[PATCH v9 06/10] regulator: add property parsing and callbacks to set protection limits

From: Matti Vaittinen
Date: Mon May 10 2021 - 08:50:41 EST

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@xxxxxxxxxxxxxxxxx>
---
No changes since RFC-v3
---
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(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 87f53f5fbbd0..e40cb8c338dc 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1315,6 +1315,52 @@ 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
@@ -1400,9 +1446,27 @@ 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));
@@ -1410,6 +1474,62 @@ 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 49f6c05fee34..f54d4f176882 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 95677c51c1fa..41424a3366d0 100644
--- a/drivers/regulator/qcom_spmi-regulator.c
+++ b/drivers/regulator/qcom_spmi-regulator.c
@@ -595,11 +595,15 @@ 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 be301b28838a..eb979b810639 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 */
};

/**
--
2.25.4


--
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]

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