diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-at91.h')
| -rw-r--r-- | drivers/i2c/busses/i2c-at91.h | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-at91.h b/drivers/i2c/busses/i2c-at91.h new file mode 100644 index 000000000000..499b506f6128 --- /dev/null +++ b/drivers/i2c/busses/i2c-at91.h @@ -0,0 +1,174 @@ +/* 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_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_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(len) ((len) & 0xff) +#define AT91_TWI_ACR_DIR BIT(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; + 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; +#ifdef CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL + unsigned smr; + struct i2c_client *slave; +#endif +}; + +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 |