diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/fpga/xilinx-spi.c | 55 |
1 files changed, 54 insertions, 1 deletions
diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c index 799ae04301be..2967aa2a74e2 100644 --- a/drivers/fpga/xilinx-spi.c +++ b/drivers/fpga/xilinx-spi.c @@ -23,6 +23,7 @@ struct xilinx_spi_conf { struct spi_device *spi; struct gpio_desc *prog_b; + struct gpio_desc *init_b; struct gpio_desc *done; }; @@ -36,11 +37,45 @@ static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr) 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)) { + /* dump_state(conf, "wait for init_d .."); */ + if (gpiod_get_value(conf->init_b) == value) + return 0; + usleep_range(100, 400); + } + 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"); @@ -49,10 +84,21 @@ static int xilinx_spi_write_init(struct fpga_manager *mgr, gpiod_set_value(conf->prog_b, 1); - udelay(1); /* min is 500 ns */ + err = wait_for_init_b(mgr, 1, 1); /* min is 500 ns */ + if (err) { + dev_err(&mgr->dev, "INIT_B pin did not go low\n"); + 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) { + dev_err(&mgr->dev, "INIT_B pin did not go high\n"); + return err; + } + if (gpiod_get_value(conf->done)) { dev_err(&mgr->dev, "Unexpected DONE pin state...\n"); return -EIO; @@ -154,6 +200,13 @@ static int xilinx_spi_probe(struct spi_device *spi) return PTR_ERR(conf->prog_b); } + conf->init_b = devm_gpiod_get_optional(&spi->dev, "init-b", GPIOD_IN); + if (IS_ERR(conf->init_b)) { + dev_err(&spi->dev, "Failed to get INIT_B gpio: %ld\n", + PTR_ERR(conf->init_b)); + return PTR_ERR(conf->init_b); + } + conf->done = devm_gpiod_get(&spi->dev, "done", GPIOD_IN); if (IS_ERR(conf->done)) { dev_err(&spi->dev, "Failed to get DONE gpio: %ld\n", |