diff options
Diffstat (limited to 'drivers/fpga/altera-ps-spi.c')
| -rw-r--r-- | drivers/fpga/altera-ps-spi.c | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c new file mode 100644 index 0000000000..5e1e009dba --- /dev/null +++ b/drivers/fpga/altera-ps-spi.c @@ -0,0 +1,332 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Altera Passive Serial SPI Driver + * + * Copyright (c) 2017 United Western Technologies, Corporation + * + * Joshua Clayton <stillcompiling@gmail.com> + * + * 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) */ +}; + +/* Array index is enum altera_ps_devtype */ +static const struct altera_ps_data *altera_ps_data_map[] = { + &c5_data, + &a10_data, +}; + +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) +{ + u32 *fw32 = (u32 *)buf; + size_t extra_bytes = (len & 0x03); + const u32 *fw_end = (u32 *)(buf + len - extra_bytes); + + /* set buffer to lsb first */ + while (fw32 < fw_end) { + *fw32 = bitrev8x4(*fw32); + fw32++; + } + + if (extra_bytes) { + buf = (char *)fw_end; + while (extra_bytes) { + *buf = bitrev8(*buf); + buf++; + extra_bytes--; + } + } +} + +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; + static const char dummy[] = {0}; + int ret; + + if (gpiod_get_value_cansleep(conf->status)) { + dev_err(&mgr->dev, "Error during configuration.\n"); + return -EIO; + } + + if (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 const struct altera_ps_data *id_to_data(const struct spi_device_id *id) +{ + kernel_ulong_t devtype = id->driver_data; + const struct altera_ps_data *data; + + /* someone added a altera_ps_devtype without adding to the map array */ + if (devtype >= ARRAY_SIZE(altera_ps_data_map)) + return NULL; + + data = altera_ps_data_map[devtype]; + if (!data || data->devtype != devtype) + return NULL; + + return data; +} + +static int altera_ps_probe(struct spi_device *spi) +{ + struct altera_ps_conf *conf; + const struct of_device_id *of_id; + struct fpga_manager *mgr; + + conf = devm_kzalloc(&spi->dev, sizeof(*conf), GFP_KERNEL); + if (!conf) + return -ENOMEM; + + if (spi->dev.of_node) { + of_id = of_match_device(of_ef_match, &spi->dev); + if (!of_id) + return -ENODEV; + conf->data = of_id->data; + } else { + conf->data = id_to_data(spi_get_device_id(spi)); + if (!conf->data) + return -ENODEV; + } + + conf->spi = spi; + conf->config = devm_gpiod_get(&spi->dev, "nconfig", GPIOD_OUT_LOW); + 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_optional(&spi->dev, "confd", GPIOD_IN); + if (IS_ERR(conf->confd)) { + dev_err(&spi->dev, "Failed to get confd gpio: %ld\n", + PTR_ERR(conf->confd)); + return PTR_ERR(conf->confd); + } else if (!conf->confd) { + dev_warn(&spi->dev, "Not using confd gpio"); + } + + /* Register manager with unique name */ + snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s", + dev_driver_string(&spi->dev), dev_name(&spi->dev)); + + mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name, + &altera_ps_ops, conf); + return PTR_ERR_OR_ZERO(mgr); +} + +static const struct spi_device_id altera_ps_spi_ids[] = { + { "cyclone-ps-spi", CYCLONE5 }, + { "fpga-passive-serial", CYCLONE5 }, + { "fpga-arria10-passive-serial", ARRIA10 }, + {} +}; +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, +}; + +module_spi_driver(altera_ps_driver) + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Joshua Clayton <stillcompiling@gmail.com>"); +MODULE_DESCRIPTION("Module to load Altera FPGA firmware over SPI"); |