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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C) 2004 Steven J. Hill4 * Copyright (C) 2001,2002,2003 Broadcom Corporation5 * Copyright (C) 1995-2000 Simon G. Vogl6 */7 8#include <linux/kernel.h>9#include <linux/module.h>10#include <linux/init.h>11#include <linux/i2c.h>12#include <linux/io.h>13#include <asm/sibyte/sb1250_regs.h>14#include <asm/sibyte/sb1250_smbus.h>15 16 17struct i2c_algo_sibyte_data {18 void *data; /* private data */19 int bus; /* which bus */20 void *reg_base; /* CSR base */21};22 23/* ----- global defines ----------------------------------------------- */24#define SMB_CSR(a,r) ((long)(a->reg_base + r))25 26 27static int smbus_xfer(struct i2c_adapter *i2c_adap, u16 addr,28 unsigned short flags, char read_write,29 u8 command, int size, union i2c_smbus_data * data)30{31 struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;32 int data_bytes = 0;33 int error;34 35 while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)36 ;37 38 switch (size) {39 case I2C_SMBUS_QUICK:40 csr_out32((V_SMB_ADDR(addr) |41 (read_write == I2C_SMBUS_READ ? M_SMB_QDATA : 0) |42 V_SMB_TT_QUICKCMD), SMB_CSR(adap, R_SMB_START));43 break;44 case I2C_SMBUS_BYTE:45 if (read_write == I2C_SMBUS_READ) {46 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_RD1BYTE),47 SMB_CSR(adap, R_SMB_START));48 data_bytes = 1;49 } else {50 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));51 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR1BYTE),52 SMB_CSR(adap, R_SMB_START));53 }54 break;55 case I2C_SMBUS_BYTE_DATA:56 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));57 if (read_write == I2C_SMBUS_READ) {58 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD1BYTE),59 SMB_CSR(adap, R_SMB_START));60 data_bytes = 1;61 } else {62 csr_out32(V_SMB_LB(data->byte),63 SMB_CSR(adap, R_SMB_DATA));64 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),65 SMB_CSR(adap, R_SMB_START));66 }67 break;68 case I2C_SMBUS_WORD_DATA:69 csr_out32(V_SMB_CMD(command), SMB_CSR(adap, R_SMB_CMD));70 if (read_write == I2C_SMBUS_READ) {71 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_CMD_RD2BYTE),72 SMB_CSR(adap, R_SMB_START));73 data_bytes = 2;74 } else {75 csr_out32(V_SMB_LB(data->word & 0xff),76 SMB_CSR(adap, R_SMB_DATA));77 csr_out32(V_SMB_MB(data->word >> 8),78 SMB_CSR(adap, R_SMB_DATA));79 csr_out32((V_SMB_ADDR(addr) | V_SMB_TT_WR2BYTE),80 SMB_CSR(adap, R_SMB_START));81 }82 break;83 default:84 return -EOPNOTSUPP;85 }86 87 while (csr_in32(SMB_CSR(adap, R_SMB_STATUS)) & M_SMB_BUSY)88 ;89 90 error = csr_in32(SMB_CSR(adap, R_SMB_STATUS));91 if (error & M_SMB_ERROR) {92 /* Clear error bit by writing a 1 */93 csr_out32(M_SMB_ERROR, SMB_CSR(adap, R_SMB_STATUS));94 return (error & M_SMB_ERROR_TYPE) ? -EIO : -ENXIO;95 }96 97 if (data_bytes == 1)98 data->byte = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xff;99 if (data_bytes == 2)100 data->word = csr_in32(SMB_CSR(adap, R_SMB_DATA)) & 0xffff;101 102 return 0;103}104 105static u32 bit_func(struct i2c_adapter *adap)106{107 return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |108 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA);109}110 111 112/* -----exported algorithm data: ------------------------------------- */113 114static const struct i2c_algorithm i2c_sibyte_algo = {115 .smbus_xfer = smbus_xfer,116 .functionality = bit_func,117};118 119/*120 * registering functions to load algorithms at runtime121 */122static int __init i2c_sibyte_add_bus(struct i2c_adapter *i2c_adap, int speed)123{124 struct i2c_algo_sibyte_data *adap = i2c_adap->algo_data;125 126 /* Register new adapter to i2c module... */127 i2c_adap->algo = &i2c_sibyte_algo;128 129 /* Set the requested frequency. */130 csr_out32(speed, SMB_CSR(adap,R_SMB_FREQ));131 csr_out32(0, SMB_CSR(adap,R_SMB_CONTROL));132 133 return i2c_add_numbered_adapter(i2c_adap);134}135 136 137static struct i2c_algo_sibyte_data sibyte_board_data[2] = {138 { NULL, 0, (void *) (CKSEG1+A_SMB_BASE(0)) },139 { NULL, 1, (void *) (CKSEG1+A_SMB_BASE(1)) }140};141 142static struct i2c_adapter sibyte_board_adapter[2] = {143 {144 .owner = THIS_MODULE,145 .class = I2C_CLASS_HWMON,146 .algo = NULL,147 .algo_data = &sibyte_board_data[0],148 .nr = 0,149 .name = "SiByte SMBus 0",150 },151 {152 .owner = THIS_MODULE,153 .class = I2C_CLASS_HWMON,154 .algo = NULL,155 .algo_data = &sibyte_board_data[1],156 .nr = 1,157 .name = "SiByte SMBus 1",158 },159};160 161static int __init i2c_sibyte_init(void)162{163 pr_info("i2c-sibyte: i2c SMBus adapter module for SiByte board\n");164 if (i2c_sibyte_add_bus(&sibyte_board_adapter[0], K_SMB_FREQ_100KHZ) < 0)165 return -ENODEV;166 if (i2c_sibyte_add_bus(&sibyte_board_adapter[1],167 K_SMB_FREQ_400KHZ) < 0) {168 i2c_del_adapter(&sibyte_board_adapter[0]);169 return -ENODEV;170 }171 return 0;172}173 174static void __exit i2c_sibyte_exit(void)175{176 i2c_del_adapter(&sibyte_board_adapter[0]);177 i2c_del_adapter(&sibyte_board_adapter[1]);178}179 180module_init(i2c_sibyte_init);181module_exit(i2c_sibyte_exit);182 183MODULE_AUTHOR("Kip Walker (Broadcom Corp.)");184MODULE_AUTHOR("Steven J. Hill <sjhill@realitydiluted.com>");185MODULE_DESCRIPTION("SMBus adapter routines for SiByte boards");186MODULE_LICENSE("GPL");187