diff --git a/drivers/regulator/qcom-labibb-regulator.c b/drivers/regulator/qcom-labibb-regulator.c index 4d68b69b5a524ff1427ef0bc28f6596892321802..dbb4511c3c6d9ee38577328dad8d97e117bbea90 100644 --- a/drivers/regulator/qcom-labibb-regulator.c +++ b/drivers/regulator/qcom-labibb-regulator.c @@ -17,8 +17,20 @@ #define PMI8998_LAB_REG_BASE 0xde00 #define PMI8998_IBB_REG_BASE 0xdc00 +#define PMI8998_IBB_LAB_REG_OFFSET 0x200 #define REG_LABIBB_STATUS1 0x08 + #define LABIBB_STATUS1_SC_BIT BIT(6) + #define LABIBB_STATUS1_VREG_OK_BIT BIT(7) + +#define REG_LABIBB_INT_SET_TYPE 0x11 +#define REG_LABIBB_INT_POLARITY_HIGH 0x12 +#define REG_LABIBB_INT_POLARITY_LOW 0x13 +#define REG_LABIBB_INT_LATCHED_CLR 0x14 +#define REG_LABIBB_INT_EN_SET 0x15 +#define REG_LABIBB_INT_EN_CLR 0x16 + #define LABIBB_INT_VREG_OK BIT(0) + #define LABIBB_INT_VREG_TYPE_LEVEL 0 #define REG_LABIBB_VOLTAGE 0x41 #define LABIBB_VOLTAGE_OVERRIDE_EN BIT(7) @@ -26,8 +38,7 @@ #define IBB_VOLTAGE_SET_MASK GENMASK(5, 0) #define REG_LABIBB_ENABLE_CTL 0x46 -#define LABIBB_STATUS1_VREG_OK_BIT BIT(7) -#define LABIBB_CONTROL_ENABLE BIT(7) + #define LABIBB_CONTROL_ENABLE BIT(7) #define REG_LABIBB_PD_CTL 0x47 #define LAB_PD_CTL_MASK GENMASK(1, 0) @@ -56,6 +67,11 @@ #define LAB_ENABLE_TIME (LABIBB_OFF_ON_DELAY * 2) #define IBB_ENABLE_TIME (LABIBB_OFF_ON_DELAY * 10) #define LABIBB_POLL_ENABLED_TIME 1000 +#define OCP_RECOVERY_INTERVAL_MS 500 +#define SC_RECOVERY_INTERVAL_MS 250 +#define LABIBB_MAX_OCP_COUNT 4 +#define LABIBB_MAX_SC_COUNT 3 +#define LABIBB_MAX_FATAL_COUNT 2 struct labibb_current_limits { u32 uA_min; @@ -69,10 +85,17 @@ struct labibb_regulator { struct regmap *regmap; struct regulator_dev *rdev; struct labibb_current_limits uA_limits; + struct delayed_work ocp_recovery_work; + struct delayed_work sc_recovery_work; u16 base; u8 type; u8 dischg_sel; u8 soft_start_sel; + int sc_irq; + int sc_count; + int ocp_irq; + int ocp_irq_count; + int fatal_count; }; struct labibb_regulator_data { @@ -82,6 +105,450 @@ struct labibb_regulator_data { const struct regulator_desc *desc; }; +static int qcom_labibb_ocp_hw_enable(struct regulator_dev *rdev) +{ + struct labibb_regulator *vreg = rdev_get_drvdata(rdev); + int ret; + + /* Clear irq latch status to avoid spurious event */ + ret = regmap_update_bits(rdev->regmap, + vreg->base + REG_LABIBB_INT_LATCHED_CLR, + LABIBB_INT_VREG_OK, 1); + if (ret) + return ret; + + /* Enable OCP HW interrupt */ + return regmap_update_bits(rdev->regmap, + vreg->base + REG_LABIBB_INT_EN_SET, + LABIBB_INT_VREG_OK, 1); +} + +static int qcom_labibb_ocp_hw_disable(struct regulator_dev *rdev) +{ + struct labibb_regulator *vreg = rdev_get_drvdata(rdev); + + return regmap_update_bits(rdev->regmap, + vreg->base + REG_LABIBB_INT_EN_CLR, + LABIBB_INT_VREG_OK, 1); +} + +/** + * qcom_labibb_check_ocp_status - Check the Over-Current Protection status + * @vreg: Main driver structure + * + * This function checks the STATUS1 register for the VREG_OK bit: if it is + * set, then there is no Over-Current event. + * + * Returns: Zero if there is no over-current, 1 if in over-current or + * negative number for error + */ +static int qcom_labibb_check_ocp_status(struct labibb_regulator *vreg) +{ + u32 cur_status; + int ret; + + ret = regmap_read(vreg->rdev->regmap, vreg->base + REG_LABIBB_STATUS1, + &cur_status); + if (ret) + return ret; + + return !(cur_status & LABIBB_STATUS1_VREG_OK_BIT); +} + +/** + * qcom_labibb_ocp_recovery_worker - Handle OCP event + * @work: OCP work structure + * + * This is the worker function to handle the Over Current Protection + * hardware event; This will check if the hardware is still + * signaling an over-current condition and will eventually stop + * the regulator if such condition is still signaled after + * LABIBB_MAX_OCP_COUNT times. + * + * If the driver that is consuming the regulator did not take action + * for the OCP condition, or the hardware did not stabilize, a cut + * of the LAB and IBB regulators will be forced (regulators will be + * disabled). + * + * As last, if the writes to shut down the LAB/IBB regulators fail + * for more than LABIBB_MAX_FATAL_COUNT, then a kernel panic will be + * triggered, as a last resort to protect the hardware from burning; + * this, however, is expected to never happen, but this is kept to + * try to further ensure that we protect the hardware at all costs. + */ +static void qcom_labibb_ocp_recovery_worker(struct work_struct *work) +{ + struct labibb_regulator *vreg; + const struct regulator_ops *ops; + int ret; + + vreg = container_of(work, struct labibb_regulator, + ocp_recovery_work.work); + ops = vreg->rdev->desc->ops; + + if (vreg->ocp_irq_count >= LABIBB_MAX_OCP_COUNT) { + /* + * If we tried to disable the regulator multiple times but + * we kept failing, there's only one last hope to save our + * hardware from the death: raise a kernel bug, reboot and + * hope that the bootloader kindly saves us. This, though + * is done only as paranoid checking, because failing the + * regmap write to disable the vreg is almost impossible, + * since we got here after multiple regmap R/W. + */ + BUG_ON(vreg->fatal_count > LABIBB_MAX_FATAL_COUNT); + dev_err(&vreg->rdev->dev, "LABIBB: CRITICAL: Disabling regulator\n"); + + /* Disable the regulator immediately to avoid damage */ + ret = ops->disable(vreg->rdev); + if (ret) { + vreg->fatal_count++; + goto reschedule; + } + enable_irq(vreg->ocp_irq); + vreg->fatal_count = 0; + return; + } + + ret = qcom_labibb_check_ocp_status(vreg); + if (ret != 0) { + vreg->ocp_irq_count++; + goto reschedule; + } + + ret = qcom_labibb_ocp_hw_enable(vreg->rdev); + if (ret) { + /* We cannot trust it without OCP enabled. */ + dev_err(vreg->dev, "Cannot enable OCP IRQ\n"); + vreg->ocp_irq_count++; + goto reschedule; + } + + enable_irq(vreg->ocp_irq); + /* Everything went fine: reset the OCP count! */ + vreg->ocp_irq_count = 0; + return; + +reschedule: + mod_delayed_work(system_wq, &vreg->ocp_recovery_work, + msecs_to_jiffies(OCP_RECOVERY_INTERVAL_MS)); +} + +/** + * qcom_labibb_ocp_isr - Interrupt routine for OverCurrent Protection + * @irq: Interrupt number + * @chip: Main driver structure + * + * Over Current Protection (OCP) will signal to the client driver + * that an over-current event has happened and then will schedule + * a recovery worker. + * + * Disabling and eventually re-enabling the regulator is expected + * to be done by the driver, as some hardware may be triggering an + * over-current condition only at first initialization or it may + * be expected only for a very brief amount of time, after which + * the attached hardware may be expected to stabilize its current + * draw. + * + * Returns: IRQ_HANDLED for success or IRQ_NONE for failure. + */ +static irqreturn_t qcom_labibb_ocp_isr(int irq, void *chip) +{ + struct labibb_regulator *vreg = chip; + const struct regulator_ops *ops = vreg->rdev->desc->ops; + int ret; + + /* If the regulator is not enabled, this is a fake event */ + if (!ops->is_enabled(vreg->rdev)) + return 0; + + /* If we tried to recover for too many times it's not getting better */ + if (vreg->ocp_irq_count > LABIBB_MAX_OCP_COUNT) + return IRQ_NONE; + + /* + * If we (unlikely) can't read this register, to prevent hardware + * damage at all costs, we assume that the overcurrent event was + * real; Moreover, if the status register is not signaling OCP, + * it was a spurious event, so it's all ok. + */ + ret = qcom_labibb_check_ocp_status(vreg); + if (ret == 0) { + vreg->ocp_irq_count = 0; + goto end; + } + vreg->ocp_irq_count++; + + /* + * Disable the interrupt temporarily, or it will fire continuously; + * we will re-enable it in the recovery worker function. + */ + disable_irq(irq); + + /* Warn the user for overcurrent */ + dev_warn(vreg->dev, "Over-Current interrupt fired!\n"); + + /* Disable the interrupt to avoid hogging */ + ret = qcom_labibb_ocp_hw_disable(vreg->rdev); + if (ret) + goto end; + + /* Signal overcurrent event to drivers */ + regulator_notifier_call_chain(vreg->rdev, + REGULATOR_EVENT_OVER_CURRENT, NULL); + +end: + /* Schedule the recovery work */ + schedule_delayed_work(&vreg->ocp_recovery_work, + msecs_to_jiffies(OCP_RECOVERY_INTERVAL_MS)); + if (ret) + return IRQ_NONE; + + return IRQ_HANDLED; +} + +static int qcom_labibb_set_ocp(struct regulator_dev *rdev) +{ + struct labibb_regulator *vreg = rdev_get_drvdata(rdev); + char *ocp_irq_name; + u32 irq_flags = IRQF_ONESHOT; + int irq_trig_low, ret; + + /* If there is no OCP interrupt, there's nothing to set */ + if (vreg->ocp_irq <= 0) + return -EINVAL; + + ocp_irq_name = devm_kasprintf(vreg->dev, GFP_KERNEL, "%s-over-current", + vreg->desc.name); + if (!ocp_irq_name) + return -ENOMEM; + + /* IRQ polarities - LAB: trigger-low, IBB: trigger-high */ + switch (vreg->type) { + case QCOM_LAB_TYPE: + irq_flags |= IRQF_TRIGGER_LOW; + irq_trig_low = 1; + break; + case QCOM_IBB_TYPE: + irq_flags |= IRQF_TRIGGER_HIGH; + irq_trig_low = 0; + break; + default: + return -EINVAL; + } + + /* Activate OCP HW level interrupt */ + ret = regmap_update_bits(rdev->regmap, + vreg->base + REG_LABIBB_INT_SET_TYPE, + LABIBB_INT_VREG_OK, + LABIBB_INT_VREG_TYPE_LEVEL); + if (ret) + return ret; + + /* Set OCP interrupt polarity */ + ret = regmap_update_bits(rdev->regmap, + vreg->base + REG_LABIBB_INT_POLARITY_HIGH, + LABIBB_INT_VREG_OK, !irq_trig_low); + if (ret) + return ret; + ret = regmap_update_bits(rdev->regmap, + vreg->base + REG_LABIBB_INT_POLARITY_LOW, + LABIBB_INT_VREG_OK, irq_trig_low); + if (ret) + return ret; + + ret = qcom_labibb_ocp_hw_enable(rdev); + if (ret) + return ret; + + return devm_request_threaded_irq(vreg->dev, vreg->ocp_irq, NULL, + qcom_labibb_ocp_isr, irq_flags, + ocp_irq_name, vreg); +} + +/** + * qcom_labibb_check_sc_status - Check the Short Circuit Protection status + * @vreg: Main driver structure + * + * This function checks the STATUS1 register on both LAB and IBB regulators + * for the ShortCircuit bit: if it is set on *any* of them, then we have + * experienced a short-circuit event. + * + * Returns: Zero if there is no short-circuit, 1 if in short-circuit or + * negative number for error + */ +static int qcom_labibb_check_sc_status(struct labibb_regulator *vreg) +{ + u32 ibb_status, ibb_reg, lab_status, lab_reg; + int ret; + + /* We have to work on both regulators due to PBS... */ + lab_reg = ibb_reg = vreg->base + REG_LABIBB_STATUS1; + if (vreg->type == QCOM_LAB_TYPE) + ibb_reg -= PMI8998_IBB_LAB_REG_OFFSET; + else + lab_reg += PMI8998_IBB_LAB_REG_OFFSET; + + ret = regmap_read(vreg->rdev->regmap, lab_reg, &lab_status); + if (ret) + return ret; + ret = regmap_read(vreg->rdev->regmap, ibb_reg, &ibb_status); + if (ret) + return ret; + + return !!(lab_status & LABIBB_STATUS1_SC_BIT) || + !!(ibb_status & LABIBB_STATUS1_SC_BIT); +} + +/** + * qcom_labibb_sc_recovery_worker - Handle Short Circuit event + * @work: SC work structure + * + * This is the worker function to handle the Short Circuit Protection + * hardware event; This will check if the hardware is still + * signaling a short-circuit condition and will eventually never + * re-enable the regulator if such condition is still signaled after + * LABIBB_MAX_SC_COUNT times. + * + * If the driver that is consuming the regulator did not take action + * for the SC condition, or the hardware did not stabilize, this + * worker will stop rescheduling, leaving the regulators disabled + * as already done by the Portable Batch System (PBS). + * + * Returns: IRQ_HANDLED for success or IRQ_NONE for failure. + */ +static void qcom_labibb_sc_recovery_worker(struct work_struct *work) +{ + struct labibb_regulator *vreg; + const struct regulator_ops *ops; + u32 lab_reg, ibb_reg, lab_val, ibb_val, val; + bool pbs_cut = false; + int i, sc, ret; + + vreg = container_of(work, struct labibb_regulator, + sc_recovery_work.work); + ops = vreg->rdev->desc->ops; + + /* + * If we tried to check the regulator status multiple times but we + * kept failing, then just bail out, as the Portable Batch System + * (PBS) will disable the vregs for us, preventing hardware damage. + */ + if (vreg->fatal_count > LABIBB_MAX_FATAL_COUNT) + return; + + /* Too many short-circuit events. Throw in the towel. */ + if (vreg->sc_count > LABIBB_MAX_SC_COUNT) + return; + + /* + * The Portable Batch System (PBS) automatically disables LAB + * and IBB when a short-circuit event is detected, so we have to + * check and work on both of them at the same time. + */ + lab_reg = ibb_reg = vreg->base + REG_LABIBB_ENABLE_CTL; + if (vreg->type == QCOM_LAB_TYPE) + ibb_reg -= PMI8998_IBB_LAB_REG_OFFSET; + else + lab_reg += PMI8998_IBB_LAB_REG_OFFSET; + + sc = qcom_labibb_check_sc_status(vreg); + if (sc) + goto reschedule; + + for (i = 0; i < LABIBB_MAX_SC_COUNT; i++) { + ret = regmap_read(vreg->regmap, lab_reg, &lab_val); + if (ret) { + vreg->fatal_count++; + goto reschedule; + } + + ret = regmap_read(vreg->regmap, ibb_reg, &ibb_val); + if (ret) { + vreg->fatal_count++; + goto reschedule; + } + val = lab_val & ibb_val; + + if (!(val & LABIBB_CONTROL_ENABLE)) { + pbs_cut = true; + break; + } + usleep_range(5000, 6000); + } + if (pbs_cut) + goto reschedule; + + + /* + * If we have reached this point, we either have successfully + * recovered from the SC condition or we had a spurious SC IRQ, + * which means that we can re-enable the regulators, if they + * have ever been disabled by the PBS. + */ + ret = ops->enable(vreg->rdev); + if (ret) + goto reschedule; + + /* Everything went fine: reset the OCP count! */ + vreg->sc_count = 0; + enable_irq(vreg->sc_irq); + return; + +reschedule: + /* + * Now that we have done basic handling of the short-circuit, + * reschedule this worker in the regular system workqueue, as + * taking action is not truly urgent anymore. + */ + vreg->sc_count++; + mod_delayed_work(system_wq, &vreg->sc_recovery_work, + msecs_to_jiffies(SC_RECOVERY_INTERVAL_MS)); +} + +/** + * qcom_labibb_sc_isr - Interrupt routine for Short Circuit Protection + * @irq: Interrupt number + * @chip: Main driver structure + * + * Short Circuit Protection (SCP) will signal to the client driver + * that a regulation-out event has happened and then will schedule + * a recovery worker. + * + * The LAB and IBB regulators will be automatically disabled by the + * Portable Batch System (PBS) and they will be enabled again by + * the worker function if the hardware stops signaling the short + * circuit event. + * + * Returns: IRQ_HANDLED for success or IRQ_NONE for failure. + */ +static irqreturn_t qcom_labibb_sc_isr(int irq, void *chip) +{ + struct labibb_regulator *vreg = chip; + + if (vreg->sc_count > LABIBB_MAX_SC_COUNT) + return IRQ_NONE; + + /* Warn the user for short circuit */ + dev_warn(vreg->dev, "Short-Circuit interrupt fired!\n"); + + /* + * Disable the interrupt temporarily, or it will fire continuously; + * we will re-enable it in the recovery worker function. + */ + disable_irq(irq); + + /* Signal out of regulation event to drivers */ + regulator_notifier_call_chain(vreg->rdev, + REGULATOR_EVENT_REGULATION_OUT, NULL); + + /* Schedule the short-circuit handling as high-priority work */ + mod_delayed_work(system_highpri_wq, &vreg->sc_recovery_work, + msecs_to_jiffies(SC_RECOVERY_INTERVAL_MS)); + return IRQ_HANDLED; +} + + static int qcom_labibb_set_current_limit(struct regulator_dev *rdev, int min_uA, int max_uA) { @@ -210,6 +677,7 @@ static const struct regulator_ops qcom_labibb_ops = { .set_current_limit = qcom_labibb_set_current_limit, .get_current_limit = qcom_labibb_get_current_limit, .set_soft_start = qcom_labibb_set_soft_start, + .set_over_current_protection = qcom_labibb_set_ocp, }; static const struct regulator_desc pmi8998_lab_desc = { @@ -287,7 +755,7 @@ static int qcom_labibb_regulator_probe(struct platform_device *pdev) struct labibb_regulator *vreg; struct device *dev = &pdev->dev; struct regulator_config cfg = {}; - + struct device_node *reg_node; const struct of_device_id *match; const struct labibb_regulator_data *reg_data; struct regmap *reg_regmap; @@ -305,6 +773,8 @@ static int qcom_labibb_regulator_probe(struct platform_device *pdev) return -ENODEV; for (reg_data = match->data; reg_data->name; reg_data++) { + char *sc_irq_name; + int irq = 0; /* Validate if the type of regulator is indeed * what's mentioned in DT. @@ -327,10 +797,44 @@ static int qcom_labibb_regulator_probe(struct platform_device *pdev) if (!vreg) return -ENOMEM; + sc_irq_name = devm_kasprintf(dev, GFP_KERNEL, + "%s-short-circuit", + reg_data->name); + if (!sc_irq_name) + return -ENOMEM; + + reg_node = of_get_child_by_name(pdev->dev.of_node, + reg_data->name); + if (!reg_node) + return -EINVAL; + + /* The Short Circuit interrupt is critical */ + irq = of_irq_get_byname(reg_node, "sc-err"); + if (irq <= 0) { + if (irq == 0) + irq = -EINVAL; + + return dev_err_probe(vreg->dev, irq, + "Short-circuit irq not found.\n"); + } + vreg->sc_irq = irq; + + /* OverCurrent Protection IRQ is optional */ + irq = of_irq_get_byname(reg_node, "ocp"); + vreg->ocp_irq = irq; + vreg->ocp_irq_count = 0; + of_node_put(reg_node); + vreg->regmap = reg_regmap; vreg->dev = dev; vreg->base = reg_data->base; vreg->type = reg_data->type; + INIT_DELAYED_WORK(&vreg->sc_recovery_work, + qcom_labibb_sc_recovery_worker); + + if (vreg->ocp_irq > 0) + INIT_DELAYED_WORK(&vreg->ocp_recovery_work, + qcom_labibb_ocp_recovery_worker); switch (vreg->type) { case QCOM_LAB_TYPE: @@ -365,6 +869,14 @@ static int qcom_labibb_regulator_probe(struct platform_device *pdev) reg_data->name, ret); return PTR_ERR(vreg->rdev); } + + ret = devm_request_threaded_irq(vreg->dev, vreg->sc_irq, NULL, + qcom_labibb_sc_isr, + IRQF_ONESHOT | + IRQF_TRIGGER_RISING, + sc_irq_name, vreg); + if (ret) + return ret; } return 0;