| /* |
| * w1_ds2433.c - w1 family 23 (DS2433) driver |
| * |
| * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com> |
| * |
| * This source code is licensed under the GNU General Public License, |
| * Version 2. See the file COPYING for more details. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/device.h> |
| #include <linux/types.h> |
| #include <linux/delay.h> |
| #include <linux/slab.h> |
| #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
| #include <linux/crc16.h> |
| |
| #define CRC16_INIT 0 |
| #define CRC16_VALID 0xb001 |
| |
| #endif |
| |
| #include "../w1.h" |
| #include "../w1_int.h" |
| #include "../w1_family.h" |
| |
| #define W1_EEPROM_SIZE 512 |
| #define W1_PAGE_COUNT 16 |
| #define W1_PAGE_SIZE 32 |
| #define W1_PAGE_BITS 5 |
| #define W1_PAGE_MASK 0x1F |
| |
| #define W1_F23_TIME 300 |
| |
| #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 w1_f23_data { |
| u8 memory[W1_EEPROM_SIZE]; |
| u32 validcrc; |
| }; |
| |
| /** |
| * 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 (data->validcrc & (1 << block)) |
| return 0; |
| |
| if (w1_reset_select_slave(sl)) { |
| data->validcrc = 0; |
| 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) |
| data->validcrc |= (1 << block); |
| |
| 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 |
| |
| if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0) |
| 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; |
| } |
| |
| /** |
| * Writes to the scratchpad and reads it back for verification. |
| * Then copies the scratchpad to EEPROM. |
| * The data must be on one page. |
| * The master must be locked. |
| * |
| * @param sl The slave structure |
| * @param addr Address for the write |
| * @param len length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK)) |
| * @param data The data to write |
| * @return 0=Success -1=failure |
| */ |
| static int w1_f23_write(struct w1_slave *sl, int addr, int len, const u8 *data) |
| { |
| #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
| struct w1_f23_data *f23 = sl->family_data; |
| #endif |
| 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 5 ms to wait for the write to complete */ |
| msleep(5); |
| |
| /* Reset the bus to wake up the EEPROM (this may not be needed) */ |
| w1_reset_bus(sl->master); |
| #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
| f23->validcrc &= ~(1 << (addr >> W1_PAGE_BITS)); |
| #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; |
| |
| if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0) |
| 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 BIN_ATTR_RW(eeprom, W1_EEPROM_SIZE); |
| |
| static struct bin_attribute *w1_f23_bin_attributes[] = { |
| &bin_attr_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 int w1_f23_add_slave(struct w1_slave *sl) |
| { |
| #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
| struct w1_f23_data *data; |
| |
| data = kzalloc(sizeof(struct w1_f23_data), GFP_KERNEL); |
| if (!data) |
| return -ENOMEM; |
| sl->family_data = data; |
| |
| #endif /* CONFIG_W1_SLAVE_DS2433_CRC */ |
| return 0; |
| } |
| |
| static void w1_f23_remove_slave(struct w1_slave *sl) |
| { |
| #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
| kfree(sl->family_data); |
| sl->family_data = NULL; |
| #endif /* CONFIG_W1_SLAVE_DS2433_CRC */ |
| } |
| |
| static struct w1_family_ops w1_f23_fops = { |
| .add_slave = w1_f23_add_slave, |
| .remove_slave = w1_f23_remove_slave, |
| .groups = w1_f23_groups, |
| }; |
| |
| static struct w1_family w1_family_23 = { |
| .fid = W1_EEPROM_DS2433, |
| .fops = &w1_f23_fops, |
| }; |
| module_w1_family(w1_family_23); |
| |
| MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>"); |
| MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("w1-family-" __stringify(W1_EEPROM_DS2433)); |