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![Moritz Fischer](/assets/img/avatar_default.png)
Simplify registration using new devm_fpga_mgr_register() API. Reviewed-by: Tom Rix <trix@redhat.com> Signed-off-by: Moritz Fischer <mdf@kernel.org> Link: https://lore.kernel.org/r/20201115195127.284487-5-mdf@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
207 lines
5.2 KiB
C
207 lines
5.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* FPGA Manager Driver for Lattice iCE40.
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*
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* Copyright (c) 2016 Joel Holdsworth
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*
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* This driver adds support to the FPGA manager for configuring the SRAM of
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* Lattice iCE40 FPGAs through slave SPI.
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*/
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#include <linux/fpga/fpga-mgr.h>
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#include <linux/gpio/consumer.h>
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#include <linux/module.h>
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#include <linux/of_gpio.h>
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#include <linux/spi/spi.h>
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#include <linux/stringify.h>
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#define ICE40_SPI_MAX_SPEED 25000000 /* Hz */
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#define ICE40_SPI_MIN_SPEED 1000000 /* Hz */
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#define ICE40_SPI_RESET_DELAY 1 /* us (>200ns) */
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#define ICE40_SPI_HOUSEKEEPING_DELAY 1200 /* us */
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#define ICE40_SPI_NUM_ACTIVATION_BYTES DIV_ROUND_UP(49, 8)
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struct ice40_fpga_priv {
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struct spi_device *dev;
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struct gpio_desc *reset;
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struct gpio_desc *cdone;
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};
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static enum fpga_mgr_states ice40_fpga_ops_state(struct fpga_manager *mgr)
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{
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struct ice40_fpga_priv *priv = mgr->priv;
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return gpiod_get_value(priv->cdone) ? FPGA_MGR_STATE_OPERATING :
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FPGA_MGR_STATE_UNKNOWN;
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}
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static int ice40_fpga_ops_write_init(struct fpga_manager *mgr,
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struct fpga_image_info *info,
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const char *buf, size_t count)
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{
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struct ice40_fpga_priv *priv = mgr->priv;
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struct spi_device *dev = priv->dev;
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struct spi_message message;
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struct spi_transfer assert_cs_then_reset_delay = {
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.cs_change = 1,
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.delay = {
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.value = ICE40_SPI_RESET_DELAY,
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.unit = SPI_DELAY_UNIT_USECS
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}
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};
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struct spi_transfer housekeeping_delay_then_release_cs = {
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.delay = {
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.value = ICE40_SPI_HOUSEKEEPING_DELAY,
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.unit = SPI_DELAY_UNIT_USECS
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}
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};
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int ret;
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if ((info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
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dev_err(&dev->dev,
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"Partial reconfiguration is not supported\n");
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return -ENOTSUPP;
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}
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/* Lock the bus, assert CRESET_B and SS_B and delay >200ns */
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spi_bus_lock(dev->master);
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gpiod_set_value(priv->reset, 1);
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spi_message_init(&message);
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spi_message_add_tail(&assert_cs_then_reset_delay, &message);
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ret = spi_sync_locked(dev, &message);
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/* Come out of reset */
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gpiod_set_value(priv->reset, 0);
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/* Abort if the chip-select failed */
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if (ret)
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goto fail;
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/* Check CDONE is de-asserted i.e. the FPGA is reset */
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if (gpiod_get_value(priv->cdone)) {
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dev_err(&dev->dev, "Device reset failed, CDONE is asserted\n");
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ret = -EIO;
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goto fail;
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}
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/* Wait for the housekeeping to complete, and release SS_B */
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spi_message_init(&message);
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spi_message_add_tail(&housekeeping_delay_then_release_cs, &message);
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ret = spi_sync_locked(dev, &message);
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fail:
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spi_bus_unlock(dev->master);
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return ret;
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}
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static int ice40_fpga_ops_write(struct fpga_manager *mgr,
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const char *buf, size_t count)
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{
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struct ice40_fpga_priv *priv = mgr->priv;
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return spi_write(priv->dev, buf, count);
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}
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static int ice40_fpga_ops_write_complete(struct fpga_manager *mgr,
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struct fpga_image_info *info)
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{
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struct ice40_fpga_priv *priv = mgr->priv;
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struct spi_device *dev = priv->dev;
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const u8 padding[ICE40_SPI_NUM_ACTIVATION_BYTES] = {0};
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/* Check CDONE is asserted */
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if (!gpiod_get_value(priv->cdone)) {
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dev_err(&dev->dev,
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"CDONE was not asserted after firmware transfer\n");
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return -EIO;
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}
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/* Send of zero-padding to activate the firmware */
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return spi_write(dev, padding, sizeof(padding));
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}
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static const struct fpga_manager_ops ice40_fpga_ops = {
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.state = ice40_fpga_ops_state,
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.write_init = ice40_fpga_ops_write_init,
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.write = ice40_fpga_ops_write,
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.write_complete = ice40_fpga_ops_write_complete,
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};
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static int ice40_fpga_probe(struct spi_device *spi)
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{
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struct device *dev = &spi->dev;
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struct ice40_fpga_priv *priv;
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struct fpga_manager *mgr;
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int ret;
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priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->dev = spi;
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/* Check board setup data. */
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if (spi->max_speed_hz > ICE40_SPI_MAX_SPEED) {
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dev_err(dev, "SPI speed is too high, maximum speed is "
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__stringify(ICE40_SPI_MAX_SPEED) "\n");
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return -EINVAL;
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}
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if (spi->max_speed_hz < ICE40_SPI_MIN_SPEED) {
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dev_err(dev, "SPI speed is too low, minimum speed is "
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__stringify(ICE40_SPI_MIN_SPEED) "\n");
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return -EINVAL;
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}
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if (spi->mode & SPI_CPHA) {
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dev_err(dev, "Bad SPI mode, CPHA not supported\n");
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return -EINVAL;
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}
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/* Set up the GPIOs */
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priv->cdone = devm_gpiod_get(dev, "cdone", GPIOD_IN);
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if (IS_ERR(priv->cdone)) {
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ret = PTR_ERR(priv->cdone);
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dev_err(dev, "Failed to get CDONE GPIO: %d\n", ret);
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return ret;
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}
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priv->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
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if (IS_ERR(priv->reset)) {
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ret = PTR_ERR(priv->reset);
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dev_err(dev, "Failed to get CRESET_B GPIO: %d\n", ret);
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return ret;
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}
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mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
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&ice40_fpga_ops, priv);
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if (!mgr)
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return -ENOMEM;
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return devm_fpga_mgr_register(dev, mgr);
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}
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static const struct of_device_id ice40_fpga_of_match[] = {
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{ .compatible = "lattice,ice40-fpga-mgr", },
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{},
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};
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MODULE_DEVICE_TABLE(of, ice40_fpga_of_match);
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static struct spi_driver ice40_fpga_driver = {
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.probe = ice40_fpga_probe,
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.driver = {
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.name = "ice40spi",
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.of_match_table = of_match_ptr(ice40_fpga_of_match),
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},
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};
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module_spi_driver(ice40_fpga_driver);
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MODULE_AUTHOR("Joel Holdsworth <joel@airwebreathe.org.uk>");
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MODULE_DESCRIPTION("Lattice iCE40 FPGA Manager");
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MODULE_LICENSE("GPL v2");
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