target/linux/generic/backport-6.1/815-v6.7-5-leds-turris-omnia-Fix-brightness-setting-and-trigger.patch

   1 From ffec49d391c5f0195360912b216aa24dbc9b53c8 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Marek=20Beh=C3=BAn?= <kabel@kernel.org>
   3 Date: Mon, 16 Oct 2023 16:15:38 +0200
   4 Subject: [PATCH] leds: turris-omnia: Fix brightness setting and trigger
   5  activating
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 I have improperly refactored commits
  11   4d5ed2621c24 ("leds: turris-omnia: Make set_brightness() more efficient")
  12 and
  13   aaf38273cf76 ("leds: turris-omnia: Support HW controlled mode via private trigger")
  14 after Lee requested a change in API semantics of the new functions I
  15 introduced in commit
  16   28350bc0ac77 ("leds: turris-omnia: Do not use SMBUS calls").
  17
  18 Before the change, the function omnia_cmd_write_u8() returned 0 on
  19 success, and afterwards it returned a positive value (number of bytes
  20 written). The latter version was applied, but the following commits did
  21 not properly account for this change.
  22
  23 This results in non-functional LED's .brightness_set_blocking() and
  24 trigger's .activate() methods.
  25
  26 The main reasoning behind the semantics change was that read/write
  27 methods should return the number of read/written bytes on success.
  28 It was pointed to me [1] that this is not always true (for example the
  29 regmap API does not do so), and since the driver never uses this number
  30 of read/written bytes information, I decided to fix this issue by
  31 changing the functions to the original semantics (return 0 on success).
  32
  33 [1] https://lore.kernel.org/linux-gpio/ZQnn+Gi0xVlsGCYA@smile.fi.intel.com/
  34
  35 Fixes: 28350bc0ac77 ("leds: turris-omnia: Do not use SMBUS calls")
  36 Signed-off-by: Marek Behún <kabel@kernel.org>
  37 ---
  38  drivers/leds/leds-turris-omnia.c | 37 +++++++++++++++++---------------
  39  1 file changed, 20 insertions(+), 17 deletions(-)
  40
  41 --- a/drivers/leds/leds-turris-omnia.c
  42 +++ b/drivers/leds/leds-turris-omnia.c
  43 @@ -60,8 +60,11 @@ struct omnia_leds {
  44  static int omnia_cmd_write_u8(const struct i2c_client *client, u8 cmd, u8 val)
  45  {
  46         u8 buf[2] = { cmd, val };
  47 +       int ret;
  48 +
  49 +       ret = i2c_master_send(client, buf, sizeof(buf));
  50
  51 -       return i2c_master_send(client, buf, sizeof(buf));
  52 +       return ret < 0 ? ret : 0;
  53  }
  54
  55  static int omnia_cmd_read_raw(struct i2c_adapter *adapter, u8 addr, u8 cmd,
  56 @@ -81,7 +84,7 @@ static int omnia_cmd_read_raw(struct i2c
  57
  58         ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs));
  59         if (likely(ret == ARRAY_SIZE(msgs)))
  60 -               return len;
  61 +               return 0;
  62         else if (ret < 0)
  63                 return ret;
  64         else
  65 @@ -91,11 +94,11 @@ static int omnia_cmd_read_raw(struct i2c
  66  static int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd)
  67  {
  68         u8 reply;
  69 -       int ret;
  70 +       int err;
  71
  72 -       ret = omnia_cmd_read_raw(client->adapter, client->addr, cmd, &reply, 1);
  73 -       if (ret < 0)
  74 -               return ret;
  75 +       err = omnia_cmd_read_raw(client->adapter, client->addr, cmd, &reply, 1);
  76 +       if (err)
  77 +               return err;
  78
  79         return reply;
  80  }
  81 @@ -236,7 +239,7 @@ static void omnia_hwtrig_deactivate(stru
  82
  83         mutex_unlock(&leds->lock);
  84
  85 -       if (err < 0)
  86 +       if (err)
  87                 dev_err(cdev->dev, "Cannot put LED to software mode: %i\n",
  88                         err);
  89  }
  90 @@ -302,7 +305,7 @@ static int omnia_led_register(struct i2c
  91         ret = omnia_cmd_write_u8(client, CMD_LED_MODE,
  92                                  CMD_LED_MODE_LED(led->reg) |
  93                                  CMD_LED_MODE_USER);
  94 -       if (ret < 0) {
  95 +       if (ret) {
  96                 dev_err(dev, "Cannot set LED %pOF to software mode: %i\n", np,
  97                         ret);
  98                 return ret;
  99 @@ -311,7 +314,7 @@ static int omnia_led_register(struct i2c
 100         /* disable the LED */
 101         ret = omnia_cmd_write_u8(client, CMD_LED_STATE,
 102                                  CMD_LED_STATE_LED(led->reg));
 103 -       if (ret < 0) {
 104 +       if (ret) {
 105                 dev_err(dev, "Cannot set LED %pOF brightness: %i\n", np, ret);
 106                 return ret;
 107         }
 108 @@ -364,7 +367,7 @@ static ssize_t brightness_store(struct d
 109  {
 110         struct i2c_client *client = to_i2c_client(dev);
 111         unsigned long brightness;
 112 -       int ret;
 113 +       int err;
 114
 115         if (kstrtoul(buf, 10, &brightness))
 116                 return -EINVAL;
 117 @@ -372,9 +375,9 @@ static ssize_t brightness_store(struct d
 118         if (brightness > 100)
 119                 return -EINVAL;
 120
 121 -       ret = omnia_cmd_write_u8(client, CMD_LED_SET_BRIGHTNESS, brightness);
 122 +       err = omnia_cmd_write_u8(client, CMD_LED_SET_BRIGHTNESS, brightness);
 123
 124 -       return ret < 0 ? ret : count;
 125 +       return err ?: count;
 126  }
 127  static DEVICE_ATTR_RW(brightness);
 128
 129 @@ -403,7 +406,7 @@ static ssize_t gamma_correction_store(st
 130         struct i2c_client *client = to_i2c_client(dev);
 131         struct omnia_leds *leds = i2c_get_clientdata(client);
 132         bool val;
 133 -       int ret;
 134 +       int err;
 135
 136         if (!leds->has_gamma_correction)
 137                 return -EOPNOTSUPP;
 138 @@ -411,9 +414,9 @@ static ssize_t gamma_correction_store(st
 139         if (kstrtobool(buf, &val) < 0)
 140                 return -EINVAL;
 141
 142 -       ret = omnia_cmd_write_u8(client, CMD_SET_GAMMA_CORRECTION, val);
 143 +       err = omnia_cmd_write_u8(client, CMD_SET_GAMMA_CORRECTION, val);
 144
 145 -       return ret < 0 ? ret : count;
 146 +       return err ?: count;
 147  }
 148  static DEVICE_ATTR_RW(gamma_correction);
 149
 150 @@ -431,7 +434,7 @@ static int omnia_mcu_get_features(const
 151
 152         err = omnia_cmd_read_raw(client->adapter, OMNIA_MCU_I2C_ADDR,
 153                                  CMD_GET_STATUS_WORD, &reply, sizeof(reply));
 154 -       if (err < 0)
 155 +       if (err)
 156                 return err;
 157
 158         /* Check whether MCU firmware supports the CMD_GET_FEAUTRES command */
 159 @@ -440,7 +443,7 @@ static int omnia_mcu_get_features(const
 160
 161         err = omnia_cmd_read_raw(client->adapter, OMNIA_MCU_I2C_ADDR,
 162                                  CMD_GET_FEATURES, &reply, sizeof(reply));
 163 -       if (err < 0)
 164 +       if (err)
 165                 return err;
 166
 167         return le16_to_cpu(reply);