From 0dd4dae3071d135836946ab1b990061c0899e9b5 Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Mon, 13 Jul 2015 13:25:31 +0100 Subject: [PATCH 119/121] Merge pull request #1059 from pelwell/rpi-4.0.y w1_therm: Back-port locking improvements from 4.2-rc1 --- Documentation/ABI/stable/sysfs-driver-w1_ds28ea00 | 6 + Documentation/w1/slaves/w1_therm | 11 +- drivers/w1/slaves/w1_therm.c | 162 ++++++++++++++++++++-- 3 files changed, 163 insertions(+), 16 deletions(-) create mode 100644 Documentation/ABI/stable/sysfs-driver-w1_ds28ea00 --- /dev/null +++ b/Documentation/ABI/stable/sysfs-driver-w1_ds28ea00 @@ -0,0 +1,6 @@ +What: /sys/bus/w1/devices/.../w1_seq +Date: Apr 2015 +Contact: Matt Campbell +Description: Support for the DS28EA00 chain sequence function + see Documentation/w1/slaves/w1_therm for detailed information +Users: any user space application which wants to communicate with DS28EA00 --- a/Documentation/w1/slaves/w1_therm +++ b/Documentation/w1/slaves/w1_therm @@ -11,12 +11,14 @@ Author: Evgeniy Polyakov refcnt) + static int w1_therm_add_slave(struct w1_slave *sl) { - sl->family_data = kzalloc(9, GFP_KERNEL); + sl->family_data = kzalloc(sizeof(struct w1_therm_family_data), + GFP_KERNEL); if (!sl->family_data) return -ENOMEM; + atomic_set(THERM_REFCNT(sl->family_data), 1); return 0; } static void w1_therm_remove_slave(struct w1_slave *sl) { + int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data)); + while(refcnt) { + msleep(1000); + refcnt = atomic_read(THERM_REFCNT(sl->family_data)); + } kfree(sl->family_data); sl->family_data = NULL; } @@ -76,13 +92,24 @@ static void w1_therm_remove_slave(struct static ssize_t w1_slave_show(struct device *device, struct device_attribute *attr, char *buf); +static ssize_t w1_seq_show(struct device *device, + struct device_attribute *attr, char *buf); + static DEVICE_ATTR_RO(w1_slave); +static DEVICE_ATTR_RO(w1_seq); static struct attribute *w1_therm_attrs[] = { &dev_attr_w1_slave.attr, NULL, }; + +static struct attribute *w1_ds28ea00_attrs[] = { + &dev_attr_w1_slave.attr, + &dev_attr_w1_seq.attr, + NULL, +}; ATTRIBUTE_GROUPS(w1_therm); +ATTRIBUTE_GROUPS(w1_ds28ea00); static struct w1_family_ops w1_therm_fops = { .add_slave = w1_therm_add_slave, @@ -90,6 +117,12 @@ static struct w1_family_ops w1_therm_fop .groups = w1_therm_groups, }; +static struct w1_family_ops w1_ds28ea00_fops = { + .add_slave = w1_therm_add_slave, + .remove_slave = w1_therm_remove_slave, + .groups = w1_ds28ea00_groups, +}; + static struct w1_family w1_therm_family_DS18S20 = { .fid = W1_THERM_DS18S20, .fops = &w1_therm_fops, @@ -107,7 +140,7 @@ static struct w1_family w1_therm_family_ static struct w1_family w1_therm_family_DS28EA00 = { .fid = W1_THERM_DS28EA00, - .fops = &w1_therm_fops, + .fops = &w1_ds28ea00_fops, }; static struct w1_family w1_therm_family_DS1825 = { @@ -194,13 +227,22 @@ static ssize_t w1_slave_show(struct devi struct w1_slave *sl = dev_to_w1_slave(device); struct w1_master *dev = sl->master; u8 rom[9], crc, verdict, external_power; - int i, max_trying = 10; + int i, ret, max_trying = 10; ssize_t c = PAGE_SIZE; + u8 *family_data = sl->family_data; - i = mutex_lock_interruptible(&dev->bus_mutex); - if (i != 0) - return i; + ret = mutex_lock_interruptible(&dev->bus_mutex); + if (ret != 0) + goto post_unlock; + + if(!sl->family_data) + { + ret = -ENODEV; + goto pre_unlock; + } + /* prevent the slave from going away in sleep */ + atomic_inc(THERM_REFCNT(family_data)); memset(rom, 0, sizeof(rom)); while (max_trying--) { @@ -230,17 +272,19 @@ static ssize_t w1_slave_show(struct devi mutex_unlock(&dev->bus_mutex); sleep_rem = msleep_interruptible(tm); - if (sleep_rem != 0) - return -EINTR; + if (sleep_rem != 0) { + ret = -EINTR; + goto post_unlock; + } - i = mutex_lock_interruptible(&dev->bus_mutex); - if (i != 0) - return i; + ret = mutex_lock_interruptible(&dev->bus_mutex); + if (ret != 0) + goto post_unlock; } else if (!w1_strong_pullup) { sleep_rem = msleep_interruptible(tm); if (sleep_rem != 0) { - mutex_unlock(&dev->bus_mutex); - return -EINTR; + ret = -EINTR; + goto pre_unlock; } } @@ -269,19 +313,107 @@ static ssize_t w1_slave_show(struct devi c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n", crc, (verdict) ? "YES" : "NO"); if (verdict) - memcpy(sl->family_data, rom, sizeof(rom)); + memcpy(family_data, rom, sizeof(rom)); else dev_warn(device, "Read failed CRC check\n"); for (i = 0; i < 9; ++i) c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", - ((u8 *)sl->family_data)[i]); + ((u8 *)family_data)[i]); c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n", w1_convert_temp(rom, sl->family->fid)); + ret = PAGE_SIZE - c; + +pre_unlock: mutex_unlock(&dev->bus_mutex); +post_unlock: + atomic_dec(THERM_REFCNT(family_data)); + return ret; +} + +#define W1_42_CHAIN 0x99 +#define W1_42_CHAIN_OFF 0x3C +#define W1_42_CHAIN_OFF_INV 0xC3 +#define W1_42_CHAIN_ON 0x5A +#define W1_42_CHAIN_ON_INV 0xA5 +#define W1_42_CHAIN_DONE 0x96 +#define W1_42_CHAIN_DONE_INV 0x69 +#define W1_42_COND_READ 0x0F +#define W1_42_SUCCESS_CONFIRM_BYTE 0xAA +#define W1_42_FINISHED_BYTE 0xFF +static ssize_t w1_seq_show(struct device *device, + struct device_attribute *attr, char *buf) +{ + struct w1_slave *sl = dev_to_w1_slave(device); + ssize_t c = PAGE_SIZE; + int rv; + int i; + u8 ack; + u64 rn; + struct w1_reg_num *reg_num; + int seq = 0; + + mutex_lock(&sl->master->bus_mutex); + /* Place all devices in CHAIN state */ + if (w1_reset_bus(sl->master)) + goto error; + w1_write_8(sl->master, W1_SKIP_ROM); + w1_write_8(sl->master, W1_42_CHAIN); + w1_write_8(sl->master, W1_42_CHAIN_ON); + w1_write_8(sl->master, W1_42_CHAIN_ON_INV); + msleep(sl->master->pullup_duration); + + /* check for acknowledgment */ + ack = w1_read_8(sl->master); + if (ack != W1_42_SUCCESS_CONFIRM_BYTE) + goto error; + + /* In case the bus fails to send 0xFF, limit*/ + for (i = 0; i <= 64; i++) { + if (w1_reset_bus(sl->master)) + goto error; + + w1_write_8(sl->master, W1_42_COND_READ); + rv = w1_read_block(sl->master, (u8 *)&rn, 8); + reg_num = (struct w1_reg_num *) &rn; + if (reg_num->family == W1_42_FINISHED_BYTE) + break; + if (sl->reg_num.id == reg_num->id) + seq = i; + + w1_write_8(sl->master, W1_42_CHAIN); + w1_write_8(sl->master, W1_42_CHAIN_DONE); + w1_write_8(sl->master, W1_42_CHAIN_DONE_INV); + w1_read_block(sl->master, &ack, sizeof(ack)); + + /* check for acknowledgment */ + ack = w1_read_8(sl->master); + if (ack != W1_42_SUCCESS_CONFIRM_BYTE) + goto error; + + } + + /* Exit from CHAIN state */ + if (w1_reset_bus(sl->master)) + goto error; + w1_write_8(sl->master, W1_SKIP_ROM); + w1_write_8(sl->master, W1_42_CHAIN); + w1_write_8(sl->master, W1_42_CHAIN_OFF); + w1_write_8(sl->master, W1_42_CHAIN_OFF_INV); + + /* check for acknowledgment */ + ack = w1_read_8(sl->master); + if (ack != W1_42_SUCCESS_CONFIRM_BYTE) + goto error; + mutex_unlock(&sl->master->bus_mutex); + + c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq); return PAGE_SIZE - c; +error: + mutex_unlock(&sl->master->bus_mutex); + return -EIO; } static int __init w1_therm_init(void)