linux/drivers/spi/spi-lp8841-rtc.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * SPI host driver for ICP DAS LP-8841 RTC
 *
 * Copyright (C) 2016 Sergei Ianovich
 *
 * based on
 *
 * Dallas DS1302 RTC Support
 * Copyright (C) 2002 David McCullough
 * Copyright (C) 2003 - 2007 Paul Mundt
 */
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/spi/spi.h>

#define DRIVER_NAME …

#define SPI_LP8841_RTC_CE …
#define SPI_LP8841_RTC_CLK …
#define SPI_LP8841_RTC_nWE …
#define SPI_LP8841_RTC_MOSI …
#define SPI_LP8841_RTC_MISO …

/*
 * REVISIT If there is support for SPI_3WIRE and SPI_LSB_FIRST in SPI
 * GPIO driver, this SPI driver can be replaced by a simple GPIO driver
 * providing 3 GPIO pins.
 */

struct spi_lp8841_rtc { … };

static inline void
setsck(struct spi_lp8841_rtc *data, int is_on)
{ … }

static inline void
setmosi(struct spi_lp8841_rtc *data, int is_on)
{ … }

static inline int
getmiso(struct spi_lp8841_rtc *data)
{ … }

static inline u32
bitbang_txrx_be_cpha0_lsb(struct spi_lp8841_rtc *data,
		unsigned usecs, unsigned cpol, unsigned flags,
		u32 word, u8 bits)
{ … }

static int
spi_lp8841_rtc_transfer_one(struct spi_controller *host,
			    struct spi_device *spi,
			    struct spi_transfer *t)
{ … }

static void
spi_lp8841_rtc_set_cs(struct spi_device *spi, bool enable)
{ … }

static int
spi_lp8841_rtc_setup(struct spi_device *spi)
{ … }

#ifdef CONFIG_OF
static const struct of_device_id spi_lp8841_rtc_dt_ids[] = …;

MODULE_DEVICE_TABLE(of, spi_lp8841_rtc_dt_ids);
#endif

static int
spi_lp8841_rtc_probe(struct platform_device *pdev)
{ … }

MODULE_ALIAS(…) …;

static struct platform_driver spi_lp8841_rtc_driver = …;
module_platform_driver(…) …;

MODULE_DESCRIPTION(…) …;
MODULE_AUTHOR(…) …;
MODULE_LICENSE(…) …;