bb39b8d99a
Update our copies of the brcm2708 patches to the latest rpi-3.10-y rebased against linux-3.10.y stable (3.10.32). This should hopefully make it easier for us in the future to leverage the raspberry/rpi-* branches. Signed-off-by: Florian Fainelli <florian@openwrt.org> SVN-Revision: 39770
131 lines
4.1 KiB
Diff
131 lines
4.1 KiB
Diff
From 28ca85a46bbdae4152b48a669872ac205d053856 Mon Sep 17 00:00:00 2001
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From: popcornmix <popcornmix@gmail.com>
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Date: Wed, 1 May 2013 21:14:28 +0100
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Subject: [PATCH 055/174] Add bitbanging pullups, use them for w1-gpio
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Allows parasite power to work, uses module option pullup=1
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---
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drivers/w1/masters/w1-gpio.c | 20 ++++++++++++++++++++
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drivers/w1/w1.h | 6 ++++++
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drivers/w1/w1_int.c | 16 +++++++++-------
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drivers/w1/w1_io.c | 18 +++++++++++++++---
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4 files changed, 50 insertions(+), 10 deletions(-)
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--- a/drivers/w1/masters/w1-gpio.c
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+++ b/drivers/w1/masters/w1-gpio.c
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@@ -23,6 +23,9 @@
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#include "../w1.h"
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#include "../w1_int.h"
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+static int w1_gpio_pullup = 0;
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+module_param_named(pullup, w1_gpio_pullup, int, 0);
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+
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static void w1_gpio_write_bit_dir(void *data, u8 bit)
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{
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struct w1_gpio_platform_data *pdata = data;
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@@ -47,6 +50,16 @@ static u8 w1_gpio_read_bit(void *data)
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return gpio_get_value(pdata->pin) ? 1 : 0;
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}
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+static void w1_gpio_bitbang_pullup(void *data, u8 on)
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+{
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+ struct w1_gpio_platform_data *pdata = data;
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+
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+ if (on)
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+ gpio_direction_output(pdata->pin, 1);
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+ else
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+ gpio_direction_input(pdata->pin);
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+}
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+
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#if defined(CONFIG_OF)
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static struct of_device_id w1_gpio_dt_ids[] = {
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{ .compatible = "w1-gpio" },
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@@ -133,6 +146,13 @@ static int w1_gpio_probe(struct platform
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master->write_bit = w1_gpio_write_bit_dir;
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}
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+ if (w1_gpio_pullup)
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+ if (pdata->is_open_drain)
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+ printk(KERN_ERR "w1-gpio 'pullup' option "
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+ "doesn't work with open drain GPIO\n");
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+ else
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+ master->bitbang_pullup = w1_gpio_bitbang_pullup;
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+
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err = w1_add_master_device(master);
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if (err) {
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dev_err(&pdev->dev, "w1_add_master device failed\n");
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--- a/drivers/w1/w1.h
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+++ b/drivers/w1/w1.h
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@@ -148,6 +148,12 @@ struct w1_bus_master
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*/
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u8 (*set_pullup)(void *, int);
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+ /**
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+ * Turns the pullup on/off in bitbanging mode, takes an on/off argument.
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+ * @return -1=Error, 0=completed
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+ */
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+ void (*bitbang_pullup) (void *, u8);
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+
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/** Really nice hardware can handles the different types of ROM search
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* w1_master* is passed to the slave found callback.
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*/
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--- a/drivers/w1/w1_int.c
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+++ b/drivers/w1/w1_int.c
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@@ -117,19 +117,21 @@ int w1_add_master_device(struct w1_bus_m
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printk(KERN_ERR "w1_add_master_device: invalid function set\n");
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return(-EINVAL);
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}
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- /* While it would be electrically possible to make a device that
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- * generated a strong pullup in bit bang mode, only hardware that
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- * controls 1-wire time frames are even expected to support a strong
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- * pullup. w1_io.c would need to support calling set_pullup before
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- * the last write_bit operation of a w1_write_8 which it currently
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- * doesn't.
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- */
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+
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+ /* bitbanging hardware uses bitbang_pullup, other hardware uses set_pullup
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+ * and takes care of timing itself */
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if (!master->write_byte && !master->touch_bit && master->set_pullup) {
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printk(KERN_ERR "w1_add_master_device: set_pullup requires "
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"write_byte or touch_bit, disabling\n");
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master->set_pullup = NULL;
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}
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+ if (master->set_pullup && master->bitbang_pullup) {
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+ printk(KERN_ERR "w1_add_master_device: set_pullup should not "
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+ "be set when bitbang_pullup is used, disabling\n");
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+ master->set_pullup = NULL;
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+ }
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+
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/* Lock until the device is added (or not) to w1_masters. */
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mutex_lock(&w1_mlock);
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/* Search for the first available id (starting at 1). */
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--- a/drivers/w1/w1_io.c
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+++ b/drivers/w1/w1_io.c
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@@ -127,10 +127,22 @@ static void w1_pre_write(struct w1_maste
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static void w1_post_write(struct w1_master *dev)
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{
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if (dev->pullup_duration) {
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- if (dev->enable_pullup && dev->bus_master->set_pullup)
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- dev->bus_master->set_pullup(dev->bus_master->data, 0);
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- else
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+ if (dev->enable_pullup) {
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+ if (dev->bus_master->set_pullup) {
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+ dev->bus_master->set_pullup(dev->
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+ bus_master->data,
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+ 0);
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+ } else if (dev->bus_master->bitbang_pullup) {
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+ dev->bus_master->
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+ bitbang_pullup(dev->bus_master->data, 1);
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msleep(dev->pullup_duration);
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+ dev->bus_master->
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+ bitbang_pullup(dev->bus_master->data, 0);
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+ }
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+ } else {
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+ msleep(dev->pullup_duration);
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+ }
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+
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dev->pullup_duration = 0;
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}
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}
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