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path: root/drivers/w1/slaves/w1_therm.c
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Diffstat (limited to 'drivers/w1/slaves/w1_therm.c')
-rw-r--r--drivers/w1/slaves/w1_therm.c268
1 files changed, 268 insertions, 0 deletions
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
new file mode 100644
index 00000000000..536d16d78de
--- /dev/null
+++ b/drivers/w1/slaves/w1_therm.c
@@ -0,0 +1,268 @@
+/*
+ * w1_therm.c
+ *
+ * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the therms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <asm/types.h>
+
+#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 "../w1.h"
+#include "../w1_io.h"
+#include "../w1_int.h"
+#include "../w1_family.h"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
+MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
+
+static u8 bad_roms[][9] = {
+ {0xaa, 0x00, 0x4b, 0x46, 0xff, 0xff, 0x0c, 0x10, 0x87},
+ {}
+ };
+
+static ssize_t w1_therm_read_bin(struct kobject *, char *, loff_t, size_t);
+
+static struct bin_attribute w1_therm_bin_attr = {
+ .attr = {
+ .name = "w1_slave",
+ .mode = S_IRUGO,
+ .owner = THIS_MODULE,
+ },
+ .size = W1_SLAVE_DATA_SIZE,
+ .read = w1_therm_read_bin,
+};
+
+static int w1_therm_add_slave(struct w1_slave *sl)
+{
+ return sysfs_create_bin_file(&sl->dev.kobj, &w1_therm_bin_attr);
+}
+
+static void w1_therm_remove_slave(struct w1_slave *sl)
+{
+ sysfs_remove_bin_file(&sl->dev.kobj, &w1_therm_bin_attr);
+}
+
+static struct w1_family_ops w1_therm_fops = {
+ .add_slave = w1_therm_add_slave,
+ .remove_slave = w1_therm_remove_slave,
+};
+
+static struct w1_family w1_therm_family_DS18S20 = {
+ .fid = W1_THERM_DS18S20,
+ .fops = &w1_therm_fops,
+};
+
+static struct w1_family w1_therm_family_DS18B20 = {
+ .fid = W1_THERM_DS18B20,
+ .fops = &w1_therm_fops,
+};
+
+static struct w1_family w1_therm_family_DS1822 = {
+ .fid = W1_THERM_DS1822,
+ .fops = &w1_therm_fops,
+};
+
+struct w1_therm_family_converter
+{
+ u8 broken;
+ u16 reserved;
+ struct w1_family *f;
+ int (*convert)(u8 rom[9]);
+};
+
+static inline int w1_DS18B20_convert_temp(u8 rom[9]);
+static inline int w1_DS18S20_convert_temp(u8 rom[9]);
+
+static struct w1_therm_family_converter w1_therm_families[] = {
+ {
+ .f = &w1_therm_family_DS18S20,
+ .convert = w1_DS18S20_convert_temp
+ },
+ {
+ .f = &w1_therm_family_DS1822,
+ .convert = w1_DS18B20_convert_temp
+ },
+ {
+ .f = &w1_therm_family_DS18B20,
+ .convert = w1_DS18B20_convert_temp
+ },
+};
+
+static inline int w1_DS18B20_convert_temp(u8 rom[9])
+{
+ int t = (rom[1] << 8) | rom[0];
+ t /= 16;
+ return t;
+}
+
+static inline int w1_DS18S20_convert_temp(u8 rom[9])
+{
+ int t, h;
+
+ if (!rom[7])
+ return 0;
+
+ if (rom[1] == 0)
+ t = ((s32)rom[0] >> 1)*1000;
+ else
+ t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
+
+ t -= 250;
+ h = 1000*((s32)rom[7] - (s32)rom[6]);
+ h /= (s32)rom[7];
+ t += h;
+
+ return t;
+}
+
+static inline int w1_convert_temp(u8 rom[9], u8 fid)
+{
+ int i;
+
+ for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
+ if (w1_therm_families[i].f->fid == fid)
+ return w1_therm_families[i].convert(rom);
+
+ return 0;
+}
+
+static int w1_therm_check_rom(u8 rom[9])
+{
+ int i;
+
+ for (i=0; i<sizeof(bad_roms)/9; ++i)
+ if (!memcmp(bad_roms[i], rom, 9))
+ return 1;
+
+ return 0;
+}
+
+static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, size_t count)
+{
+ struct w1_slave *sl = kobj_to_w1_slave(kobj);
+ struct w1_master *dev = sl->master;
+ u8 rom[9], crc, verdict;
+ int i, max_trying = 10;
+
+ atomic_inc(&sl->refcnt);
+ smp_mb__after_atomic_inc();
+ if (down_interruptible(&sl->master->mutex)) {
+ count = 0;
+ goto out_dec;
+ }
+
+ if (off > W1_SLAVE_DATA_SIZE) {
+ count = 0;
+ goto out;
+ }
+ if (off + count > W1_SLAVE_DATA_SIZE) {
+ count = 0;
+ goto out;
+ }
+
+ memset(buf, 0, count);
+ memset(rom, 0, sizeof(rom));
+
+ count = 0;
+ verdict = 0;
+ crc = 0;
+
+ while (max_trying--) {
+ if (!w1_reset_select_slave(sl)) {
+ int count = 0;
+ unsigned int tm = 750;
+
+ w1_write_8(dev, W1_CONVERT_TEMP);
+
+ while (tm) {
+ tm = msleep_interruptible(tm);
+ if (signal_pending(current))
+ flush_signals(current);
+ }
+
+ if (!w1_reset_select_slave(sl)) {
+
+ w1_write_8(dev, W1_READ_SCRATCHPAD);
+ if ((count = w1_read_block(dev, rom, 9)) != 9) {
+ dev_warn(&dev->dev, "w1_read_block() returned %d instead of 9.\n", count);
+ }
+
+ crc = w1_calc_crc8(rom, 8);
+
+ if (rom[8] == crc && rom[0])
+ verdict = 1;
+ }
+ }
+
+ if (!w1_therm_check_rom(rom))
+ break;
+ }
+
+ for (i = 0; i < 9; ++i)
+ count += sprintf(buf + count, "%02x ", rom[i]);
+ count += sprintf(buf + count, ": crc=%02x %s\n",
+ crc, (verdict) ? "YES" : "NO");
+ if (verdict)
+ memcpy(sl->rom, rom, sizeof(sl->rom));
+ else
+ dev_warn(&dev->dev, "18S20 doesn't respond to CONVERT_TEMP.\n");
+
+ for (i = 0; i < 9; ++i)
+ count += sprintf(buf + count, "%02x ", sl->rom[i]);
+
+ count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom, sl->family->fid));
+out:
+ up(&dev->mutex);
+out_dec:
+ smp_mb__before_atomic_inc();
+ atomic_dec(&sl->refcnt);
+
+ return count;
+}
+
+static int __init w1_therm_init(void)
+{
+ int err, i;
+
+ for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i) {
+ err = w1_register_family(w1_therm_families[i].f);
+ if (err)
+ w1_therm_families[i].broken = 1;
+ }
+
+ return 0;
+}
+
+static void __exit w1_therm_fini(void)
+{
+ int i;
+
+ for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
+ if (!w1_therm_families[i].broken)
+ w1_unregister_family(w1_therm_families[i].f);
+}
+
+module_init(w1_therm_init);
+module_exit(w1_therm_fini);