As usual, this patches were taken (and rebased) from https://github.com/raspberrypi/linux/commits/rpi-4.1.y Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> SVN-Revision: 47258
		
			
				
	
	
		
			387 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			387 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
From ec1be1680332a4676db86178ce9f24917aeeca67 Mon Sep 17 00:00:00 2001
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						|
From: popcornmix <popcornmix@gmail.com>
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Date: Wed, 8 May 2013 11:46:50 +0100
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Subject: [PATCH 031/203] enabling the realtime clock 1-wire chip DS1307 and
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 1-wire on GPIO4 (as a module)
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1-wire: Add support for configuring pin for w1-gpio kernel module
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See: https://github.com/raspberrypi/linux/pull/457
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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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bcm2708: Ensure 1-wire pullup is disabled by default, and expose as module parameter
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Signed-off-by: Alex J Lennon <ajlennon@dynamicdevices.co.uk>
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w1-gpio: Add gpiopin module parameter and correctly free up gpio pull-up pin, if set
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 | 
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Signed-off-by: Alex J Lennon <ajlennon@dynamicdevices.co.uk>
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w1-gpio: Sort out the pullup/parasitic power tangle
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---
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						|
 arch/arm/mach-bcm2708/bcm2708.c | 29 +++++++++++++++++
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 arch/arm/mach-bcm2709/bcm2709.c | 29 +++++++++++++++++
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 drivers/w1/masters/w1-gpio.c    | 69 +++++++++++++++++++++++++++++++++++++----
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 drivers/w1/w1.h                 |  6 ++++
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 drivers/w1/w1_int.c             | 14 +++++++++
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 drivers/w1/w1_io.c              | 18 +++++++++--
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 include/linux/w1-gpio.h         |  1 +
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 7 files changed, 157 insertions(+), 9 deletions(-)
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--- a/arch/arm/mach-bcm2708/bcm2708.c
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+++ b/arch/arm/mach-bcm2708/bcm2708.c
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@@ -36,6 +36,7 @@
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 #include <linux/of_platform.h>
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 #include <linux/spi/spi.h>
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 #include <linux/gpio/machine.h>
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+#include <linux/w1-gpio.h>
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						|
 
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 #include <linux/version.h>
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 #include <linux/clkdev.h>
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@@ -77,12 +78,19 @@
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  */
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 #define DMA_MASK_BITS_COMMON 32
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						|
 
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+// use GPIO 4 for the one-wire GPIO pin, if enabled
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+#define W1_GPIO 4
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+// ensure one-wire GPIO pullup is disabled by default
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+#define W1_PULLUP -1
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+
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 /* command line parameters */
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 static unsigned boardrev, serial;
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 static unsigned uart_clock = UART0_CLOCK;
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 static unsigned disk_led_gpio = 16;
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 static unsigned disk_led_active_low = 1;
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 static unsigned reboot_part = 0;
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+static unsigned w1_gpio_pin = W1_GPIO;
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+static unsigned w1_gpio_pullup = W1_PULLUP;
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 static bool vc_i2c_override = false;
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						|
 
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 static unsigned use_dt = 0;
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@@ -303,6 +311,20 @@ static struct platform_device bcm2708_dm
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 	.num_resources = ARRAY_SIZE(bcm2708_dmaengine_resources),
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 };
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						|
 
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+#if defined(CONFIG_W1_MASTER_GPIO) || defined(CONFIG_W1_MASTER_GPIO_MODULE)
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+static struct w1_gpio_platform_data w1_gpio_pdata = {
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+	.pin = W1_GPIO,
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+        .ext_pullup_enable_pin = W1_PULLUP,
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+	.is_open_drain = 0,
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+};
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+
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+static struct platform_device w1_device = {
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+	.name = "w1-gpio",
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+	.id = -1,
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+	.dev.platform_data = &w1_gpio_pdata,
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+};
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+#endif
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+
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 static u64 fb_dmamask = DMA_BIT_MASK(DMA_MASK_BITS_COMMON);
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						|
 
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 static struct platform_device bcm2708_fb_device = {
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@@ -729,6 +751,11 @@ void __init bcm2708_init(void)
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 #ifdef CONFIG_BCM2708_GPIO
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 	bcm_register_device_dt(&bcm2708_gpio_device);
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 #endif
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+#if defined(CONFIG_W1_MASTER_GPIO) || defined(CONFIG_W1_MASTER_GPIO_MODULE)
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+	w1_gpio_pdata.pin = w1_gpio_pin;
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+	w1_gpio_pdata.ext_pullup_enable_pin = w1_gpio_pullup;
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+	bcm_register_device_dt(&w1_device);
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+#endif
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 	bcm_register_device_dt(&bcm2708_fb_device);
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 	bcm_register_device_dt(&bcm2708_usb_device);
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						|
 
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@@ -942,5 +969,7 @@ module_param(uart_clock, uint, 0644);
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 module_param(disk_led_gpio, uint, 0644);
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 module_param(disk_led_active_low, uint, 0644);
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 module_param(reboot_part, uint, 0644);
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+module_param(w1_gpio_pin, uint, 0644);
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+module_param(w1_gpio_pullup, uint, 0644);
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 module_param(vc_i2c_override, bool, 0644);
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 MODULE_PARM_DESC(vc_i2c_override, "Allow the use of VC's I2C peripheral.");
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--- a/arch/arm/mach-bcm2709/bcm2709.c
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+++ b/arch/arm/mach-bcm2709/bcm2709.c
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@@ -36,6 +36,7 @@
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 #include <linux/of_platform.h>
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 #include <linux/spi/spi.h>
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 #include <linux/gpio/machine.h>
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+#include <linux/w1-gpio.h>
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 #include <linux/version.h>
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 #include <linux/clkdev.h>
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@@ -79,12 +80,19 @@
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  */
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 #define DMA_MASK_BITS_COMMON 32
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+// use GPIO 4 for the one-wire GPIO pin, if enabled
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+#define W1_GPIO 4
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+// ensure one-wire GPIO pullup is disabled by default
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+#define W1_PULLUP -1
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+
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 /* command line parameters */
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 static unsigned boardrev, serial;
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 static unsigned uart_clock = UART0_CLOCK;
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 static unsigned disk_led_gpio = 16;
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 static unsigned disk_led_active_low = 1;
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 static unsigned reboot_part = 0;
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+static unsigned w1_gpio_pin = W1_GPIO;
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+static unsigned w1_gpio_pullup = W1_PULLUP;
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 static bool vc_i2c_override = false;
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 static unsigned use_dt = 0;
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@@ -313,6 +321,20 @@ static struct platform_device bcm2708_dm
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 	.num_resources = ARRAY_SIZE(bcm2708_dmaengine_resources),
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 };
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+#if defined(CONFIG_W1_MASTER_GPIO) || defined(CONFIG_W1_MASTER_GPIO_MODULE)
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+static struct w1_gpio_platform_data w1_gpio_pdata = {
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+	.pin = W1_GPIO,
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+        .ext_pullup_enable_pin = W1_PULLUP,
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+	.is_open_drain = 0,
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+};
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+
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+static struct platform_device w1_device = {
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+	.name = "w1-gpio",
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+	.id = -1,
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+	.dev.platform_data = &w1_gpio_pdata,
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+};
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+#endif
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+
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 static u64 fb_dmamask = DMA_BIT_MASK(DMA_MASK_BITS_COMMON);
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 static struct platform_device bcm2708_fb_device = {
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@@ -749,6 +771,11 @@ void __init bcm2709_init(void)
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 #ifdef CONFIG_BCM2708_GPIO
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 	bcm_register_device_dt(&bcm2708_gpio_device);
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 #endif
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+#if defined(CONFIG_W1_MASTER_GPIO) || defined(CONFIG_W1_MASTER_GPIO_MODULE)
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+	w1_gpio_pdata.pin = w1_gpio_pin;
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+	w1_gpio_pdata.ext_pullup_enable_pin = w1_gpio_pullup;
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+	bcm_register_device_dt(&w1_device);
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+#endif
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 	bcm_register_device_dt(&bcm2708_fb_device);
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 	bcm_register_device_dt(&bcm2708_usb_device);
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@@ -1110,5 +1137,7 @@ module_param(uart_clock, uint, 0644);
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 module_param(disk_led_gpio, uint, 0644);
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 module_param(disk_led_active_low, uint, 0644);
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 module_param(reboot_part, uint, 0644);
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+module_param(w1_gpio_pin, uint, 0644);
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+module_param(w1_gpio_pullup, uint, 0644);
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 module_param(vc_i2c_override, bool, 0644);
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 MODULE_PARM_DESC(vc_i2c_override, "Allow the use of VC's I2C peripheral.");
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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 +23,19 @@
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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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+static int w1_gpio_pullup_orig = 0;
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+module_param_named(pullup, w1_gpio_pullup, int, 0);
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+MODULE_PARM_DESC(pullup, "Enable parasitic power (power on data) mode");
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+static int w1_gpio_pullup_pin = -1;
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+static int w1_gpio_pullup_pin_orig = -1;
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+module_param_named(extpullup, w1_gpio_pullup_pin, int, 0);
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+MODULE_PARM_DESC(extpullup, "GPIO external pullup pin number");
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+static int w1_gpio_pin = -1;
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+static int w1_gpio_pin_orig = -1;
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+module_param_named(gpiopin, w1_gpio_pin, int, 0);
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+MODULE_PARM_DESC(gpiopin, "GPIO pin number");
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+
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 static u8 w1_gpio_set_pullup(void *data, int delay)
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 {
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 	struct w1_gpio_platform_data *pdata = data;
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@@ -67,6 +80,16 @@ 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 const struct of_device_id w1_gpio_dt_ids[] = {
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 	{ .compatible = "w1-gpio" },
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@@ -80,6 +103,7 @@ static int w1_gpio_probe_dt(struct platf
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 	struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
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 	struct device_node *np = pdev->dev.of_node;
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 	int gpio;
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+	u32 value;
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 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
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 	if (!pdata)
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@@ -88,6 +112,9 @@ static int w1_gpio_probe_dt(struct platf
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 	if (of_get_property(np, "linux,open-drain", NULL))
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 		pdata->is_open_drain = 1;
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+	if (of_property_read_u32(np, "rpi,parasitic-power", &value) == 0)
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+	    pdata->parasitic_power = (value != 0);
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+
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 	gpio = of_get_gpio(np, 0);
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 	if (gpio < 0) {
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 		if (gpio != -EPROBE_DEFER)
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@@ -103,7 +130,7 @@ static int w1_gpio_probe_dt(struct platf
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 	if (gpio == -EPROBE_DEFER)
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 		return gpio;
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 	/* ignore other errors as the pullup gpio is optional */
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-	pdata->ext_pullup_enable_pin = gpio;
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+	pdata->ext_pullup_enable_pin = (gpio >= 0) ? gpio : -1;
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 	pdev->dev.platform_data = pdata;
 | 
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@@ -113,13 +140,15 @@ static int w1_gpio_probe_dt(struct platf
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 static int w1_gpio_probe(struct platform_device *pdev)
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 {
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 	struct w1_bus_master *master;
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-	struct w1_gpio_platform_data *pdata;
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+	struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
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 	int err;
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-	if (of_have_populated_dt()) {
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-		err = w1_gpio_probe_dt(pdev);
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-		if (err < 0)
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-			return err;
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+	if(pdata == NULL) {
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+		if (of_have_populated_dt()) {
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+			err = w1_gpio_probe_dt(pdev);
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+			if (err < 0)
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+				return err;
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+		}
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 	}
 | 
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 	pdata = dev_get_platdata(&pdev->dev);
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@@ -136,6 +165,22 @@ static int w1_gpio_probe(struct platform
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 		return -ENOMEM;
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 	}
 | 
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+	w1_gpio_pin_orig = pdata->pin;
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+	w1_gpio_pullup_pin_orig = pdata->ext_pullup_enable_pin;
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+	w1_gpio_pullup_orig = pdata->parasitic_power;
 | 
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+
 | 
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+	if(gpio_is_valid(w1_gpio_pin)) {
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+		pdata->pin = w1_gpio_pin;
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+		pdata->ext_pullup_enable_pin = -1;
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+		pdata->parasitic_power = -1;
 | 
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+	}
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+	pdata->parasitic_power |= w1_gpio_pullup;
 | 
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+	if(gpio_is_valid(w1_gpio_pullup_pin)) {
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+		pdata->ext_pullup_enable_pin = w1_gpio_pullup_pin;
 | 
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+	}
 | 
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+
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+	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);
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+
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 	err = devm_gpio_request(&pdev->dev, pdata->pin, "w1");
 | 
						|
 	if (err) {
 | 
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 		dev_err(&pdev->dev, "gpio_request (pin) failed\n");
 | 
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@@ -165,6 +210,14 @@ static int w1_gpio_probe(struct platform
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 		master->set_pullup = w1_gpio_set_pullup;
 | 
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 	}
 | 
						|
 
 | 
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+	if (pdata->parasitic_power) {
 | 
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+		if (pdata->is_open_drain)
 | 
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+			printk(KERN_ERR "w1-gpio 'pullup'(parasitic power) "
 | 
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+			       "option doesn't work with open drain GPIO\n");
 | 
						|
+		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);
 | 
						|
 	if (err) {
 | 
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 		dev_err(&pdev->dev, "w1_add_master device failed\n");
 | 
						|
@@ -195,6 +248,10 @@ static int w1_gpio_remove(struct platfor
 | 
						|
 
 | 
						|
 	w1_remove_master_device(master);
 | 
						|
 
 | 
						|
+	pdata->pin = w1_gpio_pin_orig;
 | 
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+	pdata->ext_pullup_enable_pin = w1_gpio_pullup_pin_orig;
 | 
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+	pdata->parasitic_power = w1_gpio_pullup_orig;
 | 
						|
+
 | 
						|
 	return 0;
 | 
						|
 }
 | 
						|
 
 | 
						|
--- a/drivers/w1/w1.h
 | 
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+++ 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);
 | 
						|
 };
 | 
						|
--- a/drivers/w1/w1_int.c
 | 
						|
+++ b/drivers/w1/w1_int.c
 | 
						|
@@ -123,6 +123,20 @@ int w1_add_master_device(struct w1_bus_m
 | 
						|
 		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). */
 | 
						|
--- a/drivers/w1/w1_io.c
 | 
						|
+++ b/drivers/w1/w1_io.c
 | 
						|
@@ -134,10 +134,22 @@ 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;
 | 
						|
 	}
 | 
						|
 }
 | 
						|
--- 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;
 |