linux/drivers/w1/slaves/w1_ds2433.c

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/*
* w1_ds2433.c - w1 family 23 (DS2433) driver
*
* Copyright (c) 2005 Ben Gardner <bgardner@wabtec.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 cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
#include <linux/crc16.h>
#define CRC16_INIT 0
#define CRC16_VALID 0xb001
#endif
#include "../w1.h"
#include "../w1_int.h"
#include "../w1_family.h"
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM");
MODULE_ALIAS("w1-family-" __stringify(W1_EEPROM_DS2433));
#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_SLAVE_DS2433_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_SLAVE_DS2433_CRC */
static ssize_t w1_f23_read_bin(struct file *filp, struct kobject *kobj,
sysfs: add parameter "struct bin_attribute *" in .read/.write methods for sysfs binary attributes Well, first of all, I don't want to change so many files either. What I do: Adding a new parameter "struct bin_attribute *" in the .read/.write methods for the sysfs binary attributes. In fact, only the four lines change in fs/sysfs/bin.c and include/linux/sysfs.h do the real work. But I have to update all the files that use binary attributes to make them compatible with the new .read and .write methods. I'm not sure if I missed any. :( Why I do this: For a sysfs attribute, we can get a pointer pointing to the struct attribute in the .show/.store method, while we can't do this for the binary attributes. I don't know why this is different, but this does make it not so handy to use the binary attributes as the regular ones. So I think this patch is reasonable. :) Who benefits from it: The patch that exposes ACPI tables in sysfs requires such an improvement. All the table binary attributes share the same .read method. Parameter "struct bin_attribute *" is used to get the table signature and instance number which are used to distinguish different ACPI table binary attributes. Without this parameter, we need to offer different .read methods for different ACPI table binary attributes. This is impossible as there are various ACPI tables on different platforms, and we don't know what they are until they are loaded. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-06-09 05:57:22 +00:00
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
struct w1_slave *sl = kobj_to_w1_slave(kobj);
#ifdef CONFIG_W1_SLAVE_DS2433_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;
W1: split master mutex to avoid deadlocks. The 'mutex' in struct w1_master is use for two very different purposes. Firstly it protects various data structures such as the list of all slaves. Secondly it protects the w1 buss against concurrent accesses. This can lead to deadlocks when the ->probe code called while adding a slave needs to talk on the bus, as is the case for power_supply devices. ds2780 and ds2781 drivers contain a work around to track which process hold the lock simply to avoid this deadlock. bq27000 doesn't have that work around and so deadlocks. There are other possible deadlocks involving sysfs. When removing a device the sysfs s_active lock is held, so the lock that protects the slave list must take precedence over s_active. However when access power_supply attributes via sysfs, the s_active lock must take precedence over the lock that protects accesses to the bus. So to avoid deadlocks between w1 slaves and sysfs, these must be two separate locks. Making them separate means that the work around in ds2780 and ds2781 can be removed. So this patch: - adds a new mutex: "bus_mutex" which serialises access to the bus. - takes in mutex in w1_search and ds1wm_search while they access the bus for searching. The mutex is dropped before calling the callback which adds the slave. - changes all slaves to use bus_mutex instead of mutex to protect access to the bus - removes w1_ds2790_io_nolock and w1_ds2781_io_nolock, and the related code from drivers/power/ds278[01]_battery.c which calls them. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-18 05:59:52 +00:00
mutex_lock(&sl->master->bus_mutex);
#ifdef CONFIG_W1_SLAVE_DS2433_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_SLAVE_DS2433_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_SLAVE_DS2433_CRC */
out_up:
W1: split master mutex to avoid deadlocks. The 'mutex' in struct w1_master is use for two very different purposes. Firstly it protects various data structures such as the list of all slaves. Secondly it protects the w1 buss against concurrent accesses. This can lead to deadlocks when the ->probe code called while adding a slave needs to talk on the bus, as is the case for power_supply devices. ds2780 and ds2781 drivers contain a work around to track which process hold the lock simply to avoid this deadlock. bq27000 doesn't have that work around and so deadlocks. There are other possible deadlocks involving sysfs. When removing a device the sysfs s_active lock is held, so the lock that protects the slave list must take precedence over s_active. However when access power_supply attributes via sysfs, the s_active lock must take precedence over the lock that protects accesses to the bus. So to avoid deadlocks between w1 slaves and sysfs, these must be two separate locks. Making them separate means that the work around in ds2780 and ds2781 can be removed. So this patch: - adds a new mutex: "bus_mutex" which serialises access to the bus. - takes in mutex in w1_search and ds1wm_search while they access the bus for searching. The mutex is dropped before calling the callback which adds the slave. - changes all slaves to use bus_mutex instead of mutex to protect access to the bus - removes w1_ds2790_io_nolock and w1_ds2781_io_nolock, and the related code from drivers/power/ds278[01]_battery.c which calls them. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-18 05:59:52 +00:00
mutex_unlock(&sl->master->bus_mutex);
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)
{
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
struct w1_f23_data *f23 = sl->family_data;
#endif
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);
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
f23->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
#endif
return 0;
}
static ssize_t w1_f23_write_bin(struct file *filp, struct kobject *kobj,
sysfs: add parameter "struct bin_attribute *" in .read/.write methods for sysfs binary attributes Well, first of all, I don't want to change so many files either. What I do: Adding a new parameter "struct bin_attribute *" in the .read/.write methods for the sysfs binary attributes. In fact, only the four lines change in fs/sysfs/bin.c and include/linux/sysfs.h do the real work. But I have to update all the files that use binary attributes to make them compatible with the new .read and .write methods. I'm not sure if I missed any. :( Why I do this: For a sysfs attribute, we can get a pointer pointing to the struct attribute in the .show/.store method, while we can't do this for the binary attributes. I don't know why this is different, but this does make it not so handy to use the binary attributes as the regular ones. So I think this patch is reasonable. :) Who benefits from it: The patch that exposes ACPI tables in sysfs requires such an improvement. All the table binary attributes share the same .read method. Parameter "struct bin_attribute *" is used to get the table signature and instance number which are used to distinguish different ACPI table binary attributes. Without this parameter, we need to offer different .read methods for different ACPI table binary attributes. This is impossible as there are various ACPI tables on different platforms, and we don't know what they are until they are loaded. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-06-09 05:57:22 +00:00
struct bin_attribute *bin_attr,
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_SLAVE_DS2433_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_SLAVE_DS2433_CRC */
W1: split master mutex to avoid deadlocks. The 'mutex' in struct w1_master is use for two very different purposes. Firstly it protects various data structures such as the list of all slaves. Secondly it protects the w1 buss against concurrent accesses. This can lead to deadlocks when the ->probe code called while adding a slave needs to talk on the bus, as is the case for power_supply devices. ds2780 and ds2781 drivers contain a work around to track which process hold the lock simply to avoid this deadlock. bq27000 doesn't have that work around and so deadlocks. There are other possible deadlocks involving sysfs. When removing a device the sysfs s_active lock is held, so the lock that protects the slave list must take precedence over s_active. However when access power_supply attributes via sysfs, the s_active lock must take precedence over the lock that protects accesses to the bus. So to avoid deadlocks between w1 slaves and sysfs, these must be two separate locks. Making them separate means that the work around in ds2780 and ds2781 can be removed. So this patch: - adds a new mutex: "bus_mutex" which serialises access to the bus. - takes in mutex in w1_search and ds1wm_search while they access the bus for searching. The mutex is dropped before calling the callback which adds the slave. - changes all slaves to use bus_mutex instead of mutex to protect access to the bus - removes w1_ds2790_io_nolock and w1_ds2781_io_nolock, and the related code from drivers/power/ds278[01]_battery.c which calls them. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-18 05:59:52 +00:00
mutex_lock(&sl->master->bus_mutex);
/* 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:
W1: split master mutex to avoid deadlocks. The 'mutex' in struct w1_master is use for two very different purposes. Firstly it protects various data structures such as the list of all slaves. Secondly it protects the w1 buss against concurrent accesses. This can lead to deadlocks when the ->probe code called while adding a slave needs to talk on the bus, as is the case for power_supply devices. ds2780 and ds2781 drivers contain a work around to track which process hold the lock simply to avoid this deadlock. bq27000 doesn't have that work around and so deadlocks. There are other possible deadlocks involving sysfs. When removing a device the sysfs s_active lock is held, so the lock that protects the slave list must take precedence over s_active. However when access power_supply attributes via sysfs, the s_active lock must take precedence over the lock that protects accesses to the bus. So to avoid deadlocks between w1 slaves and sysfs, these must be two separate locks. Making them separate means that the work around in ds2780 and ds2781 can be removed. So this patch: - adds a new mutex: "bus_mutex" which serialises access to the bus. - takes in mutex in w1_search and ds1wm_search while they access the bus for searching. The mutex is dropped before calling the callback which adds the slave. - changes all slaves to use bus_mutex instead of mutex to protect access to the bus - removes w1_ds2790_io_nolock and w1_ds2781_io_nolock, and the related code from drivers/power/ds278[01]_battery.c which calls them. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-18 05:59:52 +00:00
mutex_unlock(&sl->master->bus_mutex);
return count;
}
static struct bin_attribute w1_f23_bin_attr = {
.attr = {
.name = "eeprom",
.mode = S_IRUGO | S_IWUSR,
},
.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_SLAVE_DS2433_CRC
struct w1_f23_data *data;
2007-07-19 08:49:03 +00:00
data = kzalloc(sizeof(struct w1_f23_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
sl->family_data = data;
#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
err = sysfs_create_bin_file(&sl->dev.kobj, &w1_f23_bin_attr);
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
if (err)
kfree(data);
#endif /* CONFIG_W1_SLAVE_DS2433_CRC */
return err;
}
static void w1_f23_remove_slave(struct w1_slave *sl)
{
#ifdef CONFIG_W1_SLAVE_DS2433_CRC
kfree(sl->family_data);
sl->family_data = NULL;
#endif /* CONFIG_W1_SLAVE_DS2433_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);