From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/w1/slaves/w1_ds2408.c | 353 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 353 insertions(+) create mode 100644 drivers/w1/slaves/w1_ds2408.c (limited to 'drivers/w1/slaves/w1_ds2408.c') diff --git a/drivers/w1/slaves/w1_ds2408.c b/drivers/w1/slaves/w1_ds2408.c new file mode 100644 index 000000000..56f822a1d --- /dev/null +++ b/drivers/w1/slaves/w1_ds2408.c @@ -0,0 +1,353 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * w1_ds2408.c - w1 family 29 (DS2408) driver + * + * Copyright (c) 2010 Jean-Francois Dagenais + */ + +#include +#include +#include +#include +#include +#include +#include + +#include + +#define W1_FAMILY_DS2408 0x29 + +#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 state_read(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 output_read(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 activity_read(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 cond_search_mask_read(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 cond_search_polarity_read(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 status_control_read(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); +} + +#ifdef CONFIG_W1_SLAVE_DS2408_READBACK +static bool optional_read_back_valid(struct w1_slave *sl, u8 expected) +{ + u8 w1_buf[3]; + + if (w1_reset_resume_command(sl->master)) + return false; + + 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); + + return (w1_read_8(sl->master) == expected); +} +#else +static bool optional_read_back_valid(struct w1_slave *sl, u8 expected) +{ + return true; +} +#endif + +static ssize_t output_write(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]; + unsigned int retries = W1_F29_RETRIES; + ssize_t bytes_written = -EIO; + + 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 out; + + do { + 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); + + if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE && + optional_read_back_valid(sl, *buf)) { + bytes_written = 1; + goto out; + } + + if (w1_reset_resume_command(sl->master)) + goto out; /* unrecoverable error */ + /* try again, the slave is ready for a command */ + } while (--retries); + +out: + mutex_unlock(&sl->master->bus_mutex); + + dev_dbg(&sl->dev, "%s, mutex unlocked retries:%d\n", + (bytes_written > 0) ? "succeeded" : "error", retries); + + return bytes_written; +} + + +/* + * Writing to the activity file resets the activity latches. + */ +static ssize_t activity_write(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 status_control_write(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; +} + +/* + * This is a special sequence we must do to ensure the P0 output is not stuck + * in test mode. This is described in rev 2 of the ds2408's datasheet + * (http://datasheets.maximintegrated.com/en/ds/DS2408.pdf) under + * "APPLICATION INFORMATION/Power-up timing". + */ +static int w1_f29_disable_test_mode(struct w1_slave *sl) +{ + int res; + u8 magic[10] = {0x96, }; + u64 rn = le64_to_cpu(*((u64 *)&sl->reg_num)); + + memcpy(&magic[1], &rn, 8); + magic[9] = 0x3C; + + mutex_lock(&sl->master->bus_mutex); + + res = w1_reset_bus(sl->master); + if (res) + goto out; + w1_write_block(sl->master, magic, ARRAY_SIZE(magic)); + + res = w1_reset_bus(sl->master); +out: + mutex_unlock(&sl->master->bus_mutex); + return res; +} + +static BIN_ATTR_RO(state, 1); +static BIN_ATTR_RW(output, 1); +static BIN_ATTR_RW(activity, 1); +static BIN_ATTR_RO(cond_search_mask, 1); +static BIN_ATTR_RO(cond_search_polarity, 1); +static BIN_ATTR_RW(status_control, 1); + +static struct bin_attribute *w1_f29_bin_attrs[] = { + &bin_attr_state, + &bin_attr_output, + &bin_attr_activity, + &bin_attr_cond_search_mask, + &bin_attr_cond_search_polarity, + &bin_attr_status_control, + NULL, +}; + +static const struct attribute_group w1_f29_group = { + .bin_attrs = w1_f29_bin_attrs, +}; + +static const struct attribute_group *w1_f29_groups[] = { + &w1_f29_group, + NULL, +}; + +static const struct w1_family_ops w1_f29_fops = { + .add_slave = w1_f29_disable_test_mode, + .groups = w1_f29_groups, +}; + +static struct w1_family w1_family_29 = { + .fid = W1_FAMILY_DS2408, + .fops = &w1_f29_fops, +}; +module_w1_family(w1_family_29); + +MODULE_AUTHOR("Jean-Francois Dagenais "); +MODULE_DESCRIPTION("w1 family 29 driver for DS2408 8 Pin IO"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2408)); -- cgit v1.2.3