diff options
Diffstat (limited to 'drivers/w1/slaves/w1_ds2760.c')
| -rw-r--r-- | drivers/w1/slaves/w1_ds2760.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/drivers/w1/slaves/w1_ds2760.c b/drivers/w1/slaves/w1_ds2760.c new file mode 100644 index 00000000000..1f2b1a4d5fb --- /dev/null +++ b/drivers/w1/slaves/w1_ds2760.c @@ -0,0 +1,213 @@ +/* + * 1-Wire implementation for the ds2760 chip + * + * Copyright © 2004-2005, Szabolcs Gyurko <szabolcs.gyurko@tlt.hu> + * + * Use consistent with the GNU GPL is permitted, + * provided that this copyright notice is + * preserved in its entirety in all copies and derived works. + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/types.h> +#include <linux/platform_device.h> +#include <linux/mutex.h> +#include <linux/idr.h> + +#include "../w1.h" +#include "../w1_int.h" +#include "../w1_family.h" +#include "w1_ds2760.h" + +static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count, + int io) +{ + struct w1_slave *sl = container_of(dev, struct w1_slave, dev); + + if (!dev) + return 0; + + mutex_lock(&sl->master->mutex); + + if (addr > DS2760_DATA_SIZE || addr < 0) { + count = 0; + goto out; + } + if (addr + count > DS2760_DATA_SIZE) + count = DS2760_DATA_SIZE - addr; + + if (!w1_reset_select_slave(sl)) { + if (!io) { + w1_write_8(sl->master, W1_DS2760_READ_DATA); + w1_write_8(sl->master, addr); + count = w1_read_block(sl->master, buf, count); + } else { + w1_write_8(sl->master, W1_DS2760_WRITE_DATA); + w1_write_8(sl->master, addr); + w1_write_block(sl->master, buf, count); + /* XXX w1_write_block returns void, not n_written */ + } + } + +out: + mutex_unlock(&sl->master->mutex); + + return count; +} + +int w1_ds2760_read(struct device *dev, char *buf, int addr, size_t count) +{ + return w1_ds2760_io(dev, buf, addr, count, 0); +} + +int w1_ds2760_write(struct device *dev, char *buf, int addr, size_t count) +{ + return w1_ds2760_io(dev, buf, addr, count, 1); +} + +static ssize_t w1_ds2760_read_bin(struct kobject *kobj, struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + struct device *dev = container_of(kobj, struct device, kobj); + return w1_ds2760_read(dev, buf, off, count); +} + +static struct bin_attribute w1_ds2760_bin_attr = { + .attr = { + .name = "w1_slave", + .mode = S_IRUGO, + .owner = THIS_MODULE, + }, + .size = DS2760_DATA_SIZE, + .read = w1_ds2760_read_bin, +}; + +static DEFINE_IDR(bat_idr); +static DEFINE_MUTEX(bat_idr_lock); + +static int new_bat_id(void) +{ + int ret; + + while (1) { + int id; + + ret = idr_pre_get(&bat_idr, GFP_KERNEL); + if (ret == 0) + return -ENOMEM; + + mutex_lock(&bat_idr_lock); + ret = idr_get_new(&bat_idr, NULL, &id); + mutex_unlock(&bat_idr_lock); + + if (ret == 0) { + ret = id & MAX_ID_MASK; + break; + } else if (ret == -EAGAIN) { + continue; + } else { + break; + } + } + + return ret; +} + +static void release_bat_id(int id) +{ + mutex_lock(&bat_idr_lock); + idr_remove(&bat_idr, id); + mutex_unlock(&bat_idr_lock); + + return; +} + +static int w1_ds2760_add_slave(struct w1_slave *sl) +{ + int ret; + int id; + struct platform_device *pdev; + + id = new_bat_id(); + if (id < 0) { + ret = id; + goto noid; + } + + pdev = platform_device_alloc("ds2760-battery", id); + if (!pdev) { + ret = -ENOMEM; + goto pdev_alloc_failed; + } + pdev->dev.parent = &sl->dev; + + ret = platform_device_add(pdev); + if (ret) + goto pdev_add_failed; + + ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr); + if (ret) + goto bin_attr_failed; + + dev_set_drvdata(&sl->dev, pdev); + + goto success; + +bin_attr_failed: +pdev_add_failed: + platform_device_unregister(pdev); +pdev_alloc_failed: + release_bat_id(id); +noid: +success: + return ret; +} + +static void w1_ds2760_remove_slave(struct w1_slave *sl) +{ + struct platform_device *pdev = dev_get_drvdata(&sl->dev); + int id = pdev->id; + + platform_device_unregister(pdev); + release_bat_id(id); + sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr); + + return; +} + +static struct w1_family_ops w1_ds2760_fops = { + .add_slave = w1_ds2760_add_slave, + .remove_slave = w1_ds2760_remove_slave, +}; + +static struct w1_family w1_ds2760_family = { + .fid = W1_FAMILY_DS2760, + .fops = &w1_ds2760_fops, +}; + +static int __init w1_ds2760_init(void) +{ + printk(KERN_INFO "1-Wire driver for the DS2760 battery monitor " + " chip - (c) 2004-2005, Szabolcs Gyurko\n"); + idr_init(&bat_idr); + return w1_register_family(&w1_ds2760_family); +} + +static void __exit w1_ds2760_exit(void) +{ + w1_unregister_family(&w1_ds2760_family); + idr_destroy(&bat_idr); +} + +EXPORT_SYMBOL(w1_ds2760_read); +EXPORT_SYMBOL(w1_ds2760_write); + +module_init(w1_ds2760_init); +module_exit(w1_ds2760_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>"); +MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip"); |