Re: [PATCH v3 7/9] spi: ti-qspi: Implement the spi_mem interface

[Vignesh R <vigneshr@xxxxxx>]

On Monday 23 April 2018 12:05 AM, Boris Brezillon wrote:
> The spi_mem interface is meant to replace the spi_flash_read() one.
> Implement the ->exec_op() method so that we can smoothly get rid of the
> old interface.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
> ---
> Changes in v3:
> - none
> 
> Changes in v2:
> - include spi-mem.h
> - treat op->addr.val differently since it's now an u64
> - Fix 'buf is DMA-able' check
> - Extract max mmap size from resource_size()
> ---
>  drivers/spi/spi-ti-qspi.c | 84 +++++++++++++++++++++++++++++++++++++++--------
>  1 file changed, 71 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c
> index c24d9b45a27c..a37db01447a7 100644
> --- a/drivers/spi/spi-ti-qspi.c
> +++ b/drivers/spi/spi-ti-qspi.c
> @@ -36,6 +36,7 @@
>  #include <linux/sizes.h>
>  
>  #include <linux/spi/spi.h>
> +#include <linux/spi/spi-mem.h>
>  
>  struct ti_qspi_regs {
>  	u32 clkctrl;
> @@ -50,6 +51,7 @@ struct ti_qspi {
>  	struct spi_master	*master;
>  	void __iomem            *base;
>  	void __iomem            *mmap_base;
> +	size_t			mmap_size;
>  	struct regmap		*ctrl_base;
>  	unsigned int		ctrl_reg;
>  	struct clk		*fclk;
> @@ -434,12 +436,10 @@ static int ti_qspi_dma_xfer(struct ti_qspi *qspi, dma_addr_t dma_dst,
>  	return 0;
>  }
>  
> -static int ti_qspi_dma_bounce_buffer(struct ti_qspi *qspi,
> -				     struct spi_flash_read_message *msg)
> +static int ti_qspi_dma_bounce_buffer(struct ti_qspi *qspi, loff_t offs,
> +				     void *to, size_t readsize)
>  {
> -	size_t readsize = msg->len;
> -	void *to = msg->buf;
> -	dma_addr_t dma_src = qspi->mmap_phys_base + msg->from;
> +	dma_addr_t dma_src = qspi->mmap_phys_base + offs;
>  	int ret = 0;
>  
>  	/*
> @@ -507,13 +507,14 @@ static void ti_qspi_disable_memory_map(struct spi_device *spi)
>  	qspi->mmap_enabled = false;
>  }
>  
> -static void ti_qspi_setup_mmap_read(struct spi_device *spi,
> -				    struct spi_flash_read_message *msg)
> +static void ti_qspi_setup_mmap_read(struct spi_device *spi, u8 opcode,
> +				    u8 data_nbits, u8 addr_width,
> +				    u8 dummy_bytes)
>  {
>  	struct ti_qspi  *qspi = spi_master_get_devdata(spi->master);
> -	u32 memval = msg->read_opcode;
> +	u32 memval = opcode;
>  
> -	switch (msg->data_nbits) {
> +	switch (data_nbits) {
>  	case SPI_NBITS_QUAD:
>  		memval |= QSPI_SETUP_RD_QUAD;
>  		break;
> @@ -524,8 +525,8 @@ static void ti_qspi_setup_mmap_read(struct spi_device *spi,
>  		memval |= QSPI_SETUP_RD_NORMAL;
>  		break;
>  	}
> -	memval |= ((msg->addr_width - 1) << QSPI_SETUP_ADDR_SHIFT |
> -		   msg->dummy_bytes << QSPI_SETUP_DUMMY_SHIFT);
> +	memval |= ((addr_width - 1) << QSPI_SETUP_ADDR_SHIFT |
> +		   dummy_bytes << QSPI_SETUP_DUMMY_SHIFT);
>  	ti_qspi_write(qspi, memval,
>  		      QSPI_SPI_SETUP_REG(spi->chip_select));
>  }
> @@ -546,13 +547,15 @@ static int ti_qspi_spi_flash_read(struct spi_device *spi,
>  
>  	if (!qspi->mmap_enabled)
>  		ti_qspi_enable_memory_map(spi);
> -	ti_qspi_setup_mmap_read(spi, msg);
> +	ti_qspi_setup_mmap_read(spi, msg->read_opcode, msg->data_nbits,
> +				msg->addr_width, msg->dummy_bytes);
>  
>  	if (qspi->rx_chan) {
>  		if (msg->cur_msg_mapped)
>  			ret = ti_qspi_dma_xfer_sg(qspi, msg->rx_sg, msg->from);
>  		else
> -			ret = ti_qspi_dma_bounce_buffer(qspi, msg);
> +			ret = ti_qspi_dma_bounce_buffer(qspi, msg->from,
> +							msg->buf, msg->len);
>  		if (ret)
>  			goto err_unlock;
>  	} else {
> @@ -566,6 +569,58 @@ 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);
> +	u32 from = 0;
> +	int ret = 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;
> +
> +	/* Address exceeds MMIO window size, fall back to regular mode. */
> +	from = op->addr.val;
> +	if (from + op->data.nbytes > qspi->mmap_size)
> +		return -ENOTSUPP;
> +

qspi->mmap_size turns out to be 0 if qspi->rx_chan is not NULL
(in other words when DMA is used)
Could you squash below diff into this patch?

===========

diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c
index 694902dd6f70..c54b760e00ed 100644
--- a/drivers/spi/spi-ti-qspi.c
+++ b/drivers/spi/spi-ti-qspi.c
@@ -718,6 +718,7 @@ static int ti_qspi_probe(struct platform_device *pdev)
                                "memory mapped resource not required\n");
                }
        }
+       qspi->mmap_size = resource_size(res_mmap);
 
        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
@@ -794,7 +795,6 @@ static int ti_qspi_probe(struct platform_device *pdev)
 
 no_dma:
        if (!qspi->rx_chan && res_mmap) {
-               qspi->mmap_size = resource_size(res_mmap);
                qspi->mmap_base = devm_ioremap_resource(&pdev->dev, res_mmap);
                if (IS_ERR(qspi->mmap_base)) {
                        dev_info(&pdev->dev,



> +	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)) {
> +			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 +728,7 @@ 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;
> @@ -778,6 +834,7 @@ static int ti_qspi_probe(struct platform_device *pdev)
>  
>  no_dma:
>  	if (!qspi->rx_chan && res_mmap) {
> +		qspi->mmap_size = resource_size(res_mmap);
>  		qspi->mmap_base = devm_ioremap_resource(&pdev->dev, res_mmap);
>  		if (IS_ERR(qspi->mmap_base)) {
>  			dev_info(&pdev->dev,
> @@ -785,6 +842,7 @@ 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;
> 

-- 
Regards
Vignesh
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