* [PATCH v3 3/5] regulator: sy7636a: bind to the I2C device directly
2026-11-08 9:35 [PATCH v3 0/5] sy7636a: power the panel only during updates Pablo Mazzini
2026-11-08 9:35 ` [PATCH v3 1/5] regulator: sy7636a: don't wait for power good if already on Pablo Mazzini
2026-11-08 9:35 ` [PATCH v3 2/5] hwmon: sy7636a: fix negative temperatures Pablo Mazzini
@ 2026-11-08 9:36 ` Pablo Mazzini
2026-11-08 9:36 ` [PATCH v3 4/5] hwmon: sy7636a: read the temperature only while the rails are on Pablo Mazzini
2026-11-08 9:36 ` [PATCH v3 5/5] ARM: imx_v6_v7_defconfig: drop the SY7636A MFD option Pablo Mazzini
4 siblings, 0 replies; 6+ messages in thread
From: Pablo Mazzini @ 2026-11-08 9:36 UTC (permalink / raw)
To: Mark Brown, Liam Girdwood, Guenter Roeck, Lee Jones
Cc: Pablo Mazzini, Alistair Francis, Andreas Kemnade, linux-hwmon,
mfd, linux-kernel
Bind the regulator to the chip directly, as the TPS65185 and FP9931
drivers do, and have it create an auxiliary device for the hwmon driver,
instead of simple-mfd-i2c creating a cell for each. Drop the MFD glue
and header. It now probes before the GPIOs may be ready, so report the
power good GPIO with dev_err_probe(). The hwmon driver then only
accesses the chip after vin-supply is enabled.
Signed-off-by: Pablo Mazzini <pmazzini@gmail.com>
---
drivers/hwmon/Kconfig | 2 +-
drivers/hwmon/sy7636a-hwmon.c | 33 +++++-----
drivers/mfd/Kconfig | 10 ----
drivers/mfd/simple-mfd-i2c.c | 11 ----
drivers/regulator/Kconfig | 4 +-
drivers/regulator/sy7636a-regulator.c | 86 ++++++++++++++++-----------
include/linux/mfd/sy7636a.h | 34 -----------
7 files changed, 72 insertions(+), 108 deletions(-)
delete mode 100644 include/linux/mfd/sy7636a.h
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 18c682e1a475..247507a4ddde 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -2106,7 +2106,7 @@ config SENSORS_SIS5595
config SENSORS_SY7636A
tristate "Silergy SY7636A"
- depends on MFD_SY7636A
+ depends on REGULATOR_SY7636A
help
If you say yes here you get support for the thermistor readout of
the Silergy SY7636A PMIC.
diff --git a/drivers/hwmon/sy7636a-hwmon.c b/drivers/hwmon/sy7636a-hwmon.c
index f01f368d68e5..a6b47452e29e 100644
--- a/drivers/hwmon/sy7636a-hwmon.c
+++ b/drivers/hwmon/sy7636a-hwmon.c
@@ -8,15 +8,14 @@
* Alistair Francis <alistair@alistair23.me>
*/
+#include <linux/auxiliary_bus.h>
#include <linux/err.h>
#include <linux/hwmon.h>
-#include <linux/init.h>
#include <linux/module.h>
-#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/machine.h>
-#include <linux/mfd/sy7636a.h>
+#define SY7636A_REG_TERMISTOR_READOUT 0x08
static int sy7636a_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *temp)
@@ -63,40 +62,44 @@ static const struct hwmon_chip_info sy7636a_chip_info = {
.info = sy7636a_info,
};
-static int sy7636a_sensor_probe(struct platform_device *pdev)
+static int sy7636a_sensor_probe(struct auxiliary_device *adev,
+ const struct auxiliary_device_id *id)
{
- struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ struct regmap *regmap = dev_get_regmap(adev->dev.parent, NULL);
struct device *hwmon_dev;
int err;
if (!regmap)
- return -EPROBE_DEFER;
+ return -ENODEV;
- err = devm_regulator_get_enable(&pdev->dev, "vcom");
+ err = devm_regulator_get_enable(&adev->dev, "vcom");
if (err)
return err;
- hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
+ hwmon_dev = devm_hwmon_device_register_with_info(&adev->dev,
"sy7636a_temperature", regmap,
&sy7636a_chip_info, NULL);
if (IS_ERR(hwmon_dev)) {
err = PTR_ERR(hwmon_dev);
- dev_err(&pdev->dev, "Unable to register hwmon device, returned %d\n", err);
+ dev_err(&adev->dev, "Unable to register hwmon device, returned %d\n", err);
return err;
}
return 0;
}
-static struct platform_driver sy7636a_sensor_driver = {
+static const struct auxiliary_device_id sy7636a_sensor_ids[] = {
+ { .name = "sy7636a_regulator.hwmon" },
+ { }
+};
+MODULE_DEVICE_TABLE(auxiliary, sy7636a_sensor_ids);
+
+static struct auxiliary_driver sy7636a_sensor_driver = {
.probe = sy7636a_sensor_probe,
- .driver = {
- .name = "sy7636a-temperature",
- },
+ .id_table = sy7636a_sensor_ids,
};
-module_platform_driver(sy7636a_sensor_driver);
+module_auxiliary_driver(sy7636a_sensor_driver);
MODULE_DESCRIPTION("SY7636A sensor driver");
MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:sy7636a-temperature");
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 87ed55c155f0..c7ff8997beb1 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1319,16 +1319,6 @@ config MFD_SPMI_PMIC
Say M here if you want to include support for the SPMI PMIC
series as a module. The module will be called "qcom-spmi-pmic".
-config MFD_SY7636A
- tristate "Silergy SY7636A voltage regulator"
- depends on I2C
- select MFD_SIMPLE_MFD_I2C
- help
- Enable support for Silergy SY7636A voltage regulator.
-
- To enable support for building sub-devices as modules,
- choose M here.
-
config MFD_RDC321X
tristate "RDC R-321x southbridge"
select MFD_CORE
diff --git a/drivers/mfd/simple-mfd-i2c.c b/drivers/mfd/simple-mfd-i2c.c
index ef3ce4bdf98b..0c9162034899 100644
--- a/drivers/mfd/simple-mfd-i2c.c
+++ b/drivers/mfd/simple-mfd-i2c.c
@@ -67,16 +67,6 @@ static int simple_mfd_i2c_probe(struct i2c_client *i2c)
return ret;
}
-static const struct mfd_cell sy7636a_cells[] = {
- { .name = "sy7636a-regulator", },
- { .name = "sy7636a-temperature", },
-};
-
-static const struct simple_mfd_data silergy_sy7636a = {
- .mfd_cell = sy7636a_cells,
- .mfd_cell_size = ARRAY_SIZE(sy7636a_cells),
-};
-
static const struct mfd_cell max5970_cells[] = {
{ .name = "max5970-regulator", },
{ .name = "max5970-iio", },
@@ -124,7 +114,6 @@ static const struct of_device_id simple_mfd_i2c_of_match[] = {
{ .compatible = "maxim,max5970", .data = &maxim_max5970 },
{ .compatible = "maxim,max5978", .data = &maxim_max5970 },
{ .compatible = "maxim,max77705-battery", .data = &maxim_mon_max77705 },
- { .compatible = "silergy,sy7636a", .data = &silergy_sy7636a },
{ .compatible = "spacemit,p1", .data = &spacemit_p1 },
{}
};
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 4a57feae3560..2ed21d57df75 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -1621,7 +1621,9 @@ config REGULATOR_SUN20I
config REGULATOR_SY7636A
tristate "Silergy SY7636A voltage regulator"
- depends on MFD_SY7636A
+ depends on I2C
+ select AUXILIARY_BUS
+ select REGMAP_I2C
help
This driver supports Silergy SY7636A voltage regulator.
diff --git a/drivers/regulator/sy7636a-regulator.c b/drivers/regulator/sy7636a-regulator.c
index 6269c50348ac..7540ed79a649 100644
--- a/drivers/regulator/sy7636a-regulator.c
+++ b/drivers/regulator/sy7636a-regulator.c
@@ -7,18 +7,26 @@
// Authors: Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>
// Alistair Francis <alistair@alistair23.me>
+#include <linux/auxiliary_bus.h>
#include <linux/completion.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
-#include <linux/mfd/sy7636a.h>
#include <linux/module.h>
-#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regmap.h>
+#define SY7636A_REG_OPERATION_MODE_CRL 0x00
+#define SY7636A_OPERATION_MODE_CRL_ONOFF BIT(7)
+#define SY7636A_REG_VCOM_ADJUST_CTRL_L 0x01
+#define SY7636A_REG_VCOM_ADJUST_CTRL_H 0x02
+#define SY7636A_REG_POWER_ON_DELAY_TIME 0x06
+
+#define VCOM_ADJUST_CTRL_MASK 0x1ff
+#define VCOM_ADJUST_CTRL_SCAL 10000
+
#define PGOOD_TIMEOUT_MSECS 200
struct sy7636a_data {
@@ -137,50 +145,54 @@ static const struct regulator_desc desc = {
.of_match = of_match_ptr("vcom"),
};
-static int sy7636a_regulator_probe(struct platform_device *pdev)
+static const struct regmap_config sy7636a_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+static int sy7636a_regulator_probe(struct i2c_client *client)
{
- struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ struct device *dev = &client->dev;
struct regulator_config config = { };
+ struct auxiliary_device *adev;
struct regulator_dev *rdev;
struct gpio_desc *gdp;
struct sy7636a_data *data;
+ struct regmap *regmap;
int irq, ret;
- if (!regmap)
- return -EPROBE_DEFER;
-
- device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent);
+ regmap = devm_regmap_init_i2c(client, &sy7636a_regmap_config);
+ if (IS_ERR(regmap))
+ return dev_err_probe(dev, PTR_ERR(regmap), "failed to allocate regmap\n");
- gdp = devm_gpiod_get(&pdev->dev, "epd-pwr-good", GPIOD_IN);
- if (IS_ERR(gdp)) {
- dev_err(&pdev->dev, "Power good GPIO fault %ld\n", PTR_ERR(gdp));
- return PTR_ERR(gdp);
- }
+ gdp = devm_gpiod_get(dev, "epd-pwr-good", GPIOD_IN);
+ if (IS_ERR(gdp))
+ return dev_err_probe(dev, PTR_ERR(gdp), "Power good GPIO fault\n");
- data = devm_kzalloc(&pdev->dev, sizeof(struct sy7636a_data), GFP_KERNEL);
+ data = devm_kzalloc(dev, sizeof(struct sy7636a_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->regmap = regmap;
data->pgood_gpio = gdp;
- ret = devm_regulator_get_enable_optional(&pdev->dev, "vin");
+ ret = devm_regulator_get_enable_optional(dev, "vin");
if (ret)
- return dev_err_probe(&pdev->dev, ret,
+ return dev_err_probe(dev, ret,
"failed to get vin regulator\n");
- data->en_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
+ data->en_gpio = devm_gpiod_get_optional(dev, "enable",
GPIOD_OUT_HIGH);
if (IS_ERR(data->en_gpio))
- return dev_err_probe(&pdev->dev,
+ return dev_err_probe(dev,
PTR_ERR(data->en_gpio),
"failed to get en gpio\n");
/* Let VCOM just follow the default power on sequence */
- data->vcom_en_gpio = devm_gpiod_get_optional(&pdev->dev,
+ data->vcom_en_gpio = devm_gpiod_get_optional(dev,
"vcom-en", GPIOD_OUT_LOW);
if (IS_ERR(data->vcom_en_gpio))
- return dev_err_probe(&pdev->dev,
+ return dev_err_probe(dev,
PTR_ERR(data->vcom_en_gpio),
"failed to get vcom-en gpio\n");
@@ -188,54 +200,56 @@ static int sy7636a_regulator_probe(struct platform_device *pdev)
if (data->en_gpio)
usleep_range(2500, 4000);
- platform_set_drvdata(pdev, data);
+ i2c_set_clientdata(client, data);
ret = regmap_write(regmap, SY7636A_REG_POWER_ON_DELAY_TIME, 0x0);
if (ret) {
- dev_err(pdev->dev.parent, "Failed to initialize regulator: %d\n", ret);
+ dev_err(dev, "Failed to initialize regulator: %d\n", ret);
return ret;
}
irq = gpiod_to_irq(data->pgood_gpio);
if (irq < 0)
- return dev_err_probe(&pdev->dev, irq, "no power good interrupt\n");
+ return dev_err_probe(dev, irq, "no power good interrupt\n");
init_completion(&data->pgood_completion);
- ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, sy7636a_pgood_handler,
+ ret = devm_request_threaded_irq(dev, irq, NULL, sy7636a_pgood_handler,
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
"sy7636a-pgood", data);
if (ret)
- return dev_err_probe(&pdev->dev, ret,
- "failed to request power good interrupt\n");
+ return dev_err_probe(dev, ret, "failed to request power good interrupt\n");
- config.dev = &pdev->dev;
+ config.dev = dev;
config.regmap = regmap;
- rdev = devm_regulator_register(&pdev->dev, &desc, &config);
+ rdev = devm_regulator_register(dev, &desc, &config);
if (IS_ERR(rdev)) {
- dev_err(pdev->dev.parent, "Failed to register %s regulator\n",
- pdev->name);
+ dev_err(dev, "Failed to register %s regulator\n", desc.name);
return PTR_ERR(rdev);
}
+ adev = devm_auxiliary_device_create(dev, "hwmon", NULL);
+ if (!adev)
+ return dev_err_probe(dev, -ENODEV, "failed to create hwmon device\n");
+
return 0;
}
-static const struct platform_device_id sy7636a_regulator_id_table[] = {
- { .name = "sy7636a-regulator" },
+static const struct of_device_id sy7636a_of_match[] = {
+ { .compatible = "silergy,sy7636a" },
{ }
};
-MODULE_DEVICE_TABLE(platform, sy7636a_regulator_id_table);
+MODULE_DEVICE_TABLE(of, sy7636a_of_match);
-static struct platform_driver sy7636a_regulator_driver = {
+static struct i2c_driver sy7636a_regulator_driver = {
.driver = {
.name = "sy7636a-regulator",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ .of_match_table = sy7636a_of_match,
},
.probe = sy7636a_regulator_probe,
- .id_table = sy7636a_regulator_id_table,
};
-module_platform_driver(sy7636a_regulator_driver);
+module_i2c_driver(sy7636a_regulator_driver);
MODULE_AUTHOR("Lars Ivar Miljeteig <lars.ivar.miljeteig@remarkable.com>");
MODULE_DESCRIPTION("SY7636A voltage regulator driver");
diff --git a/include/linux/mfd/sy7636a.h b/include/linux/mfd/sy7636a.h
deleted file mode 100644
index 22f03b2f851e..000000000000
--- a/include/linux/mfd/sy7636a.h
+++ /dev/null
@@ -1,34 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Functions to access SY3686A power management chip.
- *
- * Copyright (C) 2021 reMarkable AS - http://www.remarkable.com/
- */
-
-#ifndef __MFD_SY7636A_H
-#define __MFD_SY7636A_H
-
-#define SY7636A_REG_OPERATION_MODE_CRL 0x00
-/* It is set if a gpio is used to control the regulator */
-#define SY7636A_OPERATION_MODE_CRL_VCOMCTL BIT(6)
-#define SY7636A_OPERATION_MODE_CRL_ONOFF BIT(7)
-#define SY7636A_REG_VCOM_ADJUST_CTRL_L 0x01
-#define SY7636A_REG_VCOM_ADJUST_CTRL_H 0x02
-#define SY7636A_REG_VCOM_ADJUST_CTRL_MASK 0x01ff
-#define SY7636A_REG_VLDO_VOLTAGE_ADJULST_CTRL 0x03
-#define SY7636A_REG_POWER_ON_DELAY_TIME 0x06
-#define SY7636A_REG_FAULT_FLAG 0x07
-#define SY7636A_FAULT_FLAG_PG BIT(0)
-#define SY7636A_REG_TERMISTOR_READOUT 0x08
-
-#define SY7636A_REG_MAX 0x08
-
-#define VCOM_ADJUST_CTRL_MASK 0x1ff
-// Used to shift the high byte
-#define VCOM_ADJUST_CTRL_SHIFT 8
-// Used to scale from VCOM_ADJUST_CTRL to mv
-#define VCOM_ADJUST_CTRL_SCAL 10000
-
-#define FAULT_FLAG_SHIFT 1
-
-#endif /* __LINUX_MFD_SY7636A_H */
--
2.52.0
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH v3 4/5] hwmon: sy7636a: read the temperature only while the rails are on
2026-11-08 9:35 [PATCH v3 0/5] sy7636a: power the panel only during updates Pablo Mazzini
` (2 preceding siblings ...)
2026-11-08 9:36 ` [PATCH v3 3/5] regulator: sy7636a: bind to the I2C device directly Pablo Mazzini
@ 2026-11-08 9:36 ` Pablo Mazzini
2026-11-08 9:36 ` [PATCH v3 5/5] ARM: imx_v6_v7_defconfig: drop the SY7636A MFD option Pablo Mazzini
4 siblings, 0 replies; 6+ messages in thread
From: Pablo Mazzini @ 2026-11-08 9:36 UTC (permalink / raw)
To: Guenter Roeck
Cc: Pablo Mazzini, Alistair Francis, Andreas Kemnade, linux-hwmon,
linux-kernel
The driver enables VCOM at probe, which keeps the panel's high voltage
rails on for good. Read the temperature only while the rails are on, when
the chip samples it, and return -ENODATA otherwise. Read power good with
it in one transfer, so the value can not be from before the first sample
or after the rails went off. Register it under the chip name, as the
TPS65185 and FP9931 drivers do.
Signed-off-by: Pablo Mazzini <pmazzini@gmail.com>
---
drivers/hwmon/sy7636a-hwmon.c | 37 +++++++++++++++++++++++------------
1 file changed, 25 insertions(+), 12 deletions(-)
diff --git a/drivers/hwmon/sy7636a-hwmon.c b/drivers/hwmon/sy7636a-hwmon.c
index a6b47452e29e..0c0601d47b87 100644
--- a/drivers/hwmon/sy7636a-hwmon.c
+++ b/drivers/hwmon/sy7636a-hwmon.c
@@ -9,26 +9,43 @@
*/
#include <linux/auxiliary_bus.h>
+#include <linux/bits.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/module.h>
#include <linux/regmap.h>
-#include <linux/regulator/machine.h>
-#define SY7636A_REG_TERMISTOR_READOUT 0x08
+#define SY7636A_REG_FAULT_FLAG 0x07
+#define SY7636A_FAULT_FLAG_PG BIT(0)
static int sy7636a_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *temp)
{
struct regmap *regmap = dev_get_drvdata(dev);
- int ret, reg_val;
-
- ret = regmap_read(regmap,
- SY7636A_REG_TERMISTOR_READOUT, ®_val);
+ u8 buf[2];
+ int ret;
+
+ /*
+ * The thermistor is sampled while ON_OFF is set, but the first sample
+ * is only ready after the ADC sampling and conversion time (ADC_SPL +
+ * ADC_DEL in the datasheet); until then it holds its reset value, 0.
+ * PG is only set once all rails are up, after the first sample, so
+ * read it in the same transfer and report the temperature only while
+ * it is set.
+ *
+ * With ON_OFF set but PG low (rails still ramping up, or a fault), no
+ * temperature is reported even if one may be available. That is
+ * accepted: the display driver reads the temperature only while it
+ * holds the rails on, after power good.
+ */
+ ret = regmap_bulk_read(regmap, SY7636A_REG_FAULT_FLAG, buf, sizeof(buf));
if (ret)
return ret;
- *temp = (s8)reg_val * 1000;
+ if (!(buf[0] & SY7636A_FAULT_FLAG_PG))
+ return -ENODATA;
+
+ *temp = (s8)buf[1] * 1000;
return 0;
}
@@ -72,12 +89,8 @@ static int sy7636a_sensor_probe(struct auxiliary_device *adev,
if (!regmap)
return -ENODEV;
- err = devm_regulator_get_enable(&adev->dev, "vcom");
- if (err)
- return err;
-
hwmon_dev = devm_hwmon_device_register_with_info(&adev->dev,
- "sy7636a_temperature", regmap,
+ "sy7636a", regmap,
&sy7636a_chip_info, NULL);
if (IS_ERR(hwmon_dev)) {
--
2.52.0
^ permalink raw reply [flat|nested] 6+ messages in thread