/**************************************************************************** * drivers/eeprom/i2c_xx24xx.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /* This is a driver for I2C EEPROMs that use the same commands as the * xx24xx. * * The following devices should be supported: * * Manufacturer Device Bytes PgSize AddrLen DevAddr * Microchip * 24xx00 16 1 1 1010000 Special case * 24xx01 128 8 1 1010000 * 24xx02 256 8 1 1010000 * 24xx04 512 16 1 101000P * 24xx08 1024 16 1 10100PP * 24xx16 2048 16 1 1010PPP * 24xx32 4096 32 2 1010AAA * 24xx64 8192 32 2 1010AAA * 24xx128 16384 64 2 1010AAA * 24xx256 32768 64 2 1010AAA * 24xx512 65536 128 2 1010AAA * 24xx1025 131072 128 2 1010PAA Special case: address * bit is shifted. * 24xx1026 131072 128 2 1010AAP * * Atmel * AT24C01 128 8 1 1010AAA * AT24C02 256 8 1 1010AAA * AT24C04 512 16 1 1010AAP P bits = word address * AT24C08 1024 16 1 1010APP * AT24C16 2048 16 1 1010PPP * AT24C32 4096 32 2 1010AAA * AT24C64 8192 32 2 1010AAA * AT24C128 16384 64 2 10100AA * AT24C256 32768 64 2 10100AA * AT24C512 65536 128 2 10100AA * AT24C1024 131072 256 2 10100AP * * ST Microelectronics * M24C01 128 16 1 1010AAA * M24C02 256 16 1 1010AAA * M24C04 512 16 1 1010AAP * M24C08 1024 16 1 1010APP * M24C16 2048 16 1 1010PPP * M24C32 4096 32 2 1010AAA ID pages supported * as a separate device * M24C64 8192 32 2 1010AAA * M24128 16384 64 2 1010AAA * M24256 32768 64 2 1010AAA * M24512 65536 128 2 1010AAA * M24M01 131072 256 2 1010AAP * M24M02 262144 256 2 1010APP */ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #ifndef CONFIG_EE24XX_FREQUENCY # define CONFIG_EE24XX_FREQUENCY 100000 #endif #define UUID_SIZE 16 /**************************************************************************** * Types ****************************************************************************/ /* Device geometry description, compact form (2 bytes per entry) */ struct ee24xx_geom_s { uint8_t bytes : 4; /* Power of two of 128 bytes (0:128 ... 11:262144) */ uint8_t pagesize : 4; /* Power of two of 8 bytes (0:8 1:16 2:32 3:64 etc) */ uint8_t addrlen : 4; /* Nr of bytes in command address field */ uint8_t abits : 3; /* Nr of Address MSBits in the i2c device address LSBs */ uint8_t special : 1; /* Special device: uchip 24xx00 (total 16 bytes) * or 24xx1025 (shifted P bits) */ }; /* Private data attached to the inode */ struct ee24xx_dev_s { /* Bus management */ struct i2c_master_s *i2c; /* I2C device where the EEPROM is attached */ uint32_t freq; /* I2C bus speed */ uint8_t addr; /* 7-bit unshifted I2C device address */ /* Driver management */ sem_t sem; /* file write access serialization */ uint8_t refs; /* Nr of times the device has been opened */ bool readonly; /* Flags */ /* Expanded from geometry */ uint32_t size; /* total bytes in device */ uint16_t pgsize; /* write block size, in bytes */ uint16_t addrlen; /* number of bytes in data addresses */ uint16_t haddrbits; /* Number of bits in high address part */ uint16_t haddrshift; /* bit-shift of high address part */ }; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ static int ee24xx_open(FAR struct file *filep); static int ee24xx_close(FAR struct file *filep); static off_t ee24xx_seek(FAR struct file *filep, off_t offset, int whence); static ssize_t ee24xx_read(FAR struct file *filep, FAR char *buffer, size_t buflen); static ssize_t ee24xx_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); static int ee24xx_ioctl(FAR struct file *filep, int cmd, unsigned long arg); #ifdef CONFIG_AT24CS_UUID static ssize_t at24cs_read_uuid(FAR struct file *filep, FAR char *buffer, size_t buflen); #endif /**************************************************************************** * Private Data ****************************************************************************/ /* Supported device geometries. * One geometry can fit more than one device. * The user will use an enum'ed index from include/eeprom/i2c_xx24xx.h */ static const struct ee24xx_geom_s g_ee24xx_devices[] = { /* Microchip devices */ /* by pg al ab sp device bytes page alen */ { 0, 1, 1, 0, 1 }, /* 24xx00 16 1 1 Ridiculously small device */ { 0, 0, 1, 0, 0 }, /* 24xx01 128 8 1 */ { 1, 0, 1, 0, 0 }, /* 24xx02 256 8 1 */ { 2, 1, 1, 1, 0 }, /* 24xx04 512 16 1 */ { 3, 1, 1, 2, 0 }, /* 24xx08 1024 16 1 */ { 4, 1, 1, 3, 0 }, /* 24xx16 2048 16 1 */ { 5, 2, 2, 0, 0 }, /* 24xx32 4096 32 2 */ { 6, 2, 2, 0, 0 }, /* 24xx64 8192 32 2 */ { 7, 3, 2, 0, 0 }, /* 24xx128 16384 64 2 */ { 8, 3, 2, 0, 0 }, /* 24xx256 32768 64 2 */ { 9, 4, 2, 0, 0 }, /* 24xx512 65536 128 2 */ { 10, 4, 2, 1, 1 }, /* 24xx1025 131072 128 2 Shifted address, todo */ { 10, 4, 2, 1, 0 }, /* 24xx1026 131072 128 2 */ { 11, 5, 2, 2, 0 }, /* AT24CM02 262144 256 2 */ /* STM devices */ { 0, 1, 1, 0, 0 }, /* M24C01 128 16 1 */ { 1, 1, 1, 0, 0 }, /* M24C02 256 16 1 */ { 11, 5, 2, 2, 0 }, /* M24M02 262144 256 2 */ }; /* Driver operations */ static const struct file_operations ee24xx_fops = { ee24xx_open, /* open */ ee24xx_close, /* close */ ee24xx_read, /* read */ ee24xx_write, /* write */ ee24xx_seek, /* seek */ ee24xx_ioctl, /* ioctl */ NULL /* poll */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS , NULL /* unlink */ #endif }; #ifdef CONFIG_AT24CS_UUID static const struct file_operations at24cs_uuid_fops = { ee24xx_open, /* piggyback on the ee24xx_open */ ee24xx_close, /* piggyback on the ee24xx_close */ at24cs_read_uuid, /* read */ NULL, /* write */ NULL, /* seek */ NULL, /* ioctl */ NULL /* poll */ #ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS , NULL /* unlink */ #endif }; #endif /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: ee24xx_waitwritecomplete * * Use ACK polling to detect the completion of the write operation. * Returns TRUE if write is complete (device replies to ACK). * ****************************************************************************/ static int ee24xx_waitwritecomplete(FAR struct ee24xx_dev_s *eedev, uint32_t memaddr) { struct i2c_msg_s msgs[1]; int ret; int retries = 500; uint8_t adr; uint32_t addr_hi = (memaddr >> (eedev->addrlen << 3)); msgs[0].frequency = eedev->freq; msgs[0].addr = eedev->addr | (addr_hi & ((1 << eedev->haddrbits) - 1)); msgs[0].flags = I2C_M_READ; msgs[0].buffer = &adr; msgs[0].length = 1; do { ret = I2C_TRANSFER(eedev->i2c, msgs, 1); retries--; } while (ret != 0 && retries > 0); return ret; } /**************************************************************************** * Name: ee24xx_writepage * * Description: Write data to the EEPROM, NOT crossing page boundaries. * To avoid allocating a buffer to prepend the address, we are using 2 I2C * messages while avoiding beginning the second one with a restart condition. * ****************************************************************************/ static int ee24xx_writepage(FAR struct ee24xx_dev_s *eedev, uint32_t memaddr, FAR const char *buffer, size_t len) { struct i2c_msg_s msgs[2]; uint8_t maddr[2]; uint32_t addr_hi = (memaddr >> (eedev->addrlen << 3)); /* Write data address */ maddr[0] = memaddr >> 8; maddr[1] = memaddr & 0xff; msgs[0].frequency = eedev->freq; msgs[0].addr = eedev->addr | (addr_hi & ((1 << eedev->haddrbits) - 1)); msgs[0].flags = 0; msgs[0].buffer = eedev->addrlen == 2 ? &maddr[0] : &maddr[1]; msgs[0].length = eedev->addrlen; /* Write data without a restart nor a control byte */ msgs[1].frequency = msgs[0].frequency; msgs[1].addr = msgs[0].addr; msgs[1].flags = I2C_M_NOSTART; msgs[1].buffer = (uint8_t *)buffer; msgs[1].length = len; return I2C_TRANSFER(eedev->i2c, msgs, 2); } /**************************************************************************** * Name: ee24xx_semtake * * Acquire a resource to access the device. * The purpose of the semaphore is to block tasks that try to access the * EEPROM while another task is actively using it. * ****************************************************************************/ static int ee24xx_semtake(FAR struct ee24xx_dev_s *eedev) { return nxsem_wait_uninterruptible(&eedev->sem); } /**************************************************************************** * Name: ee24xx_semgive * * Release a resource to access the device. * ****************************************************************************/ static inline void ee24xx_semgive(FAR struct ee24xx_dev_s *eedev) { nxsem_post(&eedev->sem); } /**************************************************************************** * Driver Functions ****************************************************************************/ /**************************************************************************** * Name: ee24xx_open * * Description: Open the block device * ****************************************************************************/ static int ee24xx_open(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct ee24xx_dev_s *eedev; int ret = OK; DEBUGASSERT(inode && inode->i_private); eedev = (FAR struct ee24xx_dev_s *)inode->i_private; ret = ee24xx_semtake(eedev); if (ret < 0) { return ret; } /* Increment the reference count */ if ((eedev->refs + 1) == 0) { ret = -EMFILE; } else { eedev->refs += 1; } ee24xx_semgive(eedev); return ret; } /**************************************************************************** * Name: ee24xx_close * * Description: Close the block device * ****************************************************************************/ static int ee24xx_close(FAR struct file *filep) { FAR struct inode *inode = filep->f_inode; FAR struct ee24xx_dev_s *eedev; int ret = OK; DEBUGASSERT(inode && inode->i_private); eedev = (FAR struct ee24xx_dev_s *)inode->i_private; ret = ee24xx_semtake(eedev); if (ret < 0) { return ret; } /* Decrement the reference count. I want the entire close operation * to be atomic wrt other driver operations. */ if (eedev->refs == 0) { ret = -EIO; } else { eedev->refs -= 1; } ee24xx_semgive(eedev); return ret; } /**************************************************************************** * Name: ee24xx_seek * * Remark: Copied from bchlib * ****************************************************************************/ static off_t ee24xx_seek(FAR struct file *filep, off_t offset, int whence) { FAR struct ee24xx_dev_s *eedev; off_t newpos; int ret; FAR struct inode *inode = filep->f_inode; DEBUGASSERT(inode && inode->i_private); eedev = (FAR struct ee24xx_dev_s *)inode->i_private; ret = ee24xx_semtake(eedev); if (ret < 0) { return ret; } /* Determine the new, requested file position */ switch (whence) { case SEEK_CUR: newpos = filep->f_pos + offset; break; case SEEK_SET: newpos = offset; break; case SEEK_END: newpos = eedev->size + offset; break; default: /* Return EINVAL if the whence argument is invalid */ ee24xx_semgive(eedev); return -EINVAL; } /* Opengroup.org: * * "The lseek() function shall allow the file offset to be set beyond the * end of the existing data in the file. If data is later written at * this point, subsequent reads of data in the gap shall return bytes * with the value 0 until data is actually written into the gap." * * We can conform to the first part, but not the second. But return EINVAL * if * * "...the resulting file offset would be negative for a regular file, * block special file, or directory." */ if (newpos >= 0) { filep->f_pos = newpos; ret = newpos; finfo("SEEK newpos %d\n", newpos); } else { ret = -EINVAL; } ee24xx_semgive(eedev); return ret; } /**************************************************************************** * Name: ee24xx_read ****************************************************************************/ static ssize_t ee24xx_read(FAR struct file *filep, FAR char *buffer, size_t len) { FAR struct ee24xx_dev_s *eedev; FAR struct inode *inode = filep->f_inode; struct i2c_msg_s msgs[2]; uint8_t addr[2]; uint32_t addr_hi; int ret; DEBUGASSERT(inode && inode->i_private); eedev = (FAR struct ee24xx_dev_s *)inode->i_private; ret = ee24xx_semtake(eedev); if (ret < 0) { return ret; } /* trim len if read would go beyond end of device */ if ((filep->f_pos + len) > eedev->size) { len = eedev->size - filep->f_pos; } if (len == 0) { /* We are at end of file */ ret = 0; goto done; } /* Write data address */ finfo("READ %d bytes at pos %d\n", len, filep->f_pos); addr_hi = (filep->f_pos >> (eedev->addrlen << 3)); addr[0] = (filep->f_pos) >> 8; addr[1] = (filep->f_pos) & 0xff; msgs[0].frequency = eedev->freq; msgs[0].addr = eedev->addr | (addr_hi & ((1 << eedev->haddrbits) - 1)); msgs[0].flags = 0; msgs[0].buffer = eedev->addrlen == 2 ? &addr[0] : &addr[1]; msgs[0].length = eedev->addrlen; /* Read data */ msgs[1].frequency = msgs[0].frequency; msgs[1].addr = msgs[0].addr; msgs[1].flags = I2C_M_READ; msgs[1].buffer = (uint8_t *)buffer; msgs[1].length = len; ret = I2C_TRANSFER(eedev->i2c, msgs, 2); if (ret < 0) { goto done; } ret = len; /* Update the file position */ filep->f_pos += len; done: ee24xx_semgive(eedev); return ret; } /**************************************************************************** * Name: at24cs_read_uuid ****************************************************************************/ #ifdef CONFIG_AT24CS_UUID static ssize_t at24cs_read_uuid(FAR struct file *filep, FAR char *buffer, size_t len) { FAR struct ee24xx_dev_s *eedev; FAR struct inode *inode = filep->f_inode; struct i2c_msg_s msgs[2]; uint8_t regindx; int ret; DEBUGASSERT(inode && inode->i_private); eedev = (FAR struct ee24xx_dev_s *)inode->i_private; ret = ee24xx_semtake(eedev); if (ret < 0) { return ret; } /* trim len if read would go beyond end of device */ if ((filep->f_pos + len) > UUID_SIZE) { len = UUID_SIZE - filep->f_pos; } if (len == 0) { /* We are at end of file */ ret = 0; goto done; } /* Write data address */ finfo("READ %d bytes at pos %d\n", len, filep->f_pos); regindx = 0x80; /* reg index of UUID[0] */ msgs[0].frequency = eedev->freq; msgs[0].addr = eedev->addr + 8; /* slave addr of UUID */ msgs[0].flags = 0; msgs[0].buffer = ®indx; msgs[0].length = 1; /* Read data */ msgs[1].frequency = msgs[0].frequency; msgs[1].addr = msgs[0].addr; msgs[1].flags = I2C_M_READ; msgs[1].buffer = (uint8_t *)buffer; msgs[1].length = len; ret = I2C_TRANSFER(eedev->i2c, msgs, 2); if (ret < 0) { goto done; } ret = len; /* Update the file position */ filep->f_pos += len; done: ee24xx_semgive(eedev); return ret; } #endif /**************************************************************************** * Name: ee24xx_write ****************************************************************************/ static ssize_t ee24xx_write(FAR struct file *filep, FAR const char *buffer, size_t len) { FAR struct ee24xx_dev_s *eedev; size_t cnt; int pageoff; FAR struct inode *inode = filep->f_inode; int ret = -EACCES; int savelen; DEBUGASSERT(inode && inode->i_private); eedev = (FAR struct ee24xx_dev_s *)inode->i_private; if (eedev->readonly) { return ret; } /* Forbid writes past the end of the device */ if (filep->f_pos >= eedev->size) { return -EFBIG; } finfo("Entering with len=%d\n", len); /* Clamp len to avoid crossing the end of the memory */ if ((len + filep->f_pos) > eedev->size) { len = eedev->size - filep->f_pos; finfo("Len clamped to %d\n", len); } savelen = len; /* save number of bytes written */ ret = ee24xx_semtake(eedev); if (ret < 0) { return ret; } /* Writes can't happen in a row like the read does. * The EEPROM is made of pages, and write sequences * cannot cross page boundaries. So every time the last * byte of a page is programmed, a separate I2C transaction * required to continue writing. */ /* First, write some page-unaligned data */ pageoff = filep->f_pos & (eedev->pgsize - 1); cnt = eedev->pgsize - pageoff; if (cnt > len) { cnt = len; } if (pageoff > 0) { finfo("First %d unaligned bytes at %d (pageoff %d)\n", cnt, filep->f_pos, pageoff); ret = ee24xx_writepage(eedev, filep->f_pos, buffer, cnt); if (ret < 0) { ferr("write failed, ret = %d\n", ret); goto done; } ret = ee24xx_waitwritecomplete(eedev, filep->f_pos); if (ret < 0) { ferr("writecomplete failed, ret = %d\n", ret); goto done; } len -= cnt; buffer += cnt; filep->f_pos += cnt; } /* Then, write remaining bytes at page-aligned addresses */ while (len > 0) { cnt = len; if (cnt > eedev->pgsize) { cnt = eedev->pgsize; } finfo("Aligned page write for %d bytes at %d\n", cnt, filep->f_pos); ret = ee24xx_writepage(eedev, filep->f_pos, buffer, cnt); if (ret < 0) { ferr("write failed, ret = %d\n", ret); goto done; } ret = ee24xx_waitwritecomplete(eedev, filep->f_pos); if (ret < 0) { ferr("writecomplete failed, ret = %d\n", ret); goto done; } len -= cnt; buffer += cnt; filep->f_pos += cnt; } ret = savelen; done: ee24xx_semgive(eedev); return ret; } /**************************************************************************** * Name: ee24xx_ioctl * * Description: TODO: Erase a sector/page/device or read device ID / MAC. * This is completely optional. * ****************************************************************************/ static int ee24xx_ioctl(FAR struct file *filep, int cmd, unsigned long arg) { FAR struct ee24xx_dev_s *eedev; FAR struct inode *inode = filep->f_inode; int ret = 0; DEBUGASSERT(inode && inode->i_private); eedev = (FAR struct ee24xx_dev_s *)inode->i_private; UNUSED(eedev); switch (cmd) { default: ret = -ENOTTY; } return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: ee24xx_initialize * * Description: Bind a EEPROM driver to an I2C bus. The user MUST provide * a description of the device geometry, since it is not possible to read * this information from the device (contrary to the SPI flash devices). * ****************************************************************************/ int ee24xx_initialize(FAR struct i2c_master_s *bus, uint8_t devaddr, FAR char *devname, int devtype, int readonly) { FAR struct ee24xx_dev_s *eedev; #ifdef CONFIG_AT24CS_UUID FAR char *uuidname; int ret; #endif /* Check device type early */ if ((devtype < 0) || (devtype >= sizeof(g_ee24xx_devices) / sizeof(g_ee24xx_devices[0]))) { return -EINVAL; } eedev = kmm_zalloc(sizeof(struct ee24xx_dev_s)); if (!eedev) { return -ENOMEM; } nxsem_init(&eedev->sem, 0, 1); eedev->freq = CONFIG_EE24XX_FREQUENCY; eedev->i2c = bus; eedev->addr = devaddr; eedev->readonly = !!readonly; /* Expand device geometry from compacted info */ eedev->size = 128 << g_ee24xx_devices[devtype].bytes; eedev->pgsize = 8 << g_ee24xx_devices[devtype].pagesize; eedev->addrlen = g_ee24xx_devices[devtype].addrlen; eedev->haddrbits = g_ee24xx_devices[devtype].abits; eedev->haddrshift = 0; /* Apply special properties */ if (g_ee24xx_devices[devtype].special) { if (devtype == EEPROM_24XX00) { /* Ultra small 16-byte EEPROM */ eedev->size = 16; /* The device only has BYTE write, * which is emulated with 1-byte pages */ eedev->pgsize = 1; } else if (devtype == EEPROM_24XX1025) { /* Microchip alien part where the address MSB is << 2 bits */ ferr("Device 24xx1025 is not supported for the moment, TODO.\n"); eedev->haddrshift = 2; kmm_free(eedev); return -ENODEV; } } finfo("EEPROM device %s, %d bytes, %d per page, addrlen %d, %s\n", devname, eedev->size, eedev->pgsize, eedev->addrlen, eedev->readonly ? "readonly" : ""); #ifdef CONFIG_AT24CS_UUID uuidname = kmm_zalloc(strlen(devname) + 8); if (!uuidname) { return -ENOMEM; } /* register the UUID I2C slave with the same name as the parent * EEPROM chip, but with the ".uuid" suffix */ strcpy(uuidname, devname); strcat(uuidname, ".uuid"); ret = register_driver(uuidname, &at24cs_uuid_fops, 0444, eedev); kmm_free(uuidname); if (OK != ret) { ferr("register uuid failed, ret = %d\n", ret); return ret; } #endif return register_driver(devname, &ee24xx_fops, 0666, eedev); }