target/linux/bcm27xx/patches-5.4/950-0528-reset-simple-Add-reset-callback.patch

   1 From 66deff85fee24ecd7b0ffa2901711aa8f026fcfa Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Tue, 28 Jan 2020 16:22:20 +0100
   4 Subject: [PATCH] reset: simple: Add reset callback
   5
   6 The reset-simple code lacks a reset callback that is still pretty easy to
   7 implement. The only real thing to consider is the delay needed for a device
   8 to be reset, so let's expose that as part of the reset-simple driver data.
   9
  10 Cc: Philipp Zabel <p.zabel@pengutronix.de>
  11 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  12 ---
  13  drivers/reset/reset-simple.c       | 24 ++++++++++++++++++++++++
  14  include/linux/reset/reset-simple.h |  6 ++++++
  15  2 files changed, 30 insertions(+)
  16
  17 --- a/drivers/reset/reset-simple.c
  18 +++ b/drivers/reset/reset-simple.c
  19 @@ -11,6 +11,7 @@
  20   * Maxime Ripard <maxime.ripard@free-electrons.com>
  21   */
  22
  23 +#include <linux/delay.h>
  24  #include <linux/device.h>
  25  #include <linux/err.h>
  26  #include <linux/io.h>
  27 @@ -63,6 +64,28 @@ static int reset_simple_deassert(struct
  28         return reset_simple_update(rcdev, id, false);
  29  }
  30
  31 +static int reset_simple_reset(struct reset_controller_dev *rcdev,
  32 +                              unsigned long id)
  33 +{
  34 +       struct reset_simple_data *data = to_reset_simple_data(rcdev);
  35 +       int ret;
  36 +
  37 +       if (!data->reset_us)
  38 +               return -ENOTSUPP;
  39 +
  40 +       ret = reset_simple_assert(rcdev, id);
  41 +       if (ret)
  42 +               return ret;
  43 +
  44 +       usleep_range(data->reset_us, data->reset_us * 2);
  45 +
  46 +       ret = reset_simple_deassert(rcdev, id);
  47 +       if (ret)
  48 +               return ret;
  49 +
  50 +       return 0;
  51 +}
  52 +
  53  static int reset_simple_status(struct reset_controller_dev *rcdev,
  54                                unsigned long id)
  55  {
  56 @@ -80,6 +103,7 @@ static int reset_simple_status(struct re
  57  const struct reset_control_ops reset_simple_ops = {
  58         .assert         = reset_simple_assert,
  59         .deassert       = reset_simple_deassert,
  60 +       .reset          = reset_simple_reset,
  61         .status         = reset_simple_status,
  62  };
  63  EXPORT_SYMBOL_GPL(reset_simple_ops);
  64 --- a/include/linux/reset/reset-simple.h
  65 +++ b/include/linux/reset/reset-simple.h
  66 @@ -27,6 +27,11 @@
  67   * @status_active_low: if true, bits read back as cleared while the reset is
  68   *                     asserted. Otherwise, bits read back as set while the
  69   *                     reset is asserted.
  70 + * @reset_us: Minimum delay in microseconds needed that needs to be
  71 + *            waited for between an assert and a deassert to reset the
  72 + *            device. If multiple consumers with different delay
  73 + *            requirements are connected to this controller, it must
  74 + *            be the largest minimum delay.
  75   */
  76  struct reset_simple_data {
  77         spinlock_t                      lock;
  78 @@ -34,6 +39,7 @@ struct reset_simple_data {
  79         struct reset_controller_dev     rcdev;
  80         bool                            active_low;
  81         bool                            status_active_low;
  82 +       unsigned int                    reset_us;
  83  };
  84
  85  extern const struct reset_control_ops reset_simple_ops;