--- /dev/null
+/*
+ * 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>
+#ifdef CONFIG_W1_F23_CRC
+#include <linux/crc16.h>
+
+#define CRC16_INIT 0
+#define CRC16_VALID 0xb001
+
+#endif
+
+#include "w1.h"
+#include "w1_io.h"
+#include "w1_int.h"
+#include "w1_family.h"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
+MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM");
+
+#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_F23_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_F23_CRC */
+
+static ssize_t w1_f23_read_bin(struct kobject *kobj, char *buf, loff_t off,
+ size_t count)
+{
+ struct w1_slave *sl = kobj_to_w1_slave(kobj);
+#ifdef CONFIG_W1_F23_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;
+
+ atomic_inc(&sl->refcnt);
+ if (down_interruptible(&sl->master->mutex)) {
+ count = 0;
+ goto out_dec;
+ }
+
+#ifdef CONFIG_W1_F23_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_F23_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_F23_CRC */
+
+out_up:
+ up(&sl->master->mutex);
+out_dec:
+ atomic_dec(&sl->refcnt);
+
+ 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)
+{
+ 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);
+
+ return 0;
+}
+
+static ssize_t w1_f23_write_bin(struct kobject *kobj, 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_F23_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_F23_CRC */
+
+ atomic_inc(&sl->refcnt);
+ if (down_interruptible(&sl->master->mutex)) {
+ count = 0;
+ goto out_dec;
+ }
+
+ /* 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:
+ up(&sl->master->mutex);
+out_dec:
+ atomic_dec(&sl->refcnt);
+
+ return count;
+}
+
+static struct bin_attribute w1_f23_bin_attr = {
+ .attr = {
+ .name = "eeprom",
+ .mode = S_IRUGO | S_IWUSR,
+ .owner = THIS_MODULE,
+ },
+ .size = W1_EEPROM_SIZE,
+ .read = w1_f23_read_bin,
+ .write = w1_f23_write_bin,
+};
+
+static int w1_f23_add_slave(struct w1_slave *sl)
+{
+ int err;
+#ifdef CONFIG_W1_F23_CRC
+ struct w1_f23_data *data;
+
+ data = kmalloc(sizeof(struct w1_f23_data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ memset(data, 0, sizeof(struct w1_f23_data));
+ sl->family_data = data;
+
+#endif /* CONFIG_W1_F23_CRC */
+
+ err = sysfs_create_bin_file(&sl->dev.kobj, &w1_f23_bin_attr);
+
+#ifdef CONFIG_W1_F23_CRC
+ if (err)
+ kfree(data);
+#endif /* CONFIG_W1_F23_CRC */
+
+ return err;
+}
+
+static void w1_f23_remove_slave(struct w1_slave *sl)
+{
+#ifdef CONFIG_W1_F23_CRC
+ kfree(sl->family_data);
+ sl->family_data = NULL;
+#endif /* CONFIG_W1_F23_CRC */
+ sysfs_remove_bin_file(&sl->dev.kobj, &w1_f23_bin_attr);
+}
+
+static struct w1_family_ops w1_f23_fops = {
+ .add_slave = w1_f23_add_slave,
+ .remove_slave = w1_f23_remove_slave,
+};
+
+static struct w1_family w1_family_23 = {
+ .fid = W1_EEPROM_DS2433,
+ .fops = &w1_f23_fops,
+};
+
+static int __init w1_f23_init(void)
+{
+ return w1_register_family(&w1_family_23);
+}
+
+static void __exit w1_f23_fini(void)
+{
+ w1_unregister_family(&w1_family_23);
+}
+
+module_init(w1_f23_init);
+module_exit(w1_f23_fini);
git://git.onelab.eu / linux-2.6.git / blobdiff