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

[Boris Brezillon]

On Tue,  6 Feb 2018 00:21:18 +0100
Boris Brezillon <boris.brezillon at 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
http://bootlin.com