| /* |
| * 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->bus_mutex); |
| dev_dbg(&sl->dev, "mutex locked"); |
| |
| if (w1_reset_select_slave(sl)) { |
| mutex_unlock(&sl->master->bus_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->bus_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->bus_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->bus_mutex); |
| dev_dbg(&sl->dev, |
| "mutex unlocked, retries:%d", retries); |
| return 1; |
| } |
| } |
| error: |
| mutex_unlock(&sl->master->bus_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->bus_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->bus_mutex); |
| return 1; |
| } |
| if (w1_reset_resume_command(sl->master)) |
| goto error; |
| } |
| |
| error: |
| mutex_unlock(&sl->master->bus_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->bus_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->bus_mutex); |
| return 1; |
| } |
| } |
| error: |
| mutex_unlock(&sl->master->bus_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, |
| }, |
| { |
| .attr = { |
| .name = "cond_search_polarity", |
| .mode = S_IRUGO, |
| }, |
| .size = 1, |
| .read = w1_f29_read_cond_search_polarity, |
| }, |
| { |
| .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 - 1; 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); |
