220 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			220 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #include <linux/atomic.h>
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| #include <linux/clk.h>
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| #include <linux/delay.h>
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| #include <linux/device.h>
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| #include <linux/i2c.h>
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| #include <linux/i2c-smbus.h>
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| #include <linux/io.h>
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| #include <linux/kernel.h>
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| 
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| /* Controller command patterns */
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| #define SW_TWSI_V		BIT_ULL(63)	/* Valid bit */
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| #define SW_TWSI_EIA		BIT_ULL(61)	/* Extended internal address */
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| #define SW_TWSI_R		BIT_ULL(56)	/* Result or read bit */
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| #define SW_TWSI_SOVR		BIT_ULL(55)	/* Size override */
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| #define SW_TWSI_SIZE_SHIFT	52
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| #define SW_TWSI_ADDR_SHIFT	40
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| #define SW_TWSI_IA_SHIFT	32		/* Internal address */
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| 
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| /* Controller opcode word (bits 60:57) */
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| #define SW_TWSI_OP_SHIFT	57
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| #define SW_TWSI_OP_7		(0ULL << SW_TWSI_OP_SHIFT)
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| #define SW_TWSI_OP_7_IA		(1ULL << SW_TWSI_OP_SHIFT)
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| #define SW_TWSI_OP_10		(2ULL << SW_TWSI_OP_SHIFT)
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| #define SW_TWSI_OP_10_IA	(3ULL << SW_TWSI_OP_SHIFT)
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| #define SW_TWSI_OP_TWSI_CLK	(4ULL << SW_TWSI_OP_SHIFT)
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| #define SW_TWSI_OP_EOP		(6ULL << SW_TWSI_OP_SHIFT) /* Extended opcode */
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| 
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| /* Controller extended opcode word (bits 34:32) */
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| #define SW_TWSI_EOP_SHIFT	32
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| #define SW_TWSI_EOP_TWSI_DATA	(SW_TWSI_OP_EOP | 1ULL << SW_TWSI_EOP_SHIFT)
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| #define SW_TWSI_EOP_TWSI_CTL	(SW_TWSI_OP_EOP | 2ULL << SW_TWSI_EOP_SHIFT)
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| #define SW_TWSI_EOP_TWSI_CLKCTL	(SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
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| #define SW_TWSI_EOP_TWSI_STAT	(SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
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| #define SW_TWSI_EOP_TWSI_RST	(SW_TWSI_OP_EOP | 7ULL << SW_TWSI_EOP_SHIFT)
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| 
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| /* Controller command and status bits */
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| #define TWSI_CTL_CE		0x80	/* High level controller enable */
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| #define TWSI_CTL_ENAB		0x40	/* Bus enable */
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| #define TWSI_CTL_STA		0x20	/* Master-mode start, HW clears when done */
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| #define TWSI_CTL_STP		0x10	/* Master-mode stop, HW clears when done */
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| #define TWSI_CTL_IFLG		0x08	/* HW event, SW writes 0 to ACK */
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| #define TWSI_CTL_AAK		0x04	/* Assert ACK */
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| 
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| /* Status values */
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| #define STAT_BUS_ERROR		0x00
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| #define STAT_START		0x08
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| #define STAT_REP_START		0x10
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| #define STAT_TXADDR_ACK		0x18
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| #define STAT_TXADDR_NAK		0x20
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| #define STAT_TXDATA_ACK		0x28
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| #define STAT_TXDATA_NAK		0x30
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| #define STAT_LOST_ARB_38	0x38
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| #define STAT_RXADDR_ACK		0x40
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| #define STAT_RXADDR_NAK		0x48
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| #define STAT_RXDATA_ACK		0x50
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| #define STAT_RXDATA_NAK		0x58
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| #define STAT_SLAVE_60		0x60
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| #define STAT_LOST_ARB_68	0x68
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| #define STAT_SLAVE_70		0x70
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| #define STAT_LOST_ARB_78	0x78
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| #define STAT_SLAVE_80		0x80
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| #define STAT_SLAVE_88		0x88
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| #define STAT_GENDATA_ACK	0x90
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| #define STAT_GENDATA_NAK	0x98
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| #define STAT_SLAVE_A0		0xA0
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| #define STAT_SLAVE_A8		0xA8
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| #define STAT_LOST_ARB_B0	0xB0
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| #define STAT_SLAVE_LOST		0xB8
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| #define STAT_SLAVE_NAK		0xC0
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| #define STAT_SLAVE_ACK		0xC8
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| #define STAT_AD2W_ACK		0xD0
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| #define STAT_AD2W_NAK		0xD8
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| #define STAT_IDLE		0xF8
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| 
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| /* TWSI_INT values */
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| #define TWSI_INT_ST_INT		BIT_ULL(0)
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| #define TWSI_INT_TS_INT		BIT_ULL(1)
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| #define TWSI_INT_CORE_INT	BIT_ULL(2)
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| #define TWSI_INT_ST_EN		BIT_ULL(4)
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| #define TWSI_INT_TS_EN		BIT_ULL(5)
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| #define TWSI_INT_CORE_EN	BIT_ULL(6)
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| #define TWSI_INT_SDA_OVR	BIT_ULL(8)
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| #define TWSI_INT_SCL_OVR	BIT_ULL(9)
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| #define TWSI_INT_SDA		BIT_ULL(10)
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| #define TWSI_INT_SCL		BIT_ULL(11)
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| 
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| #define I2C_OCTEON_EVENT_WAIT 80 /* microseconds */
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| 
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| /* Register offsets */
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| struct octeon_i2c_reg_offset {
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| 	unsigned int sw_twsi;
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| 	unsigned int twsi_int;
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| 	unsigned int sw_twsi_ext;
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| };
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| 
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| #define SW_TWSI(x)	(x->roff.sw_twsi)
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| #define TWSI_INT(x)	(x->roff.twsi_int)
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| #define SW_TWSI_EXT(x)	(x->roff.sw_twsi_ext)
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| 
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| struct octeon_i2c {
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| 	wait_queue_head_t queue;
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| 	struct i2c_adapter adap;
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| 	struct octeon_i2c_reg_offset roff;
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| 	struct clk *clk;
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| 	int irq;
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| 	int hlc_irq;		/* For cn7890 only */
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| 	u32 twsi_freq;
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| 	int sys_freq;
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| 	void __iomem *twsi_base;
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| 	struct device *dev;
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| 	bool hlc_enabled;
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| 	bool broken_irq_mode;
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| 	bool broken_irq_check;
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| 	void (*int_enable)(struct octeon_i2c *);
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| 	void (*int_disable)(struct octeon_i2c *);
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| 	void (*hlc_int_enable)(struct octeon_i2c *);
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| 	void (*hlc_int_disable)(struct octeon_i2c *);
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| 	atomic_t int_enable_cnt;
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| 	atomic_t hlc_int_enable_cnt;
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| 	struct i2c_smbus_alert_setup alert_data;
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| 	struct i2c_client *ara;
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| };
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| 
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| static inline void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
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| {
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| 	__raw_writeq(val, addr);
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| 	__raw_readq(addr);	/* wait for write to land */
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| }
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| 
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| /**
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|  * octeon_i2c_reg_write - write an I2C core register
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|  * @i2c: The struct octeon_i2c
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|  * @eop_reg: Register selector
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|  * @data: Value to be written
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|  *
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|  * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
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|  */
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| static inline void octeon_i2c_reg_write(struct octeon_i2c *i2c, u64 eop_reg, u8 data)
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| {
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| 	int tries = 1000;
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| 	u64 tmp;
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| 
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| 	__raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI(i2c));
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| 	do {
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| 		tmp = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
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| 		if (--tries < 0)
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| 			return;
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| 	} while ((tmp & SW_TWSI_V) != 0);
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| }
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| 
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| #define octeon_i2c_ctl_write(i2c, val)					\
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| 	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL, val)
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| #define octeon_i2c_data_write(i2c, val)					\
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| 	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_DATA, val)
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| 
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| /**
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|  * octeon_i2c_reg_read - read lower bits of an I2C core register
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|  * @i2c: The struct octeon_i2c
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|  * @eop_reg: Register selector
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|  *
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|  * Returns the data.
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|  *
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|  * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
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|  */
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| static inline int octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg,
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| 				      int *error)
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| {
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| 	int tries = 1000;
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| 	u64 tmp;
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| 
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| 	__raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI(i2c));
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| 	do {
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| 		tmp = __raw_readq(i2c->twsi_base + SW_TWSI(i2c));
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| 		if (--tries < 0) {
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| 			/* signal that the returned data is invalid */
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| 			if (error)
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| 				*error = -EIO;
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| 			return 0;
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| 		}
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| 	} while ((tmp & SW_TWSI_V) != 0);
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| 
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| 	return tmp & 0xFF;
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| }
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| 
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| #define octeon_i2c_ctl_read(i2c)					\
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| 	octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_CTL, NULL)
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| #define octeon_i2c_data_read(i2c, error)				\
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| 	octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_DATA, error)
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| #define octeon_i2c_stat_read(i2c)					\
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| 	octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT, NULL)
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| 
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| /**
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|  * octeon_i2c_read_int - read the TWSI_INT register
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|  * @i2c: The struct octeon_i2c
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|  *
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|  * Returns the value of the register.
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|  */
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| static inline u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
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| {
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| 	return __raw_readq(i2c->twsi_base + TWSI_INT(i2c));
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| }
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| 
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| /**
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|  * octeon_i2c_write_int - write the TWSI_INT register
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|  * @i2c: The struct octeon_i2c
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|  * @data: Value to be written
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|  */
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| static inline void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
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| {
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| 	octeon_i2c_writeq_flush(data, i2c->twsi_base + TWSI_INT(i2c));
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| }
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| 
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| /* Prototypes */
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| irqreturn_t octeon_i2c_isr(int irq, void *dev_id);
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| int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
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| int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c);
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| void octeon_i2c_set_clock(struct octeon_i2c *i2c);
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| extern struct i2c_bus_recovery_info octeon_i2c_recovery_info;
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