From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/fpga/xilinx-spi.c | 276 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 276 insertions(+) create mode 100644 drivers/fpga/xilinx-spi.c (limited to 'drivers/fpga/xilinx-spi.c') diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c new file mode 100644 index 0000000000..e1a227e7ff --- /dev/null +++ b/drivers/fpga/xilinx-spi.c @@ -0,0 +1,276 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Xilinx Spartan6 and 7 Series Slave Serial SPI Driver + * + * Copyright (C) 2017 DENX Software Engineering + * + * Anatolij Gustschin + * + * Manage Xilinx FPGA firmware that is loaded over SPI using + * the slave serial configuration interface. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct xilinx_spi_conf { + struct spi_device *spi; + struct gpio_desc *prog_b; + struct gpio_desc *init_b; + struct gpio_desc *done; +}; + +static int get_done_gpio(struct fpga_manager *mgr) +{ + struct xilinx_spi_conf *conf = mgr->priv; + int ret; + + ret = gpiod_get_value(conf->done); + + if (ret < 0) + dev_err(&mgr->dev, "Error reading DONE (%d)\n", ret); + + return ret; +} + +static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr) +{ + if (!get_done_gpio(mgr)) + return FPGA_MGR_STATE_RESET; + + return FPGA_MGR_STATE_UNKNOWN; +} + +/** + * wait_for_init_b - wait for the INIT_B pin to have a given state, or wait + * a given delay if the pin is unavailable + * + * @mgr: The FPGA manager object + * @value: Value INIT_B to wait for (1 = asserted = low) + * @alt_udelay: Delay to wait if the INIT_B GPIO is not available + * + * Returns 0 when the INIT_B GPIO reached the given state or -ETIMEDOUT if + * too much time passed waiting for that. If no INIT_B GPIO is available + * then always return 0. + */ +static int wait_for_init_b(struct fpga_manager *mgr, int value, + unsigned long alt_udelay) +{ + struct xilinx_spi_conf *conf = mgr->priv; + unsigned long timeout = jiffies + msecs_to_jiffies(1000); + + if (conf->init_b) { + while (time_before(jiffies, timeout)) { + int ret = gpiod_get_value(conf->init_b); + + if (ret == value) + return 0; + + if (ret < 0) { + dev_err(&mgr->dev, "Error reading INIT_B (%d)\n", ret); + return ret; + } + + usleep_range(100, 400); + } + + dev_err(&mgr->dev, "Timeout waiting for INIT_B to %s\n", + value ? "assert" : "deassert"); + return -ETIMEDOUT; + } + + udelay(alt_udelay); + + return 0; +} + +static int xilinx_spi_write_init(struct fpga_manager *mgr, + struct fpga_image_info *info, + const char *buf, size_t count) +{ + struct xilinx_spi_conf *conf = mgr->priv; + int err; + + if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) { + dev_err(&mgr->dev, "Partial reconfiguration not supported\n"); + return -EINVAL; + } + + gpiod_set_value(conf->prog_b, 1); + + err = wait_for_init_b(mgr, 1, 1); /* min is 500 ns */ + if (err) { + gpiod_set_value(conf->prog_b, 0); + return err; + } + + gpiod_set_value(conf->prog_b, 0); + + err = wait_for_init_b(mgr, 0, 0); + if (err) + return err; + + if (get_done_gpio(mgr)) { + dev_err(&mgr->dev, "Unexpected DONE pin state...\n"); + return -EIO; + } + + /* program latency */ + usleep_range(7500, 7600); + return 0; +} + +static int xilinx_spi_write(struct fpga_manager *mgr, const char *buf, + size_t count) +{ + struct xilinx_spi_conf *conf = mgr->priv; + const char *fw_data = buf; + const char *fw_data_end = fw_data + count; + + while (fw_data < fw_data_end) { + size_t remaining, stride; + int ret; + + remaining = fw_data_end - fw_data; + stride = min_t(size_t, remaining, SZ_4K); + + 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 xilinx_spi_apply_cclk_cycles(struct xilinx_spi_conf *conf) +{ + struct spi_device *spi = conf->spi; + const u8 din_data[1] = { 0xff }; + int ret; + + ret = spi_write(conf->spi, din_data, sizeof(din_data)); + if (ret) + dev_err(&spi->dev, "applying CCLK cycles failed: %d\n", ret); + + return ret; +} + +static int xilinx_spi_write_complete(struct fpga_manager *mgr, + struct fpga_image_info *info) +{ + struct xilinx_spi_conf *conf = mgr->priv; + unsigned long timeout = jiffies + usecs_to_jiffies(info->config_complete_timeout_us); + bool expired = false; + int done; + int ret; + + /* + * This loop is carefully written such that if the driver is + * scheduled out for more than 'timeout', we still check for DONE + * before giving up and we apply 8 extra CCLK cycles in all cases. + */ + while (!expired) { + expired = time_after(jiffies, timeout); + + done = get_done_gpio(mgr); + if (done < 0) + return done; + + ret = xilinx_spi_apply_cclk_cycles(conf); + if (ret) + return ret; + + if (done) + return 0; + } + + if (conf->init_b) { + ret = gpiod_get_value(conf->init_b); + + if (ret < 0) { + dev_err(&mgr->dev, "Error reading INIT_B (%d)\n", ret); + return ret; + } + + dev_err(&mgr->dev, + ret ? "CRC error or invalid device\n" + : "Missing sync word or incomplete bitstream\n"); + } else { + dev_err(&mgr->dev, "Timeout after config data transfer\n"); + } + + return -ETIMEDOUT; +} + +static const struct fpga_manager_ops xilinx_spi_ops = { + .state = xilinx_spi_state, + .write_init = xilinx_spi_write_init, + .write = xilinx_spi_write, + .write_complete = xilinx_spi_write_complete, +}; + +static int xilinx_spi_probe(struct spi_device *spi) +{ + struct xilinx_spi_conf *conf; + struct fpga_manager *mgr; + + conf = devm_kzalloc(&spi->dev, sizeof(*conf), GFP_KERNEL); + if (!conf) + return -ENOMEM; + + conf->spi = spi; + + /* PROGRAM_B is active low */ + conf->prog_b = devm_gpiod_get(&spi->dev, "prog_b", GPIOD_OUT_LOW); + if (IS_ERR(conf->prog_b)) + return dev_err_probe(&spi->dev, PTR_ERR(conf->prog_b), + "Failed to get PROGRAM_B gpio\n"); + + conf->init_b = devm_gpiod_get_optional(&spi->dev, "init-b", GPIOD_IN); + if (IS_ERR(conf->init_b)) + return dev_err_probe(&spi->dev, PTR_ERR(conf->init_b), + "Failed to get INIT_B gpio\n"); + + conf->done = devm_gpiod_get(&spi->dev, "done", GPIOD_IN); + if (IS_ERR(conf->done)) + return dev_err_probe(&spi->dev, PTR_ERR(conf->done), + "Failed to get DONE gpio\n"); + + mgr = devm_fpga_mgr_register(&spi->dev, + "Xilinx Slave Serial FPGA Manager", + &xilinx_spi_ops, conf); + return PTR_ERR_OR_ZERO(mgr); +} + +#ifdef CONFIG_OF +static const struct of_device_id xlnx_spi_of_match[] = { + { .compatible = "xlnx,fpga-slave-serial", }, + {} +}; +MODULE_DEVICE_TABLE(of, xlnx_spi_of_match); +#endif + +static struct spi_driver xilinx_slave_spi_driver = { + .driver = { + .name = "xlnx-slave-spi", + .of_match_table = of_match_ptr(xlnx_spi_of_match), + }, + .probe = xilinx_spi_probe, +}; + +module_spi_driver(xilinx_slave_spi_driver) + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Anatolij Gustschin "); +MODULE_DESCRIPTION("Load Xilinx FPGA firmware over SPI"); -- cgit v1.2.3