diff mbox series

[RFC,v3,4/7] regulator: add property parsing and callbacks to set protection limits

Message ID b949e8131ffd8775e46fc51d3a7558586a9a4be1.1615454845.git.matti.vaittinen@fi.rohmeurope.com (mailing list archive)
State Superseded
Headers show
Series Extend regulator notification support | expand

Commit Message

Vaittinen, Matti March 11, 2021, 10:23 a.m. UTC
Add DT property parsing code and setting callback for regulator over/under
voltage, over-current and temperature error limits.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
---
v3:
  - fix stpmic1_regulator compilation (Sorry again folks! This should never
    have slipped in v2)
v2:
  - convert spmi-regulator over-current protection
  - shorten DT property names as suggested by Rob

 drivers/regulator/core.c                  | 122 +++++++++++++++++++++-
 drivers/regulator/of_regulator.c          |  58 ++++++++++
 drivers/regulator/qcom-labibb-regulator.c |  10 +-
 drivers/regulator/qcom_spmi-regulator.c   |   6 +-
 drivers/regulator/stpmic1_regulator.c     |  20 +++-
 include/linux/regulator/driver.h          |  41 +++++++-
 include/linux/regulator/machine.h         |  26 +++++
 7 files changed, 274 insertions(+), 9 deletions(-)

Comments

Mark Brown April 2, 2021, 5:18 p.m. UTC | #1
On Thu, Mar 11, 2021 at 12:23:02PM +0200, Matti Vaittinen wrote:

> +	/*
> +	 * Existing logic does not warn if over_current_protection is given as
> +	 * a constraint but driver does not support that. I think we should
> +	 * warn about this type of issues as it is possible someone changes

The "existing logic" bit here is for a changelog, not the code - as soon
as the patch is applied the comment becomes inaccurate.  This also seems
like a separate patch.
Vaittinen, Matti April 4, 2021, 3:47 p.m. UTC | #2
Hi Mark,

Thanks for the review(s)!
On Fri, 2021-04-02 at 18:18 +0100, Mark Brown wrote:
> On Thu, Mar 11, 2021 at 12:23:02PM +0200, Matti Vaittinen wrote:
> 
> > +	/*
> > +	 * Existing logic does not warn if over_current_protection is
> > given as
> > +	 * a constraint but driver does not support that. I think we
> > should
> > +	 * warn about this type of issues as it is possible someone
> > changes
> 
> The "existing logic" bit here is for a changelog, not the code - as
> soon
> as the patch is applied the comment becomes inaccurate.  This also
> seems
> like a separate patch.

I don't think this patch changed the logic but kept it as it is now.
Eg, for the existing over_current_protection property we still silently
ignore case where property is given but driver does not support setting
it. For me this sounds like fragile approach and I did handle the new
properties (like detection) in a different way. Thus the comment should
stay valid - and thus I didn't think this warrants a new patch.

If you think we should change the logic, then we should definitely do
that in separate patch. That allows revert if existing setups break
everywhere. How would you like this to be? I can change the logic if
you see it's worth the risk of breaking existing setups.

Best Regards
	Matti Vaittinen
diff mbox series

Patch

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index fabc83288e1b..5a3b932dc8a5 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1312,6 +1312,52 @@  static int machine_constraints_current(struct regulator_dev *rdev,
 
 static int _regulator_do_enable(struct regulator_dev *rdev);
 
+static int notif_set_limit(struct regulator_dev *rdev,
+			   int (*set)(struct regulator_dev *, int, int, bool),
+			   int limit, int severity)
+{
+	bool enable;
+
+	if (limit == REGULATOR_NOTIF_LIMIT_DISABLE) {
+		enable = false;
+		limit = 0;
+	} else {
+		enable = true;
+	}
+
+	if (limit == REGULATOR_NOTIF_LIMIT_ENABLE)
+		limit = 0;
+
+	return set(rdev, limit, severity, enable);
+}
+
+static int handle_notify_limits(struct regulator_dev *rdev,
+			int (*set)(struct regulator_dev *, int, int, bool),
+			struct notification_limit *limits)
+{
+	int ret = 0;
+
+	if (!set)
+		return -EOPNOTSUPP;
+
+	if (limits->prot)
+		ret = notif_set_limit(rdev, set, limits->prot,
+				      REGULATOR_SEVERITY_PROT);
+	if (ret)
+		return ret;
+
+	if (limits->err)
+		ret = notif_set_limit(rdev, set, limits->err,
+				      REGULATOR_SEVERITY_ERR);
+	if (ret)
+		return ret;
+
+	if (limits->warn)
+		ret = notif_set_limit(rdev, set, limits->warn,
+				      REGULATOR_SEVERITY_WARN);
+
+	return ret;
+}
 /**
  * set_machine_constraints - sets regulator constraints
  * @rdev: regulator source
@@ -1397,9 +1443,27 @@  static int set_machine_constraints(struct regulator_dev *rdev)
 		}
 	}
 
+	/*
+	 * Existing logic does not warn if over_current_protection is given as
+	 * a constraint but driver does not support that. I think we should
+	 * warn about this type of issues as it is possible someone changes
+	 * PMIC on board to another type - and the another PMIC's driver does
+	 * not support setting protection. Board composer may happily believe
+	 * the DT limits are respected - especially if the new PMIC HW also
+	 * supports protection but the driver does not. I won't change the logic
+	 * without hearing more experienced opinion on this though.
+	 *
+	 * If warning is seen as a good idea then we can merge handling the
+	 * over-curret protection and detection and get rid of this special
+	 * handling.
+	 */
 	if (rdev->constraints->over_current_protection
 		&& ops->set_over_current_protection) {
-		ret = ops->set_over_current_protection(rdev);
+		int lim = rdev->constraints->over_curr_limits.prot;
+
+		ret = ops->set_over_current_protection(rdev, lim,
+						       REGULATOR_SEVERITY_PROT,
+						       true);
 		if (ret < 0) {
 			rdev_err(rdev, "failed to set over current protection: %pe\n",
 				 ERR_PTR(ret));
@@ -1407,6 +1471,62 @@  static int set_machine_constraints(struct regulator_dev *rdev)
 		}
 	}
 
+	if (rdev->constraints->over_current_detection)
+		ret = handle_notify_limits(rdev,
+					   ops->set_over_current_protection,
+					   &rdev->constraints->over_curr_limits);
+	if (ret) {
+		if (ret != -EOPNOTSUPP) {
+			rdev_err(rdev, "failed to set over current limits: %pe\n",
+				 ERR_PTR(ret));
+			return ret;
+		}
+		rdev_warn(rdev,
+			  "IC does not support requested over-current limits\n");
+	}
+
+	if (rdev->constraints->over_voltage_detection)
+		ret = handle_notify_limits(rdev,
+					   ops->set_over_voltage_protection,
+					   &rdev->constraints->over_voltage_limits);
+	if (ret) {
+		if (ret != -EOPNOTSUPP) {
+			rdev_err(rdev, "failed to set over voltage limits %pe\n",
+				 ERR_PTR(ret));
+			return ret;
+		}
+		rdev_warn(rdev,
+			  "IC does not support requested over voltage limits\n");
+	}
+
+	if (rdev->constraints->under_voltage_detection)
+		ret = handle_notify_limits(rdev,
+					   ops->set_under_voltage_protection,
+					   &rdev->constraints->under_voltage_limits);
+	if (ret) {
+		if (ret != -EOPNOTSUPP) {
+			rdev_err(rdev, "failed to set under voltage limits %pe\n",
+				 ERR_PTR(ret));
+			return ret;
+		}
+		rdev_warn(rdev,
+			  "IC does not support requested under voltage limits\n");
+	}
+
+	if (rdev->constraints->over_temp_detection)
+		ret = handle_notify_limits(rdev,
+					   ops->set_thermal_protection,
+					   &rdev->constraints->temp_limits);
+	if (ret) {
+		if (ret != -EOPNOTSUPP) {
+			rdev_err(rdev, "failed to set temperature limits %pe\n",
+				 ERR_PTR(ret));
+			return ret;
+		}
+		rdev_warn(rdev,
+			  "IC does not support requested temperature limits\n");
+	}
+
 	if (rdev->constraints->active_discharge && ops->set_active_discharge) {
 		bool ad_state = (rdev->constraints->active_discharge ==
 			      REGULATOR_ACTIVE_DISCHARGE_ENABLE) ? true : false;
diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c
index 564f928eb1db..b70fdc5c7000 100644
--- a/drivers/regulator/of_regulator.c
+++ b/drivers/regulator/of_regulator.c
@@ -21,6 +21,62 @@  static const char *const regulator_states[PM_SUSPEND_MAX + 1] = {
 	[PM_SUSPEND_MAX]	= "regulator-state-disk",
 };
 
+static void fill_limit(int *limit, int val)
+{
+	if (val)
+		if (val == 1)
+			*limit = REGULATOR_NOTIF_LIMIT_ENABLE;
+		else
+			*limit = val;
+	else
+		*limit = REGULATOR_NOTIF_LIMIT_DISABLE;
+}
+
+static void of_get_regulator_prot_limits(struct device_node *np,
+				struct regulation_constraints *constraints)
+{
+	u32 pval;
+	int i;
+	static const char *const props[] = {
+		"regulator-oc-%s-microamp",
+		"regulator-ov-%s-microvolt",
+		"regulator-temp-%s-kelvin",
+		"regulator-uv-%s-microvolt",
+	};
+	struct notification_limit *limits[] = {
+		&constraints->over_curr_limits,
+		&constraints->over_voltage_limits,
+		&constraints->temp_limits,
+		&constraints->under_voltage_limits,
+	};
+	bool set[4] = {0};
+
+	/* Protection limits: */
+	for (i = 0; i < ARRAY_SIZE(props); i++) {
+		char prop[255];
+		bool found;
+		int j;
+		static const char *const lvl[] = {
+			"protection", "error", "warn"
+		};
+		int *l[] = {
+			&limits[i]->prot, &limits[i]->err, &limits[i]->warn,
+		};
+
+		for (j = 0; j < ARRAY_SIZE(lvl); j++) {
+			snprintf(prop, 255, props[i], lvl[j]);
+			found = !of_property_read_u32(np, prop, &pval);
+			if (found)
+				fill_limit(l[j], pval);
+			set[i] |= found;
+		}
+	}
+	constraints->over_current_detection = set[0];
+	constraints->over_voltage_detection = set[1];
+	constraints->over_temp_detection = set[2];
+	constraints->under_voltage_detection = set[3];
+}
+
 static int of_get_regulation_constraints(struct device *dev,
 					struct device_node *np,
 					struct regulator_init_data **init_data,
@@ -188,6 +244,8 @@  static int of_get_regulation_constraints(struct device *dev,
 	constraints->over_current_protection = of_property_read_bool(np,
 					"regulator-over-current-protection");
 
+	of_get_regulator_prot_limits(np, constraints);
+
 	for (i = 0; i < ARRAY_SIZE(regulator_states); i++) {
 		switch (i) {
 		case PM_SUSPEND_MEM:
diff --git a/drivers/regulator/qcom-labibb-regulator.c b/drivers/regulator/qcom-labibb-regulator.c
index de25e3279b4b..b3da0dc58782 100644
--- a/drivers/regulator/qcom-labibb-regulator.c
+++ b/drivers/regulator/qcom-labibb-regulator.c
@@ -307,13 +307,21 @@  static irqreturn_t qcom_labibb_ocp_isr(int irq, void *chip)
 	return IRQ_HANDLED;
 }
 
-static int qcom_labibb_set_ocp(struct regulator_dev *rdev)
+static int qcom_labibb_set_ocp(struct regulator_dev *rdev, int lim,
+			       int severity, bool enable)
 {
 	struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
 	char *ocp_irq_name;
 	u32 irq_flags = IRQF_ONESHOT;
 	int irq_trig_low, ret;
 
+	/*
+	 * labibb supports only protection - and does not support setting
+	 * limit. Furthermore, we don't support disabling protection.
+	 */
+	if (lim || severity != REGULATOR_SEVERITY_PROT || !enable)
+		return -EINVAL;
+
 	/* If there is no OCP interrupt, there's nothing to set */
 	if (vreg->ocp_irq <= 0)
 		return -EINVAL;
diff --git a/drivers/regulator/qcom_spmi-regulator.c b/drivers/regulator/qcom_spmi-regulator.c
index e62e1d72d943..45b29c8856bd 100644
--- a/drivers/regulator/qcom_spmi-regulator.c
+++ b/drivers/regulator/qcom_spmi-regulator.c
@@ -594,11 +594,15 @@  static int spmi_regulator_vs_enable(struct regulator_dev *rdev)
 	return regulator_enable_regmap(rdev);
 }
 
-static int spmi_regulator_vs_ocp(struct regulator_dev *rdev)
+static int spmi_regulator_vs_ocp(struct regulator_dev *rdev, int lim_uA,
+				 int severity, bool enable)
 {
 	struct spmi_regulator *vreg = rdev_get_drvdata(rdev);
 	u8 reg = SPMI_VS_OCP_OVERRIDE;
 
+	if (lim_uA || !enable || severity != REGULATOR_SEVERITY_PROT)
+		return -EINVAL;
+
 	return spmi_vreg_write(vreg, SPMI_VS_REG_OCP, &reg, 1);
 }
 
diff --git a/drivers/regulator/stpmic1_regulator.c b/drivers/regulator/stpmic1_regulator.c
index cf10fdb72e32..2d7597c76e4a 100644
--- a/drivers/regulator/stpmic1_regulator.c
+++ b/drivers/regulator/stpmic1_regulator.c
@@ -32,7 +32,8 @@  struct stpmic1_regulator_cfg {
 
 static int stpmic1_set_mode(struct regulator_dev *rdev, unsigned int mode);
 static unsigned int stpmic1_get_mode(struct regulator_dev *rdev);
-static int stpmic1_set_icc(struct regulator_dev *rdev);
+static int stpmic1_set_icc(struct regulator_dev *rdev, int lim, int severity,
+			   bool enable);
 static unsigned int stpmic1_map_mode(unsigned int mode);
 
 enum {
@@ -491,11 +492,26 @@  static int stpmic1_set_mode(struct regulator_dev *rdev, unsigned int mode)
 				  STPMIC1_BUCK_MODE_LP, value);
 }
 
-static int stpmic1_set_icc(struct regulator_dev *rdev)
+static int stpmic1_set_icc(struct regulator_dev *rdev, int lim, int severity,
+			   bool enable)
 {
 	struct stpmic1_regulator_cfg *cfg = rdev_get_drvdata(rdev);
 	struct regmap *regmap = rdev_get_regmap(rdev);
 
+	/*
+	 * The code seems like one bit in a register controls whether OCP is
+	 * enabled. So we might be able to turn it off here is if that
+	 * was requested. I won't support this because I don't have the HW.
+	 * Feel free to try and implement if you have the HW and need kernel
+	 * to disable this.
+	 *
+	 * Also, I don't know if limit can be configured or if we support
+	 * error/warning instead of protect. So I just keep existing logic
+	 * and assume no.
+	 */
+	if (lim || severity != REGULATOR_SEVERITY_PROT || !enable)
+		return -EINVAL;
+
 	/* enable switch off in case of over current */
 	return regmap_update_bits(regmap, cfg->icc_reg, cfg->icc_mask,
 				  cfg->icc_mask);
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index ff0c492786fd..6d56e7cdecf8 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -40,6 +40,15 @@  enum regulator_status {
 	REGULATOR_STATUS_UNDEFINED,
 };
 
+enum regulator_detection_severity {
+	/* Hardware shut down voltage outputs if condition is detected */
+	REGULATOR_SEVERITY_PROT,
+	/* Hardware is probably damaged/inoperable */
+	REGULATOR_SEVERITY_ERR,
+	/* Hardware is still recoverable but recovery action must be taken */
+	REGULATOR_SEVERITY_WARN,
+};
+
 /* Initialize struct linear_range for regulators */
 #define REGULATOR_LINEAR_RANGE(_min_uV, _min_sel, _max_sel, _step_uV)	\
 {									\
@@ -78,8 +87,25 @@  enum regulator_status {
  * @get_current_limit: Get the configured limit for a current-limited regulator.
  * @set_input_current_limit: Configure an input limit.
  *
- * @set_over_current_protection: Support capability of automatically shutting
- *                               down when detecting an over current event.
+ * @set_over_current_protection: Support enabling of and setting limits for over
+ *	current situation detection. Detection can be configured for three
+ *	levels of severity.
+ *	REGULATOR_SEVERITY_PROT should automatically shut down the regulator(s).
+ *	REGULATOR_SEVERITY_ERR should indicate that over-current situation is
+ *		caused by an unrecoverable error but HW does not perform
+ *		automatic shut down.
+ *	REGULATOR_SEVERITY_WARN should indicate situation where hardware is
+ *		still believed to not be damaged but that a board sepcific
+ *		recovery action is needed. If lim_uA is 0 the limit should not
+ *		be changed but the detection should just be enabled/disabled as
+ *		is requested.
+ * @set_over_voltage_protection: Support enabling of and setting limits for over
+ *	voltage situation detection. Detection can be configured for same
+ *	severities as over current protection.
+ * @set_under_voltage_protection: Support enabling of and setting limits for
+ *	under situation detection.
+ * @set_thermal_protection: Support enabling of and setting limits for over
+ *	temperature situation detection.
  *
  * @set_active_discharge: Set active discharge enable/disable of regulators.
  *
@@ -143,8 +169,15 @@  struct regulator_ops {
 	int (*get_current_limit) (struct regulator_dev *);
 
 	int (*set_input_current_limit) (struct regulator_dev *, int lim_uA);
-	int (*set_over_current_protection) (struct regulator_dev *);
-	int (*set_active_discharge) (struct regulator_dev *, bool enable);
+	int (*set_over_current_protection)(struct regulator_dev *, int lim_uA,
+					   int severity, bool enable);
+	int (*set_over_voltage_protection)(struct regulator_dev *, int lim_uV,
+					   int severity, bool enable);
+	int (*set_under_voltage_protection)(struct regulator_dev *, int lim_uV,
+					    int severity, bool enable);
+	int (*set_thermal_protection)(struct regulator_dev *, int lim,
+				      int severity, bool enable);
+	int (*set_active_discharge)(struct regulator_dev *, bool enable);
 
 	/* enable/disable regulator */
 	int (*enable) (struct regulator_dev *);
diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h
index 8a56f033b6cd..68b4a514a410 100644
--- a/include/linux/regulator/machine.h
+++ b/include/linux/regulator/machine.h
@@ -83,6 +83,14 @@  struct regulator_state {
 	bool changeable;
 };
 
+#define REGULATOR_NOTIF_LIMIT_DISABLE -1
+#define REGULATOR_NOTIF_LIMIT_ENABLE -2
+struct notification_limit {
+	int prot;
+	int err;
+	int warn;
+};
+
 /**
  * struct regulation_constraints - regulator operating constraints.
  *
@@ -100,6 +108,11 @@  struct regulator_state {
  * @ilim_uA: Maximum input current.
  * @system_load: Load that isn't captured by any consumer requests.
  *
+ * @over_curr_limits:		Limits for acting on over current.
+ * @over_voltage_limits:	Limits for acting on over voltage.
+ * @under_voltage_limits:	Limits for acting on under voltage.
+ * @temp_limits:		Limits for acting on over temperature.
+
  * @max_spread: Max possible spread between coupled regulators
  * @max_uV_step: Max possible step change in voltage
  * @valid_modes_mask: Mask of modes which may be configured by consumers.
@@ -116,6 +129,11 @@  struct regulator_state {
  * @pull_down: Enable pull down when regulator is disabled.
  * @over_current_protection: Auto disable on over current event.
  *
+ * @over_current_detection: Configure over current limits.
+ * @over_voltage_detection: Configure over voltage limits.
+ * @under_voltage_detection: Configure under voltage limits.
+ * @over_temp_detection: Configure over temperature limits.
+ *
  * @input_uV: Input voltage for regulator when supplied by another regulator.
  *
  * @state_disk: State for regulator when system is suspended in disk mode.
@@ -172,6 +190,10 @@  struct regulation_constraints {
 	struct regulator_state state_disk;
 	struct regulator_state state_mem;
 	struct regulator_state state_standby;
+	struct notification_limit over_curr_limits;
+	struct notification_limit over_voltage_limits;
+	struct notification_limit under_voltage_limits;
+	struct notification_limit temp_limits;
 	suspend_state_t initial_state; /* suspend state to set at init */
 
 	/* mode to set on startup */
@@ -193,6 +215,10 @@  struct regulation_constraints {
 	unsigned soft_start:1;	/* ramp voltage slowly */
 	unsigned pull_down:1;	/* pull down resistor when regulator off */
 	unsigned over_current_protection:1; /* auto disable on over current */
+	unsigned over_current_detection:1; /* notify on over current */
+	unsigned over_voltage_detection:1; /* notify on over voltage */
+	unsigned under_voltage_detection:1; /* notify on under voltage */
+	unsigned over_temp_detection:1; /* notify on over temperature */
 };
 
 /**