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. */ 36 static DEFINE_MUTEX(adlink_mpg24_i2c_mutex); 37 38 static inline void adlink_mpg24_i2c_lock(struct go7007 *go) 39 { 40 /* Bridge the I2C port on this GO7007 to the shared bus */ 41 mutex_lock(&adlink_mpg24_i2c_mutex); 42 go7007_write_addr(go, 0x3c82, 0x0020); 43 } 44 45 static inline void adlink_mpg24_i2c_unlock(struct go7007 *go) 46 { 47 /* Isolate the I2C port on this GO7007 from the shared bus */ 48 go7007_write_addr(go, 0x3c82, 0x0000); 49 mutex_unlock(&adlink_mpg24_i2c_mutex); 50 } 51 52 static int go7007_i2c_xfer(struct go7007 *go, u16 addr, int read, 53 u16 command, int flags, u8 *data) 54 { 55 int i, ret = -EIO; 56 u16 val; 57 58 if (go->status == STATUS_SHUTDOWN) 59 return -ENODEV; 60 61 #ifdef GO7007_I2C_DEBUG 62 if (read) 63 dev_dbg(go->dev, "go7007-i2c: reading 0x%02x on 0x%02x\n", 64 command, addr); 65 else 66 dev_dbg(go->dev, 67 "go7007-i2c: writing 0x%02x to 0x%02x on 0x%02x\n", 68 *data, command, addr); 69 #endif 70 71 mutex_lock(&go->hw_lock); 72 73 if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) 74 adlink_mpg24_i2c_lock(go); 75 76 /* Wait for I2C adapter to be ready */ 77 for (i = 0; i < 10; ++i) { 78 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0) 79 goto i2c_done; 80 if (!(val & I2C_STATE_MASK)) 81 break; 82 msleep(100); 83 } 84 if (i == 10) { 85 dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n"); 86 goto i2c_done; 87 } 88 89 /* Set target register (command) */ 90 go7007_write_addr(go, I2C_CTRL_REG_ADDR, flags); 91 go7007_write_addr(go, I2C_LO_ADDR_REG_ADDR, command); 92 93 /* If we're writing, send the data and target address and we're done */ 94 if (!read) { 95 go7007_write_addr(go, I2C_DATA_REG_ADDR, *data); 96 go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR, 97 (addr << 9) | (command >> 8)); 98 ret = 0; 99 goto i2c_done; 100 } 101 102 /* Otherwise, we're reading. First clear i2c_rx_data_rdy. */ 103 if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0) 104 goto i2c_done; 105 106 /* Send the target address plus read flag */ 107 go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR, 108 (addr << 9) | 0x0100 | (command >> 8)); 109 110 /* Wait for i2c_rx_data_rdy */ 111 for (i = 0; i < 10; ++i) { 112 if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0) 113 goto i2c_done; 114 if (val & I2C_READ_READY_MASK) 115 break; 116 msleep(100); 117 } 118 if (i == 10) { 119 dev_err(go->dev, "go7007-i2c: I2C adapter is hung\n"); 120 goto i2c_done; 121 } 122 123 /* Retrieve the read byte */ 124 if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0) 125 goto i2c_done; 126 *data = val; 127 ret = 0; 128 129 i2c_done: 130 if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) 131 adlink_mpg24_i2c_unlock(go); 132 mutex_unlock(&go->hw_lock); 133 return ret; 134 } 135 136 static int go7007_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 137 unsigned short flags, char read_write, 138 u8 command, int size, union i2c_smbus_data *data) 139 { 140 struct go7007 *go = i2c_get_adapdata(adapter); 141 142 if (size != I2C_SMBUS_BYTE_DATA) 143 return -EIO; 144 return go7007_i2c_xfer(go, addr, read_write == I2C_SMBUS_READ, command, 145 flags & I2C_CLIENT_SCCB ? 0x10 : 0x00, &data->byte); 146 } 147 148 /* VERY LIMITED I2C master xfer function -- only needed because the 149 * SMBus functions only support 8-bit commands and the SAA7135 uses 150 * 16-bit commands. The I2C interface on the GO7007, as limited as 151 * it is, does support this mode. */ 152 153 static int go7007_i2c_master_xfer(struct i2c_adapter *adapter, 154 struct i2c_msg msgs[], int num) 155 { 156 struct go7007 *go = i2c_get_adapdata(adapter); 157 int i; 158 159 for (i = 0; i < num; ++i) { 160 /* We can only do two things here -- write three bytes, or 161 * write two bytes and read one byte. */ 162 if (msgs[i].len == 2) { 163 if (i + 1 == num || msgs[i].addr != msgs[i + 1].addr || 164 (msgs[i].flags & I2C_M_RD) || 165 !(msgs[i + 1].flags & I2C_M_RD) || 166 msgs[i + 1].len != 1) 167 return -EIO; 168 if (go7007_i2c_xfer(go, msgs[i].addr, 1, 169 (msgs[i].buf[0] << 8) | msgs[i].buf[1], 170 0x01, &msgs[i + 1].buf[0]) < 0) 171 return -EIO; 172 ++i; 173 } else if (msgs[i].len == 3) { 174 if (msgs[i].flags & I2C_M_RD) 175 return -EIO; 176 if (go7007_i2c_xfer(go, msgs[i].addr, 0, 177 (msgs[i].buf[0] << 8) | msgs[i].buf[1], 178 0x01, &msgs[i].buf[2]) < 0) 179 return -EIO; 180 } else 181 return -EIO; 182 } 183 184 return num; 185 } 186 187 static u32 go7007_functionality(struct i2c_adapter *adapter) 188 { 189 return I2C_FUNC_SMBUS_BYTE_DATA; 190 } 191 192 static const struct i2c_algorithm go7007_algo = { 193 .smbus_xfer = go7007_smbus_xfer, 194 .master_xfer = go7007_i2c_master_xfer, 195 .functionality = go7007_functionality, 196 }; 197 198 static struct i2c_adapter go7007_adap_templ = { 199 .owner = THIS_MODULE, 200 .name = "WIS GO7007SB", 201 .algo = &go7007_algo, 202 }; 203 204 int go7007_i2c_init(struct go7007 *go) 205 { 206 memcpy(&go->i2c_adapter, &go7007_adap_templ, 207 sizeof(go7007_adap_templ)); 208 go->i2c_adapter.dev.parent = go->dev; 209 i2c_set_adapdata(&go->i2c_adapter, go); 210 if (i2c_add_adapter(&go->i2c_adapter) < 0) { 211 dev_err(go->dev, 212 "go7007-i2c: error: i2c_add_adapter failed\n"); 213 return -1; 214 } 215 return 0; 216 } 217