target/linux/brcm2708/patches-3.18/0103-w1-gpio-Sort-out-the-pullup-parasitic-power-tangle.patch

   1 From 8ceb69e8548f27305e37866ec3b81a79e1402b1a Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.org>
   3 Date: Wed, 4 Feb 2015 12:59:36 +0000
   4 Subject: [PATCH 103/114] w1-gpio: Sort out the pullup/parasitic power tangle
   5
   6 ---
   7  arch/arm/boot/dts/w1-gpio-overlay.dts        |  4 +++-
   8  arch/arm/boot/dts/w1-gpio-pullup-overlay.dts |  6 +++--
   9  drivers/w1/masters/w1-gpio.c                 | 36 ++++++++++++++++++----------
  10  include/linux/w1-gpio.h                      |  1 +
  11  4 files changed, 32 insertions(+), 15 deletions(-)
  12
  13 --- a/arch/arm/boot/dts/w1-gpio-overlay.dts
  14 +++ b/arch/arm/boot/dts/w1-gpio-overlay.dts
  15 @@ -1,4 +1,4 @@
  16 -// Definitions for lirc-rpi module
  17 +// Definitions for w1-gpio module (without external pullup)
  18  /dts-v1/;
  19  /plugin/;
  20
  21 @@ -14,6 +14,7 @@
  22                                 pinctrl-names = "default";
  23                                 pinctrl-0 = <&w1_pins>;
  24                                 gpios = <&gpio 4 0>;
  25 +                               rpi,parasitic-power = <0>;
  26                                 status = "okay";
  27                         };
  28                 };
  29 @@ -33,5 +34,6 @@
  30         __overrides__ {
  31                 gpiopin =       <&w1>,"gpios:4",
  32                                 <&w1_pins>,"brcm,pins:0";
  33 +               pullup =        <&w1>,"rpi,parasitic-power:0";
  34         };
  35  };
  36 --- a/arch/arm/boot/dts/w1-gpio-pullup-overlay.dts
  37 +++ b/arch/arm/boot/dts/w1-gpio-pullup-overlay.dts
  38 @@ -1,4 +1,4 @@
  39 -// Definitions for lirc-rpi module
  40 +// Definitions for w1-gpio module (with external pullup)
  41  /dts-v1/;
  42  /plugin/;
  43
  44 @@ -14,6 +14,7 @@
  45                                 pinctrl-names = "default";
  46                                 pinctrl-0 = <&w1_pins>;
  47                                 gpios = <&gpio 4 0>, <&gpio 5 1>;
  48 +                               rpi,parasitic-power = <0>;
  49                                 status = "okay";
  50                         };
  51                 };
  52 @@ -33,7 +34,8 @@
  53         __overrides__ {
  54                 gpiopin =       <&w1>,"gpios:4",
  55                                 <&w1_pins>,"brcm,pins:0";
  56 -               pullup =        <&w1>,"gpios:16",
  57 +               extpullup =     <&w1>,"gpios:16",
  58                                 <&w1_pins>,"brcm,pins:4";
  59 +               pullup =        <&w1>,"rpi,parasitic-power:0";
  60         };
  61  };
  62 --- a/drivers/w1/masters/w1-gpio.c
  63 +++ b/drivers/w1/masters/w1-gpio.c
  64 @@ -23,10 +23,14 @@
  65  #include "../w1.h"
  66  #include "../w1_int.h"
  67
  68 -static int w1_gpio_pullup = -1;
  69 -static int w1_gpio_pullup_orig = -1;
  70 +static int w1_gpio_pullup = 0;
  71 +static int w1_gpio_pullup_orig = 0;
  72  module_param_named(pullup, w1_gpio_pullup, int, 0);
  73 -MODULE_PARM_DESC(pullup, "GPIO pin pullup number");
  74 +MODULE_PARM_DESC(pullup, "Enable parasitic power (power on data) mode");
  75 +static int w1_gpio_pullup_pin = -1;
  76 +static int w1_gpio_pullup_pin_orig = -1;
  77 +module_param_named(extpullup, w1_gpio_pullup_pin, int, 0);
  78 +MODULE_PARM_DESC(extpullup, "GPIO external pullup pin number");
  79  static int w1_gpio_pin = -1;
  80  static int w1_gpio_pin_orig = -1;
  81  module_param_named(gpiopin, w1_gpio_pin, int, 0);
  82 @@ -99,6 +103,7 @@ static int w1_gpio_probe_dt(struct platf
  83         struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
  84         struct device_node *np = pdev->dev.of_node;
  85         int gpio;
  86 +       u32 value;
  87
  88         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
  89         if (!pdata)
  90 @@ -107,6 +112,9 @@ static int w1_gpio_probe_dt(struct platf
  91         if (of_get_property(np, "linux,open-drain", NULL))
  92                 pdata->is_open_drain = 1;
  93
  94 +       if (of_property_read_u32(np, "rpi,parasitic-power", &value) == 0)
  95 +           pdata->parasitic_power = (value != 0);
  96 +
  97         gpio = of_get_gpio(np, 0);
  98         if (gpio < 0) {
  99                 if (gpio != -EPROBE_DEFER)
 100 @@ -122,7 +130,7 @@ static int w1_gpio_probe_dt(struct platf
 101         if (gpio == -EPROBE_DEFER)
 102                 return gpio;
 103         /* ignore other errors as the pullup gpio is optional */
 104 -       pdata->ext_pullup_enable_pin = gpio;
 105 +       pdata->ext_pullup_enable_pin = (gpio >= 0) ? gpio : -1;
 106
 107         pdev->dev.platform_data = pdata;
 108
 109 @@ -158,17 +166,20 @@ static int w1_gpio_probe(struct platform
 110         }
 111
 112         w1_gpio_pin_orig = pdata->pin;
 113 -       w1_gpio_pullup_orig = pdata->ext_pullup_enable_pin;
 114 +       w1_gpio_pullup_pin_orig = pdata->ext_pullup_enable_pin;
 115 +       w1_gpio_pullup_orig = pdata->parasitic_power;
 116
 117         if(gpio_is_valid(w1_gpio_pin)) {
 118                 pdata->pin = w1_gpio_pin;
 119                 pdata->ext_pullup_enable_pin = -1;
 120 +               pdata->parasitic_power = -1;
 121         }
 122 -       if(gpio_is_valid(w1_gpio_pullup)) {
 123 -               pdata->ext_pullup_enable_pin = w1_gpio_pullup;
 124 +       pdata->parasitic_power |= w1_gpio_pullup;
 125 +       if(gpio_is_valid(w1_gpio_pullup_pin)) {
 126 +               pdata->ext_pullup_enable_pin = w1_gpio_pullup_pin;
 127         }
 128
 129 -       dev_info(&pdev->dev, "gpio pin %d, gpio pullup pin %d\n", pdata->pin, pdata->ext_pullup_enable_pin);
 130 +       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);
 131
 132         err = devm_gpio_request(&pdev->dev, pdata->pin, "w1");
 133         if (err) {
 134 @@ -199,10 +210,10 @@ static int w1_gpio_probe(struct platform
 135                 master->set_pullup = w1_gpio_set_pullup;
 136         }
 137
 138 -       if (gpio_is_valid(w1_gpio_pullup)) {
 139 +       if (pdata->parasitic_power) {
 140                 if (pdata->is_open_drain)
 141 -                       printk(KERN_ERR "w1-gpio 'pullup' option "
 142 -                              "doesn't work with open drain GPIO\n");
 143 +                       printk(KERN_ERR "w1-gpio 'pullup'(parasitic power) "
 144 +                              "option doesn't work with open drain GPIO\n");
 145                 else
 146                         master->bitbang_pullup = w1_gpio_bitbang_pullup;
 147         }
 148 @@ -238,7 +249,8 @@ static int w1_gpio_remove(struct platfor
 149         w1_remove_master_device(master);
 150
 151         pdata->pin = w1_gpio_pin_orig;
 152 -       pdata->ext_pullup_enable_pin = w1_gpio_pullup_orig;
 153 +       pdata->ext_pullup_enable_pin = w1_gpio_pullup_pin_orig;
 154 +       pdata->parasitic_power = w1_gpio_pullup_orig;
 155
 156         return 0;
 157  }
 158 --- a/include/linux/w1-gpio.h
 159 +++ b/include/linux/w1-gpio.h
 160 @@ -18,6 +18,7 @@
 161  struct w1_gpio_platform_data {
 162         unsigned int pin;
 163         unsigned int is_open_drain:1;
 164 +       unsigned int parasitic_power:1;
 165         void (*enable_external_pullup)(int enable);
 166         unsigned int ext_pullup_enable_pin;
 167         unsigned int pullup_duration;