[PATCH 2/4] Firmware: provide a handler to program Altera FPGAs
Jean-Christophe PLAGNIOL-VILLARD
plagnioj at jcrosoft.com
Tue Nov 12 11:03:59 EST 2013
On 15:31 Tue 12 Nov , Sascha Hauer wrote:
> From: Juergen Beisert <jbe at pengutronix.de>
>
> This handler uses a regular SPI master and a few GPIOs to program an
> Altera FPGA in serial mode.
>
> Signed-off-by: Juergen Beisert <jbe at pengutronix.de>
> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
> ---
> drivers/Kconfig | 1 +
> drivers/Makefile | 1 +
> drivers/firmware/Kconfig | 11 ++
> drivers/firmware/Makefile | 1 +
> drivers/firmware/altera_serial.c | 307 +++++++++++++++++++++++++++++++++++++++
> 5 files changed, 321 insertions(+)
> create mode 100644 drivers/firmware/Kconfig
> create mode 100644 drivers/firmware/Makefile
> create mode 100644 drivers/firmware/altera_serial.c
>
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index d34d2c7..71d840c 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -25,5 +25,6 @@ source "drivers/gpio/Kconfig"
> source "drivers/w1/Kconfig"
> source "drivers/pinctrl/Kconfig"
> source "drivers/bus/Kconfig"
> +source "drivers/firmware/Kconfig"
>
> endmenu
> diff --git a/drivers/Makefile b/drivers/Makefile
> index ba1dc6d..bf03d54 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -24,3 +24,4 @@ obj-$(CONFIG_OFTREE) += of/
> obj-$(CONFIG_W1) += w1/
> obj-y += pinctrl/
> obj-y += bus/
> +obj-y += firmware/
> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
> new file mode 100644
> index 0000000..28a173b
> --- /dev/null
> +++ b/drivers/firmware/Kconfig
> @@ -0,0 +1,11 @@
> +menu "Firmware Drivers"
> +
> +config FIRMWARE_ALTERA_SERIAL
> + bool "Altera SPI programming"
> + depends on OFDEVICE
> + select FIRMWARE
> + help
> + Programming an Altera FPGA via a few GPIOs for the control lines and
> + MOSI, MISO and clock from an SPI interface for the data lines
> +
> +endmenu
> diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
> new file mode 100644
> index 0000000..ec6a5a1
> --- /dev/null
> +++ b/drivers/firmware/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_FIRMWARE_ALTERA_SERIAL) += altera_serial.o
> diff --git a/drivers/firmware/altera_serial.c b/drivers/firmware/altera_serial.c
> new file mode 100644
> index 0000000..047b6bd
> --- /dev/null
> +++ b/drivers/firmware/altera_serial.c
> @@ -0,0 +1,307 @@
> +/*
> + * Copyright (c) 2013 Juergen Beisert <kernel at pengutronix.de>, Pengutronix
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * 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 <common.h>
> +#include <init.h>
> +#include <driver.h>
> +#include <firmware.h>
> +#include <of_gpio.h>
> +#include <xfuncs.h>
> +#include <malloc.h>
> +#include <gpio.h>
> +#include <clock.h>
> +#include <spi/spi.h>
> +
> +#include <fcntl.h>
> +#include <fs.h>
> +
> +/*
> + * Physical requirements:
> + * - three free GPIOs for the signals nCONFIG, CONFIGURE_DONE, nSTATUS
> + * - 32 bit per word, LSB first capable SPI master (MOSI + clock)
> + *
> + * Example how to configure this driver via device tree
> + *
> + * fpga at 0 {
> + * compatible = "altera_serial";
> + * nstat-gpio = <&gpio4 18 0>;
> + * confd-gpio = <&gpio4 19 0>;
> + * nconfig-gpio = <&gpio4 20 0>;
you are missing on 's' to gpio mandatory for all the gpios binding
Best Regards,
J.
> + * spi-max-frequency = <10000000>;
> + * reg = <0>;
> + * };
> + */
> +
> +struct fpga_spi {
> + struct firmware_handler fh;
> + int nstat_gpio; /* input GPIO to read the status line */
> + int confd_gpio; /* input GPIO to read the config done line */
> + int nconfig_gpio; /* output GPIO to start the FPGA's config */
> + struct device_d *dev;
> + struct spi_device *spi;
> + bool padding_done;
> +};
> +
> +static int altera_spi_open(struct firmware_handler *fh)
> +{
> + struct fpga_spi *this = container_of(fh, struct fpga_spi, fh);
> + struct device_d *dev = this->dev;
> + int ret;
> +
> + dev_dbg(dev, "Initiating programming\n");
> +
> + /* initiate an FPGA programming */
> + gpio_set_value(this->nconfig_gpio, 0);
> +
> + /*
> + * after about 2 µs the FPGA must acknowledge with
> + * STATUS and CONFIG DONE lines at low level
> + */
> + ret = wait_on_timeout(2 * 1000,
> + (gpio_get_value(this->nstat_gpio) == 0) &&
> + (gpio_get_value(this->confd_gpio) == 0));
> +
> + if (ret != 0) {
> + dev_err(dev, "FPGA does not acknowledge the programming initiation\n");
> + if (gpio_get_value(this->nstat_gpio))
> + dev_err(dev, "STATUS is still high!\n");
> + if (gpio_get_value(this->confd_gpio))
> + dev_err(dev, "CONFIG DONE is still high!\n");
> + return ret;
> + }
> +
> + /* arm the FPGA to await its new firmware */
> + gpio_set_value(this->nconfig_gpio, 1);
no one check the return of gpio_set but we need to
on a i2c-gpio it might fail
> +
> + /* once again, we might need padding the data */
> + this->padding_done = false;
> +
> + /*
> + * after about 1506 µs the FPGA must acknowledge this step
> + * with the STATUS line at high level
> + */
> + ret = wait_on_timeout(1600 * 1000,
> + gpio_get_value(this->nstat_gpio) == 1);
> + if (ret != 0) {
> + dev_err(dev, "FPGA does not acknowledge the programming start\n");
> + return ret;
> + }
> +
> + dev_dbg(dev, "Initiating passed\n");
> + /* at the end, wait at least 2 µs prior beginning writing data */
> + ndelay(2 * 1000);
so udelay(2);
> +
> + return 0;
> +}
> +
> +static int altera_spi_write(struct firmware_handler *fh, const void *buf, size_t sz)
> +{
> + struct fpga_spi *this = container_of(fh, struct fpga_spi, fh);
> + struct device_d *dev = this->dev;
> + struct spi_transfer t[2];
> + struct spi_message m;
> + u32 dummy;
> + int ret;
> +
> + printf("%s: %d\n", __func__, sz);
> +
> + spi_message_init(&m);
> +
> + if (sz < sizeof(u32)) {
> + /* simple padding */
> + dummy = 0;
> + memcpy(&dummy, buf, sz);
> + buf = &dummy;
> + sz = sizeof(u32);
> + this->padding_done = true;
> + }
> +
> + t[0].tx_buf = buf;
> + t[0].rx_buf = NULL;
> + t[0].len = sz;
> + spi_message_add_tail(&t[0], &m);
> +
> + if (sz & 0x3) { /* padding required? */
> + u32 *word_buf = (u32 *)buf;
> + dummy = 0;
> + memcpy(&dummy, &word_buf[sz >> 2], sz & 0x3);
> + t[0].len &= ~0x03;
> + t[1].tx_buf = &dummy;
> + t[1].rx_buf = NULL;
> + t[1].len = sizeof(u32);
> + spi_message_add_tail(&t[1], &m);
> + this->padding_done = true;
> + }
> +
> + ret = spi_sync(this->spi, &m);
> + if (ret != 0)
> + dev_err(dev, "programming failure\n");
> +
> + return ret;
> +}
> +
> +static int altera_spi_close(struct firmware_handler *fh)
> +{
> + struct fpga_spi *this = container_of(fh, struct fpga_spi, fh);
> + struct device_d *dev = this->dev;
> + struct spi_transfer t;
> + struct spi_message m;
> + u32 dummy = 0;
> + int ret;
> +
> + dev_dbg(dev, "Finalize programming\n");
> +
> + if (this->padding_done == false) {
> + spi_message_init(&m);
> + t.tx_buf = &dummy;
> + t.rx_buf = NULL;
> + t.len = sizeof(dummy);
> + spi_message_add_tail(&t, &m);
> +
> + ret = spi_sync(this->spi, &m);
> + if (ret != 0)
> + dev_err(dev, "programming failure\n");
> + }
> +
> + /*
> + * when programming was successfully,
> + * both status lines should be at high level
> + */
> + ret = wait_on_timeout(10 * 1000,
> + (gpio_get_value(this->nstat_gpio) == 1) &&
> + (gpio_get_value(this->confd_gpio) == 1));
> + if (ret == 0) {
> + dev_dbg(dev, "Programming successfull\n");
> + return ret;
> + }
> +
> + dev_err(dev, "Programming failed due to time out\n");
> + if (gpio_get_value(this->nstat_gpio) == 0)
> + dev_err(dev, "STATUS is still low!\n");
> + if (gpio_get_value(this->confd_gpio) == 0)
> + dev_err(dev, "CONFIG DONE is still low!\n");
> +
> + return -EIO;
> +}
> +
> +static int altera_spi_of(struct device_d *dev, struct fpga_spi *this)
> +{
> + struct device_node *n = dev->device_node;
> + const char *name;
> + int ret;
> +
> + name = "nstat-gpio";
> + this->nstat_gpio = of_get_named_gpio(n, name, 0);
> + if (this->nstat_gpio < 0) {
> + ret = this->nstat_gpio;
> + goto out;
> + }
> +
> + name = "confd-gpio";
> + this->confd_gpio = of_get_named_gpio(n, name, 0);
> + if (this->confd_gpio < 0) {
> + ret = this->confd_gpio;
> + goto out;
> + }
> +
> + name = "nconfig-gpio";
> + this->nconfig_gpio = of_get_named_gpio(n, name, 0);
> + if (this->nconfig_gpio < 0) {
> + ret = this->nconfig_gpio;
> + goto out;
> + }
> +
> + /* init to passive and sane values */
> + gpio_direction_output(this->nconfig_gpio, 1);
> + gpio_direction_input(this->nstat_gpio);
> + gpio_direction_input(this->confd_gpio);
we need to check the return and request the gpio correctly
> +
> + return 0;
> +
> +out:
> + dev_err(dev, "Cannot request \"%s\" gpio: %s\n", name, strerror(-ret));
> +
> + return ret;
> +}
> +
> +static void altera_spi_init_mode(struct spi_device *spi)
> +{
> + spi->bits_per_word = 32;
> + /*
> + * CPHA = CPOL = 0
> + * the FPGA expects its firmware data with LSB first
> + */
> + spi->mode = SPI_MODE_0 | SPI_LSB_FIRST;
> +}
> +
> +static int altera_spi_probe(struct device_d *dev)
> +{
> + int rc;
> + struct fpga_spi *this;
> + struct firmware_handler *fh;
> + const char *alias = of_alias_get(dev->device_node);
> + const char *model = NULL;
> +
> + dev_dbg(dev, "Probing FPGA firmware programmer\n");
> +
> + this = xzalloc(sizeof(*this));
> + fh = &this->fh;
> +
> + rc = altera_spi_of(dev, this);
> + if (rc != 0)
> + goto out;
> +
> + if (alias)
> + fh->id = xstrdup(alias);
> + else
> + fh->id = xstrdup("altera-fpga");
> +
> + fh->open = altera_spi_open;
> + fh->write = altera_spi_write;
> + fh->close = altera_spi_close;
> + of_property_read_string(dev->device_node, "compatible", &model);
> + if (model)
> + fh->model = xstrdup(model);
> + fh->dev = dev;
> +
> + this->spi = (struct spi_device *)dev->type_data;
> + altera_spi_init_mode(this->spi);
> + this->dev = dev;
> +
> + dev_dbg(dev, "Registering FPGA firmware programmer\n");
> + rc = firmwaremgr_register(fh);
> + if (rc != 0) {
> + free(this);
> + goto out;
> + }
> +
> + return 0;
> +out:
> + free(fh->id);
> + free(this);
> +
> + return rc;
> +}
> +
> +static struct of_device_id altera_spi_id_table[] = {
> + {
> + .compatible = "altr,passive-serial",
> + },
> +};
> +
> +static struct driver_d altera_spi_driver = {
> + .name = "altera-fpga",
> + .of_compatible = DRV_OF_COMPAT(altera_spi_id_table),
> + .probe = altera_spi_probe,
> +};
> +device_spi_driver(altera_spi_driver);
> --
> 1.8.4.2
>
>
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