[PATCH v4 0/4] Extend pm8941-pwrkey driver

[PATCH v4 0/4] Extend pm8941-pwrkey driver

[Anjelique Melendez]

Changes from v3:
  - Fixed dereference issue in 2/4
  - Added Stephen's reviewed by tag for 2/4

Changes from v2:
  - Addressed Stephen's comments
    - Add Stephen's reviewed by tag for 1/4
    - Fixed style for 2/4
    - Corrected function call to use correct function for 3/4

Changes from v1:
  - Removed Change-Id from all patches
  - Updated subject line of cover letter
  - Addressed Stephen's comments for v1 1/3
    - Separated error message fix to own patch (v2 1/4)
    - Separated PON GEN3 base address changes to own patch (v2 2/4)
    - Added new variables and functions to make code more readable
  - Removed v1 3/3 as per Bjorn's comments

Anjelique Melendez (2):
  input: misc: pm8941-pwrkey: fix error message
  input: misc: pm8941-pwrkey: add support for PON GEN3 base addresses

David Collins (2):
  input: misc: pm8941-pwrkey: add software key press debouncing support
  input: misc: pm8941-pwrkey: simulate missed key press events

 drivers/input/misc/pm8941-pwrkey.c | 124 +++++++++++++++++++++++++----
 1 file changed, 110 insertions(+), 14 deletions(-)

-- 
2.34.1

[PATCH v4 1/4] input: misc: pm8941-pwrkey: fix error message

[Anjelique Melendez]

Currently, error message reads "failed to set debounce". However,
code is attempting to read revision not set debounce. Fix this.

Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Anjelique Melendez <quic_amelende@quicinc.com>
---
 drivers/input/misc/pm8941-pwrkey.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/misc/pm8941-pwrkey.c b/drivers/input/misc/pm8941-pwrkey.c
index 33609603245d..e0240db12d4f 100644
--- a/drivers/input/misc/pm8941-pwrkey.c
+++ b/drivers/input/misc/pm8941-pwrkey.c
@@ -217,7 +217,7 @@ static int pm8941_pwrkey_probe(struct platform_device *pdev)
 	error = regmap_read(pwrkey->regmap, pwrkey->baseaddr + PON_REV2,
 			    &pwrkey->revision);
 	if (error) {
-		dev_err(&pdev->dev, "failed to set debounce: %d\n", error);
+		dev_err(&pdev->dev, "failed to read revision: %d\n", error);
 		return error;
 	}
 
-- 
2.34.1

[PATCH v4 2/4] input: misc: pm8941-pwrkey: add support for PON GEN3 base addresses

[Anjelique Melendez]

Currently, PON address is read from the "reg" property. For PON GEN3,
which starts with PMK8350, the "reg" property will have both the PON
HLOS and PON PBS addesses defined. Add support so that all PON
generations can be configured.

Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Anjelique Melendez <quic_amelende@quicinc.com>
---
 drivers/input/misc/pm8941-pwrkey.c | 31 +++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/drivers/input/misc/pm8941-pwrkey.c b/drivers/input/misc/pm8941-pwrkey.c
index e0240db12d4f..43106e4cfd23 100644
--- a/drivers/input/misc/pm8941-pwrkey.c
+++ b/drivers/input/misc/pm8941-pwrkey.c
@@ -12,6 +12,7 @@
 #include <linux/log2.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/reboot.h>
@@ -44,6 +45,7 @@ struct pm8941_data {
 	unsigned int	status_bit;
 	bool		supports_ps_hold_poff_config;
 	bool		supports_debounce_config;
+	bool		has_pon_pbs;
 	const char	*name;
 	const char	*phys;
 };
@@ -52,6 +54,7 @@ struct pm8941_pwrkey {
 	struct device *dev;
 	int irq;
 	u32 baseaddr;
+	u32 pon_pbs_baseaddr;
 	struct regmap *regmap;
 	struct input_dev *input;
 
@@ -167,6 +170,8 @@ static int pm8941_pwrkey_probe(struct platform_device *pdev)
 	struct pm8941_pwrkey *pwrkey;
 	bool pull_up;
 	struct device *parent;
+	struct device_node *regmap_node;
+	const __be32 *addr;
 	u32 req_delay;
 	int error;
 
@@ -188,8 +193,10 @@ static int pm8941_pwrkey_probe(struct platform_device *pdev)
 	pwrkey->data = of_device_get_match_data(&pdev->dev);
 
 	parent = pdev->dev.parent;
+	regmap_node = pdev->dev.of_node;
 	pwrkey->regmap = dev_get_regmap(parent, NULL);
 	if (!pwrkey->regmap) {
+		regmap_node = parent->of_node;
 		/*
 		 * We failed to get regmap for parent. Let's see if we are
 		 * a child of pon node and read regmap and reg from its
@@ -200,15 +207,21 @@ static int pm8941_pwrkey_probe(struct platform_device *pdev)
 			dev_err(&pdev->dev, "failed to locate regmap\n");
 			return -ENODEV;
 		}
+	}
 
-		error = of_property_read_u32(parent->of_node,
-					     "reg", &pwrkey->baseaddr);
-	} else {
-		error = of_property_read_u32(pdev->dev.of_node, "reg",
-					     &pwrkey->baseaddr);
+	addr = of_get_address(regmap_node, 0, NULL, NULL);
+	if (!addr) {
+		dev_err(&pdev->dev, "reg property missing\n");
+		return -EINVAL;
+	}
+	pwrkey->baseaddr = be32_to_cpup(addr);
+
+	if (pwrkey->data->has_pon_pbs) {
+		/* PON_PBS base address is optional */
+		addr = of_get_address(regmap_node, 1, NULL, NULL);
+		if (addr)
+			pwrkey->pon_pbs_baseaddr = be32_to_cpup(addr);
 	}
-	if (error)
-		return error;
 
 	pwrkey->irq = platform_get_irq(pdev, 0);
 	if (pwrkey->irq < 0)
@@ -316,6 +329,7 @@ static const struct pm8941_data pwrkey_data = {
 	.phys = "pm8941_pwrkey/input0",
 	.supports_ps_hold_poff_config = true,
 	.supports_debounce_config = true,
+	.has_pon_pbs = false,
 };
 
 static const struct pm8941_data resin_data = {
@@ -325,6 +339,7 @@ static const struct pm8941_data resin_data = {
 	.phys = "pm8941_resin/input0",
 	.supports_ps_hold_poff_config = true,
 	.supports_debounce_config = true,
+	.has_pon_pbs = false,
 };
 
 static const struct pm8941_data pon_gen3_pwrkey_data = {
@@ -333,6 +348,7 @@ static const struct pm8941_data pon_gen3_pwrkey_data = {
 	.phys = "pmic_pwrkey/input0",
 	.supports_ps_hold_poff_config = false,
 	.supports_debounce_config = false,
+	.has_pon_pbs = true,
 };
 
 static const struct pm8941_data pon_gen3_resin_data = {
@@ -341,6 +357,7 @@ static const struct pm8941_data pon_gen3_resin_data = {
 	.phys = "pmic_resin/input0",
 	.supports_ps_hold_poff_config = false,
 	.supports_debounce_config = false,
+	.has_pon_pbs = true,
 };
 
 static const struct of_device_id pm8941_pwr_key_id_table[] = {
-- 
2.34.1

[PATCH v4 3/4] input: misc: pm8941-pwrkey: add software key press debouncing support

[Anjelique Melendez]

From: David Collins <collinsd@codeaurora.org>

On certain PMICs, an unexpected assertion of KPDPWR_DEB (the
positive logic hardware debounced power key signal) may be seen
during the falling edge of KPDPWR_N (i.e. a power key press) when
it occurs close to the rising edge of SLEEP_CLK.  This then
triggers a spurious KPDPWR interrupt.

Handle this issue by adding software debouncing support to ignore
key events that occur within the hardware debounce delay after the
most recent key release event.

Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Anjelique Melendez <quic_amelende@quicinc.com>
---
 drivers/input/misc/pm8941-pwrkey.c | 80 +++++++++++++++++++++++++++---
 1 file changed, 74 insertions(+), 6 deletions(-)

diff --git a/drivers/input/misc/pm8941-pwrkey.c b/drivers/input/misc/pm8941-pwrkey.c
index 43106e4cfd23..881943ab4d55 100644
--- a/drivers/input/misc/pm8941-pwrkey.c
+++ b/drivers/input/misc/pm8941-pwrkey.c
@@ -9,6 +9,7 @@
 #include <linux/input.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
+#include <linux/ktime.h>
 #include <linux/log2.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -20,6 +21,16 @@
 
 #define PON_REV2			0x01
 
+#define PON_SUBTYPE			0x05
+
+#define PON_SUBTYPE_PRIMARY		0x01
+#define PON_SUBTYPE_SECONDARY		0x02
+#define PON_SUBTYPE_1REG		0x03
+#define PON_SUBTYPE_GEN2_PRIMARY	0x04
+#define PON_SUBTYPE_GEN2_SECONDARY	0x05
+#define PON_SUBTYPE_GEN3_PBS		0x08
+#define PON_SUBTYPE_GEN3_HLOS		0x09
+
 #define PON_RT_STS			0x10
 #define  PON_KPDPWR_N_SET		BIT(0)
 #define  PON_RESIN_N_SET		BIT(1)
@@ -59,9 +70,12 @@ struct pm8941_pwrkey {
 	struct input_dev *input;
 
 	unsigned int revision;
+	unsigned int subtype;
 	struct notifier_block reboot_notifier;
 
 	u32 code;
+	u32 sw_debounce_time_us;
+	ktime_t sw_debounce_end_time;
 	const struct pm8941_data *data;
 };
 
@@ -128,20 +142,63 @@ static irqreturn_t pm8941_pwrkey_irq(int irq, void *_data)
 {
 	struct pm8941_pwrkey *pwrkey = _data;
 	unsigned int sts;
-	int error;
+	int err;
 
-	error = regmap_read(pwrkey->regmap,
-			    pwrkey->baseaddr + PON_RT_STS, &sts);
-	if (error)
+	if (pwrkey->sw_debounce_time_us) {
+		if (ktime_before(ktime_get(), pwrkey->sw_debounce_end_time)) {
+			dev_dbg(pwrkey->dev, "ignoring key event received before debounce end %llu us\n",
+				pwrkey->sw_debounce_end_time);
+			return IRQ_HANDLED;
+		}
+	}
+
+	err = regmap_read(pwrkey->regmap, pwrkey->baseaddr + PON_RT_STS, &sts);
+	if (err)
 		return IRQ_HANDLED;
 
-	input_report_key(pwrkey->input, pwrkey->code,
-			 sts & pwrkey->data->status_bit);
+	sts &= pwrkey->data->status_bit;
+
+	if (pwrkey->sw_debounce_time_us && !sts)
+		pwrkey->sw_debounce_end_time = ktime_add_us(ktime_get(),
+						pwrkey->sw_debounce_time_us);
+
+	input_report_key(pwrkey->input, pwrkey->code, sts);
 	input_sync(pwrkey->input);
 
 	return IRQ_HANDLED;
 }
 
+static int pm8941_pwrkey_sw_debounce_init(struct pm8941_pwrkey *pwrkey)
+{
+	unsigned int val, addr, mask;
+	int error;
+
+	if (pwrkey->data->has_pon_pbs && !pwrkey->pon_pbs_baseaddr) {
+		dev_err(pwrkey->dev, "PON_PBS address missing, can't read HW debounce time\n");
+		return 0;
+	}
+
+	if (pwrkey->pon_pbs_baseaddr)
+		addr = pwrkey->pon_pbs_baseaddr + PON_DBC_CTL;
+	else
+		addr = pwrkey->baseaddr + PON_DBC_CTL;
+	error = regmap_read(pwrkey->regmap, addr, &val);
+	if (error)
+		return error;
+
+	if (pwrkey->subtype >= PON_SUBTYPE_GEN2_PRIMARY)
+		mask = 0xf;
+	else
+		mask = 0x7;
+
+	pwrkey->sw_debounce_time_us = 2 * USEC_PER_SEC / (1 << (mask - (val & mask)));
+
+	dev_dbg(pwrkey->dev, "SW debounce time = %u us\n",
+		pwrkey->sw_debounce_time_us);
+
+	return 0;
+}
+
 static int __maybe_unused pm8941_pwrkey_suspend(struct device *dev)
 {
 	struct pm8941_pwrkey *pwrkey = dev_get_drvdata(dev);
@@ -234,6 +291,13 @@ static int pm8941_pwrkey_probe(struct platform_device *pdev)
 		return error;
 	}
 
+	error = regmap_read(pwrkey->regmap, pwrkey->baseaddr + PON_SUBTYPE,
+			    &pwrkey->subtype);
+	if (error) {
+		dev_err(&pdev->dev, "failed to read subtype: %d\n", error);
+		return error;
+	}
+
 	error = of_property_read_u32(pdev->dev.of_node, "linux,code",
 				     &pwrkey->code);
 	if (error) {
@@ -268,6 +332,10 @@ static int pm8941_pwrkey_probe(struct platform_device *pdev)
 		}
 	}
 
+	error = pm8941_pwrkey_sw_debounce_init(pwrkey);
+	if (error)
+		return error;
+
 	if (pwrkey->data->pull_up_bit) {
 		error = regmap_update_bits(pwrkey->regmap,
 					   pwrkey->baseaddr + PON_PULL_CTL,
-- 
2.34.1

[PATCH v4 4/4] input: misc: pm8941-pwrkey: simulate missed key press events

[Anjelique Melendez]

From: David Collins <collinsd@codeaurora.org>

The status of the keys connected to the KPDPWR_N and RESIN_N pins
is identified by reading corresponding bits in the interrupt real
time status register.  If the status has changed by the time that
the interrupt is handled then a press event will be missed.

Maintain a last known status variable to find unbalanced release
events and simulate press events for each accordingly.

Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Anjelique Melendez <quic_amelende@quicinc.com>
---
 drivers/input/misc/pm8941-pwrkey.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/input/misc/pm8941-pwrkey.c b/drivers/input/misc/pm8941-pwrkey.c
index 881943ab4d55..3519152759dd 100644
--- a/drivers/input/misc/pm8941-pwrkey.c
+++ b/drivers/input/misc/pm8941-pwrkey.c
@@ -76,6 +76,7 @@ struct pm8941_pwrkey {
 	u32 code;
 	u32 sw_debounce_time_us;
 	ktime_t sw_debounce_end_time;
+	bool last_status;
 	const struct pm8941_data *data;
 };
 
@@ -162,6 +163,16 @@ static irqreturn_t pm8941_pwrkey_irq(int irq, void *_data)
 		pwrkey->sw_debounce_end_time = ktime_add_us(ktime_get(),
 						pwrkey->sw_debounce_time_us);
 
+	/*
+	 * Simulate a press event in case a release event occurred without a
+	 * corresponding press event.
+	 */
+	if (!pwrkey->last_status && !sts) {
+		input_report_key(pwrkey->input, pwrkey->code, 1);
+		input_sync(pwrkey->input);
+	}
+	pwrkey->last_status = sts;
+
 	input_report_key(pwrkey->input, pwrkey->code, sts);
 	input_sync(pwrkey->input);
 
-- 
2.34.1