linux/drivers/fpga/xilinx-spi.c
Charles Perry a52e3a9dba
fpga: xilinx-spi: extract a common driver core
Factor out the gpio handshaking (using PROGRAM_B, INIT_B and DONE)
protocol in xilinx-core so that it can be reused for another driver.
This commit does not change anything functionally to xilinx-spi.

xilinx-core expects drivers to provide a write(const char* buf,
size_t count) function that performs the actual write to the device,
as well as a struct device* for resource management.

Signed-off-by: Charles Perry <charles.perry@savoirfairelinux.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20240321220447.3260065-2-charles.perry@savoirfairelinux.com
Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
2024-03-31 22:41:26 +08:00

83 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Xilinx Spartan6 and 7 Series Slave Serial SPI Driver
*
* Copyright (C) 2017 DENX Software Engineering
*
* Anatolij Gustschin <agust@denx.de>
*
* Manage Xilinx FPGA firmware that is loaded over SPI using
* the slave serial configuration interface.
*/
#include "xilinx-core.h"
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/of.h>
#include <linux/spi/spi.h>
static int xilinx_spi_write(struct xilinx_fpga_core *core, const char *buf,
size_t count)
{
struct spi_device *spi = to_spi_device(core->dev);
const char *fw_data = buf;
const char *fw_data_end = fw_data + count;
while (fw_data < fw_data_end) {
size_t remaining, stride;
int ret;
remaining = fw_data_end - fw_data;
stride = min_t(size_t, remaining, SZ_4K);
ret = spi_write(spi, fw_data, stride);
if (ret) {
dev_err(core->dev, "SPI error in firmware write: %d\n",
ret);
return ret;
}
fw_data += stride;
}
return 0;
}
static int xilinx_spi_probe(struct spi_device *spi)
{
struct xilinx_fpga_core *core;
core = devm_kzalloc(&spi->dev, sizeof(*core), GFP_KERNEL);
if (!core)
return -ENOMEM;
core->dev = &spi->dev;
core->write = xilinx_spi_write;
return xilinx_core_probe(core);
}
#ifdef CONFIG_OF
static const struct of_device_id xlnx_spi_of_match[] = {
{
.compatible = "xlnx,fpga-slave-serial",
},
{}
};
MODULE_DEVICE_TABLE(of, xlnx_spi_of_match);
#endif
static struct spi_driver xilinx_slave_spi_driver = {
.driver = {
.name = "xlnx-slave-spi",
.of_match_table = of_match_ptr(xlnx_spi_of_match),
},
.probe = xilinx_spi_probe,
};
module_spi_driver(xilinx_slave_spi_driver)
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>");
MODULE_DESCRIPTION("Load Xilinx FPGA firmware over SPI");