1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * Copyright (C) 2005-2006 Micronas USA Inc. 4 */ 5 6#include <linux/module.h> 7#include <linux/delay.h> 8#include <linux/sched.h> 9#include <linux/list.h> 10#include <linux/unistd.h> 11#include <linux/time.h> 12#include <linux/device.h> 13#include <linux/i2c.h> 14#include <linux/mutex.h> 15#include <linux/uaccess.h> 16 17#include "go7007-priv.h" 18 19/********************* Driver for on-board I2C adapter *********************/ 20 21/* #define GO7007_I2C_DEBUG */ 22 23#define SPI_I2C_ADDR_BASE 0x1400 24#define STATUS_REG_ADDR (SPI_I2C_ADDR_BASE + 0x2) 25#define I2C_CTRL_REG_ADDR (SPI_I2C_ADDR_BASE + 0x6) 26#define I2C_DEV_UP_ADDR_REG_ADDR (SPI_I2C_ADDR_BASE + 0x7) 27#define I2C_LO_ADDR_REG_ADDR (SPI_I2C_ADDR_BASE + 0x8) 28#define I2C_DATA_REG_ADDR (SPI_I2C_ADDR_BASE + 0x9) 29#define I2C_CLKFREQ_REG_ADDR (SPI_I2C_ADDR_BASE + 0xa) 30 31#define I2C_STATE_MASK 0x0007 32#define I2C_READ_READY_MASK 0x0008 33 34/* There is only one I2C port on the TW2804 that feeds all four GO7007 VIPs 35 * on the Adlink PCI-MPG24, so access is shared between all of them. */ 36static DEFINE_MUTEX(adlink_mpg24_i2c_lock); 37 38static int go7007_i2c_xfer(struct go7007 *go, u16 addr, int read, 39 u16 command, int flags, u8 *data) 40{ 41 int i, ret = -EIO; 42 u16 val; 43 44 if (go->status == STATUS_SHUTDOWN) 45 return -ENODEV; 46 47#ifdef GO7007_I2C_DEBUG 48 if (read) 49 dev_dbg(go->dev, "go7007-i2c: reading 0x%02x on 0x%02x\n", 50 command, addr); 51 else 52 dev_dbg(go->dev, 53 "go7007-i2c: writing 0x%02x to 0x%02x on 0x%02x\n", 54 *data, command, addr); 55#endif 56 57 mutex_lock(&go->hw_lock); 58 59 if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) { 60 /* Bridge the I2C port on this GO7007 to the shared bus */ 61 mutex_lock(&adlink_mpg24_i2c_lock); 62 go7007_write_addr(go, 0x3c82, 0x0020); 63 } 64 65 /* Wait for I2C adapter to be ready */ 66 for (i = 0; i < 10; ++i) { 67 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0) 68 goto i2c_done; 69 if (!(val & I2C_STATE_MASK)) 70 break; 71 msleep(100); 72 } 73 if (i == 10) { 74 dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n"); 75 goto i2c_done; 76 } 77 78 /* Set target register (command) */ 79 go7007_write_addr(go, I2C_CTRL_REG_ADDR, flags); 80 go7007_write_addr(go, I2C_LO_ADDR_REG_ADDR, command); 81 82 /* If we're writing, send the data and target address and we're done */ 83 if (!read) { 84 go7007_write_addr(go, I2C_DATA_REG_ADDR, *data); 85 go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR, 86 (addr << 9) | (command >> 8)); 87 ret = 0; 88 goto i2c_done; 89 } 90 91 /* Otherwise, we're reading. First clear i2c_rx_data_rdy. */ 92 if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0) 93 goto i2c_done; 94 95 /* Send the target address plus read flag */ 96 go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR, 97 (addr << 9) | 0x0100 | (command >> 8)); 98 99 /* Wait for i2c_rx_data_rdy */ 100 for (i = 0; i < 10; ++i) { 101 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0) 102 goto i2c_done; 103 if (val & I2C_READ_READY_MASK) 104 break; 105 msleep(100); 106 } 107 if (i == 10) { 108 dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n"); 109 goto i2c_done; 110 } 111 112 /* Retrieve the read byte */ 113 if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0) 114 goto i2c_done; 115 *data = val; 116 ret = 0; 117 118i2c_done: 119 if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) { 120 /* Isolate the I2C port on this GO7007 from the shared bus */ 121 go7007_write_addr(go, 0x3c82, 0x0000); 122 mutex_unlock(&adlink_mpg24_i2c_lock); 123 } 124 mutex_unlock(&go->hw_lock); 125 return ret; 126} 127 128static int go7007_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 129 unsigned short flags, char read_write, 130 u8 command, int size, union i2c_smbus_data *data) 131{ 132 struct go7007 *go = i2c_get_adapdata(adapter); 133 134 if (size != I2C_SMBUS_BYTE_DATA) 135 return -EIO; 136 return go7007_i2c_xfer(go, addr, read_write == I2C_SMBUS_READ, command, 137 flags & I2C_CLIENT_SCCB ? 0x10 : 0x00, &data->byte); 138} 139 140/* VERY LIMITED I2C master xfer function -- only needed because the 141 * SMBus functions only support 8-bit commands and the SAA7135 uses 142 * 16-bit commands. The I2C interface on the GO7007, as limited as 143 * it is, does support this mode. */ 144 145static int go7007_i2c_master_xfer(struct i2c_adapter *adapter, 146 struct i2c_msg msgs[], int num) 147{ 148 struct go7007 *go = i2c_get_adapdata(adapter); 149 int i; 150 151 for (i = 0; i < num; ++i) { 152 /* We can only do two things here -- write three bytes, or 153 * write two bytes and read one byte. */ 154 if (msgs[i].len == 2) { 155 if (i + 1 == num || msgs[i].addr != msgs[i + 1].addr || 156 (msgs[i].flags & I2C_M_RD) || 157 !(msgs[i + 1].flags & I2C_M_RD) || 158 msgs[i + 1].len != 1) 159 return -EIO; 160 if (go7007_i2c_xfer(go, msgs[i].addr, 1, 161 (msgs[i].buf[0] << 8) | msgs[i].buf[1], 162 0x01, &msgs[i + 1].buf[0]) < 0) 163 return -EIO; 164 ++i; 165 } else if (msgs[i].len == 3) { 166 if (msgs[i].flags & I2C_M_RD) 167 return -EIO; 168 if (go7007_i2c_xfer(go, msgs[i].addr, 0, 169 (msgs[i].buf[0] << 8) | msgs[i].buf[1], 170 0x01, &msgs[i].buf[2]) < 0) 171 return -EIO; 172 } else 173 return -EIO; 174 } 175 176 return num; 177} 178 179static u32 go7007_functionality(struct i2c_adapter *adapter) 180{ 181 return I2C_FUNC_SMBUS_BYTE_DATA; 182} 183 184static const struct i2c_algorithm go7007_algo = { 185 .smbus_xfer = go7007_smbus_xfer, 186 .master_xfer = go7007_i2c_master_xfer, 187 .functionality = go7007_functionality, 188}; 189 190static struct i2c_adapter go7007_adap_templ = { 191 .owner = THIS_MODULE, 192 .name = "WIS GO7007SB", 193 .algo = &go7007_algo, 194}; 195 196int go7007_i2c_init(struct go7007 *go) 197{ 198 memcpy(&go->i2c_adapter, &go7007_adap_templ, 199 sizeof(go7007_adap_templ)); 200 go->i2c_adapter.dev.parent = go->dev; 201 i2c_set_adapdata(&go->i2c_adapter, go); 202 if (i2c_add_adapter(&go->i2c_adapter) < 0) { 203 dev_err(go->dev, 204 "go7007-i2c: error: i2c_add_adapter failed\n"); 205 return -1; 206 } 207 return 0; 208} 209