--- /dev/null
+From bd7d1508a83c544f2d52f668ebabe55c2ea207c5 Mon Sep 17 00:00:00 2001
+From: popcornmix <popcornmix@gmail.com>
+Date: Wed, 8 May 2013 11:46:50 +0100
+Subject: [PATCH 021/114] enabling the realtime clock 1-wire chip DS1307 and
+ 1-wire on GPIO4 (as a module)
+
+1-wire: Add support for configuring pin for w1-gpio kernel module
+See: https://github.com/raspberrypi/linux/pull/457
+
+Add bitbanging pullups, use them for w1-gpio
+
+Allows parasite power to work, uses module option pullup=1
+
+bcm2708: Ensure 1-wire pullup is disabled by default, and expose as module parameter
+
+Signed-off-by: Alex J Lennon <ajlennon@dynamicdevices.co.uk>
+
+w1-gpio: Add gpiopin module parameter and correctly free up gpio pull-up pin, if set
+
+Signed-off-by: Alex J Lennon <ajlennon@dynamicdevices.co.uk>
+---
+ arch/arm/mach-bcm2708/bcm2708.c | 29 ++++++++++++++++++++++
+ drivers/w1/masters/w1-gpio.c | 55 +++++++++++++++++++++++++++++++++++++----
+ drivers/w1/w1.h | 6 +++++
+ drivers/w1/w1_int.c | 14 +++++++++++
+ drivers/w1/w1_io.c | 18 +++++++++++---
+ 5 files changed, 114 insertions(+), 8 deletions(-)
+
+diff --git a/arch/arm/mach-bcm2708/bcm2708.c b/arch/arm/mach-bcm2708/bcm2708.c
+index 82f56fb..7dd89a7f 100644
+--- a/arch/arm/mach-bcm2708/bcm2708.c
++++ b/arch/arm/mach-bcm2708/bcm2708.c
+@@ -32,6 +32,7 @@
+ #include <linux/io.h>
+ #include <linux/module.h>
+ #include <linux/spi/spi.h>
++#include <linux/w1-gpio.h>
+
+ #include <linux/version.h>
+ #include <linux/clkdev.h>
+@@ -76,12 +77,19 @@
+ */
+ #define DMA_MASK_BITS_COMMON 32
+
++// use GPIO 4 for the one-wire GPIO pin, if enabled
++#define W1_GPIO 4
++// ensure one-wire GPIO pullup is disabled by default
++#define W1_PULLUP -1
++
+ /* command line parameters */
+ static unsigned boardrev, serial;
+ static unsigned uart_clock;
+ static unsigned disk_led_gpio = 16;
+ static unsigned disk_led_active_low = 1;
+ static unsigned reboot_part = 0;
++static unsigned w1_gpio_pin = W1_GPIO;
++static unsigned w1_gpio_pullup = W1_PULLUP;
+
+ static void __init bcm2708_init_led(void);
+
+@@ -258,6 +266,20 @@ static struct platform_device bcm2708_dmaman_device = {
+ .num_resources = ARRAY_SIZE(bcm2708_dmaman_resources),
+ };
+
++#if defined(CONFIG_W1_MASTER_GPIO) || defined(CONFIG_W1_MASTER_GPIO_MODULE)
++static struct w1_gpio_platform_data w1_gpio_pdata = {
++ .pin = W1_GPIO,
++ .ext_pullup_enable_pin = W1_PULLUP,
++ .is_open_drain = 0,
++};
++
++static struct platform_device w1_device = {
++ .name = "w1-gpio",
++ .id = -1,
++ .dev.platform_data = &w1_gpio_pdata,
++};
++#endif
++
+ static u64 fb_dmamask = DMA_BIT_MASK(DMA_MASK_BITS_COMMON);
+
+ static struct platform_device bcm2708_fb_device = {
+@@ -652,6 +674,11 @@ void __init bcm2708_init(void)
+ #ifdef CONFIG_BCM2708_GPIO
+ bcm_register_device(&bcm2708_gpio_device);
+ #endif
++#if defined(CONFIG_W1_MASTER_GPIO) || defined(CONFIG_W1_MASTER_GPIO_MODULE)
++ w1_gpio_pdata.pin = w1_gpio_pin;
++ w1_gpio_pdata.ext_pullup_enable_pin = w1_gpio_pullup;
++ platform_device_register(&w1_device);
++#endif
+ bcm_register_device(&bcm2708_systemtimer_device);
+ bcm_register_device(&bcm2708_fb_device);
+ bcm_register_device(&bcm2708_usb_device);
+@@ -853,3 +880,5 @@ module_param(uart_clock, uint, 0644);
+ module_param(disk_led_gpio, uint, 0644);
+ module_param(disk_led_active_low, uint, 0644);
+ module_param(reboot_part, uint, 0644);
++module_param(w1_gpio_pin, uint, 0644);
++module_param(w1_gpio_pullup, uint, 0644);
+diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c
+index 1d111e5..61be2cd 100644
+--- a/drivers/w1/masters/w1-gpio.c
++++ b/drivers/w1/masters/w1-gpio.c
+@@ -23,6 +23,15 @@
+ #include "../w1.h"
+ #include "../w1_int.h"
+
++static int w1_gpio_pullup = -1;
++static int w1_gpio_pullup_orig = -1;
++module_param_named(pullup, w1_gpio_pullup, int, 0);
++MODULE_PARM_DESC(pullup, "GPIO pin pullup number");
++static int w1_gpio_pin = -1;
++static int w1_gpio_pin_orig = -1;
++module_param_named(gpiopin, w1_gpio_pin, int, 0);
++MODULE_PARM_DESC(gpiopin, "GPIO pin number");
++
+ static u8 w1_gpio_set_pullup(void *data, int delay)
+ {
+ struct w1_gpio_platform_data *pdata = data;
+@@ -67,6 +76,16 @@ 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" },
+@@ -113,13 +132,15 @@ static int w1_gpio_probe_dt(struct platform_device *pdev)
+ static int w1_gpio_probe(struct platform_device *pdev)
+ {
+ struct w1_bus_master *master;
+- struct w1_gpio_platform_data *pdata;
++ struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
+ int err;
+
+- if (of_have_populated_dt()) {
+- err = w1_gpio_probe_dt(pdev);
+- if (err < 0)
+- return err;
++ if(pdata == NULL) {
++ if (of_have_populated_dt()) {
++ err = w1_gpio_probe_dt(pdev);
++ if (err < 0)
++ return err;
++ }
+ }
+
+ pdata = dev_get_platdata(&pdev->dev);
+@@ -136,6 +157,19 @@ static int w1_gpio_probe(struct platform_device *pdev)
+ return -ENOMEM;
+ }
+
++ w1_gpio_pin_orig = pdata->pin;
++ w1_gpio_pullup_orig = pdata->ext_pullup_enable_pin;
++
++ if(gpio_is_valid(w1_gpio_pin)) {
++ pdata->pin = w1_gpio_pin;
++ pdata->ext_pullup_enable_pin = -1;
++ }
++ if(gpio_is_valid(w1_gpio_pullup)) {
++ pdata->ext_pullup_enable_pin = w1_gpio_pullup;
++ }
++
++ dev_info(&pdev->dev, "gpio pin %d, gpio pullup pin %d\n", pdata->pin, pdata->ext_pullup_enable_pin);
++
+ err = devm_gpio_request(&pdev->dev, pdata->pin, "w1");
+ if (err) {
+ dev_err(&pdev->dev, "gpio_request (pin) failed\n");
+@@ -165,6 +199,14 @@ static int w1_gpio_probe(struct platform_device *pdev)
+ master->set_pullup = w1_gpio_set_pullup;
+ }
+
++ if (gpio_is_valid(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");
+@@ -195,6 +237,9 @@ static int w1_gpio_remove(struct platform_device *pdev)
+
+ w1_remove_master_device(master);
+
++ pdata->pin = w1_gpio_pin_orig;
++ pdata->ext_pullup_enable_pin = w1_gpio_pullup_orig;
++
+ return 0;
+ }
+
+diff --git a/drivers/w1/w1.h b/drivers/w1/w1.h
+index 56a49ba..881d728 100644
+--- a/drivers/w1/w1.h
++++ b/drivers/w1/w1.h
+@@ -171,6 +171,12 @@ 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);
++
+ void (*search)(void *, struct w1_master *,
+ u8, w1_slave_found_callback);
+ };
+diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
+index 47249a3..a4b4a8d 100644
+--- a/drivers/w1/w1_int.c
++++ b/drivers/w1/w1_int.c
+@@ -123,6 +123,20 @@ int w1_add_master_device(struct w1_bus_master *master)
+ return(-EINVAL);
+ }
+
++ /* 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 2820924..fd0550f 100644
+--- a/drivers/w1/w1_io.c
++++ b/drivers/w1/w1_io.c
+@@ -134,10 +134,22 @@ 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;
+ }
+ }
+--
+1.8.3.2
+
projects / 15.05 / openwrt.git / blobdiff