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Date: Mon, 01 Nov 2010 12:35:59 +0000
From: Jonathan Cameron <jic23@....ac.uk>
To: Maciej Szmigiero <mhej@...pl>
CC: johnpol@....mipt.ru, linux-kernel@...r.kernel.org,
David Brownell <dbrownell@...rs.sourceforge.net>
Subject: Re: [W1] a driver for DS2405 chip
On 10/28/10 21:52, Maciej Szmigiero wrote:
> [W1] a driver for DS2405 chip
>
> This is a driver for DS2405 1-wire single-channel addressable switch / PIO.
> DS2405 can also work as single-channel binary remote sensor.
Perhaps handle this as a gpio chip? (be it a fairly limited one)
To my mind it would make it more generally useful...
>
> Signed-off-by: Maciej Szmigiero <mhej@...pl>
>
> --- a/drivers/w1/w1_family.h 2009-06-10 05:05:27.000000000 +0200
> +++ b/drivers/w1/w1_family.h 2009-12-13 22:23:32.994770399 +0100
> @@ -28,6 +28,7 @@
>
> #define W1_FAMILY_DEFAULT 0
> #define W1_FAMILY_SMEM_01 0x01
> +#define W1_FAMILY_DS2405 0x05
> #define W1_FAMILY_SMEM_81 0x81
> #define W1_THERM_DS18S20 0x10
> #define W1_THERM_DS1822 0x22
> --- a/drivers/w1/w1_io.c 2009-06-10 05:05:27.000000000 +0200
> +++ b/drivers/w1/w1_io.c 2009-12-15 22:32:48.362801835 +0100
> @@ -210,6 +210,7 @@
> return retval;
> }
> }
> +EXPORT_SYMBOL_GPL(w1_triplet);
>
> /**
> * Reads 8 bits.
> --- /dev/null 2010-10-28 22:18:50.899999998 +0200
> +++ b/drivers/w1/slaves/w1_ds2405.c 2010-10-28 22:42:13.000000000 +0200
> @@ -0,0 +1,251 @@
> +/*
> + * w1_ds2405.c
> + *
> + * Copyright (c) 2009 Maciej Szmigiero <mhej@...pl>
> + * Based on w1_therm.c copyright (c) 2004 Evgeniy Polyakov <johnpol@....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 <linux/types.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/sched.h>
> +#include <linux/device.h>
> +#include <linux/types.h>
> +#include <linux/delay.h>
> +
> +#include "../w1.h"
> +#include "../w1_int.h"
> +#include "../w1_family.h"
> +
> +static int w1_ds2405_select(struct w1_slave *sl, int only_active)
> +{
> + struct w1_master *dev = sl->master;
> + int ret;
> +
> + if (w1_reset_bus(dev) != 0)
> + return 0;
> +
> + /* We cannot use normal Match ROM command */
> + /* since doing so would toggle PIO state */
> + w1_write_8(dev, only_active ? W1_ALARM_SEARCH : W1_SEARCH);
> +
> + do {
> + u64 dev_addr = cpu_to_le64(((u64)sl->reg_num.crc<<(8+48))
> + | ((u64)sl->reg_num.id<<8)
> + | sl->reg_num.family);
> + u8 bit_ctr;
> +
> + for (bit_ctr = 0; bit_ctr < 64; bit_ctr++) {
> + int bit2send = !!(dev_addr & 1LL<<bit_ctr);
> + ret = w1_triplet(dev, bit2send);
> +
> + if ((ret & 3) == 3) /* no devices found */
> + return 0;
> +
> + if ((!!(ret & 4)) != bit2send)
> + /* wrong direction taken - no such device */
> + return 0;
> + }
> + } while (0);
> +
> + return 1;
> +}
> +
> +static int w1_ds2405_read_pio(struct w1_slave *sl)
> +{
> + if (w1_ds2405_select(sl, 1))
> + return 0; /* "active" means PIO is low */
> +
> + if (w1_ds2405_select(sl, 0))
> + return 1;
> + else
> + return -ENODEV;
> +}
> +
> +static ssize_t w1_ds2405_read_sensed_file(struct device *device,
> + struct device_attribute *attr, char *buf)
> +{
> + struct w1_slave *sl = dev_to_w1_slave(device);
> + struct w1_master *dev = sl->master;
> +
> + int ret;
> + ssize_t f_retval;
> + u8 state;
> +
> + ret = mutex_lock_interruptible(&dev->mutex);
> + if (ret)
> + return ret;
> +
> + if (!w1_ds2405_select(sl, 0)) {
> + f_retval = -ENODEV;
> + goto out_unlock;
> + }
> +
> + state = w1_read_8(dev);
> +
> + f_retval = snprintf(buf, PAGE_SIZE, "%u\n", !!(state));
> +
> +out_unlock:
> + w1_reset_bus(dev);
> + mutex_unlock(&dev->mutex);
> +
> + return f_retval;
> +}
> +
> +static ssize_t w1_ds2405_read_pio_file(struct device *device,
> + struct device_attribute *attr, char *buf)
> +{
> + struct w1_slave *sl = dev_to_w1_slave(device);
> + struct w1_master *dev = sl->master;
> +
> + int ret;
> + ssize_t f_retval;
> +
> + ret = mutex_lock_interruptible(&dev->mutex);
> + if (ret)
> + return ret;
> +
> + ret = w1_ds2405_read_pio(sl);
> + if (ret < 0) {
> + f_retval = ret;
> + goto out_unlock;
> + }
> +
> + f_retval = snprintf(buf, PAGE_SIZE, "%d\n", ret);
> +
> +out_unlock:
> + w1_reset_bus(dev);
> + mutex_unlock(&dev->mutex);
> +
> + return f_retval;
> +}
> +
> +static ssize_t w1_ds2405_write_pio_file(struct device *device,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct w1_slave *sl = dev_to_w1_slave(device);
> + struct w1_master *dev = sl->master;
> +
> + int ret, current_pio;
> + unsigned int val;
> + ssize_t f_retval;
> +
> + if (count < 1)
> + return -EINVAL;
> +
> + /* fill_write_buffer() in fs/sysfs/file.c */
> + /* keeps the buffer null-terminated */
> + if (sscanf(buf, " %u%n", &val, &ret) < 1)
> + return -EINVAL;
> +
> + if ((val != 0) && (val != 1))
> + return -EINVAL;
> +
> + f_retval = ret;
> +
> + ret = mutex_lock_interruptible(&dev->mutex);
> + if (ret)
> + return ret;
> +
> + current_pio = w1_ds2405_read_pio(sl);
> + if (current_pio < 0) {
> + f_retval = current_pio;
> + goto out_unlock;
> + }
> +
> + if (current_pio == val)
> + goto out_unlock;
> +
> + if (w1_reset_bus(dev) != 0) {
> + f_retval = -ENODEV;
> + goto out_unlock;
> + }
> +
> + do {
> + u64 dev_addr = cpu_to_le64(((u64)sl->reg_num.crc<<(8+48))
> + | ((u64)sl->reg_num.id<<8) | sl->reg_num.family);
> +
> + w1_write_8(dev, W1_MATCH_ROM);
> + w1_write_block(dev, (u8 *)&dev_addr, 8);
> + } while (0);
> +
> +out_unlock:
> + w1_reset_bus(dev);
> + mutex_unlock(&dev->mutex);
> +
> + return f_retval;
> +}
> +
> +static DEVICE_ATTR(sensed, S_IRUSR | S_IRGRP, w1_ds2405_read_sensed_file, NULL);
> +static DEVICE_ATTR(PIO, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP,
> + w1_ds2405_read_pio_file, w1_ds2405_write_pio_file);
> +
> +static int w1_ds2405_add_slave(struct w1_slave *sl)
> +{
> + int err;
> +
> + err = device_create_file(&sl->dev, &dev_attr_sensed);
> + if (err)
> + return err;
> +
> + err = device_create_file(&sl->dev, &dev_attr_PIO);
> + if (err) {
> + device_remove_file(&sl->dev, &dev_attr_sensed);
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +static void w1_ds2405_remove_slave(struct w1_slave *sl)
> +{
> + device_remove_file(&sl->dev, &dev_attr_sensed);
> + device_remove_file(&sl->dev, &dev_attr_PIO);
> +}
> +
> +
> +static struct w1_family_ops w1_ds2405_fops = {
> + .add_slave = w1_ds2405_add_slave,
> + .remove_slave = w1_ds2405_remove_slave,
> +};
> +
> +
> +static struct w1_family w1_family_ds2405 = {
> + .fid = W1_FAMILY_DS2405,
> + .fops = &w1_ds2405_fops,
> +};
> +
> +static int __init w1_ds2405_init(void)
> +{
> + return w1_register_family(&w1_family_ds2405);
> +}
> +
> +static void __exit w1_ds2405_fini(void)
> +{
> +
> + w1_unregister_family(&w1_family_ds2405);
> +}
> +
> +module_init(w1_ds2405_init);
> +module_exit(w1_ds2405_fini);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Maciej Szmigiero <mhej@...pl>");
> +MODULE_DESCRIPTION("Driver for 1-wire Dallas DS2405 PIO");
> --- a/drivers/w1/slaves/Makefile 2010-08-02 00:11:14.000000000 +0200
> +++ b/drivers/w1/slaves/Makefile 2010-10-28 22:39:13.000000000 +0200
> @@ -4,6 +4,7 @@
>
> obj-$(CONFIG_W1_SLAVE_THERM) += w1_therm.o
> obj-$(CONFIG_W1_SLAVE_SMEM) += w1_smem.o
> +obj-$(CONFIG_W1_SLAVE_DS2405) += w1_ds2405.o
> obj-$(CONFIG_W1_SLAVE_DS2431) += w1_ds2431.o
> obj-$(CONFIG_W1_SLAVE_DS2433) += w1_ds2433.o
> obj-$(CONFIG_W1_SLAVE_DS2760) += w1_ds2760.o
> --- a/drivers/w1/slaves/Kconfig 2010-08-02 00:11:14.000000000 +0200
> +++ b/drivers/w1/slaves/Kconfig 2010-10-28 22:37:55.000000000 +0200
> @@ -16,6 +16,14 @@
> Say Y here if you want to connect 1-wire
> simple 64bit memory rom(ds2401/ds2411/ds1990*) to your wire.
>
> +config W1_SLAVE_DS2405
> + tristate "DS2405 Addressable Switch / PIO"
> + help
> + Say Y here if you want to build driver for 1-wire
> + single-channel addressable switch / PIO.
> + This device can also work as single-channel
> + binary remote sensor.
> +
> config W1_SLAVE_DS2431
> tristate "1kb EEPROM family support (DS2431)"
> help
>
>
> --
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