This patch corrects the behavior of the BLOCK
transactions.  During block transactions, the controller
must be read/written to in block size transactions.

Signed-off-by: Andy Gross <andy.gr...@linaro.org>
Signed-off-by: Varadarajan Narayanan <var...@codeaurora.org>
---
 drivers/spi/spi-qup.c | 151 +++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 119 insertions(+), 32 deletions(-)

diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
index 0f6a4c7..872de28 100644
--- a/drivers/spi/spi-qup.c
+++ b/drivers/spi/spi-qup.c
@@ -82,6 +82,8 @@
 #define QUP_IO_M_MODE_BAM              3
 
 /* QUP_OPERATIONAL fields */
+#define QUP_OP_IN_BLOCK_READ_REQ       BIT(13)
+#define QUP_OP_OUT_BLOCK_WRITE_REQ     BIT(12)
 #define QUP_OP_MAX_INPUT_DONE_FLAG     BIT(11)
 #define QUP_OP_MAX_OUTPUT_DONE_FLAG    BIT(10)
 #define QUP_OP_IN_SERVICE_FLAG         BIT(9)
@@ -156,6 +158,13 @@ struct spi_qup {
        struct dma_slave_config tx_conf;
 };
 
+static inline bool spi_qup_is_flag_set(struct spi_qup *controller, u32 flag)
+{
+       u32 opflag = readl_relaxed(controller->base + QUP_OPERATIONAL);
+
+       return (opflag & flag) != 0;
+}
+
 static inline bool spi_qup_is_dma_xfer(int mode)
 {
        if (mode == QUP_IO_M_MODE_DMOV || mode == QUP_IO_M_MODE_BAM)
@@ -216,29 +225,26 @@ static int spi_qup_set_state(struct spi_qup *controller, 
u32 state)
        return 0;
 }
 
-static void spi_qup_fifo_read(struct spi_qup *controller,
-                           struct spi_transfer *xfer)
+static void spi_qup_read_from_fifo(struct spi_qup *controller,
+       struct spi_transfer *xfer, u32 num_words)
 {
        u8 *rx_buf = xfer->rx_buf;
-       u32 word, state;
-       int idx, shift, w_size;
+       int i, shift, num_bytes;
+       u32 word;
 
-       w_size = controller->w_size;
-
-       while (controller->rx_bytes < xfer->len) {
-
-               state = readl_relaxed(controller->base + QUP_OPERATIONAL);
-               if (0 == (state & QUP_OP_IN_FIFO_NOT_EMPTY))
-                       break;
+       for (; num_words; num_words--) {
 
                word = readl_relaxed(controller->base + QUP_INPUT_FIFO);
 
+               num_bytes = min_t(int, xfer->len - controller->rx_bytes,
+                                       controller->w_size);
+
                if (!rx_buf) {
-                       controller->rx_bytes += w_size;
+                       controller->rx_bytes += num_bytes;
                        continue;
                }
 
-               for (idx = 0; idx < w_size; idx++, controller->rx_bytes++) {
+               for (i = 0; i < num_bytes; i++, controller->rx_bytes++) {
                        /*
                         * The data format depends on bytes per SPI word:
                         *  4 bytes: 0x12345678
@@ -246,38 +252,80 @@ static void spi_qup_fifo_read(struct spi_qup *controller,
                         *  1 byte : 0x00000012
                         */
                        shift = BITS_PER_BYTE;
-                       shift *= (w_size - idx - 1);
+                       shift *= (controller->w_size - i - 1);
                        rx_buf[controller->rx_bytes] = word >> shift;
                }
        }
 }
 
-static void spi_qup_fifo_write(struct spi_qup *controller,
+static void spi_qup_read(struct spi_qup *controller,
                            struct spi_transfer *xfer)
 {
-       const u8 *tx_buf = xfer->tx_buf;
-       u32 word, state, data;
-       int idx, w_size;
+       u32 remainder, words_per_block, num_words;
+       bool is_block_mode = controller->mode == QUP_IO_M_MODE_BLOCK;
+
+       remainder = DIV_ROUND_UP(xfer->len - controller->rx_bytes,
+                                controller->w_size);
+       words_per_block = controller->in_blk_sz >> 2;
+
+       do {
+               /* ACK by clearing service flag */
+               writel_relaxed(QUP_OP_IN_SERVICE_FLAG,
+                              controller->base + QUP_OPERATIONAL);
+
+               if (is_block_mode) {
+                       num_words = (remainder > words_per_block) ?
+                                       words_per_block : remainder;
+               } else {
+                       if (!spi_qup_is_flag_set(controller,
+                                                QUP_OP_IN_FIFO_NOT_EMPTY))
+                               break;
 
-       w_size = controller->w_size;
+                       num_words = 1;
+               }
 
-       while (controller->tx_bytes < xfer->len) {
+               /* read up to the maximum transfer size available */
+               spi_qup_read_from_fifo(controller, xfer, num_words);
 
-               state = readl_relaxed(controller->base + QUP_OPERATIONAL);
-               if (state & QUP_OP_OUT_FIFO_FULL)
+               remainder -= num_words;
+
+               /* if block mode, check to see if next block is available */
+               if (is_block_mode && !spi_qup_is_flag_set(controller,
+                                       QUP_OP_IN_BLOCK_READ_REQ))
                        break;
 
+       } while (remainder);
+
+       /*
+        * Due to extra stickiness of the QUP_OP_IN_SERVICE_FLAG during block
+        * mode reads, it has to be cleared again at the very end
+        */
+       if (is_block_mode && spi_qup_is_flag_set(controller,
+                               QUP_OP_MAX_INPUT_DONE_FLAG))
+               writel_relaxed(QUP_OP_IN_SERVICE_FLAG,
+                              controller->base + QUP_OPERATIONAL);
+
+}
+
+static void spi_qup_write_to_fifo(struct spi_qup *controller,
+       struct spi_transfer *xfer, u32 num_words)
+{
+       const u8 *tx_buf = xfer->tx_buf;
+       int i, num_bytes;
+       u32 word, data;
+
+       for (; num_words; num_words--) {
                word = 0;
-               for (idx = 0; idx < w_size; idx++, controller->tx_bytes++) {
 
-                       if (!tx_buf) {
-                               controller->tx_bytes += w_size;
-                               break;
+               num_bytes = min_t(int, xfer->len - controller->tx_bytes,
+                                   controller->w_size);
+               if (tx_buf)
+                       for (i = 0; i < num_bytes; i++) {
+                               data = tx_buf[controller->tx_bytes + i];
+                               word |= data << (BITS_PER_BYTE * (3 - i));
                        }
 
-                       data = tx_buf[controller->tx_bytes];
-                       word |= data << (BITS_PER_BYTE * (3 - idx));
-               }
+               controller->tx_bytes += num_bytes;
 
                writel_relaxed(word, controller->base + QUP_OUTPUT_FIFO);
        }
@@ -288,6 +336,44 @@ static void spi_qup_dma_done(void *data)
        complete(data);
 }
 
+static void spi_qup_write(struct spi_qup *controller,
+                           struct spi_transfer *xfer)
+{
+       bool is_block_mode = controller->mode == QUP_IO_M_MODE_BLOCK;
+       u32 remainder, words_per_block, num_words;
+
+       remainder = DIV_ROUND_UP(xfer->len - controller->tx_bytes,
+                                controller->w_size);
+       words_per_block = controller->out_blk_sz >> 2;
+
+       do {
+               /* ACK by clearing service flag */
+               writel_relaxed(QUP_OP_OUT_SERVICE_FLAG,
+                              controller->base + QUP_OPERATIONAL);
+
+               if (is_block_mode) {
+                       num_words = (remainder > words_per_block) ?
+                               words_per_block : remainder;
+               } else {
+                       if (spi_qup_is_flag_set(controller,
+                                               QUP_OP_OUT_FIFO_FULL))
+                               break;
+
+                       num_words = 1;
+               }
+
+               spi_qup_write_to_fifo(controller, xfer, num_words);
+
+               remainder -= num_words;
+
+               /* if block mode, check to see if next block is available */
+               if (is_block_mode && !spi_qup_is_flag_set(controller,
+                                       QUP_OP_OUT_BLOCK_WRITE_REQ))
+                       break;
+
+       } while (remainder);
+}
+
 static int spi_qup_prep_sg(struct spi_master *master, struct spi_transfer 
*xfer,
                           enum dma_transfer_direction dir,
                           dma_async_tx_callback callback, void *data)
@@ -390,7 +476,8 @@ static int spi_qup_do_pio(struct spi_master *master, struct 
spi_transfer *xfer,
                return ret;
        }
 
-       spi_qup_fifo_write(qup, xfer);
+       if (qup->mode == QUP_IO_M_MODE_FIFO)
+               spi_qup_write(qup, xfer);
 
        ret = spi_qup_set_state(qup, QUP_STATE_RUN);
        if (ret) {
@@ -455,10 +542,10 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
 
        if (!spi_qup_is_dma_xfer(controller->mode)) {
                if (opflags & QUP_OP_IN_SERVICE_FLAG)
-                       spi_qup_fifo_read(controller, xfer);
+                       spi_qup_read(controller, xfer);
 
                if (opflags & QUP_OP_OUT_SERVICE_FLAG)
-                       spi_qup_fifo_write(controller, xfer);
+                       spi_qup_write(controller, xfer);
        }
 
        spin_lock_irqsave(&controller->lock, flags);
-- 
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