Re: [RFC PATCH 4/6] spi: ti-qspi: Implement the spi_mem interface

Boris Brezillon
2018-02-16T10:26:37Z

On Tue, 6 Feb 2018 00:21:18 +0100
Boris Brezillon <boris.brezillon@bootlin.com> wrote:

> @@ -566,6 +567,62 @@ static int ti_qspi_spi_flash_read(struct spi_device *spi,
> return ret;
> }
>
> +static int ti_qspi_exec_mem_op(struct spi_mem *mem,
> + const struct spi_mem_op *op)
> +{
> + struct ti_qspi *qspi = spi_master_get_devdata(mem->spi->master);
> + int i, ret = 0;
> + u32 from = 0;
> +
> + /* Only optimize read path. */
> + if (!op->data.nbytes || op->data.dir != SPI_MEM_DATA_IN ||
> + !op->addr.nbytes || op->addr.nbytes > 4)
> + return -ENOTSUPP;
> +
> + for (i = 0; i < op->addr.nbytes; i++) {
> + from <<= 8;
> + from |= op->addr.buf[i];
> + }
> +
> + /* Address exceeds MMIO window size, fall back to regular mode. */
> + if (from > 0x4000000)
> + return -ENOTSUPP;
> +
> + mutex_lock(&qspi->list_lock);
> +
> + if (!qspi->mmap_enabled)
> + ti_qspi_enable_memory_map(mem->spi);
> + ti_qspi_setup_mmap_read(mem->spi, op->cmd.opcode, op->data.buswidth,
> + op->addr.nbytes, op->dummy.nbytes);
> +
> + if (qspi->rx_chan) {
> + struct sg_table sgt;
> +
> + if (!virt_addr_valid(op->data.buf.in) &&
> + !spi_controller_dma_map_mem_op_data(mem->spi->master, op,
> + &sgt)) {

As Vignesh just reported, it should be virt_addr_valid(op->data.buf.in)
and not !virt_addr_valid(op->data.buf.in).

> + ret = ti_qspi_dma_xfer_sg(qspi, sgt, from);
> + spi_controller_dma_unmap_mem_op_data(mem->spi->master,
> + op, &sgt);
> + } else {
> + ret = ti_qspi_dma_bounce_buffer(qspi, from,
> + op->data.buf.in,
> + op->data.nbytes);
> + }
> + } else {
> + memcpy_fromio(op->data.buf.in, qspi->mmap_base + from,
> + op->data.nbytes);
> + }
> +
> + mutex_unlock(&qspi->list_lock);
> +
> + return ret;
> +}
> +
> +static const struct spi_controller_mem_ops ti_qspi_mem_ops = {
> + .exec_op = ti_qspi_exec_mem_op,
> +};
> +
> static int ti_qspi_start_transfer_one(struct spi_master *master,
> struct spi_message *m)
> {
> @@ -673,6 +730,7 @@ static int ti_qspi_probe(struct platform_device *pdev)
> master->bits_per_word_mask = SPI_BPW_MASK(32) | SPI_BPW_MASK(16) |
> SPI_BPW_MASK(8);
> master->spi_flash_read = ti_qspi_spi_flash_read;
> + master->mem_ops = &ti_qspi_mem_ops;
>
> if (!of_property_read_u32(np, "num-cs", &num_cs))
> master->num_chipselect = num_cs;
> @@ -785,6 +843,7 @@ static int ti_qspi_probe(struct platform_device *pdev)
> PTR_ERR(qspi->mmap_base));
> qspi->mmap_base = NULL;
> master->spi_flash_read = NULL;
> + master->mem_ops = NULL;
> }
> }
> qspi->mmap_enabled = false;

--
Boris Brezillon, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering