/* * Copyright (C) 2012 Stefan Roese <sr@denx.de> * * 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; either version 2 of the License, or * (at your option) any later version. */ #include <linux/device.h> #include <linux/firmware.h> #include <linux/module.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/spi/spi.h> #include <linux/platform_device.h> #include <linux/delay.h> #define FIRMWARE_NAME "lattice-ecp3.bit" /* * The JTAG ID's of the supported FPGA's. The ID is 32bit wide * reversed as noted in the manual. */ #define ID_ECP3_17 0xc2088080 #define ID_ECP3_35 0xc2048080 /* FPGA commands */ #define FPGA_CMD_READ_ID 0x07 /* plus 24 bits */ #define FPGA_CMD_READ_STATUS 0x09 /* plus 24 bits */ #define FPGA_CMD_CLEAR 0x70 #define FPGA_CMD_REFRESH 0x71 #define FPGA_CMD_WRITE_EN 0x4a /* plus 2 bits */ #define FPGA_CMD_WRITE_DIS 0x4f /* plus 8 bits */ #define FPGA_CMD_WRITE_INC 0x41 /* plus 0 bits */ /* * The status register is 32bit revered, DONE is bit 17 from the TN1222.pdf * (LatticeECP3 Slave SPI Port User's Guide) */ #define FPGA_STATUS_DONE 0x00004000 #define FPGA_STATUS_CLEARED 0x00010000 #define FPGA_CLEAR_TIMEOUT 5000 /* max. 5000ms for FPGA clear */ #define FPGA_CLEAR_MSLEEP 10 #define FPGA_CLEAR_LOOP_COUNT (FPGA_CLEAR_TIMEOUT / FPGA_CLEAR_MSLEEP) struct fpga_data { struct completion fw_loaded; }; struct ecp3_dev { u32 jedec_id; char *name; }; static const struct ecp3_dev ecp3_dev[] = { { .jedec_id = ID_ECP3_17, .name = "Lattice ECP3-17", }, { .jedec_id = ID_ECP3_35, .name = "Lattice ECP3-35", }, }; static void firmware_load(const struct firmware *fw, void *context) { struct spi_device *spi = (struct spi_device *)context; struct fpga_data *data = dev_get_drvdata(&spi->dev); u8 *buffer; int ret; u8 txbuf[8]; u8 rxbuf[8]; int rx_len = 8; int i; u32 jedec_id; u32 status; if (fw->size == 0) { dev_err(&spi->dev, "Error: Firmware size is 0!\n"); return; } /* Fill dummy data (24 stuffing bits for commands) */ txbuf[1] = 0x00; txbuf[2] = 0x00; txbuf[3] = 0x00; /* Trying to speak with the FPGA via SPI... */ txbuf[0] = FPGA_CMD_READ_ID; ret = spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len); dev_dbg(&spi->dev, "FPGA JTAG ID=%08x\n", *(u32 *)&rxbuf[4]); jedec_id = *(u32 *)&rxbuf[4]; for (i = 0; i < ARRAY_SIZE(ecp3_dev); i++) { if (jedec_id == ecp3_dev[i].jedec_id) break; } if (i == ARRAY_SIZE(ecp3_dev)) { dev_err(&spi->dev, "Error: No supported FPGA detected (JEDEC_ID=%08x)!\n", jedec_id); return; } dev_info(&spi->dev, "FPGA %s detected\n", ecp3_dev[i].name); txbuf[0] = FPGA_CMD_READ_STATUS; ret = spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len); dev_dbg(&spi->dev, "FPGA Status=%08x\n", *(u32 *)&rxbuf[4]); buffer = kzalloc(fw->size + 8, GFP_KERNEL); if (!buffer) { dev_err(&spi->dev, "Error: Can't allocate memory!\n"); return; } /* * Insert WRITE_INC command into stream (one SPI frame) */ buffer[0] = FPGA_CMD_WRITE_INC; buffer[1] = 0xff; buffer[2] = 0xff; buffer[3] = 0xff; memcpy(buffer + 4, fw->data, fw->size); txbuf[0] = FPGA_CMD_REFRESH; ret = spi_write(spi, txbuf, 4); txbuf[0] = FPGA_CMD_WRITE_EN; ret = spi_write(spi, txbuf, 4); txbuf[0] = FPGA_CMD_CLEAR; ret = spi_write(spi, txbuf, 4); /* * Wait for FPGA memory to become cleared */ for (i = 0; i < FPGA_CLEAR_LOOP_COUNT; i++) { txbuf[0] = FPGA_CMD_READ_STATUS; ret = spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len); status = *(u32 *)&rxbuf[4]; if (status == FPGA_STATUS_CLEARED) break; msleep(FPGA_CLEAR_MSLEEP); } if (i == FPGA_CLEAR_LOOP_COUNT) { dev_err(&spi->dev, "Error: Timeout waiting for FPGA to clear (status=%08x)!\n", status); kfree(buffer); return; } dev_info(&spi->dev, "Configuring the FPGA...\n"); ret = spi_write(spi, buffer, fw->size + 8); txbuf[0] = FPGA_CMD_WRITE_DIS; ret = spi_write(spi, txbuf, 4); txbuf[0] = FPGA_CMD_READ_STATUS; ret = spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len); dev_dbg(&spi->dev, "FPGA Status=%08x\n", *(u32 *)&rxbuf[4]); status = *(u32 *)&rxbuf[4]; /* Check result */ if (status & FPGA_STATUS_DONE) dev_info(&spi->dev, "FPGA succesfully configured!\n"); else dev_info(&spi->dev, "FPGA not configured (DONE not set)\n"); /* * Don't forget to release the firmware again */ release_firmware(fw); kfree(buffer); complete(&data->fw_loaded); } static int lattice_ecp3_probe(struct spi_device *spi) { struct fpga_data *data; int err; data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL); if (!data) { dev_err(&spi->dev, "Memory allocation for fpga_data failed\n"); return -ENOMEM; } spi_set_drvdata(spi, data); init_completion(&data->fw_loaded); err = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOHOTPLUG, FIRMWARE_NAME, &spi->dev, GFP_KERNEL, spi, firmware_load); if (err) { dev_err(&spi->dev, "Firmware loading failed with %d!\n", err); return err; } dev_info(&spi->dev, "FPGA bitstream configuration driver registered\n"); return 0; } static int lattice_ecp3_remove(struct spi_device *spi) { struct fpga_data *data = spi_get_drvdata(spi); wait_for_completion(&data->fw_loaded); return 0; } static const struct spi_device_id lattice_ecp3_id[] = { { "ecp3-17", 0 }, { "ecp3-35", 0 }, { } }; MODULE_DEVICE_TABLE(spi, lattice_ecp3_id); static struct spi_driver lattice_ecp3_driver = { .driver = { .name = "lattice-ecp3", .owner = THIS_MODULE, }, .probe = lattice_ecp3_probe, .remove = lattice_ecp3_remove, .id_table = lattice_ecp3_id, }; module_spi_driver(lattice_ecp3_driver); MODULE_AUTHOR("Stefan Roese <sr@denx.de>"); MODULE_DESCRIPTION("Lattice ECP3 FPGA configuration via SPI"); MODULE_LICENSE("GPL");