lkml.org 
[lkml]   [2022]   [Feb]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v4] fpga: microchip-spi: add Microchip FPGA manager
On Thu, Feb 17, 2022 at 10:18:51PM +0300, Ivan Bornyakov wrote:
> Add support to the FPGA manager for programming Microchip Polarfire
> FPGAs over slave SPI interface.
>
> Signed-off-by: Ivan Bornyakov <i.bornyakov@metrotek.ru>
> ---
> Changelog:
> v1 -> v2: fix printk formating
> v2 -> v3:
> * replace "microsemi" with "microchip"
> * replace prefix "microsemi_fpga_" with "mpf_"
> * more sensible .compatible and .name strings
> * remove unused defines STATUS_SPI_VIOLATION and STATUS_SPI_ERROR
> v3 -> v4: fix unused variable warning
> Put 'mpf_of_ids' definition under conditional compilation, so it
> would not hang unused if CONFIG_OF is not enabled.
>
> drivers/fpga/Kconfig | 9 +
> drivers/fpga/Makefile | 1 +
> drivers/fpga/microchip-spi.c | 361 +++++++++++++++++++++++++++++++++++
> 3 files changed, 371 insertions(+)
> create mode 100644 drivers/fpga/microchip-spi.c
>
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index 26025dbab353..4240c641b100 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
> + select CRC_CCITT
> + help
> + FPGA manager driver support for Microchip Polarfire FPGAs
> + programming over slave SPI interface.
> +
> endif # FPGA
> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> index 4da5273948df..fcb389ca4873 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..5db25734a27a
> --- /dev/null
> +++ b/drivers/fpga/microchip-spi.c
> @@ -0,0 +1,361 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Microchip Polarfire FPGA programming over slave SPI interface.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/spi/spi.h>
> +#include <linux/of_device.h>
> +#include <linux/fpga/fpga-mgr.h>
> +#include <linux/delay.h>
> +#include <linux/crc-ccitt.h>

Please list them in alphabetical order.

> +
> +#define SPI_ISC_ENABLE 0x0B
> +#define SPI_ISC_DISABLE 0x0C
> +#define SPI_READ_STATUS 0x00
> +#define SPI_READ_DATA 0x01
> +#define SPI_FRAME_INIT 0xAE
> +#define SPI_FRAME 0xEE
> +#define SPI_PRG_MODE 0x01
> +#define SPI_RELEASE 0x23
> +
> +#define SPI_FRAME_SIZE 16
> +
> +#define HEADER_SIZE_OFFSET 24
> +#define DATA_SIZE_OFFSET 55
> +
> +#define LOOKUP_TABLE_RECORD_SIZE 9
> +#define LOOKUP_TABLE_BLOCK_ID_OFFSET 0
> +#define LOOKUP_TABLE_BLOCK_START_OFFSET 1
> +
> +#define COMPONENTS_SIZE_ID 5
> +#define BITSTREAM_ID 8
> +
> +#define BITS_PER_COMPONENT_SIZE 22
> +
> +#define STATUS_POLL_TIMEOUT_MS 1000
> +#define STATUS_BUSY BIT(0)
> +#define STATUS_READY BIT(1)

Maybe add some prefix for these vendor specific definitions, like
MFP_SPI_ISC_ENABLE.

> +
> +struct mpf_priv {
> + struct spi_device *spi;
> + bool program_mode;
> +};
> +
> +static enum fpga_mgr_states mpf_ops_state(struct fpga_manager *mgr)
> +{
> + struct mpf_priv *priv = mgr->priv;
> + struct spi_device *spi = priv->spi;
> + bool program_mode = priv->program_mode;
> + ssize_t status;
> +
> + status = spi_w8r8(spi, SPI_READ_STATUS);
> +
> + if (!program_mode && !status)
> + return FPGA_MGR_STATE_OPERATING;
> +
> + return FPGA_MGR_STATE_UNKNOWN;
> +}
> +
> +static int poll_status_not_busy(struct spi_device *spi, u8 mask)
> +{
> + ssize_t status, timeout = STATUS_POLL_TIMEOUT_MS;
> +
> + while (timeout--) {
> + status = spi_w8r8(spi, SPI_READ_STATUS);
> + if (status < 0)
> + return status;
> +
> + if (mask) {
> + if (!(status & STATUS_BUSY) && (status & mask))
> + return status;
> + } else {
> + if (!(status & STATUS_BUSY))
> + return status;
> + }

!(status & STATUS_BUSY) is always checked regardless of mask, so may
move the check out of the if...else statement.

> +
> + mdelay(1);

busy wait for 1ms is discouraged, maybe usleep_range(). See
Documentation/timers/timers-howto.rst

> + }

The actual timeout may be much longer than what is defined. To be more
accurate, you may use:

time_after(jiffies, timeout_jiffies)

> +
> + 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[] = { SPI_READ_DATA };
> + int ret;
> +
> + ret = mpf_spi_write(spi, txbuf, txbuf_size);
> + if (ret)
> + return ret;
> +
> + ret = poll_status_not_busy(spi, 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 isc_en_command[] = { SPI_ISC_ENABLE };
> + const u8 program_mode[] = { SPI_FRAME_INIT, SPI_PRG_MODE };

Better we follow the reverse xmas tree declaration, so reverse the 2
lines please.

> + struct mpf_priv *priv = mgr->priv;
> + struct spi_device *spi = priv->spi;
> + struct device *dev = &mgr->dev;
> + u32 isc_ret;
> + int ret;
> +
> + if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
> + dev_err(dev, "Partial reconfiguration is not supported\n");
> +

remove the blank line please

> + return -EOPNOTSUPP;
> + }
> +
> + 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 ? ret : isc_ret);

ret ? : isc_ret

> +

remove the blank line please

> + 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);
> +

the same

> + return ret;
> + }
> +
> + priv->program_mode = true;
> +
> + return 0;
> +}
> +
> +static ssize_t lookup_block_start(int id, const char *buf, size_t buf_size)
> +{
> + u8 header_size, blocks_num, block_id;
> + u32 block_start, i;
> +
> + header_size = *(buf + HEADER_SIZE_OFFSET);
> +
> + if (header_size > buf_size)
> + return -EFAULT;
> +
> + blocks_num = *(buf + header_size - 1);
> +
> + if (header_size + blocks_num * LOOKUP_TABLE_RECORD_SIZE > buf_size)
> + return -EFAULT;
> +
> + for (i = 0; i < blocks_num; i++) {
> + block_id = *(buf + header_size + LOOKUP_TABLE_RECORD_SIZE * i +
> + LOOKUP_TABLE_BLOCK_ID_OFFSET);
> +
> + if (block_id == id) {
> + memcpy(&block_start,
> + buf + header_size +
> + LOOKUP_TABLE_RECORD_SIZE * i +
> + LOOKUP_TABLE_BLOCK_START_OFFSET,
> + sizeof(block_start));

why a memcpy here, could we just read from the offset?

> +
> + return le32_to_cpu(block_start);
> + }
> + }
> +
> + return -EFAULT;
> +}
> +
> +static ssize_t parse_bitstream_size(const char *buf, size_t buf_size)
> +{
> + ssize_t bitstream_size = 0, components_size_start = 0,
> + component_size_byte_num, component_size_byte_off, i;
> + u16 components_num;
> + u32 component_size;
> +
> + memcpy(&components_num, buf + DATA_SIZE_OFFSET, sizeof(components_num));

the same, why a memcpy?

> + components_num = le16_to_cpu(components_num);
> +
> + components_size_start = lookup_block_start(COMPONENTS_SIZE_ID, buf,
> + buf_size);
> + if (components_size_start < 0)
> + return components_size_start;
> +
> + if (components_size_start +
> + DIV_ROUND_UP(components_num * BITS_PER_COMPONENT_SIZE,
> + BITS_PER_BYTE) > buf_size)
> + return -EFAULT;
> +
> + for (i = 0; i < components_num; i++) {
> + component_size_byte_num =
> + (i * BITS_PER_COMPONENT_SIZE) / BITS_PER_BYTE;
> + component_size_byte_off =
> + (i * BITS_PER_COMPONENT_SIZE) % BITS_PER_BYTE;
> +
> + memcpy(&component_size,
> + buf + components_size_start + component_size_byte_num,
> + sizeof(component_size));
> + component_size = le32_to_cpu(component_size);
> + component_size >>= component_size_byte_off;
> + component_size &= GENMASK(BITS_PER_COMPONENT_SIZE - 1, 0);
> +
> + bitstream_size += component_size;
> + }
> +
> + return bitstream_size;
> +}
> +
> +static int mpf_ops_write(struct fpga_manager *mgr, const char *buf, size_t count)
> +{
> + ssize_t bitstream_start = 0, bitstream_size;
> + struct mpf_priv *priv = mgr->priv;
> + struct spi_device *spi = priv->spi;
> + struct device *dev = &mgr->dev;
> + u8 tmp_buf[SPI_FRAME_SIZE + 1];
> + int ret, i;
> +
> + if (crc_ccitt(0, buf, count)) {
> + dev_err(dev, "CRC error\n");
> +
> + return -EINVAL;
> + }
> +
> + bitstream_start = lookup_block_start(BITSTREAM_ID, buf, count);
> + if (bitstream_start < 0) {
> + dev_err(dev, "Failed to find bitstream start %zd\n",
> + bitstream_start);
> +
> + return bitstream_start;
> + }
> +
> + bitstream_size = parse_bitstream_size(buf, count);
> + if (bitstream_size < 0) {
> + dev_err(dev, "Failed to parse bitstream size %zd\n",
> + bitstream_size);
> +
> + return bitstream_size;
> + }
> +
> + if (bitstream_start + bitstream_size * SPI_FRAME_SIZE > count) {
> + dev_err(dev,
> + "Bitstram outruns firmware. Bitstream start %zd, bitstream size %zd, firmware size %zu\n",

Bitstream

> + bitstream_start, bitstream_size * SPI_FRAME_SIZE, count);
> +
> + return -EFAULT;
> + }
> +

If I understand right, this function assumes the users provide the
entire image buffer. But it is possible the image buffer is from a
scatter list and the callback would be called several times.

Maybe the bitstream info at the head of the image could be parsed in
write_init(), and this requires the driver fill the
fpga_manager_ops.initial_header_size

> + for (i = 0; i < bitstream_size; i++) {
> + tmp_buf[0] = SPI_FRAME;
> + memcpy(tmp_buf + 1, buf + bitstream_start + i * SPI_FRAME_SIZE,
> + SPI_FRAME_SIZE);
> +
> + ret = mpf_spi_write(spi, tmp_buf, sizeof(tmp_buf));

Is it possible we use spi_sync_transfer to avoid memcpy the whole
bitstream?

> + if (ret) {
> + dev_err(dev,
> + "Failed to write bitstream frame number %d of %zd\n",
> + i, bitstream_size);
> +
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int mpf_ops_write_complete(struct fpga_manager *mgr,
> + struct fpga_image_info *info)

"CHECK: Alignment should match open parenthesis" from checkpatch.pl --strict

> +{
> + const u8 isc_dis_command[] = { SPI_ISC_DISABLE };
> + const u8 release_command[] = { SPI_RELEASE };
> + struct mpf_priv *priv = mgr->priv;
> + struct spi_device *spi = priv->spi;
> + struct device *dev = &mgr->dev;
> + int ret;
> +
> + 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;
> + }
> +
> + mdelay(1);

Same concern

> +
> + 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,
> + .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 mpf_priv *priv;
> + struct device *dev = &spi->dev;
> + struct fpga_manager *mgr;
> +
> + 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" },

From checkpatch.pl

"WARNING: DT compatible string "microchip,mpf-spi-fpga-mgr" appears un-documented -- check ./Documentation/devicetree/bindings/"

Thanks,
Yilun

> + {},
> +};
> +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");
> --
> 2.34.1
>

\
 
 \ /
  Last update: 2022-02-18 17:15    [W:0.143 / U:0.408 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site