From bd529cfb40c427d5b5aae0d315afb9f0a1da5e76 Mon Sep 17 00:00:00 2001 From: Evgeniy Polyakov Date: Tue, 6 Dec 2005 13:38:28 +0300 Subject: [PATCH] W1: Move w1 bus master code into 'w1/masters' and move w1 slave code into 'w1/slaves' Signed-off-by: Ben Gardner Signed-off-by: Evgeniy Polyakov Signed-off-by: Greg Kroah-Hartman --- drivers/w1/slaves/w1_ds2433.c | 329 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 329 insertions(+) create mode 100644 drivers/w1/slaves/w1_ds2433.c (limited to 'drivers/w1/slaves/w1_ds2433.c') diff --git a/drivers/w1/slaves/w1_ds2433.c b/drivers/w1/slaves/w1_ds2433.c new file mode 100644 index 00000000000..fb118be789e --- /dev/null +++ b/drivers/w1/slaves/w1_ds2433.c @@ -0,0 +1,329 @@ +/* + * w1_ds2433.c - w1 family 23 (DS2433) driver + * + * Copyright (c) 2005 Ben Gardner + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + +#include +#include +#include +#include +#include +#include +#ifdef CONFIG_W1_F23_CRC +#include + +#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 "); +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); -- cgit v1.2.3