1 files changed, 78 insertions, 33 deletions

diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c
index 31620fae77be..8ed38f1d6c18 100644
--- a/drivers/spi/dw_spi.c
+++ b/drivers/spi/dw_spi.c
@@ -152,6 +152,7 @@ static void mrst_spi_debugfs_remove(struct dw_spi *dws)
 #else
 static inline int mrst_spi_debugfs_init(struct dw_spi *dws)
 {
+        return 0;
 }
 
 static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
@@ -161,14 +162,14 @@ static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
 
 static void wait_till_not_busy(struct dw_spi *dws)
 {
-        unsigned long end = jiffies + usecs_to_jiffies(1000);
+        unsigned long end = jiffies + 1 + usecs_to_jiffies(1000);
 
         while (time_before(jiffies, end)) {
                 if (!(dw_readw(dws, sr) & SR_BUSY))
                         return;
         }
         dev_err(&dws->master->dev,
-                "DW SPI: Stutus keeps busy for 1000us after a read/write!\n");
+                "DW SPI: Status keeps busy for 1000us after a read/write!\n");
 }
 
 static void flush(struct dw_spi *dws)
@@ -358,6 +359,8 @@ static void transfer_complete(struct dw_spi *dws)
 static irqreturn_t interrupt_transfer(struct dw_spi *dws)
 {
         u16 irq_status, irq_mask = 0x3f;
+        u32 int_level = dws->fifo_len / 2;
+        u32 left;
 
         irq_status = dw_readw(dws, isr) & irq_mask;
         /* Error handling */
@@ -369,22 +372,23 @@ static irqreturn_t interrupt_transfer(struct dw_spi *dws)
                 return IRQ_HANDLED;
         }
 
-        /* INT comes from tx */
-        if (dws->tx && (irq_status & SPI_INT_TXEI)) {
-                while (dws->tx < dws->tx_end)
+        if (irq_status & SPI_INT_TXEI) {
+                spi_mask_intr(dws, SPI_INT_TXEI);
+
+                left = (dws->tx_end - dws->tx) / dws->n_bytes;
+                left = (left > int_level) ? int_level : left;
+
+                while (left--)
                         dws->write(dws);
+                dws->read(dws);
 
-                if (dws->tx == dws->tx_end) {
-                        spi_mask_intr(dws, SPI_INT_TXEI);
+                /* Re-enable the IRQ if there is still data left to tx */
+                if (dws->tx_end > dws->tx)
+                        spi_umask_intr(dws, SPI_INT_TXEI);
+                else
                         transfer_complete(dws);
-                }
         }
 
-        /* INT comes from rx */
-        if (dws->rx && (irq_status & SPI_INT_RXFI)) {
-                if (dws->read(dws))
-                        transfer_complete(dws);
-        }
         return IRQ_HANDLED;
 }
 
@@ -404,12 +408,9 @@ static irqreturn_t dw_spi_irq(int irq, void *dev_id)
 /* Must be called inside pump_transfers() */
 static void poll_transfer(struct dw_spi *dws)
 {
-        if (dws->tx) {
-                while (dws->write(dws))
-                        dws->read(dws);
-        }
+        while (dws->write(dws))
+                dws->read(dws);
 
-        dws->read(dws);
         transfer_complete(dws);
 }
 
@@ -428,6 +429,7 @@ static void pump_transfers(unsigned long data)
         u8 bits = 0;
         u8 imask = 0;
         u8 cs_change = 0;
+        u16 txint_level = 0;
         u16 clk_div = 0;
         u32 speed = 0;
         u32 cr0 = 0;
@@ -438,6 +440,9 @@ static void pump_transfers(unsigned long data)
         chip = dws->cur_chip;
         spi = message->spi;
 
+        if (unlikely(!chip->clk_div))
+                chip->clk_div = dws->max_freq / chip->speed_hz;
+
         if (message->state == ERROR_STATE) {
                 message->status = -EIO;
                 goto early_exit;
@@ -492,7 +497,7 @@ static void pump_transfers(unsigned long data)
 
                         /* clk_div doesn't support odd number */
                         clk_div = dws->max_freq / speed;
-                        clk_div = (clk_div >> 1) << 1;
+                        clk_div = (clk_div + 1) & 0xfffe;
 
                         chip->speed_hz = speed;
                         chip->clk_div = clk_div;
@@ -532,14 +537,35 @@ static void pump_transfers(unsigned long data)
         }
         message->state = RUNNING_STATE;
 
+        /*
+         * Adjust transfer mode if necessary. Requires platform dependent
+         * chipselect mechanism.
+         */
+        if (dws->cs_control) {
+                if (dws->rx && dws->tx)
+                        chip->tmode = 0x00;
+                else if (dws->rx)
+                        chip->tmode = 0x02;
+                else
+                        chip->tmode = 0x01;
+
+                cr0 &= ~(0x3 << SPI_MODE_OFFSET);
+                cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
+        }
+
         /* Check if current transfer is a DMA transaction */
         dws->dma_mapped = map_dma_buffers(dws);
 
+        /*
+         * Interrupt mode
+         * we only need set the TXEI IRQ, as TX/RX always happen syncronizely
+         */
         if (!dws->dma_mapped && !chip->poll_mode) {
-                if (dws->rx)
-                        imask |= SPI_INT_RXFI;
-                if (dws->tx)
-                        imask |= SPI_INT_TXEI;
+                int templen = dws->len / dws->n_bytes;
+                txint_level = dws->fifo_len / 2;
+                txint_level = (templen > txint_level) ? txint_level : templen;
+
+                imask |= SPI_INT_TXEI;
                 dws->transfer_handler = interrupt_transfer;
         }
 
@@ -549,21 +575,23 @@ static void pump_transfers(unsigned long data)
          *      2. clk_div is changed
          *      3. control value changes
          */
-        if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div) {
+        if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div || imask) {
                 spi_enable_chip(dws, 0);
 
                 if (dw_readw(dws, ctrl0) != cr0)
                         dw_writew(dws, ctrl0, cr0);
 
+                spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
+                spi_chip_sel(dws, spi->chip_select);
+
                 /* Set the interrupt mask, for poll mode just diable all int */
                 spi_mask_intr(dws, 0xff);
-                if (!chip->poll_mode)
+                if (imask)
                         spi_umask_intr(dws, imask);
+                if (txint_level)
+                        dw_writew(dws, txfltr, txint_level);
 
-                spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
-                spi_chip_sel(dws, spi->chip_select);
                 spi_enable_chip(dws, 1);
-
                 if (cs_change)
                         dws->prev_chip = chip;
         }
@@ -712,11 +740,11 @@ static int dw_spi_setup(struct spi_device *spi)
         }
         chip->bits_per_word = spi->bits_per_word;
 
+        if (!spi->max_speed_hz) {
+                dev_err(&spi->dev, "No max speed HZ parameter\n");
+                return -EINVAL;
+        }
         chip->speed_hz = spi->max_speed_hz;
-        if (chip->speed_hz)
-                chip->clk_div = 25000000 / chip->speed_hz;
-        else
-                chip->clk_div = 8;      /* default value */
 
         chip->tmode = 0; /* Tx & Rx */
         /* Default SPI mode is SCPOL = 0, SCPH = 0 */
@@ -735,7 +763,7 @@ static void dw_spi_cleanup(struct spi_device *spi)
         kfree(chip);
 }
 
-static int __init init_queue(struct dw_spi *dws)
+static int __devinit init_queue(struct dw_spi *dws)
 {
         INIT_LIST_HEAD(&dws->queue);
         spin_lock_init(&dws->lock);
@@ -817,6 +845,22 @@ static void spi_hw_init(struct dw_spi *dws)
         spi_mask_intr(dws, 0xff);
         spi_enable_chip(dws, 1);
         flush(dws);
+
+        /*
+         * Try to detect the FIFO depth if not set by interface driver,
+         * the depth could be from 2 to 256 from HW spec
+         */
+        if (!dws->fifo_len) {
+                u32 fifo;
+                for (fifo = 2; fifo <= 257; fifo++) {
+                        dw_writew(dws, txfltr, fifo);
+                        if (fifo != dw_readw(dws, txfltr))
+                                break;
+                }
+
+                dws->fifo_len = (fifo == 257) ? 0 : fifo;
+                dw_writew(dws, txfltr, 0);
+        }
 }
 
 int __devinit dw_spi_add_host(struct dw_spi *dws)
@@ -913,6 +957,7 @@ void __devexit dw_spi_remove_host(struct dw_spi *dws)
         /* Disconnect from the SPI framework */
         spi_unregister_master(dws->master);
 }
+EXPORT_SYMBOL(dw_spi_remove_host);
 
 int dw_spi_suspend_host(struct dw_spi *dws)
 {