| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (C) 2006-2007 PA Semi, Inc |
| * |
| * SMBus host driver for PA Semi PWRficient |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/pci.h> |
| #include <linux/kernel.h> |
| #include <linux/stddef.h> |
| #include <linux/sched.h> |
| #include <linux/i2c.h> |
| #include <linux/delay.h> |
| #include <linux/slab.h> |
| #include <linux/io.h> |
| |
| #include "i2c-pasemi-core.h" |
| |
| /* Register offsets */ |
| #define REG_MTXFIFO 0x00 |
| #define REG_MRXFIFO 0x04 |
| #define REG_SMSTA 0x14 |
| #define REG_CTL 0x1c |
| #define REG_REV 0x28 |
| |
| /* Register defs */ |
| #define MTXFIFO_READ 0x00000400 |
| #define MTXFIFO_STOP 0x00000200 |
| #define MTXFIFO_START 0x00000100 |
| #define MTXFIFO_DATA_M 0x000000ff |
| |
| #define MRXFIFO_EMPTY 0x00000100 |
| #define MRXFIFO_DATA_M 0x000000ff |
| |
| #define SMSTA_XEN 0x08000000 |
| #define SMSTA_MTN 0x00200000 |
| |
| #define CTL_MRR 0x00000400 |
| #define CTL_MTR 0x00000200 |
| #define CTL_EN 0x00000800 |
| #define CTL_CLK_M 0x000000ff |
| |
| static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val) |
| { |
| dev_dbg(smbus->dev, "smbus write reg %x val %08x\n", reg, val); |
| iowrite32(val, smbus->ioaddr + reg); |
| } |
| |
| static inline int reg_read(struct pasemi_smbus *smbus, int reg) |
| { |
| int ret; |
| ret = ioread32(smbus->ioaddr + reg); |
| dev_dbg(smbus->dev, "smbus read reg %x val %08x\n", reg, ret); |
| return ret; |
| } |
| |
| #define TXFIFO_WR(smbus, reg) reg_write((smbus), REG_MTXFIFO, (reg)) |
| #define RXFIFO_RD(smbus) reg_read((smbus), REG_MRXFIFO) |
| |
| static void pasemi_reset(struct pasemi_smbus *smbus) |
| { |
| u32 val = (CTL_MTR | CTL_MRR | (smbus->clk_div & CTL_CLK_M)); |
| |
| if (smbus->hw_rev >= 6) |
| val |= CTL_EN; |
| |
| reg_write(smbus, REG_CTL, val); |
| } |
| |
| static void pasemi_smb_clear(struct pasemi_smbus *smbus) |
| { |
| unsigned int status; |
| |
| status = reg_read(smbus, REG_SMSTA); |
| reg_write(smbus, REG_SMSTA, status); |
| } |
| |
| static int pasemi_smb_waitready(struct pasemi_smbus *smbus) |
| { |
| int timeout = 10; |
| unsigned int status; |
| |
| status = reg_read(smbus, REG_SMSTA); |
| |
| while (!(status & SMSTA_XEN) && timeout--) { |
| msleep(1); |
| status = reg_read(smbus, REG_SMSTA); |
| } |
| |
| /* Got NACK? */ |
| if (status & SMSTA_MTN) |
| return -ENXIO; |
| |
| if (timeout < 0) { |
| dev_warn(smbus->dev, "Timeout, status 0x%08x\n", status); |
| reg_write(smbus, REG_SMSTA, status); |
| return -ETIME; |
| } |
| |
| /* Clear XEN */ |
| reg_write(smbus, REG_SMSTA, SMSTA_XEN); |
| |
| return 0; |
| } |
| |
| static int pasemi_i2c_xfer_msg(struct i2c_adapter *adapter, |
| struct i2c_msg *msg, int stop) |
| { |
| struct pasemi_smbus *smbus = adapter->algo_data; |
| int read, i, err; |
| u32 rd; |
| |
| read = msg->flags & I2C_M_RD ? 1 : 0; |
| |
| TXFIFO_WR(smbus, MTXFIFO_START | i2c_8bit_addr_from_msg(msg)); |
| |
| if (read) { |
| TXFIFO_WR(smbus, msg->len | MTXFIFO_READ | |
| (stop ? MTXFIFO_STOP : 0)); |
| |
| err = pasemi_smb_waitready(smbus); |
| if (err) |
| goto reset_out; |
| |
| for (i = 0; i < msg->len; i++) { |
| rd = RXFIFO_RD(smbus); |
| if (rd & MRXFIFO_EMPTY) { |
| err = -ENODATA; |
| goto reset_out; |
| } |
| msg->buf[i] = rd & MRXFIFO_DATA_M; |
| } |
| } else { |
| for (i = 0; i < msg->len - 1; i++) |
| TXFIFO_WR(smbus, msg->buf[i]); |
| |
| TXFIFO_WR(smbus, msg->buf[msg->len-1] | |
| (stop ? MTXFIFO_STOP : 0)); |
| } |
| |
| return 0; |
| |
| reset_out: |
| pasemi_reset(smbus); |
| return err; |
| } |
| |
| static int pasemi_i2c_xfer(struct i2c_adapter *adapter, |
| struct i2c_msg *msgs, int num) |
| { |
| struct pasemi_smbus *smbus = adapter->algo_data; |
| int ret, i; |
| |
| pasemi_smb_clear(smbus); |
| |
| ret = 0; |
| |
| for (i = 0; i < num && !ret; i++) |
| ret = pasemi_i2c_xfer_msg(adapter, &msgs[i], (i == (num - 1))); |
| |
| return ret ? ret : num; |
| } |
| |
| static int pasemi_smb_xfer(struct i2c_adapter *adapter, |
| u16 addr, unsigned short flags, char read_write, u8 command, |
| int size, union i2c_smbus_data *data) |
| { |
| struct pasemi_smbus *smbus = adapter->algo_data; |
| unsigned int rd; |
| int read_flag, err; |
| int len = 0, i; |
| |
| /* All our ops take 8-bit shifted addresses */ |
| addr <<= 1; |
| read_flag = read_write == I2C_SMBUS_READ; |
| |
| pasemi_smb_clear(smbus); |
| |
| switch (size) { |
| case I2C_SMBUS_QUICK: |
| TXFIFO_WR(smbus, addr | read_flag | MTXFIFO_START | |
| MTXFIFO_STOP); |
| break; |
| case I2C_SMBUS_BYTE: |
| TXFIFO_WR(smbus, addr | read_flag | MTXFIFO_START); |
| if (read_write) |
| TXFIFO_WR(smbus, 1 | MTXFIFO_STOP | MTXFIFO_READ); |
| else |
| TXFIFO_WR(smbus, MTXFIFO_STOP | command); |
| break; |
| case I2C_SMBUS_BYTE_DATA: |
| TXFIFO_WR(smbus, addr | MTXFIFO_START); |
| TXFIFO_WR(smbus, command); |
| if (read_write) { |
| TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START); |
| TXFIFO_WR(smbus, 1 | MTXFIFO_READ | MTXFIFO_STOP); |
| } else { |
| TXFIFO_WR(smbus, MTXFIFO_STOP | data->byte); |
| } |
| break; |
| case I2C_SMBUS_WORD_DATA: |
| TXFIFO_WR(smbus, addr | MTXFIFO_START); |
| TXFIFO_WR(smbus, command); |
| if (read_write) { |
| TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START); |
| TXFIFO_WR(smbus, 2 | MTXFIFO_READ | MTXFIFO_STOP); |
| } else { |
| TXFIFO_WR(smbus, data->word & MTXFIFO_DATA_M); |
| TXFIFO_WR(smbus, MTXFIFO_STOP | (data->word >> 8)); |
| } |
| break; |
| case I2C_SMBUS_BLOCK_DATA: |
| TXFIFO_WR(smbus, addr | MTXFIFO_START); |
| TXFIFO_WR(smbus, command); |
| if (read_write) { |
| TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START); |
| TXFIFO_WR(smbus, 1 | MTXFIFO_READ); |
| rd = RXFIFO_RD(smbus); |
| len = min_t(u8, (rd & MRXFIFO_DATA_M), |
| I2C_SMBUS_BLOCK_MAX); |
| TXFIFO_WR(smbus, len | MTXFIFO_READ | |
| MTXFIFO_STOP); |
| } else { |
| len = min_t(u8, data->block[0], I2C_SMBUS_BLOCK_MAX); |
| TXFIFO_WR(smbus, len); |
| for (i = 1; i < len; i++) |
| TXFIFO_WR(smbus, data->block[i]); |
| TXFIFO_WR(smbus, data->block[len] | MTXFIFO_STOP); |
| } |
| break; |
| case I2C_SMBUS_PROC_CALL: |
| read_write = I2C_SMBUS_READ; |
| TXFIFO_WR(smbus, addr | MTXFIFO_START); |
| TXFIFO_WR(smbus, command); |
| TXFIFO_WR(smbus, data->word & MTXFIFO_DATA_M); |
| TXFIFO_WR(smbus, (data->word >> 8) & MTXFIFO_DATA_M); |
| TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START); |
| TXFIFO_WR(smbus, 2 | MTXFIFO_STOP | MTXFIFO_READ); |
| break; |
| case I2C_SMBUS_BLOCK_PROC_CALL: |
| len = min_t(u8, data->block[0], I2C_SMBUS_BLOCK_MAX - 1); |
| read_write = I2C_SMBUS_READ; |
| TXFIFO_WR(smbus, addr | MTXFIFO_START); |
| TXFIFO_WR(smbus, command); |
| TXFIFO_WR(smbus, len); |
| for (i = 1; i <= len; i++) |
| TXFIFO_WR(smbus, data->block[i]); |
| TXFIFO_WR(smbus, addr | I2C_SMBUS_READ); |
| TXFIFO_WR(smbus, MTXFIFO_READ | 1); |
| rd = RXFIFO_RD(smbus); |
| len = min_t(u8, (rd & MRXFIFO_DATA_M), |
| I2C_SMBUS_BLOCK_MAX - len); |
| TXFIFO_WR(smbus, len | MTXFIFO_READ | MTXFIFO_STOP); |
| break; |
| |
| default: |
| dev_warn(&adapter->dev, "Unsupported transaction %d\n", size); |
| return -EINVAL; |
| } |
| |
| err = pasemi_smb_waitready(smbus); |
| if (err) |
| goto reset_out; |
| |
| if (read_write == I2C_SMBUS_WRITE) |
| return 0; |
| |
| switch (size) { |
| case I2C_SMBUS_BYTE: |
| case I2C_SMBUS_BYTE_DATA: |
| rd = RXFIFO_RD(smbus); |
| if (rd & MRXFIFO_EMPTY) { |
| err = -ENODATA; |
| goto reset_out; |
| } |
| data->byte = rd & MRXFIFO_DATA_M; |
| break; |
| case I2C_SMBUS_WORD_DATA: |
| case I2C_SMBUS_PROC_CALL: |
| rd = RXFIFO_RD(smbus); |
| if (rd & MRXFIFO_EMPTY) { |
| err = -ENODATA; |
| goto reset_out; |
| } |
| data->word = rd & MRXFIFO_DATA_M; |
| rd = RXFIFO_RD(smbus); |
| if (rd & MRXFIFO_EMPTY) { |
| err = -ENODATA; |
| goto reset_out; |
| } |
| data->word |= (rd & MRXFIFO_DATA_M) << 8; |
| break; |
| case I2C_SMBUS_BLOCK_DATA: |
| case I2C_SMBUS_BLOCK_PROC_CALL: |
| data->block[0] = len; |
| for (i = 1; i <= len; i ++) { |
| rd = RXFIFO_RD(smbus); |
| if (rd & MRXFIFO_EMPTY) { |
| err = -ENODATA; |
| goto reset_out; |
| } |
| data->block[i] = rd & MRXFIFO_DATA_M; |
| } |
| break; |
| } |
| |
| return 0; |
| |
| reset_out: |
| pasemi_reset(smbus); |
| return err; |
| } |
| |
| static u32 pasemi_smb_func(struct i2c_adapter *adapter) |
| { |
| return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | |
| I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | |
| I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL | |
| I2C_FUNC_SMBUS_BLOCK_PROC_CALL | I2C_FUNC_I2C; |
| } |
| |
| static const struct i2c_algorithm smbus_algorithm = { |
| .master_xfer = pasemi_i2c_xfer, |
| .smbus_xfer = pasemi_smb_xfer, |
| .functionality = pasemi_smb_func, |
| }; |
| |
| int pasemi_i2c_common_probe(struct pasemi_smbus *smbus) |
| { |
| int error; |
| |
| smbus->adapter.owner = THIS_MODULE; |
| snprintf(smbus->adapter.name, sizeof(smbus->adapter.name), |
| "PA Semi SMBus adapter (%s)", dev_name(smbus->dev)); |
| smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD; |
| smbus->adapter.algo = &smbus_algorithm; |
| smbus->adapter.algo_data = smbus; |
| |
| /* set up the sysfs linkage to our parent device */ |
| smbus->adapter.dev.parent = smbus->dev; |
| |
| if (smbus->hw_rev != PASEMI_HW_REV_PCI) |
| smbus->hw_rev = reg_read(smbus, REG_REV); |
| |
| pasemi_reset(smbus); |
| |
| error = devm_i2c_add_adapter(smbus->dev, &smbus->adapter); |
| if (error) |
| return error; |
| |
| return 0; |
| } |
