// SPDX-License-Identifier: GPL-2.0-only /* * Microchip PIC32 SPI controller driver. * * Purna Chandra Mandal <[email protected]> * Copyright (c) 2016, Microchip Technology Inc. */ #include <linux/clk.h> #include <linux/clkdev.h> #include <linux/delay.h> #include <linux/dmaengine.h> #include <linux/dma-mapping.h> #include <linux/gpio/consumer.h> #include <linux/highmem.h> #include <linux/module.h> #include <linux/io.h> #include <linux/interrupt.h> #include <linux/of.h> #include <linux/of_irq.h> #include <linux/of_address.h> #include <linux/platform_device.h> #include <linux/spi/spi.h> /* SPI controller registers */ struct pic32_spi_regs { … }; /* Bit fields of SPI Control Register */ #define CTRL_RX_INT_SHIFT … #define RX_FIFO_EMPTY … #define RX_FIFO_NOT_EMPTY … #define RX_FIFO_HALF_FULL … #define RX_FIFO_FULL … #define CTRL_TX_INT_SHIFT … #define TX_FIFO_ALL_EMPTY … #define TX_FIFO_EMPTY … #define TX_FIFO_HALF_EMPTY … #define TX_FIFO_NOT_FULL … #define CTRL_MSTEN … #define CTRL_CKP … #define CTRL_CKE … #define CTRL_SMP … #define CTRL_BPW_MASK … #define CTRL_BPW_SHIFT … #define PIC32_BPW_8 … #define PIC32_BPW_16 … #define PIC32_BPW_32 … #define CTRL_SIDL … #define CTRL_ON … #define CTRL_ENHBUF … #define CTRL_MCLKSEL … #define CTRL_MSSEN … #define CTRL_FRMEN … /* Bit fields of SPI Status Register */ #define STAT_RF_EMPTY … #define STAT_RX_OV … #define STAT_TX_UR … #define STAT_FRM_ERR … #define STAT_TF_LVL_MASK … #define STAT_TF_LVL_SHIFT … #define STAT_RF_LVL_MASK … #define STAT_RF_LVL_SHIFT … /* Bit fields of SPI Baud Register */ #define BAUD_MASK … /* Bit fields of SPI Control2 Register */ #define CTRL2_TX_UR_EN … #define CTRL2_RX_OV_EN … #define CTRL2_FRM_ERR_EN … /* Minimum DMA transfer size */ #define PIC32_DMA_LEN_MIN … struct pic32_spi { … }; static inline void pic32_spi_enable(struct pic32_spi *pic32s) { … } static inline void pic32_spi_disable(struct pic32_spi *pic32s) { … } static void pic32_spi_set_clk_rate(struct pic32_spi *pic32s, u32 spi_ck) { … } static inline u32 pic32_rx_fifo_level(struct pic32_spi *pic32s) { … } static inline u32 pic32_tx_fifo_level(struct pic32_spi *pic32s) { … } /* Return the max entries we can fill into tx fifo */ static u32 pic32_tx_max(struct pic32_spi *pic32s, int n_bytes) { … } /* Return the max entries we should read out of rx fifo */ static u32 pic32_rx_max(struct pic32_spi *pic32s, int n_bytes) { … } #define BUILD_SPI_FIFO_RW(__name, __type, __bwl) … BUILD_SPI_FIFO_RW(byte, u8, b); BUILD_SPI_FIFO_RW(word, u16, w); BUILD_SPI_FIFO_RW(dword, u32, l); static void pic32_err_stop(struct pic32_spi *pic32s, const char *msg) { … } static irqreturn_t pic32_spi_fault_irq(int irq, void *dev_id) { … } static irqreturn_t pic32_spi_rx_irq(int irq, void *dev_id) { … } static irqreturn_t pic32_spi_tx_irq(int irq, void *dev_id) { … } static void pic32_spi_dma_rx_notify(void *data) { … } static int pic32_spi_dma_transfer(struct pic32_spi *pic32s, struct spi_transfer *xfer) { … } static int pic32_spi_dma_config(struct pic32_spi *pic32s, u32 dma_width) { … } static int pic32_spi_set_word_size(struct pic32_spi *pic32s, u8 bits_per_word) { … } static int pic32_spi_prepare_hardware(struct spi_controller *host) { … } static int pic32_spi_prepare_message(struct spi_controller *host, struct spi_message *msg) { … } static bool pic32_spi_can_dma(struct spi_controller *host, struct spi_device *spi, struct spi_transfer *xfer) { … } static int pic32_spi_one_transfer(struct spi_controller *host, struct spi_device *spi, struct spi_transfer *transfer) { … } static int pic32_spi_unprepare_message(struct spi_controller *host, struct spi_message *msg) { … } static int pic32_spi_unprepare_hardware(struct spi_controller *host) { … } /* This may be called multiple times by same spi dev */ static int pic32_spi_setup(struct spi_device *spi) { … } static void pic32_spi_cleanup(struct spi_device *spi) { … } static int pic32_spi_dma_prep(struct pic32_spi *pic32s, struct device *dev) { … } static void pic32_spi_dma_unprep(struct pic32_spi *pic32s) { … } static void pic32_spi_hw_init(struct pic32_spi *pic32s) { … } static int pic32_spi_hw_probe(struct platform_device *pdev, struct pic32_spi *pic32s) { … } static int pic32_spi_probe(struct platform_device *pdev) { … } static void pic32_spi_remove(struct platform_device *pdev) { … } static const struct of_device_id pic32_spi_of_match[] = …; MODULE_DEVICE_TABLE(of, pic32_spi_of_match); static struct platform_driver pic32_spi_driver = …; module_platform_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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