[PATCH v12 3/6] fpga manager: Add altera-ps-spi driver for Altera FPGAs
Joshua Clayton
stillcompiling at gmail.com
Fri Jun 2 13:30:49 PDT 2017
altera-ps-spi loads FPGA firmware over SPI, using the "passive serial"
interface on Altera Arria 10, Cyclone V or Stratix V FPGAs.
This is one of the simpler ways to set up an FPGA at runtime.
The signal interface is close to unidirectional SPI with lsb first.
Signed-off-by: Joshua Clayton <stillcompiling at gmail.com>
Signed-off-by: Anatolij Gustschin <agust at denx.de>
---
drivers/fpga/Kconfig | 7 +
drivers/fpga/Makefile | 1 +
drivers/fpga/altera-ps-spi.c | 297 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 305 insertions(+)
create mode 100644 drivers/fpga/altera-ps-spi.c
diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index 161ba9dccede..00e4cae7b79e 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -26,6 +26,13 @@ config FPGA_MGR_ICE40_SPI
help
FPGA manager driver support for Lattice iCE40 FPGAs over SPI.
+config FPGA_MGR_ALTERA_PS_SPI
+ tristate "Altera FPGA Passive Serial over SPI"
+ depends on SPI || COMPILE_TEST
+ help
+ FPGA manager driver support for Altera Arria/Cyclone/Stratix
+ using the passive serial interface over SPI.
+
config FPGA_MGR_SOCFPGA
tristate "Altera SOCFPGA FPGA Manager"
depends on ARCH_SOCFPGA || COMPILE_TEST
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index 2a4f0218145c..e75d3570e26a 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -6,6 +6,7 @@
obj-$(CONFIG_FPGA) += fpga-mgr.o
# FPGA Manager Drivers
+obj-$(CONFIG_FPGA_MGR_ALTERA_PS_SPI) += altera-ps-spi.o
obj-$(CONFIG_FPGA_MGR_ICE40_SPI) += ice40-spi.o
obj-$(CONFIG_FPGA_MGR_SOCFPGA) += socfpga.o
obj-$(CONFIG_FPGA_MGR_SOCFPGA_A10) += socfpga-a10.o
diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
new file mode 100644
index 000000000000..0db8def668ed
--- /dev/null
+++ b/drivers/fpga/altera-ps-spi.c
@@ -0,0 +1,297 @@
+/*
+ * Altera Passive Serial SPI Driver
+ *
+ * Copyright (c) 2017 United Western Technologies, Corporation
+ *
+ * Joshua Clayton <stillcompiling at gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * Manage Altera FPGA firmware that is loaded over SPI using the passive
+ * serial configuration method.
+ * Firmware must be in binary "rbf" format.
+ * Works on Arria 10, Cyclone V and Stratix V. Should work on Cyclone series.
+ * May work on other Altera FPGAs.
+ */
+
+#include <linux/bitrev.h>
+#include <linux/delay.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/of_device.h>
+#include <linux/spi/spi.h>
+#include <linux/sizes.h>
+
+enum altera_ps_devtype {
+ CYCLONE5,
+ ARRIA10,
+};
+
+struct altera_ps_data {
+ enum altera_ps_devtype devtype;
+ int status_wait_min_us;
+ int status_wait_max_us;
+ int t_cfg_us;
+ int t_st2ck_us;
+};
+
+struct altera_ps_conf {
+ struct gpio_desc *config;
+ struct gpio_desc *confd;
+ struct gpio_desc *status;
+ struct spi_device *spi;
+ const struct altera_ps_data *data;
+ u32 info_flags;
+ char mgr_name[64];
+};
+
+/* | Arria 10 | Cyclone5 | Stratix5 |
+ * t_CF2ST0 | [; 600] | [; 600] | [; 600] |ns
+ * t_CFG | [2;] | [2;] | [2;] |µs
+ * t_STATUS | [268; 3000] | [268; 1506] | [268; 1506] |µs
+ * t_CF2ST1 | [; 3000] | [; 1506] | [; 1506] |µs
+ * t_CF2CK | [3010;] | [1506;] | [1506;] |µs
+ * t_ST2CK | [10;] | [2;] | [2;] |µs
+ * t_CD2UM | [175; 830] | [175; 437] | [175; 437] |µs
+ */
+static struct altera_ps_data c5_data = {
+ /* these values for Cyclone5 are compatible with Stratix5 */
+ .devtype = CYCLONE5,
+ .status_wait_min_us = 268,
+ .status_wait_max_us = 1506,
+ .t_cfg_us = 2,
+ .t_st2ck_us = 2,
+};
+
+static struct altera_ps_data a10_data = {
+ .devtype = ARRIA10,
+ .status_wait_min_us = 268, /* min(t_STATUS) */
+ .status_wait_max_us = 3000, /* max(t_CF2ST1) */
+ .t_cfg_us = 2, /* max { min(t_CFG), max(tCF2ST0) } */
+ .t_st2ck_us = 10, /* min(t_ST2CK) */
+};
+
+static const struct of_device_id of_ef_match[] = {
+ { .compatible = "altr,fpga-passive-serial", .data = &c5_data },
+ { .compatible = "altr,fpga-arria10-passive-serial", .data = &a10_data },
+ {}
+};
+MODULE_DEVICE_TABLE(of, of_ef_match);
+
+static enum fpga_mgr_states altera_ps_state(struct fpga_manager *mgr)
+{
+ struct altera_ps_conf *conf = mgr->priv;
+
+ if (gpiod_get_value_cansleep(conf->status))
+ return FPGA_MGR_STATE_RESET;
+
+ return FPGA_MGR_STATE_UNKNOWN;
+}
+
+static inline void altera_ps_delay(int delay_us)
+{
+ if (delay_us > 10)
+ usleep_range(delay_us, delay_us + 5);
+ else
+ udelay(delay_us);
+}
+
+static int altera_ps_write_init(struct fpga_manager *mgr,
+ struct fpga_image_info *info,
+ const char *buf, size_t count)
+{
+ struct altera_ps_conf *conf = mgr->priv;
+ int min, max, waits;
+ int i;
+
+ conf->info_flags = info->flags;
+
+ if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
+ dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
+ return -EINVAL;
+ }
+
+ gpiod_set_value_cansleep(conf->config, 1);
+
+ /* wait min reset pulse time */
+ altera_ps_delay(conf->data->t_cfg_us);
+
+ if (!gpiod_get_value_cansleep(conf->status)) {
+ dev_err(&mgr->dev, "Status pin failed to show a reset\n");
+ return -EIO;
+ }
+
+ gpiod_set_value_cansleep(conf->config, 0);
+
+ min = conf->data->status_wait_min_us;
+ max = conf->data->status_wait_max_us;
+ waits = max / min;
+ if (max % min)
+ waits++;
+
+ /* wait for max { max(t_STATUS), max(t_CF2ST1) } */
+ for (i = 0; i < waits; i++) {
+ usleep_range(min, min + 10);
+ if (!gpiod_get_value_cansleep(conf->status)) {
+ /* wait for min(t_ST2CK)*/
+ altera_ps_delay(conf->data->t_st2ck_us);
+ return 0;
+ }
+ }
+
+ dev_err(&mgr->dev, "Status pin not ready.\n");
+ return -EIO;
+}
+
+static void rev_buf(char *buf, size_t len)
+{
+ const char *fw_end = (buf + len);
+
+ /* set buffer to lsb first */
+ while (buf < fw_end) {
+ *buf = bitrev8(*buf);
+ buf++;
+ }
+}
+
+static int altera_ps_write(struct fpga_manager *mgr, const char *buf,
+ size_t count)
+{
+ struct altera_ps_conf *conf = mgr->priv;
+ const char *fw_data = buf;
+ const char *fw_data_end = fw_data + count;
+
+ while (fw_data < fw_data_end) {
+ int ret;
+ size_t stride = min_t(size_t, fw_data_end - fw_data, SZ_4K);
+
+ if (!(conf->info_flags & FPGA_MGR_BITSTREAM_LSB_FIRST))
+ rev_buf((char *)fw_data, stride);
+
+ ret = spi_write(conf->spi, fw_data, stride);
+ if (ret) {
+ dev_err(&mgr->dev, "spi error in firmware write: %d\n",
+ ret);
+ return ret;
+ }
+ fw_data += stride;
+ }
+
+ return 0;
+}
+
+static int altera_ps_write_complete(struct fpga_manager *mgr,
+ struct fpga_image_info *info)
+{
+ struct altera_ps_conf *conf = mgr->priv;
+ const char dummy[] = {0};
+ int ret;
+
+ if (gpiod_get_value_cansleep(conf->status)) {
+ dev_err(&mgr->dev, "Error during configuration.\n");
+ return -EIO;
+ }
+
+ if (!IS_ERR(conf->confd)) {
+ if (!gpiod_get_raw_value_cansleep(conf->confd)) {
+ dev_err(&mgr->dev, "CONF_DONE is inactive!\n");
+ return -EIO;
+ }
+ }
+
+ /*
+ * After CONF_DONE goes high, send two additional falling edges on DCLK
+ * to begin initialization and enter user mode
+ */
+ ret = spi_write(conf->spi, dummy, 1);
+ if (ret) {
+ dev_err(&mgr->dev, "spi error during end sequence: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct fpga_manager_ops altera_ps_ops = {
+ .state = altera_ps_state,
+ .write_init = altera_ps_write_init,
+ .write = altera_ps_write,
+ .write_complete = altera_ps_write_complete,
+};
+
+static int altera_ps_probe(struct spi_device *spi)
+{
+ struct altera_ps_conf *conf;
+ const struct of_device_id *of_id;
+
+ conf = devm_kzalloc(&spi->dev, sizeof(*conf), GFP_KERNEL);
+ if (!conf)
+ return -ENOMEM;
+
+ of_id = of_match_device(of_ef_match, &spi->dev);
+ if (!of_id)
+ return -ENODEV;
+
+ conf->data = of_id->data;
+ conf->spi = spi;
+ conf->config = devm_gpiod_get(&spi->dev, "nconfig", GPIOD_OUT_HIGH);
+ if (IS_ERR(conf->config)) {
+ dev_err(&spi->dev, "Failed to get config gpio: %ld\n",
+ PTR_ERR(conf->config));
+ return PTR_ERR(conf->config);
+ }
+
+ conf->status = devm_gpiod_get(&spi->dev, "nstat", GPIOD_IN);
+ if (IS_ERR(conf->status)) {
+ dev_err(&spi->dev, "Failed to get status gpio: %ld\n",
+ PTR_ERR(conf->status));
+ return PTR_ERR(conf->status);
+ }
+
+ conf->confd = devm_gpiod_get(&spi->dev, "confd", GPIOD_IN);
+ if (IS_ERR(conf->confd)) {
+ dev_warn(&spi->dev, "Not using confd gpio: %ld\n",
+ PTR_ERR(conf->confd));
+ }
+
+ /* Register manager with unique name */
+ snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
+ dev_driver_string(&spi->dev), dev_name(&spi->dev));
+
+ return fpga_mgr_register(&spi->dev, conf->mgr_name,
+ &altera_ps_ops, conf);
+}
+
+static int altera_ps_remove(struct spi_device *spi)
+{
+ fpga_mgr_unregister(&spi->dev);
+
+ return 0;
+}
+
+static const struct spi_device_id altera_ps_spi_ids[] = {
+ {"cyclone-ps-spi", 0},
+ {}
+};
+MODULE_DEVICE_TABLE(spi, altera_ps_spi_ids);
+
+static struct spi_driver altera_ps_driver = {
+ .driver = {
+ .name = "altera-ps-spi",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(of_ef_match),
+ },
+ .id_table = altera_ps_spi_ids,
+ .probe = altera_ps_probe,
+ .remove = altera_ps_remove,
+};
+
+module_spi_driver(altera_ps_driver)
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Joshua Clayton <stillcompiling at gmail.com>");
+MODULE_DESCRIPTION("Module to load Altera FPGA firmware over SPI");
--
2.11.0
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