Hi Krzysztof,
thank you very much for your review!
Am 19.03.2025 um 10:03 schrieb Krzysztof Kozlowski:
On Tue, Mar 18, 2025 at 08:28:58AM +0100, Matthias Fend wrote:
+
+static int tps6131x_reset_chip(struct tps6131x *tps6131x)
+{
+ int ret;
+
+ if (IS_ERR_OR_NULL(tps6131x->reset_gpio)) {
No, only check for non-null, see comment in probe().
ACK
+ ret = regmap_update_bits(tps6131x->regmap, TPS6131X_REG_0, TPS6131X_REG_0_RESET,
+ TPS6131X_REG_0_RESET);
+ if (ret)
+ return ret;
+
+ fsleep(100);
+
+ ret = regmap_update_bits(tps6131x->regmap, TPS6131X_REG_0, TPS6131X_REG_0_RESET, 0);
+ if (ret)
+ return ret;
+ } else {
+ gpiod_set_value_cansleep(tps6131x->reset_gpio, 1);
+ fsleep(10);
+ gpiod_set_value_cansleep(tps6131x->reset_gpio, 0);
+ fsleep(100);
+ }
+
+ return 0;
+}
+
+static int tps6131x_init_chip(struct tps6131x *tps6131x)
+{
+ u32 reg4, reg5, reg6;
+ int ret;
+
+ reg4 = tps6131x->valley_current_limit ? TPS6131X_REG_4_ILIM : 0;
+ ret = regmap_write(tps6131x->regmap, TPS6131X_REG_4, reg4);
+ if (ret)
+ return ret;
+
+ reg5 = TPS6131X_REG_5_ENPSM | TPS6131X_REG_5_STSTRB1_DIR | TPS6131X_REG_5_GPIOTYPE;
+ if (tps6131x->chan1_en)
+ reg5 |= TPS6131X_REG_5_ENLED1;
+
+ if (tps6131x->chan2_en)
+ reg5 |= TPS6131X_REG_5_ENLED2;
+
+ if (tps6131x->chan3_en)
+ reg5 |= TPS6131X_REG_5_ENLED3;
+ ret = regmap_write(tps6131x->regmap, TPS6131X_REG_5, reg5);
+ if (ret)
+ return ret;
+
+ reg6 = TPS6131X_REG_6_ENTS;
+ ret = regmap_write(tps6131x->regmap, TPS6131X_REG_6, reg6);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int tps6131x_set_mode(struct tps6131x *tps6131x, enum tps6131x_mode mode, bool force)
+{
+ u8 val;
+
+ val = mode << TPS6131X_REG_1_MODE_SHIFT;
+
+ return regmap_update_bits_base(tps6131x->regmap, TPS6131X_REG_1, TPS6131X_REG_1_MODE, val,
+ NULL, false, force);
+}
+
+static void tps6131x_torch_refresh_handler(struct work_struct *work)
+{
+ struct tps6131x *tps6131x = container_of(work, struct tps6131x, torch_refresh_work.work);
+
+ guard(mutex)(&tps6131x->lock);
+
+ tps6131x_set_mode(tps6131x, TPS6131X_MODE_TORCH, true);
+
+ schedule_delayed_work(&tps6131x->torch_refresh_work,
+ TPS6131X_TORCH_REFRESH_INTERVAL_JIFFIES);
+}
+
+static int tps6131x_brightness_set(struct led_classdev *cdev, enum led_brightness brightness)
+{
+ struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(cdev);
+ struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+ u32 num_chans;
+ u32 steps_chan13, steps_chan2;
+ u32 steps_remaining;
+ u8 reg0;
+ int ret;
+
+ cancel_delayed_work_sync(&tps6131x->torch_refresh_work);
+
+ guard(mutex)(&tps6131x->lock);
+
+ /*
+ * The brightness parameter uses the number of current steps as the unit (not the current
+ * value itself). Since the reported step size can vary depending on the configuration,
+ * this value must be converted into actual register steps.
+ */
+ steps_remaining = (brightness * tps6131x->step_torch_current_ma) / TPS6131X_TORCH_STEP_I_MA;
+
+ num_chans = tps6131x->chan1_en + tps6131x->chan2_en + tps6131x->chan3_en;
+
+ /*
+ * The currents are distributed as evenly as possible across the activated channels.
+ * Since channels 1 and 3 share the same register setting, they always use the same current
+ * value. Channel 2 supports higher currents and thus takes over the remaining additional
+ * portion that cannot be covered by the other channels.
+ */
+ steps_chan13 = min_t(u32, steps_remaining / num_chans,
+ TPS6131X_TORCH_MAX_I_CHAN13_MA / TPS6131X_TORCH_STEP_I_MA);
+ if (tps6131x->chan1_en)
+ steps_remaining -= steps_chan13;
+ if (tps6131x->chan3_en)
+ steps_remaining -= steps_chan13;
+
+ steps_chan2 = min_t(u32, steps_remaining,
+ TPS6131X_TORCH_MAX_I_CHAN2_MA / TPS6131X_TORCH_STEP_I_MA);
+
+ reg0 = (steps_chan13 << TPS6131X_REG_0_DCLC13_SHIFT) |
+ (steps_chan2 << TPS6131X_REG_0_DCLC2_SHIFT);
Looks like guard should start here... or you are not synchronizing
hardware access but more.
I just found it clearer to have the lock at the beginning.
But of course, I can easily move the lock to this position.
+ ret = regmap_update_bits(tps6131x->regmap, TPS6131X_REG_0,
+ TPS6131X_REG_0_DCLC13 | TPS6131X_REG_0_DCLC2, reg0);
+ if (ret < 0)
+ return ret;
+
+ ret = tps6131x_set_mode(tps6131x, brightness ? TPS6131X_MODE_TORCH : TPS6131X_MODE_SHUTDOWN,
+ true);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * In order to use both the flash and the video light functions purely via the I2C
+ * interface, STRB1 must be low. If STRB1 is low, then the video light watchdog timer
+ * is also active, which puts the device into the shutdown state after around 13 seconds.
+ * To prevent this, the mode must be refreshed within the watchdog timeout.
+ */
+ if (brightness)
+ schedule_delayed_work(&tps6131x->torch_refresh_work,
+ TPS6131X_TORCH_REFRESH_INTERVAL_JIFFIES);
+
+ return 0;
+}
+
+static int tps6131x_strobe_set(struct led_classdev_flash *fled_cdev, bool state)
+{
+ struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+ int ret;
+
+ guard(mutex)(&tps6131x->lock);
+
+ ret = tps6131x_set_mode(tps6131x, state ? TPS6131X_MODE_FLASH : TPS6131X_MODE_SHUTDOWN,
+ true);
+ if (ret < 0)
+ return ret;
+
+ if (state) {
+ ret = regmap_update_bits_base(tps6131x->regmap, TPS6131X_REG_3, TPS6131X_REG_3_SFT,
+ TPS6131X_REG_3_SFT, NULL, false, true);
+ if (ret)
+ return ret;
+ }
+
+ ret = regmap_update_bits_base(tps6131x->regmap, TPS6131X_REG_3, TPS6131X_REG_3_SFT, 0, NULL,
+ false, true);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int tps6131x_flash_brightness_set(struct led_classdev_flash *fled_cdev, u32 brightness)
+{
+ struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+ u32 num_chans;
+ u32 steps_chan13, steps_chan2;
+ u32 steps_remaining;
+ int ret;
+
+ guard(mutex)(&tps6131x->lock);
+
+ steps_remaining = brightness / TPS6131X_FLASH_STEP_I_MA;
+ num_chans = tps6131x->chan1_en + tps6131x->chan2_en + tps6131x->chan3_en;
+ steps_chan13 = min_t(u32, steps_remaining / num_chans,
+ TPS6131X_FLASH_MAX_I_CHAN13_MA / TPS6131X_FLASH_STEP_I_MA);
+ if (tps6131x->chan1_en)
+ steps_remaining -= steps_chan13;
+ if (tps6131x->chan3_en)
+ steps_remaining -= steps_chan13;
+ steps_chan2 = min_t(u32, steps_remaining,
+ TPS6131X_FLASH_MAX_I_CHAN2_MA / TPS6131X_FLASH_STEP_I_MA);
+
Same here
ACK
+ ret = regmap_update_bits(tps6131x->regmap, TPS6131X_REG_2, TPS6131X_REG_2_FC13,
+ steps_chan13 << TPS6131X_REG_2_FC13_SHIFT);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(tps6131x->regmap, TPS6131X_REG_1, TPS6131X_REG_1_FC2,
+ steps_chan2 << TPS6131X_REG_1_FC2_SHIFT);
+ if (ret < 0)
+ return ret;
+
+ fled_cdev->brightness.val = brightness;
+
+ return 0;
+}
+
+static int tps6131x_flash_timeout_set(struct led_classdev_flash *fled_cdev, u32 timeout_us)
+{
+ const struct tps6131x_timer_config *timer_config;
+ struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+ u8 reg3;
+ int ret;
+
+ guard(mutex)(&tps6131x->lock);
+
+ timer_config = tps6131x_find_closest_timer_config(timeout_us);
+
+ reg3 = timer_config->val << TPS6131X_REG_3_STIM_SHIFT;
+ if (timer_config->range)
+ reg3 |= TPS6131X_REG_3_SELSTIM_TO;
+
+ ret = regmap_update_bits(tps6131x->regmap, TPS6131X_REG_3,
+ TPS6131X_REG_3_STIM | TPS6131X_REG_3_SELSTIM_TO, reg3);
+ if (ret < 0)
+ return ret;
+
+ fled_cdev->timeout.val = timer_config->time_us;
+
+ return 0;
+}
+
+static int tps6131x_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
+{
+ struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+ unsigned int reg3;
+ int ret;
+
+ guard(mutex)(&tps6131x->lock);
+
+ ret = regmap_read_bypassed(tps6131x->regmap, TPS6131X_REG_3, ®3);
+ if (ret)
+ return ret;
+
+ *state = !!(reg3 & TPS6131X_REG_3_SFT);
+
+ return 0;
+}
+
+static int tps6131x_flash_fault_get(struct led_classdev_flash *fled_cdev, u32 *fault)
+{
+ struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+ unsigned int reg3, reg4, reg6;
+ int ret;
+
+ *fault = 0;
+
Why no lock here?
The individual regmap operations are already protected by the internal
lock. If reading from a register has no other problematic effects on the
overall function, then no additional lock is needed.
I noticed that the lock in tps6131x_strobe_get() is no longer needed.
I'll removed that as well.
+ ret = regmap_read_bypassed(tps6131x->regmap, TPS6131X_REG_3, ®3);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_read_bypassed(tps6131x->regmap, TPS6131X_REG_4, ®4);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_read_bypassed(tps6131x->regmap, TPS6131X_REG_6, ®6);
+ if (ret < 0)
+ return ret;
+
+ if (reg3 & TPS6131X_REG_3_HPFL)
+ *fault |= LED_FAULT_SHORT_CIRCUIT;
+
+ if (reg3 & TPS6131X_REG_3_SELSTIM_TO)
+ *fault |= LED_FAULT_TIMEOUT;
+
+ if (reg4 & TPS6131X_REG_4_HOTDIE_HI)
+ *fault |= LED_FAULT_OVER_TEMPERATURE;
+
+ if (reg6 & (TPS6131X_REG_6_LEDHOT | TPS6131X_REG_6_LEDWARN))
+ *fault |= LED_FAULT_LED_OVER_TEMPERATURE;
+
+ if (!(reg6 & TPS6131X_REG_6_LEDHDR))
+ *fault |= LED_FAULT_UNDER_VOLTAGE;
+
+ if (reg6 & TPS6131X_REG_6_LEDHOT) {
+ ret = regmap_update_bits_base(tps6131x->regmap, TPS6131X_REG_6,
+ TPS6131X_REG_6_LEDHOT, 0, NULL, false, true);
And this is not locked?
The read modify write operation is protected by regmap. Since this
operation does not interact with any other functions, no lock is needed
here.
+ if (ret < 0)
+ return ret;
+ }
+
...
+
+static int tps6131x_flash_external_strobe_set(struct v4l2_flash *v4l2_flash, bool enable)
+{
+ struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
+ struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+
+ guard(mutex)(&tps6131x->lock);
+
+ return tps6131x_set_mode(tps6131x, enable ? TPS6131X_MODE_FLASH : TPS6131X_MODE_SHUTDOWN,
+ false);
+}
+
+static const struct v4l2_flash_ops tps6131x_v4l2_flash_ops = {
+ .external_strobe_set = tps6131x_flash_external_strobe_set,
+};
+
+static int tps6131x_v4l2_setup(struct tps6131x *tps6131x)
+{
+ struct v4l2_flash_config v4l2_cfg = { 0 };
+ struct led_flash_setting *intensity = &v4l2_cfg.intensity;
+
+ if (!IS_BUILTIN(CONFIG_V4L2_FLASH_LED_CLASS))
Why builtin? That's a tristate, so I don't get why driver and v4l flash
cannot be modules. You wanted REACHABLE probably... but then it is
anyway discouraged practice leading to runtime debugging. So actually
you want CONFIG_V4L2_FLASH_LED_CLASS || !CONFIG_V4L2_FLASH_LED_CLASS
dependency.
Okay, I'll add 'depends on V4L2_FLASH_LED_CLASS ||
!V4L2_FLASH_LED_CLASS' to the Kconfig entry and do the check in the
driver like this:
if (!IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS))
return 0;
Is this solution okay for you?
See Kconfig description.
+ return 0;
+
+ intensity->min = tps6131x->step_torch_current_ma;
+ intensity->max = tps6131x->max_torch_current_ma;
+ intensity->step = tps6131x->step_torch_current_ma;
+ intensity->val = intensity->min;
+
+ strscpy(v4l2_cfg.dev_name, tps6131x->fled_cdev.led_cdev.dev->kobj.name,
+ sizeof(v4l2_cfg.dev_name));
+
+ v4l2_cfg.has_external_strobe = true;
+ v4l2_cfg.flash_faults = LED_FAULT_TIMEOUT | LED_FAULT_OVER_TEMPERATURE |
+ LED_FAULT_SHORT_CIRCUIT | LED_FAULT_UNDER_VOLTAGE |
+ LED_FAULT_LED_OVER_TEMPERATURE;
+
+ tps6131x->v4l2_flash = v4l2_flash_init(tps6131x->dev, tps6131x->led_node,
+ &tps6131x->fled_cdev, &tps6131x_v4l2_flash_ops,
+ &v4l2_cfg);
+ if (IS_ERR(tps6131x->v4l2_flash)) {
+ dev_err(tps6131x->dev, "Failed to initialize v4l2 flash LED\n");
+ return PTR_ERR(tps6131x->v4l2_flash);
+ }
+
+ return 0;
+}
+
+static int tps6131x_probe(struct i2c_client *client)
+{
+ struct tps6131x *tps6131x;
+ int ret;
+
+ tps6131x = devm_kzalloc(&client->dev, sizeof(*tps6131x), GFP_KERNEL);
+ if (!tps6131x)
+ return -ENOMEM;
+
+ tps6131x->dev = &client->dev;
+ i2c_set_clientdata(client, tps6131x);
+ mutex_init(&tps6131x->lock);
+ INIT_DELAYED_WORK(&tps6131x->torch_refresh_work, tps6131x_torch_refresh_handler);
+
+ ret = tps6131x_parse_node(tps6131x);
+ if (ret)
+ return -ENODEV;
+
+ tps6131x->regmap = devm_regmap_init_i2c(client, &tps6131x_regmap);
+ if (IS_ERR(tps6131x->regmap)) {
+ ret = PTR_ERR(tps6131x->regmap);
+ dev_err(&client->dev, "Failed to allocate register map\n");
+ return ret;
Syntax is:
return dev_err_probe
Of course. ACK
+ }
+
+ tps6131x->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH);
You should handle IS_ERR
ACK
Thanks!
~Matthias
Best regards,
Krzysztof
