src/kernel/linux/v4.19/drivers/spi/spi-cavium-octeon.c

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2011, 2012 Cavium, Inc.
 */

#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/of.h>

#include <asm/octeon/octeon.h>

#include "spi-cavium.h"

static int octeon_spi_probe(struct platform_device *pdev)
{
	struct resource *res_mem;
	void __iomem *reg_base;
	struct spi_master *master;
	struct octeon_spi *p;
	int err = -ENOENT;

	master = spi_alloc_master(&pdev->dev, sizeof(struct octeon_spi));
	if (!master)
		return -ENOMEM;
	p = spi_master_get_devdata(master);
	platform_set_drvdata(pdev, master);

	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	reg_base = devm_ioremap_resource(&pdev->dev, res_mem);
	if (IS_ERR(reg_base)) {
		err = PTR_ERR(reg_base);
		goto fail;
	}

	p->register_base = reg_base;
	p->sys_freq = octeon_get_io_clock_rate();

	p->regs.config = 0;
	p->regs.status = 0x08;
	p->regs.tx = 0x10;
	p->regs.data = 0x80;

	master->num_chipselect = 4;
	master->mode_bits = SPI_CPHA |
			    SPI_CPOL |
			    SPI_CS_HIGH |
			    SPI_LSB_FIRST |
			    SPI_3WIRE;

	master->transfer_one_message = octeon_spi_transfer_one_message;
	master->bits_per_word_mask = SPI_BPW_MASK(8);
	master->max_speed_hz = OCTEON_SPI_MAX_CLOCK_HZ;

	master->dev.of_node = pdev->dev.of_node;
	err = devm_spi_register_master(&pdev->dev, master);
	if (err) {
		dev_err(&pdev->dev, "register master failed: %d\n", err);
		goto fail;
	}

	dev_info(&pdev->dev, "OCTEON SPI bus driver\n");

	return 0;
fail:
	spi_master_put(master);
	return err;
}

static int octeon_spi_remove(struct platform_device *pdev)
{
	struct spi_master *master = platform_get_drvdata(pdev);
	struct octeon_spi *p = spi_master_get_devdata(master);

	/* Clear the CSENA* and put everything in a known state. */
	writeq(0, p->register_base + OCTEON_SPI_CFG(p));

	return 0;
}

static const struct of_device_id octeon_spi_match[] = {
	{ .compatible = "cavium,octeon-3010-spi", },
	{},
};
MODULE_DEVICE_TABLE(of, octeon_spi_match);

static struct platform_driver octeon_spi_driver = {
	.driver = {
		.name		= "spi-octeon",
		.of_match_table = octeon_spi_match,
	},
	.probe		= octeon_spi_probe,
	.remove		= octeon_spi_remove,
};

module_platform_driver(octeon_spi_driver);

MODULE_DESCRIPTION("Cavium, Inc. OCTEON SPI bus driver");
MODULE_AUTHOR("David Daney");
MODULE_LICENSE("GPL");