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