+++ /dev/null
-/*
- * 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 "../w1.h"
-#include "../w1_int.h"
-#include "../w1_family.h"
-
-MODULE_LICENSE("GPL");
-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");
-
-/* 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 w1_f1C_read_bin(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;
-
- if ((count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE)) == 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 w1_f1C_write_bin(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_f1C_fix_count(off, count, W1_EEPROM_SIZE)) == 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 ssize_t w1_f1C_read_pio(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 w1_f1C_write_pio(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 ssize_t w1_f1C_show_crccheck(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 w1_f1C_store_crccheck(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);
-}
-
-#define NB_SYSFS_BIN_FILES 2
-static struct bin_attribute w1_f1C_bin_attr[NB_SYSFS_BIN_FILES] = {
- {
- .attr = {
- .name = "eeprom",
- .mode = S_IRUGO | S_IWUSR,
- },
- .size = W1_EEPROM_SIZE,
- .read = w1_f1C_read_bin,
- .write = w1_f1C_write_bin,
- },
- {
- .attr = {
- .name = "pio",
- .mode = S_IRUGO | S_IWUSR,
- },
- .size = 1,
- .read = w1_f1C_read_pio,
- .write = w1_f1C_write_pio,
- }
-};
-
-static DEVICE_ATTR(crccheck, S_IWUSR | S_IRUGO, w1_f1C_show_crccheck, w1_f1C_store_crccheck);
-
-static int w1_f1C_add_slave(struct w1_slave *sl)
-{
- int err = 0;
- int i;
- 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;
- }
-
- /* create binary sysfs attributes */
- for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)
- err = sysfs_create_bin_file(&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
-
- if(err)
- goto out;
-
- /* create device attributes */
- err = device_create_file(&sl->dev, &dev_attr_crccheck);
-
- if(err) {
- /* remove binary sysfs attributes */
- for (i = 0; i < NB_SYSFS_BIN_FILES; ++i)
- sysfs_remove_bin_file(&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
- }
-
-out:
- if(err) {
- if(w1_enable_crccheck)
- kfree(data);
- }
-
- return err;
-}
-
-static void w1_f1C_remove_slave(struct w1_slave *sl)
-{
- int i;
-
- if(w1_enable_crccheck) {
- kfree(sl->family_data);
- sl->family_data = NULL;
- }
-
- /* remove device attributes */
- device_remove_file(&sl->dev, &dev_attr_crccheck);
-
- /* remove binary sysfs attributes */
- for (i = 0; i < NB_SYSFS_BIN_FILES; ++i)
- sysfs_remove_bin_file(&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
-}
-
-static struct w1_family_ops w1_f1C_fops = {
- .add_slave = w1_f1C_add_slave,
- .remove_slave = w1_f1C_remove_slave,
-};
-
-static struct w1_family w1_family_1C = {
- .fid = W1_FAMILY_DS28E04,
- .fops = &w1_f1C_fops,
-};
-
-static int __init w1_f1C_init(void)
-{
- return w1_register_family(&w1_family_1C);
-}
-
-static void __exit w1_f1C_fini(void)
-{
- w1_unregister_family(&w1_family_1C);
-}
-
-module_init(w1_f1C_init);
-module_exit(w1_f1C_fini);
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