diff options
Diffstat (limited to 'drivers/fpga/machxo2-spi.c')
| -rw-r--r-- | drivers/fpga/machxo2-spi.c | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c new file mode 100644 index 000000000..fa76239f9 --- /dev/null +++ b/drivers/fpga/machxo2-spi.c @@ -0,0 +1,419 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Lattice MachXO2 Slave SPI Driver + * + * Manage Lattice FPGA firmware that is loaded over SPI using + * the slave serial configuration interface. + * + * Copyright (C) 2018 Paolo Pisati <p.pisati@gmail.com> + */ + +#include <linux/delay.h> +#include <linux/fpga/fpga-mgr.h> +#include <linux/gpio/consumer.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/spi/spi.h> + +/* MachXO2 Programming Guide - sysCONFIG Programming Commands */ +#define IDCODE_PUB {0xe0, 0x00, 0x00, 0x00} +#define ISC_ENABLE {0xc6, 0x08, 0x00, 0x00} +#define ISC_ERASE {0x0e, 0x04, 0x00, 0x00} +#define ISC_PROGRAMDONE {0x5e, 0x00, 0x00, 0x00} +#define LSC_INITADDRESS {0x46, 0x00, 0x00, 0x00} +#define LSC_PROGINCRNV {0x70, 0x00, 0x00, 0x01} +#define LSC_READ_STATUS {0x3c, 0x00, 0x00, 0x00} +#define LSC_REFRESH {0x79, 0x00, 0x00, 0x00} + +/* + * Max CCLK in Slave SPI mode according to 'MachXO2 Family Data + * Sheet' sysCONFIG Port Timing Specifications (3-36) + */ +#define MACHXO2_MAX_SPEED 66000000 + +#define MACHXO2_LOW_DELAY_USEC 5 +#define MACHXO2_HIGH_DELAY_USEC 200 +#define MACHXO2_REFRESH_USEC 4800 +#define MACHXO2_MAX_BUSY_LOOP 128 +#define MACHXO2_MAX_REFRESH_LOOP 16 + +#define MACHXO2_PAGE_SIZE 16 +#define MACHXO2_BUF_SIZE (MACHXO2_PAGE_SIZE + 4) + +/* Status register bits, errors and error mask */ +#define BUSY 12 +#define DONE 8 +#define DVER 27 +#define ENAB 9 +#define ERRBITS 23 +#define ERRMASK 7 +#define FAIL 13 + +#define ENOERR 0 /* no error */ +#define EID 1 +#define ECMD 2 +#define ECRC 3 +#define EPREAM 4 /* preamble error */ +#define EABRT 5 /* abort error */ +#define EOVERFL 6 /* overflow error */ +#define ESDMEOF 7 /* SDM EOF */ + +static inline u8 get_err(unsigned long *status) +{ + return (*status >> ERRBITS) & ERRMASK; +} + +static int get_status(struct spi_device *spi, unsigned long *status) +{ + struct spi_message msg; + struct spi_transfer rx, tx; + static const u8 cmd[] = LSC_READ_STATUS; + int ret; + + memset(&rx, 0, sizeof(rx)); + memset(&tx, 0, sizeof(tx)); + tx.tx_buf = cmd; + tx.len = sizeof(cmd); + rx.rx_buf = status; + rx.len = 4; + spi_message_init(&msg); + spi_message_add_tail(&tx, &msg); + spi_message_add_tail(&rx, &msg); + ret = spi_sync(spi, &msg); + if (ret) + return ret; + + *status = be32_to_cpu(*status); + + return 0; +} + +#ifdef DEBUG +static const char *get_err_string(u8 err) +{ + switch (err) { + case ENOERR: return "No Error"; + case EID: return "ID ERR"; + case ECMD: return "CMD ERR"; + case ECRC: return "CRC ERR"; + case EPREAM: return "Preamble ERR"; + case EABRT: return "Abort ERR"; + case EOVERFL: return "Overflow ERR"; + case ESDMEOF: return "SDM EOF"; + } + + return "Default switch case"; +} +#endif + +static void dump_status_reg(unsigned long *status) +{ +#ifdef DEBUG + pr_debug("machxo2 status: 0x%08lX - done=%d, cfgena=%d, busy=%d, fail=%d, devver=%d, err=%s\n", + *status, test_bit(DONE, status), test_bit(ENAB, status), + test_bit(BUSY, status), test_bit(FAIL, status), + test_bit(DVER, status), get_err_string(get_err(status))); +#endif +} + +static int wait_until_not_busy(struct spi_device *spi) +{ + unsigned long status; + int ret, loop = 0; + + do { + ret = get_status(spi, &status); + if (ret) + return ret; + if (++loop >= MACHXO2_MAX_BUSY_LOOP) + return -EBUSY; + } while (test_bit(BUSY, &status)); + + return 0; +} + +static int machxo2_cleanup(struct fpga_manager *mgr) +{ + struct spi_device *spi = mgr->priv; + struct spi_message msg; + struct spi_transfer tx[2]; + static const u8 erase[] = ISC_ERASE; + static const u8 refresh[] = LSC_REFRESH; + int ret; + + memset(tx, 0, sizeof(tx)); + spi_message_init(&msg); + tx[0].tx_buf = &erase; + tx[0].len = sizeof(erase); + spi_message_add_tail(&tx[0], &msg); + ret = spi_sync(spi, &msg); + if (ret) + goto fail; + + ret = wait_until_not_busy(spi); + if (ret) + goto fail; + + spi_message_init(&msg); + tx[1].tx_buf = &refresh; + tx[1].len = sizeof(refresh); + tx[1].delay_usecs = MACHXO2_REFRESH_USEC; + spi_message_add_tail(&tx[1], &msg); + ret = spi_sync(spi, &msg); + if (ret) + goto fail; + + return 0; +fail: + dev_err(&mgr->dev, "Cleanup failed\n"); + + return ret; +} + +static enum fpga_mgr_states machxo2_spi_state(struct fpga_manager *mgr) +{ + struct spi_device *spi = mgr->priv; + unsigned long status; + + get_status(spi, &status); + if (!test_bit(BUSY, &status) && test_bit(DONE, &status) && + get_err(&status) == ENOERR) + return FPGA_MGR_STATE_OPERATING; + + return FPGA_MGR_STATE_UNKNOWN; +} + +static int machxo2_write_init(struct fpga_manager *mgr, + struct fpga_image_info *info, + const char *buf, size_t count) +{ + struct spi_device *spi = mgr->priv; + struct spi_message msg; + struct spi_transfer tx[3]; + static const u8 enable[] = ISC_ENABLE; + static const u8 erase[] = ISC_ERASE; + static const u8 initaddr[] = LSC_INITADDRESS; + unsigned long status; + int ret; + + if ((info->flags & FPGA_MGR_PARTIAL_RECONFIG)) { + dev_err(&mgr->dev, + "Partial reconfiguration is not supported\n"); + return -ENOTSUPP; + } + + get_status(spi, &status); + dump_status_reg(&status); + memset(tx, 0, sizeof(tx)); + spi_message_init(&msg); + tx[0].tx_buf = &enable; + tx[0].len = sizeof(enable); + tx[0].delay_usecs = MACHXO2_LOW_DELAY_USEC; + spi_message_add_tail(&tx[0], &msg); + + tx[1].tx_buf = &erase; + tx[1].len = sizeof(erase); + spi_message_add_tail(&tx[1], &msg); + ret = spi_sync(spi, &msg); + if (ret) + goto fail; + + ret = wait_until_not_busy(spi); + if (ret) + goto fail; + + get_status(spi, &status); + if (test_bit(FAIL, &status)) { + ret = -EINVAL; + goto fail; + } + dump_status_reg(&status); + + spi_message_init(&msg); + tx[2].tx_buf = &initaddr; + tx[2].len = sizeof(initaddr); + spi_message_add_tail(&tx[2], &msg); + ret = spi_sync(spi, &msg); + if (ret) + goto fail; + + get_status(spi, &status); + dump_status_reg(&status); + + return 0; +fail: + dev_err(&mgr->dev, "Error during FPGA init.\n"); + + return ret; +} + +static int machxo2_write(struct fpga_manager *mgr, const char *buf, + size_t count) +{ + struct spi_device *spi = mgr->priv; + struct spi_message msg; + struct spi_transfer tx; + static const u8 progincr[] = LSC_PROGINCRNV; + u8 payload[MACHXO2_BUF_SIZE]; + unsigned long status; + int i, ret; + + if (count % MACHXO2_PAGE_SIZE != 0) { + dev_err(&mgr->dev, "Malformed payload.\n"); + return -EINVAL; + } + get_status(spi, &status); + dump_status_reg(&status); + memcpy(payload, &progincr, sizeof(progincr)); + for (i = 0; i < count; i += MACHXO2_PAGE_SIZE) { + memcpy(&payload[sizeof(progincr)], &buf[i], MACHXO2_PAGE_SIZE); + memset(&tx, 0, sizeof(tx)); + spi_message_init(&msg); + tx.tx_buf = payload; + tx.len = MACHXO2_BUF_SIZE; + tx.delay_usecs = MACHXO2_HIGH_DELAY_USEC; + spi_message_add_tail(&tx, &msg); + ret = spi_sync(spi, &msg); + if (ret) { + dev_err(&mgr->dev, "Error loading the bitstream.\n"); + return ret; + } + } + get_status(spi, &status); + dump_status_reg(&status); + + return 0; +} + +static int machxo2_write_complete(struct fpga_manager *mgr, + struct fpga_image_info *info) +{ + struct spi_device *spi = mgr->priv; + struct spi_message msg; + struct spi_transfer tx[2]; + static const u8 progdone[] = ISC_PROGRAMDONE; + static const u8 refresh[] = LSC_REFRESH; + unsigned long status; + int ret, refreshloop = 0; + + memset(tx, 0, sizeof(tx)); + spi_message_init(&msg); + tx[0].tx_buf = &progdone; + tx[0].len = sizeof(progdone); + spi_message_add_tail(&tx[0], &msg); + ret = spi_sync(spi, &msg); + if (ret) + goto fail; + ret = wait_until_not_busy(spi); + if (ret) + goto fail; + + get_status(spi, &status); + dump_status_reg(&status); + if (!test_bit(DONE, &status)) { + machxo2_cleanup(mgr); + ret = -EINVAL; + goto fail; + } + + do { + spi_message_init(&msg); + tx[1].tx_buf = &refresh; + tx[1].len = sizeof(refresh); + tx[1].delay_usecs = MACHXO2_REFRESH_USEC; + spi_message_add_tail(&tx[1], &msg); + ret = spi_sync(spi, &msg); + if (ret) + goto fail; + + /* check refresh status */ + get_status(spi, &status); + dump_status_reg(&status); + if (!test_bit(BUSY, &status) && test_bit(DONE, &status) && + get_err(&status) == ENOERR) + break; + if (++refreshloop == MACHXO2_MAX_REFRESH_LOOP) { + machxo2_cleanup(mgr); + ret = -EINVAL; + goto fail; + } + } while (1); + + get_status(spi, &status); + dump_status_reg(&status); + + return 0; +fail: + dev_err(&mgr->dev, "Refresh failed.\n"); + + return ret; +} + +static const struct fpga_manager_ops machxo2_ops = { + .state = machxo2_spi_state, + .write_init = machxo2_write_init, + .write = machxo2_write, + .write_complete = machxo2_write_complete, +}; + +static int machxo2_spi_probe(struct spi_device *spi) +{ + struct device *dev = &spi->dev; + struct fpga_manager *mgr; + int ret; + + if (spi->max_speed_hz > MACHXO2_MAX_SPEED) { + dev_err(dev, "Speed is too high\n"); + return -EINVAL; + } + + mgr = fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager", + &machxo2_ops, spi); + if (!mgr) + return -ENOMEM; + + spi_set_drvdata(spi, mgr); + + ret = fpga_mgr_register(mgr); + if (ret) + fpga_mgr_free(mgr); + + return ret; +} + +static int machxo2_spi_remove(struct spi_device *spi) +{ + struct fpga_manager *mgr = spi_get_drvdata(spi); + + fpga_mgr_unregister(mgr); + + return 0; +} + +static const struct of_device_id of_match[] = { + { .compatible = "lattice,machxo2-slave-spi", }, + {} +}; +MODULE_DEVICE_TABLE(of, of_match); + +static const struct spi_device_id lattice_ids[] = { + { "machxo2-slave-spi", 0 }, + { }, +}; +MODULE_DEVICE_TABLE(spi, lattice_ids); + +static struct spi_driver machxo2_spi_driver = { + .driver = { + .name = "machxo2-slave-spi", + .of_match_table = of_match_ptr(of_match), + }, + .probe = machxo2_spi_probe, + .remove = machxo2_spi_remove, + .id_table = lattice_ids, +}; + +module_spi_driver(machxo2_spi_driver) + +MODULE_AUTHOR("Paolo Pisati <p.pisati@gmail.com>"); +MODULE_DESCRIPTION("Load Lattice FPGA firmware over SPI"); +MODULE_LICENSE("GPL v2"); |