Re: [PATCH v11 2/3] fpga: microchip-spi: add Microchip MPF FPGA manager

From: Conor.Dooley
Date: Mon May 09 2022 - 07:41:30 EST


Hey Ivan, one comment below.
Thanks,
Conor.

On 07/05/2022 08:43, Ivan Bornyakov wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> Add support to the FPGA manager for programming Microchip Polarfire
> FPGAs over slave SPI interface with .dat formatted bitsream image.
>
> Signed-off-by: Ivan Bornyakov <i.bornyakov@xxxxxxxxxxx>
> ---
> drivers/fpga/Kconfig | 9 +
> drivers/fpga/Makefile | 1 +
> drivers/fpga/microchip-spi.c | 370 +++++++++++++++++++++++++++++++++++
> 3 files changed, 380 insertions(+)
> create mode 100644 drivers/fpga/microchip-spi.c
>
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index 26025dbab353..75806ef5c9ea 100644
> --- a/drivers/fpga/Kconfig
> +++ b/drivers/fpga/Kconfig
> @@ -248,4 +248,13 @@ config FPGA_MGR_VERSAL_FPGA
> configure the programmable logic(PL).
>
> To compile this as a module, choose M here.
> +
> +config FPGA_MGR_MICROCHIP_SPI
> + tristate "Microchip Polarfire SPI FPGA manager"
> + depends on SPI
> + help
> + FPGA manager driver support for Microchip Polarfire FPGAs
> + programming over slave SPI interface with .dat formatted
> + bitstream image.
> +
> endif # FPGA
> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> index e32bfa90f968..5425a15892df 100644
> --- a/drivers/fpga/Makefile
> +++ b/drivers/fpga/Makefile
> @@ -19,6 +19,7 @@ obj-$(CONFIG_FPGA_MGR_XILINX_SPI) += xilinx-spi.o
> obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA) += zynq-fpga.o
> obj-$(CONFIG_FPGA_MGR_ZYNQMP_FPGA) += zynqmp-fpga.o
> obj-$(CONFIG_FPGA_MGR_VERSAL_FPGA) += versal-fpga.o
> +obj-$(CONFIG_FPGA_MGR_MICROCHIP_SPI) += microchip-spi.o
> obj-$(CONFIG_ALTERA_PR_IP_CORE) += altera-pr-ip-core.o
> obj-$(CONFIG_ALTERA_PR_IP_CORE_PLAT) += altera-pr-ip-core-plat.o
>
> diff --git a/drivers/fpga/microchip-spi.c b/drivers/fpga/microchip-spi.c
> new file mode 100644
> index 000000000000..182471c88018
> --- /dev/null
> +++ b/drivers/fpga/microchip-spi.c
> @@ -0,0 +1,370 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Microchip Polarfire FPGA programming over slave SPI interface.
> + */
> +
> +#include <asm/unaligned.h>
> +#include <linux/delay.h>
> +#include <linux/fpga/fpga-mgr.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/spi/spi.h>
> +
> +#define MPF_SPI_ISC_ENABLE 0x0B
> +#define MPF_SPI_ISC_DISABLE 0x0C
> +#define MPF_SPI_READ_STATUS 0x00
> +#define MPF_SPI_READ_DATA 0x01
> +#define MPF_SPI_FRAME_INIT 0xAE
> +#define MPF_SPI_FRAME 0xEE
> +#define MPF_SPI_PRG_MODE 0x01
> +#define MPF_SPI_RELEASE 0x23
> +
> +#define MPF_SPI_FRAME_SIZE 16
> +
> +#define MPF_HEADER_SIZE_OFFSET 24
> +#define MPF_DATA_SIZE_OFFSET 55
> +
> +#define MPF_LOOKUP_TABLE_RECORD_SIZE 9
> +#define MPF_LOOKUP_TABLE_BLOCK_ID_OFFSET 0
> +#define MPF_LOOKUP_TABLE_BLOCK_START_OFFSET 1
> +
> +#define MPF_COMPONENTS_SIZE_ID 5
> +#define MPF_BITSTREAM_ID 8
> +
> +#define MPF_BITS_PER_COMPONENT_SIZE 22
> +
> +#define MPF_STATUS_POLL_TIMEOUT 1000
> +#define MPF_STATUS_BUSY BIT(0)
> +#define MPF_STATUS_READY BIT(1)
> +#define MPF_STATUS_SPI_VIOLATION BIT(2)
> +#define MPF_STATUS_SPI_ERROR BIT(3)
> +
> +struct mpf_priv {
> + struct spi_device *spi;
> + bool program_mode;
> +};
> +
> +static int mpf_read_status(struct spi_device *spi)
> +{
> + u8 status, status_command = MPF_SPI_READ_STATUS;
> + struct spi_transfer xfer = {
> + .tx_buf = &status_command,
> + .rx_buf = &status,
> + .len = 1,
> + };
> + int ret = spi_sync_transfer(spi, &xfer, 1);
> +
> + if ((status & MPF_STATUS_SPI_VIOLATION) ||
> + (status & MPF_STATUS_SPI_ERROR))
> + ret = -EIO;
> +
> + return ret ? : status;
> +}
> +
> +static enum fpga_mgr_states mpf_ops_state(struct fpga_manager *mgr)
> +{
> + struct mpf_priv *priv = mgr->priv;
> + struct spi_device *spi;
> + bool program_mode;
> + int status;
> +
> + spi = priv->spi;
> + program_mode = priv->program_mode;
> + status = mpf_read_status(spi);
> +
> + if (!program_mode && !status)
> + return FPGA_MGR_STATE_OPERATING;
> +
> + return FPGA_MGR_STATE_UNKNOWN;
> +}
> +
> +static int mpf_ops_parse_header(struct fpga_manager *mgr,
> + struct fpga_image_info *info,
> + const char *buf, size_t count)
> +{
> + size_t component_size_byte_num, component_size_byte_off,
> + components_size_start = 0, bitstream_start = 0,
> + block_id_offset, block_start_offset, i;
> + u8 header_size, blocks_num, block_id;
> + u32 block_start, component_size;
> + u16 components_num;
> +
> + if (!buf) {
> + dev_err(&mgr->dev, "Image buffer is not provided\n");
> + return -EINVAL;
> + }
> +
> + header_size = *(buf + MPF_HEADER_SIZE_OFFSET);
> + if (header_size > count) {
> + info->header_size = header_size;
> + return -EAGAIN;
> + }
> +
> + /*
> + * Go through look-up table to find out where actual bitstream starts
> + * and where sizes of components of the bitstream lies.
> + */
> + blocks_num = *(buf + header_size - 1);
> + block_id_offset = header_size + MPF_LOOKUP_TABLE_BLOCK_ID_OFFSET;
> + block_start_offset = header_size + MPF_LOOKUP_TABLE_BLOCK_START_OFFSET;
> +
> + header_size += blocks_num * MPF_LOOKUP_TABLE_RECORD_SIZE;
> + if (header_size > count) {
> + info->header_size = header_size;
> + return -EAGAIN;
> + }
> +
> + while (blocks_num--) {
> + block_id = *(buf + block_id_offset);
> + block_start = get_unaligned_le32(buf + block_start_offset);
> +
> + switch (block_id) {
> + case MPF_BITSTREAM_ID:
> + info->header_size = bitstream_start = block_start;
> + if (block_start > count)
> + return -EAGAIN;
> +
> + break;
> + case MPF_COMPONENTS_SIZE_ID:
> + components_size_start = block_start;
> + break;
> + default:
> + break;
> + }
> +
> + if (bitstream_start && components_size_start)
> + break;
> +
> + block_id_offset += MPF_LOOKUP_TABLE_RECORD_SIZE;
> + block_start_offset += MPF_LOOKUP_TABLE_RECORD_SIZE;
> + }
> +
> + if (!bitstream_start || !components_size_start) {
> + dev_err(&mgr->dev, "Failed to parse header look-up table\n");
> + return -EFAULT;
> + }
> +
> + /*
> + * Parse bitstream size.
> + * Sizes of components of the bitstream are 22-bits long placed next
> + * to each other. Image header should be extended by now up to where
> + * actual bitstream starts, so no need for overflow check anymore.
> + */
> + components_num = get_unaligned_le16(buf + MPF_DATA_SIZE_OFFSET);
> +
> + for (i = 0; i < components_num; i++) {
> + component_size_byte_num =
> + (i * MPF_BITS_PER_COMPONENT_SIZE) / BITS_PER_BYTE;
> + component_size_byte_off =
> + (i * MPF_BITS_PER_COMPONENT_SIZE) % BITS_PER_BYTE;
> +
> + component_size = get_unaligned_le32(buf +
> + components_size_start +
> + component_size_byte_num);
> + component_size >>= component_size_byte_off;
> + component_size &= GENMASK(MPF_BITS_PER_COMPONENT_SIZE - 1, 0);
> +
> + info->data_size += component_size * MPF_SPI_FRAME_SIZE;
> + }
> +
> + return 0;
> +}
> +
> +static int poll_status_not_busy(struct spi_device *spi, u8 mask)
> +{
> + int status, timeout = MPF_STATUS_POLL_TIMEOUT;
> +
> + while (timeout--) {
> + status = mpf_read_status(spi);
> + if (status < 0 ||
> + (!(status & MPF_STATUS_BUSY) && (!mask || (status & mask))))
> + return status;
> +
> + usleep_range(1000, 2000);
> + }
> +
> + return -EBUSY;
> +}

Is there a reason you changed this from the snippet you sent me
in the responses to version 8:
static int poll_status_not_busy(struct spi_device *spi, u8 mask)
{
u8 status, status_command = MPF_SPI_READ_STATUS;
int ret, timeout = MPF_STATUS_POLL_TIMEOUT;
struct spi_transfer xfer = {
.tx_buf = &status_command,
.rx_buf = &status,
.len = 1,
};

while (timeout--) {
ret = spi_sync_transfer(spi, &xfer, 1);
if (ret < 0)
return ret;

if (!(status & MPF_STATUS_BUSY) && (!mask || (status & mask)))
return status;

usleep_range(1000, 2000);
}

return -EBUSY;
}

With the current version, I hit the "Failed to write bitstream
frame" check in mpf_ops_write at random points in the transfer.
Replacing poll_status_not_busy with the above allows it to run
to completion.