diff options
Diffstat (limited to 'drivers/w1/slaves/w1_ds2408.c')
| -rw-r--r-- | drivers/w1/slaves/w1_ds2408.c | 402 |
1 files changed, 402 insertions, 0 deletions
diff --git a/drivers/w1/slaves/w1_ds2408.c b/drivers/w1/slaves/w1_ds2408.c new file mode 100644 index 000000000000..c37781899d90 --- /dev/null +++ b/drivers/w1/slaves/w1_ds2408.c @@ -0,0 +1,402 @@ +/* + * w1_ds2408.c - w1 family 29 (DS2408) driver + * + * Copyright (c) 2010 Jean-Francois Dagenais <dagenaisj@sonatest.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 "../w1.h" +#include "../w1_int.h" +#include "../w1_family.h" + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Jean-Francois Dagenais <dagenaisj@sonatest.com>"); +MODULE_DESCRIPTION("w1 family 29 driver for DS2408 8 Pin IO"); + + +#define W1_F29_RETRIES 3 + +#define W1_F29_REG_LOGIG_STATE 0x88 /* R */ +#define W1_F29_REG_OUTPUT_LATCH_STATE 0x89 /* R */ +#define W1_F29_REG_ACTIVITY_LATCH_STATE 0x8A /* R */ +#define W1_F29_REG_COND_SEARCH_SELECT_MASK 0x8B /* RW */ +#define W1_F29_REG_COND_SEARCH_POL_SELECT 0x8C /* RW */ +#define W1_F29_REG_CONTROL_AND_STATUS 0x8D /* RW */ + +#define W1_F29_FUNC_READ_PIO_REGS 0xF0 +#define W1_F29_FUNC_CHANN_ACCESS_READ 0xF5 +#define W1_F29_FUNC_CHANN_ACCESS_WRITE 0x5A +/* also used to write the control/status reg (0x8D): */ +#define W1_F29_FUNC_WRITE_COND_SEARCH_REG 0xCC +#define W1_F29_FUNC_RESET_ACTIVITY_LATCHES 0xC3 + +#define W1_F29_SUCCESS_CONFIRM_BYTE 0xAA + +static int _read_reg(struct w1_slave *sl, u8 address, unsigned char* buf) +{ + u8 wrbuf[3]; + dev_dbg(&sl->dev, + "Reading with slave: %p, reg addr: %0#4x, buff addr: %p", + sl, (unsigned int)address, buf); + + if (!buf) + return -EINVAL; + + mutex_lock(&sl->master->mutex); + dev_dbg(&sl->dev, "mutex locked"); + + if (w1_reset_select_slave(sl)) { + mutex_unlock(&sl->master->mutex); + return -EIO; + } + + wrbuf[0] = W1_F29_FUNC_READ_PIO_REGS; + wrbuf[1] = address; + wrbuf[2] = 0; + w1_write_block(sl->master, wrbuf, 3); + *buf = w1_read_8(sl->master); + + mutex_unlock(&sl->master->mutex); + dev_dbg(&sl->dev, "mutex unlocked"); + return 1; +} + +static ssize_t w1_f29_read_state( + struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + dev_dbg(&kobj_to_w1_slave(kobj)->dev, + "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", + bin_attr->attr.name, kobj, (unsigned int)off, count, buf); + if (count != 1 || off != 0) + return -EFAULT; + return _read_reg(kobj_to_w1_slave(kobj), W1_F29_REG_LOGIG_STATE, buf); +} + +static ssize_t w1_f29_read_output( + struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + dev_dbg(&kobj_to_w1_slave(kobj)->dev, + "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", + bin_attr->attr.name, kobj, (unsigned int)off, count, buf); + if (count != 1 || off != 0) + return -EFAULT; + return _read_reg(kobj_to_w1_slave(kobj), + W1_F29_REG_OUTPUT_LATCH_STATE, buf); +} + +static ssize_t w1_f29_read_activity( + struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + dev_dbg(&kobj_to_w1_slave(kobj)->dev, + "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", + bin_attr->attr.name, kobj, (unsigned int)off, count, buf); + if (count != 1 || off != 0) + return -EFAULT; + return _read_reg(kobj_to_w1_slave(kobj), + W1_F29_REG_ACTIVITY_LATCH_STATE, buf); +} + +static ssize_t w1_f29_read_cond_search_mask( + struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + dev_dbg(&kobj_to_w1_slave(kobj)->dev, + "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", + bin_attr->attr.name, kobj, (unsigned int)off, count, buf); + if (count != 1 || off != 0) + return -EFAULT; + return _read_reg(kobj_to_w1_slave(kobj), + W1_F29_REG_COND_SEARCH_SELECT_MASK, buf); +} + +static ssize_t w1_f29_read_cond_search_polarity( + struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + if (count != 1 || off != 0) + return -EFAULT; + return _read_reg(kobj_to_w1_slave(kobj), + W1_F29_REG_COND_SEARCH_POL_SELECT, buf); +} + +static ssize_t w1_f29_read_status_control( + struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + if (count != 1 || off != 0) + return -EFAULT; + return _read_reg(kobj_to_w1_slave(kobj), + W1_F29_REG_CONTROL_AND_STATUS, buf); +} + + + + +static ssize_t w1_f29_write_output( + 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 w1_buf[3]; + u8 readBack; + unsigned int retries = W1_F29_RETRIES; + + if (count != 1 || off != 0) + return -EFAULT; + + dev_dbg(&sl->dev, "locking mutex for write_output"); + mutex_lock(&sl->master->mutex); + dev_dbg(&sl->dev, "mutex locked"); + + if (w1_reset_select_slave(sl)) + goto error; + + while (retries--) { + w1_buf[0] = W1_F29_FUNC_CHANN_ACCESS_WRITE; + w1_buf[1] = *buf; + w1_buf[2] = ~(*buf); + w1_write_block(sl->master, w1_buf, 3); + + readBack = w1_read_8(sl->master); + /* here the master could read another byte which + would be the PIO reg (the actual pin logic state) + since in this driver we don't know which pins are + in and outs, there's no value to read the state and + compare. with (*buf) so end this command abruptly: */ + if (w1_reset_resume_command(sl->master)) + goto error; + + if (readBack != 0xAA) { + /* try again, the slave is ready for a command */ + continue; + } + + /* go read back the output latches */ + /* (the direct effect of the write above) */ + w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS; + w1_buf[1] = W1_F29_REG_OUTPUT_LATCH_STATE; + w1_buf[2] = 0; + w1_write_block(sl->master, w1_buf, 3); + /* read the result of the READ_PIO_REGS command */ + if (w1_read_8(sl->master) == *buf) { + /* success! */ + mutex_unlock(&sl->master->mutex); + dev_dbg(&sl->dev, + "mutex unlocked, retries:%d", retries); + return 1; + } + } +error: + mutex_unlock(&sl->master->mutex); + dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries); + + return -EIO; +} + + +/** + * Writing to the activity file resets the activity latches. + */ +static ssize_t w1_f29_write_activity( + 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); + unsigned int retries = W1_F29_RETRIES; + + if (count != 1 || off != 0) + return -EFAULT; + + mutex_lock(&sl->master->mutex); + + if (w1_reset_select_slave(sl)) + goto error; + + while (retries--) { + w1_write_8(sl->master, W1_F29_FUNC_RESET_ACTIVITY_LATCHES); + if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE) { + mutex_unlock(&sl->master->mutex); + return 1; + } + if (w1_reset_resume_command(sl->master)) + goto error; + } + +error: + mutex_unlock(&sl->master->mutex); + return -EIO; +} + +static ssize_t w1_f29_write_status_control( + 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 w1_buf[4]; + unsigned int retries = W1_F29_RETRIES; + + if (count != 1 || off != 0) + return -EFAULT; + + mutex_lock(&sl->master->mutex); + + if (w1_reset_select_slave(sl)) + goto error; + + while (retries--) { + w1_buf[0] = W1_F29_FUNC_WRITE_COND_SEARCH_REG; + w1_buf[1] = W1_F29_REG_CONTROL_AND_STATUS; + w1_buf[2] = 0; + w1_buf[3] = *buf; + + w1_write_block(sl->master, w1_buf, 4); + if (w1_reset_resume_command(sl->master)) + goto error; + + w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS; + w1_buf[1] = W1_F29_REG_CONTROL_AND_STATUS; + w1_buf[2] = 0; + + w1_write_block(sl->master, w1_buf, 3); + if (w1_read_8(sl->master) == *buf) { + /* success! */ + mutex_unlock(&sl->master->mutex); + return 1; + } + } +error: + mutex_unlock(&sl->master->mutex); + + return -EIO; +} + + + +#define NB_SYSFS_BIN_FILES 6 +static struct bin_attribute w1_f29_sysfs_bin_files[NB_SYSFS_BIN_FILES] = { + { + .attr = { + .name = "state", + .mode = S_IRUGO, + }, + .size = 1, + .read = w1_f29_read_state, + }, + { + .attr = { + .name = "output", + .mode = S_IRUGO | S_IWUSR | S_IWGRP, + }, + .size = 1, + .read = w1_f29_read_output, + .write = w1_f29_write_output, + }, + { + .attr = { + .name = "activity", + .mode = S_IRUGO, + }, + .size = 1, + .read = w1_f29_read_activity, + .write = w1_f29_write_activity, + }, + { + .attr = { + .name = "cond_search_mask", + .mode = S_IRUGO, + }, + .size = 1, + .read = w1_f29_read_cond_search_mask, + .write = 0, + }, + { + .attr = { + .name = "cond_search_polarity", + .mode = S_IRUGO, + }, + .size = 1, + .read = w1_f29_read_cond_search_polarity, + .write = 0, + }, + { + .attr = { + .name = "status_control", + .mode = S_IRUGO | S_IWUSR | S_IWGRP, + }, + .size = 1, + .read = w1_f29_read_status_control, + .write = w1_f29_write_status_control, + } +}; + +static int w1_f29_add_slave(struct w1_slave *sl) +{ + int err = 0; + int i; + + for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i) + err = sysfs_create_bin_file( + &sl->dev.kobj, + &(w1_f29_sysfs_bin_files[i])); + if (err) + while (--i >= 0) + sysfs_remove_bin_file(&sl->dev.kobj, + &(w1_f29_sysfs_bin_files[i])); + return err; +} + +static void w1_f29_remove_slave(struct w1_slave *sl) +{ + int i; + for (i = NB_SYSFS_BIN_FILES; i <= 0; --i) + sysfs_remove_bin_file(&sl->dev.kobj, + &(w1_f29_sysfs_bin_files[i])); +} + +static struct w1_family_ops w1_f29_fops = { + .add_slave = w1_f29_add_slave, + .remove_slave = w1_f29_remove_slave, +}; + +static struct w1_family w1_family_29 = { + .fid = W1_FAMILY_DS2408, + .fops = &w1_f29_fops, +}; + +static int __init w1_f29_init(void) +{ + return w1_register_family(&w1_family_29); +} + +static void __exit w1_f29_exit(void) +{ + w1_unregister_family(&w1_family_29); +} + +module_init(w1_f29_init); +module_exit(w1_f29_exit); |