target/linux/ipq806x/patches-4.9/0008-spi-qup-Fix-DMA-mode-to-work-correctly.patch

   1 From 715d008b67b21fb8bfefaeeefa5b8ddf23777872 Mon Sep 17 00:00:00 2001
   2 From: Andy Gross <andy.gross@linaro.org>
   3 Date: Tue, 2 Feb 2016 17:00:53 -0600
   4 Subject: [PATCH 08/37] spi: qup: Fix DMA mode to work correctly
   5
   6 This patch fixes a few issues with the DMA mode.  The QUP needs to be
   7 placed in the run mode before the DMA transactions are executed.  The
   8 conditions for being able to DMA vary between revisions of the QUP.
   9 This is due to v1.1.1 using ADM DMA and later revisions using BAM.
  10
  11 Signed-off-by: Andy Gross <andy.gross@linaro.org>
  12 ---
  13  drivers/spi/spi-qup.c |   94 ++++++++++++++++++++++++++++++++-----------------
  14  1 file changed, 62 insertions(+), 32 deletions(-)
  15
  16 --- a/drivers/spi/spi-qup.c
  17 +++ b/drivers/spi/spi-qup.c
  18 @@ -142,6 +142,7 @@ struct spi_qup {
  19
  20         struct spi_transfer     *xfer;
  21         struct completion       done;
  22 +       struct completion       dma_tx_done;
  23         int                     error;
  24         int                     w_size; /* bytes per SPI word */
  25         int                     n_words;
  26 @@ -284,16 +285,16 @@ static void spi_qup_fifo_write(struct sp
  27
  28  static void spi_qup_dma_done(void *data)
  29  {
  30 -       struct spi_qup *qup = data;
  31 +       struct completion *done = data;
  32
  33 -       complete(&qup->done);
  34 +       complete(done);
  35  }
  36
  37  static int spi_qup_prep_sg(struct spi_master *master, struct spi_transfer *xfer,
  38                            enum dma_transfer_direction dir,
  39 -                          dma_async_tx_callback callback)
  40 +                          dma_async_tx_callback callback,
  41 +                          void *data)
  42  {
  43 -       struct spi_qup *qup = spi_master_get_devdata(master);
  44         unsigned long flags = DMA_PREP_INTERRUPT | DMA_PREP_FENCE;
  45         struct dma_async_tx_descriptor *desc;
  46         struct scatterlist *sgl;
  47 @@ -312,11 +313,11 @@ static int spi_qup_prep_sg(struct spi_ma
  48         }
  49
  50         desc = dmaengine_prep_slave_sg(chan, sgl, nents, dir, flags);
  51 -       if (!desc)
  52 -               return -EINVAL;
  53 +       if (IS_ERR_OR_NULL(desc))
  54 +               return desc ? PTR_ERR(desc) : -EINVAL;
  55
  56         desc->callback = callback;
  57 -       desc->callback_param = qup;
  58 +       desc->callback_param = data;
  59
  60         cookie = dmaengine_submit(desc);
  61
  62 @@ -332,18 +333,29 @@ static void spi_qup_dma_terminate(struct
  63                 dmaengine_terminate_all(master->dma_rx);
  64  }
  65
  66 -static int spi_qup_do_dma(struct spi_master *master, struct spi_transfer *xfer)
  67 +static int spi_qup_do_dma(struct spi_master *master, struct spi_transfer *xfer,
  68 +unsigned long timeout)
  69  {
  70 +       struct spi_qup *qup = spi_master_get_devdata(master);
  71         dma_async_tx_callback rx_done = NULL, tx_done = NULL;
  72         int ret;
  73
  74 +       /* before issuing the descriptors, set the QUP to run */
  75 +       ret = spi_qup_set_state(qup, QUP_STATE_RUN);
  76 +       if (ret) {
  77 +               dev_warn(qup->dev, "cannot set RUN state\n");
  78 +               return ret;
  79 +       }
  80 +
  81         if (xfer->rx_buf)
  82                 rx_done = spi_qup_dma_done;
  83 -       else if (xfer->tx_buf)
  84 +
  85 +       if (xfer->tx_buf)
  86                 tx_done = spi_qup_dma_done;
  87
  88         if (xfer->rx_buf) {
  89 -               ret = spi_qup_prep_sg(master, xfer, DMA_DEV_TO_MEM, rx_done);
  90 +               ret = spi_qup_prep_sg(master, xfer, DMA_DEV_TO_MEM, rx_done,
  91 +                                     &qup->done);
  92                 if (ret)
  93                         return ret;
  94
  95 @@ -351,17 +363,25 @@ static int spi_qup_do_dma(struct spi_mas
  96         }
  97
  98         if (xfer->tx_buf) {
  99 -               ret = spi_qup_prep_sg(master, xfer, DMA_MEM_TO_DEV, tx_done);
 100 +               ret = spi_qup_prep_sg(master, xfer, DMA_MEM_TO_DEV, tx_done,
 101 +                                     &qup->dma_tx_done);
 102                 if (ret)
 103                         return ret;
 104
 105                 dma_async_issue_pending(master->dma_tx);
 106         }
 107
 108 -       return 0;
 109 +       if (xfer->rx_buf && !wait_for_completion_timeout(&qup->done, timeout))
 110 +               return -ETIMEDOUT;
 111 +
 112 +       if (xfer->tx_buf && !wait_for_completion_timeout(&qup->dma_tx_done, timeout))
 113 +               ret = -ETIMEDOUT;
 114 +
 115 +       return ret;
 116  }
 117
 118 -static int spi_qup_do_pio(struct spi_master *master, struct spi_transfer *xfer)
 119 +static int spi_qup_do_pio(struct spi_master *master, struct spi_transfer *xfer,
 120 +                         unsigned long timeout)
 121  {
 122         struct spi_qup *qup = spi_master_get_devdata(master);
 123         int ret;
 124 @@ -380,6 +400,15 @@ static int spi_qup_do_pio(struct spi_mas
 125
 126         spi_qup_fifo_write(qup, xfer);
 127
 128 +       ret = spi_qup_set_state(qup, QUP_STATE_RUN);
 129 +       if (ret) {
 130 +               dev_warn(qup->dev, "cannot set RUN state\n");
 131 +               return ret;
 132 +       }
 133 +
 134 +       if (!wait_for_completion_timeout(&qup->done, timeout))
 135 +               return -ETIMEDOUT;
 136 +
 137         return 0;
 138  }
 139
 140 @@ -428,7 +457,6 @@ static irqreturn_t spi_qup_qup_irq(int i
 141                         dev_warn(controller->dev, "CLK_OVER_RUN\n");
 142                 if (spi_err & SPI_ERROR_CLK_UNDER_RUN)
 143                         dev_warn(controller->dev, "CLK_UNDER_RUN\n");
 144 -
 145                 error = -EIO;
 146         }
 147
 148 @@ -617,6 +645,7 @@ static int spi_qup_transfer_one(struct s
 149         timeout = 100 * msecs_to_jiffies(timeout);
 150
 151         reinit_completion(&controller->done);
 152 +       reinit_completion(&controller->dma_tx_done);
 153
 154         spin_lock_irqsave(&controller->lock, flags);
 155         controller->xfer     = xfer;
 156 @@ -626,21 +655,13 @@ static int spi_qup_transfer_one(struct s
 157         spin_unlock_irqrestore(&controller->lock, flags);
 158
 159         if (spi_qup_is_dma_xfer(controller->mode))
 160 -               ret = spi_qup_do_dma(master, xfer);
 161 +               ret = spi_qup_do_dma(master, xfer, timeout);
 162         else
 163 -               ret = spi_qup_do_pio(master, xfer);
 164 +               ret = spi_qup_do_pio(master, xfer, timeout);
 165
 166         if (ret)
 167                 goto exit;
 168
 169 -       if (spi_qup_set_state(controller, QUP_STATE_RUN)) {
 170 -               dev_warn(controller->dev, "cannot set EXECUTE state\n");
 171 -               goto exit;
 172 -       }
 173 -
 174 -       if (!wait_for_completion_timeout(&controller->done, timeout))
 175 -               ret = -ETIMEDOUT;
 176 -
 177  exit:
 178         spi_qup_set_state(controller, QUP_STATE_RESET);
 179         spin_lock_irqsave(&controller->lock, flags);
 180 @@ -662,15 +683,23 @@ static bool spi_qup_can_dma(struct spi_m
 181         size_t dma_align = dma_get_cache_alignment();
 182         int n_words;
 183
 184 -       if (xfer->rx_buf && (xfer->len % qup->in_blk_sz ||
 185 -           IS_ERR_OR_NULL(master->dma_rx) ||
 186 -           !IS_ALIGNED((size_t)xfer->rx_buf, dma_align)))
 187 -               return false;
 188 +       if (xfer->rx_buf) {
 189 +               if (!IS_ALIGNED((size_t)xfer->rx_buf, dma_align) ||
 190 +                   IS_ERR_OR_NULL(master->dma_rx))
 191 +                       return false;
 192
 193 -       if (xfer->tx_buf && (xfer->len % qup->out_blk_sz ||
 194 -           IS_ERR_OR_NULL(master->dma_tx) ||
 195 -           !IS_ALIGNED((size_t)xfer->tx_buf, dma_align)))
 196 -               return false;
 197 +               if (qup->qup_v1 && (xfer->len % qup->in_blk_sz))
 198 +                       return false;
 199 +       }
 200 +
 201 +       if (xfer->tx_buf) {
 202 +               if (!IS_ALIGNED((size_t)xfer->tx_buf, dma_align) ||
 203 +                   IS_ERR_OR_NULL(master->dma_tx))
 204 +                       return false;
 205 +
 206 +               if (qup->qup_v1 && (xfer->len % qup->out_blk_sz))
 207 +                       return false;
 208 +       }
 209
 210         n_words = xfer->len / DIV_ROUND_UP(xfer->bits_per_word, 8);
 211         if (n_words <= (qup->in_fifo_sz / sizeof(u32)))
 212 @@ -836,6 +865,7 @@ static int spi_qup_probe(struct platform
 213
 214         spin_lock_init(&controller->lock);
 215         init_completion(&controller->done);
 216 +       init_completion(&controller->dma_tx_done);
 217
 218         iomode = readl_relaxed(base + QUP_IO_M_MODES);
 219