+ struct mxs_ssp_regs *ssp_regs = priv->regs;
+#endif
+
+ if (flags & SPI_XFER_BEGIN)
+ mxs_spi_start_xfer(ssp_regs);
+
+ while (length--) {
+ /* We transfer 1 byte */
+#if defined(CONFIG_MX23)
+ writel(SSP_CTRL0_XFER_COUNT_MASK, &ssp_regs->hw_ssp_ctrl0_clr);
+ writel(1, &ssp_regs->hw_ssp_ctrl0_set);
+#elif defined(CONFIG_MX28)
+ writel(1, &ssp_regs->hw_ssp_xfer_size);
+#endif
+
+ if ((flags & SPI_XFER_END) && !length)
+ mxs_spi_end_xfer(ssp_regs);
+
+ if (write)
+ writel(SSP_CTRL0_READ, &ssp_regs->hw_ssp_ctrl0_clr);
+ else
+ writel(SSP_CTRL0_READ, &ssp_regs->hw_ssp_ctrl0_set);
+
+ writel(SSP_CTRL0_RUN, &ssp_regs->hw_ssp_ctrl0_set);
+
+ if (mxs_wait_mask_set(&ssp_regs->hw_ssp_ctrl0_reg,
+ SSP_CTRL0_RUN, MXS_SPI_MAX_TIMEOUT)) {
+ printf("MXS SPI: Timeout waiting for start\n");
+ return -ETIMEDOUT;
+ }
+
+ if (write)
+ writel(*data++, &ssp_regs->hw_ssp_data);
+
+ writel(SSP_CTRL0_DATA_XFER, &ssp_regs->hw_ssp_ctrl0_set);
+
+ if (!write) {
+ if (mxs_wait_mask_clr(&ssp_regs->hw_ssp_status_reg,
+ SSP_STATUS_FIFO_EMPTY, MXS_SPI_MAX_TIMEOUT)) {
+ printf("MXS SPI: Timeout waiting for data\n");
+ return -ETIMEDOUT;
+ }
+
+ *data = readl(&ssp_regs->hw_ssp_data);
+ data++;
+ }
+
+ if (mxs_wait_mask_clr(&ssp_regs->hw_ssp_ctrl0_reg,
+ SSP_CTRL0_RUN, MXS_SPI_MAX_TIMEOUT)) {
+ printf("MXS SPI: Timeout waiting for finish\n");
+ return -ETIMEDOUT;
+ }
+ }
+
+ return 0;
+}
+
+#if !CONFIG_IS_ENABLED(DM_SPI)
+static int mxs_spi_xfer_dma(struct mxs_spi_slave *slave,
+ char *data, int length, int write, unsigned long flags)
+{
+ struct mxs_ssp_regs *ssp_regs = slave->regs;
+#else
+static int mxs_spi_xfer_dma(struct mxs_spi_priv *priv,
+ char *data, int length, int write,
+ unsigned long flags)
+{ struct mxs_ssp_regs *ssp_regs = priv->regs;
+#endif
+ const int xfer_max_sz = 0xff00;
+ const int desc_count = DIV_ROUND_UP(length, xfer_max_sz) + 1;
+ struct mxs_dma_desc *dp;
+ uint32_t ctrl0;
+ uint32_t cache_data_count;
+ const uint32_t dstart = (uint32_t)data;
+ int dmach;
+ int tl;
+ int ret = 0;
+
+#if defined(CONFIG_MX23)
+ const int mxs_spi_pio_words = 1;
+#elif defined(CONFIG_MX28)
+ const int mxs_spi_pio_words = 4;
+#endif
+
+ ALLOC_CACHE_ALIGN_BUFFER(struct mxs_dma_desc, desc, desc_count);
+
+ memset(desc, 0, sizeof(struct mxs_dma_desc) * desc_count);
+
+ ctrl0 = readl(&ssp_regs->hw_ssp_ctrl0);
+ ctrl0 |= SSP_CTRL0_DATA_XFER;
+
+ if (flags & SPI_XFER_BEGIN)
+ ctrl0 |= SSP_CTRL0_LOCK_CS;
+ if (!write)
+ ctrl0 |= SSP_CTRL0_READ;
+
+ if (length % ARCH_DMA_MINALIGN)
+ cache_data_count = roundup(length, ARCH_DMA_MINALIGN);
+ else
+ cache_data_count = length;
+
+ /* Flush data to DRAM so DMA can pick them up */
+ if (write)
+ flush_dcache_range(dstart, dstart + cache_data_count);
+
+ /* Invalidate the area, so no writeback into the RAM races with DMA */
+ invalidate_dcache_range(dstart, dstart + cache_data_count);
+
+#if !CONFIG_IS_ENABLED(DM_SPI)
+ dmach = MXS_DMA_CHANNEL_AHB_APBH_SSP0 + slave->slave.bus;
+#else
+ dmach = priv->dma_channel;
+#endif
+
+ dp = desc;
+ while (length) {
+ dp->address = (dma_addr_t)dp;
+ dp->cmd.address = (dma_addr_t)data;
+
+ /*
+ * This is correct, even though it does indeed look insane.
+ * I hereby have to, wholeheartedly, thank Freescale Inc.,
+ * for always inventing insane hardware and keeping me busy
+ * and employed ;-)
+ */
+ if (write)
+ dp->cmd.data = MXS_DMA_DESC_COMMAND_DMA_READ;
+ else
+ dp->cmd.data = MXS_DMA_DESC_COMMAND_DMA_WRITE;
+
+ /*
+ * The DMA controller can transfer large chunks (64kB) at
+ * time by setting the transfer length to 0. Setting tl to
+ * 0x10000 will overflow below and make .data contain 0.
+ * Otherwise, 0xff00 is the transfer maximum.
+ */
+ if (length >= 0x10000)
+ tl = 0x10000;
+ else
+ tl = min(length, xfer_max_sz);
+
+ dp->cmd.data |=
+ ((tl & 0xffff) << MXS_DMA_DESC_BYTES_OFFSET) |
+ (mxs_spi_pio_words << MXS_DMA_DESC_PIO_WORDS_OFFSET) |
+ MXS_DMA_DESC_HALT_ON_TERMINATE |
+ MXS_DMA_DESC_TERMINATE_FLUSH;
+
+ data += tl;
+ length -= tl;
+
+ if (!length) {
+ dp->cmd.data |= MXS_DMA_DESC_IRQ | MXS_DMA_DESC_DEC_SEM;
+
+ if (flags & SPI_XFER_END) {
+ ctrl0 &= ~SSP_CTRL0_LOCK_CS;
+ ctrl0 |= SSP_CTRL0_IGNORE_CRC;
+ }
+ }
+
+ /*
+ * Write CTRL0, CMD0, CMD1 and XFER_SIZE registers in
+ * case of MX28, write only CTRL0 in case of MX23 due
+ * to the difference in register layout. It is utterly
+ * essential that the XFER_SIZE register is written on
+ * a per-descriptor basis with the same size as is the
+ * descriptor!
+ */
+ dp->cmd.pio_words[0] = ctrl0;
+#ifdef CONFIG_MX28
+ dp->cmd.pio_words[1] = 0;
+ dp->cmd.pio_words[2] = 0;
+ dp->cmd.pio_words[3] = tl;
+#endif
+
+ mxs_dma_desc_append(dmach, dp);
+
+ dp++;
+ }
+
+ if (mxs_dma_go(dmach))
+ ret = -EINVAL;
+
+ /* The data arrived into DRAM, invalidate cache over them */
+ if (!write)
+ invalidate_dcache_range(dstart, dstart + cache_data_count);
+
+ return ret;