xref: /linux/drivers/fpga/xilinx-spi.c (revision da5b2ad1c2f18834cb1ce429e2e5a5cf5cbdf21b)
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 
20 static 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 
46 static 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
61 static const struct of_device_id xlnx_spi_of_match[] = {
62 	{
63 		.compatible = "xlnx,fpga-slave-serial",
64 	},
65 	{}
66 };
67 MODULE_DEVICE_TABLE(of, xlnx_spi_of_match);
68 #endif
69 
70 static 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 
78 module_spi_driver(xilinx_slave_spi_driver)
79 
80 MODULE_LICENSE("GPL v2");
81 MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>");
82 MODULE_DESCRIPTION("Load Xilinx FPGA firmware over SPI");
83