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Date:   Tue, 16 Aug 2022 14:09:18 +0800
From:   Xu Yilun <yilun.xu@intel.com>
To:     Ivan Bornyakov <i.bornyakov@metrotek.ru>
Cc:     mdf@kernel.org, hao.wu@intel.com, trix@redhat.com, dg@emlix.com,
        robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
        linux-fpga@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, system@metrotek.ru,
        yilun.xu@intel.com
Subject: Re: [PATCH v6 1/2] fpga: ecp5-spi: add Lattice ECP5 FPGA manager
Message-ID: <Yvs0jieXsyzhn8q9@yilunxu-OptiPlex-7050>
References: <20220815132157.8083-1-i.bornyakov@metrotek.ru>
 <20220815132157.8083-2-i.bornyakov@metrotek.ru>
 <Yvr6SY5WGXlYiLig@yilunxu-OptiPlex-7050>
 <20220816045841.irhr5vigemdqknaw@x260>
MIME-Version: 1.0
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In-Reply-To: <20220816045841.irhr5vigemdqknaw@x260>
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On 2022-08-16 at 07:58:41 +0300, Ivan Bornyakov wrote:
> On Tue, Aug 16, 2022 at 10:00:41AM +0800, Xu Yilun wrote:
> > On 2022-08-15 at 16:21:56 +0300, Ivan Bornyakov wrote:
> > > Add support to the FPGA manager for programming Lattice ECP5 FPGA over
> > > slave SPI interface with .bit formatted uncompressed bitstream image.
> > 
> > Not sure if something is missed.
> > 
> > https://lore.kernel.org/all/20220729145757.GA2601292@yilunxu-OptiPlex-7050/
> > 
> > I was considering if a generic driver for lattice slave SPI sysCONFIG
> > interface could be introduced. From machxo2 & ecp5 Programming Usage
> > Guide, or others in this series, they basically use the same reconfigure
> > interface & protocol.
> > 
> > Thanks,
> > Yilun
> > 
> 
> I only have HW with ECP5, can't vouch for the rest.

I understand your concern, but having separate drivers for the same IP on
different boards makes the maintaining harder.

We don't have to make everything fine, but start with machxo2 and ecp5
first. If the change affects machxo2, other people may help.

Thanks,
Yilun

> 
> > > 
> > > Signed-off-by: Ivan Bornyakov <i.bornyakov@metrotek.ru>
> > > ---
> > >  drivers/fpga/Kconfig    |   7 +
> > >  drivers/fpga/Makefile   |   1 +
> > >  drivers/fpga/ecp5-spi.c | 311 ++++++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 319 insertions(+)
> > >  create mode 100644 drivers/fpga/ecp5-spi.c
> > > 
> > > diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> > > index 6c416955da53..920277a08ed9 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_ECP5_SPI
> > > +	tristate "Lattice ECP5 SPI FPGA manager"
> > > +	depends on SPI
> > > +	help
> > > +	  FPGA manager driver support for Lattice ECP5 programming over slave
> > > +	  SPI interface with .bit formatted uncompressed bitstream image.
> > > +
> > >  endif # FPGA
> > > diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> > > index 42ae8b58abce..17c7a3c4b385 100644
> > > --- a/drivers/fpga/Makefile
> > > +++ b/drivers/fpga/Makefile
> > > @@ -20,6 +20,7 @@ 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-$(CONFIG_FPGA_MGR_ECP5_SPI)		+= ecp5-spi.o
> > >  obj-$(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/ecp5-spi.c b/drivers/fpga/ecp5-spi.c
> > > new file mode 100644
> > > index 000000000000..aa0dd10823a3
> > > --- /dev/null
> > > +++ b/drivers/fpga/ecp5-spi.c
> > > @@ -0,0 +1,311 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * Lattice ECP5 FPGA programming over slave SPI interface.
> > > + */
> > > +
> > > +#include <linux/delay.h>
> > > +#include <linux/fpga/fpga-mgr.h>
> > > +#include <linux/spi/spi.h>
> > > +
> > > +#define	ECP5_SPI_MAX_SPEED_HZ		60000000
> > > +
> > > +#define	ECP5_SPI_ISC_ENABLE		{0xC6, 0x00, 0x00, 0x00}
> > > +#define	ECP5_SPI_ISC_DISABLE		{0x26, 0x00, 0x00, 0x00}
> > > +#define	ECP5_SPI_ISC_ERASE		{0x0E, 0x01, 0x00, 0x00}
> > > +#define	ECP5_SPI_LSC_INIT_ADDR		{0x46, 0x00, 0x00, 0x00}
> > > +#define	ECP5_SPI_LSC_BITSTREAM_BURST	{0x7a, 0x00, 0x00, 0x00}
> > > +#define	ECP5_SPI_LSC_CHECK_BUSY		{0xF0, 0x00, 0x00, 0x00}
> > > +
> > > +#define ECP5_POLL_RETRIES		100000
> > > +
> > > +struct ecp5_priv {
> > > +	struct gpio_desc *program;
> > > +	struct gpio_desc *init;
> > > +	struct gpio_desc *done;
> > > +	struct spi_device *spi;
> > > +};
> > > +
> > > +static enum fpga_mgr_states ecp5_ops_state(struct fpga_manager *mgr)
> > > +{
> > > +	struct ecp5_priv *priv = mgr->priv;
> > > +
> > > +	return gpiod_get_value(priv->done) ? FPGA_MGR_STATE_OPERATING :
> > > +					     FPGA_MGR_STATE_UNKNOWN;
> > > +}
> > > +
> > > +static int ecp5_poll_busy(struct spi_device *spi)
> > > +{
> > > +	const u8 lsc_check_busy[] = ECP5_SPI_LSC_CHECK_BUSY;
> > > +	int ret, retries = ECP5_POLL_RETRIES;
> > > +	struct spi_transfer xfers[2] = { 0 };
> > > +	struct spi_message msg;
> > > +	u8 busy;
> > > +
> > > +	xfers[0].tx_buf = lsc_check_busy;
> > > +	xfers[0].len = sizeof(lsc_check_busy);
> > > +	xfers[1].rx_buf = &busy;
> > > +	xfers[1].len = sizeof(busy);
> > > +
> > > +	while (retries--) {
> > > +		spi_message_init_with_transfers(&msg, xfers, ARRAY_SIZE(xfers));
> > > +		ret = spi_sync_locked(spi, &msg);
> > > +		if (ret)
> > > +			return ret;
> > > +
> > > +		if (!busy)
> > > +			return 0;
> > > +
> > > +		usleep_range(50, 100);
> > > +	}
> > > +
> > > +	return -EBUSY;
> > > +}
> > > +
> > > +static int ecp5_poll_gpio(struct gpio_desc *gpio, bool is_active)
> > > +{
> > > +	int value, retries = ECP5_POLL_RETRIES;
> > > +
> > > +	while (retries--) {
> > > +		value = gpiod_get_value(gpio);
> > > +		if (value < 0)
> > > +			return value;
> > > +
> > > +		if ((!is_active && !value) || (is_active && value))
> > > +			return 0;
> > > +
> > > +		ndelay(10);
> > > +	}
> > > +
> > > +	return -EFAULT;
> > > +}
> > > +
> > > +static int ecp5_ops_write_init(struct fpga_manager *mgr,
> > > +			       struct fpga_image_info *info,
> > > +			       const char *buf, size_t count)
> > > +{
> > > +	const u8 lsc_bitstream_burst[] = ECP5_SPI_LSC_BITSTREAM_BURST;
> > > +	const u8 lsc_init_addr[] = ECP5_SPI_LSC_INIT_ADDR;
> > > +	const u8 isc_enable[] = ECP5_SPI_ISC_ENABLE;
> > > +	const u8 isc_erase[] = ECP5_SPI_ISC_ERASE;
> > > +	struct ecp5_priv *priv = mgr->priv;
> > > +	struct spi_device *spi = priv->spi;
> > > +	struct device *dev = &mgr->dev;
> > > +	struct spi_transfer isc_xfers[] = {
> > > +		{
> > > +			.tx_buf = isc_enable,
> > > +			.len = sizeof(isc_enable),
> > > +			.cs_change = 1,
> > > +		}, {
> > > +			.tx_buf = isc_erase,
> > > +			.len = sizeof(isc_erase),
> > > +		},
> > > +	};
> > > +	struct spi_transfer lsc_xfers[] = {
> > > +		{
> > > +			.tx_buf = lsc_init_addr,
> > > +			.len = sizeof(lsc_init_addr),
> > > +			.cs_change = 1,
> > > +		}, {
> > > +			.tx_buf = lsc_bitstream_burst,
> > > +			.len = sizeof(lsc_bitstream_burst),
> > > +			.cs_change = 1,
> > > +		},
> > > +	};
> > > +	struct spi_message msg;
> > > +	int ret;
> > > +
> > > +	if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
> > > +		dev_err(dev, "Partial reconfiguration is not supported\n");
> > > +		return -EOPNOTSUPP;
> > > +	}
> > > +
> > > +	/* Enter init mode */
> > > +	gpiod_set_value(priv->program, 1);
> > > +
> > > +	ret = ecp5_poll_gpio(priv->init, true);
> > > +	if (!ret)
> > > +		ret = ecp5_poll_gpio(priv->done, false);
> > > +
> > > +	if (ret) {
> > > +		dev_err(dev, "Failed to go to initialization mode\n");
> > > +		return ret;
> > > +	}
> > > +
> > > +	/* Enter program mode */
> > > +	gpiod_set_value(priv->program, 0);
> > > +
> > > +	ret = ecp5_poll_gpio(priv->init, false);
> > > +	if (ret) {
> > > +		dev_err(dev, "Failed to go to program mode\n");
> > > +		return ret;
> > > +	}
> > > +
> > > +	/*
> > > +	 * Lock SPI bus for exclusive usage until FPGA programming is done.
> > > +	 * SPI bus will be released in ecp5_ops_write_complete() or on error.
> > > +	 */
> > > +	spi_bus_lock(spi->controller);
> > > +
> > > +	/* Enter ISC mode */
> > > +	spi_message_init_with_transfers(&msg, isc_xfers, ARRAY_SIZE(isc_xfers));
> > > +	ret = spi_sync_locked(spi, &msg);
> > > +	if (!ret)
> > > +		ret = ecp5_poll_busy(spi);
> > > +
> > > +	if (ret) {
> > > +		dev_err(dev, "Failed to go to ISC mode\n");
> > > +		goto out;
> > > +	}
> > > +
> > > +	/* Prepare for bitstream burst write */
> > > +	spi_message_init_with_transfers(&msg, lsc_xfers, ARRAY_SIZE(lsc_xfers));
> > > +	ret = spi_sync_locked(spi, &msg);
> > > +	if (ret)
> > > +		dev_err(dev, "Failed to prepare for bitstream burst write\n");
> > > +
> > > +out:
> > > +	if (ret)
> > > +		spi_bus_unlock(spi->controller);
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +static int ecp5_ops_write(struct fpga_manager *mgr, const char *buf, size_t count)
> > > +{
> > > +	struct ecp5_priv *priv = mgr->priv;
> > > +	struct spi_device *spi = priv->spi;
> > > +	struct spi_transfer xfer = {
> > > +		.tx_buf = buf,
> > > +		.len = count,
> > > +		.cs_change = 1,
> > > +	};
> > > +	struct spi_message msg;
> > > +	int ret;
> > > +
> > > +	spi_message_init_with_transfers(&msg, &xfer, 1);
> > > +	ret = spi_sync_locked(spi, &msg);
> > > +	if (ret)
> > > +		spi_bus_unlock(spi->controller);
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +static int ecp5_ops_write_complete(struct fpga_manager *mgr,
> > > +				   struct fpga_image_info *info)
> > > +{
> > > +	const u8 isc_disable[] = ECP5_SPI_ISC_DISABLE;
> > > +	struct ecp5_priv *priv = mgr->priv;
> > > +	struct spi_device *spi = priv->spi;
> > > +	struct spi_transfer xfer = { 0 };
> > > +	struct device *dev = &mgr->dev;
> > > +	struct spi_message msg;
> > > +	int ret;
> > > +
> > > +	/* Toggle CS and wait for bitstream write to finish */
> > > +	spi_message_init_with_transfers(&msg, &xfer, 1);
> > > +	ret = spi_sync_locked(spi, &msg);
> > > +	if (!ret)
> > > +		ret = ecp5_poll_busy(spi);
> > > +
> > > +	if (ret) {
> > > +		dev_err(dev, "Error while waiting bitstream write to finish\n");
> > > +		goto out;
> > > +	}
> > > +
> > > +	/* Exit ISC mode */
> > > +	xfer.tx_buf = isc_disable;
> > > +	xfer.len = sizeof(isc_disable);
> > > +	spi_message_init_with_transfers(&msg, &xfer, 1);
> > > +	ret = spi_sync_locked(spi, &msg);
> > > +	if (!ret)
> > > +		ret = ecp5_poll_gpio(priv->done, true);
> > > +
> > > +	if (ret)
> > > +		dev_err(dev, "Failed to finish ISC\n");
> > > +
> > > +out:
> > > +	spi_bus_unlock(spi->controller);
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +static const struct fpga_manager_ops ecp5_fpga_ops = {
> > > +	.state = ecp5_ops_state,
> > > +	.write_init = ecp5_ops_write_init,
> > > +	.write = ecp5_ops_write,
> > > +	.write_complete = ecp5_ops_write_complete,
> > > +};
> > > +
> > > +static int ecp5_probe(struct spi_device *spi)
> > > +{
> > > +	struct device *dev = &spi->dev;
> > > +	struct fpga_manager *mgr;
> > > +	struct ecp5_priv *priv;
> > > +	int ret;
> > > +
> > > +	if (spi->max_speed_hz > ECP5_SPI_MAX_SPEED_HZ) {
> > > +		dev_err(dev, "SPI speed %u is too high, maximum speed is %u\n",
> > > +			spi->max_speed_hz, ECP5_SPI_MAX_SPEED_HZ);
> > > +		return -EINVAL;
> > > +	}
> > > +
> > > +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> > > +	if (!priv)
> > > +		return -ENOMEM;
> > > +
> > > +	priv->spi = spi;
> > > +
> > > +	priv->done = devm_gpiod_get(dev, "done", GPIOD_IN);
> > > +	if (IS_ERR(priv->done)) {
> > > +		ret = PTR_ERR(priv->done);
> > > +		dev_err(dev, "Failed to get DONE GPIO: %d\n", ret);
> > > +		return ret;
> > > +	}
> > > +
> > > +	priv->init = devm_gpiod_get(dev, "init", GPIOD_IN);
> > > +	if (IS_ERR(priv->init)) {
> > > +		ret = PTR_ERR(priv->init);
> > > +		dev_err(dev, "Failed to get INIT GPIO: %d\n", ret);
> > > +		return ret;
> > > +	}
> > > +
> > > +	priv->program = devm_gpiod_get(dev, "program", GPIOD_OUT_LOW);
> > > +	if (IS_ERR(priv->program)) {
> > > +		ret = PTR_ERR(priv->program);
> > > +		dev_err(dev, "Failed to get PROGRAM GPIO: %d\n", ret);
> > > +		return ret;
> > > +	}
> > > +
> > > +	mgr = devm_fpga_mgr_register(dev, "Lattice ECP5 SPI FPGA Manager",
> > > +				     &ecp5_fpga_ops, priv);
> > > +
> > > +	return PTR_ERR_OR_ZERO(mgr);
> > > +}
> > > +
> > > +static const struct spi_device_id ecp5_spi_ids[] = {
> > > +	{ .name = "ecp5-fpga-mgr" },
> > > +	{},
> > > +};
> > > +MODULE_DEVICE_TABLE(spi, ecp5_spi_ids);
> > > +
> > > +#if IS_ENABLED(CONFIG_OF)
> > > +static const struct of_device_id ecp5_of_ids[] = {
> > > +	{ .compatible = "lattice,ecp5-fpga-mgr" },
> > > +	{},
> > > +};
> > > +MODULE_DEVICE_TABLE(of, ecp5_of_ids);
> > > +#endif /* IS_ENABLED(CONFIG_OF) */
> > > +
> > > +static struct spi_driver ecp5_driver = {
> > > +	.probe = ecp5_probe,
> > > +	.id_table = ecp5_spi_ids,
> > > +	.driver = {
> > > +		.name = "lattice_ecp5_spi_fpga_mgr",
> > > +		.of_match_table = of_match_ptr(ecp5_of_ids),
> > > +	},
> > > +};
> > > +
> > > +module_spi_driver(ecp5_driver);
> > > +
> > > +MODULE_DESCRIPTION("Lattice ECP5 SPI FPGA Manager");
> > > +MODULE_LICENSE("GPL");
> > > -- 
> > > 2.37.1
> > > 
> > > 
>