Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (C) 2005-2006 Micronas USA Inc. |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 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_lock); |
| 37 | |
| 38 | static 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 | |
| 118 | i2c_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 | |
| 128 | static 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 | |
| 145 | static 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 (msgs[i].len != 3) |
| 169 | return -EIO; |
| 170 | if (go7007_i2c_xfer(go, msgs[i].addr, 0, |
| 171 | (msgs[i].buf[0] << 8) | msgs[i].buf[1], |
| 172 | 0x01, &msgs[i].buf[2]) < 0) |
| 173 | return -EIO; |
| 174 | } else |
| 175 | return -EIO; |
| 176 | } |
| 177 | |
| 178 | return num; |
| 179 | } |
| 180 | |
| 181 | static u32 go7007_functionality(struct i2c_adapter *adapter) |
| 182 | { |
| 183 | return I2C_FUNC_SMBUS_BYTE_DATA; |
| 184 | } |
| 185 | |
| 186 | static const struct i2c_algorithm go7007_algo = { |
| 187 | .smbus_xfer = go7007_smbus_xfer, |
| 188 | .master_xfer = go7007_i2c_master_xfer, |
| 189 | .functionality = go7007_functionality, |
| 190 | }; |
| 191 | |
| 192 | static struct i2c_adapter go7007_adap_templ = { |
| 193 | .owner = THIS_MODULE, |
| 194 | .name = "WIS GO7007SB", |
| 195 | .algo = &go7007_algo, |
| 196 | }; |
| 197 | |
| 198 | int go7007_i2c_init(struct go7007 *go) |
| 199 | { |
| 200 | memcpy(&go->i2c_adapter, &go7007_adap_templ, |
| 201 | sizeof(go7007_adap_templ)); |
| 202 | go->i2c_adapter.dev.parent = go->dev; |
| 203 | i2c_set_adapdata(&go->i2c_adapter, go); |
| 204 | if (i2c_add_adapter(&go->i2c_adapter) < 0) { |
| 205 | dev_err(go->dev, |
| 206 | "go7007-i2c: error: i2c_add_adapter failed\n"); |
| 207 | return -1; |
| 208 | } |
| 209 | return 0; |
| 210 | } |