// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2009 Texas Instruments. * Copyright (C) 2010 EF Johnson Technologies */ #include <linux/interrupt.h> #include <linux/io.h> #include <linux/gpio/consumer.h> #include <linux/module.h> #include <linux/delay.h> #include <linux/platform_device.h> #include <linux/err.h> #include <linux/clk.h> #include <linux/dmaengine.h> #include <linux/dma-mapping.h> #include <linux/of.h> #include <linux/spi/spi.h> #include <linux/spi/spi_bitbang.h> #include <linux/slab.h> #include <linux/platform_data/spi-davinci.h> #define CS_DEFAULT … #define SPIFMT_PHASE_MASK … #define SPIFMT_POLARITY_MASK … #define SPIFMT_DISTIMER_MASK … #define SPIFMT_SHIFTDIR_MASK … #define SPIFMT_WAITENA_MASK … #define SPIFMT_PARITYENA_MASK … #define SPIFMT_ODD_PARITY_MASK … #define SPIFMT_WDELAY_MASK … #define SPIFMT_WDELAY_SHIFT … #define SPIFMT_PRESCALE_SHIFT … /* SPIPC0 */ #define SPIPC0_DIFUN_MASK … #define SPIPC0_DOFUN_MASK … #define SPIPC0_CLKFUN_MASK … #define SPIPC0_SPIENA_MASK … #define SPIINT_MASKALL … #define SPIINT_MASKINT … #define SPI_INTLVL_1 … #define SPI_INTLVL_0 … /* SPIDAT1 (upper 16 bit defines) */ #define SPIDAT1_CSHOLD_MASK … #define SPIDAT1_WDEL … /* SPIGCR1 */ #define SPIGCR1_CLKMOD_MASK … #define SPIGCR1_MASTER_MASK … #define SPIGCR1_POWERDOWN_MASK … #define SPIGCR1_LOOPBACK_MASK … #define SPIGCR1_SPIENA_MASK … /* SPIBUF */ #define SPIBUF_TXFULL_MASK … #define SPIBUF_RXEMPTY_MASK … /* SPIDELAY */ #define SPIDELAY_C2TDELAY_SHIFT … #define SPIDELAY_C2TDELAY_MASK … #define SPIDELAY_T2CDELAY_SHIFT … #define SPIDELAY_T2CDELAY_MASK … #define SPIDELAY_T2EDELAY_SHIFT … #define SPIDELAY_T2EDELAY_MASK … #define SPIDELAY_C2EDELAY_SHIFT … #define SPIDELAY_C2EDELAY_MASK … /* Error Masks */ #define SPIFLG_DLEN_ERR_MASK … #define SPIFLG_TIMEOUT_MASK … #define SPIFLG_PARERR_MASK … #define SPIFLG_DESYNC_MASK … #define SPIFLG_BITERR_MASK … #define SPIFLG_OVRRUN_MASK … #define SPIFLG_BUF_INIT_ACTIVE_MASK … #define SPIFLG_ERROR_MASK … #define SPIINT_DMA_REQ_EN … /* SPI Controller registers */ #define SPIGCR0 … #define SPIGCR1 … #define SPIINT … #define SPILVL … #define SPIFLG … #define SPIPC0 … #define SPIDAT1 … #define SPIBUF … #define SPIDELAY … #define SPIDEF … #define SPIFMT0 … #define DMA_MIN_BYTES … /* SPI Controller driver's private data. */ struct davinci_spi { … }; static struct davinci_spi_config davinci_spi_default_cfg; static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *dspi) { … } static void davinci_spi_rx_buf_u16(u32 data, struct davinci_spi *dspi) { … } static u32 davinci_spi_tx_buf_u8(struct davinci_spi *dspi) { … } static u32 davinci_spi_tx_buf_u16(struct davinci_spi *dspi) { … } static inline void set_io_bits(void __iomem *addr, u32 bits) { … } static inline void clear_io_bits(void __iomem *addr, u32 bits) { … } /* * Interface to control the chip select signal */ static void davinci_spi_chipselect(struct spi_device *spi, int value) { … } /** * davinci_spi_get_prescale - Calculates the correct prescale value * @dspi: the controller data * @max_speed_hz: the maximum rate the SPI clock can run at * * This function calculates the prescale value that generates a clock rate * less than or equal to the specified maximum. * * Returns: calculated prescale value for easy programming into SPI registers * or negative error number if valid prescalar cannot be updated. */ static inline int davinci_spi_get_prescale(struct davinci_spi *dspi, u32 max_speed_hz) { … } /** * davinci_spi_setup_transfer - This functions will determine transfer method * @spi: spi device on which data transfer to be done * @t: spi transfer in which transfer info is filled * * This function determines data transfer method (8/16/32 bit transfer). * It will also set the SPI Clock Control register according to * SPI slave device freq. */ static int davinci_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) { … } static int davinci_spi_of_setup(struct spi_device *spi) { … } /** * davinci_spi_setup - This functions will set default transfer method * @spi: spi device on which data transfer to be done * * This functions sets the default transfer method. */ static int davinci_spi_setup(struct spi_device *spi) { … } static void davinci_spi_cleanup(struct spi_device *spi) { … } static bool davinci_spi_can_dma(struct spi_controller *host, struct spi_device *spi, struct spi_transfer *xfer) { … } static int davinci_spi_check_error(struct davinci_spi *dspi, int int_status) { … } /** * davinci_spi_process_events - check for and handle any SPI controller events * @dspi: the controller data * * This function will check the SPIFLG register and handle any events that are * detected there */ static int davinci_spi_process_events(struct davinci_spi *dspi) { … } static void davinci_spi_dma_rx_callback(void *data) { … } static void davinci_spi_dma_tx_callback(void *data) { … } /** * davinci_spi_bufs - functions which will handle transfer data * @spi: spi device on which data transfer to be done * @t: spi transfer in which transfer info is filled * * This function will put data to be transferred into data register * of SPI controller and then wait until the completion will be marked * by the IRQ Handler. */ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t) { … } /** * dummy_thread_fn - dummy thread function * @irq: IRQ number for this SPI Master * @data: structure for SPI Master controller davinci_spi * * This is to satisfy the request_threaded_irq() API so that the irq * handler is called in interrupt context. */ static irqreturn_t dummy_thread_fn(s32 irq, void *data) { … } /** * davinci_spi_irq - Interrupt handler for SPI Master Controller * @irq: IRQ number for this SPI Master * @data: structure for SPI Master controller davinci_spi * * ISR will determine that interrupt arrives either for READ or WRITE command. * According to command it will do the appropriate action. It will check * transfer length and if it is not zero then dispatch transfer command again. * If transfer length is zero then it will indicate the COMPLETION so that * davinci_spi_bufs function can go ahead. */ static irqreturn_t davinci_spi_irq(s32 irq, void *data) { … } static int davinci_spi_request_dma(struct davinci_spi *dspi) { … } #if defined(CONFIG_OF) /* OF SPI data structure */ struct davinci_spi_of_data { … }; static const struct davinci_spi_of_data dm6441_spi_data = …; static const struct davinci_spi_of_data da830_spi_data = …; static const struct davinci_spi_of_data keystone_spi_data = …; static const struct of_device_id davinci_spi_of_match[] = …; MODULE_DEVICE_TABLE(of, davinci_spi_of_match); /** * spi_davinci_get_pdata - Get platform data from DTS binding * @pdev: ptr to platform data * @dspi: ptr to driver data * * Parses and populates pdata in dspi from device tree bindings. * * NOTE: Not all platform data params are supported currently. */ static int spi_davinci_get_pdata(struct platform_device *pdev, struct davinci_spi *dspi) { … } #else static int spi_davinci_get_pdata(struct platform_device *pdev, struct davinci_spi *dspi) { return -ENODEV; } #endif /** * davinci_spi_probe - probe function for SPI Master Controller * @pdev: platform_device structure which contains plateform specific data * * According to Linux Device Model this function will be invoked by Linux * with platform_device struct which contains the device specific info. * This function will map the SPI controller's memory, register IRQ, * Reset SPI controller and setting its registers to default value. * It will invoke spi_bitbang_start to create work queue so that client driver * can register transfer method to work queue. */ static int davinci_spi_probe(struct platform_device *pdev) { … } /** * davinci_spi_remove - remove function for SPI Master Controller * @pdev: platform_device structure which contains plateform specific data * * This function will do the reverse action of davinci_spi_probe function * It will free the IRQ and SPI controller's memory region. * It will also call spi_bitbang_stop to destroy the work queue which was * created by spi_bitbang_start. */ static void davinci_spi_remove(struct platform_device *pdev) { … } static struct platform_driver davinci_spi_driver = …; module_platform_driver(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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