Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Markus Franke | 1752 | 93.89% | 1 | 20.00% |
Greg Kroah-Hartman | 83 | 4.45% | 1 | 20.00% |
Andrew F. Davis | 31 | 1.66% | 3 | 60.00% |
Total | 1866 | 5 |
/* * w1_ds28e04.c - w1 family 1C (DS28E04) driver * * Copyright (c) 2012 Markus Franke <franke.m@sebakmt.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> #include <linux/crc16.h> #include <linux/uaccess.h> #define CRC16_INIT 0 #define CRC16_VALID 0xb001 #include <linux/w1.h> #define W1_FAMILY_DS28E04 0x1C /* Allow the strong pullup to be disabled, but default to enabled. * If it was disabled a parasite powered device might not get the required * current to copy the data from the scratchpad to EEPROM. If it is enabled * parasite powered devices have a better chance of getting the current * required. */ static int w1_strong_pullup = 1; module_param_named(strong_pullup, w1_strong_pullup, int, 0); /* enable/disable CRC checking on DS28E04-100 memory accesses */ static char w1_enable_crccheck = 1; #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_F1C_READ_EEPROM 0xF0 #define W1_F1C_WRITE_SCRATCH 0x0F #define W1_F1C_READ_SCRATCH 0xAA #define W1_F1C_COPY_SCRATCH 0x55 #define W1_F1C_ACCESS_WRITE 0x5A #define W1_1C_REG_LOGIC_STATE 0x220 struct w1_f1C_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_f1C_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; } static int w1_f1C_refresh_block(struct w1_slave *sl, struct w1_f1C_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_F1C_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; } static int w1_f1C_read(struct w1_slave *sl, int addr, int len, char *data) { u8 wrbuf[3]; /* read directly from the EEPROM */ if (w1_reset_select_slave(sl)) return -EIO; wrbuf[0] = W1_F1C_READ_EEPROM; wrbuf[1] = addr & 0xff; wrbuf[2] = addr >> 8; w1_write_block(sl->master, wrbuf, sizeof(wrbuf)); return w1_read_block(sl->master, data, len); } 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); struct w1_f1C_data *data = sl->family_data; int i, min_page, max_page; count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE); if (count == 0) return 0; mutex_lock(&sl->master->mutex); if (w1_enable_crccheck) { min_page = (off >> W1_PAGE_BITS); max_page = (off + count - 1) >> W1_PAGE_BITS; for (i = min_page; i <= max_page; i++) { if (w1_f1C_refresh_block(sl, data, i)) { count = -EIO; goto out_up; } } memcpy(buf, &data->memory[off], count); } else { count = w1_f1C_read(sl, off, count, buf); } out_up: mutex_unlock(&sl->master->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_f1C_write(struct w1_slave *sl, int addr, int len, const u8 *data) { u8 wrbuf[4]; u8 rdbuf[W1_PAGE_SIZE + 3]; u8 es = (addr + len - 1) & 0x1f; unsigned int tm = 10; int i; struct w1_f1C_data *f1C = sl->family_data; /* Write the data to the scratchpad */ if (w1_reset_select_slave(sl)) return -1; wrbuf[0] = W1_F1C_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_F1C_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_F1C_COPY_SCRATCH; wrbuf[3] = es; for (i = 0; i < sizeof(wrbuf); ++i) { /* issue 10ms strong pullup (or delay) on the last byte for writing the data from the scratchpad to EEPROM */ if (w1_strong_pullup && i == sizeof(wrbuf)-1) w1_next_pullup(sl->master, tm); w1_write_8(sl->master, wrbuf[i]); } if (!w1_strong_pullup) msleep(tm); if (w1_enable_crccheck) { /* invalidate cached data */ f1C->validcrc &= ~(1 << (addr >> W1_PAGE_BITS)); } /* Reset the bus to wake up the EEPROM (this may not be needed) */ w1_reset_bus(sl->master); 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_f1C_fix_count(off, count, W1_EEPROM_SIZE); if (count == 0) return 0; if (w1_enable_crccheck) { /* 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; } } } mutex_lock(&sl->master->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_f1C_write(sl, addr, len, &buf[idx]) < 0) { count = -EIO; goto out_up; } idx += len; } out_up: mutex_unlock(&sl->master->mutex); return count; } static BIN_ATTR_RW(eeprom, W1_EEPROM_SIZE); static ssize_t pio_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); int ret; /* check arguments */ if (off != 0 || count != 1 || buf == NULL) return -EINVAL; mutex_lock(&sl->master->mutex); ret = w1_f1C_read(sl, W1_1C_REG_LOGIC_STATE, count, buf); mutex_unlock(&sl->master->mutex); return ret; } static ssize_t pio_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); u8 wrbuf[3]; u8 ack; /* check arguments */ if (off != 0 || count != 1 || buf == NULL) return -EINVAL; mutex_lock(&sl->master->mutex); /* Write the PIO data */ if (w1_reset_select_slave(sl)) { mutex_unlock(&sl->master->mutex); return -1; } /* set bit 7..2 to value '1' */ *buf = *buf | 0xFC; wrbuf[0] = W1_F1C_ACCESS_WRITE; wrbuf[1] = *buf; wrbuf[2] = ~(*buf); w1_write_block(sl->master, wrbuf, 3); w1_read_block(sl->master, &ack, sizeof(ack)); mutex_unlock(&sl->master->mutex); /* check for acknowledgement */ if (ack != 0xAA) return -EIO; return count; } static BIN_ATTR_RW(pio, 1); static ssize_t crccheck_show(struct device *dev, struct device_attribute *attr, char *buf) { if (put_user(w1_enable_crccheck + 0x30, buf)) return -EFAULT; return sizeof(w1_enable_crccheck); } static ssize_t crccheck_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { char val; if (count != 1 || !buf) return -EINVAL; if (get_user(val, buf)) return -EFAULT; /* convert to decimal */ val = val - 0x30; if (val != 0 && val != 1) return -EINVAL; /* set the new value */ w1_enable_crccheck = val; return sizeof(w1_enable_crccheck); } static DEVICE_ATTR_RW(crccheck); static struct attribute *w1_f1C_attrs[] = { &dev_attr_crccheck.attr, NULL, }; static struct bin_attribute *w1_f1C_bin_attrs[] = { &bin_attr_eeprom, &bin_attr_pio, NULL, }; static const struct attribute_group w1_f1C_group = { .attrs = w1_f1C_attrs, .bin_attrs = w1_f1C_bin_attrs, }; static const struct attribute_group *w1_f1C_groups[] = { &w1_f1C_group, NULL, }; static int w1_f1C_add_slave(struct w1_slave *sl) { struct w1_f1C_data *data = NULL; if (w1_enable_crccheck) { data = kzalloc(sizeof(struct w1_f1C_data), GFP_KERNEL); if (!data) return -ENOMEM; sl->family_data = data; } return 0; } static void w1_f1C_remove_slave(struct w1_slave *sl) { kfree(sl->family_data); sl->family_data = NULL; } static struct w1_family_ops w1_f1C_fops = { .add_slave = w1_f1C_add_slave, .remove_slave = w1_f1C_remove_slave, .groups = w1_f1C_groups, }; static struct w1_family w1_family_1C = { .fid = W1_FAMILY_DS28E04, .fops = &w1_f1C_fops, }; module_w1_family(w1_family_1C); MODULE_AUTHOR("Markus Franke <franke.m@sebakmt.com>, <franm@hrz.tu-chemnitz.de>"); MODULE_DESCRIPTION("w1 family 1C driver for DS28E04, 4kb EEPROM and PIO"); MODULE_LICENSE("GPL"); MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS28E04));
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