/*
 *  GSC3280 SoC SPI controller driver
 *
 *  Copyright (C) 2013 BLX IC Design Corp.,Ltd.
 *  Author: Davied, apple_guet@126.com
 *  Modify by: lufei, lufei@china-cpu.com 
 *
 */
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/highmem.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/spi/gsc3280_spi.h>
#include <linux/io.h>
#include <linux/scatterlist.h>
#include <gsc3280/gpio.h>
#include <asm/clock.h>
#include <gsc3280/gsc3280_regs.h>

#ifdef CONFIG_GSC3280_SPI_DEBUG
#define DBG(msg...) do { \
		printk(KERN_INFO msg); \
	} while (0)
#else
#define DBG(msg...)	do { } while(0)
#endif

#define START_STATE			((void *)0)
#define RUNNING_STATE		((void *)1)
#define DONE_STATE			((void *)2)
#define ERROR_STATE		((void *)-1)

#define MRST_SPI_DEASSERT	0
#define MRST_SPI_ASSERT	1

#define GSC_SPI_ENABLE		0x01
#define GSC_SPI_DISABLE		0x00

/* Slave spi_dev related */
struct chip_data {
	u8 n_bytes;		/* current is a 1/2/4 byte op */
	u8 cs_type;		/* 0: chip cs, 1: gpio cs */
	u8 cs_value;		/* chip select value */
	u8 lsb_flg;		/* 1:LSB, 0: MSB */
	u8 bits_per_word;
	
	u16 cr;
	u16 clk_div;		/* baud rate divider, reg value */
	u32 speed_hz;	/* baud rate */
	u32 pin_cs[3];	/* chip select pin */
	u32 pin_cnt;

	u8 poll_mode;	/* 1 means use poll mode */
#ifdef CONFIG_GSC3280_SPI_DMA
	u8 enable_dma;
	u32 dma_width;
#endif
};

struct gsc3280_spi;
#ifdef CONFIG_GSC3280_SPI_DMA

//#include <linux/gsc_dmac.h>
#include <linux/gsc3280_dma.h>

struct gsc3280_spi_dma_ops {
	int (*dma_init)(struct gsc3280_spi *gscs);
	void (*dma_exit)(struct gsc3280_spi *gscs);
	int (*dma_transfer)(struct gsc3280_spi *gscs, int cs_change);
};

#if 0
struct gsc3280_spi_dma_platform_data {
        struct gsc3280_dma_slave      dmas_tx;
        struct gsc3280_dma_slave      dmas_rx;
};
#endif
#endif

typedef enum {
	GSC_SPI_QUEUE_STOP = 0x00,
	GSC_SPI_QUEUE_RUN,
} spi_queue_state_e;

struct gsc3280_spi {
	u8 n_bytes;	//current is a 1 or 2 bytes op
	u8 max_bits_per_word;	//maxim is 16b
	u8 bus_num;
	u8 num_cs;		//supported slave numbers
	u8 busy;
	int cs_change;
	int irq;
	u32 fifo_len;	//depth of the FIFO buffer
	u32 max_freq;	//max bus freq supported
	size_t len;

	void	*tx;		//current tx point
	void	*tx_end;
	void	*rx;		//current rx point
	void	*rx_end;
	
	struct clk *clk;
	spinlock_t slock;
	void __iomem *regs;
	struct list_head queue;	//work queue
	struct spi_master *master;
	struct spi_message *cur_msg;
	struct spi_transfer *cur_transfer;
	struct chip_data *cur_chip;
	struct chip_data *prev_chip;
	struct workqueue_struct *workqueue;	/* Driver message queue */
	struct work_struct	pump_messages;
	spi_queue_state_e queue_state;
	struct tasklet_struct pump_transfers;	/* Message Transfer pump */
	irqreturn_t             (*transfer_handler)(struct gsc3280_spi *gscs);

#ifdef CONFIG_GSC3280_SPI_DMA
	u32 dma_width;
	int dma_mapped;
	dma_addr_t rx_dma;
	dma_addr_t tx_dma;
	size_t rx_map_len;
	size_t tx_map_len;
	int dma_inited;
	unsigned long paddr;
	struct dma_chan *txchan;
	struct scatterlist tx_sgl;
	struct dma_chan *rxchan;
	struct scatterlist rx_sgl;
	int dma_chan_done;
	struct device *dma_dev;
	dma_addr_t dma_addr; /* phy address of the Data register */
	struct gsc3280_spi_dma_ops *dma_ops;
	void *dma_priv; /* platform relate info */
	struct pci_dev *dmac;
#endif
	
#ifdef CONFIG_DEBUG_FS
	struct dentry *debugfs;
#endif
};

static inline void gsc3280_spi_chip_sel(struct gsc3280_spi *gscs, u16 cs)
{
	writel(cs, gscs->regs + GSC_SPI_CS);
}

/* Disable IRQ bits */
static inline void gsc3280_spi_mask_intr(struct gsc3280_spi *gscs, u32 mask)
{
	u32 new_mask = 0;

	if(gscs->irq == 14)
		new_mask = readl(gscs->regs + GSC_SPI_ISR) | mask;
	else
		new_mask = readl(gscs->regs + GSC_SPI_IMSR) | mask;
	writel(new_mask, gscs->regs + GSC_SPI_IMSR);
}

/* Enable IRQ bits */
static inline void gsc3280_spi_umask_intr(struct gsc3280_spi *gscs, u32 mask)
{
	u32 new_mask = 0;

	if(gscs->irq == 14)
		new_mask = readl(gscs->regs + GSC_SPI_ISR) & ~mask;
	else
		new_mask = readl(gscs->regs + GSC_SPI_IMSR) & ~mask;
	writel(new_mask, gscs->regs + GSC_SPI_IMSR);
}

static inline void gsc3280_enable_spi(struct gsc3280_spi *gscs, int enable)
{	
	u32 cr = 0;

	if(enable)
		cr = readl(gscs->regs + GSC_SPI_CTRL)  | (GSC_SPI_CTL_EN);
	else
		cr = readl(gscs->regs + GSC_SPI_CTRL)  & ~(GSC_SPI_CTL_EN);
	writel(cr, gscs->regs + GSC_SPI_CTRL);
}

static inline void gsc3280_spi_clr_fifo(struct gsc3280_spi *gscs)
{
	u32 cr = GSC_SPI_CTL_CLR;
	cr |= readl(gscs->regs + GSC_SPI_CTRL);
	writel(cr, gscs->regs + GSC_SPI_CTRL);
}

static void *gsc3280_spi_next_transfer(struct gsc3280_spi *gscs)
{
	struct spi_message *msg = gscs->cur_msg;
	struct spi_transfer *trans = gscs->cur_transfer;

	if (trans->transfer_list.next != &msg->transfers) {
		gscs->cur_transfer = list_entry(trans->transfer_list.next, struct spi_transfer, transfer_list);
		return RUNNING_STATE;
	} else
		return DONE_STATE;
}

/* Caller already set message->status; dma and pio irqs are blocked */
static void gsc3280_spi_giveback(struct gsc3280_spi *gscs)
{
	struct spi_message *msg;
	unsigned long flags = 0;
	int i;
	int cs_type = gscs->cur_chip->cs_type;
	int cs_value = gscs->cur_chip->cs_value;
	int pin_cnt = gscs->cur_chip->pin_cnt;
	int *pin_cs = gscs->cur_chip->pin_cs;
	
	spin_lock_irqsave(&gscs->slock, flags);
	msg = gscs->cur_msg;
	gscs->cur_msg = NULL;
	gscs->cur_transfer = NULL;
	gscs->prev_chip = gscs->cur_chip;
	gscs->cur_chip = NULL;
#ifdef CONFIG_GSC3280_SPI_DMA
	gscs->dma_mapped = 0;
#endif
	queue_work(gscs->workqueue, &gscs->pump_messages);
	spin_unlock_irqrestore(&gscs->slock, flags);

	DBG("gsc3280_spi_giveback\n");
	if (cs_type == 0)		//chip cs
		writel(1, gscs->regs + GSC_SPI_CS);
	else{				//io cs
		for(i=0;i<pin_cnt;i++)
			gpio_set_value(pin_cs[i],~((cs_value>>(i+1))&0x1));
	}
	msg->state = NULL;
	if (msg->complete)
		msg->complete(msg->context);
}

static void gsc3280_spi_xfer_done(struct gsc3280_spi *gscs)
{
	/* Update total byte transferred return count actual bytes read */
	gscs->cur_msg->actual_length += gscs->len;
	/* Move to next transfer */
	gscs->cur_msg->state = gsc3280_spi_next_transfer(gscs);
	if (gscs->cur_msg->state == DONE_STATE) {
		/* Handle end of message */
		gscs->cur_msg->status = 0;
		gsc3280_spi_giveback(gscs);
	} else {
		tasklet_schedule(&gscs->pump_transfers);
	}
}

#ifdef CONFIG_GSC3280_SPI_DMA
#if 0
static struct gsc3280_spi_dma_platform_data spi_platform_data = {                                              
        .dmas_tx.dma_dev = &(gsc3280_dmac_device.dev),                                       
        .dmas_rx.dma_dev = &(gsc3280_dmac_device.dev),                                       
};
#endif
/* Note: first step is the protocol driver prepares a dma-capable memory, and this func just need translate
	the virt addr to physical */
static int map_dma_buffers(struct gsc3280_spi *gscs)
{
	if (!gscs->cur_msg->is_dma_mapped || !gscs->dma_inited || !gscs->cur_chip->enable_dma
		|| !gscs->dma_ops) {
		return 0;
	}
	if (gscs->cur_transfer->tx_dma)
		gscs->tx_dma = gscs->cur_transfer->tx_dma;
	if (gscs->cur_transfer->rx_dma)
		gscs->rx_dma = gscs->cur_transfer->rx_dma;
	return 1;
}

static bool gsc3280_spi_dma_chan_filter(struct dma_chan *chan, void *param)
{
        struct gsc3280_dma_slave *gscs = param;
        return (gscs->dma_dev == chan->device->dev);
}

static int gscs_dma_init(struct gsc3280_spi *gscs)
{
        struct gsc3280_spi_dma_platform_data *hsd = gscs->dma_priv;
        //struct gsc_dma_slave *rxs, *txs;
        struct gsc3280_dma_slave *rxs, *txs;
        dma_cap_mask_t mask;

        dma_cap_zero(mask);
        dma_cap_set(DMA_SLAVE, mask);
        /* 1. Init rx channel */
        rxs = &hsd->dmas_rx;
	rxs->rx_reg = gscs->dma_addr;
	rxs->reg_width = 0;	
	rxs->cfg_hi =  0x584;
	rxs->cfg_lo = 0x640;
	rxs->dst_msize = 0;
	rxs->src_msize = 0;
	rxs->dst_master = 1;
	rxs->src_master = 0;
	rxs->fc = 2; 		
        gscs->rxchan = dma_request_channel(mask, gsc3280_spi_dma_chan_filter, rxs);
        if (!gscs->rxchan)
                goto err_exit;
        gscs->rxchan->private = rxs;
        /* 2. Init tx channel */
        txs = &hsd->dmas_tx;
	txs->tx_reg = gscs->dma_addr;
	txs->reg_width = 0;	
	txs->cfg_hi =  0x5004;
	txs->cfg_lo = 0xa20;
	txs->src_msize = 0;
	txs->dst_msize = 0;
	txs->dst_master = 0;
	txs->src_master = 1;
	txs->fc = 1; 		
        gscs->txchan = dma_request_channel(mask, gsc3280_spi_dma_chan_filter, txs);
        if (!gscs->txchan)
                goto free_rxchan;
        gscs->txchan->private = txs;
        gscs->dma_inited = 1;
        return 0;
free_rxchan:
        gsc3280_dma_single_free(gscs->rxchan);
err_exit:
        return -1;
}
static void gscs_dma_exit(struct gsc3280_spi *gscs)
{
        gsc3280_dma_single_free(gscs->txchan);
        gsc3280_dma_single_free(gscs->rxchan);
}

static void gsc3280_spi_dma_done(void *arg)
{
        struct gsc3280_spi *gscs = arg;

        if (++gscs->dma_chan_done != 2)
                return;
	if (gscs->dma_mapped)   
                gscs->dma_ops->dma_exit(gscs);
        gsc3280_spi_xfer_done(gscs);
}

static int gscs_dma_transfer(struct gsc3280_spi *gscs, int cs_change)
{
	//struct he_cyclic_desc *txdesc = NULL,*rxdesc = NULL;
	struct gsc3280_cyclic_desc *txdesc = NULL,*rxdesc = NULL;
        struct dma_chan *txchan, *rxchan;
        u16 dma_ctrl = 0;

        /* 1. setup DMA related registers */
//        if (cs_change) {
		gsc3280_spi_chip_sel(gscs, 0x1);
//              gsc3280_enable_spi(gscs, 0);
                if (gscs->tx_dma)
                        dma_ctrl |= 1<<7;
                if (gscs->rx_dma)
                        dma_ctrl |= 1<<6;
		dma_ctrl |= readw(gscs->regs + GSC_SPI_CTRL);
		   writew(dma_ctrl, gscs->regs + GSC_SPI_CTRL);
//             	gsc3280_enable_spi(gscs, 1);
		gsc3280_spi_chip_sel(gscs, 0x0);
//        }
        gscs->dma_chan_done = 0;
        txchan = gscs->txchan;
        rxchan = gscs->rxchan;
        /* 2. Prepare the TX dma transfer */
	//txdesc = gsc_dma_single_prep(txchan, gscs->tx_dma, gscs->len, DMA_TO_DEVICE);	
	txdesc = gsc3280_dma_single_prep(txchan, gscs->tx_dma, gscs->len, DMA_TO_DEVICE);	
	txdesc->period_callback = &gsc3280_spi_dma_done;		
	txdesc->period_callback_param = gscs;
        /* 3. Prepare the RX dma transfer */
	//rxdesc = gsc_dma_single_prep(rxchan, gscs->rx_dma, gscs->len, DMA_FROM_DEVICE);		
	rxdesc = gsc3280_dma_single_prep(rxchan, gscs->rx_dma, gscs->len, DMA_FROM_DEVICE);		
	rxdesc->period_callback = &gsc3280_spi_dma_done;
	rxdesc->period_callback_param = gscs;
	/* 4. submit */
        /* rx must be started before tx due to spi instinct */
	//gsc_dma_single_start(rxchan);
	gsc3280_dma_single_start(rxchan);
	//gsc_dma_single_start(txchan);
	gsc3280_dma_single_start(txchan);
        return 0;
}

static struct gsc3280_spi_dma_ops gscs_dma_ops = {
        .dma_init       = gscs_dma_init,
        .dma_exit       = gscs_dma_exit,
        .dma_transfer   = gscs_dma_transfer,
};

#endif

/* Return the max entries we should read out of rx fifo */
static inline u32 gsc3280_spi_rx_max(struct gsc3280_spi *gscs)
{
	u32 rx_left = (gscs->rx_end - gscs->rx) / gscs->n_bytes;
	return min(rx_left, (u32)readw(gscs->regs + GSC_SPI_RXFLR));
}
/* Return the max entries we can fill into tx fifo */
static inline u32 gsc3280_spi_tx_max(struct gsc3280_spi *gscs)
{
	u32 tx_left,tx_room,rxtx_gap;

	tx_left = (gscs->tx_end - gscs->tx) / gscs->n_bytes;
	tx_room = gscs->fifo_len - readw(gscs->regs + GSC_SPI_TXFLR);
	rxtx_gap =  ((gscs->rx_end - gscs->rx) - (gscs->tx_end - gscs->tx))
			/ gscs->n_bytes;
	return min3(tx_left, tx_room,(u32)(gscs->fifo_len - rxtx_gap));
}

static void gsc3280_reader(struct gsc3280_spi *gscs)
{
	u32 max = gsc3280_spi_rx_max(gscs);
        u16 rxw;

        while (max--) {
		rxw = readl(gscs->regs + GSC_SPI_DA_S);
		DBG("rxw = 0x%x\n\n", rxw);
                /* Care rx only if the transfer's original "rx" is not null */
                if (gscs->rx_end - gscs->len) {
                        if (gscs->n_bytes == 1)
                                *(u8 *)(gscs->rx) = rxw;
                        else
                                *(u16 *)(gscs->rx) = rxw;
                }
                gscs->rx += gscs->n_bytes;
        }
}

static void gsc3280_writer(struct gsc3280_spi *gscs)
{
	u32 max = gsc3280_spi_tx_max(gscs);
        u16 txw = 0;

        while (max--) {
                /* Set the tx word if the transfer's original "tx" is not null */
                if (gscs->tx_end - gscs->len) {
                        if (gscs->n_bytes == 1)
                                txw = *(u8 *)(gscs->tx);
                        else
                                txw = *(u16 *)(gscs->tx);
                }
		if(gscs->irq == 14)
			udelay(1);
		DBG("txw = 0x%x\n\n", txw);
		writel(txw, gscs->regs + GSC_SPI_DA_S);
                gscs->tx += gscs->n_bytes;
        }
}

/* Must be called inside pump_transfers() */
static void gsc3280_spi_poll_transfer(struct gsc3280_spi *gscs)
{
	do {
		gsc3280_writer(gscs);
		gsc3280_reader(gscs);
		cpu_relax();
	} while (gscs->rx_end > gscs->rx);
	gsc3280_spi_xfer_done(gscs);
}

static void int_error_stop(struct gsc3280_spi *gscs, const char *msg)
{
        /* Stop the hw */
	gsc3280_enable_spi(gscs, GSC_SPI_DISABLE);
	gsc3280_spi_clr_fifo(gscs);
        dev_err(&gscs->master->dev, "%s\n", msg);
        gscs->cur_msg->state = ERROR_STATE;
        tasklet_schedule(&gscs->pump_transfers);
}

static irqreturn_t interrupt_transfer(struct gsc3280_spi *gscs)
{
	u16 irq_status ;
	if(gscs->irq == 14)
		irq_status = readw(gscs->regs + GSC_SPI_IMSR);
	else
		irq_status = readw(gscs->regs + GSC_SPI_ISR);
	/* Error handling */
	if (irq_status  & (SPI_INT_TX_H_OVER | SPI_INT_RX_L_OVER | SPI_INT_RX_H_OVER)){
		printk(KERN_INFO "irq_status=0x%x\n",irq_status);
		writew(0xe, gscs->regs + GSC_SPI_ISR);
	        int_error_stop(gscs, "interrupt_transfer: fifo overrun/underrun");
        	return IRQ_HANDLED;
	}
	gsc3280_reader(gscs);
	if (gscs->rx_end == gscs->rx) {
		gsc3280_spi_mask_intr(gscs, SPI_INT_TX_EMPTY);
	        gsc3280_spi_xfer_done(gscs);
        	return IRQ_HANDLED;
	}	
	if (irq_status & SPI_INT_TX_EMPTY) {
		gsc3280_spi_mask_intr(gscs, SPI_INT_TX_EMPTY);
	        gsc3280_writer(gscs);
        	/* Enable TX irq always, it will be disabled when RX finished */
		gsc3280_spi_umask_intr(gscs, SPI_INT_TX_EMPTY);
	}

	return IRQ_HANDLED;
}

/* this is transfer message function */
static irqreturn_t gsc3280_spi_irq(int irq, void *dev_id)
{
	struct gsc3280_spi *gscs = dev_id;
	u16 irq_status;
	if(irq == 14)
		irq_status = readw(gscs->regs + GSC_SPI_IMSR);
	else
		irq_status = readw(gscs->regs + GSC_SPI_ISR);

	if (!irq_status)
        	return IRQ_NONE;
	if (!gscs->cur_msg) {
		gsc3280_spi_mask_intr(gscs, SPI_INT_TX_EMPTY);
		return IRQ_HANDLED;
	}

	return gscs->transfer_handler(gscs);
}

/* when call this function,the cur_msg is the new msg */
static void gsc3280_spi_pump_transfers(unsigned long data)
{
	struct gsc3280_spi *gscs = (struct gsc3280_spi *)data;
	int clk_div = 0;
	u32 imask = 0, cr = 0;
	struct spi_message *message = NULL;
	struct spi_transfer *transfer = NULL;
	struct spi_transfer *previous = NULL;
	struct spi_device *spi = NULL;
	struct chip_data *chip = NULL;

	/* Get current state information */
	message = gscs->cur_msg;
	transfer = gscs->cur_transfer;
	chip = gscs->cur_chip;
	spi = message->spi;

	DBG("gsc3280_spi_pump_transfers\n");
	if (message->state == ERROR_STATE) {
		DBG("!!!!pump_transfers:cur msg state error!\n");
		message->status = -EIO;
		goto early_exit;
	}
	/* Handle end of message */
	if (message->state == DONE_STATE) {
		message->status = 0;
		goto early_exit;
	}
	/* Delay if requested at end of transfer*/
	if (message->state == RUNNING_STATE) {
		previous = list_entry(transfer->transfer_list.prev, struct spi_transfer, transfer_list);
		if (previous->delay_usecs)
			udelay(previous->delay_usecs);
	}

#ifdef CONFIG_GSC3280_SPI_DMA
	gscs->dma_width = chip->dma_width;
	gscs->rx_dma = transfer->rx_dma;
	gscs->tx_dma = transfer->tx_dma;
#endif

	gscs->tx = (void *)transfer->tx_buf;
	gscs->tx_end = gscs->tx + transfer->len;
	gscs->rx = transfer->rx_buf;
	gscs->rx_end = gscs->rx + transfer->len;
	gscs->cs_change = transfer->cs_change;
	gscs->len = transfer->len;

	/* Handle per transfer options for bpw and speed */
	if (transfer->speed_hz) {
		if (transfer->speed_hz != chip->speed_hz) {
			if (transfer->speed_hz > (gscs->max_freq/2)) {
				printk(KERN_ERR "SPI: unsupported freq: %dHz\n", transfer->speed_hz);
				message->status = -EIO;
				return;
			} else
				chip->speed_hz = transfer->speed_hz;
		}

		clk_div = gscs->max_freq / chip->speed_hz;
		if((gscs->max_freq%chip->speed_hz)>0)
			clk_div +=1;
		if(clk_div%2)
			clk_div = clk_div/2;
		else
			clk_div = (clk_div/2) -1;
		chip->clk_div = (u16)clk_div;
		writel(chip->clk_div, gscs->regs + GSC_SPI_SEABAUR);
	}
	if (transfer->bits_per_word) {
		switch (transfer->bits_per_word) {
		case 8:
		case 16:
			gscs->n_bytes = transfer->bits_per_word >> 3;
#ifdef CONFIG_GSC3280_SPI_DMA
			gscs->dma_width = gscs->n_bytes;
#endif
			break;
		default:
			printk(KERN_ERR "SPI: unsupported bits:" "%db\n", transfer->bits_per_word);
			message->status = -EIO;
			return;
		}
	}

	message->state = RUNNING_STATE;
	
	/* Interrupt mode we only need set the TXEI IRQ, as TX/RX always happen syncronizely */
	if (!chip->poll_mode) {
		gscs->transfer_handler = interrupt_transfer;
		imask |= SPI_INT_TX_H_OVER | SPI_INT_RX_L_OVER | SPI_INT_RX_H_OVER | SPI_INT_RX_FULL ;

		if (gscs->tx != NULL) {
			imask |= SPI_INT_TX_EMPTY;
		}
		gsc3280_spi_umask_intr(gscs, imask);
	}
	cr = chip->cr | GSC_SPI_CTL_EN;
	writel(cr, gscs->regs + GSC_SPI_CTRL);	/* enable spi */

#ifdef CONFIG_GSC3280_SPI_DMA
	/* Check if current transfer is a DMA transaction */
	gscs->dma_mapped = map_dma_buffers(gscs);
	if (gscs->dma_mapped)
		//gscs->dma_ops->dma_transfer(gscs, cs_change);
		gscs->dma_ops->dma_transfer(gscs, gscs->cs_change);
#endif
	if (chip->poll_mode)
		gsc3280_spi_poll_transfer(gscs);
	
	return;
	
early_exit:
	gsc3280_spi_giveback(gscs);
	return;
}

/* 
  * when call this function, no msg transfering 
  * deal one msg when call this funciton once.
  *
  */
static void gsc3280_spi_pump_messages(struct work_struct *work)
{
	unsigned long flags = 0;
	int i;
	struct gsc3280_spi *gscs = container_of(work, struct gsc3280_spi, pump_messages);

	DBG("####gsc3280_spi_pump_messages####\n");
	spin_lock_irqsave(&gscs->slock, flags);
	if (list_empty(&gscs->queue) || (gscs->queue_state == GSC_SPI_QUEUE_STOP)) {
		DBG("msg is finished!\n");
                spin_unlock_irqrestore(&gscs->slock, flags);
		gscs->busy = 0;
		return;
	}
	/* Make sure we are not already running a message */
        if (gscs->cur_msg) {
                spin_unlock_irqrestore(&gscs->slock, flags);
                return;
        }
	gscs->cur_msg = list_entry(gscs->queue.next, struct spi_message, queue);
	if (!gscs->cur_msg) {
		spin_unlock_irqrestore(&gscs->slock, flags);
		DBG("!!!!gsc3280_spi_pump_messages: current no msg!\n");
		return;
	}
	list_del_init(&gscs->cur_msg->queue);
	gscs->cur_msg->state = START_STATE;
	gscs->cur_chip = spi_get_ctldata(gscs->cur_msg->spi);
	gscs->n_bytes = gscs->cur_chip->n_bytes;
	if (gscs->cur_chip->cs_type == 0)		//chip cs
			writel(0, gscs->regs + GSC_SPI_CS);
	else{				//io cs
			writel(1, gscs->regs + GSC_SPI_CS);
			for(i=0;i<gscs->cur_chip->pin_cnt;i++)
				gpio_set_value(gscs->cur_chip->pin_cs[i],((gscs->cur_chip->cs_value>>(i+1))&0x1));
	}

	/* get first transfer */
	gscs->cur_transfer = list_entry(gscs->cur_msg->transfers.next, struct spi_transfer, transfer_list);
	if (!gscs->cur_transfer) {
		DBG("!!!!gsc3280_spi_pump_transfers: current no transfer!\n");
		return;
	}
	tasklet_schedule(&gscs->pump_transfers);
	gscs->busy = 1;
	spin_unlock_irqrestore(&gscs->slock, flags);
	return;
}

/* spi driver call this function transfer data */
static int gsc3280_spi_transfer(struct spi_device *spi, struct spi_message *msg)
{
	unsigned long flags = 0;
	struct gsc3280_spi *gscs = spi_master_get_devdata(spi->master);

	spin_lock_irqsave(&gscs->slock, flags);
	if (gscs->queue_state == GSC_SPI_QUEUE_STOP) {
		spin_unlock_irqrestore(&gscs->slock, flags);
		return -ESHUTDOWN;
	}
	msg->actual_length = 0;
	msg->status = -EINPROGRESS;
	msg->state = START_STATE;

	list_add_tail(&msg->queue, &gscs->queue);

	if (gscs->queue_state == GSC_SPI_QUEUE_RUN && !gscs->busy) {
		DBG("####gsc3280 spi transfer start####\n");

                if (gscs->cur_transfer || gscs->cur_msg) {
                        queue_work(gscs->workqueue,
                                        &gscs->pump_messages);
			printk(KERN_CRIT "queue message\n");
		}
                else {
                        /* If no other data transaction in air, just go */
                        spin_unlock_irqrestore(&gscs->slock, flags);
                        gsc3280_spi_pump_messages(&gscs->pump_messages);
//			printk(KERN_CRIT "transfer ok.\n");
                        return 0;
                }
        }
	spin_unlock_irqrestore(&gscs->slock, flags);
	DBG("####gsc3280 spi transfer success####\n");
	return 0;
}

/* This may be called twice for each spi dev */
static int gsc3280_spi_setup(struct spi_device *spi)
{
	int i,clk_div,ret = 0;
	struct chip_data *chip = NULL;
	struct gsc3280_spi_info *chip_info = NULL;
	struct gsc3280_spi *gscs = spi_master_get_devdata(spi->master);

	DBG("######gsc3280 spi bus setup start######\n");
	chip = spi_get_ctldata(spi);		/* Only alloc on first setup */
	if (!chip) {
		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
		if (!chip) {
			DBG("!!!!kzalloc error!\n");
			ret = -ENOMEM;
			goto exit;
		}
	}
	chip_info = spi->controller_data;
	/* chip_info doesn't always exist */
	if (chip_info) {
#ifdef CONFIG_GSC3280_SPI_DMA
		chip->enable_dma = chip_info->enable_dma;
#endif
		chip->poll_mode = chip_info->poll_mode;
		chip->cs_type = chip_info->cs_type;
		chip->cs_value = chip_info->cs_value;
		chip->bits_per_word = chip_info->bits_per_word;
		chip->lsb_flg = chip_info->lsb_flg;
		chip->pin_cnt = chip_info->pin_cnt;
		//init cancel cs
		if (chip->cs_type == 0)		//chip cs
				writel(1, gscs->regs + GSC_SPI_CS);
		else{				//io cs
			for(i=0;i<chip->pin_cnt;i++){
				chip->pin_cs[i]=chip_info->pin_cs[i];
				if(gpio_request(chip->pin_cs[i], spi->modalias)==0)
					gpio_direction_output(chip->pin_cs[i],~((chip->cs_value>>(i+1))&0x1));
			}
		}
	}
	if (spi->bits_per_word == 8) {
		chip->n_bytes = 1;
#ifdef CONFIG_GSC3280_SPI_DMA
		chip->dma_width = 1;
#endif
	} else if (spi->bits_per_word == 16) {
		chip->n_bytes = 2;
#ifdef CONFIG_GSC3280_SPI_DMA
		chip->dma_width = 2;
#endif
	} else {
		DBG("!!!!spi->bits_per_word = %d error!\n", spi->bits_per_word);
		ret = -EINVAL;
		goto exit;
	}

	if(spi->max_speed_hz > gscs->max_freq/2)
		chip->speed_hz = gscs->max_freq/2;
	else
		chip->speed_hz = spi->max_speed_hz;

	clk_div = gscs->max_freq / chip->speed_hz;
//	if((gscs->max_freq%chip->speed_hz)>0)
//		clk_div +=1;
	if(clk_div%2)
		clk_div = clk_div/2;
	else
		clk_div = (clk_div/2) -1;
	
	writel(clk_div , gscs->regs + GSC_SPI_SEABAUR);
	printk(KERN_INFO "SPI: max freq  = %dHz\n", gscs->max_freq);
    printk(KERN_INFO "SPI: max speed = %dHz\n", spi->max_speed_hz);
	printk(KERN_INFO "SPI: rel speed = %dHz\n", gscs->max_freq/((clk_div+1)*2));

	chip->cr = (chip->lsb_flg << GSC_SPI_CTL_LSB) | (spi->mode  << GSC_SPI_CTL_MOD)
				| ((chip->bits_per_word - 1) << GSC_SPI_CTL_DSS);
	spi_set_ctldata(spi, chip);

exit:
	if (ret != 0)
		DBG("!!!!gsc3280 spi bus setup error!\n");
	else
		DBG("######gsc3280 spi bus setup success######\n");
	return ret;
}

static void gsc3280_spi_cleanup(struct spi_device *spi)
{
	struct chip_data *chip = spi_get_ctldata(spi);
	
	kfree(chip);
}

static int __devinit gsc3280_init_queue(struct gsc3280_spi *gscs)
{
	INIT_LIST_HEAD(&gscs->queue);
	spin_lock_init(&gscs->slock);
	gscs->queue_state = GSC_SPI_QUEUE_STOP;
	gscs->busy = 0;
	tasklet_init(&gscs->pump_transfers, gsc3280_spi_pump_transfers, (unsigned long)gscs);
	INIT_WORK(&gscs->pump_messages, gsc3280_spi_pump_messages);
	gscs->workqueue = create_singlethread_workqueue(dev_name(gscs->master->dev.parent));
	if (gscs->workqueue == NULL) {
		return -EBUSY;
	}
	return 0;
}

static int gsc3280_start_queue(struct gsc3280_spi *gscs)
{
	unsigned long flags = 0;

	spin_lock_irqsave(&gscs->slock, flags);
	if ((gscs->queue_state == GSC_SPI_QUEUE_RUN) || gscs->busy) {
		spin_unlock_irqrestore(&gscs->slock, flags);
		return -EBUSY;
	}
	gscs->queue_state = GSC_SPI_QUEUE_RUN;
	gscs->cur_msg = NULL;
	gscs->cur_transfer = NULL;
	gscs->cur_chip = NULL;
	gscs->prev_chip = NULL;
	spin_unlock_irqrestore(&gscs->slock, flags);
	queue_work(gscs->workqueue, &gscs->pump_messages);
	return 0;
}

static int gsc3280_spi_stop_queue(struct gsc3280_spi *gscs)
{
	int ret = 0;
	unsigned long flags;
	unsigned limit = 50;
	
	spin_lock_irqsave(&gscs->slock, flags);
	while ((!list_empty(&gscs->queue) || gscs->busy) && limit--) {
		spin_unlock_irqrestore(&gscs->slock, flags);
		msleep(10);
		spin_lock_irqsave(&gscs->slock, flags);
	}
	if (!list_empty(&gscs->queue) || gscs->busy)
		ret = -EBUSY;
	else
		gscs->queue_state = GSC_SPI_QUEUE_STOP;
	spin_unlock_irqrestore(&gscs->slock, flags);
	return ret;
}

static int gsc3280_spi_destroy_queue(struct gsc3280_spi *gscs)
{
	int ret = 0;

	ret = gsc3280_spi_stop_queue(gscs);
	if (ret != 0)
		return ret;
	destroy_workqueue(gscs->workqueue);
	return ret;
}

/* Restart the controller, disable all interrupts, clean fifo */
static void gsc3280_spi_hw_init(struct gsc3280_spi *gscs)
{
	gsc3280_enable_spi(gscs, GSC_SPI_DISABLE);
	gsc3280_spi_mask_intr(gscs, GSC_SPI_SR_MASK);
	if (!gscs->fifo_len) {
		if(gscs->irq == 14) //spi0
			gscs->fifo_len = 0x8;
		else				//spi1
			gscs->fifo_len = 0x10;
	}
	writew(0x00, gscs->regs + GSC_SPI_TXFTLR);
	writew(0x00, gscs->regs + GSC_SPI_RXFTLR);
	gsc3280_spi_clr_fifo(gscs);
	gsc3280_enable_spi(gscs, GSC_SPI_ENABLE);
}

static int __init gsc3280_spi_probe(struct platform_device *pdev)
{
	int ret = 0;
	struct gsc3280_spi *gscs;
	struct spi_master *master;
	struct resource *mem, *ioarea;

	/*When used high speed SPI, then must  reconfig the SPI clock */
	/*SPI0 ReInit*/
    __raw_writel(0x1,(__iomem void *)GSC3280_REGADDR_SYSCTL_CLKDIV_SPI0);
	/*SPI1 ReInit*/
    __raw_writel(0x1,(__iomem void *)GSC3280_REGADDR_SYSCTL_CLKDIV_SPI1);

	DBG("############\n");
	DBG("gsc3280 spi probe start\n");
	master = spi_alloc_master(&pdev->dev, sizeof(struct gsc3280_spi));
	if (!master) {
		ret = -ENOMEM;
		DBG("!!!!spi_alloc_master error\n");
		goto exit;
	}
	gscs = spi_master_get_devdata(master);
	memset(gscs, 0, sizeof(struct gsc3280_spi));
	gscs->master = spi_master_get(master);
	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);                           
	if (!mem) {
		DBG("!!!!no mem resource!\n");
		ret = -EINVAL;
		goto err_kfree;
	}
	ioarea = request_mem_region(mem->start, resource_size(mem), pdev->name);                                                    
	if (!ioarea) {
		DBG("!!!!SPI region already claimed!\n");
		ret = -EBUSY;
		goto err_kfree;
	}
	gscs->regs = ioremap_nocache(mem->start, resource_size(mem));                    
	if (!gscs->regs) {
		DBG("!!!!SPI ioremap error!\n");
		ret = -ENOMEM;
		goto err_release_reg;
	}
	DBG("gscs->regs = 0x%p\n", gscs->regs);
	gscs->irq = platform_get_irq(pdev, 0); 
	if (gscs->irq < 0) {
		DBG("!!!!no irq resource!\n");
		ret = gscs->irq;
		goto err_unmap;
	}
	ret = request_irq(gscs->irq, gsc3280_spi_irq, IRQF_DISABLED, dev_name(&pdev->dev), gscs);
	if (ret < 0) {
		DBG("!!!!can not get IRQ!\n");
		goto err_irq;
	}
	gscs->clk = clk_get(NULL, pdev->dev.platform_data);
	if (IS_ERR(gscs->clk)) {
		DBG("!!!!failed to find spi1 clock source!\n");
		ret = PTR_ERR(gscs->clk);
		goto err_irq;
	}
	gscs->max_freq = clk_get_rate(gscs->clk);
	clk_enable(gscs->clk);
	gscs->bus_num = pdev->id;
	gscs->num_cs = 4;
	gscs->prev_chip = NULL;
	
#ifdef CONFIG_GSC3280_SPI_DMA
//	gscs->dma_priv = pdev->dev.platform_data = &spi_platform_data;
	gscs->dma_priv = pdev->dev.platform_data;
	pdata = pdev->dev.platform_data;

	if (!gscs->dma_priv)
		goto err_clk;
	gscs->dma_ops = &gscs_dma_ops;
	gscs->dma_inited = 0;
	gscs->dma_addr = (dma_addr_t)(gscs->regs + 0x24) & 0x1fffffff;
#endif
	platform_set_drvdata(pdev, master);
	master->mode_bits = SPI_CPOL | SPI_CPHA |SPI_CS_HIGH;
	master->bus_num = gscs->bus_num;
	master->num_chipselect = gscs->num_cs;
	master->cleanup = gsc3280_spi_cleanup;
	master->setup = gsc3280_spi_setup;
	master->transfer = gsc3280_spi_transfer;
	gsc3280_spi_hw_init(gscs);
#ifdef CONFIG_GSC3280_SPI_DMA
	if (gscs->dma_ops && gscs->dma_ops->dma_init) {
		ret = gscs->dma_ops->dma_init(gscs);
		if (ret) {
			dev_warn(&master->dev, "DMA init failed\n");
			gscs->dma_inited = 0;
		}
	}
#endif
	ret = gsc3280_init_queue(gscs);
	if (ret != 0) {
		DBG("!!!!problem initializing queue!\n");
		goto err_diable_hw;
	}
	ret = gsc3280_start_queue(gscs);
	if (ret != 0) {
		DBG("!!!!problem starting queue!\n");
		goto err_queue_alloc;
	}
	ret = spi_register_master(master);
	if (ret != 0) {
		DBG("!!!!register spi master error!\n");
		goto err_queue_alloc;
	}

	DBG("gsc3280 spi probe success\n");
	DBG("############\n");
	return 0;

//err_free_master:
	//spi_master_put(master);
err_queue_alloc:
	gsc3280_spi_destroy_queue(gscs);
#ifdef CONFIG_GSC3280_SPI_DMA
	if (gscs->dma_ops && gscs->dma_ops->dma_exit)
		gscs->dma_ops->dma_exit(gscs);
#endif
err_diable_hw:
	gsc3280_enable_spi(gscs, GSC_SPI_DISABLE);
err_clk:
	clk_disable(gscs->clk);
	clk_put(gscs->clk);
err_irq:
	free_irq(gscs->irq, gscs);
err_unmap:
	iounmap(gscs->regs);
err_release_reg:
	release_mem_region(mem->start, resource_size(mem));
err_kfree:
	kfree(gscs);
	kfree(master);
exit:
	printk(KERN_ERR "!!!!!!gsc3280 probe error!!!!!!\n");
	return ret;
}

void __exit gsc3280_spi_remove(struct platform_device *pdev)
{
	int ret = 0;
	struct spi_master *master = platform_get_drvdata(pdev);
	struct gsc3280_spi *gscs = spi_master_get_devdata(master);

	if (!gscs)
		return;
	ret = gsc3280_spi_destroy_queue(gscs);
	if (ret != 0)
		dev_err(&gscs->master->dev, "gsc3280_spi_remove: workqueue will not "
			"complete, message memory not freed\n");

#ifdef CONFIG_GSC3280_SPI_DMA
	if (gscs->dma_ops && gscs->dma_ops->dma_exit)
		gscs->dma_ops->dma_exit(gscs);
#endif

	gsc3280_enable_spi(gscs, GSC_SPI_DISABLE);
	free_irq(gscs->irq, gscs);
	iounmap(gscs->regs);
	clk_disable(gscs->clk);
	clk_put(gscs->clk);
	gscs->clk = NULL;
	spi_unregister_master(gscs->master);
}

static int gsc3280_spi_suspend(struct platform_device *pdev, pm_message_t mesg)
{
	int ret = 0;
	struct spi_master *master = platform_get_drvdata(pdev);
	struct gsc3280_spi *gscs = spi_master_get_devdata(master);

	ret = gsc3280_spi_stop_queue(gscs);
	if (ret != 0)
		return ret;
	gsc3280_enable_spi(gscs, GSC_SPI_DISABLE);
	return ret;
}

static int gsc3280_spi_resume(struct platform_device *pdev)
{
	int ret = 0;
	struct spi_master *master = platform_get_drvdata(pdev);
	struct gsc3280_spi *gscs = spi_master_get_devdata(master);

	gsc3280_spi_hw_init(gscs);
	ret = gsc3280_start_queue(gscs);
	if (ret != 0)
		dev_err(&gscs->master->dev, "fail to start queue (%d)\n", ret);
	return ret;
}

static struct platform_driver gsc3280_spi_driver = {
	.driver	= {
		.name	= "gsc3280-spi",
		.owner	= THIS_MODULE,
	},
	.suspend = gsc3280_spi_suspend,
	.resume	= gsc3280_spi_resume,
	.remove	= __exit_p(gsc3280_spi_remove),
};

static int __init gsc3280_spi_init(void)
{
	platform_driver_probe(&gsc3280_spi_driver, gsc3280_spi_probe);
	return 0;
}
static void __exit gsc3280_spi_exit(void)
{
	platform_driver_unregister(&gsc3280_spi_driver);
}
module_init(gsc3280_spi_init);
module_exit(gsc3280_spi_exit);

MODULE_DESCRIPTION("BLX GSC3280 SoC SPI Controller driver");
MODULE_AUTHOR("Davied<apple_guet@126.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:gsc3280-spi");