On Tue, Jan 23, 2024 at 9:34 AM Tudor Ambarus <tudor.ambarus@xxxxxxxxxx> wrote:
>
> Add support for GS101 SPI. All the SPI nodes on GS101 have 64 bytes
> FIFOs, infer the FIFO size from the compatible. GS101 allows just 32bit
> register accesses, otherwise a Serror Interrupt is raised. Do the write
> reg accesses in 32 bits.
>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx>
> ---
I counted 3 different features in this patch. Would be better to split
it correspondingly into 3 patches, to make patches atomic:
1. I/O width
2. FIFO size
3. Adding support for gs101
And I'm not really convinced about FIFO size change.
> drivers/spi/spi-s3c64xx.c | 50 +++++++++++++++++++++++++++++++++------
> 1 file changed, 43 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
> index 62671b2d594a..c4ddd2859ba4 100644
> --- a/drivers/spi/spi-s3c64xx.c
> +++ b/drivers/spi/spi-s3c64xx.c
> @@ -20,6 +20,7 @@
>
> #define MAX_SPI_PORTS 12
> #define S3C64XX_SPI_QUIRK_CS_AUTO BIT(1)
> +#define S3C64XX_SPI_GS1O1_32BIT_REG_IO_WIDTH BIT(2)
> #define AUTOSUSPEND_TIMEOUT 2000
>
> /* Registers and bit-fields */
> @@ -131,6 +132,7 @@ struct s3c64xx_spi_dma_data {
> * @rx_lvl_offset: Bit offset of RX_FIFO_LVL bits in SPI_STATUS regiter.
> * @tx_st_done: Bit offset of TX_DONE bit in SPI_STATUS regiter.
> * @clk_div: Internal clock divider
> + * @fifosize: size of the FIFO
> * @quirks: Bitmask of known quirks
> * @high_speed: True, if the controller supports HIGH_SPEED_EN bit.
> * @clk_from_cmu: True, if the controller does not include a clock mux and
> @@ -149,6 +151,7 @@ struct s3c64xx_spi_port_config {
> int tx_st_done;
> int quirks;
> int clk_div;
> + unsigned int fifosize;
> bool high_speed;
> bool clk_from_cmu;
> bool clk_ioclk;
> @@ -175,6 +178,7 @@ struct s3c64xx_spi_port_config {
> * @tx_dma: Local transmit DMA data (e.g. chan and direction)
> * @port_conf: Local SPI port configuartion data
> * @port_id: Port identification number
> + * @fifosize: size of the FIFO for this port
> */
> struct s3c64xx_spi_driver_data {
> void __iomem *regs;
> @@ -194,6 +198,7 @@ struct s3c64xx_spi_driver_data {
> struct s3c64xx_spi_dma_data tx_dma;
> const struct s3c64xx_spi_port_config *port_conf;
> unsigned int port_id;
> + unsigned int fifosize;
> };
>
> static void s3c64xx_flush_fifo(struct s3c64xx_spi_driver_data *sdd)
> @@ -403,7 +408,7 @@ static bool s3c64xx_spi_can_dma(struct spi_controller *host,
> struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
>
> if (sdd->rx_dma.ch && sdd->tx_dma.ch)
> - return xfer->len > FIFO_DEPTH(sdd);
> + return xfer->len > sdd->fifosize;
>
> return false;
> }
> @@ -447,12 +452,22 @@ static int s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
> xfer->tx_buf, xfer->len / 4);
> break;
> case 16:
> - iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
> - xfer->tx_buf, xfer->len / 2);
> + if (sdd->port_conf->quirks &
> + S3C64XX_SPI_GS1O1_32BIT_REG_IO_WIDTH)
> + iowrite16_32_rep(regs + S3C64XX_SPI_TX_DATA,
> + xfer->tx_buf, xfer->len / 2);
> + else
> + iowrite16_rep(regs + S3C64XX_SPI_TX_DATA,
> + xfer->tx_buf, xfer->len / 2);
> break;
> default:
> - iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
> - xfer->tx_buf, xfer->len);
> + if (sdd->port_conf->quirks &
> + S3C64XX_SPI_GS1O1_32BIT_REG_IO_WIDTH)
> + iowrite8_32_rep(regs + S3C64XX_SPI_TX_DATA,
> + xfer->tx_buf, xfer->len);
> + else
> + iowrite8_rep(regs + S3C64XX_SPI_TX_DATA,
> + xfer->tx_buf, xfer->len);
> break;
> }
> }
> @@ -696,7 +711,7 @@ static int s3c64xx_spi_transfer_one(struct spi_controller *host,
> struct spi_transfer *xfer)
> {
> struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
> - const unsigned int fifo_len = FIFO_DEPTH(sdd);
> + const unsigned int fifo_len = sdd->fifosize;
> const void *tx_buf = NULL;
> void *rx_buf = NULL;
> int target_len = 0, origin_len = 0;
> @@ -1145,6 +1160,11 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
> sdd->port_id = pdev->id;
> }
>
> + if (sdd->port_conf->fifosize)
> + sdd->fifosize = sdd->port_conf->fifosize;
> + else
> + sdd->fifosize = FIFO_DEPTH(sdd);
> +
> sdd->cur_bpw = 8;
>
> sdd->tx_dma.direction = DMA_MEM_TO_DEV;
> @@ -1234,7 +1254,7 @@ static int s3c64xx_spi_probe(struct platform_device *pdev)
> dev_dbg(&pdev->dev, "Samsung SoC SPI Driver loaded for Bus SPI-%d with %d Targets attached\n",
> sdd->port_id, host->num_chipselect);
> dev_dbg(&pdev->dev, "\tIOmem=[%pR]\tFIFO %dbytes\n",
> - mem_res, FIFO_DEPTH(sdd));
> + mem_res, sdd->fifosize);
>
> pm_runtime_mark_last_busy(&pdev->dev);
> pm_runtime_put_autosuspend(&pdev->dev);
> @@ -1362,6 +1382,18 @@ static const struct dev_pm_ops s3c64xx_spi_pm = {
> s3c64xx_spi_runtime_resume, NULL)
> };
>
> +static const struct s3c64xx_spi_port_config gs101_spi_port_config = {
> + .fifosize = 64,
I think if you rework the the .fifo_lvl_mask, replacing it with
.fifosize, you should also do next things in this series:
1. Rework it for all supported (existing) chips in this driver
2. Provide fifosize property for each SPI node for all existing dts
that use this driver
3. Get rid of .fifo_lvl_mask for good. But the compatibility with
older kernels has to be taken into the account here as well.
Otherwise it looks like a half attempt and not finished, only creating
a duplicated property/struct field for the same (already existing)
thing. Because it's completely possible to do the same using just
.fifo_lvl_mask without introducing new fields or properties. If it
seems to much -- maybe just use .fifo_lvl_mask for now, and do all
that reworking properly later, in a separate patch series?
> + .rx_lvl_offset = 15,
> + .tx_st_done = 25,
> + .clk_div = 4,
> + .high_speed = true,
> + .clk_from_cmu = true,
> + .has_loopback = true,
> + .quirks = S3C64XX_SPI_QUIRK_CS_AUTO |
> + S3C64XX_SPI_GS1O1_32BIT_REG_IO_WIDTH,
> +};
> +
> static const struct s3c64xx_spi_port_config s3c2443_spi_port_config = {
> .fifo_lvl_mask = { 0x7f },
> .rx_lvl_offset = 13,
> @@ -1452,6 +1484,10 @@ static const struct platform_device_id s3c64xx_spi_driver_ids[] = {
> };
>
> static const struct of_device_id s3c64xx_spi_dt_match[] = {
> + {
> + .compatible = "google,gs101-spi",
> + .data = &gs101_spi_port_config,
> + },
> {
> .compatible = "samsung,s3c2443-spi",
> .data = &s3c2443_spi_port_config,
> --
> 2.43.0.429.g432eaa2c6b-goog
>
