// SPDX-License-Identifier: GPL-2.0
/*
 * c8sectpfe-core.c - C8SECTPFE STi DVB driver
 *
 * Copyright (c) STMicroelectronics 2015
 *
 *   Author:Peter Bennett <peter.bennett@st.com>
 *          Peter Griffin <peter.griffin@linaro.org>
 *
 */
#include <linux/atomic.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/dvb/dmx.h>
#include <linux/dvb/frontend.h>
#include <linux/errno.h>
#include <linux/firmware.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_gpio.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/usb.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/version.h>
#include <linux/wait.h>
#include <linux/pinctrl/pinctrl.h>

#include "c8sectpfe-core.h"
#include "c8sectpfe-common.h"
#include "c8sectpfe-debugfs.h"
#include <media/dmxdev.h>
#include <media/dvb_demux.h>
#include <media/dvb_frontend.h>
#include <media/dvb_net.h>

#define FIRMWARE_MEMDMA "pti_memdma_h407.elf"
MODULE_FIRMWARE(FIRMWARE_MEMDMA);

#define PID_TABLE_SIZE 1024
#define POLL_MSECS 50

static int load_c8sectpfe_fw(struct c8sectpfei *fei);

#define TS_PKT_SIZE 188
#define HEADER_SIZE (4)
#define PACKET_SIZE (TS_PKT_SIZE+HEADER_SIZE)

#define FEI_ALIGNMENT (32)
/* hw requires minimum of 8*PACKET_SIZE and padded to 8byte boundary */
#define FEI_BUFFER_SIZE (8*PACKET_SIZE*340)

#define FIFO_LEN 1024

static void c8sectpfe_timer_interrupt(struct timer_list *t)
{
        struct c8sectpfei *fei = from_timer(fei, t, timer);
        struct channel_info *channel;
        int chan_num;

        /* iterate through input block channels */
        for (chan_num = 0; chan_num < fei->tsin_count; chan_num++) {
                channel = fei->channel_data[chan_num];

                /* is this descriptor initialised and TP enabled */
                if (channel->irec && readl(channel->irec + DMA_PRDS_TPENABLE))
                        tasklet_schedule(&channel->tsklet);
        }

        fei->timer.expires = jiffies +  msecs_to_jiffies(POLL_MSECS);
        add_timer(&fei->timer);
}

static void channel_swdemux_tsklet(unsigned long data)
{
        struct channel_info *channel = (struct channel_info *)data;
        struct c8sectpfei *fei;
        unsigned long wp, rp;
        int pos, num_packets, n, size;
        u8 *buf;

        if (unlikely(!channel || !channel->irec))
                return;

        fei = channel->fei;

        wp = readl(channel->irec + DMA_PRDS_BUSWP_TP(0));
        rp = readl(channel->irec + DMA_PRDS_BUSRP_TP(0));

        pos = rp - channel->back_buffer_busaddr;

        /* has it wrapped */
        if (wp < rp)
                wp = channel->back_buffer_busaddr + FEI_BUFFER_SIZE;

        size = wp - rp;
        num_packets = size / PACKET_SIZE;

        /* manage cache so data is visible to CPU */
        dma_sync_single_for_cpu(fei->dev,
                                rp,
                                size,
                                DMA_FROM_DEVICE);

        buf = (u8 *) channel->back_buffer_aligned;

        dev_dbg(fei->dev,
                "chan=%d channel=%p num_packets = %d, buf = %p, pos = 0x%x\n\trp=0x%lx, wp=0x%lx\n",
                channel->tsin_id, channel, num_packets, buf, pos, rp, wp);

        for (n = 0; n < num_packets; n++) {
                dvb_dmx_swfilter_packets(
                        &fei->c8sectpfe[0]->
                                demux[channel->demux_mapping].dvb_demux,
                        &buf[pos], 1);

                pos += PACKET_SIZE;
        }

        /* advance the read pointer */
        if (wp == (channel->back_buffer_busaddr + FEI_BUFFER_SIZE))
                writel(channel->back_buffer_busaddr, channel->irec +
                        DMA_PRDS_BUSRP_TP(0));
        else
                writel(wp, channel->irec + DMA_PRDS_BUSRP_TP(0));
}

static int c8sectpfe_start_feed(struct dvb_demux_feed *dvbdmxfeed)
{
        struct dvb_demux *demux = dvbdmxfeed->demux;
        struct stdemux *stdemux = (struct stdemux *)demux->priv;
        struct c8sectpfei *fei = stdemux->c8sectpfei;
        struct channel_info *channel;
        u32 tmp;
        unsigned long *bitmap;
        int ret;

        switch (dvbdmxfeed->type) {
        case DMX_TYPE_TS:
                break;
        case DMX_TYPE_SEC:
                break;
        default:
                dev_err(fei->dev, "%s:%d Error bailing\n"
                        , __func__, __LINE__);
                return -EINVAL;
        }

        if (dvbdmxfeed->type == DMX_TYPE_TS) {
                switch (dvbdmxfeed->pes_type) {
                case DMX_PES_VIDEO:
                case DMX_PES_AUDIO:
                case DMX_PES_TELETEXT:
                case DMX_PES_PCR:
                case DMX_PES_OTHER:
                        break;
                default:
                        dev_err(fei->dev, "%s:%d Error bailing\n"
                                , __func__, __LINE__);
                        return -EINVAL;
                }
        }

        if (!atomic_read(&fei->fw_loaded)) {
                ret = load_c8sectpfe_fw(fei);
                if (ret)
                        return ret;
        }

        mutex_lock(&fei->lock);

        channel = fei->channel_data[stdemux->tsin_index];

        bitmap = (unsigned long *) channel->pid_buffer_aligned;

        /* 8192 is a special PID */
        if (dvbdmxfeed->pid == 8192) {
                tmp = readl(fei->io + C8SECTPFE_IB_PID_SET(channel->tsin_id));
                tmp &= ~C8SECTPFE_PID_ENABLE;
                writel(tmp, fei->io + C8SECTPFE_IB_PID_SET(channel->tsin_id));

        } else {
                bitmap_set(bitmap, dvbdmxfeed->pid, 1);
        }

        /* manage cache so PID bitmap is visible to HW */
        dma_sync_single_for_device(fei->dev,
                                        channel->pid_buffer_busaddr,
                                        PID_TABLE_SIZE,
                                        DMA_TO_DEVICE);

        channel->active = 1;

        if (fei->global_feed_count == 0) {
                fei->timer.expires = jiffies +
                        msecs_to_jiffies(msecs_to_jiffies(POLL_MSECS));

                add_timer(&fei->timer);
        }

        if (stdemux->running_feed_count == 0) {

                dev_dbg(fei->dev, "Starting channel=%p\n", channel);

                tasklet_init(&channel->tsklet, channel_swdemux_tsklet,
                             (unsigned long) channel);

                /* Reset the internal inputblock sram pointers */
                writel(channel->fifo,
                        fei->io + C8SECTPFE_IB_BUFF_STRT(channel->tsin_id));
                writel(channel->fifo + FIFO_LEN - 1,
                        fei->io + C8SECTPFE_IB_BUFF_END(channel->tsin_id));

                writel(channel->fifo,
                        fei->io + C8SECTPFE_IB_READ_PNT(channel->tsin_id));
                writel(channel->fifo,
                        fei->io + C8SECTPFE_IB_WRT_PNT(channel->tsin_id));


                /* reset read / write memdma ptrs for this channel */
                writel(channel->back_buffer_busaddr, channel->irec +
                        DMA_PRDS_BUSBASE_TP(0));

                tmp = channel->back_buffer_busaddr + FEI_BUFFER_SIZE - 1;
                writel(tmp, channel->irec + DMA_PRDS_BUSTOP_TP(0));

                writel(channel->back_buffer_busaddr, channel->irec +
                        DMA_PRDS_BUSWP_TP(0));

                /* Issue a reset and enable InputBlock */
                writel(C8SECTPFE_SYS_ENABLE | C8SECTPFE_SYS_RESET
                        , fei->io + C8SECTPFE_IB_SYS(channel->tsin_id));

                /* and enable the tp */
                writel(0x1, channel->irec + DMA_PRDS_TPENABLE);

                dev_dbg(fei->dev, "%s:%d Starting DMA feed on stdemux=%p\n"
                        , __func__, __LINE__, stdemux);
        }

        stdemux->running_feed_count++;
        fei->global_feed_count++;

        mutex_unlock(&fei->lock);

        return 0;
}

static int c8sectpfe_stop_feed(struct dvb_demux_feed *dvbdmxfeed)
{

        struct dvb_demux *demux = dvbdmxfeed->demux;
        struct stdemux *stdemux = (struct stdemux *)demux->priv;
        struct c8sectpfei *fei = stdemux->c8sectpfei;
        struct channel_info *channel;
        int idlereq;
        u32 tmp;
        int ret;
        unsigned long *bitmap;

        if (!atomic_read(&fei->fw_loaded)) {
                ret = load_c8sectpfe_fw(fei);
                if (ret)
                        return ret;
        }

        mutex_lock(&fei->lock);

        channel = fei->channel_data[stdemux->tsin_index];

        bitmap = (unsigned long *) channel->pid_buffer_aligned;

        if (dvbdmxfeed->pid == 8192) {
                tmp = readl(fei->io + C8SECTPFE_IB_PID_SET(channel->tsin_id));
                tmp |= C8SECTPFE_PID_ENABLE;
                writel(tmp, fei->io + C8SECTPFE_IB_PID_SET(channel->tsin_id));
        } else {
                bitmap_clear(bitmap, dvbdmxfeed->pid, 1);
        }

        /* manage cache so data is visible to HW */
        dma_sync_single_for_device(fei->dev,
                                        channel->pid_buffer_busaddr,
                                        PID_TABLE_SIZE,
                                        DMA_TO_DEVICE);

        if (--stdemux->running_feed_count == 0) {

                channel = fei->channel_data[stdemux->tsin_index];

                /* TP re-configuration on page 168 of functional spec */

                /* disable IB (prevents more TS data going to memdma) */
                writel(0, fei->io + C8SECTPFE_IB_SYS(channel->tsin_id));

                /* disable this channels descriptor */
                writel(0,  channel->irec + DMA_PRDS_TPENABLE);

                tasklet_disable(&channel->tsklet);

                /* now request memdma channel goes idle */
                idlereq = (1 << channel->tsin_id) | IDLEREQ;
                writel(idlereq, fei->io + DMA_IDLE_REQ);

                /* wait for idle irq handler to signal completion */
                ret = wait_for_completion_timeout(&channel->idle_completion,
                                                msecs_to_jiffies(100));

                if (ret == 0)
                        dev_warn(fei->dev,
                                "Timeout waiting for idle irq on tsin%d\n",
                                channel->tsin_id);

                reinit_completion(&channel->idle_completion);

                /* reset read / write ptrs for this channel */

                writel(channel->back_buffer_busaddr,
                        channel->irec + DMA_PRDS_BUSBASE_TP(0));

                tmp = channel->back_buffer_busaddr + FEI_BUFFER_SIZE - 1;
                writel(tmp, channel->irec + DMA_PRDS_BUSTOP_TP(0));

                writel(channel->back_buffer_busaddr,
                        channel->irec + DMA_PRDS_BUSWP_TP(0));

                dev_dbg(fei->dev,
                        "%s:%d stopping DMA feed on stdemux=%p channel=%d\n",
                        __func__, __LINE__, stdemux, channel->tsin_id);

                /* turn off all PIDS in the bitmap */
                memset((void *)channel->pid_buffer_aligned
                        , 0x00, PID_TABLE_SIZE);

                /* manage cache so data is visible to HW */
                dma_sync_single_for_device(fei->dev,
                                        channel->pid_buffer_busaddr,
                                        PID_TABLE_SIZE,
                                        DMA_TO_DEVICE);

                channel->active = 0;
        }

        if (--fei->global_feed_count == 0) {
                dev_dbg(fei->dev, "%s:%d global_feed_count=%d\n"
                        , __func__, __LINE__, fei->global_feed_count);

                del_timer(&fei->timer);
        }

        mutex_unlock(&fei->lock);

        return 0;
}

static struct channel_info *find_channel(struct c8sectpfei *fei, int tsin_num)
{
        int i;

        for (i = 0; i < C8SECTPFE_MAX_TSIN_CHAN; i++) {
                if (!fei->channel_data[i])
                        continue;

                if (fei->channel_data[i]->tsin_id == tsin_num)
                        return fei->channel_data[i];
        }

        return NULL;
}

static void c8sectpfe_getconfig(struct c8sectpfei *fei)
{
        struct c8sectpfe_hw *hw = &fei->hw_stats;

        hw->num_ib = readl(fei->io + SYS_CFG_NUM_IB);
        hw->num_mib = readl(fei->io + SYS_CFG_NUM_MIB);
        hw->num_swts = readl(fei->io + SYS_CFG_NUM_SWTS);
        hw->num_tsout = readl(fei->io + SYS_CFG_NUM_TSOUT);
        hw->num_ccsc = readl(fei->io + SYS_CFG_NUM_CCSC);
        hw->num_ram = readl(fei->io + SYS_CFG_NUM_RAM);
        hw->num_tp = readl(fei->io + SYS_CFG_NUM_TP);

        dev_info(fei->dev, "C8SECTPFE hw supports the following:\n");
        dev_info(fei->dev, "Input Blocks: %d\n", hw->num_ib);
        dev_info(fei->dev, "Merged Input Blocks: %d\n", hw->num_mib);
        dev_info(fei->dev, "Software Transport Stream Inputs: %d\n"
                                , hw->num_swts);
        dev_info(fei->dev, "Transport Stream Output: %d\n", hw->num_tsout);
        dev_info(fei->dev, "Cable Card Converter: %d\n", hw->num_ccsc);
        dev_info(fei->dev, "RAMs supported by C8SECTPFE: %d\n", hw->num_ram);
        dev_info(fei->dev, "Tango TPs supported by C8SECTPFE: %d\n"
                        , hw->num_tp);
}

static irqreturn_t c8sectpfe_idle_irq_handler(int irq, void *priv)
{
        struct c8sectpfei *fei = priv;
        struct channel_info *chan;
        int bit;
        unsigned long tmp = readl(fei->io + DMA_IDLE_REQ);

        /* page 168 of functional spec: Clear the idle request
           by writing 0 to the C8SECTPFE_DMA_IDLE_REQ register. */

        /* signal idle completion */
        for_each_set_bit(bit, &tmp, fei->hw_stats.num_ib) {

                chan = find_channel(fei, bit);

                if (chan)
                        complete(&chan->idle_completion);
        }

        writel(0, fei->io + DMA_IDLE_REQ);

        return IRQ_HANDLED;
}


static void free_input_block(struct c8sectpfei *fei, struct channel_info *tsin)
{
        if (!fei || !tsin)
                return;

        if (tsin->back_buffer_busaddr)
                if (!dma_mapping_error(fei->dev, tsin->back_buffer_busaddr))
                        dma_unmap_single(fei->dev, tsin->back_buffer_busaddr,
                                FEI_BUFFER_SIZE, DMA_BIDIRECTIONAL);

        kfree(tsin->back_buffer_start);

        if (tsin->pid_buffer_busaddr)
                if (!dma_mapping_error(fei->dev, tsin->pid_buffer_busaddr))
                        dma_unmap_single(fei->dev, tsin->pid_buffer_busaddr,
                                PID_TABLE_SIZE, DMA_BIDIRECTIONAL);

        kfree(tsin->pid_buffer_start);
}

#define MAX_NAME 20

static int configure_memdma_and_inputblock(struct c8sectpfei *fei,
                                struct channel_info *tsin)
{
        int ret;
        u32 tmp;
        char tsin_pin_name[MAX_NAME];

        if (!fei || !tsin)
                return -EINVAL;

        dev_dbg(fei->dev, "%s:%d Configuring channel=%p tsin=%d\n"
                , __func__, __LINE__, tsin, tsin->tsin_id);

        init_completion(&tsin->idle_completion);

        tsin->back_buffer_start = kzalloc(FEI_BUFFER_SIZE +
                                        FEI_ALIGNMENT, GFP_KERNEL);

        if (!tsin->back_buffer_start) {
                ret = -ENOMEM;
                goto err_unmap;
        }

        /* Ensure backbuffer is 32byte aligned */
        tsin->back_buffer_aligned = tsin->back_buffer_start
                + FEI_ALIGNMENT;

        tsin->back_buffer_aligned = (void *)
                (((uintptr_t) tsin->back_buffer_aligned) & ~0x1F);

        tsin->back_buffer_busaddr = dma_map_single(fei->dev,
                                        (void *)tsin->back_buffer_aligned,
                                        FEI_BUFFER_SIZE,
                                        DMA_BIDIRECTIONAL);

        if (dma_mapping_error(fei->dev, tsin->back_buffer_busaddr)) {
                dev_err(fei->dev, "failed to map back_buffer\n");
                ret = -EFAULT;
                goto err_unmap;
        }

        /*
         * The pid buffer can be configured (in hw) for byte or bit
         * per pid. By powers of deduction we conclude stih407 family
         * is configured (at SoC design stage) for bit per pid.
         */
        tsin->pid_buffer_start = kzalloc(2048, GFP_KERNEL);

        if (!tsin->pid_buffer_start) {
                ret = -ENOMEM;
                goto err_unmap;
        }

        /*
         * PID buffer needs to be aligned to size of the pid table
         * which at bit per pid is 1024 bytes (8192 pids / 8).
         * PIDF_BASE register enforces this alignment when writing
         * the register.
         */

        tsin->pid_buffer_aligned = tsin->pid_buffer_start +
                PID_TABLE_SIZE;

        tsin->pid_buffer_aligned = (void *)
                (((uintptr_t) tsin->pid_buffer_aligned) & ~0x3ff);

        tsin->pid_buffer_busaddr = dma_map_single(fei->dev,
                                                tsin->pid_buffer_aligned,
                                                PID_TABLE_SIZE,
                                                DMA_BIDIRECTIONAL);

        if (dma_mapping_error(fei->dev, tsin->pid_buffer_busaddr)) {
                dev_err(fei->dev, "failed to map pid_bitmap\n");
                ret = -EFAULT;
                goto err_unmap;
        }

        /* manage cache so pid bitmap is visible to HW */
        dma_sync_single_for_device(fei->dev,
                                tsin->pid_buffer_busaddr,
                                PID_TABLE_SIZE,
                                DMA_TO_DEVICE);

        snprintf(tsin_pin_name, MAX_NAME, "tsin%d-%s", tsin->tsin_id,
                (tsin->serial_not_parallel ? "serial" : "parallel"));

        tsin->pstate = pinctrl_lookup_state(fei->pinctrl, tsin_pin_name);
        if (IS_ERR(tsin->pstate)) {
                dev_err(fei->dev, "%s: pinctrl_lookup_state couldn't find %s state\n"
                        , __func__, tsin_pin_name);
                ret = PTR_ERR(tsin->pstate);
                goto err_unmap;
        }

        ret = pinctrl_select_state(fei->pinctrl, tsin->pstate);

        if (ret) {
                dev_err(fei->dev, "%s: pinctrl_select_state failed\n"
                        , __func__);
                goto err_unmap;
        }

        /* Enable this input block */
        tmp = readl(fei->io + SYS_INPUT_CLKEN);
        tmp |= BIT(tsin->tsin_id);
        writel(tmp, fei->io + SYS_INPUT_CLKEN);

        if (tsin->serial_not_parallel)
                tmp |= C8SECTPFE_SERIAL_NOT_PARALLEL;

        if (tsin->invert_ts_clk)
                tmp |= C8SECTPFE_INVERT_TSCLK;

        if (tsin->async_not_sync)
                tmp |= C8SECTPFE_ASYNC_NOT_SYNC;

        tmp |= C8SECTPFE_ALIGN_BYTE_SOP | C8SECTPFE_BYTE_ENDIANNESS_MSB;

        writel(tmp, fei->io + C8SECTPFE_IB_IP_FMT_CFG(tsin->tsin_id));

        writel(C8SECTPFE_SYNC(0x9) |
                C8SECTPFE_DROP(0x9) |
                C8SECTPFE_TOKEN(0x47),
                fei->io + C8SECTPFE_IB_SYNCLCKDRP_CFG(tsin->tsin_id));

        writel(TS_PKT_SIZE, fei->io + C8SECTPFE_IB_PKT_LEN(tsin->tsin_id));

        /* Place the FIFO's at the end of the irec descriptors */

        tsin->fifo = (tsin->tsin_id * FIFO_LEN);

        writel(tsin->fifo, fei->io + C8SECTPFE_IB_BUFF_STRT(tsin->tsin_id));
        writel(tsin->fifo + FIFO_LEN - 1,
                fei->io + C8SECTPFE_IB_BUFF_END(tsin->tsin_id));

        writel(tsin->fifo, fei->io + C8SECTPFE_IB_READ_PNT(tsin->tsin_id));
        writel(tsin->fifo, fei->io + C8SECTPFE_IB_WRT_PNT(tsin->tsin_id));

        writel(tsin->pid_buffer_busaddr,
                fei->io + PIDF_BASE(tsin->tsin_id));

        dev_dbg(fei->dev, "chan=%d PIDF_BASE=0x%x pid_bus_addr=%pad\n",
                tsin->tsin_id, readl(fei->io + PIDF_BASE(tsin->tsin_id)),
                &tsin->pid_buffer_busaddr);

        /* Configure and enable HW PID filtering */

        /*
         * The PID value is created by assembling the first 8 bytes of
         * the TS packet into a 64-bit word in big-endian format. A
         * slice of that 64-bit word is taken from
         * (PID_OFFSET+PID_NUM_BITS-1) to PID_OFFSET.
         */
        tmp = (C8SECTPFE_PID_ENABLE | C8SECTPFE_PID_NUMBITS(13)
                | C8SECTPFE_PID_OFFSET(40));

        writel(tmp, fei->io + C8SECTPFE_IB_PID_SET(tsin->tsin_id));

        dev_dbg(fei->dev, "chan=%d setting wp: %d, rp: %d, buf: %d-%d\n",
                tsin->tsin_id,
                readl(fei->io + C8SECTPFE_IB_WRT_PNT(tsin->tsin_id)),
                readl(fei->io + C8SECTPFE_IB_READ_PNT(tsin->tsin_id)),
                readl(fei->io + C8SECTPFE_IB_BUFF_STRT(tsin->tsin_id)),
                readl(fei->io + C8SECTPFE_IB_BUFF_END(tsin->tsin_id)));

        /* Get base addpress of pointer record block from DMEM */
        tsin->irec = fei->io + DMA_MEMDMA_OFFSET + DMA_DMEM_OFFSET +
                        readl(fei->io + DMA_PTRREC_BASE);

        /* fill out pointer record data structure */

        /* advance pointer record block to our channel */
        tsin->irec += (tsin->tsin_id * DMA_PRDS_SIZE);

        writel(tsin->fifo, tsin->irec + DMA_PRDS_MEMBASE);

        writel(tsin->fifo + FIFO_LEN - 1, tsin->irec + DMA_PRDS_MEMTOP);

        writel((188 + 7)&~7, tsin->irec + DMA_PRDS_PKTSIZE);

        writel(0x1, tsin->irec + DMA_PRDS_TPENABLE);

        /* read/write pointers with physical bus address */

        writel(tsin->back_buffer_busaddr, tsin->irec + DMA_PRDS_BUSBASE_TP(0));

        tmp = tsin->back_buffer_busaddr + FEI_BUFFER_SIZE - 1;
        writel(tmp, tsin->irec + DMA_PRDS_BUSTOP_TP(0));

        writel(tsin->back_buffer_busaddr, tsin->irec + DMA_PRDS_BUSWP_TP(0));
        writel(tsin->back_buffer_busaddr, tsin->irec + DMA_PRDS_BUSRP_TP(0));

        /* initialize tasklet */
        tasklet_init(&tsin->tsklet, channel_swdemux_tsklet,
                (unsigned long) tsin);

        return 0;

err_unmap:
        free_input_block(fei, tsin);
        return ret;
}

static irqreturn_t c8sectpfe_error_irq_handler(int irq, void *priv)
{
        struct c8sectpfei *fei = priv;

        dev_err(fei->dev, "%s: error handling not yet implemented\n"
                , __func__);

        /*
         * TODO FIXME we should detect some error conditions here
         * and ideally so something about them!
         */

        return IRQ_HANDLED;
}

static int c8sectpfe_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *child, *np = dev->of_node;
        struct c8sectpfei *fei;
        struct resource *res;
        int ret, index = 0;
        struct channel_info *tsin;

        /* Allocate the c8sectpfei structure */
        fei = devm_kzalloc(dev, sizeof(struct c8sectpfei), GFP_KERNEL);
        if (!fei)
                return -ENOMEM;

        fei->dev = dev;

        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "c8sectpfe");
        fei->io = devm_ioremap_resource(dev, res);
        if (IS_ERR(fei->io))
                return PTR_ERR(fei->io);

        res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
                                        "c8sectpfe-ram");
        fei->sram = devm_ioremap_resource(dev, res);
        if (IS_ERR(fei->sram))
                return PTR_ERR(fei->sram);

        fei->sram_size = resource_size(res);

        fei->idle_irq = platform_get_irq_byname(pdev, "c8sectpfe-idle-irq");
        if (fei->idle_irq < 0) {
                dev_err(dev, "Can't get c8sectpfe-idle-irq\n");
                return fei->idle_irq;
        }

        fei->error_irq = platform_get_irq_byname(pdev, "c8sectpfe-error-irq");
        if (fei->error_irq < 0) {
                dev_err(dev, "Can't get c8sectpfe-error-irq\n");
                return fei->error_irq;
        }

        platform_set_drvdata(pdev, fei);

        fei->c8sectpfeclk = devm_clk_get(dev, "c8sectpfe");
        if (IS_ERR(fei->c8sectpfeclk)) {
                dev_err(dev, "c8sectpfe clk not found\n");
                return PTR_ERR(fei->c8sectpfeclk);
        }

        ret = clk_prepare_enable(fei->c8sectpfeclk);
        if (ret) {
                dev_err(dev, "Failed to enable c8sectpfe clock\n");
                return ret;
        }

        /* to save power disable all IP's (on by default) */
        writel(0, fei->io + SYS_INPUT_CLKEN);

        /* Enable memdma clock */
        writel(MEMDMAENABLE, fei->io + SYS_OTHER_CLKEN);

        /* clear internal sram */
        memset_io(fei->sram, 0x0, fei->sram_size);

        c8sectpfe_getconfig(fei);

        ret = devm_request_irq(dev, fei->idle_irq, c8sectpfe_idle_irq_handler,
                        0, "c8sectpfe-idle-irq", fei);
        if (ret) {
                dev_err(dev, "Can't register c8sectpfe-idle-irq IRQ.\n");
                goto err_clk_disable;
        }

        ret = devm_request_irq(dev, fei->error_irq,
                                c8sectpfe_error_irq_handler, 0,
                                "c8sectpfe-error-irq", fei);
        if (ret) {
                dev_err(dev, "Can't register c8sectpfe-error-irq IRQ.\n");
                goto err_clk_disable;
        }

        fei->tsin_count = of_get_child_count(np);

        if (fei->tsin_count > C8SECTPFE_MAX_TSIN_CHAN ||
                fei->tsin_count > fei->hw_stats.num_ib) {

                dev_err(dev, "More tsin declared than exist on SoC!\n");
                ret = -EINVAL;
                goto err_clk_disable;
        }

        fei->pinctrl = devm_pinctrl_get(dev);

        if (IS_ERR(fei->pinctrl)) {
                dev_err(dev, "Error getting tsin pins\n");
                ret = PTR_ERR(fei->pinctrl);
                goto err_clk_disable;
        }

        for_each_child_of_node(np, child) {
                struct device_node *i2c_bus;

                fei->channel_data[index] = devm_kzalloc(dev,
                                                sizeof(struct channel_info),
                                                GFP_KERNEL);

                if (!fei->channel_data[index]) {
                        ret = -ENOMEM;
                        goto err_clk_disable;
                }

                tsin = fei->channel_data[index];

                tsin->fei = fei;

                ret = of_property_read_u32(child, "tsin-num", &tsin->tsin_id);
                if (ret) {
                        dev_err(&pdev->dev, "No tsin_num found\n");
                        goto err_clk_disable;
                }

                /* sanity check value */
                if (tsin->tsin_id > fei->hw_stats.num_ib) {
                        dev_err(&pdev->dev,
                                "tsin-num %d specified greater than number\n\tof input block hw in SoC! (%d)",
                                tsin->tsin_id, fei->hw_stats.num_ib);
                        ret = -EINVAL;
                        goto err_clk_disable;
                }

                tsin->invert_ts_clk = of_property_read_bool(child,
                                                        "invert-ts-clk");

                tsin->serial_not_parallel = of_property_read_bool(child,
                                                        "serial-not-parallel");

                tsin->async_not_sync = of_property_read_bool(child,
                                                        "async-not-sync");

                ret = of_property_read_u32(child, "dvb-card",
                                        &tsin->dvb_card);
                if (ret) {
                        dev_err(&pdev->dev, "No dvb-card found\n");
                        goto err_clk_disable;
                }

                i2c_bus = of_parse_phandle(child, "i2c-bus", 0);
                if (!i2c_bus) {
                        dev_err(&pdev->dev, "No i2c-bus found\n");
                        ret = -ENODEV;
                        goto err_clk_disable;
                }
                tsin->i2c_adapter =
                        of_find_i2c_adapter_by_node(i2c_bus);
                if (!tsin->i2c_adapter) {
                        dev_err(&pdev->dev, "No i2c adapter found\n");
                        of_node_put(i2c_bus);
                        ret = -ENODEV;
                        goto err_clk_disable;
                }
                of_node_put(i2c_bus);

                tsin->rst_gpio = of_get_named_gpio(child, "reset-gpios", 0);

                ret = gpio_is_valid(tsin->rst_gpio);
                if (!ret) {
                        dev_err(dev,
                                "reset gpio for tsin%d not valid (gpio=%d)\n",
                                tsin->tsin_id, tsin->rst_gpio);
                        goto err_clk_disable;
                }

                ret = devm_gpio_request_one(dev, tsin->rst_gpio,
                                        GPIOF_OUT_INIT_LOW, "NIM reset");
                if (ret && ret != -EBUSY) {
                        dev_err(dev, "Can't request tsin%d reset gpio\n"
                                , fei->channel_data[index]->tsin_id);
                        goto err_clk_disable;
                }

                if (!ret) {
                        /* toggle reset lines */
                        gpio_direction_output(tsin->rst_gpio, 0);
                        usleep_range(3500, 5000);
                        gpio_direction_output(tsin->rst_gpio, 1);
                        usleep_range(3000, 5000);
                }

                tsin->demux_mapping = index;

                dev_dbg(fei->dev,
                        "channel=%p n=%d tsin_num=%d, invert-ts-clk=%d\n\tserial-not-parallel=%d pkt-clk-valid=%d dvb-card=%d\n",
                        fei->channel_data[index], index,
                        tsin->tsin_id, tsin->invert_ts_clk,
                        tsin->serial_not_parallel, tsin->async_not_sync,
                        tsin->dvb_card);

                index++;
        }

        /* Setup timer interrupt */
        timer_setup(&fei->timer, c8sectpfe_timer_interrupt, 0);

        mutex_init(&fei->lock);

        /* Get the configuration information about the tuners */
        ret = c8sectpfe_tuner_register_frontend(&fei->c8sectpfe[0],
                                        (void *)fei,
                                        c8sectpfe_start_feed,
                                        c8sectpfe_stop_feed);
        if (ret) {
                dev_err(dev, "c8sectpfe_tuner_register_frontend failed (%d)\n",
                        ret);
                goto err_clk_disable;
        }

        c8sectpfe_debugfs_init(fei);

        return 0;

err_clk_disable:
        clk_disable_unprepare(fei->c8sectpfeclk);
        return ret;
}

static int c8sectpfe_remove(struct platform_device *pdev)
{
        struct c8sectpfei *fei = platform_get_drvdata(pdev);
        struct channel_info *channel;
        int i;

        wait_for_completion(&fei->fw_ack);

        c8sectpfe_tuner_unregister_frontend(fei->c8sectpfe[0], fei);

        /*
         * Now loop through and un-configure each of the InputBlock resources
         */
        for (i = 0; i < fei->tsin_count; i++) {
                channel = fei->channel_data[i];
                free_input_block(fei, channel);
        }

        c8sectpfe_debugfs_exit(fei);

        dev_info(fei->dev, "Stopping memdma SLIM core\n");
        if (readl(fei->io + DMA_CPU_RUN))
                writel(0x0,  fei->io + DMA_CPU_RUN);

        /* unclock all internal IP's */
        if (readl(fei->io + SYS_INPUT_CLKEN))
                writel(0, fei->io + SYS_INPUT_CLKEN);

        if (readl(fei->io + SYS_OTHER_CLKEN))
                writel(0, fei->io + SYS_OTHER_CLKEN);

        if (fei->c8sectpfeclk)
                clk_disable_unprepare(fei->c8sectpfeclk);

        return 0;
}


static int configure_channels(struct c8sectpfei *fei)
{
        int index = 0, ret;
        struct channel_info *tsin;
        struct device_node *child, *np = fei->dev->of_node;

        /* iterate round each tsin and configure memdma descriptor and IB hw */
        for_each_child_of_node(np, child) {

                tsin = fei->channel_data[index];

                ret = configure_memdma_and_inputblock(fei,
                                                fei->channel_data[index]);

                if (ret) {
                        dev_err(fei->dev,
                                "configure_memdma_and_inputblock failed\n");
                        goto err_unmap;
                }
                index++;
        }

        return 0;

err_unmap:
        for (index = 0; index < fei->tsin_count; index++) {
                tsin = fei->channel_data[index];
                free_input_block(fei, tsin);
        }
        return ret;
}

static int
c8sectpfe_elf_sanity_check(struct c8sectpfei *fei, const struct firmware *fw)
{
        struct elf32_hdr *ehdr;
        char class;

        if (!fw) {
                dev_err(fei->dev, "failed to load %s\n", FIRMWARE_MEMDMA);
                return -EINVAL;
        }

        if (fw->size < sizeof(struct elf32_hdr)) {
                dev_err(fei->dev, "Image is too small\n");
                return -EINVAL;
        }

        ehdr = (struct elf32_hdr *)fw->data;

        /* We only support ELF32 at this point */
        class = ehdr->e_ident[EI_CLASS];
        if (class != ELFCLASS32) {
                dev_err(fei->dev, "Unsupported class: %d\n", class);
                return -EINVAL;
        }

        if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
                dev_err(fei->dev, "Unsupported firmware endianness\n");
                return -EINVAL;
        }

        if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) {
                dev_err(fei->dev, "Image is too small\n");
                return -EINVAL;
        }

        if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
                dev_err(fei->dev, "Image is corrupted (bad magic)\n");
                return -EINVAL;
        }

        /* Check ELF magic */
        ehdr = (Elf32_Ehdr *)fw->data;
        if (ehdr->e_ident[EI_MAG0] != ELFMAG0 ||
            ehdr->e_ident[EI_MAG1] != ELFMAG1 ||
            ehdr->e_ident[EI_MAG2] != ELFMAG2 ||
            ehdr->e_ident[EI_MAG3] != ELFMAG3) {
                dev_err(fei->dev, "Invalid ELF magic\n");
                return -EINVAL;
        }

        if (ehdr->e_type != ET_EXEC) {
                dev_err(fei->dev, "Unsupported ELF header type\n");
                return -EINVAL;
        }

        if (ehdr->e_phoff > fw->size) {
                dev_err(fei->dev, "Firmware size is too small\n");
                return -EINVAL;
        }

        return 0;
}


static void load_imem_segment(struct c8sectpfei *fei, Elf32_Phdr *phdr,
                        const struct firmware *fw, u8 __iomem *dest,
                        int seg_num)
{
        const u8 *imem_src = fw->data + phdr->p_offset;
        int i;

        /*
         * For IMEM segments, the segment contains 24-bit
         * instructions which must be padded to 32-bit
         * instructions before being written. The written
         * segment is padded with NOP instructions.
         */

        dev_dbg(fei->dev,
                "Loading IMEM segment %d 0x%08x\n\t (0x%x bytes) -> 0x%p (0x%x bytes)\n",
seg_num,
                phdr->p_paddr, phdr->p_filesz,
                dest, phdr->p_memsz + phdr->p_memsz / 3);

        for (i = 0; i < phdr->p_filesz; i++) {

                writeb(readb((void __iomem *)imem_src), (void __iomem *)dest);

                /* Every 3 bytes, add an additional
                 * padding zero in destination */
                if (i % 3 == 2) {
                        dest++;
                        writeb(0x00, (void __iomem *)dest);
                }

                dest++;
                imem_src++;
        }
}

static void load_dmem_segment(struct c8sectpfei *fei, Elf32_Phdr *phdr,
                        const struct firmware *fw, u8 __iomem *dst, int seg_num)
{
        /*
         * For DMEM segments copy the segment data from the ELF
         * file and pad segment with zeroes
         */

        dev_dbg(fei->dev,
                "Loading DMEM segment %d 0x%08x\n\t(0x%x bytes) -> 0x%p (0x%x bytes)\n",
                seg_num, phdr->p_paddr, phdr->p_filesz,
                dst, phdr->p_memsz);

        memcpy((void __force *)dst, (void *)fw->data + phdr->p_offset,
                phdr->p_filesz);

        memset((void __force *)dst + phdr->p_filesz, 0,
                phdr->p_memsz - phdr->p_filesz);
}

static int load_slim_core_fw(const struct firmware *fw, struct c8sectpfei *fei)
{
        Elf32_Ehdr *ehdr;
        Elf32_Phdr *phdr;
        u8 __iomem *dst;
        int err = 0, i;

        if (!fw || !fei)
                return -EINVAL;

        ehdr = (Elf32_Ehdr *)fw->data;
        phdr = (Elf32_Phdr *)(fw->data + ehdr->e_phoff);

        /* go through the available ELF segments */
        for (i = 0; i < ehdr->e_phnum; i++, phdr++) {

                /* Only consider LOAD segments */
                if (phdr->p_type != PT_LOAD)
                        continue;

                /*
                 * Check segment is contained within the fw->data buffer
                 */
                if (phdr->p_offset + phdr->p_filesz > fw->size) {
                        dev_err(fei->dev,
                                "Segment %d is outside of firmware file\n", i);
                        err = -EINVAL;
                        break;
                }

                /*
                 * MEMDMA IMEM has executable flag set, otherwise load
                 * this segment into DMEM.
                 *
                 */

                if (phdr->p_flags & PF_X) {
                        dst = (u8 __iomem *) fei->io + DMA_MEMDMA_IMEM;
                        /*
                         * The Slim ELF file uses 32-bit word addressing for
                         * load offsets.
                         */
                        dst += (phdr->p_paddr & 0xFFFFF) * sizeof(unsigned int);
                        load_imem_segment(fei, phdr, fw, dst, i);
                } else {
                        dst = (u8 __iomem *) fei->io + DMA_MEMDMA_DMEM;
                        /*
                         * The Slim ELF file uses 32-bit word addressing for
                         * load offsets.
                         */
                        dst += (phdr->p_paddr & 0xFFFFF) * sizeof(unsigned int);
                        load_dmem_segment(fei, phdr, fw, dst, i);
                }
        }

        release_firmware(fw);
        return err;
}

static int load_c8sectpfe_fw(struct c8sectpfei *fei)
{
        const struct firmware *fw;
        int err;

        dev_info(fei->dev, "Loading firmware: %s\n", FIRMWARE_MEMDMA);

        err = request_firmware(&fw, FIRMWARE_MEMDMA, fei->dev);
        if (err)
                return err;

        err = c8sectpfe_elf_sanity_check(fei, fw);
        if (err) {
                dev_err(fei->dev, "c8sectpfe_elf_sanity_check failed err=(%d)\n"
                        , err);
                release_firmware(fw);
                return err;
        }

        err = load_slim_core_fw(fw, fei);
        if (err) {
                dev_err(fei->dev, "load_slim_core_fw failed err=(%d)\n", err);
                return err;
        }

        /* now the firmware is loaded configure the input blocks */
        err = configure_channels(fei);
        if (err) {
                dev_err(fei->dev, "configure_channels failed err=(%d)\n", err);
                return err;
        }

        /*
         * STBus target port can access IMEM and DMEM ports
         * without waiting for CPU
         */
        writel(0x1, fei->io + DMA_PER_STBUS_SYNC);

        dev_info(fei->dev, "Boot the memdma SLIM core\n");
        writel(0x1,  fei->io + DMA_CPU_RUN);

        atomic_set(&fei->fw_loaded, 1);

        return 0;
}

static const struct of_device_id c8sectpfe_match[] = {
        { .compatible = "st,stih407-c8sectpfe" },
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, c8sectpfe_match);

static struct platform_driver c8sectpfe_driver = {
        .driver = {
                .name = "c8sectpfe",
                .of_match_table = of_match_ptr(c8sectpfe_match),
        },
        .probe  = c8sectpfe_probe,
        .remove = c8sectpfe_remove,
};

module_platform_driver(c8sectpfe_driver);

MODULE_AUTHOR("Peter Bennett <peter.bennett@st.com>");
MODULE_AUTHOR("Peter Griffin <peter.griffin@linaro.org>");
MODULE_DESCRIPTION("C8SECTPFE STi DVB Driver");
MODULE_LICENSE("GPL");