// SPDX-License-Identifier: GPL-2.0-only /* * w1_ds2433.c - w1 family 23 (DS2433) & 43 (DS28EC20) eeprom driver * * Copyright (c) 2005 Ben Gardner * Copyright (c) 2023 Marc Ferland */ #include #include #include #include #include #include #include #ifdef CONFIG_W1_SLAVE_DS2433_CRC #include #define CRC16_INIT 0 #define CRC16_VALID 0xb001 #endif #include #define W1_EEPROM_DS2433 0x23 #define W1_EEPROM_DS28EC20 0x43 #define W1_EEPROM_DS2433_SIZE 512 #define W1_EEPROM_DS28EC20_SIZE 2560 #define W1_PAGE_SIZE 32 #define W1_PAGE_BITS 5 #define W1_PAGE_MASK 0x1F #define W1_VALIDCRC_MAX 96 #define W1_F23_READ_EEPROM 0xF0 #define W1_F23_WRITE_SCRATCH 0x0F #define W1_F23_READ_SCRATCH 0xAA #define W1_F23_COPY_SCRATCH 0x55 struct ds2433_config { size_t eeprom_size; /* eeprom size in bytes */ unsigned int page_count; /* number of 256 bits pages */ unsigned int tprog; /* time in ms for page programming */ }; static const struct ds2433_config config_f23 = { .eeprom_size = W1_EEPROM_DS2433_SIZE, .page_count = 16, .tprog = 5, }; static const struct ds2433_config config_f43 = { .eeprom_size = W1_EEPROM_DS28EC20_SIZE, .page_count = 80, .tprog = 10, }; struct w1_f23_data { #ifdef CONFIG_W1_SLAVE_DS2433_CRC u8 *memory; DECLARE_BITMAP(validcrc, W1_VALIDCRC_MAX); #endif const struct ds2433_config *cfg; }; /* * Check the file size bounds and adjusts count as needed. * This would not be needed if the file size didn't reset to 0 after a write. */ static inline size_t w1_f23_fix_count(loff_t off, size_t count, size_t size) { if (off > size) return 0; if ((off + count) > size) return (size - off); return count; } #ifdef CONFIG_W1_SLAVE_DS2433_CRC static int w1_f23_refresh_block(struct w1_slave *sl, struct w1_f23_data *data, int block) { u8 wrbuf[3]; int off = block * W1_PAGE_SIZE; if (test_bit(block, data->validcrc)) return 0; if (w1_reset_select_slave(sl)) { bitmap_zero(data->validcrc, data->cfg->page_count); return -EIO; } wrbuf[0] = W1_F23_READ_EEPROM; wrbuf[1] = off & 0xff; wrbuf[2] = off >> 8; w1_write_block(sl->master, wrbuf, 3); w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE); /* cache the block if the CRC is valid */ if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID) set_bit(block, data->validcrc); return 0; } #endif /* CONFIG_W1_SLAVE_DS2433_CRC */ static ssize_t eeprom_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { struct w1_slave *sl = kobj_to_w1_slave(kobj); #ifdef CONFIG_W1_SLAVE_DS2433_CRC struct w1_f23_data *data = sl->family_data; int i, min_page, max_page; #else u8 wrbuf[3]; #endif count = w1_f23_fix_count(off, count, bin_attr->size); if (!count) return 0; mutex_lock(&sl->master->bus_mutex); #ifdef CONFIG_W1_SLAVE_DS2433_CRC min_page = (off >> W1_PAGE_BITS); max_page = (off + count - 1) >> W1_PAGE_BITS; for (i = min_page; i <= max_page; i++) { if (w1_f23_refresh_block(sl, data, i)) { count = -EIO; goto out_up; } } memcpy(buf, &data->memory[off], count); #else /* CONFIG_W1_SLAVE_DS2433_CRC */ /* read directly from the EEPROM */ if (w1_reset_select_slave(sl)) { count = -EIO; goto out_up; } wrbuf[0] = W1_F23_READ_EEPROM; wrbuf[1] = off & 0xff; wrbuf[2] = off >> 8; w1_write_block(sl->master, wrbuf, 3); w1_read_block(sl->master, buf, count); #endif /* CONFIG_W1_SLAVE_DS2433_CRC */ out_up: mutex_unlock(&sl->master->bus_mutex); return count; } /** * w1_f23_write() - Writes to the scratchpad and reads it back for verification. * @sl: The slave structure * @addr: Address for the write * @len: length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK)) * @data: The data to write * * Then copies the scratchpad to EEPROM. * The data must be on one page. * The master must be locked. * * Return: 0=Success, -1=failure */ static int w1_f23_write(struct w1_slave *sl, int addr, int len, const u8 *data) { struct w1_f23_data *f23 = sl->family_data; u8 wrbuf[4]; u8 rdbuf[W1_PAGE_SIZE + 3]; u8 es = (addr + len - 1) & 0x1f; /* Write the data to the scratchpad */ if (w1_reset_select_slave(sl)) return -1; wrbuf[0] = W1_F23_WRITE_SCRATCH; wrbuf[1] = addr & 0xff; wrbuf[2] = addr >> 8; w1_write_block(sl->master, wrbuf, 3); w1_write_block(sl->master, data, len); /* Read the scratchpad and verify */ if (w1_reset_select_slave(sl)) return -1; w1_write_8(sl->master, W1_F23_READ_SCRATCH); w1_read_block(sl->master, rdbuf, len + 3); /* Compare what was read against the data written */ if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) || (rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0)) return -1; /* Copy the scratchpad to EEPROM */ if (w1_reset_select_slave(sl)) return -1; wrbuf[0] = W1_F23_COPY_SCRATCH; wrbuf[3] = es; w1_write_block(sl->master, wrbuf, 4); /* Sleep for tprog ms to wait for the write to complete */ msleep(f23->cfg->tprog); /* Reset the bus to wake up the EEPROM (this may not be needed) */ w1_reset_bus(sl->master); #ifdef CONFIG_W1_SLAVE_DS2433_CRC clear_bit(addr >> W1_PAGE_BITS, f23->validcrc); #endif return 0; } static ssize_t eeprom_write(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { struct w1_slave *sl = kobj_to_w1_slave(kobj); int addr, len, idx; count = w1_f23_fix_count(off, count, bin_attr->size); if (!count) return 0; #ifdef CONFIG_W1_SLAVE_DS2433_CRC /* can only write full blocks in cached mode */ if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) { dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n", (int)off, count); return -EINVAL; } /* make sure the block CRCs are valid */ for (idx = 0; idx < count; idx += W1_PAGE_SIZE) { if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE) != CRC16_VALID) { dev_err(&sl->dev, "bad CRC at offset %d\n", (int)off); return -EINVAL; } } #endif /* CONFIG_W1_SLAVE_DS2433_CRC */ mutex_lock(&sl->master->bus_mutex); /* Can only write data to one page at a time */ idx = 0; while (idx < count) { addr = off + idx; len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK); if (len > (count - idx)) len = count - idx; if (w1_f23_write(sl, addr, len, &buf[idx]) < 0) { count = -EIO; goto out_up; } idx += len; } out_up: mutex_unlock(&sl->master->bus_mutex); return count; } static struct bin_attribute bin_attr_f23_eeprom = { .attr = { .name = "eeprom", .mode = 0644 }, .read = eeprom_read, .write = eeprom_write, .size = W1_EEPROM_DS2433_SIZE, }; static struct bin_attribute bin_attr_f43_eeprom = { .attr = { .name = "eeprom", .mode = 0644 }, .read = eeprom_read, .write = eeprom_write, .size = W1_EEPROM_DS28EC20_SIZE, }; static struct bin_attribute *w1_f23_bin_attributes[] = { &bin_attr_f23_eeprom, NULL, }; static const struct attribute_group w1_f23_group = { .bin_attrs = w1_f23_bin_attributes, }; static const struct attribute_group *w1_f23_groups[] = { &w1_f23_group, NULL, }; static struct bin_attribute *w1_f43_bin_attributes[] = { &bin_attr_f43_eeprom, NULL, }; static const struct attribute_group w1_f43_group = { .bin_attrs = w1_f43_bin_attributes, }; static const struct attribute_group *w1_f43_groups[] = { &w1_f43_group, NULL, }; static int w1_f23_add_slave(struct w1_slave *sl) { struct w1_f23_data *data; data = kzalloc(sizeof(struct w1_f23_data), GFP_KERNEL); if (!data) return -ENOMEM; switch (sl->family->fid) { case W1_EEPROM_DS2433: data->cfg = &config_f23; break; case W1_EEPROM_DS28EC20: data->cfg = &config_f43; break; } #ifdef CONFIG_W1_SLAVE_DS2433_CRC if (data->cfg->page_count > W1_VALIDCRC_MAX) { dev_err(&sl->dev, "page count too big for crc bitmap\n"); kfree(data); return -EINVAL; } data->memory = kzalloc(data->cfg->eeprom_size, GFP_KERNEL); if (!data->memory) { kfree(data); return -ENOMEM; } bitmap_zero(data->validcrc, data->cfg->page_count); #endif /* CONFIG_W1_SLAVE_DS2433_CRC */ sl->family_data = data; return 0; } static void w1_f23_remove_slave(struct w1_slave *sl) { struct w1_f23_data *data = sl->family_data; sl->family_data = NULL; #ifdef CONFIG_W1_SLAVE_DS2433_CRC kfree(data->memory); #endif /* CONFIG_W1_SLAVE_DS2433_CRC */ kfree(data); } static const struct w1_family_ops w1_f23_fops = { .add_slave = w1_f23_add_slave, .remove_slave = w1_f23_remove_slave, .groups = w1_f23_groups, }; static const struct w1_family_ops w1_f43_fops = { .add_slave = w1_f23_add_slave, .remove_slave = w1_f23_remove_slave, .groups = w1_f43_groups, }; static struct w1_family w1_family_23 = { .fid = W1_EEPROM_DS2433, .fops = &w1_f23_fops, }; static struct w1_family w1_family_43 = { .fid = W1_EEPROM_DS28EC20, .fops = &w1_f43_fops, }; static int __init w1_ds2433_init(void) { int err; err = w1_register_family(&w1_family_23); if (err) return err; err = w1_register_family(&w1_family_43); if (err) goto err_43; return 0; err_43: w1_unregister_family(&w1_family_23); return err; } static void __exit w1_ds2433_exit(void) { w1_unregister_family(&w1_family_23); w1_unregister_family(&w1_family_43); } module_init(w1_ds2433_init); module_exit(w1_ds2433_exit); MODULE_AUTHOR("Ben Gardner "); MODULE_AUTHOR("Marc Ferland "); MODULE_DESCRIPTION("w1 family 23/43 driver for DS2433 (4kb) and DS28EC20 (20kb)"); MODULE_LICENSE("GPL"); MODULE_ALIAS("w1-family-" __stringify(W1_EEPROM_DS2433)); MODULE_ALIAS("w1-family-" __stringify(W1_EEPROM_DS28EC20));