218 lines
4.6 KiB
C
218 lines
4.6 KiB
C
/*
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* w1_ds2433.c - w1 family 23 (DS2433) driver
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*
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* Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
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*
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* This source code is licensed under the GNU General Public License,
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* Version 2. See the file COPYING for more details.
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*/
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#include <init.h>
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#include "../w1.h"
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#define W1_PAGE_SIZE 32
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#define W1_PAGE_BITS 5
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#define W1_PAGE_MASK 0x1F
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#define W1_F23_TIME 300
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#define W1_F23_READ_EEPROM 0xF0
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#define W1_F23_WRITE_SCRATCH 0x0F
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#define W1_F23_READ_SCRATCH 0xAA
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#define W1_F23_COPY_SCRATCH 0x55
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static int ds2433_count = 0;
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static int ds28ec20_count = 0;
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/**
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* Check the file size bounds and adjusts count as needed.
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* This would not be needed if the file size didn't reset to 0 after a write.
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*/
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static inline size_t ds2433_fix_count(loff_t off, size_t count, size_t size)
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{
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if (off > size)
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return 0;
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if ((off + count) > size)
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return (size - off);
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return count;
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}
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static ssize_t ds2433_cdev_read(struct cdev *cdev, void *buf, size_t count,
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loff_t off, ulong flags)
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{
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struct w1_device *dev = cdev->priv;
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struct w1_bus *bus = dev->bus;
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u8 wrbuf[3];
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if ((count = ds2433_fix_count(off, count, cdev->size)) == 0)
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return 0;
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/* read directly from the EEPROM */
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if (w1_reset_select_slave(dev)) {
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count = -EIO;
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goto out_up;
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}
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wrbuf[0] = W1_F23_READ_EEPROM;
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wrbuf[1] = off & 0xff;
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wrbuf[2] = off >> 8;
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w1_write_block(bus, wrbuf, 3);
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w1_read_block(bus, buf, count);
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out_up:
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return count;
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}
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#ifdef CONFIG_W1_SLAVE_DS2433_WRITE
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/**
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* Writes to the scratchpad and reads it back for verification.
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* Then copies the scratchpad to EEPROM.
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* The data must be on one page.
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* The master must be locked.
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*
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* @param sl The slave structure
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* @param addr Address for the write
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* @param len length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK))
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* @param data The data to write
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* @return 0=Success -1=failure
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*/
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static int ds2433_write(struct w1_device *dev, int addr, int len, const u8 *data)
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{
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struct w1_bus *bus = dev->bus;
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u8 wrbuf[4];
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u8 rdbuf[W1_PAGE_SIZE + 3];
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u8 es = (addr + len - 1) & 0x1f;
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/* Write the data to the scratchpad */
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if (w1_reset_select_slave(dev))
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return -1;
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wrbuf[0] = W1_F23_WRITE_SCRATCH;
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wrbuf[1] = addr & 0xff;
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wrbuf[2] = addr >> 8;
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w1_write_block(bus, wrbuf, 3);
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w1_write_block(bus, data, len);
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/* Read the scratchpad and verify */
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if (w1_reset_select_slave(dev))
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return -1;
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w1_write_8(bus, W1_F23_READ_SCRATCH);
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w1_read_block(bus, rdbuf, len + 3);
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/* Compare what was read against the data written */
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if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) ||
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(rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0))
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return -1;
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/* Copy the scratchpad to EEPROM */
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if (w1_reset_select_slave(dev))
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return -1;
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wrbuf[0] = W1_F23_COPY_SCRATCH;
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wrbuf[3] = es;
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w1_write_block(bus, wrbuf, 4);
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/* Sleep for 5 ms to wait for the write to complete */
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mdelay(5);
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/* Reset the bus to wake up the EEPROM (this may not be needed) */
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w1_reset_bus(bus);
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return 0;
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}
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static ssize_t ds2433_cdev_write(struct cdev *cdev, const void *buf, size_t count,
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loff_t off, ulong flags)
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{
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struct w1_device *dev = cdev->priv;
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int addr, len, idx;
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const u8 *buf8 = buf;
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if ((count = ds2433_fix_count(off, count, cdev->size)) == 0)
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return 0;
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/* Can only write data to one page at a time */
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idx = 0;
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while (idx < count) {
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addr = off + idx;
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len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
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if (len > (count - idx))
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len = count - idx;
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if (ds2433_write(dev, addr, len, &buf8[idx]) < 0) {
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count = -EIO;
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goto out_up;
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}
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idx += len;
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}
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out_up:
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return count;
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}
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#else
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#define ds2433_cdev_write NULL
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#endif
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static struct file_operations ds2433_ops = {
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.read = ds2433_cdev_read,
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.write = ds2433_cdev_write,
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.lseek = dev_lseek_default,
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};
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static int ds2433_cdev_create(struct w1_device *dev, int size, int id)
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{
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struct cdev *cdev;
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cdev = xzalloc(sizeof(*cdev));
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cdev->dev = &dev->dev;
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cdev->priv = dev;
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cdev->ops = &ds2433_ops;
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cdev->size = size;
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cdev->name = asprintf("%s%d", dev->dev.driver->name, id);
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if (cdev->name == NULL)
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return -ENOMEM;
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return devfs_create(cdev);
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}
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static int ds2433_probe(struct w1_device *dev)
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{
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return ds2433_cdev_create(dev, 512, ds2433_count++);
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}
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static int ds28ec20_probe(struct w1_device *dev)
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{
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return ds2433_cdev_create(dev, 2560, ds28ec20_count++);
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}
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struct w1_driver ds2433_driver = {
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.drv = {
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.name = "ds2433",
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},
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.probe = ds2433_probe,
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.fid = 0x23,
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};
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struct w1_driver ds28ec20_driver = {
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.drv = {
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.name = "ds28ec20",
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},
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.probe = ds28ec20_probe,
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.fid = 0x43,
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};
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static int w1_ds2433_init(void)
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{
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int ret;
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ret = w1_driver_register(&ds2433_driver);
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if (ret)
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return ret;
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return w1_driver_register(&ds28ec20_driver);
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}
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device_initcall(w1_ds2433_init);
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