ichan->active_buffer)) {
+		int i = 100;
+
+		/* This doesn't help. See comment in ipu_disable_channel() */
+		while (--i) {
+			curbuf = idmac_read_ipureg(&ipu_data, IPU_CHA_CUR_BUF);
+			if (((curbuf >> chan_id) & 1) != ichan->active_buffer)
+				break;
+			cpu_relax();
+		}
+
+		if (!i) {
+			spin_unlock(&ichan->lock);
+			dev_err(ichan->dma_chan.device->dev,
+				"IRQ on active buffer on channel %x, active "
+				"%d, ready %x, %x, current %x!\n", chan_id,
+				ichan->active_buffer, ready0, ready1, curbuf);
+			return IRQ_NONE;
+		}
+	}
+
+	if (unlikely((ichan->active_buffer && (ready1 >> chan_id) & 1) ||
+		     (!ichan->active_buffer && (ready0 >> chan_id) & 1)
+		     )) {
+		spin_unlock(&ichan->lock);
+		dev_dbg(ichan->dma_chan.device->dev,
+			"IRQ with active buffer still ready on channel %x, "
+			"active %d, ready %x, %x!\n", chan_id,
+			ichan->active_buffer, ready0, ready1);
+		return IRQ_NONE;
+	}
+
+	if (unlikely(list_empty(&ichan->queue))) {
+		spin_unlock(&ichan->lock);
+		dev_err(ichan->dma_chan.device->dev,
+			"IRQ without queued buffers on channel %x, active %d, "
+			"ready %x, %x!\n", chan_id,
+			ichan->active_buffer, ready0, ready1);
+		return IRQ_NONE;
+	}
+
+	/*
+	 * active_buffer is a software flag, it shows which buffer we are
+	 * currently expecting back from the hardware, IDMAC should be
+	 * processing the other buffer already
+	 */
+	sg = &ichan->sg[ichan->active_buffer];
+	sgnext = ichan->sg[!ichan->active_buffer];
+
+	/*
+	 * if sgnext == NULL sg must be the last element in a scatterlist and
+	 * queue must be empty
+	 */
+	if (unlikely(!sgnext)) {
+		if (unlikely(sg_next(*sg))) {
+			dev_err(ichan->dma_chan.device->dev,
+				"Broken buffer-update locking on channel %x!\n",
+				chan_id);
+			/* We'll let the user catch up */
+		} else {
+			/* Underrun */
+			_ipu_ic_disable_task(&ipu_data, chan_id);
+			dev_dbg(ichan->dma_chan.device->dev,
+				"Underrun on channel %x\n", chan_id);
+			ichan->status = IPU_CHANNEL_READY;
+			/* Continue to check for complete descriptor */
+		}
+	}
+
+	desc = list_entry(ichan->queue.next, struct idmac_tx_desc, list);
+
+	/* First calculate and submit the next sg element */
+	if (likely(sgnext))
+		sgnew = sg_next(sgnext);
+
+	if (unlikely(!sgnew)) {
+		/* Start a new scatterlist, if any queued */
+		if (likely(desc->list.next != &ichan->queue)) {
+			descnew = list_entry(desc->list.next,
+					     struct idmac_tx_desc, list);
+			sgnew = &descnew->sg[0];
+		}
+	}
+
+	if (unlikely(!sg_next(*sg)) || !sgnext) {
+		/*
+		 * Last element in scatterlist done, remove from the queue,
+		 * _init for debugging
+		 */
+		list_del_init(&desc->list);
+		done = true;
+	}
+
+	*sg = sgnew;
+
+	if (likely(sgnew)) {
+		int ret;
+
+		ret = ipu_update_channel_buffer(chan_id, ichan->active_buffer,
+						sg_dma_address(*sg));
+		if (ret < 0)
+			dev_err(ichan->dma_chan.device->dev,
+				"Failed to update buffer on channel %x buffer %d!\n",
+				chan_id, ichan->active_buffer);
+		else
+			ipu_select_buffer(chan_id, ichan->active_buffer);
+	}
+
+	/* Flip the active buffer - even if update above failed */
+	ichan->active_buffer = !ichan->active_buffer;
+	if (done)
+		ichan->completed = desc->txd.cookie;
+
+	callback = desc->txd.callback;
+	callback_param = desc->txd.callback_param;
+
+	spin_unlock(&ichan->lock);
+
+	if (done && (desc->txd.flags & DMA_PREP_INTERRUPT) && callback)
+		callback(callback_param);
+
+	return IRQ_HANDLED;
+}
+
+static void ipu_gc_tasklet(unsigned long arg)
+{
+	struct ipu *ipu = (struct ipu *)arg;
+	int i;
+
+	for (i = 0; i < IPU_CHANNELS_NUM; i++) {
+		struct idmac_channel *ichan = ipu->channel + i;
+		struct idmac_tx_desc *desc;
+		unsigned long flags;
+		int j;
+
+		for (j = 0; j < ichan->n_tx_desc; j++) {
+			desc = ichan->desc + j;
+			spin_lock_irqsave(&ichan->lock, flags);
+			if (async_tx_test_ack(&desc->txd)) {
+				list_move(&desc->list, &ichan->free_list);
+				async_tx_clear_ack(&desc->txd);
+			}
+			spin_unlock_irqrestore(&ichan->lock, flags);
+		}
+	}
+}
+
+/*
+ * At the time .device_alloc_chan_resources() method is called, we cannot know,
+ * whether the client will accept the channel. Thus we must only check, if we
+ * can satisfy client's request but the only real criterion to verify, whether
+ * the client has accepted our offer is the client_count. That's why we have to
+ * perform the rest of our allocation tasks on the first call to this function.
+ */
+static struct dma_async_tx_descriptor *idmac_prep_slave_sg(struct dma_chan *chan,
+		struct scatterlist *sgl, unsigned int sg_len,
+		enum dma_data_direction direction, unsigned long tx_flags)
+{
+	struct idmac_channel *ichan = to_idmac_chan(chan);
+	struct idmac_tx_desc *desc = NULL;
+	struct dma_async_tx_descriptor *txd = NULL;
+	unsigned long flags;
+
+	/* We only can handle these three channels so far */
+	if (ichan->dma_chan.chan_id != IDMAC_SDC_0 && ichan->dma_chan.chan_id != IDMAC_SDC_1 &&
+	    ichan->dma_chan.chan_id != IDMAC_IC_7)
+		return NULL;
+
+	if (direction != DMA_FROM_DEVICE && direction != DMA_TO_DEVICE) {
+		dev_err(chan->device->dev, "Invalid DMA direction %d!\n", direction);
+		return NULL;
+	}
+
+	mutex_lock(&ichan->chan_mutex);
+
+	spin_lock_irqsave(&ichan->lock, flags);
+	if (!list_empty(&ichan->free_list)) {
+		desc = list_entry(ichan->free_list.next,
+				  struct idmac_tx_desc, list);
+
+		list_del_init(&desc->list);
+
+		desc->sg_len	= sg_len;
+		desc->sg	= sgl;
+		txd		= &desc->txd;
+		txd->flags	= tx_flags;
+	}
+	spin_unlock_irqrestore(&ichan->lock, flags);
+
+	mutex_unlock(&ichan->chan_mutex);
+
+	tasklet_schedule(&to_ipu(to_idmac(chan->device))->tasklet);
+
+	return txd;
+}
+
+/* Re-select the current buffer and re-activate the channel */
+static void idmac_issue_pending(struct dma_chan *chan)
+{
+	struct idmac_channel *ichan = to_idmac_chan(chan);
+	struct idmac *idmac = to_idmac(chan->device);
+	struct ipu *ipu = to_ipu(idmac);
+	unsigned long flags;
+
+	/* This is not always needed, but doesn't hurt either */
+	spin_lock_irqsave(&ipu->lock, flags);
+	ipu_select_buffer(ichan->dma_chan.chan_id, ichan->active_buffer);
+	spin_unlock_irqrestore(&ipu->lock, flags);
+
+	/*
+	 * Might need to perform some parts of initialisation from
+	 * ipu_enable_channel(), but not all, we do not want to reset to buffer
+	 * 0, don't need to set priority again either, but re-enabling the task
+	 * and the channel might be a good idea.
+	 */
+}
+
+static void __idmac_terminate_all(struct dma_chan *chan)
+{
+	struct idmac_channel *ichan = to_idmac_chan(chan);
+	struct idmac *idmac = to_idmac(chan->device);
+	unsigned long flags;
+	int i;
+
+	ipu_disable_channel(idmac, chan->chan_id,
+			    ichan->status >= IPU_CHANNEL_ENABLED);
+
+	/* ichan->queue is modified in ISR, have to spinlock */
+	tasklet_disable(&to_ipu(idmac)->tasklet);
+
+	spin_lock_irqsave(&ichan->lock, flags);
+	list_splice_init(&ichan->queue, &ichan->free_list);
+
+	if (ichan->desc)
+		for (i = 0; i < ichan->n_tx_desc; i++) {
+			struct idmac_tx_desc *desc = ichan->desc + i;
+			if (list_empty(&desc->list))
+				/* Descriptor was prepared, but not submitted */
+				list_add(&desc->list,
+					 &ichan->free_list);
+
+			async_tx_clear_ack(&desc->txd);
+		}
+
+	ichan->sg[0] = NULL;
+	ichan->sg[1] = NULL;
+	spin_unlock_irqrestore(&ichan->lock, flags);
+
+	tasklet_enable(&to_ipu(idmac)->tasklet);
+
+	ichan->status = IPU_CHANNEL_INITIALIZED;
+}
+
+static void idmac_terminate_all(struct dma_chan *chan)
+{
+	struct idmac_channel *ichan = to_idmac_chan(chan);
+
+	mutex_lock(&ichan->chan_mutex);
+
+	__idmac_terminate_all(chan);
+
+	mutex_unlock(&ichan->chan_mutex);
+}
+
+static int idmac_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct idmac_channel *ichan = to_idmac_chan(chan);
+	struct idmac *idmac = to_idmac(chan->device);
+	int ret;
+
+	/* dmaengine.c now guarantees to only offer free channels */
+	BUG_ON(chan->client_count > 1);
+	WARN_ON(ichan->status != IPU_CHANNEL_FREE);
+
+	/* The channel is free yet, no need to protect? */
+	mutex_lock(&ichan->chan_mutex);

+
+	chan->cookie		= 1;
+	ichan->completed	= -ENXIO;
+
+	ret = request_irq(ichan->eof_irq, idmac_interrupt, 0,
+			  "idmac", ichan);
+	if (ret < 0)
+		goto out;
+
+	ret = ipu_init_channel(idmac, ichan);
+	if (ret < 0) {
+		free_irq(ichan->eof_irq, ichan);
+		goto out;
+	}
+
+	ichan->status = IPU_CHANNEL_INITIALIZED;
+
+out:
+	mutex_unlock(&ichan->chan_mutex);
+
+	dev_dbg(&ichan->dma_chan.dev->device, "Found channel 0x%x, irq %d\n",
+		ichan->dma_chan.chan_id, ichan->eof_irq);

+}
+
+static void idmac_free_chan_resources(struct dma_chan *chan)
+{
+	struct idmac_channel *ichan = to_idmac_chan(chan);
+	struct idmac *idmac = to_idmac(chan->device);
+
+	mutex_lock(&ichan->chan_mutex);
+
+	__idmac_terminate_all(chan);
+
+	if (ichan->status > IPU_CHANNEL_FREE)
+		free_irq(ichan->eof_irq, ichan);
+
+	ichan->status = IPU_CHANNEL_FREE;
+
+	/*
+	 * The channel should be uninitialized by now already, but the original
+	 * Freescale driver did it again, and it shouldn't hurt
+	 */

+	ipu_uninit_channel(idmac, ichan);
+
+	mutex_unlock(&ichan->chan_mutex);
+
+	tasklet_schedule(&to_ipu(idmac)->tasklet);
+}
+
+static enum dma_status idmac_is_tx_complete(struct dma_chan *chan,
+		dma_cookie_t cookie, dma_cookie_t *done, dma_cookie_t *used)
+{
+	struct idmac_channel *ichan = to_idmac_chan(chan);
+
+	if (done)
+		*done = ichan->completed;
+	if (used)
+		*used = chan->cookie;
+	if (cookie != chan->cookie)
+		return DMA_ERROR;
+	return DMA_SUCCESS;
+}
+
+static int __init ipu_idmac_init(struct ipu *ipu)
+{
+	struct idmac *idmac = &ipu->idmac;
+	struct dma_device *dma = &idmac->dma;
+	int i;
+
+	dma_cap_set(DMA_SLAVE, dma->cap_mask);
+	dma_cap_set(DMA_PRIVATE, dma->cap_mask);
+
+	/* Compulsory common fields */
+	dma->dev				= ipu->dev;
+	dma->device_alloc_chan_resources	= idmac_alloc_chan_resources;
+	dma->device_free_chan_resources		= idmac_free_chan_resources;
+	dma->device_is_tx_complete		= idmac_is_tx_complete;
+	dma->device_issue_pending		= idmac_issue_pending;
+
+	/* Compulsory for DMA_SLAVE fields */
+	dma->device_prep_slave_sg		= idmac_prep_slave_sg;
+	dma->device_terminate_all		= idmac_terminate_all;
+
+	INIT_LIST_HEAD(&dma->channels);
+	for (i = 0; i < IPU_CHANNELS_NUM; i++) {
+		struct idmac_channel *ichan = ipu->channel + i;
+		struct dma_chan *dma_chan = &ichan->dma_chan;
+
+		spin_lock_init(&ichan->lock);
+		mutex_init(&ichan->chan_mutex);

+
+		ichan->eof_irq		= MXC_IPU_INT_BASE + i;
+		ichan->status		= IPU_CHANNEL_FREE;
+		ichan->sec_chan_en	= false;
+		ichan->completed	= -ENXIO;
+
+		dma_chan->device	= &idmac->dma;
+		dma_chan->cookie	= 1;
+		dma_chan->chan_id	= i;
+		list_add_tail(&ichan->dma_chan.device_node, &dma->channels);
+	}
+
+	idmac_write_icreg(ipu, 0x00000070, IDMAC_CONF);
+
+	return dma_async_device_register(&idmac->dma);
+}
+
+static void ipu_idmac_exit(struct ipu *ipu)
+{
+	int i;
+	struct idmac *idmac = &ipu->idmac;
+
+	for (i = 0; i < IPU_CHANNELS_NUM; i++) {
+		struct idmac_channel *ichan = ipu->channel + i;
+
+		idmac_terminate_all(&ichan->dma_chan);
+		idmac_prep_slave_sg(&ichan->dma_chan, NULL, 0, DMA_NONE, 0);
+	}
+
+	dma_async_device_unregister(&idmac->dma);
+}
+
+/*****************************************************************************
+ * IPU common probe / remove
+ */
+
+static int ipu_probe(struct platform_device *pdev)
+{
+	struct ipu_platform_data *pdata = pdev->dev.platform_data;
+	struct resource *mem_ipu, *mem_ic;
+	int ret;
+
+	spin_lock_init(&ipu_data.lock);
+
+	mem_ipu	= platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mem_ic	= platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!pdata || !mem_ipu || !mem_ic)
+		return -EINVAL;
+
+	ipu_data.dev = &pdev->dev;
+
+	platform_set_drvdata(pdev, &ipu_data);
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		goto err_noirq;
+
+	ipu_data.irq_fn = ret;
+	ret = platform_get_irq(pdev, 1);
+	if (ret < 0)
+		goto err_noirq;
+
+	ipu_data.irq_err = ret;
+	ipu_data.irq_base = pdata->irq_base;
+
+	dev_dbg(&pdev->dev, "fn irq %u, err irq %u, irq-base %u\n",
+		ipu_data.irq_fn, ipu_data.irq_err, ipu_data.irq_base);
+
+	/* Remap IPU common registers */
+	ipu_data.reg_ipu = ioremap(mem_ipu->start,
+				   mem_ipu->end - mem_ipu->start + 1);
+	if (!ipu_data.reg_ipu) {
+		ret = -ENOMEM;
+		goto err_ioremap_ipu;
+	}
+
+	/* Remap Image Converter and Image DMA Controller registers */
+	ipu_data.reg_ic = ioremap(mem_ic->start,
+				  mem_ic->end - mem_ic->start + 1);
+	if (!ipu_data.reg_ic) {
+		ret = -ENOMEM;
+		goto err_ioremap_ic;
+	}
+
+	/* Get IPU clock */
+	ipu_data.ipu_clk = clk_get(&pdev->dev, "ipu_clk");
+	if (IS_ERR(ipu_data.ipu_clk)) {
+		ret = PTR_ERR(ipu_data.ipu_clk);
+		goto err_clk_get;
+	}
+
+	/* Make sure IPU HSP clock is running */
+	clk_enable(ipu_data.ipu_clk);

+
+	/* Disable all interrupts */
+	idmac_write_ipureg(&ipu_data, 0, IPU_INT_CTRL_1);
+	idmac_write_ipureg(&ipu_data, 0, IPU_INT_CTRL_2);
+	idmac_write_ipureg(&ipu_data, 0, IPU_INT_CTRL_3);
+	idmac_write_ipureg(&ipu_data, 0, IPU_INT_CTRL_4);
+	idmac_write_ipureg(&ipu_data, 0, IPU_INT_CTRL_5);
+
+	dev_dbg(&pdev->dev, "%s @ 0x%08lx, fn irq %u, err irq %u\n", pdev->name,
+		(unsigned long)mem_ipu->start, ipu_data.irq_fn, ipu_data.irq_err);
+
+	ret = ipu_irq_attach_irq(&ipu_data, pdev);
+	if (ret < 0)
+		goto err_attach_irq;
+
+	/* Initialize DMA engine */
+	ret = ipu_idmac_init(&ipu_data);
+	if (ret < 0)
+		goto err_idmac_init;
+
+	tasklet_init(&ipu_data.tasklet, ipu_gc_tasklet, (unsigned long)&ipu_data);
+
+	ipu_data.dev = &pdev->dev;
+
+	dev_dbg(ipu_data.dev, "IPU initialized\n");
+
+	return 0;
+
+err_idmac_init:
+err_attach_irq:
+	ipu_irq_detach_irq(&ipu_data, pdev);
+	clk_put(ipu_data.ipu_clk);
+err_clk_get:
+	iounmap(ipu_data.reg_ic);
+err_ioremap_ic:
+	iounmap(ipu_data.reg_ipu);
+err_ioremap_ipu:
+err_noirq:
+	dev_err(&pdev->dev, "Failed to probe IPU: %d\n", ret);
+	return ret;
+}
+
+static int ipu_remove(struct platform_device *pdev)
+{
+	struct ipu *ipu = platform_get_drvdata(pdev);
+
+	ipu_idmac_exit(ipu);
+	ipu_irq_detach_irq(ipu, pdev);
+	clk_put(ipu->ipu_clk);
+	iounmap(ipu->reg_ic);
+	iounmap(ipu->reg_ipu);
+	tasklet_kill(&ipu->tasklet);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+/*
+ * We need two MEM resources - with IPU-common and Image Converter registers,
+ * including PF_CONF and IDMAC_* registers, and two IRQs - function and error
+ */
+static struct platform_driver ipu_platform_driver = {
+	.driver = {
+		.name	= "ipu-core",
+		.owner	= THIS_MODULE,
+	},
+	.remove		= ipu_remove,
+};
+
+static int __init ipu_init(void)
+{
+	return platform_driver_probe(&ipu_platform_driver, ipu_probe);
+}
+subsys_initcall(ipu_init);
+
+MODULE_DESCRIPTION("IPU core driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Guennadi Liakhovetski <lg@denx.de>");
+MODULE_ALIAS("platform:ipu-core");

+
+#endif

diff --git a/drivers/mfd/ipu/ipu_irq.c b/drivers/mfd/ipu/ipu_irq.c
new file mode 100644
index 0000000..3239d6b
--- /dev/null
+++ b/drivers/mfd/ipu/ipu_irq.c

@@ -0,0 +1,277 @@
+/*
+ * Copyright (C) 2008
+ * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
+ *
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/irq.h>
+
+#include <asm/io.h>

+
+#include <mach/ipu.h>
+
+#include "ipu_intern.h"
+
+/*
+ * Register read / write - shall be inlined by the compiler
+ */
+static u32 ipu_read_reg(struct ipu *ipu, unsigned long reg)
+{
+	return __raw_readl(ipu->reg_ipu + reg);
+}
+
+static void ipu_write_reg(struct ipu *ipu, u32 value, unsigned long reg)
+{
+	__raw_writel(value, ipu->reg_ipu + reg);
+}
+
+
+/*
+ * IPU IRQ chip driver
+ */
+
+#define IPU_IRQ_NR_FN_BANKS 3
+#define IPU_IRQ_NR_ERR_BANKS 2
+
+struct ipu_irq_bank {
+	int		nr_irqs;
+	unsigned int	control;
+	unsigned int	status;
+	unsigned int	irq_base;
+	spinlock_t	lock;
+	struct ipu	*ipu;
+};
+
+static struct ipu_irq_bank irq_bank_fn[IPU_IRQ_NR_FN_BANKS] = {
+	/* 3 groups of functional interrupts */
+	{
+		.nr_irqs	= 32,
+		.control	= IPU_INT_CTRL_1,
+		.status		= IPU_INT_STAT_1,
+	}, {
+		.nr_irqs	= 32,
+		.control	= IPU_INT_CTRL_2,
+		.status		= IPU_INT_STAT_2,
+	}, {
+		.nr_irqs	= 24,
+		.control	= IPU_INT_CTRL_3,
+		.status		= IPU_INT_STAT_3,
+	},
+};
+
+static struct ipu_irq_bank irq_bank_err[IPU_IRQ_NR_ERR_BANKS] = {
+	/* 2 groups of error interrupts */
+	{
+		.nr_irqs	= 32,
+		.control	= IPU_INT_CTRL_4,
+		.status		= IPU_INT_STAT_4,
+	}, {
+		.nr_irqs	= 17,
+		.control	= IPU_INT_CTRL_5,
+		.status		= IPU_INT_STAT_5,
+	},
+};
+
+#define IPU_IRQ_NR_FN_IRQS (32 + 32 + 24)
+#define IPU_IRQ_NR_ERR_IRQS (32 + 17)
+#define IPU_IRQ_NR_IRQS (IPU_IRQ_NR_ERR_IRQS + IPU_IRQ_NR_FN_IRQS)