--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Common parts of the Xilinx Spartan6 and 7 Series FPGA manager drivers.
+ *
+ * Copyright (C) 2017 DENX Software Engineering
+ *
+ * Anatolij Gustschin <agust@denx.de>
+ */
+
+#include "xilinx-core.h"
+
+#include <linux/delay.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/gpio/consumer.h>
+#include <linux/of.h>
+
+static int get_done_gpio(struct fpga_manager *mgr)
+{
+ struct xilinx_fpga_core *core = mgr->priv;
+ int ret;
+
+ ret = gpiod_get_value(core->done);
+ if (ret < 0)
+ dev_err(&mgr->dev, "Error reading DONE (%d)\n", ret);
+
+ return ret;
+}
+
+static enum fpga_mgr_states xilinx_core_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_fpga_core *core = mgr->priv;
+ unsigned long timeout = jiffies + msecs_to_jiffies(1000);
+
+ if (core->init_b) {
+ while (time_before(jiffies, timeout)) {
+ int ret = gpiod_get_value(core->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_core_write_init(struct fpga_manager *mgr,
+ struct fpga_image_info *info, const char *buf,
+ size_t count)
+{
+ struct xilinx_fpga_core *core = 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(core->prog_b, 1);
+
+ err = wait_for_init_b(mgr, 1, 1); /* min is 500 ns */
+ if (err) {
+ gpiod_set_value(core->prog_b, 0);
+ return err;
+ }
+
+ gpiod_set_value(core->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_core_write(struct fpga_manager *mgr, const char *buf,
+ size_t count)
+{
+ struct xilinx_fpga_core *core = mgr->priv;
+
+ return core->write(core, buf, count);
+}
+
+static int xilinx_core_write_complete(struct fpga_manager *mgr,
+ struct fpga_image_info *info)
+{
+ struct xilinx_fpga_core *core = mgr->priv;
+ unsigned long timeout =
+ jiffies + usecs_to_jiffies(info->config_complete_timeout_us);
+ bool expired = false;
+ int done;
+ int ret;
+ const char padding[1] = { 0xff };
+
+ /*
+ * 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 = core->write(core, padding, sizeof(padding));
+ if (ret)
+ return ret;
+
+ if (done)
+ return 0;
+ }
+
+ if (core->init_b) {
+ ret = gpiod_get_value(core->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_core_ops = {
+ .state = xilinx_core_state,
+ .write_init = xilinx_core_write_init,
+ .write = xilinx_core_write,
+ .write_complete = xilinx_core_write_complete,
+};
+
+int xilinx_core_probe(struct xilinx_fpga_core *core)
+{
+ struct fpga_manager *mgr;
+
+ if (!core || !core->dev || !core->write)
+ return -EINVAL;
+
+ /* PROGRAM_B is active low */
+ core->prog_b = devm_gpiod_get(core->dev, "prog_b", GPIOD_OUT_LOW);
+ if (IS_ERR(core->prog_b))
+ return dev_err_probe(core->dev, PTR_ERR(core->prog_b),
+ "Failed to get PROGRAM_B gpio\n");
+
+ core->init_b = devm_gpiod_get_optional(core->dev, "init-b", GPIOD_IN);
+ if (IS_ERR(core->init_b))
+ return dev_err_probe(core->dev, PTR_ERR(core->init_b),
+ "Failed to get INIT_B gpio\n");
+
+ core->done = devm_gpiod_get(core->dev, "done", GPIOD_IN);
+ if (IS_ERR(core->done))
+ return dev_err_probe(core->dev, PTR_ERR(core->done),
+ "Failed to get DONE gpio\n");
+
+ mgr = devm_fpga_mgr_register(core->dev,
+ "Xilinx Slave Serial FPGA Manager",
+ &xilinx_core_ops, core);
+ return PTR_ERR_OR_ZERO(mgr);
+}
+EXPORT_SYMBOL_GPL(xilinx_core_probe);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>");
+MODULE_DESCRIPTION("Xilinx 7 Series FPGA manager core");
projects / linux-block.git / blobdiff