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Diffstat (limited to 'target/linux/brcm2708/patches-3.10/0055-Add-bitbanging-pullups-use-them-for-w1-gpio.patch')
-rw-r--r--target/linux/brcm2708/patches-3.10/0055-Add-bitbanging-pullups-use-them-for-w1-gpio.patch130
1 files changed, 130 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-3.10/0055-Add-bitbanging-pullups-use-them-for-w1-gpio.patch b/target/linux/brcm2708/patches-3.10/0055-Add-bitbanging-pullups-use-them-for-w1-gpio.patch
new file mode 100644
index 0000000000..f71bc9ffe0
--- /dev/null
+++ b/target/linux/brcm2708/patches-3.10/0055-Add-bitbanging-pullups-use-them-for-w1-gpio.patch
@@ -0,0 +1,130 @@
+From 28ca85a46bbdae4152b48a669872ac205d053856 Mon Sep 17 00:00:00 2001
+From: popcornmix <popcornmix@gmail.com>
+Date: Wed, 1 May 2013 21:14:28 +0100
+Subject: [PATCH 055/174] 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(-)
+
+--- 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
+ 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");
+--- 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.
+ */
+--- a/drivers/w1/w1_int.c
++++ b/drivers/w1/w1_int.c
+@@ -117,19 +117,21 @@ int w1_add_master_device(struct w1_bus_m
+ 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). */
+--- a/drivers/w1/w1_io.c
++++ b/drivers/w1/w1_io.c
+@@ -127,10 +127,22 @@ static void w1_pre_write(struct w1_maste
+ 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;
+ }
+ }