* [PATCH v10 3/3] usb: typec: maxim_contaminant: Implement check_contaminant callback
2022-12-10 18:51 [PATCH v10 1/3] usb: typec: tcpm: Add callbacks to mitigate wakeups due to contaminant Badhri Jagan Sridharan
2022-12-10 18:51 ` [PATCH v10 2/3] usb: typec: tcpci: Add callback for evaluating contaminant presence Badhri Jagan Sridharan
@ 2022-12-10 18:51 ` Badhri Jagan Sridharan
2022-12-10 19:09 ` [PATCH v10 1/3] usb: typec: tcpm: Add callbacks to mitigate wakeups due to contaminant Guenter Roeck
2 siblings, 0 replies; 5+ messages in thread
From: Badhri Jagan Sridharan @ 2022-12-10 18:51 UTC (permalink / raw)
To: Guenter Roeck, Heikki Krogerus, Greg Kroah-Hartman
Cc: linux-usb, linux-kernel, Kyle Tso, Badhri Jagan Sridharan
Maxim TCPC has additional ADCs and low current(1ua) current source
to measure the impedance of CC and SBU pins. When tcpm invokes
the check_contaminant callback, Maxim TCPC measures the impedance
of the CC & SBU pins and when the impedance measured is less than
1MOhm, it is assumed that USB-C port is contaminated. CC comparators
are also checked to differentiate between presence of sink and
contaminant. Once USB-C is deemed to be contaminated, MAXIM TCPC
has additional hardware to disable normal DRP toggling cycle and
enable 1ua on CC pins once every 2.4secs/4.8secs. Maxim TCPC
interrupts AP once the impedance on the CC pin is above the
1MOhm threshold. The Maxim tcpc driver then signals TCPM_PORT_CLEAN
to restart toggling.
Renaming tcpci_maxim.c to tcpci_maxim_core.c and moving reg read/write
helper functions to the tcpci_maxim.h header file.
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
---
Changes since v9:
* None.
Changes since V7:
* None. Skipped versions by mistake.
Changes since v6:
* Refactored logic for check_contaminant and removed
* is_potential_contaminant.
Changes since v5:
* None
Changes since v4:
* Missed committing local changes to fix ktest robot warnings.
Updated the patch in v5.
Changes since v3:
* Renamed functions and removed the unecessary EXPORT.
* Fixed ktest robot warning.
Changes since v2:
* Implemented is_potential_contaminant to offload
* disconnect_while_debouncing
Changes since v1:
* Renamed tcpci_maxim.c to tcpci_maxim_core.c and compiling
tcpci_maxim_core.o with maxim_contaminant.o as a single module
as suggested by Guenter Roeck
* Got rid of exporting symbols for reg read/write helper functions
and moved them to header as suggested by Heikki Krogerus
* Sqashed the commit which exposed the max_tcpci_read helper functions
into this one.
---
drivers/usb/typec/tcpm/Makefile | 1 +
drivers/usb/typec/tcpm/maxim_contaminant.c | 337 ++++++++++++++++++
drivers/usb/typec/tcpm/tcpci_maxim.h | 89 +++++
.../{tcpci_maxim.c => tcpci_maxim_core.c} | 53 ++-
4 files changed, 448 insertions(+), 32 deletions(-)
create mode 100644 drivers/usb/typec/tcpm/maxim_contaminant.c
create mode 100644 drivers/usb/typec/tcpm/tcpci_maxim.h
rename drivers/usb/typec/tcpm/{tcpci_maxim.c => tcpci_maxim_core.c} (93%)
diff --git a/drivers/usb/typec/tcpm/Makefile b/drivers/usb/typec/tcpm/Makefile
index 906d9dced8e7..08e57bb499cb 100644
--- a/drivers/usb/typec/tcpm/Makefile
+++ b/drivers/usb/typec/tcpm/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_TYPEC_RT1711H) += tcpci_rt1711h.o
obj-$(CONFIG_TYPEC_MT6360) += tcpci_mt6360.o
obj-$(CONFIG_TYPEC_TCPCI_MT6370) += tcpci_mt6370.o
obj-$(CONFIG_TYPEC_TCPCI_MAXIM) += tcpci_maxim.o
+tcpci_maxim-y += tcpci_maxim_core.o maxim_contaminant.o
diff --git a/drivers/usb/typec/tcpm/maxim_contaminant.c b/drivers/usb/typec/tcpm/maxim_contaminant.c
new file mode 100644
index 000000000000..23b5ed65cba8
--- /dev/null
+++ b/drivers/usb/typec/tcpm/maxim_contaminant.c
@@ -0,0 +1,337 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2022 Google, Inc
+ *
+ * USB-C module to reduce wakeups due to contaminants.
+ */
+
+#include <linux/device.h>
+#include <linux/irqreturn.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/usb/tcpci.h>
+#include <linux/usb/tcpm.h>
+#include <linux/usb/typec.h>
+
+#include "tcpci_maxim.h"
+
+enum fladc_select {
+ CC1_SCALE1 = 1,
+ CC1_SCALE2,
+ CC2_SCALE1,
+ CC2_SCALE2,
+ SBU1,
+ SBU2,
+};
+
+#define FLADC_1uA_LSB_MV 25
+/* High range CC */
+#define FLADC_CC_HIGH_RANGE_LSB_MV 208
+/* Low range CC */
+#define FLADC_CC_LOW_RANGE_LSB_MV 126
+
+/* 1uA current source */
+#define FLADC_CC_SCALE1 1
+/* 5 uA current source */
+#define FLADC_CC_SCALE2 5
+
+#define FLADC_1uA_CC_OFFSET_MV 300
+#define FLADC_CC_HIGH_RANGE_OFFSET_MV 624
+#define FLADC_CC_LOW_RANGE_OFFSET_MV 378
+
+#define CONTAMINANT_THRESHOLD_SBU_K 1000
+#define CONTAMINANT_THRESHOLD_CC_K 1000
+
+#define READ1_SLEEP_MS 10
+#define READ2_SLEEP_MS 5
+
+#define STATUS_CHECK(reg, mask, val) (((reg) & (mask)) == (val))
+
+#define IS_CC_OPEN(cc_status) \
+ (STATUS_CHECK((cc_status), TCPC_CC_STATUS_CC1_MASK << TCPC_CC_STATUS_CC1_SHIFT, \
+ TCPC_CC_STATE_SRC_OPEN) && STATUS_CHECK((cc_status), \
+ TCPC_CC_STATUS_CC2_MASK << \
+ TCPC_CC_STATUS_CC2_SHIFT, \
+ TCPC_CC_STATE_SRC_OPEN))
+
+static int max_contaminant_adc_to_mv(struct max_tcpci_chip *chip, enum fladc_select channel,
+ bool ua_src, u8 fladc)
+{
+ /* SBU channels only have 1 scale with 1uA. */
+ if ((ua_src && (channel == CC1_SCALE2 || channel == CC2_SCALE2 || channel == SBU1 ||
+ channel == SBU2)))
+ /* Mean of range */
+ return FLADC_1uA_CC_OFFSET_MV + (fladc * FLADC_1uA_LSB_MV);
+ else if (!ua_src && (channel == CC1_SCALE1 || channel == CC2_SCALE1))
+ return FLADC_CC_HIGH_RANGE_OFFSET_MV + (fladc * FLADC_CC_HIGH_RANGE_LSB_MV);
+ else if (!ua_src && (channel == CC1_SCALE2 || channel == CC2_SCALE2))
+ return FLADC_CC_LOW_RANGE_OFFSET_MV + (fladc * FLADC_CC_LOW_RANGE_LSB_MV);
+
+ dev_err(chip->dev, "ADC ERROR: SCALE UNKNOWN");
+
+ return -EINVAL;
+}
+
+static int max_contaminant_read_adc_mv(struct max_tcpci_chip *chip, enum fladc_select channel,
+ int sleep_msec, bool raw, bool ua_src)
+{
+ struct regmap *regmap = chip->data.regmap;
+ u8 fladc;
+ int ret;
+
+ /* Channel & scale select */
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_ADC_CTRL1, ADCINSEL_MASK,
+ channel << ADC_CHANNEL_OFFSET);
+ if (ret < 0)
+ return ret;
+
+ /* Enable ADC */
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_ADC_CTRL1, ADCEN, ADCEN);
+ if (ret < 0)
+ return ret;
+
+ usleep_range(sleep_msec * 1000, (sleep_msec + 1) * 1000);
+ ret = max_tcpci_read8(chip, TCPC_VENDOR_FLADC_STATUS, &fladc);
+ if (ret < 0)
+ return ret;
+
+ /* Disable ADC */
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_ADC_CTRL1, ADCEN, 0);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_ADC_CTRL1, ADCINSEL_MASK, 0);
+ if (ret < 0)
+ return ret;
+
+ if (!raw)
+ return max_contaminant_adc_to_mv(chip, channel, ua_src, fladc);
+ else
+ return fladc;
+}
+
+static int max_contaminant_read_resistance_kohm(struct max_tcpci_chip *chip,
+ enum fladc_select channel, int sleep_msec, bool raw)
+{
+ struct regmap *regmap = chip->data.regmap;
+ int mv;
+ int ret;
+
+ if (channel == CC1_SCALE1 || channel == CC2_SCALE1 || channel == CC1_SCALE2 ||
+ channel == CC2_SCALE2) {
+ /* Enable 1uA current source */
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL2, CCLPMODESEL_MASK,
+ ULTRA_LOW_POWER_MODE);
+ if (ret < 0)
+ return ret;
+
+ /* Enable 1uA current source */
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL2, CCRPCTRL_MASK, UA_1_SRC);
+ if (ret < 0)
+ return ret;
+
+ /* OVP disable */
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL2, CCOVPDIS, CCOVPDIS);
+ if (ret < 0)
+ return ret;
+
+ mv = max_contaminant_read_adc_mv(chip, channel, sleep_msec, raw, true);
+ /* OVP enable */
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL2, CCOVPDIS, 0);
+ if (ret < 0)
+ return ret;
+ /* returns KOhm as 1uA source is used. */
+ return mv;
+ }
+
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL2, SBUOVPDIS, SBUOVPDIS);
+ if (ret < 0)
+ return ret;
+
+ /* SBU switches auto configure when channel is selected. */
+ /* Enable 1ua current source */
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL2, SBURPCTRL, SBURPCTRL);
+ if (ret < 0)
+ return ret;
+
+ mv = max_contaminant_read_adc_mv(chip, channel, sleep_msec, raw, true);
+ /* Disable current source */
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL2, SBURPCTRL, 0);
+ if (ret < 0)
+ return ret;
+
+ /* OVP disable */
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL2, SBUOVPDIS, 0);
+ if (ret < 0)
+ return ret;
+
+ return mv;
+}
+
+static void max_contaminant_read_comparators(struct max_tcpci_chip *chip, u8 *vendor_cc_status2_cc1,
+ u8 *vendor_cc_status2_cc2)
+{
+ struct regmap *regmap = chip->data.regmap;
+ int ret;
+
+ /* Enable 80uA source */
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL2, CCRPCTRL_MASK, UA_80_SRC);
+ if (ret < 0)
+ return;
+
+ /* Enable comparators */
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL1, CCCOMPEN, CCCOMPEN);
+ if (ret < 0)
+ return;
+
+ /* Sleep to allow comparators settle */
+ usleep_range(5000, 6000);
+ ret = regmap_update_bits(regmap, TCPC_TCPC_CTRL, TCPC_TCPC_CTRL_ORIENTATION, PLUG_ORNT_CC1);
+ if (ret < 0)
+ return;
+
+ usleep_range(5000, 6000);
+ ret = max_tcpci_read8(chip, VENDOR_CC_STATUS2, vendor_cc_status2_cc1);
+ if (ret < 0)
+ return;
+
+ ret = regmap_update_bits(regmap, TCPC_TCPC_CTRL, TCPC_TCPC_CTRL_ORIENTATION, PLUG_ORNT_CC2);
+ if (ret < 0)
+ return;
+
+ usleep_range(5000, 6000);
+ ret = max_tcpci_read8(chip, VENDOR_CC_STATUS2, vendor_cc_status2_cc2);
+ if (ret < 0)
+ return;
+
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL1, CCCOMPEN, 0);
+ if (ret < 0)
+ return;
+ regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL2, CCRPCTRL_MASK, 0);
+}
+
+static int max_contaminant_detect_contaminant(struct max_tcpci_chip *chip)
+{
+ int cc1_k, cc2_k, sbu1_k, sbu2_k;
+ u8 vendor_cc_status2_cc1 = 0xff, vendor_cc_status2_cc2 = 0xff;
+ u8 role_ctrl = 0, role_ctrl_backup = 0;
+ int inferred_state = NOT_DETECTED;
+
+ max_tcpci_read8(chip, TCPC_ROLE_CTRL, &role_ctrl);
+ role_ctrl_backup = role_ctrl;
+ role_ctrl = 0x0F;
+ max_tcpci_write8(chip, TCPC_ROLE_CTRL, role_ctrl);
+
+ cc1_k = max_contaminant_read_resistance_kohm(chip, CC1_SCALE2, READ1_SLEEP_MS, false);
+ cc2_k = max_contaminant_read_resistance_kohm(chip, CC2_SCALE2, READ2_SLEEP_MS, false);
+
+ sbu1_k = max_contaminant_read_resistance_kohm(chip, SBU1, READ1_SLEEP_MS, false);
+ sbu2_k = max_contaminant_read_resistance_kohm(chip, SBU2, READ2_SLEEP_MS, false);
+ max_contaminant_read_comparators(chip, &vendor_cc_status2_cc1, &vendor_cc_status2_cc2);
+
+ if ((!(CC1_VUFP_RD0P5 & vendor_cc_status2_cc1) ||
+ !(CC2_VUFP_RD0P5 & vendor_cc_status2_cc2)) &&
+ !(CC1_VUFP_RD0P5 & vendor_cc_status2_cc1 && CC2_VUFP_RD0P5 & vendor_cc_status2_cc2))
+ inferred_state = SINK;
+ else if ((cc1_k < CONTAMINANT_THRESHOLD_CC_K || cc2_k < CONTAMINANT_THRESHOLD_CC_K) &&
+ (sbu1_k < CONTAMINANT_THRESHOLD_SBU_K || sbu2_k < CONTAMINANT_THRESHOLD_SBU_K))
+ inferred_state = DETECTED;
+
+ if (inferred_state == NOT_DETECTED)
+ max_tcpci_write8(chip, TCPC_ROLE_CTRL, role_ctrl_backup);
+ else
+ max_tcpci_write8(chip, TCPC_ROLE_CTRL, (TCPC_ROLE_CTRL_DRP | 0xA));
+
+ return inferred_state;
+}
+
+static int max_contaminant_enable_dry_detection(struct max_tcpci_chip *chip)
+{
+ struct regmap *regmap = chip->data.regmap;
+ u8 temp;
+ int ret;
+
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL3, CCWTRDEB_MASK | CCWTRSEL_MASK
+ | WTRCYCLE_MASK, CCWTRDEB_1MS << CCWTRDEB_SHIFT |
+ CCWTRSEL_1V << CCWTRSEL_SHIFT | WTRCYCLE_4_8_S <<
+ WTRCYCLE_SHIFT);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(regmap, TCPC_ROLE_CTRL, TCPC_ROLE_CTRL_DRP, TCPC_ROLE_CTRL_DRP);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL1, CCCONNDRY, CCCONNDRY);
+ if (ret < 0)
+ return ret;
+ ret = max_tcpci_read8(chip, TCPC_VENDOR_CC_CTRL1, &temp);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(regmap, TCPC_VENDOR_CC_CTRL2, CCLPMODESEL_MASK,
+ ULTRA_LOW_POWER_MODE);
+ if (ret < 0)
+ return ret;
+ ret = max_tcpci_read8(chip, TCPC_VENDOR_CC_CTRL2, &temp);
+ if (ret < 0)
+ return ret;
+
+ /* Enable Look4Connection before sending the command */
+ ret = regmap_update_bits(regmap, TCPC_TCPC_CTRL, TCPC_TCPC_CTRL_EN_LK4CONN_ALRT,
+ TCPC_TCPC_CTRL_EN_LK4CONN_ALRT);
+ if (ret < 0)
+ return ret;
+
+ ret = max_tcpci_write8(chip, TCPC_COMMAND, TCPC_CMD_LOOK4CONNECTION);
+ if (ret < 0)
+ return ret;
+ return 0;
+}
+
+bool max_contaminant_is_contaminant(struct max_tcpci_chip *chip, bool disconnect_while_debounce)
+{
+ u8 cc_status, pwr_cntl;
+
+ max_tcpci_read8(chip, TCPC_CC_STATUS, &cc_status);
+ max_tcpci_read8(chip, TCPC_POWER_CTRL, &pwr_cntl);
+
+ if (chip->contaminant_state == NOT_DETECTED || chip->contaminant_state == SINK) {
+ if (!disconnect_while_debounce)
+ msleep(100);
+
+ max_tcpci_read8(chip, TCPC_CC_STATUS, &cc_status);
+ if (IS_CC_OPEN(cc_status)) {
+ u8 role_ctrl, role_ctrl_backup;
+
+ max_tcpci_read8(chip, TCPC_ROLE_CTRL, &role_ctrl);
+ role_ctrl_backup = role_ctrl;
+ role_ctrl |= 0x0F;
+ role_ctrl &= ~(TCPC_ROLE_CTRL_DRP);
+ max_tcpci_write8(chip, TCPC_ROLE_CTRL, role_ctrl);
+
+ chip->contaminant_state = max_contaminant_detect_contaminant(chip);
+
+ max_tcpci_write8(chip, TCPC_ROLE_CTRL, role_ctrl_backup);
+ if (chip->contaminant_state == DETECTED) {
+ max_contaminant_enable_dry_detection(chip);
+ return true;
+ }
+ }
+ return false;
+ } else if (chip->contaminant_state == DETECTED) {
+ if (STATUS_CHECK(cc_status, TCPC_CC_STATUS_TOGGLING, 0)) {
+ chip->contaminant_state = max_contaminant_detect_contaminant(chip);
+ if (chip->contaminant_state == DETECTED) {
+ max_contaminant_enable_dry_detection(chip);
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
+
+MODULE_DESCRIPTION("MAXIM TCPC CONTAMINANT Module");
+MODULE_AUTHOR("Badhri Jagan Sridharan <badhri@google.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/usb/typec/tcpm/tcpci_maxim.h b/drivers/usb/typec/tcpm/tcpci_maxim.h
new file mode 100644
index 000000000000..2c1c4d161b0d
--- /dev/null
+++ b/drivers/usb/typec/tcpm/tcpci_maxim.h
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2022 Google, Inc
+ *
+ * MAXIM TCPC header file.
+ */
+#ifndef TCPCI_MAXIM_H_
+#define TCPCI_MAXIM_H_
+
+#define VENDOR_CC_STATUS2 0x85
+#define CC1_VUFP_RD0P5 BIT(1)
+#define CC2_VUFP_RD0P5 BIT(5)
+#define TCPC_VENDOR_FLADC_STATUS 0x89
+
+#define TCPC_VENDOR_CC_CTRL1 0x8c
+#define CCCONNDRY BIT(7)
+#define CCCOMPEN BIT(5)
+
+#define TCPC_VENDOR_CC_CTRL2 0x8d
+#define SBUOVPDIS BIT(7)
+#define CCOVPDIS BIT(6)
+#define SBURPCTRL BIT(5)
+#define CCLPMODESEL_MASK GENMASK(4, 3)
+#define ULTRA_LOW_POWER_MODE BIT(3)
+#define CCRPCTRL_MASK GENMASK(2, 0)
+#define UA_1_SRC 1
+#define UA_80_SRC 3
+
+#define TCPC_VENDOR_CC_CTRL3 0x8e
+#define CCWTRDEB_MASK GENMASK(7, 6)
+#define CCWTRDEB_SHIFT 6
+#define CCWTRDEB_1MS 1
+#define CCWTRSEL_MASK GENMASK(5, 3)
+#define CCWTRSEL_SHIFT 3
+#define CCWTRSEL_1V 0x4
+#define CCLADDERDIS BIT(2)
+#define WTRCYCLE_MASK BIT(0)
+#define WTRCYCLE_SHIFT 0
+#define WTRCYCLE_2_4_S 0
+#define WTRCYCLE_4_8_S 1
+
+#define TCPC_VENDOR_ADC_CTRL1 0x91
+#define ADCINSEL_MASK GENMASK(7, 5)
+#define ADC_CHANNEL_OFFSET 5
+#define ADCEN BIT(0)
+
+enum contamiant_state {
+ NOT_DETECTED,
+ DETECTED,
+ SINK,
+};
+
+/*
+ * @potential_contaminant:
+ * Last returned result to tcpm indicating whether the TCPM port
+ * has potential contaminant.
+ */
+struct max_tcpci_chip {
+ struct tcpci_data data;
+ struct tcpci *tcpci;
+ struct device *dev;
+ struct i2c_client *client;
+ struct tcpm_port *port;
+ enum contamiant_state contaminant_state;
+};
+
+static inline int max_tcpci_read16(struct max_tcpci_chip *chip, unsigned int reg, u16 *val)
+{
+ return regmap_raw_read(chip->data.regmap, reg, val, sizeof(u16));
+}
+
+static inline int max_tcpci_write16(struct max_tcpci_chip *chip, unsigned int reg, u16 val)
+{
+ return regmap_raw_write(chip->data.regmap, reg, &val, sizeof(u16));
+}
+
+static inline int max_tcpci_read8(struct max_tcpci_chip *chip, unsigned int reg, u8 *val)
+{
+ return regmap_raw_read(chip->data.regmap, reg, val, sizeof(u8));
+}
+
+static inline int max_tcpci_write8(struct max_tcpci_chip *chip, unsigned int reg, u8 val)
+{
+ return regmap_raw_write(chip->data.regmap, reg, &val, sizeof(u8));
+}
+
+bool max_contaminant_is_contaminant(struct max_tcpci_chip *chip, bool disconnect_while_debounce);
+
+#endif // TCPCI_MAXIM_H_
diff --git a/drivers/usb/typec/tcpm/tcpci_maxim.c b/drivers/usb/typec/tcpm/tcpci_maxim_core.c
similarity index 93%
rename from drivers/usb/typec/tcpm/tcpci_maxim.c
rename to drivers/usb/typec/tcpm/tcpci_maxim_core.c
index 83e140ffcc3e..f32cda2a5e3a 100644
--- a/drivers/usb/typec/tcpm/tcpci_maxim.c
+++ b/drivers/usb/typec/tcpm/tcpci_maxim_core.c
@@ -1,6 +1,6 @@
-// SPDX-License-Identifier: GPL-2.0
+// SPDX-License-Identifier: GPL-2.0+
/*
- * Copyright (C) 2020, Google LLC
+ * Copyright (C) 2020 - 2022, Google LLC
*
* MAXIM TCPCI based TCPC driver
*/
@@ -15,6 +15,8 @@
#include <linux/usb/tcpm.h>
#include <linux/usb/typec.h>
+#include "tcpci_maxim.h"
+
#define PD_ACTIVITY_TIMEOUT_MS 10000
#define TCPC_VENDOR_ALERT 0x80
@@ -39,14 +41,6 @@
#define MAX_BUCK_BOOST_SOURCE 0xa
#define MAX_BUCK_BOOST_SINK 0x5
-struct max_tcpci_chip {
- struct tcpci_data data;
- struct tcpci *tcpci;
- struct device *dev;
- struct i2c_client *client;
- struct tcpm_port *port;
-};
-
static const struct regmap_range max_tcpci_tcpci_range[] = {
regmap_reg_range(0x00, 0x95)
};
@@ -68,26 +62,6 @@ static struct max_tcpci_chip *tdata_to_max_tcpci(struct tcpci_data *tdata)
return container_of(tdata, struct max_tcpci_chip, data);
}
-static int max_tcpci_read16(struct max_tcpci_chip *chip, unsigned int reg, u16 *val)
-{
- return regmap_raw_read(chip->data.regmap, reg, val, sizeof(u16));
-}
-
-static int max_tcpci_write16(struct max_tcpci_chip *chip, unsigned int reg, u16 val)
-{
- return regmap_raw_write(chip->data.regmap, reg, &val, sizeof(u16));
-}
-
-static int max_tcpci_read8(struct max_tcpci_chip *chip, unsigned int reg, u8 *val)
-{
- return regmap_raw_read(chip->data.regmap, reg, val, sizeof(u8));
-}
-
-static int max_tcpci_write8(struct max_tcpci_chip *chip, unsigned int reg, u8 val)
-{
- return regmap_raw_write(chip->data.regmap, reg, &val, sizeof(u8));
-}
-
static void max_tcpci_init_regs(struct max_tcpci_chip *chip)
{
u16 alert_mask = 0;
@@ -348,8 +322,14 @@ static irqreturn_t _max_tcpci_irq(struct max_tcpci_chip *chip, u16 status)
if (status & TCPC_ALERT_VBUS_DISCNCT)
tcpm_vbus_change(chip->port);
- if (status & TCPC_ALERT_CC_STATUS)
- tcpm_cc_change(chip->port);
+ if (status & TCPC_ALERT_CC_STATUS) {
+ if (chip->contaminant_state == DETECTED || tcpm_port_is_toggling(chip->port)) {
+ if (!max_contaminant_is_contaminant(chip, false))
+ tcpm_port_clean(chip->port);
+ } else {
+ tcpm_cc_change(chip->port);
+ }
+ }
if (status & TCPC_ALERT_POWER_STATUS)
process_power_status(chip);
@@ -438,6 +418,14 @@ static int tcpci_init(struct tcpci *tcpci, struct tcpci_data *data)
return -1;
}
+static void max_tcpci_check_contaminant(struct tcpci *tcpci, struct tcpci_data *tdata)
+{
+ struct max_tcpci_chip *chip = tdata_to_max_tcpci(tdata);
+
+ if (!max_contaminant_is_contaminant(chip, true))
+ tcpm_port_clean(chip->port);
+}
+
static int max_tcpci_probe(struct i2c_client *client)
{
int ret;
@@ -471,6 +459,7 @@ static int max_tcpci_probe(struct i2c_client *client)
chip->data.auto_discharge_disconnect = true;
chip->data.vbus_vsafe0v = true;
chip->data.set_partner_usb_comm_capable = max_tcpci_set_partner_usb_comm_capable;
+ chip->data.check_contaminant = max_tcpci_check_contaminant;
max_tcpci_init_regs(chip);
chip->tcpci = tcpci_register_port(chip->dev, &chip->data);
--
2.39.0.rc1.256.g54fd8350bd-goog
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH v10 1/3] usb: typec: tcpm: Add callbacks to mitigate wakeups due to contaminant
2022-12-10 18:51 [PATCH v10 1/3] usb: typec: tcpm: Add callbacks to mitigate wakeups due to contaminant Badhri Jagan Sridharan
2022-12-10 18:51 ` [PATCH v10 2/3] usb: typec: tcpci: Add callback for evaluating contaminant presence Badhri Jagan Sridharan
2022-12-10 18:51 ` [PATCH v10 3/3] usb: typec: maxim_contaminant: Implement check_contaminant callback Badhri Jagan Sridharan
@ 2022-12-10 19:09 ` Guenter Roeck
2022-12-23 10:42 ` Badhri Jagan Sridharan
2 siblings, 1 reply; 5+ messages in thread
From: Guenter Roeck @ 2022-12-10 19:09 UTC (permalink / raw)
To: Badhri Jagan Sridharan, Heikki Krogerus, Greg Kroah-Hartman
Cc: linux-usb, linux-kernel, Kyle Tso
On 12/10/22 10:51, Badhri Jagan Sridharan wrote:
> On some of the TCPC implementations, when the Type-C port is exposed
> to contaminants, such as water, TCPC stops toggling while reporting OPEN
> either by the time TCPM reads CC pin status or during CC debounce
> window. This causes TCPM to be stuck in TOGGLING state. If TCPM is made
> to restart toggling, the behavior recurs causing redundant CPU wakeups
> till the USB-C port is free of contaminant.
>
> [206199.287817] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
> [206199.640337] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
> [206199.985789] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
>
> (or)
>
> [ 7853.867577] Start toggling
> [ 7853.889921] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
> [ 7855.698765] CC1: 0 -> 0, CC2: 0 -> 5 [state TOGGLING, polarity 0, connected]
> [ 7855.698790] state change TOGGLING -> SNK_ATTACH_WAIT [rev3 NONE_AMS]
> [ 7855.698826] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev3 NONE_AMS]
> [ 7855.703559] CC1: 0 -> 0, CC2: 5 -> 5 [state SNK_ATTACH_WAIT, polarity 0, connected]
> [ 7855.856555] CC1: 0 -> 0, CC2: 5 -> 0 [state SNK_ATTACH_WAIT, polarity 0, disconnected]
> [ 7855.856581] state change SNK_ATTACH_WAIT -> SNK_ATTACH_WAIT [rev3 NONE_AMS]
> [ 7855.856613] pending state change SNK_ATTACH_WAIT -> SNK_UNATTACHED @ 170 ms [rev3 NONE_AMS]
> [ 7856.027744] state change SNK_ATTACH_WAIT -> SNK_UNATTACHED [delayed 170 ms]
> [ 7856.181949] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
> [ 7856.187896] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
> [ 7857.645630] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
> [ 7857.647291] CC1: 0 -> 0, CC2: 0 -> 5 [state TOGGLING, polarity 0, connected]
> [ 7857.647298] state change TOGGLING -> SNK_ATTACH_WAIT [rev3 NONE_AMS]
> [ 7857.647310] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev3 NONE_AMS]
> [ 7857.808106] CC1: 0 -> 0, CC2: 5 -> 0 [state SNK_ATTACH_WAIT, polarity 0, disconnected]
> [ 7857.808123] state change SNK_ATTACH_WAIT -> SNK_ATTACH_WAIT [rev3 NONE_AMS]
> [ 7857.808150] pending state change SNK_ATTACH_WAIT -> SNK_UNATTACHED @ 170 ms [rev3 NONE_AMS]
> [ 7857.978727] state change SNK_ATTACH_WAIT -> SNK_UNATTACHED [delayed 170 ms]
>
> To mitigate redundant TCPM wakeups, TCPCs which do have the needed hardware
> can implement the check_contaminant callback which is invoked by TCPM
> to evaluate for presence of contaminant. Lower level TCPC driver can
> restart toggling through TCPM_PORT_CLEAN event when the driver detects
> that USB-C port is free of contaminant.
>
> Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
> ---
> Changes since v9:
> * Invoke tcpm_start_toggling before transitioning to TOGGLING from
> * CHECK_CONTAMINANT.
> Changes since v7:
> * None. Skipped versions by mistake.
> Changes since v6:
> * folded the debounce logic into tcpm state machine and removed tcpm
> * state export.
> * Added a helper to determine whether the port is in toggling state.
> * Excluded CHECK_CONTAMINANT from tcpm_log.
> Changes since v5:
> * Updated commit message. Removed change id.
> Changes since v4:
> * None
> Changes since v3:
> * None
> Changes since V2:
> * Offloaded tcpm from maintaining disconnect_while_debouncing logic
> * to lower level maxim tcpc driver based on feedback.
> ---
> drivers/usb/typec/tcpm/tcpm.c | 52 ++++++++++++++++++++++++++++++++++-
> include/linux/usb/tcpm.h | 8 ++++++
> 2 files changed, 59 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 904c7b4ce2f0..0019cacee97c 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -36,6 +36,7 @@
> #define FOREACH_STATE(S) \
> S(INVALID_STATE), \
> S(TOGGLING), \
> + S(CHECK_CONTAMINANT), \
> S(SRC_UNATTACHED), \
> S(SRC_ATTACH_WAIT), \
> S(SRC_ATTACHED), \
> @@ -249,6 +250,7 @@ enum frs_typec_current {
> #define TCPM_RESET_EVENT BIT(2)
> #define TCPM_FRS_EVENT BIT(3)
> #define TCPM_SOURCING_VBUS BIT(4)
> +#define TCPM_PORT_CLEAN BIT(5)
>
> #define LOG_BUFFER_ENTRIES 1024
> #define LOG_BUFFER_ENTRY_SIZE 128
> @@ -483,6 +485,13 @@ struct tcpm_port {
> * SNK_READY for non-pd link.
> */
> bool slow_charger_loop;
> +
> + /*
> + * When true indicates that the lower level drivers indicate potential presence
> + * of contaminant in the connector pins based on the tcpm state machine
> + * transitions.
> + */
> + bool potential_contaminant;
> #ifdef CONFIG_DEBUG_FS
> struct dentry *dentry;
> struct mutex logbuffer_lock; /* log buffer access lock */
> @@ -647,7 +656,7 @@ static void tcpm_log(struct tcpm_port *port, const char *fmt, ...)
> /* Do not log while disconnected and unattached */
> if (tcpm_port_is_disconnected(port) &&
> (port->state == SRC_UNATTACHED || port->state == SNK_UNATTACHED ||
> - port->state == TOGGLING))
> + port->state == TOGGLING || port->state == CHECK_CONTAMINANT))
> return;
>
> va_start(args, fmt);
> @@ -3904,15 +3913,28 @@ static void run_state_machine(struct tcpm_port *port)
> unsigned int msecs;
> enum tcpm_state upcoming_state;
>
> + if (port->tcpc->check_contaminant && port->state != CHECK_CONTAMINANT)
> + port->potential_contaminant = ((port->enter_state == SRC_ATTACH_WAIT &&
> + port->state == SRC_UNATTACHED) ||
> + (port->enter_state == SNK_ATTACH_WAIT &&
> + port->state == SNK_UNATTACHED));
> +
> port->enter_state = port->state;
> switch (port->state) {
> case TOGGLING:
> break;
> + case CHECK_CONTAMINANT:
> + port->tcpc->check_contaminant(port->tcpc);
> + break;
> /* SRC states */
> case SRC_UNATTACHED:
> if (!port->non_pd_role_swap)
> tcpm_swap_complete(port, -ENOTCONN);
> tcpm_src_detach(port);
> + if (port->potential_contaminant) {
> + tcpm_set_state(port, CHECK_CONTAMINANT, 0);
> + break;
> + }
> if (tcpm_start_toggling(port, tcpm_rp_cc(port))) {
> tcpm_set_state(port, TOGGLING, 0);
> break;
> @@ -4150,6 +4172,10 @@ static void run_state_machine(struct tcpm_port *port)
> tcpm_swap_complete(port, -ENOTCONN);
> tcpm_pps_complete(port, -ENOTCONN);
> tcpm_snk_detach(port);
> + if (port->potential_contaminant) {
> + tcpm_set_state(port, CHECK_CONTAMINANT, 0);
> + break;
> + }
> if (tcpm_start_toggling(port, TYPEC_CC_RD)) {
> tcpm_set_state(port, TOGGLING, 0);
> break;
> @@ -4926,6 +4952,9 @@ static void _tcpm_cc_change(struct tcpm_port *port, enum typec_cc_status cc1,
> else if (tcpm_port_is_sink(port))
> tcpm_set_state(port, SNK_ATTACH_WAIT, 0);
> break;
> + case CHECK_CONTAMINANT:
> + /* Wait for Toggling to be resumed */
> + break;
> case SRC_UNATTACHED:
> case ACC_UNATTACHED:
> if (tcpm_port_is_debug(port) || tcpm_port_is_audio(port) ||
> @@ -5425,6 +5454,12 @@ static void tcpm_pd_event_handler(struct kthread_work *work)
> port->vbus_source = true;
> _tcpm_pd_vbus_on(port);
> }
> + if (events & TCPM_PORT_CLEAN) {
> + tcpm_log(port, "port clean");
> + if (port->state == CHECK_CONTAMINANT &&
> + tcpm_start_toggling(port, tcpm_rp_cc(port)))
> + tcpm_set_state(port, TOGGLING, 0);
> + }
This needs an else case, or the state machine will be stuck in
CHECK_CONTAMINANT state if tcpm_start_toggling() returns false.
Also, I am a bit concerned that the cc value gets lost if the
CHECK_CONTAMINANT state was entered through SRC_UNATTACHED.
I don't really know off hand how to resolve that since the
next state also depends on the pre-CHECK_CONTAMINANT state
if tcpm_start_toggling() fails.
Guenter
>
> spin_lock(&port->pd_event_lock);
> }
> @@ -5477,6 +5512,21 @@ void tcpm_sourcing_vbus(struct tcpm_port *port)
> }
> EXPORT_SYMBOL_GPL(tcpm_sourcing_vbus);
>
> +void tcpm_port_clean(struct tcpm_port *port)
> +{
> + spin_lock(&port->pd_event_lock);
> + port->pd_events |= TCPM_PORT_CLEAN;
> + spin_unlock(&port->pd_event_lock);
> + kthread_queue_work(port->wq, &port->event_work);
> +}
> +EXPORT_SYMBOL_GPL(tcpm_port_clean);
> +
> +bool tcpm_port_is_toggling(struct tcpm_port *port)
> +{
> + return port->port_type == TYPEC_PORT_DRP && port->state == TOGGLING;
> +}
> +EXPORT_SYMBOL_GPL(tcpm_port_is_toggling);
> +
> static void tcpm_enable_frs_work(struct kthread_work *work)
> {
> struct tcpm_port *port = container_of(work, struct tcpm_port, enable_frs);
> diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h
> index bffc8d3e14ad..ab7ca872950b 100644
> --- a/include/linux/usb/tcpm.h
> +++ b/include/linux/usb/tcpm.h
> @@ -114,6 +114,11 @@ enum tcpm_transmit_type {
> * Optional; The USB Communications Capable bit indicates if port
> * partner is capable of communication over the USB data lines
> * (e.g. D+/- or SS Tx/Rx). Called to notify the status of the bit.
> + * @check_contaminant:
> + * Optional; The callback is called when CC pins report open status
> + * at the end of the deboumce period or when the port is still
> + * toggling. Chip level drivers are expected to check for contaminant
> + * and call tcpm_clean_port when the port is clean.
> */
> struct tcpc_dev {
> struct fwnode_handle *fwnode;
> @@ -148,6 +153,7 @@ struct tcpc_dev {
> bool pps_active, u32 requested_vbus_voltage);
> bool (*is_vbus_vsafe0v)(struct tcpc_dev *dev);
> void (*set_partner_usb_comm_capable)(struct tcpc_dev *dev, bool enable);
> + void (*check_contaminant)(struct tcpc_dev *dev);
> };
>
> struct tcpm_port;
> @@ -165,5 +171,7 @@ void tcpm_pd_transmit_complete(struct tcpm_port *port,
> enum tcpm_transmit_status status);
> void tcpm_pd_hard_reset(struct tcpm_port *port);
> void tcpm_tcpc_reset(struct tcpm_port *port);
> +void tcpm_port_clean(struct tcpm_port *port);
> +bool tcpm_port_is_toggling(struct tcpm_port *port);
>
> #endif /* __LINUX_USB_TCPM_H */
>
> base-commit: 1524ceb14dd5ebd6f724d993c5ec1a9a8d445d8e
^ permalink raw reply [flat|nested] 5+ messages in thread