target/linux/ipq806x/patches-4.9/0006-spi-qup-Fix-block-mode-to-work-correctly.patch

   1 From b56c1e35cc550fd014fa601ca56b964d88fd44a9 Mon Sep 17 00:00:00 2001
   2 From: Andy Gross <andy.gross@linaro.org>
   3 Date: Sun, 31 Jan 2016 21:28:13 -0600
   4 Subject: [PATCH 06/69] spi: qup: Fix block mode to work correctly
   5
   6 This patch corrects the behavior of the BLOCK transactions.  During block
   7 transactions, the controller must be read/written to in block size transactions.
   8
   9 Signed-off-by: Andy Gross <andy.gross@linaro.org>
  10 ---
  11  drivers/spi/spi-qup.c | 182 +++++++++++++++++++++++++++++++++++++++-----------
  12  1 file changed, 142 insertions(+), 40 deletions(-)
  13
  14 --- a/drivers/spi/spi-qup.c
  15 +++ b/drivers/spi/spi-qup.c
  16 @@ -82,6 +82,8 @@
  17  #define QUP_IO_M_MODE_BAM              3
  18
  19  /* QUP_OPERATIONAL fields */
  20 +#define QUP_OP_IN_BLOCK_READ_REQ       BIT(13)
  21 +#define QUP_OP_OUT_BLOCK_WRITE_REQ     BIT(12)
  22  #define QUP_OP_MAX_INPUT_DONE_FLAG     BIT(11)
  23  #define QUP_OP_MAX_OUTPUT_DONE_FLAG    BIT(10)
  24  #define QUP_OP_IN_SERVICE_FLAG         BIT(9)
  25 @@ -155,6 +157,12 @@ struct spi_qup {
  26         struct dma_slave_config tx_conf;
  27  };
  28
  29 +static inline bool spi_qup_is_flag_set(struct spi_qup *controller, u32 flag)
  30 +{
  31 +       u32 opflag = readl_relaxed(controller->base + QUP_OPERATIONAL);
  32 +
  33 +       return opflag & flag;
  34 +}
  35
  36  static inline bool spi_qup_is_dma_xfer(int mode)
  37  {
  38 @@ -216,29 +224,26 @@ static int spi_qup_set_state(struct spi_
  39         return 0;
  40  }
  41
  42 -static void spi_qup_fifo_read(struct spi_qup *controller,
  43 -                           struct spi_transfer *xfer)
  44 +static void spi_qup_read_from_fifo(struct spi_qup *controller,
  45 +       struct spi_transfer *xfer, u32 num_words)
  46  {
  47         u8 *rx_buf = xfer->rx_buf;
  48 -       u32 word, state;
  49 -       int idx, shift, w_size;
  50 -
  51 -       w_size = controller->w_size;
  52 +       int i, shift, num_bytes;
  53 +       u32 word;
  54
  55 -       while (controller->rx_bytes < xfer->len) {
  56 -
  57 -               state = readl_relaxed(controller->base + QUP_OPERATIONAL);
  58 -               if (0 == (state & QUP_OP_IN_FIFO_NOT_EMPTY))
  59 -                       break;
  60 +       for (; num_words; num_words--) {
  61
  62                 word = readl_relaxed(controller->base + QUP_INPUT_FIFO);
  63
  64 +               num_bytes = min_t(int, xfer->len - controller->rx_bytes,
  65 +                                       controller->w_size);
  66 +
  67                 if (!rx_buf) {
  68 -                       controller->rx_bytes += w_size;
  69 +                       controller->rx_bytes += num_bytes;
  70                         continue;
  71                 }
  72
  73 -               for (idx = 0; idx < w_size; idx++, controller->rx_bytes++) {
  74 +               for (i = 0; i < num_bytes; i++, controller->rx_bytes++) {
  75                         /*
  76                          * The data format depends on bytes per SPI word:
  77                          *  4 bytes: 0x12345678
  78 @@ -246,38 +251,80 @@ static void spi_qup_fifo_read(struct spi
  79                          *  1 byte : 0x00000012
  80                          */
  81                         shift = BITS_PER_BYTE;
  82 -                       shift *= (w_size - idx - 1);
  83 +                       shift *= (controller->w_size - i - 1);
  84                         rx_buf[controller->rx_bytes] = word >> shift;
  85                 }
  86         }
  87  }
  88
  89 -static void spi_qup_fifo_write(struct spi_qup *controller,
  90 +static void spi_qup_read(struct spi_qup *controller,
  91                             struct spi_transfer *xfer)
  92  {
  93 -       const u8 *tx_buf = xfer->tx_buf;
  94 -       u32 word, state, data;
  95 -       int idx, w_size;
  96 +       u32 remainder, words_per_block, num_words;
  97 +       bool is_block_mode = controller->mode == QUP_IO_M_MODE_BLOCK;
  98 +
  99 +       remainder = DIV_ROUND_UP(xfer->len - controller->rx_bytes,
 100 +                                controller->w_size);
 101 +       words_per_block = controller->in_blk_sz >> 2;
 102 +
 103 +       do {
 104 +               /* ACK by clearing service flag */
 105 +               writel_relaxed(QUP_OP_IN_SERVICE_FLAG,
 106 +                              controller->base + QUP_OPERATIONAL);
 107 +
 108 +               if (is_block_mode) {
 109 +                       num_words = (remainder > words_per_block) ?
 110 +                                       words_per_block : remainder;
 111 +               } else {
 112 +                       if (!spi_qup_is_flag_set(controller,
 113 +                                                QUP_OP_IN_FIFO_NOT_EMPTY))
 114 +                               break;
 115
 116 -       w_size = controller->w_size;
 117 +                       num_words = 1;
 118 +               }
 119 +
 120 +               /* read up to the maximum transfer size available */
 121 +               spi_qup_read_from_fifo(controller, xfer, num_words);
 122
 123 -       while (controller->tx_bytes < xfer->len) {
 124 +               remainder -= num_words;
 125
 126 -               state = readl_relaxed(controller->base + QUP_OPERATIONAL);
 127 -               if (state & QUP_OP_OUT_FIFO_FULL)
 128 +               /* if block mode, check to see if next block is available */
 129 +               if (is_block_mode && !spi_qup_is_flag_set(controller,
 130 +                                       QUP_OP_IN_BLOCK_READ_REQ))
 131                         break;
 132
 133 +       } while (remainder);
 134 +
 135 +       /*
 136 +        * Due to extra stickiness of the QUP_OP_IN_SERVICE_FLAG during block
 137 +        * mode reads, it has to be cleared again at the very end
 138 +        */
 139 +       if (is_block_mode && spi_qup_is_flag_set(controller,
 140 +                               QUP_OP_MAX_INPUT_DONE_FLAG))
 141 +               writel_relaxed(QUP_OP_IN_SERVICE_FLAG,
 142 +                              controller->base + QUP_OPERATIONAL);
 143 +
 144 +}
 145 +
 146 +static void spi_qup_write_to_fifo(struct spi_qup *controller,
 147 +       struct spi_transfer *xfer, u32 num_words)
 148 +{
 149 +       const u8 *tx_buf = xfer->tx_buf;
 150 +       int i, num_bytes;
 151 +       u32 word, data;
 152 +
 153 +       for (; num_words; num_words--) {
 154                 word = 0;
 155 -               for (idx = 0; idx < w_size; idx++, controller->tx_bytes++) {
 156
 157 -                       if (!tx_buf) {
 158 -                               controller->tx_bytes += w_size;
 159 -                               break;
 160 +               num_bytes = min_t(int, xfer->len - controller->tx_bytes,
 161 +                                   controller->w_size);
 162 +               if (tx_buf)
 163 +                       for (i = 0; i < num_bytes; i++) {
 164 +                               data = tx_buf[controller->tx_bytes + i];
 165 +                               word |= data << (BITS_PER_BYTE * (3 - i));
 166                         }
 167
 168 -                       data = tx_buf[controller->tx_bytes];
 169 -                       word |= data << (BITS_PER_BYTE * (3 - idx));
 170 -               }
 171 +               controller->tx_bytes += num_bytes;
 172
 173                 writel_relaxed(word, controller->base + QUP_OUTPUT_FIFO);
 174         }
 175 @@ -290,6 +337,44 @@ static void spi_qup_dma_done(void *data)
 176         complete(done);
 177  }
 178
 179 +static void spi_qup_write(struct spi_qup *controller,
 180 +                           struct spi_transfer *xfer)
 181 +{
 182 +       bool is_block_mode = controller->mode == QUP_IO_M_MODE_BLOCK;
 183 +       u32 remainder, words_per_block, num_words;
 184 +
 185 +       remainder = DIV_ROUND_UP(xfer->len - controller->tx_bytes,
 186 +                                controller->w_size);
 187 +       words_per_block = controller->out_blk_sz >> 2;
 188 +
 189 +       do {
 190 +               /* ACK by clearing service flag */
 191 +               writel_relaxed(QUP_OP_OUT_SERVICE_FLAG,
 192 +                              controller->base + QUP_OPERATIONAL);
 193 +
 194 +               if (is_block_mode) {
 195 +                       num_words = (remainder > words_per_block) ?
 196 +                               words_per_block : remainder;
 197 +               } else {
 198 +                       if (spi_qup_is_flag_set(controller,
 199 +                                               QUP_OP_OUT_FIFO_FULL))
 200 +                               break;
 201 +
 202 +                       num_words = 1;
 203 +               }
 204 +
 205 +               spi_qup_write_to_fifo(controller, xfer, num_words);
 206 +
 207 +               remainder -= num_words;
 208 +
 209 +               /* if block mode, check to see if next block is available */
 210 +               if (is_block_mode && !spi_qup_is_flag_set(controller,
 211 +                                       QUP_OP_OUT_BLOCK_WRITE_REQ))
 212 +                       break;
 213 +
 214 +       } while (remainder);
 215 +}
 216 +
 217  static int spi_qup_prep_sg(struct spi_master *master, struct spi_transfer *xfer,
 218                            enum dma_transfer_direction dir,
 219                            dma_async_tx_callback callback,
 220 @@ -347,11 +432,13 @@ unsigned long timeout)
 221                 return ret;
 222         }
 223
 224 -       if (xfer->rx_buf)
 225 -               rx_done = spi_qup_dma_done;
 226 +       if (!qup->qup_v1) {
 227 +               if (xfer->rx_buf)
 228 +                       rx_done = spi_qup_dma_done;
 229
 230 -       if (xfer->tx_buf)
 231 -               tx_done = spi_qup_dma_done;
 232 +               if (xfer->tx_buf)
 233 +                       tx_done = spi_qup_dma_done;
 234 +       }
 235
 236         if (xfer->rx_buf) {
 237                 ret = spi_qup_prep_sg(master, xfer, DMA_DEV_TO_MEM, rx_done,
 238 @@ -398,7 +485,8 @@ static int spi_qup_do_pio(struct spi_mas
 239                 return ret;
 240         }
 241
 242 -       spi_qup_fifo_write(qup, xfer);
 243 +       if (qup->mode == QUP_IO_M_MODE_FIFO)
 244 +               spi_qup_write(qup, xfer);
 245
 246         ret = spi_qup_set_state(qup, QUP_STATE_RUN);
 247         if (ret) {
 248 @@ -431,10 +519,11 @@ static irqreturn_t spi_qup_qup_irq(int i
 249
 250         writel_relaxed(qup_err, controller->base + QUP_ERROR_FLAGS);
 251         writel_relaxed(spi_err, controller->base + SPI_ERROR_FLAGS);
 252 -       writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
 253
 254         if (!xfer) {
 255 -               dev_err_ratelimited(controller->dev, "unexpected irq %08x %08x %08x\n",
 256 +               writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
 257 +               dev_err_ratelimited(controller->dev,
 258 +                                   "unexpected irq %08x %08x %08x\n",
 259                                     qup_err, spi_err, opflags);
 260                 return IRQ_HANDLED;
 261         }
 262 @@ -460,12 +549,20 @@ static irqreturn_t spi_qup_qup_irq(int i
 263                 error = -EIO;
 264         }
 265
 266 -       if (!spi_qup_is_dma_xfer(controller->mode)) {
 267 +       if (spi_qup_is_dma_xfer(controller->mode)) {
 268 +               writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
 269 +               if (opflags & QUP_OP_IN_SERVICE_FLAG &&
 270 +                   opflags & QUP_OP_MAX_INPUT_DONE_FLAG)
 271 +                       complete(&controller->done);
 272 +               if (opflags & QUP_OP_OUT_SERVICE_FLAG &&
 273 +                   opflags & QUP_OP_MAX_OUTPUT_DONE_FLAG)
 274 +                       complete(&controller->dma_tx_done);
 275 +       } else {
 276                 if (opflags & QUP_OP_IN_SERVICE_FLAG)
 277 -                       spi_qup_fifo_read(controller, xfer);
 278 +                       spi_qup_read(controller, xfer);
 279
 280                 if (opflags & QUP_OP_OUT_SERVICE_FLAG)
 281 -                       spi_qup_fifo_write(controller, xfer);
 282 +                       spi_qup_write(controller, xfer);
 283         }
 284
 285         spin_lock_irqsave(&controller->lock, flags);
 286 @@ -473,6 +570,9 @@ static irqreturn_t spi_qup_qup_irq(int i
 287         controller->xfer = xfer;
 288         spin_unlock_irqrestore(&controller->lock, flags);
 289
 290 +       /* re-read opflags as flags may have changed due to actions above */
 291 +       opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
 292 +
 293         if ((controller->rx_bytes == xfer->len &&
 294                 (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) ||  error)
 295                 complete(&controller->done);
 296 @@ -516,11 +616,13 @@ static int spi_qup_io_config(struct spi_
 297                 /* must be zero for FIFO */
 298                 writel_relaxed(0, controller->base + QUP_MX_INPUT_CNT);
 299                 writel_relaxed(0, controller->base + QUP_MX_OUTPUT_CNT);
 300 -
 301         } else if (spi->master->can_dma &&
 302             spi->master->can_dma(spi->master, spi, xfer) &&
 303             spi->master->cur_msg_mapped) {
 304                 controller->mode = QUP_IO_M_MODE_BAM;
 305 +               writel_relaxed(n_words, controller->base + QUP_MX_INPUT_CNT);
 306 +               writel_relaxed(n_words, controller->base + QUP_MX_OUTPUT_CNT);
 307 +               /* must be zero for BLOCK and BAM */
 308                 writel_relaxed(0, controller->base + QUP_MX_READ_CNT);
 309                 writel_relaxed(0, controller->base + QUP_MX_WRITE_CNT);
 310