381 lines
9.0 KiB
C
381 lines
9.0 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2006-2007 PA Semi, Inc
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*
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* SMBus host driver for PA Semi PWRficient
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*/
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <linux/kernel.h>
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#include <linux/stddef.h>
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#include <linux/sched.h>
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#include <linux/i2c.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/io.h>
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#include "i2c-pasemi-core.h"
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/* Register offsets */
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#define REG_MTXFIFO 0x00
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#define REG_MRXFIFO 0x04
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#define REG_SMSTA 0x14
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#define REG_IMASK 0x18
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#define REG_CTL 0x1c
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#define REG_REV 0x28
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/* Register defs */
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#define MTXFIFO_READ 0x00000400
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#define MTXFIFO_STOP 0x00000200
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#define MTXFIFO_START 0x00000100
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#define MTXFIFO_DATA_M 0x000000ff
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#define MRXFIFO_EMPTY 0x00000100
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#define MRXFIFO_DATA_M 0x000000ff
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#define SMSTA_XEN 0x08000000
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#define SMSTA_MTN 0x00200000
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#define CTL_MRR 0x00000400
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#define CTL_MTR 0x00000200
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#define CTL_EN 0x00000800
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#define CTL_CLK_M 0x000000ff
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static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val)
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{
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dev_dbg(smbus->dev, "smbus write reg %x val %08x\n", reg, val);
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iowrite32(val, smbus->ioaddr + reg);
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}
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static inline int reg_read(struct pasemi_smbus *smbus, int reg)
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{
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int ret;
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ret = ioread32(smbus->ioaddr + reg);
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dev_dbg(smbus->dev, "smbus read reg %x val %08x\n", reg, ret);
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return ret;
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}
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#define TXFIFO_WR(smbus, reg) reg_write((smbus), REG_MTXFIFO, (reg))
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#define RXFIFO_RD(smbus) reg_read((smbus), REG_MRXFIFO)
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static void pasemi_reset(struct pasemi_smbus *smbus)
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{
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u32 val = (CTL_MTR | CTL_MRR | (smbus->clk_div & CTL_CLK_M));
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if (smbus->hw_rev >= 6)
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val |= CTL_EN;
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reg_write(smbus, REG_CTL, val);
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reinit_completion(&smbus->irq_completion);
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}
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static void pasemi_smb_clear(struct pasemi_smbus *smbus)
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{
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unsigned int status;
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status = reg_read(smbus, REG_SMSTA);
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reg_write(smbus, REG_SMSTA, status);
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}
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static int pasemi_smb_waitready(struct pasemi_smbus *smbus)
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{
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int timeout = 100;
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unsigned int status;
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if (smbus->use_irq) {
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reinit_completion(&smbus->irq_completion);
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reg_write(smbus, REG_IMASK, SMSTA_XEN | SMSTA_MTN);
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wait_for_completion_timeout(&smbus->irq_completion, msecs_to_jiffies(100));
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reg_write(smbus, REG_IMASK, 0);
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status = reg_read(smbus, REG_SMSTA);
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} else {
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status = reg_read(smbus, REG_SMSTA);
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while (!(status & SMSTA_XEN) && timeout--) {
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msleep(1);
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status = reg_read(smbus, REG_SMSTA);
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}
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}
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/* Got NACK? */
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if (status & SMSTA_MTN)
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return -ENXIO;
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if (timeout < 0) {
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dev_warn(smbus->dev, "Timeout, status 0x%08x\n", status);
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reg_write(smbus, REG_SMSTA, status);
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return -ETIME;
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}
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/* Clear XEN */
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reg_write(smbus, REG_SMSTA, SMSTA_XEN);
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return 0;
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}
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static int pasemi_i2c_xfer_msg(struct i2c_adapter *adapter,
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struct i2c_msg *msg, int stop)
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{
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struct pasemi_smbus *smbus = adapter->algo_data;
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int read, i, err;
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u32 rd;
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read = msg->flags & I2C_M_RD ? 1 : 0;
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TXFIFO_WR(smbus, MTXFIFO_START | i2c_8bit_addr_from_msg(msg));
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if (read) {
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TXFIFO_WR(smbus, msg->len | MTXFIFO_READ |
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(stop ? MTXFIFO_STOP : 0));
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err = pasemi_smb_waitready(smbus);
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if (err)
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goto reset_out;
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for (i = 0; i < msg->len; i++) {
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rd = RXFIFO_RD(smbus);
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if (rd & MRXFIFO_EMPTY) {
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err = -ENODATA;
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goto reset_out;
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}
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msg->buf[i] = rd & MRXFIFO_DATA_M;
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}
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} else {
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for (i = 0; i < msg->len - 1; i++)
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TXFIFO_WR(smbus, msg->buf[i]);
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TXFIFO_WR(smbus, msg->buf[msg->len-1] |
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(stop ? MTXFIFO_STOP : 0));
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if (stop) {
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err = pasemi_smb_waitready(smbus);
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if (err)
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goto reset_out;
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}
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}
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return 0;
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reset_out:
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pasemi_reset(smbus);
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return err;
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}
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static int pasemi_i2c_xfer(struct i2c_adapter *adapter,
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struct i2c_msg *msgs, int num)
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{
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struct pasemi_smbus *smbus = adapter->algo_data;
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int ret, i;
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pasemi_smb_clear(smbus);
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ret = 0;
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for (i = 0; i < num && !ret; i++)
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ret = pasemi_i2c_xfer_msg(adapter, &msgs[i], (i == (num - 1)));
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return ret ? ret : num;
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}
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static int pasemi_smb_xfer(struct i2c_adapter *adapter,
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u16 addr, unsigned short flags, char read_write, u8 command,
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int size, union i2c_smbus_data *data)
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{
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struct pasemi_smbus *smbus = adapter->algo_data;
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unsigned int rd;
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int read_flag, err;
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int len = 0, i;
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/* All our ops take 8-bit shifted addresses */
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addr <<= 1;
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read_flag = read_write == I2C_SMBUS_READ;
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pasemi_smb_clear(smbus);
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switch (size) {
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case I2C_SMBUS_QUICK:
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TXFIFO_WR(smbus, addr | read_flag | MTXFIFO_START |
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MTXFIFO_STOP);
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break;
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case I2C_SMBUS_BYTE:
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TXFIFO_WR(smbus, addr | read_flag | MTXFIFO_START);
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if (read_write)
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TXFIFO_WR(smbus, 1 | MTXFIFO_STOP | MTXFIFO_READ);
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else
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TXFIFO_WR(smbus, MTXFIFO_STOP | command);
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break;
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case I2C_SMBUS_BYTE_DATA:
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TXFIFO_WR(smbus, addr | MTXFIFO_START);
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TXFIFO_WR(smbus, command);
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if (read_write) {
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TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
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TXFIFO_WR(smbus, 1 | MTXFIFO_READ | MTXFIFO_STOP);
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} else {
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TXFIFO_WR(smbus, MTXFIFO_STOP | data->byte);
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}
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break;
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case I2C_SMBUS_WORD_DATA:
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TXFIFO_WR(smbus, addr | MTXFIFO_START);
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TXFIFO_WR(smbus, command);
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if (read_write) {
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TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
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TXFIFO_WR(smbus, 2 | MTXFIFO_READ | MTXFIFO_STOP);
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} else {
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TXFIFO_WR(smbus, data->word & MTXFIFO_DATA_M);
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TXFIFO_WR(smbus, MTXFIFO_STOP | (data->word >> 8));
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}
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break;
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case I2C_SMBUS_BLOCK_DATA:
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TXFIFO_WR(smbus, addr | MTXFIFO_START);
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TXFIFO_WR(smbus, command);
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if (read_write) {
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TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
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TXFIFO_WR(smbus, 1 | MTXFIFO_READ);
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rd = RXFIFO_RD(smbus);
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len = min_t(u8, (rd & MRXFIFO_DATA_M),
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I2C_SMBUS_BLOCK_MAX);
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TXFIFO_WR(smbus, len | MTXFIFO_READ |
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MTXFIFO_STOP);
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} else {
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len = min_t(u8, data->block[0], I2C_SMBUS_BLOCK_MAX);
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TXFIFO_WR(smbus, len);
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for (i = 1; i < len; i++)
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TXFIFO_WR(smbus, data->block[i]);
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TXFIFO_WR(smbus, data->block[len] | MTXFIFO_STOP);
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}
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break;
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case I2C_SMBUS_PROC_CALL:
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read_write = I2C_SMBUS_READ;
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TXFIFO_WR(smbus, addr | MTXFIFO_START);
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TXFIFO_WR(smbus, command);
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TXFIFO_WR(smbus, data->word & MTXFIFO_DATA_M);
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TXFIFO_WR(smbus, (data->word >> 8) & MTXFIFO_DATA_M);
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TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
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TXFIFO_WR(smbus, 2 | MTXFIFO_STOP | MTXFIFO_READ);
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break;
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case I2C_SMBUS_BLOCK_PROC_CALL:
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len = min_t(u8, data->block[0], I2C_SMBUS_BLOCK_MAX - 1);
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read_write = I2C_SMBUS_READ;
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TXFIFO_WR(smbus, addr | MTXFIFO_START);
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TXFIFO_WR(smbus, command);
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TXFIFO_WR(smbus, len);
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for (i = 1; i <= len; i++)
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TXFIFO_WR(smbus, data->block[i]);
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TXFIFO_WR(smbus, addr | I2C_SMBUS_READ);
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TXFIFO_WR(smbus, MTXFIFO_READ | 1);
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rd = RXFIFO_RD(smbus);
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len = min_t(u8, (rd & MRXFIFO_DATA_M),
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I2C_SMBUS_BLOCK_MAX - len);
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TXFIFO_WR(smbus, len | MTXFIFO_READ | MTXFIFO_STOP);
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break;
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default:
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dev_warn(&adapter->dev, "Unsupported transaction %d\n", size);
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return -EINVAL;
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}
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err = pasemi_smb_waitready(smbus);
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if (err)
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goto reset_out;
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if (read_write == I2C_SMBUS_WRITE)
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return 0;
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switch (size) {
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case I2C_SMBUS_BYTE:
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case I2C_SMBUS_BYTE_DATA:
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rd = RXFIFO_RD(smbus);
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if (rd & MRXFIFO_EMPTY) {
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err = -ENODATA;
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goto reset_out;
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}
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data->byte = rd & MRXFIFO_DATA_M;
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break;
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case I2C_SMBUS_WORD_DATA:
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case I2C_SMBUS_PROC_CALL:
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rd = RXFIFO_RD(smbus);
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if (rd & MRXFIFO_EMPTY) {
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err = -ENODATA;
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goto reset_out;
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}
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data->word = rd & MRXFIFO_DATA_M;
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rd = RXFIFO_RD(smbus);
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if (rd & MRXFIFO_EMPTY) {
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err = -ENODATA;
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goto reset_out;
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}
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data->word |= (rd & MRXFIFO_DATA_M) << 8;
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break;
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case I2C_SMBUS_BLOCK_DATA:
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case I2C_SMBUS_BLOCK_PROC_CALL:
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data->block[0] = len;
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for (i = 1; i <= len; i ++) {
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rd = RXFIFO_RD(smbus);
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if (rd & MRXFIFO_EMPTY) {
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err = -ENODATA;
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goto reset_out;
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}
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data->block[i] = rd & MRXFIFO_DATA_M;
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}
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break;
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}
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return 0;
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reset_out:
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pasemi_reset(smbus);
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return err;
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}
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static u32 pasemi_smb_func(struct i2c_adapter *adapter)
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{
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return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
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I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
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I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL |
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I2C_FUNC_SMBUS_BLOCK_PROC_CALL | I2C_FUNC_I2C;
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}
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static const struct i2c_algorithm smbus_algorithm = {
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.master_xfer = pasemi_i2c_xfer,
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.smbus_xfer = pasemi_smb_xfer,
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.functionality = pasemi_smb_func,
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};
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int pasemi_i2c_common_probe(struct pasemi_smbus *smbus)
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{
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int error;
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smbus->adapter.owner = THIS_MODULE;
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snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
|
||
|
|
"PA Semi SMBus adapter (%s)", dev_name(smbus->dev));
|
||
|
|
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;
|
||
|
|
smbus->use_irq = 0;
|
||
|
|
init_completion(&smbus->irq_completion);
|
||
|
|
|
||
|
|
if (smbus->hw_rev != PASEMI_HW_REV_PCI)
|
||
|
|
smbus->hw_rev = reg_read(smbus, REG_REV);
|
||
|
|
|
||
|
|
reg_write(smbus, REG_IMASK, 0);
|
||
|
|
|
||
|
|
pasemi_reset(smbus);
|
||
|
|
|
||
|
|
error = devm_i2c_add_adapter(smbus->dev, &smbus->adapter);
|
||
|
|
if (error)
|
||
|
|
return error;
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
irqreturn_t pasemi_irq_handler(int irq, void *dev_id)
|
||
|
|
{
|
||
|
|
struct pasemi_smbus *smbus = dev_id;
|
||
|
|
|
||
|
|
reg_write(smbus, REG_IMASK, 0);
|
||
|
|
complete(&smbus->irq_completion);
|
||
|
|
return IRQ_HANDLED;
|
||
|
|
}
|