linux/drivers/spi/spi-fsl-lib.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Freescale SPI/eSPI controller driver library.
 *
 * Maintainer: Kumar Gala
 *
 * Copyright (C) 2006 Polycom, Inc.
 *
 * CPM SPI and QE buffer descriptors mode support:
 * Copyright (c) 2009  MontaVista Software, Inc.
 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
 *
 * Copyright 2010 Freescale Semiconductor, Inc.
 */
#include <linux/dma-mapping.h>
#include <linux/fsl_devices.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/spi/spi.h>
#ifdef CONFIG_FSL_SOC
#include <sysdev/fsl_soc.h>
#endif

#include "spi-fsl-lib.h"

#define MPC8XXX_SPI_RX_BUF(type) 					  \
void mpc8xxx_spi_rx_buf_##type(u32 data, struct mpc8xxx_spi *mpc8xxx_spi) \
{									  \
	type *rx = mpc8xxx_spi->rx;					  \
	*rx++ = (type)(data >> mpc8xxx_spi->rx_shift);			  \
	mpc8xxx_spi->rx = rx;						  \
}									  \
EXPORT_SYMBOL_GPL(mpc8xxx_spi_rx_buf_##type);

#define MPC8XXX_SPI_TX_BUF(type)				\
u32 mpc8xxx_spi_tx_buf_##type(struct mpc8xxx_spi *mpc8xxx_spi)	\
{								\
	u32 data;						\
	const type *tx = mpc8xxx_spi->tx;			\
	if (!tx)						\
		return 0;					\
	data = *tx++ << mpc8xxx_spi->tx_shift;			\
	mpc8xxx_spi->tx = tx;					\
	return data;						\
}								\
EXPORT_SYMBOL_GPL(mpc8xxx_spi_tx_buf_##type);

MPC8XXX_SPI_RX_BUF(u8)
MPC8XXX_SPI_RX_BUF(u16)
MPC8XXX_SPI_RX_BUF(u32)
MPC8XXX_SPI_TX_BUF(u8)
MPC8XXX_SPI_TX_BUF(u16)
MPC8XXX_SPI_TX_BUF(u32)

struct mpc8xxx_spi_probe_info *to_of_pinfo(struct fsl_spi_platform_data *pdata)
{
	return container_of(pdata, struct mpc8xxx_spi_probe_info, pdata);
}
EXPORT_SYMBOL_GPL(to_of_pinfo);

const char *mpc8xxx_spi_strmode(unsigned int flags)
{
	if (flags & SPI_QE_CPU_MODE) {
		return "QE CPU";
	} else if (flags & SPI_CPM_MODE) {
		if (flags & SPI_QE)
			return "QE";
		else if (flags & SPI_CPM2)
			return "CPM2";
		else
			return "CPM1";
	}
	return "CPU";
}
EXPORT_SYMBOL_GPL(mpc8xxx_spi_strmode);

void mpc8xxx_spi_probe(struct device *dev, struct resource *mem,
			unsigned int irq)
{
	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
	struct spi_master *master;
	struct mpc8xxx_spi *mpc8xxx_spi;

	master = dev_get_drvdata(dev);

	/* the spi->mode bits understood by this driver: */
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH
			| SPI_LSB_FIRST | SPI_LOOP;

	master->dev.of_node = dev->of_node;

	mpc8xxx_spi = spi_master_get_devdata(master);
	mpc8xxx_spi->dev = dev;
	mpc8xxx_spi->get_rx = mpc8xxx_spi_rx_buf_u8;
	mpc8xxx_spi->get_tx = mpc8xxx_spi_tx_buf_u8;
	mpc8xxx_spi->flags = pdata->flags;
	mpc8xxx_spi->spibrg = pdata->sysclk;
	mpc8xxx_spi->irq = irq;

	mpc8xxx_spi->rx_shift = 0;
	mpc8xxx_spi->tx_shift = 0;

	master->bus_num = pdata->bus_num;
	master->num_chipselect = pdata->max_chipselect;

	init_completion(&mpc8xxx_spi->done);
}
EXPORT_SYMBOL_GPL(mpc8xxx_spi_probe);

int of_mpc8xxx_spi_probe(struct platform_device *ofdev)
{
	struct device *dev = &ofdev->dev;
	struct device_node *np = ofdev->dev.of_node;
	struct mpc8xxx_spi_probe_info *pinfo;
	struct fsl_spi_platform_data *pdata;
	const void *prop;
	int ret = -ENOMEM;

	pinfo = devm_kzalloc(&ofdev->dev, sizeof(*pinfo), GFP_KERNEL);
	if (!pinfo)
		return ret;

	pdata = &pinfo->pdata;
	dev->platform_data = pdata;

	/* Allocate bus num dynamically. */
	pdata->bus_num = -1;

#ifdef CONFIG_FSL_SOC
	/* SPI controller is either clocked from QE or SoC clock. */
	pdata->sysclk = get_brgfreq();
	if (pdata->sysclk == -1) {
		pdata->sysclk = fsl_get_sys_freq();
		if (pdata->sysclk == -1)
			return -ENODEV;
	}
#else
	ret = of_property_read_u32(np, "clock-frequency", &pdata->sysclk);
	if (ret)
		return ret;
#endif

	prop = of_get_property(np, "mode", NULL);
	if (prop && !strcmp(prop, "cpu-qe"))
		pdata->flags = SPI_QE_CPU_MODE;
	else if (prop && !strcmp(prop, "qe"))
		pdata->flags = SPI_CPM_MODE | SPI_QE;
	else if (of_device_is_compatible(np, "fsl,cpm2-spi"))
		pdata->flags = SPI_CPM_MODE | SPI_CPM2;
	else if (of_device_is_compatible(np, "fsl,cpm1-spi"))
		pdata->flags = SPI_CPM_MODE | SPI_CPM1;

	return 0;
}
EXPORT_SYMBOL_GPL(of_mpc8xxx_spi_probe);

MODULE_LICENSE("GPL");