178 lines
6 KiB
Diff
Executable file
178 lines
6 KiB
Diff
Executable file
From 8ceb69e8548f27305e37866ec3b81a79e1402b1a Mon Sep 17 00:00:00 2001
|
|
From: Phil Elwell <phil@raspberrypi.org>
|
|
Date: Wed, 4 Feb 2015 12:59:36 +0000
|
|
Subject: [PATCH 103/114] w1-gpio: Sort out the pullup/parasitic power tangle
|
|
|
|
---
|
|
arch/arm/boot/dts/w1-gpio-overlay.dts | 4 +++-
|
|
arch/arm/boot/dts/w1-gpio-pullup-overlay.dts | 6 +++--
|
|
drivers/w1/masters/w1-gpio.c | 36 ++++++++++++++++++----------
|
|
include/linux/w1-gpio.h | 1 +
|
|
4 files changed, 32 insertions(+), 15 deletions(-)
|
|
|
|
diff --git a/arch/arm/boot/dts/w1-gpio-overlay.dts b/arch/arm/boot/dts/w1-gpio-overlay.dts
|
|
index b2c5ee2..29a3b48 100644
|
|
--- a/arch/arm/boot/dts/w1-gpio-overlay.dts
|
|
+++ b/arch/arm/boot/dts/w1-gpio-overlay.dts
|
|
@@ -1,4 +1,4 @@
|
|
-// Definitions for lirc-rpi module
|
|
+// Definitions for w1-gpio module (without external pullup)
|
|
/dts-v1/;
|
|
/plugin/;
|
|
|
|
@@ -14,6 +14,7 @@
|
|
pinctrl-names = "default";
|
|
pinctrl-0 = <&w1_pins>;
|
|
gpios = <&gpio 4 0>;
|
|
+ rpi,parasitic-power = <0>;
|
|
status = "okay";
|
|
};
|
|
};
|
|
@@ -33,5 +34,6 @@
|
|
__overrides__ {
|
|
gpiopin = <&w1>,"gpios:4",
|
|
<&w1_pins>,"brcm,pins:0";
|
|
+ pullup = <&w1>,"rpi,parasitic-power:0";
|
|
};
|
|
};
|
|
diff --git a/arch/arm/boot/dts/w1-gpio-pullup-overlay.dts b/arch/arm/boot/dts/w1-gpio-pullup-overlay.dts
|
|
index b3e97c2..66a98f6 100644
|
|
--- a/arch/arm/boot/dts/w1-gpio-pullup-overlay.dts
|
|
+++ b/arch/arm/boot/dts/w1-gpio-pullup-overlay.dts
|
|
@@ -1,4 +1,4 @@
|
|
-// Definitions for lirc-rpi module
|
|
+// Definitions for w1-gpio module (with external pullup)
|
|
/dts-v1/;
|
|
/plugin/;
|
|
|
|
@@ -14,6 +14,7 @@
|
|
pinctrl-names = "default";
|
|
pinctrl-0 = <&w1_pins>;
|
|
gpios = <&gpio 4 0>, <&gpio 5 1>;
|
|
+ rpi,parasitic-power = <0>;
|
|
status = "okay";
|
|
};
|
|
};
|
|
@@ -33,7 +34,8 @@
|
|
__overrides__ {
|
|
gpiopin = <&w1>,"gpios:4",
|
|
<&w1_pins>,"brcm,pins:0";
|
|
- pullup = <&w1>,"gpios:16",
|
|
+ extpullup = <&w1>,"gpios:16",
|
|
<&w1_pins>,"brcm,pins:4";
|
|
+ pullup = <&w1>,"rpi,parasitic-power:0";
|
|
};
|
|
};
|
|
diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c
|
|
index 61be2cd..54c0313 100644
|
|
--- a/drivers/w1/masters/w1-gpio.c
|
|
+++ b/drivers/w1/masters/w1-gpio.c
|
|
@@ -23,10 +23,14 @@
|
|
#include "../w1.h"
|
|
#include "../w1_int.h"
|
|
|
|
-static int w1_gpio_pullup = -1;
|
|
-static int w1_gpio_pullup_orig = -1;
|
|
+static int w1_gpio_pullup = 0;
|
|
+static int w1_gpio_pullup_orig = 0;
|
|
module_param_named(pullup, w1_gpio_pullup, int, 0);
|
|
-MODULE_PARM_DESC(pullup, "GPIO pin pullup number");
|
|
+MODULE_PARM_DESC(pullup, "Enable parasitic power (power on data) mode");
|
|
+static int w1_gpio_pullup_pin = -1;
|
|
+static int w1_gpio_pullup_pin_orig = -1;
|
|
+module_param_named(extpullup, w1_gpio_pullup_pin, int, 0);
|
|
+MODULE_PARM_DESC(extpullup, "GPIO external pullup pin number");
|
|
static int w1_gpio_pin = -1;
|
|
static int w1_gpio_pin_orig = -1;
|
|
module_param_named(gpiopin, w1_gpio_pin, int, 0);
|
|
@@ -99,6 +103,7 @@ static int w1_gpio_probe_dt(struct platform_device *pdev)
|
|
struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
|
|
struct device_node *np = pdev->dev.of_node;
|
|
int gpio;
|
|
+ u32 value;
|
|
|
|
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
|
|
if (!pdata)
|
|
@@ -107,6 +112,9 @@ static int w1_gpio_probe_dt(struct platform_device *pdev)
|
|
if (of_get_property(np, "linux,open-drain", NULL))
|
|
pdata->is_open_drain = 1;
|
|
|
|
+ if (of_property_read_u32(np, "rpi,parasitic-power", &value) == 0)
|
|
+ pdata->parasitic_power = (value != 0);
|
|
+
|
|
gpio = of_get_gpio(np, 0);
|
|
if (gpio < 0) {
|
|
if (gpio != -EPROBE_DEFER)
|
|
@@ -122,7 +130,7 @@ static int w1_gpio_probe_dt(struct platform_device *pdev)
|
|
if (gpio == -EPROBE_DEFER)
|
|
return gpio;
|
|
/* ignore other errors as the pullup gpio is optional */
|
|
- pdata->ext_pullup_enable_pin = gpio;
|
|
+ pdata->ext_pullup_enable_pin = (gpio >= 0) ? gpio : -1;
|
|
|
|
pdev->dev.platform_data = pdata;
|
|
|
|
@@ -158,17 +166,20 @@ static int w1_gpio_probe(struct platform_device *pdev)
|
|
}
|
|
|
|
w1_gpio_pin_orig = pdata->pin;
|
|
- w1_gpio_pullup_orig = pdata->ext_pullup_enable_pin;
|
|
+ w1_gpio_pullup_pin_orig = pdata->ext_pullup_enable_pin;
|
|
+ w1_gpio_pullup_orig = pdata->parasitic_power;
|
|
|
|
if(gpio_is_valid(w1_gpio_pin)) {
|
|
pdata->pin = w1_gpio_pin;
|
|
pdata->ext_pullup_enable_pin = -1;
|
|
+ pdata->parasitic_power = -1;
|
|
}
|
|
- if(gpio_is_valid(w1_gpio_pullup)) {
|
|
- pdata->ext_pullup_enable_pin = w1_gpio_pullup;
|
|
+ pdata->parasitic_power |= w1_gpio_pullup;
|
|
+ if(gpio_is_valid(w1_gpio_pullup_pin)) {
|
|
+ pdata->ext_pullup_enable_pin = w1_gpio_pullup_pin;
|
|
}
|
|
|
|
- dev_info(&pdev->dev, "gpio pin %d, gpio pullup pin %d\n", pdata->pin, pdata->ext_pullup_enable_pin);
|
|
+ dev_info(&pdev->dev, "gpio pin %d, external pullup pin %d, parasitic power %d\n", pdata->pin, pdata->ext_pullup_enable_pin, pdata->parasitic_power);
|
|
|
|
err = devm_gpio_request(&pdev->dev, pdata->pin, "w1");
|
|
if (err) {
|
|
@@ -199,10 +210,10 @@ 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->parasitic_power) {
|
|
if (pdata->is_open_drain)
|
|
- printk(KERN_ERR "w1-gpio 'pullup' option "
|
|
- "doesn't work with open drain GPIO\n");
|
|
+ printk(KERN_ERR "w1-gpio 'pullup'(parasitic power) "
|
|
+ "option doesn't work with open drain GPIO\n");
|
|
else
|
|
master->bitbang_pullup = w1_gpio_bitbang_pullup;
|
|
}
|
|
@@ -238,7 +249,8 @@ 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;
|
|
+ pdata->ext_pullup_enable_pin = w1_gpio_pullup_pin_orig;
|
|
+ pdata->parasitic_power = w1_gpio_pullup_orig;
|
|
|
|
return 0;
|
|
}
|
|
diff --git a/include/linux/w1-gpio.h b/include/linux/w1-gpio.h
|
|
index d58594a..feae942 100644
|
|
--- a/include/linux/w1-gpio.h
|
|
+++ b/include/linux/w1-gpio.h
|
|
@@ -18,6 +18,7 @@
|
|
struct w1_gpio_platform_data {
|
|
unsigned int pin;
|
|
unsigned int is_open_drain:1;
|
|
+ unsigned int parasitic_power:1;
|
|
void (*enable_external_pullup)(int enable);
|
|
unsigned int ext_pullup_enable_pin;
|
|
unsigned int pullup_duration;
|
|
--
|
|
1.8.3.2
|
|
|