On Fri, May 13, 2022 at 07:27:54PM +0300, Ivan Bornyakov wrote:
> 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 | 371 +++++++++++++++++++++++++++++++++++
> 3 files changed, 381 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..cb59f43000a4
> --- /dev/null
> +++ b/drivers/fpga/microchip-spi.c
> @@ -0,0 +1,371 @@
> +// 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 10000
> +#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 = 0, status_command = MPF_SPI_READ_STATUS;
> + struct spi_transfer xfers[] = {
> + [0 ... 1] = {
> + .tx_buf = &status_command,
> + .rx_buf = &status,
> + .len = 1,
> + .cs_change = 1,
> + }
> + };
> + int ret = spi_sync_transfer(spi, xfers, 2);
I remember it is spi_w8r8 for the first time, why we change to
spi_sync_transfer? They behavior differently on spi bus.
And why we need to xfer the same message twice? If it relates to
some HW behavior, we'd better add some comments here.
> +
> + 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;
The initialization should be listed after declaration, so swap the 2
lines
Why the component_size_byte_num, component_size_byte_off, i should be size_t?
> + 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;
Why doesn't check the components_size_start against count, any difference
with bitstream_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);
Some check against count?
> + 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)
The function name is confusing, it does more than polling busy bit.
mpf_poll_status is better?
> +{
> + int status, timeout = MPF_STATUS_POLL_TIMEOUT;
> +
> + while (timeout--) {
> + status = mpf_read_status(spi);
> + if (status < 0 ||
> + (!(status & MPF_STATUS_BUSY) && (!mask || (status & mask))))
Please make the judgements easier to read.
if (status < 0)
return status;
if (status & MPF_STATUS_BUSY)
continue;
if (!mask || (status & mask))
return status;
Is that OK for you?
> + return status;
> + }
> +
> + return -EBUSY;
> +}
> +
> +static int mpf_spi_write(struct spi_device *spi, const void *buf, size_t buf_size)
> +{
> + int status = poll_status_not_busy(spi, 0);
> +
> + if (status < 0)
> + return status;
> +
> + return spi_write(spi, buf, buf_size);
> +}
> +
> +static int mpf_spi_write_then_read(struct spi_device *spi,
> + const void *txbuf, size_t txbuf_size,
> + void *rxbuf, size_t rxbuf_size)
> +{
> + const u8 read_command[] = { MPF_SPI_READ_DATA };
> + int ret;
> +
> + ret = mpf_spi_write(spi, txbuf, txbuf_size);
> + if (ret)
> + return ret;
> +
> + ret = poll_status_not_busy(spi, MPF_STATUS_READY);
> + if (ret < 0)
> + return ret;
> +
> + return spi_write_then_read(spi, read_command, sizeof(read_command),
> + rxbuf, rxbuf_size);
> +}
> +
> +static int mpf_ops_write_init(struct fpga_manager *mgr,
> + struct fpga_image_info *info, const char *buf,
> + size_t count)
> +{
> + const u8 program_mode[] = { MPF_SPI_FRAME_INIT, MPF_SPI_PRG_MODE };
> + const u8 isc_en_command[] = { MPF_SPI_ISC_ENABLE };
> + struct mpf_priv *priv = mgr->priv;
> + struct device *dev = &mgr->dev;
> + struct spi_device *spi;
> + u32 isc_ret;
> + int ret;
> +
> + if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
> + dev_err(dev, "Partial reconfiguration is not supported\n");
> + return -EOPNOTSUPP;
> + }
> +
> + spi = priv->spi;
> +
> + ret = mpf_spi_write_then_read(spi, isc_en_command, sizeof(isc_en_command),
> + &isc_ret, sizeof(isc_ret));
> + if (ret || isc_ret) {
> + dev_err(dev, "Failed to enable ISC: %d\n", ret ? : isc_ret);
%d for a u32 variable? Maybe just list the 2 values.
> + return -EFAULT;
> + }
> +
> + ret = mpf_spi_write(spi, program_mode, sizeof(program_mode));
> + if (ret) {
> + dev_err(dev, "Failed to enter program mode: %d\n", ret);
> + return ret;
> + }
> +
> + priv->program_mode = true;
> +
> + return 0;
> +}
> +
> +static int mpf_ops_write(struct fpga_manager *mgr, const char *buf, size_t count)
> +{
> + u8 tmp_buf[MPF_SPI_FRAME_SIZE + 1] = { MPF_SPI_FRAME, };
> + struct mpf_priv *priv = mgr->priv;
> + struct device *dev = &mgr->dev;
> + struct spi_device *spi;
> + int ret, i;
> +
> + if (count % MPF_SPI_FRAME_SIZE) {
> + dev_err(dev, "Bitstream size is not a multiple of %d\n",
> + MPF_SPI_FRAME_SIZE);
> + return -EINVAL;
> + }
> +
> + spi = priv->spi;
> +
> + for (i = 0; i < count / MPF_SPI_FRAME_SIZE; i++) {
> + memcpy(tmp_buf + 1, buf + i * MPF_SPI_FRAME_SIZE,
> + MPF_SPI_FRAME_SIZE);
> +
> + ret = mpf_spi_write(spi, tmp_buf, sizeof(tmp_buf));
As I mentioned before, is it possible we use spi_sync_transfer to avoid
memcpy the whole bitstream?
> + if (ret) {
> + dev_err(dev, "Failed to write bitstream frame %d/%zd\n",
%zu for size_t
> + i, count / MPF_SPI_FRAME_SIZE);
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int mpf_ops_write_complete(struct fpga_manager *mgr,
> + struct fpga_image_info *info)
> +{
> + const u8 isc_dis_command[] = { MPF_SPI_ISC_DISABLE };
> + const u8 release_command[] = { MPF_SPI_RELEASE };
> + struct mpf_priv *priv = mgr->priv;
> + struct device *dev = &mgr->dev;
> + struct spi_device *spi;
> + int ret;
> +
> + spi = priv->spi;
> +
> + ret = mpf_spi_write(spi, isc_dis_command, sizeof(isc_dis_command));
> + if (ret) {
> + dev_err(dev, "Failed to disable ISC: %d\n", ret);
> + return ret;
> + }
> +
> + usleep_range(1000, 2000);
> +
> + ret = mpf_spi_write(spi, release_command, sizeof(release_command));
> + if (ret) {
> + dev_err(dev, "Failed to exit program mode: %d\n", ret);
> + return ret;
> + }
> +
> + priv->program_mode = false;
> +
> + return 0;
> +}
> +
> +static const struct fpga_manager_ops mpf_ops = {
> + .state = mpf_ops_state,
> + .initial_header_size = 71,
> + .parse_header = mpf_ops_parse_header,
> + .write_init = mpf_ops_write_init,
> + .write = mpf_ops_write,
> + .write_complete = mpf_ops_write_complete,
> +};
> +
> +static int mpf_probe(struct spi_device *spi)
> +{
> + struct device *dev = &spi->dev;
> + struct fpga_manager *mgr;
> + struct mpf_priv *priv;
> +
> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->spi = spi;
> +
> + mgr = devm_fpga_mgr_register(dev, "Microchip Polarfire SPI FPGA Manager",
> + &mpf_ops, priv);
> +
> + return PTR_ERR_OR_ZERO(mgr);
> +}
> +
> +static const struct spi_device_id mpf_spi_ids[] = {
> + { .name = "mpf-spi-fpga-mgr", },
> + {},
> +};
> +MODULE_DEVICE_TABLE(spi, mpf_spi_ids);
> +
> +#if IS_ENABLED(CONFIG_OF)
> +static const struct of_device_id mpf_of_ids[] = {
> + { .compatible = "microchip,mpf-spi-fpga-mgr" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, mpf_of_ids);
> +#endif /* IS_ENABLED(CONFIG_OF) */
> +
> +static struct spi_driver mpf_driver = {
> + .probe = mpf_probe,
> + .id_table = mpf_spi_ids,
> + .driver = {
> + .name = "microchip_mpf_spi_fpga_mgr",
> + .of_match_table = of_match_ptr(mpf_of_ids),
> + },
> +};
> +
> +module_spi_driver(mpf_driver);
> +
> +MODULE_DESCRIPTION("Microchip Polarfire SPI FPGA Manager");
> +MODULE_LICENSE("GPL");
> --
> 2.35.1
>
