drivers/i2c/busses/i2c-at91.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */
 /*
  *  i2c Support for Atmel's AT91 Two-Wire Interface (TWI)
  *
  *  Copyright (C) 2011 Weinmann Medical GmbH
  *  Author: Nikolaus Voss <n.voss@weinmann.de>
  *
  *  Evolved from original work by:
  *  Copyright (C) 2004 Rick Bronson
  *  Converted to 2.6 by Andrew Victor <andrew@sanpeople.com>
  *
  *  Borrowed heavily from original work by:
  *  Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
  */

 #include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
 #include <linux/i2c.h>
 #include <linux/platform_data/dma-atmel.h>
 #include <linux/platform_device.h>

 #define AT91_I2C_TIMEOUT	msecs_to_jiffies(100)	/* transfer timeout */
 #define AT91_I2C_DMA_THRESHOLD	8			/* enable DMA if transfer size is bigger than this threshold */
 #define AUTOSUSPEND_TIMEOUT		2000
 #define AT91_I2C_MAX_ALT_CMD_DATA_SIZE	256

 /* AT91 TWI register definitions */
 #define	AT91_TWI_CR		0x0000	/* Control Register */
 #define	AT91_TWI_START		BIT(0)	/* Send a Start Condition */
 #define	AT91_TWI_STOP		BIT(1)	/* Send a Stop Condition */
 #define	AT91_TWI_MSEN		BIT(2)	/* Master Transfer Enable */
 #define	AT91_TWI_MSDIS		BIT(3)	/* Master Transfer Disable */
 #define	AT91_TWI_SVEN		BIT(4)	/* Slave Transfer Enable */
 #define	AT91_TWI_SVDIS		BIT(5)	/* Slave Transfer Disable */
 #define	AT91_TWI_QUICK		BIT(6)	/* SMBus quick command */
 #define	AT91_TWI_SWRST		BIT(7)	/* Software Reset */
 #define	AT91_TWI_CLEAR		BIT(15) /* Bus clear command */
 #define	AT91_TWI_ACMEN		BIT(16) /* Alternative Command Mode Enable */
 #define	AT91_TWI_ACMDIS		BIT(17) /* Alternative Command Mode Disable */
 #define	AT91_TWI_THRCLR		BIT(24) /* Transmit Holding Register Clear */
 #define	AT91_TWI_RHRCLR		BIT(25) /* Receive Holding Register Clear */
 #define	AT91_TWI_LOCKCLR	BIT(26) /* Lock Clear */
 #define	AT91_TWI_FIFOEN		BIT(28) /* FIFO Enable */
 #define	AT91_TWI_FIFODIS	BIT(29) /* FIFO Disable */

 #define	AT91_TWI_MMR		0x0004	/* Master Mode Register */
 #define	AT91_TWI_IADRSZ_1	0x0100	/* Internal Device Address Size */
 #define	AT91_TWI_MREAD		BIT(12)	/* Master Read Direction */

 #define	AT91_TWI_SMR		0x0008	/* Slave Mode Register */
 #define	AT91_TWI_SMR_SADR_MAX	0x007f
 #define	AT91_TWI_SMR_SADR(x)	(((x) & AT91_TWI_SMR_SADR_MAX) << 16)

 #define	AT91_TWI_IADR		0x000c	/* Internal Address Register */

 #define	AT91_TWI_CWGR		0x0010	/* Clock Waveform Generator Reg */
 #define	AT91_TWI_CWGR_HOLD_MAX	0x1f
 #define	AT91_TWI_CWGR_HOLD(x)	(((x) & AT91_TWI_CWGR_HOLD_MAX) << 24)

 #define	AT91_TWI_SR		0x0020	/* Status Register */
 #define	AT91_TWI_TXCOMP		BIT(0)	/* Transmission Complete */
 #define	AT91_TWI_RXRDY		BIT(1)	/* Receive Holding Register Ready */
 #define	AT91_TWI_TXRDY		BIT(2)	/* Transmit Holding Register Ready */
 #define	AT91_TWI_SVREAD		BIT(3)	/* Slave Read */
 #define	AT91_TWI_SVACC		BIT(4)	/* Slave Access */
 #define	AT91_TWI_OVRE		BIT(6)	/* Overrun Error */
 #define	AT91_TWI_UNRE		BIT(7)	/* Underrun Error */
 #define	AT91_TWI_NACK		BIT(8)	/* Not Acknowledged */
 #define	AT91_TWI_EOSACC		BIT(11)	/* End Of Slave Access */
 #define	AT91_TWI_LOCK		BIT(23) /* TWI Lock due to Frame Errors */
 #define	AT91_TWI_SCL		BIT(24) /* TWI SCL status */
 #define	AT91_TWI_SDA		BIT(25) /* TWI SDA status */

 #define	AT91_TWI_INT_MASK \
 	(AT91_TWI_TXCOMP | AT91_TWI_RXRDY | AT91_TWI_TXRDY | AT91_TWI_NACK \
 	| AT91_TWI_SVACC | AT91_TWI_EOSACC)

 #define	AT91_TWI_IER		0x0024	/* Interrupt Enable Register */
 #define	AT91_TWI_IDR		0x0028	/* Interrupt Disable Register */
 #define	AT91_TWI_IMR		0x002c	/* Interrupt Mask Register */
 #define	AT91_TWI_RHR		0x0030	/* Receive Holding Register */
 #define	AT91_TWI_THR		0x0034	/* Transmit Holding Register */

 #define	AT91_TWI_ACR		0x0040	/* Alternative Command Register */
 #define	AT91_TWI_ACR_DATAL_MASK	GENMASK(15, 0)
 #define	AT91_TWI_ACR_DATAL(len)	((len) & AT91_TWI_ACR_DATAL_MASK)
 #define	AT91_TWI_ACR_DIR	BIT(8)

 #define AT91_TWI_FILTR		0x0044
 #define AT91_TWI_FILTR_FILT	BIT(0)
 #define AT91_TWI_FILTR_PADFEN	BIT(1)
 #define AT91_TWI_FILTR_THRES(v)		((v) << 8)
 #define AT91_TWI_FILTR_THRES_MAX	7
 #define AT91_TWI_FILTR_THRES_MASK	GENMASK(10, 8)

 #define	AT91_TWI_FMR		0x0050	/* FIFO Mode Register */
 #define	AT91_TWI_FMR_TXRDYM(mode)	(((mode) & 0x3) << 0)
 #define	AT91_TWI_FMR_TXRDYM_MASK	(0x3 << 0)
 #define	AT91_TWI_FMR_RXRDYM(mode)	(((mode) & 0x3) << 4)
 #define	AT91_TWI_FMR_RXRDYM_MASK	(0x3 << 4)
 #define	AT91_TWI_ONE_DATA	0x0
 #define	AT91_TWI_TWO_DATA	0x1
 #define	AT91_TWI_FOUR_DATA	0x2

 #define	AT91_TWI_FLR		0x0054	/* FIFO Level Register */

 #define	AT91_TWI_FSR		0x0060	/* FIFO Status Register */
 #define	AT91_TWI_FIER		0x0064	/* FIFO Interrupt Enable Register */
 #define	AT91_TWI_FIDR		0x0068	/* FIFO Interrupt Disable Register */
 #define	AT91_TWI_FIMR		0x006c	/* FIFO Interrupt Mask Register */

 #define	AT91_TWI_VER		0x00fc	/* Version Register */

 struct at91_twi_pdata {
 	unsigned clk_max_div;
 	unsigned clk_offset;
 	bool has_unre_flag;
 	bool has_alt_cmd;
 	bool has_hold_field;
 	bool has_dig_filtr;
 	bool has_adv_dig_filtr;
 	bool has_ana_filtr;
 	bool has_clear_cmd;
 	struct at_dma_slave dma_slave;
 };

 struct at91_twi_dma {
 	struct dma_chan *chan_rx;
 	struct dma_chan *chan_tx;
 	struct scatterlist sg[2];
 	struct dma_async_tx_descriptor *data_desc;
 	enum dma_data_direction direction;
 	bool buf_mapped;
 	bool xfer_in_progress;
 };

 struct at91_twi_dev {
 	struct device *dev;
 	void __iomem *base;
 	struct completion cmd_complete;
 	struct clk *clk;
 	u8 *buf;
 	size_t buf_len;
 	struct i2c_msg *msg;
 	int irq;
 	unsigned imr;
 	unsigned transfer_status;
 	struct i2c_adapter adapter;
 	unsigned twi_cwgr_reg;
 	struct at91_twi_pdata *pdata;
 	bool use_dma;
 	bool use_alt_cmd;
 	bool recv_len_abort;
 	u32 fifo_size;
 	struct at91_twi_dma dma;
 	bool slave_detected;
 	struct i2c_bus_recovery_info rinfo;
 #ifdef CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL
 	unsigned smr;
 	struct i2c_client *slave;
 #endif
 	bool enable_dig_filt;
 	bool enable_ana_filt;
 	u32 filter_width;
 };

 unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg);
 void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val);
 void at91_disable_twi_interrupts(struct at91_twi_dev *dev);
 void at91_twi_irq_save(struct at91_twi_dev *dev);
 void at91_twi_irq_restore(struct at91_twi_dev *dev);
 void at91_init_twi_bus(struct at91_twi_dev *dev);

 void at91_init_twi_bus_master(struct at91_twi_dev *dev);
 int at91_twi_probe_master(struct platform_device *pdev, u32 phy_addr,
 			  struct at91_twi_dev *dev);

 #ifdef CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL
 void at91_init_twi_bus_slave(struct at91_twi_dev *dev);
 int at91_twi_probe_slave(struct platform_device *pdev, u32 phy_addr,
 			 struct at91_twi_dev *dev);

 #else
 static inline void at91_init_twi_bus_slave(struct at91_twi_dev *dev) {}
 static inline int at91_twi_probe_slave(struct platform_device *pdev,
 				       u32 phy_addr, struct at91_twi_dev *dev)
 {
 	return -EINVAL;
 }

 #endif
	/* SPDX-License-Identifier: GPL-2.0 */
	/*
	* i2c Support for Atmel's AT91 Two-Wire Interface (TWI)
	*
	* Copyright (C) 2011 Weinmann Medical GmbH
	* Author: Nikolaus Voss <n.voss@weinmann.de>
	*
	* Evolved from original work by:
	* Copyright (C) 2004 Rick Bronson
	* Converted to 2.6 by Andrew Victor <andrew@sanpeople.com>
	*
	* Borrowed heavily from original work by:
	* Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
	*/

	#include <linux/clk.h>
	#include <linux/completion.h>
	#include <linux/dma-mapping.h>
	#include <linux/dmaengine.h>
	#include <linux/i2c.h>
	#include <linux/platform_data/dma-atmel.h>
	#include <linux/platform_device.h>

	#define AT91_I2C_TIMEOUT msecs_to_jiffies(100) /* transfer timeout */
	#define AT91_I2C_DMA_THRESHOLD 8 /* enable DMA if transfer size is bigger than this threshold */
	#define AUTOSUSPEND_TIMEOUT 2000
	#define AT91_I2C_MAX_ALT_CMD_DATA_SIZE 256

	/* AT91 TWI register definitions */
	#define AT91_TWI_CR 0x0000 /* Control Register */
	#define AT91_TWI_START BIT(0) /* Send a Start Condition */
	#define AT91_TWI_STOP BIT(1) /* Send a Stop Condition */
	#define AT91_TWI_MSEN BIT(2) /* Master Transfer Enable */
	#define AT91_TWI_MSDIS BIT(3) /* Master Transfer Disable */
	#define AT91_TWI_SVEN BIT(4) /* Slave Transfer Enable */
	#define AT91_TWI_SVDIS BIT(5) /* Slave Transfer Disable */
	#define AT91_TWI_QUICK BIT(6) /* SMBus quick command */
	#define AT91_TWI_SWRST BIT(7) /* Software Reset */
	#define AT91_TWI_CLEAR BIT(15) /* Bus clear command */
	#define AT91_TWI_ACMEN BIT(16) /* Alternative Command Mode Enable */
	#define AT91_TWI_ACMDIS BIT(17) /* Alternative Command Mode Disable */
	#define AT91_TWI_THRCLR BIT(24) /* Transmit Holding Register Clear */
	#define AT91_TWI_RHRCLR BIT(25) /* Receive Holding Register Clear */
	#define AT91_TWI_LOCKCLR BIT(26) /* Lock Clear */
	#define AT91_TWI_FIFOEN BIT(28) /* FIFO Enable */
	#define AT91_TWI_FIFODIS BIT(29) /* FIFO Disable */

	#define AT91_TWI_MMR 0x0004 /* Master Mode Register */
	#define AT91_TWI_IADRSZ_1 0x0100 /* Internal Device Address Size */
	#define AT91_TWI_MREAD BIT(12) /* Master Read Direction */

	#define AT91_TWI_SMR 0x0008 /* Slave Mode Register */
	#define AT91_TWI_SMR_SADR_MAX 0x007f
	#define AT91_TWI_SMR_SADR(x) (((x) & AT91_TWI_SMR_SADR_MAX) << 16)

	#define AT91_TWI_IADR 0x000c /* Internal Address Register */

	#define AT91_TWI_CWGR 0x0010 /* Clock Waveform Generator Reg */
	#define AT91_TWI_CWGR_HOLD_MAX 0x1f
	#define AT91_TWI_CWGR_HOLD(x) (((x) & AT91_TWI_CWGR_HOLD_MAX) << 24)

	#define AT91_TWI_SR 0x0020 /* Status Register */
	#define AT91_TWI_TXCOMP BIT(0) /* Transmission Complete */
	#define AT91_TWI_RXRDY BIT(1) /* Receive Holding Register Ready */
	#define AT91_TWI_TXRDY BIT(2) /* Transmit Holding Register Ready */
	#define AT91_TWI_SVREAD BIT(3) /* Slave Read */
	#define AT91_TWI_SVACC BIT(4) /* Slave Access */
	#define AT91_TWI_OVRE BIT(6) /* Overrun Error */
	#define AT91_TWI_UNRE BIT(7) /* Underrun Error */
	#define AT91_TWI_NACK BIT(8) /* Not Acknowledged */
	#define AT91_TWI_EOSACC BIT(11) /* End Of Slave Access */
	#define AT91_TWI_LOCK BIT(23) /* TWI Lock due to Frame Errors */
	#define AT91_TWI_SCL BIT(24) /* TWI SCL status */
	#define AT91_TWI_SDA BIT(25) /* TWI SDA status */

	#define AT91_TWI_INT_MASK \
	(AT91_TWI_TXCOMP \| AT91_TWI_RXRDY \| AT91_TWI_TXRDY \| AT91_TWI_NACK \
	\| AT91_TWI_SVACC \| AT91_TWI_EOSACC)

	#define AT91_TWI_IER 0x0024 /* Interrupt Enable Register */
	#define AT91_TWI_IDR 0x0028 /* Interrupt Disable Register */
	#define AT91_TWI_IMR 0x002c /* Interrupt Mask Register */
	#define AT91_TWI_RHR 0x0030 /* Receive Holding Register */
	#define AT91_TWI_THR 0x0034 /* Transmit Holding Register */

	#define AT91_TWI_ACR 0x0040 /* Alternative Command Register */
	#define AT91_TWI_ACR_DATAL_MASK GENMASK(15, 0)
	#define AT91_TWI_ACR_DATAL(len) ((len) & AT91_TWI_ACR_DATAL_MASK)
	#define AT91_TWI_ACR_DIR BIT(8)

	#define AT91_TWI_FILTR 0x0044
	#define AT91_TWI_FILTR_FILT BIT(0)
	#define AT91_TWI_FILTR_PADFEN BIT(1)
	#define AT91_TWI_FILTR_THRES(v) ((v) << 8)
	#define AT91_TWI_FILTR_THRES_MAX 7
	#define AT91_TWI_FILTR_THRES_MASK GENMASK(10, 8)

	#define AT91_TWI_FMR 0x0050 /* FIFO Mode Register */
	#define AT91_TWI_FMR_TXRDYM(mode) (((mode) & 0x3) << 0)
	#define AT91_TWI_FMR_TXRDYM_MASK (0x3 << 0)
	#define AT91_TWI_FMR_RXRDYM(mode) (((mode) & 0x3) << 4)
	#define AT91_TWI_FMR_RXRDYM_MASK (0x3 << 4)
	#define AT91_TWI_ONE_DATA 0x0
	#define AT91_TWI_TWO_DATA 0x1
	#define AT91_TWI_FOUR_DATA 0x2

	#define AT91_TWI_FLR 0x0054 /* FIFO Level Register */

	#define AT91_TWI_FSR 0x0060 /* FIFO Status Register */
	#define AT91_TWI_FIER 0x0064 /* FIFO Interrupt Enable Register */
	#define AT91_TWI_FIDR 0x0068 /* FIFO Interrupt Disable Register */
	#define AT91_TWI_FIMR 0x006c /* FIFO Interrupt Mask Register */

	#define AT91_TWI_VER 0x00fc /* Version Register */

	struct at91_twi_pdata {
	unsigned clk_max_div;
	unsigned clk_offset;
	bool has_unre_flag;
	bool has_alt_cmd;
	bool has_hold_field;
	bool has_dig_filtr;
	bool has_adv_dig_filtr;
	bool has_ana_filtr;
	bool has_clear_cmd;
	struct at_dma_slave dma_slave;
	};

	struct at91_twi_dma {
	struct dma_chan *chan_rx;
	struct dma_chan *chan_tx;
	struct scatterlist sg[2];
	struct dma_async_tx_descriptor *data_desc;
	enum dma_data_direction direction;
	bool buf_mapped;
	bool xfer_in_progress;
	};

	struct at91_twi_dev {
	struct device *dev;
	void __iomem *base;
	struct completion cmd_complete;
	struct clk *clk;
	u8 *buf;
	size_t buf_len;
	struct i2c_msg *msg;
	int irq;
	unsigned imr;
	unsigned transfer_status;
	struct i2c_adapter adapter;
	unsigned twi_cwgr_reg;
	struct at91_twi_pdata *pdata;
	bool use_dma;
	bool use_alt_cmd;
	bool recv_len_abort;
	u32 fifo_size;
	struct at91_twi_dma dma;
	bool slave_detected;
	struct i2c_bus_recovery_info rinfo;
	#ifdef CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL
	unsigned smr;
	struct i2c_client *slave;
	#endif
	bool enable_dig_filt;
	bool enable_ana_filt;
	u32 filter_width;
	};

	unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg);
	void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val);
	void at91_disable_twi_interrupts(struct at91_twi_dev *dev);
	void at91_twi_irq_save(struct at91_twi_dev *dev);
	void at91_twi_irq_restore(struct at91_twi_dev *dev);
	void at91_init_twi_bus(struct at91_twi_dev *dev);

	void at91_init_twi_bus_master(struct at91_twi_dev *dev);
	int at91_twi_probe_master(struct platform_device *pdev, u32 phy_addr,
	struct at91_twi_dev *dev);

	#ifdef CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL
	void at91_init_twi_bus_slave(struct at91_twi_dev *dev);
	int at91_twi_probe_slave(struct platform_device *pdev, u32 phy_addr,
	struct at91_twi_dev *dev);

	#else
	static inline void at91_init_twi_bus_slave(struct at91_twi_dev *dev) {}
	static inline int at91_twi_probe_slave(struct platform_device *pdev,
	u32 phy_addr, struct at91_twi_dev *dev)
	{
	return -EINVAL;
	}

	#endif