target/linux/generic/backport-6.1/815-v6.7-4-leds-turris-omnia-Add-support-for-enabling-disabling.patch

   1 From 0efb3f9609d3de5a7d8c31e3835d7eb3e6adce79 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Marek=20Beh=C3=BAn?= <kabel@kernel.org>
   3 Date: Mon, 18 Sep 2023 18:11:04 +0200
   4 Subject: [PATCH 6/6] leds: turris-omnia: Add support for enabling/disabling HW
   5  gamma correction
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 If the MCU on Turris Omnia is running newer firmware versions, the LED
  11 controller supports RGB gamma correction (and enables it by default for
  12 newer boards).
  13
  14 Determine whether the gamma correction setting feature is supported and
  15 add the ability to set it via sysfs attribute file.
  16
  17 Signed-off-by: Marek Behún <kabel@kernel.org>
  18 Link: https://lore.kernel.org/r/20230918161104.20860-5-kabel@kernel.org
  19 Signed-off-by: Lee Jones <lee@kernel.org>
  20 ---
  21  .../sysfs-class-led-driver-turris-omnia       |  14 ++
  22  drivers/leds/leds-turris-omnia.c              | 137 +++++++++++++++---
  23  2 files changed, 134 insertions(+), 17 deletions(-)
  24
  25 --- a/Documentation/ABI/testing/sysfs-class-led-driver-turris-omnia
  26 +++ b/Documentation/ABI/testing/sysfs-class-led-driver-turris-omnia
  27 @@ -12,3 +12,17 @@ Description: (RW) On the front panel of
  28                 able to change this setting from software.
  29
  30                 Format: %i
  31 +
  32 +What:          /sys/class/leds/<led>/device/gamma_correction
  33 +Date:          August 2023
  34 +KernelVersion: 6.6
  35 +Contact:       Marek Behún <kabel@kernel.org>
  36 +Description:   (RW) Newer versions of the microcontroller firmware of the
  37 +               Turris Omnia router support gamma correction for the RGB LEDs.
  38 +               This feature can be enabled/disabled by writing to this file.
  39 +
  40 +               If the feature is not supported because the MCU firmware is too
  41 +               old, the file always reads as 0, and writing to the file results
  42 +               in the EOPNOTSUPP error.
  43 +
  44 +               Format: %i
  45 --- a/drivers/leds/leds-turris-omnia.c
  46 +++ b/drivers/leds/leds-turris-omnia.c
  47 @@ -15,17 +15,30 @@
  48  #define OMNIA_BOARD_LEDS       12
  49  #define OMNIA_LED_NUM_CHANNELS 3
  50
  51 -#define CMD_LED_MODE           3
  52 -#define CMD_LED_MODE_LED(l)    ((l) & 0x0f)
  53 -#define CMD_LED_MODE_USER      0x10
  54 -
  55 -#define CMD_LED_STATE          4
  56 -#define CMD_LED_STATE_LED(l)   ((l) & 0x0f)
  57 -#define CMD_LED_STATE_ON       0x10
  58 -
  59 -#define CMD_LED_COLOR          5
  60 -#define CMD_LED_SET_BRIGHTNESS 7
  61 -#define CMD_LED_GET_BRIGHTNESS 8
  62 +/* MCU controller commands at I2C address 0x2a */
  63 +#define OMNIA_MCU_I2C_ADDR             0x2a
  64 +
  65 +#define CMD_GET_STATUS_WORD            0x01
  66 +#define STS_FEATURES_SUPPORTED         BIT(2)
  67 +
  68 +#define CMD_GET_FEATURES               0x10
  69 +#define FEAT_LED_GAMMA_CORRECTION      BIT(5)
  70 +
  71 +/* LED controller commands at I2C address 0x2b */
  72 +#define CMD_LED_MODE                   0x03
  73 +#define CMD_LED_MODE_LED(l)            ((l) & 0x0f)
  74 +#define CMD_LED_MODE_USER              0x10
  75 +
  76 +#define CMD_LED_STATE                  0x04
  77 +#define CMD_LED_STATE_LED(l)           ((l) & 0x0f)
  78 +#define CMD_LED_STATE_ON               0x10
  79 +
  80 +#define CMD_LED_COLOR                  0x05
  81 +#define CMD_LED_SET_BRIGHTNESS         0x07
  82 +#define CMD_LED_GET_BRIGHTNESS         0x08
  83 +
  84 +#define CMD_SET_GAMMA_CORRECTION       0x30
  85 +#define CMD_GET_GAMMA_CORRECTION       0x31
  86
  87  struct omnia_led {
  88         struct led_classdev_mc mc_cdev;
  89 @@ -40,6 +53,7 @@ struct omnia_led {
  90  struct omnia_leds {
  91         struct i2c_client *client;
  92         struct mutex lock;
  93 +       bool has_gamma_correction;
  94         struct omnia_led leds[];
  95  };
  96
  97 @@ -50,30 +64,42 @@ static int omnia_cmd_write_u8(const stru
  98         return i2c_master_send(client, buf, sizeof(buf));
  99  }
 100
 101 -static int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd)
 102 +static int omnia_cmd_read_raw(struct i2c_adapter *adapter, u8 addr, u8 cmd,
 103 +                             void *reply, size_t len)
 104  {
 105         struct i2c_msg msgs[2];
 106 -       u8 reply;
 107         int ret;
 108
 109 -       msgs[0].addr = client->addr;
 110 +       msgs[0].addr = addr;
 111         msgs[0].flags = 0;
 112         msgs[0].len = 1;
 113         msgs[0].buf = &cmd;
 114 -       msgs[1].addr = client->addr;
 115 +       msgs[1].addr = addr;
 116         msgs[1].flags = I2C_M_RD;
 117 -       msgs[1].len = 1;
 118 -       msgs[1].buf = &reply;
 119 +       msgs[1].len = len;
 120 +       msgs[1].buf = reply;
 121
 122 -       ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 123 +       ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs));
 124         if (likely(ret == ARRAY_SIZE(msgs)))
 125 -               return reply;
 126 +               return len;
 127         else if (ret < 0)
 128                 return ret;
 129         else
 130                 return -EIO;
 131  }
 132
 133 +static int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd)
 134 +{
 135 +       u8 reply;
 136 +       int ret;
 137 +
 138 +       ret = omnia_cmd_read_raw(client->adapter, client->addr, cmd, &reply, 1);
 139 +       if (ret < 0)
 140 +               return ret;
 141 +
 142 +       return reply;
 143 +}
 144 +
 145  static int omnia_led_send_color_cmd(const struct i2c_client *client,
 146                                     struct omnia_led *led)
 147  {
 148 @@ -352,12 +378,74 @@ static ssize_t brightness_store(struct d
 149  }
 150  static DEVICE_ATTR_RW(brightness);
 151
 152 +static ssize_t gamma_correction_show(struct device *dev,
 153 +                                    struct device_attribute *a, char *buf)
 154 +{
 155 +       struct i2c_client *client = to_i2c_client(dev);
 156 +       struct omnia_leds *leds = i2c_get_clientdata(client);
 157 +       int ret;
 158 +
 159 +       if (leds->has_gamma_correction) {
 160 +               ret = omnia_cmd_read_u8(client, CMD_GET_GAMMA_CORRECTION);
 161 +               if (ret < 0)
 162 +                       return ret;
 163 +       } else {
 164 +               ret = 0;
 165 +       }
 166 +
 167 +       return sysfs_emit(buf, "%d\n", !!ret);
 168 +}
 169 +
 170 +static ssize_t gamma_correction_store(struct device *dev,
 171 +                                     struct device_attribute *a,
 172 +                                     const char *buf, size_t count)
 173 +{
 174 +       struct i2c_client *client = to_i2c_client(dev);
 175 +       struct omnia_leds *leds = i2c_get_clientdata(client);
 176 +       bool val;
 177 +       int ret;
 178 +
 179 +       if (!leds->has_gamma_correction)
 180 +               return -EOPNOTSUPP;
 181 +
 182 +       if (kstrtobool(buf, &val) < 0)
 183 +               return -EINVAL;
 184 +
 185 +       ret = omnia_cmd_write_u8(client, CMD_SET_GAMMA_CORRECTION, val);
 186 +
 187 +       return ret < 0 ? ret : count;
 188 +}
 189 +static DEVICE_ATTR_RW(gamma_correction);
 190 +
 191  static struct attribute *omnia_led_controller_attrs[] = {
 192         &dev_attr_brightness.attr,
 193 +       &dev_attr_gamma_correction.attr,
 194         NULL,
 195  };
 196  ATTRIBUTE_GROUPS(omnia_led_controller);
 197
 198 +static int omnia_mcu_get_features(const struct i2c_client *client)
 199 +{
 200 +       u16 reply;
 201 +       int err;
 202 +
 203 +       err = omnia_cmd_read_raw(client->adapter, OMNIA_MCU_I2C_ADDR,
 204 +                                CMD_GET_STATUS_WORD, &reply, sizeof(reply));
 205 +       if (err < 0)
 206 +               return err;
 207 +
 208 +       /* Check whether MCU firmware supports the CMD_GET_FEAUTRES command */
 209 +       if (!(le16_to_cpu(reply) & STS_FEATURES_SUPPORTED))
 210 +               return 0;
 211 +
 212 +       err = omnia_cmd_read_raw(client->adapter, OMNIA_MCU_I2C_ADDR,
 213 +                                CMD_GET_FEATURES, &reply, sizeof(reply));
 214 +       if (err < 0)
 215 +               return err;
 216 +
 217 +       return le16_to_cpu(reply);
 218 +}
 219 +
 220  static int omnia_leds_probe(struct i2c_client *client,
 221                             const struct i2c_device_id *id)
 222  {
 223 @@ -383,6 +471,21 @@ static int omnia_leds_probe(struct i2c_c
 224         leds->client = client;
 225         i2c_set_clientdata(client, leds);
 226
 227 +       ret = omnia_mcu_get_features(client);
 228 +       if (ret < 0) {
 229 +               dev_err(dev, "Cannot determine MCU supported features: %d\n",
 230 +                       ret);
 231 +               return ret;
 232 +       }
 233 +
 234 +       leds->has_gamma_correction = ret & FEAT_LED_GAMMA_CORRECTION;
 235 +       if (!leds->has_gamma_correction) {
 236 +               dev_info(dev,
 237 +                        "Your board's MCU firmware does not support the LED gamma correction feature.\n");
 238 +               dev_info(dev,
 239 +                        "Consider upgrading MCU firmware with the omnia-mcutool utility.\n");
 240 +       }
 241 +
 242         mutex_init(&leds->lock);
 243
 244         ret = devm_led_trigger_register(dev, &omnia_hw_trigger);