// SPDX-License-Identifier: GPL-2.0-or-later /* * Driver for Broadcom BCM2835 auxiliary SPI Controllers * * the driver does not rely on the native chipselects at all * but only uses the gpio type chipselects * * Based on: spi-bcm2835.c * * Copyright (C) 2015 Martin Sperl */ #include <linux/clk.h> #include <linux/completion.h> #include <linux/debugfs.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/regmap.h> #include <linux/spi/spi.h> #include <linux/spinlock.h> /* define polling limits */ static unsigned int polling_limit_us = …; module_param(polling_limit_us, uint, 0664); MODULE_PARM_DESC(…) …; /* * spi register defines * * note there is garbage in the "official" documentation, * so some data is taken from the file: * brcm_usrlib/dag/vmcsx/vcinclude/bcm2708_chip/aux_io.h * inside of: * http://www.broadcom.com/docs/support/videocore/Brcm_Android_ICS_Graphics_Stack.tar.gz */ /* SPI register offsets */ #define BCM2835_AUX_SPI_CNTL0 … #define BCM2835_AUX_SPI_CNTL1 … #define BCM2835_AUX_SPI_STAT … #define BCM2835_AUX_SPI_PEEK … #define BCM2835_AUX_SPI_IO … #define BCM2835_AUX_SPI_TXHOLD … /* Bitfields in CNTL0 */ #define BCM2835_AUX_SPI_CNTL0_SPEED … #define BCM2835_AUX_SPI_CNTL0_SPEED_MAX … #define BCM2835_AUX_SPI_CNTL0_SPEED_SHIFT … #define BCM2835_AUX_SPI_CNTL0_CS … #define BCM2835_AUX_SPI_CNTL0_POSTINPUT … #define BCM2835_AUX_SPI_CNTL0_VAR_CS … #define BCM2835_AUX_SPI_CNTL0_VAR_WIDTH … #define BCM2835_AUX_SPI_CNTL0_DOUTHOLD … #define BCM2835_AUX_SPI_CNTL0_ENABLE … #define BCM2835_AUX_SPI_CNTL0_IN_RISING … #define BCM2835_AUX_SPI_CNTL0_CLEARFIFO … #define BCM2835_AUX_SPI_CNTL0_OUT_RISING … #define BCM2835_AUX_SPI_CNTL0_CPOL … #define BCM2835_AUX_SPI_CNTL0_MSBF_OUT … #define BCM2835_AUX_SPI_CNTL0_SHIFTLEN … /* Bitfields in CNTL1 */ #define BCM2835_AUX_SPI_CNTL1_CSHIGH … #define BCM2835_AUX_SPI_CNTL1_TXEMPTY … #define BCM2835_AUX_SPI_CNTL1_IDLE … #define BCM2835_AUX_SPI_CNTL1_MSBF_IN … #define BCM2835_AUX_SPI_CNTL1_KEEP_IN … /* Bitfields in STAT */ #define BCM2835_AUX_SPI_STAT_TX_LVL … #define BCM2835_AUX_SPI_STAT_RX_LVL … #define BCM2835_AUX_SPI_STAT_TX_FULL … #define BCM2835_AUX_SPI_STAT_TX_EMPTY … #define BCM2835_AUX_SPI_STAT_RX_FULL … #define BCM2835_AUX_SPI_STAT_RX_EMPTY … #define BCM2835_AUX_SPI_STAT_BUSY … #define BCM2835_AUX_SPI_STAT_BITCOUNT … struct bcm2835aux_spi { … }; #if defined(CONFIG_DEBUG_FS) static void bcm2835aux_debugfs_create(struct bcm2835aux_spi *bs, const char *dname) { … } static void bcm2835aux_debugfs_remove(struct bcm2835aux_spi *bs) { … } #else static void bcm2835aux_debugfs_create(struct bcm2835aux_spi *bs, const char *dname) { } static void bcm2835aux_debugfs_remove(struct bcm2835aux_spi *bs) { } #endif /* CONFIG_DEBUG_FS */ static inline u32 bcm2835aux_rd(struct bcm2835aux_spi *bs, unsigned int reg) { … } static inline void bcm2835aux_wr(struct bcm2835aux_spi *bs, unsigned int reg, u32 val) { … } static inline void bcm2835aux_rd_fifo(struct bcm2835aux_spi *bs) { … } static inline void bcm2835aux_wr_fifo(struct bcm2835aux_spi *bs) { … } static void bcm2835aux_spi_reset_hw(struct bcm2835aux_spi *bs) { … } static void bcm2835aux_spi_transfer_helper(struct bcm2835aux_spi *bs) { … } static irqreturn_t bcm2835aux_spi_interrupt(int irq, void *dev_id) { … } static int __bcm2835aux_spi_transfer_one_irq(struct spi_controller *host, struct spi_device *spi, struct spi_transfer *tfr) { … } static int bcm2835aux_spi_transfer_one_irq(struct spi_controller *host, struct spi_device *spi, struct spi_transfer *tfr) { … } static int bcm2835aux_spi_transfer_one_poll(struct spi_controller *host, struct spi_device *spi, struct spi_transfer *tfr) { … } static int bcm2835aux_spi_transfer_one(struct spi_controller *host, struct spi_device *spi, struct spi_transfer *tfr) { … } static int bcm2835aux_spi_prepare_message(struct spi_controller *host, struct spi_message *msg) { … } static int bcm2835aux_spi_unprepare_message(struct spi_controller *host, struct spi_message *msg) { … } static void bcm2835aux_spi_handle_err(struct spi_controller *host, struct spi_message *msg) { … } static int bcm2835aux_spi_setup(struct spi_device *spi) { … } static int bcm2835aux_spi_probe(struct platform_device *pdev) { … } static void bcm2835aux_spi_remove(struct platform_device *pdev) { … } static const struct of_device_id bcm2835aux_spi_match[] = …; MODULE_DEVICE_TABLE(of, bcm2835aux_spi_match); static struct platform_driver bcm2835aux_spi_driver = …; module_platform_driver(…) …; MODULE_DESCRIPTION(…) …; MODULE_AUTHOR(…) …; MODULE_LICENSE(…) …;
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