+++ /dev/null
-From 0a2fa5a85c2ed9599acb2215f24e06db0379a133 Mon Sep 17 00:00:00 2001
-From: popcornmix <popcornmix@gmail.com>
-Date: Wed, 1 May 2013 21:14:28 +0100
-Subject: [PATCH 055/196] Add bitbanging pullups, use them for w1-gpio
-
-Allows parasite power to work, uses module option pullup=1
----
- drivers/w1/masters/w1-gpio.c | 20 ++++++++++++++++++++
- drivers/w1/w1.h | 6 ++++++
- drivers/w1/w1_int.c | 16 +++++++++-------
- drivers/w1/w1_io.c | 18 +++++++++++++++---
- 4 files changed, 50 insertions(+), 10 deletions(-)
-
-diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c
-index 46d9701..f615f80 100644
---- a/drivers/w1/masters/w1-gpio.c
-+++ b/drivers/w1/masters/w1-gpio.c
-@@ -23,6 +23,9 @@
- #include "../w1.h"
- #include "../w1_int.h"
-
-+static int w1_gpio_pullup = 0;
-+module_param_named(pullup, w1_gpio_pullup, int, 0);
-+
- static void w1_gpio_write_bit_dir(void *data, u8 bit)
- {
- struct w1_gpio_platform_data *pdata = data;
-@@ -47,6 +50,16 @@ static u8 w1_gpio_read_bit(void *data)
- return gpio_get_value(pdata->pin) ? 1 : 0;
- }
-
-+static void w1_gpio_bitbang_pullup(void *data, u8 on)
-+{
-+ struct w1_gpio_platform_data *pdata = data;
-+
-+ if (on)
-+ gpio_direction_output(pdata->pin, 1);
-+ else
-+ gpio_direction_input(pdata->pin);
-+}
-+
- #if defined(CONFIG_OF)
- static struct of_device_id w1_gpio_dt_ids[] = {
- { .compatible = "w1-gpio" },
-@@ -133,6 +146,13 @@ static int w1_gpio_probe(struct platform_device *pdev)
- master->write_bit = w1_gpio_write_bit_dir;
- }
-
-+ if (w1_gpio_pullup)
-+ if (pdata->is_open_drain)
-+ printk(KERN_ERR "w1-gpio 'pullup' option "
-+ "doesn't work with open drain GPIO\n");
-+ else
-+ master->bitbang_pullup = w1_gpio_bitbang_pullup;
-+
- err = w1_add_master_device(master);
- if (err) {
- dev_err(&pdev->dev, "w1_add_master device failed\n");
-diff --git a/drivers/w1/w1.h b/drivers/w1/w1.h
-index 45908e5..0ba75f6 100644
---- a/drivers/w1/w1.h
-+++ b/drivers/w1/w1.h
-@@ -148,6 +148,12 @@ struct w1_bus_master
- */
- u8 (*set_pullup)(void *, int);
-
-+ /**
-+ * Turns the pullup on/off in bitbanging mode, takes an on/off argument.
-+ * @return -1=Error, 0=completed
-+ */
-+ void (*bitbang_pullup) (void *, u8);
-+
- /** Really nice hardware can handles the different types of ROM search
- * w1_master* is passed to the slave found callback.
- */
-diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
-index 5a98649..a4d69b6 100644
---- a/drivers/w1/w1_int.c
-+++ b/drivers/w1/w1_int.c
-@@ -117,19 +117,21 @@ int w1_add_master_device(struct w1_bus_master *master)
- printk(KERN_ERR "w1_add_master_device: invalid function set\n");
- return(-EINVAL);
- }
-- /* While it would be electrically possible to make a device that
-- * generated a strong pullup in bit bang mode, only hardware that
-- * controls 1-wire time frames are even expected to support a strong
-- * pullup. w1_io.c would need to support calling set_pullup before
-- * the last write_bit operation of a w1_write_8 which it currently
-- * doesn't.
-- */
-+
-+ /* bitbanging hardware uses bitbang_pullup, other hardware uses set_pullup
-+ * and takes care of timing itself */
- if (!master->write_byte && !master->touch_bit && master->set_pullup) {
- printk(KERN_ERR "w1_add_master_device: set_pullup requires "
- "write_byte or touch_bit, disabling\n");
- master->set_pullup = NULL;
- }
-
-+ if (master->set_pullup && master->bitbang_pullup) {
-+ printk(KERN_ERR "w1_add_master_device: set_pullup should not "
-+ "be set when bitbang_pullup is used, disabling\n");
-+ master->set_pullup = NULL;
-+ }
-+
- /* Lock until the device is added (or not) to w1_masters. */
- mutex_lock(&w1_mlock);
- /* Search for the first available id (starting at 1). */
-diff --git a/drivers/w1/w1_io.c b/drivers/w1/w1_io.c
-index e10acc2..667fdd5 100644
---- a/drivers/w1/w1_io.c
-+++ b/drivers/w1/w1_io.c
-@@ -127,10 +127,22 @@ static void w1_pre_write(struct w1_master *dev)
- static void w1_post_write(struct w1_master *dev)
- {
- if (dev->pullup_duration) {
-- if (dev->enable_pullup && dev->bus_master->set_pullup)
-- dev->bus_master->set_pullup(dev->bus_master->data, 0);
-- else
-+ if (dev->enable_pullup) {
-+ if (dev->bus_master->set_pullup) {
-+ dev->bus_master->set_pullup(dev->
-+ bus_master->data,
-+ 0);
-+ } else if (dev->bus_master->bitbang_pullup) {
-+ dev->bus_master->
-+ bitbang_pullup(dev->bus_master->data, 1);
-+ msleep(dev->pullup_duration);
-+ dev->bus_master->
-+ bitbang_pullup(dev->bus_master->data, 0);
-+ }
-+ } else {
- msleep(dev->pullup_duration);
-+ }
-+
- dev->pullup_duration = 0;
- }
- }
---
-1.9.1
-
projects / openwrt.git / blobdiff