[PATCH v4 1/2] FPGA: Add TS-7300 FPGA manager

[Alan Tull]

On Sun, 18 Dec 2016, Florian Fainelli wrote:

Hi Florain,

> Add support for loading bitstreams on the Altera Cyclone II FPGA
> populated on the TS-7300 board. This is done through the configuration
> and data registers offered through a memory interface between the EP93xx
> SoC and the FPGA via an intermediate CPLD device.
> 
> The EP93xx SoC on the TS-7300 does not have direct means of configuring
> the on-board FPGA other than by using the special memory mapped
> interface to the CPLD. No other entity on the system can control the
> FPGA bitstream.
> 
> Signed-off-by: Florian Fainelli <f.fainelli at gmail.com>
> ---
>  drivers/fpga/Kconfig       |   7 ++
>  drivers/fpga/Makefile      |   1 +
>  drivers/fpga/ts73xx-fpga.c | 163 +++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 171 insertions(+)
>  create mode 100644 drivers/fpga/ts73xx-fpga.c
> 
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index ce861a2853a4..d9cbef60db80 100644
> --- a/drivers/fpga/Kconfig
> +++ b/drivers/fpga/Kconfig
> @@ -33,6 +33,13 @@ config FPGA_MGR_SOCFPGA_A10
>  	help
>  	  FPGA manager driver support for Altera Arria10 SoCFPGA.
>  
> +config FPGA_MGR_TS73XX
> +	tristate "Technologic Systems TS-73xx SBC FPGA Manager"
> +	depends on ARCH_EP93XX && MACH_TS72XX
> +	help
> +	  FPGA manager driver support for the Altera Cyclone II FPGA
> +	  present on the TS-73xx SBC boards.
> +
>  config FPGA_MGR_ZYNQ_FPGA
>  	tristate "Xilinx Zynq FPGA"
>  	depends on ARCH_ZYNQ || COMPILE_TEST
> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> index 8df07bcf42a6..a1160169e6d9 100644
> --- a/drivers/fpga/Makefile
> +++ b/drivers/fpga/Makefile
> @@ -8,6 +8,7 @@ obj-$(CONFIG_FPGA)			+= fpga-mgr.o
>  # FPGA Manager Drivers
>  obj-$(CONFIG_FPGA_MGR_SOCFPGA)		+= socfpga.o
>  obj-$(CONFIG_FPGA_MGR_SOCFPGA_A10)	+= socfpga-a10.o
> +obj-$(CONFIG_FPGA_MGR_TS73XX)		+= ts73xx-fpga.o
>  obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA)	+= zynq-fpga.o
>  
>  # FPGA Bridge Drivers
> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
> new file mode 100644
> index 000000000000..5acdbcfe447b
> --- /dev/null
> +++ b/drivers/fpga/ts73xx-fpga.c
> @@ -0,0 +1,163 @@
> +/*
> + * Technologic Systems TS-73xx SBC FPGA loader
> + *
> + * Copyright (C) 2016 Florian Fainelli <f.fainelli at gmail.com>
> + *
> + * FPGA Manager Driver for the on-board Altera Cyclone II FPGA found on
> + * TS-7300, heavily based on load_fpga.c in their vendor tree.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; version 2 of the License.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/string.h>
> +#include <linux/iopoll.h>
> +#include <linux/fpga/fpga-mgr.h>
> +
> +#define TS73XX_FPGA_DATA_REG		0
> +#define TS73XX_FPGA_CONFIG_REG		1
> +
> +#define TS73XX_FPGA_WRITE_DONE		0x1
> +#define TS73XX_FPGA_WRITE_DONE_TIMEOUT	1000	/* us */

If you add units to these timeouts/delays, it could prevent
issues in the future.  Such as _USEC

> +#define TS73XX_FPGA_RESET		0x2
> +#define TS73XX_FPGA_RESET_LOW_DELAY	30	/* us */
> +#define TS73XX_FPGA_RESET_HIGH_DELAY	80	/* us */
> +#define TS73XX_FPGA_LOAD_OK		0x4
> +#define TS73XX_FPGA_CONFIG_LOAD		0x8
> +
> +struct ts73xx_fpga_priv {
> +	void __iomem	*io_base;
> +	struct device	*dev;
> +};
> +
> +static enum fpga_mgr_states ts73xx_fpga_state(struct fpga_manager *mgr)
> +{
> +	return FPGA_MGR_STATE_UNKNOWN;
> +}
> +
> +static int ts73xx_fpga_write_init(struct fpga_manager *mgr,
> +				  struct fpga_image_info *info,
> +				  const char *buf, size_t count)
> +{
> +	struct ts73xx_fpga_priv *priv = mgr->priv;
> +
> +	/* Reset the FPGA */
> +	writeb(0, priv->io_base + TS73XX_FPGA_CONFIG_REG);
> +	udelay(TS73XX_FPGA_RESET_LOW_DELAY);
> +	writeb(TS73XX_FPGA_RESET, priv->io_base + TS73XX_FPGA_CONFIG_REG);
> +	udelay(TS73XX_FPGA_RESET_HIGH_DELAY);
> +
> +	return 0;
> +}
> +
> +static int ts73xx_fpga_write(struct fpga_manager *mgr, const char *buf,
> +			     size_t count)
> +{
> +	struct ts73xx_fpga_priv *priv = mgr->priv;
> +	size_t i = 0;
> +	int ret;
> +	u8 reg;
> +
> +	while (count--) {
> +		ret = readb_poll_timeout(priv->io_base + TS73XX_FPGA_CONFIG_REG,
> +					 reg, !(reg & TS73XX_FPGA_WRITE_DONE),
> +					 1, TS73XX_FPGA_WRITE_DONE_TIMEOUT);
> +		if (ret < 0)
> +			return ret;
> +
> +		writeb(buf[i], priv->io_base + TS73XX_FPGA_DATA_REG);
> +		i++;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ts73xx_fpga_write_complete(struct fpga_manager *mgr,
> +				      struct fpga_image_info *info)
> +{
> +	struct ts73xx_fpga_priv *priv = mgr->priv;
> +	u8 reg;
> +
> +	usleep_range(1000, 2000);
> +	reg = readb(priv->io_base + TS73XX_FPGA_CONFIG_REG);
> +	reg |= TS73XX_FPGA_CONFIG_LOAD;
> +	writeb(reg, priv->io_base + TS73XX_FPGA_CONFIG_REG);
> +
> +	usleep_range(1000, 2000);
> +	reg = readb(priv->io_base + TS73XX_FPGA_CONFIG_REG);
> +	reg &= ~TS73XX_FPGA_CONFIG_LOAD;
> +	writeb(reg, priv->io_base + TS73XX_FPGA_CONFIG_REG);
> +
> +	reg = readb(priv->io_base + TS73XX_FPGA_CONFIG_REG);
> +	if ((reg & TS73XX_FPGA_LOAD_OK) != TS73XX_FPGA_LOAD_OK)
> +		return -ETIMEDOUT;
> +
> +	return 0;
> +}
> +
> +static const struct fpga_manager_ops ts73xx_fpga_ops = {
> +	.state		= ts73xx_fpga_state,
> +	.write_init	= ts73xx_fpga_write_init,
> +	.write		= ts73xx_fpga_write,
> +	.write_complete	= ts73xx_fpga_write_complete,
> +};
> +
> +static int ts73xx_fpga_probe(struct platform_device *pdev)
> +{
> +	struct device *kdev = &pdev->dev;
> +	struct ts73xx_fpga_priv *priv;
> +	struct resource *res;
> +	int err;
> +
> +	priv = devm_kzalloc(kdev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->dev = kdev;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	priv->io_base = devm_ioremap_resource(kdev, res);
> +	if (IS_ERR(priv->io_base)) {
> +		dev_err(kdev, "unable to remap registers\n");
> +		return PTR_ERR(priv->io_base);
> +	}
> +
> +	err = fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
> +				&ts73xx_fpga_ops, priv);
> +	if (err) {
> +		dev_err(kdev, "failed to register FPGA manager\n");
> +		return err;
> +	}


You can just 'return fpga_mgr_register(..); here.

Thanks for your responsiveness.  You can leave things up longer so
that people have time to review.  That way you don't have to go
through so many versions so quickly.

Acked-by: Alan Tull <atull at opensource.altera.com>

Thanks,
Alan

> +
> +	return err;
> +}
> +
> +static int ts73xx_fpga_remove(struct platform_device *pdev)
> +{
> +	fpga_mgr_unregister(&pdev->dev);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver ts73xx_fpga_driver = {
> +	.driver	= {
> +		.name	= "ts73xx-fpga-mgr",
> +	},
> +	.probe	= ts73xx_fpga_probe,
> +	.remove	= ts73xx_fpga_remove,
> +};
> +module_platform_driver(ts73xx_fpga_driver);
> +
> +MODULE_AUTHOR("Florian Fainelli <f.fainelli at gmail.com>");
> +MODULE_DESCRIPTION("TS-73xx FPGA Manager driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.9.3
> 
>