target/linux/brcm2708/patches-4.1/0119-Merge-pull-request-1059-from-pelwell-rpi-4.0.y.patch

   1 From a603c307f7348255d19b6031254aac0080e99c37 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <pelwell@users.noreply.github.com>
   3 Date: Mon, 13 Jul 2015 13:25:31 +0100
   4 Subject: [PATCH 119/222] Merge pull request #1059 from pelwell/rpi-4.0.y
   5
   6 w1_therm: Back-port locking improvements from 4.2-rc1
   7 ---
   8  Documentation/ABI/stable/sysfs-driver-w1_ds28ea00 |   6 ++
   9  Documentation/w1/slaves/w1_therm                  |  11 ++-
  10  drivers/w1/slaves/w1_therm.c                      | 102 +++++++++++++++++++++-
  11  3 files changed, 117 insertions(+), 2 deletions(-)
  12  create mode 100644 Documentation/ABI/stable/sysfs-driver-w1_ds28ea00
  13
  14 --- /dev/null
  15 +++ b/Documentation/ABI/stable/sysfs-driver-w1_ds28ea00
  16 @@ -0,0 +1,6 @@
  17 +What:          /sys/bus/w1/devices/.../w1_seq
  18 +Date:          Apr 2015
  19 +Contact:       Matt Campbell <mattrcampbell@gmail.com>
  20 +Description:   Support for the DS28EA00 chain sequence function
  21 +               see Documentation/w1/slaves/w1_therm for detailed information
  22 +Users:         any user space application which wants to communicate with DS28EA00
  23 --- a/Documentation/w1/slaves/w1_therm
  24 +++ b/Documentation/w1/slaves/w1_therm
  25 @@ -11,12 +11,14 @@ Author: Evgeniy Polyakov <johnpol@2ka.mi
  26  Description
  27  -----------
  28
  29 -w1_therm provides basic temperature conversion for ds18*20 devices.
  30 +w1_therm provides basic temperature conversion for ds18*20 devices, and the
  31 +ds28ea00 device.
  32  supported family codes:
  33  W1_THERM_DS18S20       0x10
  34  W1_THERM_DS1822                0x22
  35  W1_THERM_DS18B20       0x28
  36  W1_THERM_DS1825                0x3B
  37 +W1_THERM_DS28EA00      0x42
  38
  39  Support is provided through the sysfs w1_slave file.  Each open and
  40  read sequence will initiate a temperature conversion then provide two
  41 @@ -48,3 +50,10 @@ resistor).  The DS18b20 temperature sens
  42  maximum current draw of 1.5mA and that a 5k pullup resistor is not
  43  sufficient.  The strong pullup is designed to provide the additional
  44  current required.
  45 +
  46 +The DS28EA00 provides an additional two pins for implementing a sequence
  47 +detection algorithm.  This feature allows you to determine the physical
  48 +location of the chip in the 1-wire bus without needing pre-existing
  49 +knowledge of the bus ordering.  Support is provided through the sysfs
  50 +w1_seq file.  The file will contain a single line with an integer value
  51 +representing the device index in the bus starting at 0.
  52 --- a/drivers/w1/slaves/w1_therm.c
  53 +++ b/drivers/w1/slaves/w1_therm.c
  54 @@ -92,13 +92,24 @@ static void w1_therm_remove_slave(struct
  55  static ssize_t w1_slave_show(struct device *device,
  56         struct device_attribute *attr, char *buf);
  57
  58 +static ssize_t w1_seq_show(struct device *device,
  59 +       struct device_attribute *attr, char *buf);
  60 +
  61  static DEVICE_ATTR_RO(w1_slave);
  62 +static DEVICE_ATTR_RO(w1_seq);
  63
  64  static struct attribute *w1_therm_attrs[] = {
  65         &dev_attr_w1_slave.attr,
  66         NULL,
  67  };
  68 +
  69 +static struct attribute *w1_ds28ea00_attrs[] = {
  70 +       &dev_attr_w1_slave.attr,
  71 +       &dev_attr_w1_seq.attr,
  72 +       NULL,
  73 +};
  74  ATTRIBUTE_GROUPS(w1_therm);
  75 +ATTRIBUTE_GROUPS(w1_ds28ea00);
  76
  77  static struct w1_family_ops w1_therm_fops = {
  78         .add_slave      = w1_therm_add_slave,
  79 @@ -106,6 +117,12 @@ static struct w1_family_ops w1_therm_fop
  80         .groups         = w1_therm_groups,
  81  };
  82
  83 +static struct w1_family_ops w1_ds28ea00_fops = {
  84 +       .add_slave      = w1_therm_add_slave,
  85 +       .remove_slave   = w1_therm_remove_slave,
  86 +       .groups         = w1_ds28ea00_groups,
  87 +};
  88 +
  89  static struct w1_family w1_therm_family_DS18S20 = {
  90         .fid = W1_THERM_DS18S20,
  91         .fops = &w1_therm_fops,
  92 @@ -123,7 +140,7 @@ static struct w1_family w1_therm_family_
  93
  94  static struct w1_family w1_therm_family_DS28EA00 = {
  95         .fid = W1_THERM_DS28EA00,
  96 -       .fops = &w1_therm_fops,
  97 +       .fops = &w1_ds28ea00_fops,
  98  };
  99
 100  static struct w1_family w1_therm_family_DS1825 = {
 101 @@ -316,6 +333,89 @@ post_unlock:
 102         return ret;
 103  }
 104
 105 +#define W1_42_CHAIN    0x99
 106 +#define W1_42_CHAIN_OFF        0x3C
 107 +#define W1_42_CHAIN_OFF_INV    0xC3
 108 +#define W1_42_CHAIN_ON 0x5A
 109 +#define W1_42_CHAIN_ON_INV     0xA5
 110 +#define W1_42_CHAIN_DONE 0x96
 111 +#define W1_42_CHAIN_DONE_INV 0x69
 112 +#define W1_42_COND_READ        0x0F
 113 +#define W1_42_SUCCESS_CONFIRM_BYTE 0xAA
 114 +#define W1_42_FINISHED_BYTE 0xFF
 115 +static ssize_t w1_seq_show(struct device *device,
 116 +       struct device_attribute *attr, char *buf)
 117 +{
 118 +       struct w1_slave *sl = dev_to_w1_slave(device);
 119 +       ssize_t c = PAGE_SIZE;
 120 +       int rv;
 121 +       int i;
 122 +       u8 ack;
 123 +       u64 rn;
 124 +       struct w1_reg_num *reg_num;
 125 +       int seq = 0;
 126 +
 127 +       mutex_lock(&sl->master->bus_mutex);
 128 +       /* Place all devices in CHAIN state */
 129 +       if (w1_reset_bus(sl->master))
 130 +               goto error;
 131 +       w1_write_8(sl->master, W1_SKIP_ROM);
 132 +       w1_write_8(sl->master, W1_42_CHAIN);
 133 +       w1_write_8(sl->master, W1_42_CHAIN_ON);
 134 +       w1_write_8(sl->master, W1_42_CHAIN_ON_INV);
 135 +       msleep(sl->master->pullup_duration);
 136 +
 137 +       /* check for acknowledgment */
 138 +       ack = w1_read_8(sl->master);
 139 +       if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
 140 +               goto error;
 141 +
 142 +       /* In case the bus fails to send 0xFF, limit*/
 143 +       for (i = 0; i <= 64; i++) {
 144 +               if (w1_reset_bus(sl->master))
 145 +                       goto error;
 146 +
 147 +               w1_write_8(sl->master, W1_42_COND_READ);
 148 +               rv = w1_read_block(sl->master, (u8 *)&rn, 8);
 149 +               reg_num = (struct w1_reg_num *) &rn;
 150 +               if (reg_num->family == W1_42_FINISHED_BYTE)
 151 +                       break;
 152 +               if (sl->reg_num.id == reg_num->id)
 153 +                       seq = i;
 154 +
 155 +               w1_write_8(sl->master, W1_42_CHAIN);
 156 +               w1_write_8(sl->master, W1_42_CHAIN_DONE);
 157 +               w1_write_8(sl->master, W1_42_CHAIN_DONE_INV);
 158 +               w1_read_block(sl->master, &ack, sizeof(ack));
 159 +
 160 +               /* check for acknowledgment */
 161 +               ack = w1_read_8(sl->master);
 162 +               if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
 163 +                       goto error;
 164 +
 165 +       }
 166 +
 167 +       /* Exit from CHAIN state */
 168 +       if (w1_reset_bus(sl->master))
 169 +               goto error;
 170 +       w1_write_8(sl->master, W1_SKIP_ROM);
 171 +       w1_write_8(sl->master, W1_42_CHAIN);
 172 +       w1_write_8(sl->master, W1_42_CHAIN_OFF);
 173 +       w1_write_8(sl->master, W1_42_CHAIN_OFF_INV);
 174 +
 175 +       /* check for acknowledgment */
 176 +       ack = w1_read_8(sl->master);
 177 +       if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
 178 +               goto error;
 179 +       mutex_unlock(&sl->master->bus_mutex);
 180 +
 181 +       c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq);
 182 +       return PAGE_SIZE - c;
 183 +error:
 184 +       mutex_unlock(&sl->master->bus_mutex);
 185 +       return -EIO;
 186 +}
 187 +
 188  static int __init w1_therm_init(void)
 189  {
 190         int err, i;