From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/drivers/fpga/xilinx-spi.c | 157 +++++++++++++++++++++++++++++++++++++++-------------
1 files changed, 117 insertions(+), 40 deletions(-)
diff --git a/kernel/drivers/fpga/xilinx-spi.c b/kernel/drivers/fpga/xilinx-spi.c
index 8d19459..d3e6f41 100644
--- a/kernel/drivers/fpga/xilinx-spi.c
+++ b/kernel/drivers/fpga/xilinx-spi.c
@@ -1,13 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
- * Xilinx Spartan6 Slave Serial SPI Driver
+ * Xilinx Spartan6 and 7 Series Slave Serial SPI Driver
*
* Copyright (C) 2017 DENX Software Engineering
*
* Anatolij Gustschin <agust@denx.de>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
*
* Manage Xilinx FPGA firmware that is loaded over SPI using
* the slave serial configuration interface.
@@ -26,17 +23,72 @@
struct xilinx_spi_conf {
struct spi_device *spi;
struct gpio_desc *prog_b;
+ struct gpio_desc *init_b;
struct gpio_desc *done;
};
-static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr)
+static int get_done_gpio(struct fpga_manager *mgr)
{
struct xilinx_spi_conf *conf = mgr->priv;
+ int ret;
- if (!gpiod_get_value(conf->done))
+ 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,
@@ -44,27 +96,34 @@
const char *buf, size_t count)
{
struct xilinx_spi_conf *conf = mgr->priv;
- const size_t prog_latency_7500us = 7500;
- const size_t prog_pulse_1us = 1;
+ int err;
if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
- dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
+ dev_err(&mgr->dev, "Partial reconfiguration not supported\n");
return -EINVAL;
}
gpiod_set_value(conf->prog_b, 1);
- udelay(prog_pulse_1us); /* min is 500 ns */
+ 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);
- if (gpiod_get_value(conf->done)) {
+ 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(prog_latency_7500us, prog_latency_7500us + 100);
+ usleep_range(7500, 7600);
return 0;
}
@@ -111,25 +170,46 @@
struct fpga_image_info *info)
{
struct xilinx_spi_conf *conf = mgr->priv;
- unsigned long timeout;
+ unsigned long timeout = jiffies + usecs_to_jiffies(info->config_complete_timeout_us);
+ bool expired = false;
+ int done;
int ret;
- if (gpiod_get_value(conf->done))
- return xilinx_spi_apply_cclk_cycles(conf);
+ /*
+ * 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);
- timeout = jiffies + usecs_to_jiffies(info->config_complete_timeout_us);
-
- while (time_before(jiffies, timeout)) {
+ done = get_done_gpio(mgr);
+ if (done < 0)
+ return done;
ret = xilinx_spi_apply_cclk_cycles(conf);
if (ret)
return ret;
- if (gpiod_get_value(conf->done))
- return xilinx_spi_apply_cclk_cycles(conf);
+ if (done)
+ return 0;
}
- dev_err(&mgr->dev, "Timeout after config data transfer.\n");
+ 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;
}
@@ -144,7 +224,6 @@
{
struct xilinx_spi_conf *conf;
struct fpga_manager *mgr;
- int ret;
conf = devm_kzalloc(&spi->dev, sizeof(*conf), GFP_KERNEL);
if (!conf)
@@ -154,31 +233,29 @@
/* PROGRAM_B is active low */
conf->prog_b = devm_gpiod_get(&spi->dev, "prog_b", GPIOD_OUT_LOW);
- if (IS_ERR(conf->prog_b)) {
- dev_err(&spi->dev, "Failed to get PROGRAM_B gpio: %ld\n",
- PTR_ERR(conf->prog_b));
- return PTR_ERR(conf->prog_b);
- }
+ 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)) {
- dev_err(&spi->dev, "Failed to get DONE gpio: %ld\n",
- PTR_ERR(conf->done));
- return PTR_ERR(conf->done);
- }
+ if (IS_ERR(conf->done))
+ return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
+ "Failed to get DONE gpio\n");
- mgr = fpga_mgr_create(&spi->dev, "Xilinx Slave Serial FPGA Manager",
- &xilinx_spi_ops, conf);
+ mgr = devm_fpga_mgr_create(&spi->dev,
+ "Xilinx Slave Serial FPGA Manager",
+ &xilinx_spi_ops, conf);
if (!mgr)
return -ENOMEM;
spi_set_drvdata(spi, mgr);
- ret = fpga_mgr_register(mgr);
- if (ret)
- fpga_mgr_free(mgr);
-
- return ret;
+ return fpga_mgr_register(mgr);
}
static int xilinx_spi_remove(struct spi_device *spi)
--
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