Date:   Sat, 17 Sep 2022 01:10:28 +0800
From:   Xu Yilun <yilun.xu@...el.com>
To:     Ivan Bornyakov <i.bornyakov@...rotek.ru>
Cc:     mdf@...nel.org, hao.wu@...el.com, trix@...hat.com, dg@...ix.com,
        j.zink@...gutronix.de, robh+dt@...nel.org,
        krzysztof.kozlowski+dt@...aro.org, linux-fpga@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        kernel@...gutronix.de, system@...rotek.ru
Subject: Re: [PATCH v11 1/2] fpga: lattice-sysconfig-spi: add Lattice
 sysCONFIG FPGA manager

On 2022-09-13 at 16:07:13 +0300, Ivan Bornyakov wrote:
> Add support to the FPGA manager for programming Lattice ECP5 and MachXO2
> FPGAs over slave SPI sysCONFIG interface.
> 
> Signed-off-by: Ivan Bornyakov <i.bornyakov@...rotek.ru>
> ---
>  drivers/fpga/Kconfig         |   7 +
>  drivers/fpga/Makefile        |   3 +
>  drivers/fpga/sysconfig-spi.c | 210 ++++++++++++++
>  drivers/fpga/sysconfig.c     | 528 +++++++++++++++++++++++++++++++++++
>  drivers/fpga/sysconfig.h     |  62 ++++
>  5 files changed, 810 insertions(+)
>  create mode 100644 drivers/fpga/sysconfig-spi.c
>  create mode 100644 drivers/fpga/sysconfig.c
>  create mode 100644 drivers/fpga/sysconfig.h
> 
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index 6c416955da53..991d9d976dca 100644
> --- a/drivers/fpga/Kconfig
> +++ b/drivers/fpga/Kconfig
> @@ -263,4 +263,11 @@ config FPGA_MGR_MICROCHIP_SPI
>  	  programming over slave SPI interface with .dat formatted
>  	  bitstream image.
>  
> +config FPGA_MGR_LATTICE_SPI
> +	tristate "Lattice sysCONFIG SPI FPGA manager"
> +	depends on SPI
> +	help
> +	  FPGA manager driver support for Lattice FPGAs programming over slave
> +	  SPI sysCONFIG interface.
> +
>  endif # FPGA
> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> index 42ae8b58abce..70e5f58d0c10 100644
> --- a/drivers/fpga/Makefile
> +++ b/drivers/fpga/Makefile
> @@ -20,9 +20,12 @@ 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-$(CONFIG_FPGA_MGR_LATTICE_SPI)	+= lattice-sysconfig-spi.o
>  obj-$(CONFIG_ALTERA_PR_IP_CORE)		+= altera-pr-ip-core.o
>  obj-$(CONFIG_ALTERA_PR_IP_CORE_PLAT)	+= altera-pr-ip-core-plat.o
>  
> +lattice-sysconfig-spi-objs		:= sysconfig-spi.o sysconfig.o

What's your plan if sysconfig-i2c is to be added?

There are many examples in kernel actually, is it better like the
following:

  obj-$(CONFIG_FPGA_MGR_LATTICE_SYSCONFIG)	+= lattice-sysconfig.o
  obj-$(CONFIG_LATTICE_SYSCONFIG_SPI)		+= lattice-sysconfig-spi.o

> +
>  # FPGA Secure Update Drivers
>  obj-$(CONFIG_FPGA_M10_BMC_SEC_UPDATE)	+= intel-m10-bmc-sec-update.o
>  
> diff --git a/drivers/fpga/sysconfig-spi.c b/drivers/fpga/sysconfig-spi.c
> new file mode 100644
> index 000000000000..e2c71bc3b674
> --- /dev/null
> +++ b/drivers/fpga/sysconfig-spi.c
> @@ -0,0 +1,210 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Lattice FPGA programming over slave SPI sysCONFIG interface.
> + */
> +
> +#include <linux/of_device.h>
> +#include <linux/spi/spi.h>
> +
> +#include "sysconfig.h"
> +
> +struct sysconfig_spi_fpga_priv {
> +	const struct sysconfig_fpga_priv *fpga_priv;
> +	u32 max_speed_hz;
> +};
> +
> +static const struct sysconfig_spi_fpga_priv ecp5_spi_data = {
> +	.fpga_priv = &ecp5_data,
> +	.max_speed_hz = 60000000,
> +};
> +
> +static const struct sysconfig_spi_fpga_priv machxo2_spi_data = {
> +	.fpga_priv = &machxo2_data,
> +	.max_speed_hz = 66000000,
> +};
> +
> +static int sysconfig_spi_cmd_write(struct sysconfig_priv *priv,
> +				   const void *tx_buf, size_t tx_len)
> +{
> +	struct spi_device *spi = to_spi_device(priv->dev);
> +
> +	if (!spi)
> +		return -ENODEV;

Any reason to check it everytime? The driver should make sure it is
properly initialized on probe, is it?

> +
> +	return spi_write(spi, tx_buf, tx_len);
> +}
> +
> +static int sysconfig_spi_cmd_write_with_data(struct sysconfig_priv *priv,
> +					     const void *cmd, size_t cmd_len,
> +					     const void *data, size_t data_len)

I think the 2 write callbacks could be combined and named
sysconfig_spi_cmd_write()

> +{
> +	struct spi_device *spi = to_spi_device(priv->dev);
> +	struct spi_transfer xfers[2] = {
> +		{
> +			.tx_buf = cmd,
> +			.len = cmd_len,
> +		}, {
> +			.tx_buf = data,
> +			.len = data_len,
> +		},
> +	};
> +
> +	if (!spi)
> +		return -ENODEV;
> +
> +	return spi_sync_transfer(spi, xfers, 2);
> +}
> +
> +static int sysconfig_spi_cmd_write_then_read(struct sysconfig_priv *priv,
> +					     const void *tx_buf, size_t tx_len,
> +					     void *rx_buf, size_t rx_len)

Maybe just sysconfig_spi_cmd_read(), No matter write or read data, command word
should always be TXed first, so no need to say write here.

> +{
> +	struct spi_device *spi = to_spi_device(priv->dev);
> +
> +	if (!spi)
> +		return -ENODEV;
> +
> +	return spi_write_then_read(spi, tx_buf, tx_len, rx_buf, rx_len);
> +}
> +
> +static int sysconfig_spi_lsc_burst_init(struct sysconfig_priv *priv)

Is it better sysconfig_spi_bitstream_burst_init?

By the way, what is LSC & ISC?

> +{
> +	const u8 lsc_bitstream_burst[] = SYSCONFIG_LSC_BITSTREAM_BURST;
> +	struct spi_device *spi = to_spi_device(priv->dev);
> +	struct spi_transfer xfer = {
> +		.tx_buf = lsc_bitstream_burst,
> +		.len = sizeof(lsc_bitstream_burst),
> +		.cs_change = 1,

I'm not sure what's the effect to have cs_change on last transfer, is it to
last cs active to the next message?

> +	};
> +	struct spi_message msg;
> +	int ret;
> +
> +	if (!spi)
> +		return -ENODEV;
> +
> +	spi_message_init_with_transfers(&msg, &xfer, 1);
> +
> +	/*
> +	 * Lock SPI bus for exclusive usage until FPGA programming is done.
> +	 * SPI bus will be released in sysconfig_spi_lsc_burst_complete().
> +	 */
> +	spi_bus_lock(spi->controller);
> +
> +	ret = spi_sync_locked(spi, &msg);
> +	if (ret)
> +		spi_bus_unlock(spi->controller);
> +
> +	return ret;
> +}
> +
> +static int sysconfig_spi_bitstream_burst_write(struct sysconfig_priv *priv,
> +					       const char *buf, size_t count)

Why 'count', is 'len' better, to aligned with previous callbacks.

> +{
> +	struct spi_device *spi = to_spi_device(priv->dev);
> +	struct spi_transfer xfer = {
> +		.tx_buf = buf,
> +		.len = count,
> +		.cs_change = 1,
> +	};
> +	struct spi_message msg;
> +
> +	if (!spi)
> +		return -ENODEV;
> +
> +	spi_message_init_with_transfers(&msg, &xfer, 1);
> +
> +	return spi_sync_locked(spi, &msg);
> +}
> +
> +static int sysconfig_spi_lsc_burst_complete(struct sysconfig_priv *priv)

sysconfig_spi_bitstream_burst_complete?

> +{
> +	struct spi_device *spi = to_spi_device(priv->dev);
> +
> +	if (!spi)
> +		return -ENODEV;
> +
> +	/* Bitstream burst write is done, release SPI bus */
> +	spi_bus_unlock(spi->controller);
> +
> +	/* Toggle CS to finish bitstream write */
> +	return spi_write(spi, NULL, 0);
> +}
> +
> +static int sysconfig_spi_probe(struct spi_device *spi)
> +{
> +	const struct sysconfig_spi_fpga_priv *spi_fpga_priv;
> +	const struct spi_device_id *dev_id;
> +	struct device *dev = &spi->dev;
> +	struct sysconfig_priv *priv;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	spi_fpga_priv = of_device_get_match_data(dev);
> +	if (!spi_fpga_priv) {
> +		dev_id = spi_get_device_id(spi);
> +		if (!dev_id)
> +			return -ENODEV;
> +
> +		spi_fpga_priv = (const struct sysconfig_spi_fpga_priv *)dev_id->driver_data;
> +	}
> +
> +	if (!spi_fpga_priv)
> +		return -EINVAL;
> +
> +	if (spi->max_speed_hz > spi_fpga_priv->max_speed_hz) {
> +		dev_err(dev, "SPI speed %u is too high, maximum speed is %u\n",
> +			spi->max_speed_hz, spi_fpga_priv->max_speed_hz);
> +		return -EINVAL;
> +	}
> +
> +	priv->dev = dev;
> +	priv->fpga_priv = spi_fpga_priv->fpga_priv;
> +	priv->command_write = sysconfig_spi_cmd_write;
> +	priv->command_write_with_data = sysconfig_spi_cmd_write_with_data;
> +	priv->command_write_then_read = sysconfig_spi_cmd_write_then_read;
> +	priv->bitstream_burst_write_init = sysconfig_spi_lsc_burst_init;
> +	priv->bitstream_burst_write = sysconfig_spi_bitstream_burst_write;
> +	priv->bitstream_burst_write_complete = sysconfig_spi_lsc_burst_complete;
> +
> +	return sysconfig_probe(priv);
> +}
> +
> +static const struct spi_device_id sysconfig_spi_ids[] = {
> +	{
> +		.name = "sysconfig-ecp5",
> +		.driver_data = (kernel_ulong_t)&ecp5_spi_data,
> +	}, {
> +		.name = "sysconfig-machxo2",
> +		.driver_data = (kernel_ulong_t)&machxo2_spi_data,
> +	}, {},
> +};
> +MODULE_DEVICE_TABLE(spi, sysconfig_spi_ids);
> +
> +#if IS_ENABLED(CONFIG_OF)
> +static const struct of_device_id sysconfig_of_ids[] = {
> +	{
> +		.compatible = "lattice,sysconfig-ecp5",
> +		.data = &ecp5_spi_data,
> +	}, {
> +		.compatible = "lattice,sysconfig-machxo2",
> +		.data = &machxo2_spi_data,
> +	}, {},
> +};
> +MODULE_DEVICE_TABLE(of, sysconfig_of_ids);
> +#endif /* IS_ENABLED(CONFIG_OF) */
> +
> +static struct spi_driver lattice_sysconfig_driver = {
> +	.probe = sysconfig_spi_probe,
> +	.id_table = sysconfig_spi_ids,
> +	.driver = {
> +		.name = "lattice_sysconfig_spi_fpga_mgr",
> +		.of_match_table = of_match_ptr(sysconfig_of_ids),
> +	},
> +};
> +
> +module_spi_driver(lattice_sysconfig_driver);
> +
> +MODULE_DESCRIPTION("Lattice sysCONFIG Slave SPI FPGA Manager");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/fpga/sysconfig.c b/drivers/fpga/sysconfig.c
> new file mode 100644
> index 000000000000..af697203ed5d
> --- /dev/null
> +++ b/drivers/fpga/sysconfig.c
> @@ -0,0 +1,528 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Lattice FPGA sysCONFIG interface functions independent of port type.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/fpga/fpga-mgr.h>
> +#include <linux/gpio/consumer.h>
> +
> +#include "sysconfig.h"
> +
> +const struct sysconfig_fpga_priv ecp5_data = {
> +	.isc_enable_operand = 0x00,
> +	.burst_write = true,
> +	.internal_flash = false,

Sorry, we still have gaps here.
Machxo2 reprograming can be splitted to 2 steps, flash reprograming &
FPGA reconfiguration from flash, and now I think it is not a good idea
to include the 2 steps in an FPGA manager. Flash reprograming is actually
not the job for FPGA manager, it could be done by other existing
interfaces. And I also don't want to support it in this new driver. FPGA
reconfiguration from flash, as we discussed previously, could be a
FPGA manager feature, but could be considered later.

In another word, only to implement FPGA reconfiguration from bitstream
file, we don't even need to support machxo2 now.

For this sysconfig_fpga_priv, isc_enable_operand & internal_flash are
not need here, they are for flash reprograming actually. burst_write
is the only concern, any finding about whether page write works?

Thanks,
Yilun

> +};
> +
> +const struct sysconfig_fpga_priv machxo2_data = {
> +	.isc_enable_operand = 0x08,
> +	.burst_write = false,
> +	.internal_flash = true,
> +};
> +
> +static int sysconfig_cmd_write(struct sysconfig_priv *priv, const void *buf,
> +			       size_t buf_len)
> +{
> +	return priv->command_write(priv, buf, buf_len);
> +}
> +
> +static int sysconfig_cmd_write_with_data(struct sysconfig_priv *priv,
> +					 const void *cmd, size_t cmd_len,
> +					 const void *data, size_t data_len)
> +{
> +	return priv->command_write_with_data(priv, cmd, cmd_len, data, data_len);
> +}
> +
> +static int sysconfig_cmd_write_then_read(struct sysconfig_priv *priv,
> +					 const void *tx_buf, size_t tx_len,
> +					 void *rx_buf, size_t rx_len)
> +{
> +	return priv->command_write_then_read(priv, tx_buf, tx_len, rx_buf, rx_len);
> +}
> +
> +static int sysconfig_read_busy(struct sysconfig_priv *priv)
> +{
> +	const u8 lsc_check_busy[] = SYSCONFIG_LSC_CHECK_BUSY;
> +	u8 busy;
> +	int ret;
> +
> +	ret = sysconfig_cmd_write_then_read(priv, lsc_check_busy,
> +					    sizeof(lsc_check_busy),
> +					    &busy, sizeof(busy));
> +
> +	return ret ? : busy;
> +}
> +
> +static int sysconfig_poll_busy(struct sysconfig_priv *priv)
> +{
> +	size_t retries = SYSCONFIG_POLL_RETRIES;
> +	int ret;
> +
> +	while (retries--) {
> +		ret = sysconfig_read_busy(priv);
> +		if (ret <= 0)
> +			return ret;
> +
> +		usleep_range(SYSCONFIG_POLL_INTERVAL_US,
> +			     SYSCONFIG_POLL_INTERVAL_US * 2);
> +	}
> +
> +	return -EBUSY;
> +}
> +
> +static int sysconfig_read_status(struct sysconfig_priv *priv, u32 *status)
> +{
> +	const u8 lsc_read_status[] = SYSCONFIG_LSC_READ_STATUS;
> +	__be32 device_status;
> +	int ret;
> +
> +	ret = sysconfig_cmd_write_then_read(priv, lsc_read_status,
> +					    sizeof(lsc_read_status),
> +					    &device_status,
> +					    sizeof(device_status));
> +	if (ret)
> +		return ret;
> +
> +	*status = be32_to_cpu(device_status);
> +
> +	return 0;
> +}
> +
> +static int sysconfig_poll_status(struct sysconfig_priv *priv, u32 *status)
> +{
> +	int ret = sysconfig_poll_busy(priv);
> +
> +	if (ret)
> +		return ret;
> +
> +	return sysconfig_read_status(priv, status);
> +}
> +
> +static int sysconfig_poll_gpio(struct gpio_desc *gpio, bool is_active)
> +{
> +	size_t retries = SYSCONFIG_POLL_RETRIES;
> +	int value;
> +
> +	while (retries--) {
> +		value = gpiod_get_value(gpio);
> +		if (value < 0)
> +			return value;
> +
> +		if ((is_active && value) || (!is_active && !value))
> +			return 0;
> +	}
> +
> +	return -ETIMEDOUT;
> +}
> +
> +static int sysconfig_gpio_refresh(struct sysconfig_priv *priv)
> +{
> +	struct gpio_desc *program = priv->program;
> +	struct gpio_desc *init = priv->init;
> +	struct gpio_desc *done = priv->done;
> +	int ret;
> +
> +	/* Enter init mode */
> +	gpiod_set_value(program, 1);
> +
> +	ret = sysconfig_poll_gpio(init, true);
> +	if (!ret)
> +		ret = sysconfig_poll_gpio(done, false);
> +
> +	if (ret)
> +		return ret;
> +
> +	/* Enter program mode */
> +	gpiod_set_value(program, 0);
> +
> +	return sysconfig_poll_gpio(init, false);
> +}
> +
> +static int sysconfig_lsc_refresh(struct sysconfig_priv *priv)
> +{
> +	static const u8 lsc_refresh[] = SYSCONFIG_LSC_REFRESH;
> +	int ret;
> +
> +	ret = sysconfig_cmd_write(priv, lsc_refresh, sizeof(lsc_refresh));
> +	if (ret)
> +		return ret;
> +
> +	usleep_range(4000, 8000);
> +
> +	return 0;
> +}
> +
> +static int sysconfig_refresh(struct sysconfig_priv *priv)
> +{
> +	struct gpio_desc *program = priv->program;
> +	struct gpio_desc *init = priv->init;
> +	struct gpio_desc *done = priv->done;
> +
> +	if (program && init && done)
> +		return sysconfig_gpio_refresh(priv);
> +
> +	return sysconfig_lsc_refresh(priv);
> +}
> +
> +static int sysconfig_isc_enable(struct sysconfig_priv *priv)
> +{
> +	const struct sysconfig_fpga_priv *fpga_priv = priv->fpga_priv;
> +	u8 isc_enable[] = SYSCONFIG_ISC_ENABLE;
> +	u32 status;
> +	int ret;
> +
> +	isc_enable[1] = fpga_priv->isc_enable_operand;
> +
> +	ret = sysconfig_cmd_write(priv, isc_enable, sizeof(isc_enable));
> +	if (ret)
> +		return ret;
> +
> +	ret = sysconfig_poll_status(priv, &status);
> +	if (ret || (status & SYSCONFIG_STATUS_FAIL))
> +		return ret ? : -EFAULT;
> +
> +	return 0;
> +}
> +
> +static int sysconfig_isc_erase(struct sysconfig_priv *priv)
> +{
> +	const struct sysconfig_fpga_priv *fpga_priv = priv->fpga_priv;
> +	u8 isc_erase[] = SYSCONFIG_ISC_ERASE;
> +	u32 status;
> +	int ret;
> +
> +	isc_erase[1] = SYSCONFIG_ISC_ERASE_SRAM;
> +
> +	if (fpga_priv->internal_flash)
> +		isc_erase[1] |= SYSCONFIG_ISC_ERASE_FLASH;
> +
> +	ret = sysconfig_cmd_write(priv, isc_erase, sizeof(isc_erase));
> +	if (ret)
> +		return ret;
> +
> +	ret = sysconfig_poll_status(priv, &status);
> +	if (ret || (status & SYSCONFIG_STATUS_FAIL))
> +		return ret ? : -EFAULT;
> +
> +	return 0;
> +}
> +
> +static int sysconfig_isc_init(struct sysconfig_priv *priv)
> +{
> +	int ret = sysconfig_isc_enable(priv);
> +
> +	if (ret)
> +		return ret;
> +
> +	return sysconfig_isc_erase(priv);
> +}
> +
> +static int sysconfig_lsc_init_addr(struct sysconfig_priv *priv)
> +{
> +	const u8 lsc_init_addr[] = SYSCONFIG_LSC_INIT_ADDR;
> +
> +	return sysconfig_cmd_write(priv, lsc_init_addr, sizeof(lsc_init_addr));
> +}
> +
> +static int sysconfig_burst_write_init(struct sysconfig_priv *priv)
> +{
> +	if (priv->bitstream_burst_write_init)
> +		return priv->bitstream_burst_write_init(priv);
> +
> +	return 0;
> +}
> +
> +static int sysconfig_burst_write_complete(struct sysconfig_priv *priv)
> +{
> +	if (priv->bitstream_burst_write_complete)
> +		return priv->bitstream_burst_write_complete(priv);
> +
> +	return 0;
> +}
> +
> +static int sysconfig_bitstream_burst_write(struct sysconfig_priv *priv,
> +					   const char *buf, size_t count)
> +{
> +	int ret;
> +
> +	if (priv->bitstream_burst_write)
> +		ret = priv->bitstream_burst_write(priv, buf, count);
> +	else
> +		ret = -EOPNOTSUPP;
> +
> +	if (ret)
> +		sysconfig_burst_write_complete(priv);
> +
> +	return ret;
> +}
> +
> +static int sysconfig_bitstream_paged_write(struct sysconfig_priv *priv,
> +					   const char *buf, size_t count)
> +{
> +	const u8 lsc_progincr[] = SYSCONFIG_LSC_PROG_INCR_NV;
> +	size_t i;
> +	int ret;
> +
> +	if (count % SYSCONFIG_PAGE_SIZE)
> +		return -EINVAL;
> +
> +	for (i = 0; i < count; i += SYSCONFIG_PAGE_SIZE) {
> +		ret = sysconfig_cmd_write_with_data(priv, lsc_progincr,
> +						    sizeof(lsc_progincr),
> +						    buf + i, SYSCONFIG_PAGE_SIZE);
> +		if (!ret)
> +			ret = sysconfig_poll_busy(priv);
> +
> +		if (ret)
> +			break;
> +	}
> +
> +	return ret;
> +}
> +
> +static int sysconfig_isc_prog_done(struct sysconfig_priv *priv)
> +{
> +	const u8 isc_prog_done[] = SYSCONFIG_ISC_PROGRAM_DONE;
> +	u32 status;
> +	int ret;
> +
> +	ret = sysconfig_cmd_write(priv, isc_prog_done, sizeof(isc_prog_done));
> +	if (ret)
> +		return ret;
> +
> +	ret = sysconfig_poll_status(priv, &status);
> +	if (ret)
> +		return ret;
> +
> +	if (status & SYSCONFIG_STATUS_DONE)
> +		return 0;
> +
> +	return -EFAULT;
> +}
> +
> +static int sysconfig_isc_disable(struct sysconfig_priv *priv)
> +{
> +	const u8 isc_disable[] = SYSCONFIG_ISC_DISABLE;
> +
> +	return sysconfig_cmd_write(priv, isc_disable, sizeof(isc_disable));
> +}
> +
> +static void sysconfig_cleanup(struct sysconfig_priv *priv)
> +{
> +	sysconfig_isc_erase(priv);
> +	sysconfig_refresh(priv);
> +}
> +
> +static int sysconfig_isc_finish(struct sysconfig_priv *priv)
> +{
> +	const struct sysconfig_fpga_priv *fpga_priv = priv->fpga_priv;
> +	int ret, retries = SYSCONFIG_REFRESH_RETRIES;
> +	struct gpio_desc *done_gpio = priv->done;
> +	u32 status;
> +
> +	if (done_gpio) {
> +		ret = sysconfig_isc_disable(priv);
> +		if (ret)
> +			return ret;
> +
> +		return sysconfig_poll_gpio(done_gpio, true);
> +	}
> +
> +	while (retries--) {
> +		ret = sysconfig_poll_status(priv, &status);
> +		if (ret)
> +			break;
> +
> +		if ((status & SYSCONFIG_STATUS_DONE) &&
> +		    !(status & SYSCONFIG_STATUS_BUSY) &&
> +		    !(status & SYSCONFIG_STATUS_ERR)) {
> +			return sysconfig_isc_disable(priv);
> +		}
> +
> +		if (fpga_priv->internal_flash) {
> +			ret = sysconfig_refresh(priv);
> +			if (ret)
> +				break;
> +		}
> +	}
> +
> +	return -EFAULT;
> +}
> +
> +static enum fpga_mgr_states sysconfig_ops_state(struct fpga_manager *mgr)
> +{
> +	struct sysconfig_priv *priv = mgr->priv;
> +	struct gpio_desc *done = priv->done;
> +	u32 status;
> +	int ret;
> +
> +	if (done && (gpiod_get_value(done) > 0))
> +		return FPGA_MGR_STATE_OPERATING;
> +
> +	ret = sysconfig_read_status(priv, &status);
> +	if (!ret && (status & SYSCONFIG_STATUS_DONE))
> +		return FPGA_MGR_STATE_OPERATING;
> +
> +	return FPGA_MGR_STATE_UNKNOWN;
> +}
> +
> +static int sysconfig_ops_write_init(struct fpga_manager *mgr,
> +				    struct fpga_image_info *info,
> +				    const char *buf, size_t count)
> +{
> +	const struct sysconfig_fpga_priv *fpga_priv;
> +	struct sysconfig_priv *priv;
> +	struct device *dev;
> +	int ret;
> +
> +	dev = &mgr->dev;
> +	priv = mgr->priv;
> +	fpga_priv = priv->fpga_priv;
> +
> +	if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
> +		dev_err(dev, "Partial reconfiguration is not supported\n");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	if (!fpga_priv->internal_flash) {
> +		/* Write directly to SRAM */
> +		ret = sysconfig_refresh(priv);
> +		if (ret) {
> +			dev_err(dev, "Failed to go to program mode\n");
> +			return ret;
> +		}
> +	}
> +
> +	/* Enter ISC mode */
> +	ret = sysconfig_isc_init(priv);
> +	if (ret) {
> +		dev_err(dev, "Failed to go to ISC mode\n");
> +		return ret;
> +	}
> +
> +	/* Initialize the Address Shift Register */
> +	ret = sysconfig_lsc_init_addr(priv);
> +	if (ret) {
> +		dev_err(dev,
> +			"Failed to initialize the Address Shift Register\n");
> +		return ret;
> +	}
> +
> +	if (fpga_priv->burst_write) {
> +		/* Prepare for bitstream burst write */
> +		ret = sysconfig_burst_write_init(priv);
> +		if (ret)
> +			dev_err(dev,
> +				"Failed to prepare for bitstream burst write\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int sysconfig_ops_write(struct fpga_manager *mgr, const char *buf,
> +			       size_t count)
> +{
> +	const struct sysconfig_fpga_priv *fpga_priv;
> +	struct sysconfig_priv *priv;
> +
> +	priv = mgr->priv;
> +	fpga_priv = priv->fpga_priv;
> +
> +	if (fpga_priv->burst_write)
> +		return sysconfig_bitstream_burst_write(priv, buf, count);
> +
> +	return sysconfig_bitstream_paged_write(priv, buf, count);
> +}
> +
> +static int sysconfig_ops_write_complete(struct fpga_manager *mgr,
> +					struct fpga_image_info *info)
> +{
> +	const struct sysconfig_fpga_priv *fpga_priv;
> +	struct sysconfig_priv *priv;
> +	struct device *dev;
> +	int ret;
> +
> +	dev = &mgr->dev;
> +	priv = mgr->priv;
> +	fpga_priv = priv->fpga_priv;
> +
> +	if (fpga_priv->burst_write) {
> +		ret = sysconfig_burst_write_complete(priv);
> +		if (!ret)
> +			ret = sysconfig_poll_busy(priv);
> +
> +		if (ret) {
> +			dev_err(dev,
> +				"Error while waiting bitstream write to finish\n");
> +			goto fail;
> +		}
> +	}
> +
> +	if (fpga_priv->internal_flash) {
> +		ret = sysconfig_isc_prog_done(priv);
> +		if (!ret)
> +			ret = sysconfig_refresh(priv);
> +
> +		if (ret) {
> +			dev_err(dev, "Failed to enable Self-Download Mode\n");
> +			goto fail;
> +		}
> +	}
> +
> +	ret = sysconfig_isc_finish(priv);
> +
> +fail:
> +	if (ret)
> +		sysconfig_cleanup(priv);
> +
> +	return ret;
> +}
> +
> +static const struct fpga_manager_ops sysconfig_fpga_mgr_ops = {
> +	.state = sysconfig_ops_state,
> +	.write_init = sysconfig_ops_write_init,
> +	.write = sysconfig_ops_write,
> +	.write_complete = sysconfig_ops_write_complete,
> +};
> +
> +int sysconfig_probe(struct sysconfig_priv *priv)
> +{
> +	struct gpio_desc *program, *init, *done;
> +	struct device *dev = priv->dev;
> +	struct fpga_manager *mgr;
> +	int ret;
> +
> +	if (!dev)
> +		return -ENODEV;
> +
> +	program = devm_gpiod_get_optional(dev, "program", GPIOD_OUT_LOW);
> +	if (IS_ERR(program)) {
> +		ret = PTR_ERR(program);
> +		dev_err(dev, "Failed to get PROGRAM GPIO: %d\n", ret);
> +		return ret;
> +	}
> +
> +	init = devm_gpiod_get_optional(dev, "init", GPIOD_IN);
> +	if (IS_ERR(init)) {
> +		ret = PTR_ERR(init);
> +		dev_err(dev, "Failed to get INIT GPIO: %d\n", ret);
> +		return ret;
> +	}
> +
> +	done = devm_gpiod_get_optional(dev, "done", GPIOD_IN);
> +	if (IS_ERR(done)) {
> +		ret = PTR_ERR(done);
> +		dev_err(dev, "Failed to get DONE GPIO: %d\n", ret);
> +		return ret;
> +	}
> +
> +	priv->program = program;
> +	priv->init = init;
> +	priv->done = done;
> +
> +	mgr = devm_fpga_mgr_register(dev, "Lattice sysCONFIG FPGA Manager",
> +				     &sysconfig_fpga_mgr_ops, priv);
> +
> +	return PTR_ERR_OR_ZERO(mgr);
> +}
> diff --git a/drivers/fpga/sysconfig.h b/drivers/fpga/sysconfig.h
> new file mode 100644
> index 000000000000..decb0958ee51
> --- /dev/null
> +++ b/drivers/fpga/sysconfig.h
> @@ -0,0 +1,62 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef	__LATTICE_SYSCONFIG_H
> +#define	__LATTICE_SYSCONFIG_H
> +
> +#define	SYSCONFIG_ISC_ENABLE		{0xC6, 0x00, 0x00, 0x00}
> +#define	SYSCONFIG_ISC_DISABLE		{0x26, 0x00, 0x00, 0x00}
> +#define	SYSCONFIG_ISC_ERASE		{0x0E, 0x00, 0x00, 0x00}
> +#define	SYSCONFIG_ISC_PROGRAM_DONE	{0x5E, 0x00, 0x00, 0x00}
> +#define	SYSCONFIG_LSC_READ_STATUS	{0x3C, 0x00, 0x00, 0x00}
> +#define	SYSCONFIG_LSC_CHECK_BUSY	{0xF0, 0x00, 0x00, 0x00}
> +#define	SYSCONFIG_LSC_REFRESH		{0x79, 0x00, 0x00, 0x00}
> +#define	SYSCONFIG_LSC_INIT_ADDR		{0x46, 0x00, 0x00, 0x00}
> +#define	SYSCONFIG_LSC_BITSTREAM_BURST	{0x7a, 0x00, 0x00, 0x00}
> +#define	SYSCONFIG_LSC_PROG_INCR_NV	{0x70, 0x00, 0x00, 0x01}
> +
> +#define	SYSCONFIG_ISC_ERASE_SRAM	BIT(0)
> +#define	SYSCONFIG_ISC_ERASE_FLASH	BIT(2)
> +
> +#define	SYSCONFIG_STATUS_DONE		BIT(8)
> +#define	SYSCONFIG_STATUS_BUSY		BIT(12)
> +#define	SYSCONFIG_STATUS_FAIL		BIT(13)
> +#define	SYSCONFIG_STATUS_ERR		(BIT(23) | BIT(24) | BIT(25))
> +
> +#define	SYSCONFIG_REFRESH_RETRIES	16
> +#define	SYSCONFIG_POLL_RETRIES		1000000
> +#define	SYSCONFIG_POLL_INTERVAL_US	30
> +
> +#define	SYSCONFIG_PAGE_SIZE		16
> +
> +struct sysconfig_fpga_priv {
> +	u8 isc_enable_operand;
> +	bool burst_write;
> +	bool internal_flash;
> +};
> +
> +extern const struct sysconfig_fpga_priv ecp5_data;
> +extern const struct sysconfig_fpga_priv machxo2_data;
> +
> +struct sysconfig_priv {
> +	const struct sysconfig_fpga_priv *fpga_priv;
> +	struct gpio_desc *program;
> +	struct gpio_desc *init;
> +	struct gpio_desc *done;
> +	struct device *dev;
> +	int (*command_write)(struct sysconfig_priv *priv,
> +			     const void *tx_buf, size_t tx_len);
> +	int (*command_write_with_data)(struct sysconfig_priv *priv,
> +				       const void *cmd_buf, size_t cmd_len,
> +				       const void *data_buf, size_t data_len);
> +	int (*command_write_then_read)(struct sysconfig_priv *priv,
> +				       const void *tx_buf, size_t tx_len,
> +				       void *rx_buf, size_t rx_len);
> +	int (*bitstream_burst_write_init)(struct sysconfig_priv *priv);
> +	int (*bitstream_burst_write)(struct sysconfig_priv *priv,
> +				     const char *tx_buf, size_t tx_len);
> +	int (*bitstream_burst_write_complete)(struct sysconfig_priv *priv);
> +};
> +
> +int sysconfig_probe(struct sysconfig_priv *priv);
> +
> +#endif /* __LATTICE_SYSCONFIG_H */
> -- 
> 2.37.3
> 
> 

Powered by blists - more mailing lists