1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Xilinx Spartan6 and 7 Series Slave Serial SPI Driver
 4 *
 5 * Copyright (C) 2017 DENX Software Engineering
 6 *
 7 * Anatolij Gustschin <agust@denx.de>
 8 *
 9 * Manage Xilinx FPGA firmware that is loaded over SPI using
10 * the slave serial configuration interface.
11 */
12
13#include "xilinx-core.h"
14
15#include <linux/module.h>
16#include <linux/mod_devicetable.h>
17#include <linux/of.h>
18#include <linux/spi/spi.h>
19
20static int xilinx_spi_write(struct xilinx_fpga_core *core, const char *buf,
21			    size_t count)
22{
23	struct spi_device *spi = to_spi_device(core->dev);
24	const char *fw_data = buf;
25	const char *fw_data_end = fw_data + count;
26
27	while (fw_data < fw_data_end) {
28		size_t remaining, stride;
29		int ret;
30
31		remaining = fw_data_end - fw_data;
32		stride = min_t(size_t, remaining, SZ_4K);
33
34		ret = spi_write(spi, fw_data, stride);
35		if (ret) {
36			dev_err(core->dev, "SPI error in firmware write: %d\n",
37				ret);
38			return ret;
39		}
40		fw_data += stride;
41	}
42
43	return 0;
44}
45
46static int xilinx_spi_probe(struct spi_device *spi)
47{
48	struct xilinx_fpga_core *core;
49
50	core = devm_kzalloc(&spi->dev, sizeof(*core), GFP_KERNEL);
51	if (!core)
52		return -ENOMEM;
53
54	core->dev = &spi->dev;
55	core->write = xilinx_spi_write;
56
57	return xilinx_core_probe(core);
58}
59
60#ifdef CONFIG_OF
61static const struct of_device_id xlnx_spi_of_match[] = {
62	{
63		.compatible = "xlnx,fpga-slave-serial",
64	},
65	{}
66};
67MODULE_DEVICE_TABLE(of, xlnx_spi_of_match);
68#endif
69
70static struct spi_driver xilinx_slave_spi_driver = {
71	.driver = {
72		.name = "xlnx-slave-spi",
73		.of_match_table = of_match_ptr(xlnx_spi_of_match),
74	},
75	.probe = xilinx_spi_probe,
76};
77
78module_spi_driver(xilinx_slave_spi_driver)
79
80MODULE_LICENSE("GPL v2");
81MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>");
82MODULE_DESCRIPTION("Load Xilinx FPGA firmware over SPI");