217 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*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 0x140024#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 0x000732#define I2C_READ_READY_MASK 0x000833 34/* There is only one I2C port on the TW2804 that feeds all four GO7007 VIPs35 * on the Adlink PCI-MPG24, so access is shared between all of them. */36static DEFINE_MUTEX(adlink_mpg24_i2c_mutex);37 38static 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 45static 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 52static 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_DEBUG62 if (read)63 dev_dbg(go->dev, "go7007-i2c: reading 0x%02x on 0x%02x\n",64 command, addr);65 else66 dev_dbg(go->dev,67 "go7007-i2c: writing 0x%02x to 0x%02x on 0x%02x\n",68 *data, command, addr);69#endif70 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 129i2c_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 136static 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 the149 * SMBus functions only support 8-bit commands and the SAA7135 uses150 * 16-bit commands. The I2C interface on the GO7007, as limited as151 * it is, does support this mode. */152 153static 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, or161 * 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 } else181 return -EIO;182 }183 184 return num;185}186 187static u32 go7007_functionality(struct i2c_adapter *adapter)188{189 return I2C_FUNC_SMBUS_BYTE_DATA;190}191 192static 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 198static struct i2c_adapter go7007_adap_templ = {199 .owner = THIS_MODULE,200 .name = "WIS GO7007SB",201 .algo = &go7007_algo,202};203 204int 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