[PATCH v9 0/8] spacemit: introduce P1 PMIC support

[PATCH v9 0/8] spacemit: introduce P1 PMIC support

[Alex Elder]

The SpacemiT P1 is an I2C-controlled PMIC that implements 6 buck
converters and 12 LDOs.  It contains a load switch, ADC channels,
GPIOs, a real-time clock, and a watchdog timer.

This series introduces a multifunction driver for the P1 PMIC as well
as drivers for its regulators and RTC.

Version 8 provided the ability in "simple-mfd-i2c.c" to specify the
max_register value for the regmap configuration as an alternative
to providing a "full" regmap structure.  Lee Jones asked that the
max_register value take precedence if the regmap_config was also
provided.

This version changes a few things from v8:
  - Alexandre Belloni's ack is added to patch 5.
  - The max_register value in simple_mfd_data is always used if
    it is non-zero, as requested by Lee Jones.
  - The global regmap_config_8r_8v structure is back to being
    const again.
  - A new function simple_regmap_config() has been added in patch 2
    to encapsulate the logic that determines what regmap_config
    structure will be used.
      - It uses regmap_config_8r_8v if simple_mfd_data is not supplied
        for some reason.
      - It uses regmap_config_8r_8v if the simple_mfd_data defines
        neither regmap_config nor max_register.
      - Otherwise, it dynamically allocates a regmap_config structure.
        If simple_mfd_data refers to a regmap_config structure, it is
	copied into the allocated struct; otherwise regmap_config_8r_8v
	is copied.
      - Finally, if the simple_mfd_data structure provides a non-zero
        max_register value, it is used in the regmap_config.
  - A small duplicated comment in "simple-mfd-i2c.h" is removed.

  					-Alex

This series is available here:
  https://github.com/riscstar/linux/tree/outgoing/pmic-v9

Between version 8 and version 9:
  - The max_config value is always used if it is provided with the
    simple_mfd_data structure.
  - The regmap_config structure used is allocated dynamically if
    necessary; otherwise regmap_config_8r_8v is used.
  - A small duplicated comment is removed

Here is version 8 of this series:
  https://lore.kernel.org/lkml/20250710175107.1280221-1-elder@riscstar.com/

Between version 7 and version 8:
  - Change the global regmap_config to not be const in patch 2.

Here is version 7 of this series:
  https://lore.kernel.org/lkml/20250702213658.545163-1-elder@riscstar.com/

Between version 6 and version 7:
  - Revise patch 2 to preserve the option to provide a full regmap config

Here is version 6 of this series:
  https://lore.kernel.org/lkml/20250627142309.1444135-1-elder@riscstar.com/

Between version 5 and version 6:
  - Added Rob Herring's reviewed-by to patch 1
  - Add the simple MFD functionality suggested by Lee Jones
  - Update patch 3 (previously 2) accordingly

Here is version 5 of this series:
  https://lore.kernel.org/lkml/20250625164119.1068842-1-elder@riscstar.com/

Between version 4 and version 5:
  - Only check the seconds register for change when looping on read
  - Return without re-enabling the RTC if writing registers fails
  - If the RTC is disabled when reading, return an error

Here is version 4 of this series:
  https://lore.kernel.org/lkml/20250625164119.1068842-1-elder@riscstar.com/

More complete history is available at that link.


Alex Elder (8):
  dt-bindings: mfd: add support the SpacemiT P1 PMIC
  mfd: simple-mfd-i2c: specify max_register
  mfd: simple-mfd-i2c: add SpacemiT P1 support
  regulator: spacemit: support SpacemiT P1 regulators
  rtc: spacemit: support the SpacemiT P1 RTC
  riscv: dts: spacemit: enable the i2c8 adapter
  riscv: dts: spacemit: define fixed regulators
  riscv: dts: spacemit: define regulator constraints

 .../devicetree/bindings/mfd/spacemit,p1.yaml  |  86 +++++++++
 .../boot/dts/spacemit/k1-bananapi-f3.dts      | 138 +++++++++++++++
 arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi  |   7 +
 arch/riscv/boot/dts/spacemit/k1.dtsi          |  11 ++
 drivers/mfd/Kconfig                           |  11 ++
 drivers/mfd/simple-mfd-i2c.c                  |  50 +++++-
 drivers/mfd/simple-mfd-i2c.h                  |   5 +-
 drivers/regulator/Kconfig                     |  12 ++
 drivers/regulator/Makefile                    |   1 +
 drivers/regulator/spacemit-p1.c               | 157 ++++++++++++++++
 drivers/rtc/Kconfig                           |  10 ++
 drivers/rtc/Makefile                          |   1 +
 drivers/rtc/rtc-spacemit-p1.c                 | 167 ++++++++++++++++++
 13 files changed, 647 insertions(+), 9 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mfd/spacemit,p1.yaml
 create mode 100644 drivers/regulator/spacemit-p1.c
 create mode 100644 drivers/rtc/rtc-spacemit-p1.c


base-commit: 9ee814bd78e315e4551223ca7548dd3f6bdcf1ae
-- 
2.43.0

[PATCH v9 1/8] dt-bindings: mfd: add support the SpacemiT P1 PMIC

[Alex Elder]

Enable the SpacemiT P1, which is an I2C-controlled PMIC.  Initially
only the RTC and regulators will be supported.

Signed-off-by: Alex Elder <elder@riscstar.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
---
 .../devicetree/bindings/mfd/spacemit,p1.yaml  | 86 +++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/spacemit,p1.yaml

diff --git a/Documentation/devicetree/bindings/mfd/spacemit,p1.yaml b/Documentation/devicetree/bindings/mfd/spacemit,p1.yaml
new file mode 100644
index 0000000000000..5cc34d4934b54
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/spacemit,p1.yaml
@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/spacemit,p1.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SpacemiT P1 Power Management Integrated Circuit
+
+maintainers:
+  - Troy Mitchell <troymitchell988@gmail.com>
+
+description:
+  P1 is an I2C-controlled PMIC produced by SpacemiT.  It implements six
+  constant-on-time buck converters and twelve low-dropout regulators.
+  It also contains a load switch, watchdog timer, real-time clock, eight
+  12-bit ADC channels, and six GPIOs.  Additional details are available
+  in the "Power Stone/P1" section at the following link.
+    https://developer.spacemit.com/documentation
+
+properties:
+  compatible:
+    const: spacemit,p1
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  vin-supply:
+    description: Input supply phandle.
+
+  regulators:
+    type: object
+
+    patternProperties:
+      "^(buck[1-6]|aldo[1-4]|dldo[1-7])$":
+        type: object
+        $ref: /schemas/regulator/regulator.yaml#
+        unevaluatedProperties: false
+
+    unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        pmic@41 {
+            compatible = "spacemit,p1";
+            reg = <0x41>;
+            interrupts = <64>;
+
+            regulators {
+                buck1 {
+                    regulator-name = "buck1";
+                    regulator-min-microvolt = <500000>;
+                    regulator-max-microvolt = <3450000>;
+                    regulator-ramp-delay = <5000>;
+                    regulator-always-on;
+                };
+
+                aldo1 {
+                    regulator-name = "aldo1";
+                    regulator-min-microvolt = <500000>;
+                    regulator-max-microvolt = <3400000>;
+                    regulator-boot-on;
+                };
+
+                dldo1 {
+                    regulator-name = "dldo1";
+                    regulator-min-microvolt = <500000>;
+                    regulator-max-microvolt = <3400000>;
+                    regulator-boot-on;
+                };
+            };
+        };
+    };
-- 
2.43.0

[PATCH v9 2/8] mfd: simple-mfd-i2c: specify max_register

[Alex Elder]

All devices supported by simple MFD use the same 8-bit register 8-bit
value regmap configuration.  There is an option available for a device
to specify a custom configuration, but no existing device uses it.

Rather than requiring a "full" regmap configuration to be provided to
change only the max_register value, Lee Jones suggested allowing
max_register to be specified in the simple_mfd_data structure.  The
8-bit register 8-bit configuration is still used by default, but
max_register is also applied if it is non-zero.

If both regmap_config and max_register are provided, the max_register
field in the regmap_config structure is ignored.

Signed-off-by: Alex Elder <elder@riscstar.com>
Suggested-by: Lee Jones <lee@kernel.org>
---
v9: - max_register takes precedence over regmap_config in simple_mfd_data
    - New function simple_regmap_config() encapsulates providing config
    - simple_regmap_config() allocates a regmap_config if necessary
    - A small duplicated comment is removed in "simple-mfd-i2c.h"

 drivers/mfd/simple-mfd-i2c.c | 38 +++++++++++++++++++++++++++++++-----
 drivers/mfd/simple-mfd-i2c.h |  5 +----
 2 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/drivers/mfd/simple-mfd-i2c.c b/drivers/mfd/simple-mfd-i2c.c
index 22159913bea03..f3ba79c112d4e 100644
--- a/drivers/mfd/simple-mfd-i2c.c
+++ b/drivers/mfd/simple-mfd-i2c.c
@@ -29,6 +29,36 @@ static const struct regmap_config regmap_config_8r_8v = {
 	.val_bits = 8,
 };
 
+/*
+ * Determine regmap config to use.  If no regmap_config is provided,
+ * regmap_config_8r_8v is used.  If max_register is specified it is
+ * (also) used, whether or not regmap_config is provided.
+ */
+static const struct regmap_config *
+simple_regmap_config(struct device *dev, const struct simple_mfd_data *data)
+{
+	struct regmap_config *regmap_config;
+
+	if (!data)
+		return &regmap_config_8r_8v;
+
+	if (data->regmap_config && !data->max_register)
+		return data->regmap_config;
+
+	regmap_config = devm_kzalloc(dev, sizeof(*regmap_config), GFP_KERNEL);
+	if (!regmap_config)
+		return NULL;
+
+	if (data->regmap_config)
+		*regmap_config = *data->regmap_config;
+	else
+		*regmap_config = regmap_config_8r_8v;
+	if (data->max_register)
+		regmap_config->max_register = data->max_register;
+
+	return regmap_config;
+}
+
 static int simple_mfd_i2c_probe(struct i2c_client *i2c)
 {
 	const struct simple_mfd_data *simple_mfd_data;
@@ -38,11 +68,9 @@ static int simple_mfd_i2c_probe(struct i2c_client *i2c)
 
 	simple_mfd_data = device_get_match_data(&i2c->dev);
 
-	/* If no regmap_config is specified, use the default 8reg and 8val bits */
-	if (!simple_mfd_data || !simple_mfd_data->regmap_config)
-		regmap_config = &regmap_config_8r_8v;
-	else
-		regmap_config = simple_mfd_data->regmap_config;
+	regmap_config = simple_regmap_config(&i2c->dev, simple_mfd_data);
+	if (!regmap_config)
+		return -ENOMEM;
 
 	regmap = devm_regmap_init_i2c(i2c, regmap_config);
 	if (IS_ERR(regmap))
diff --git a/drivers/mfd/simple-mfd-i2c.h b/drivers/mfd/simple-mfd-i2c.h
index 7cb2bdd347d97..6fa36b3d7a217 100644
--- a/drivers/mfd/simple-mfd-i2c.h
+++ b/drivers/mfd/simple-mfd-i2c.h
@@ -8,10 +8,6 @@
  * shared by all sub-devices.  Children can use their parent's device structure
  * (dev.parent) in order to reference it.
  *
- * This driver creates a single register map with the intention for it to be
- * shared by all sub-devices.  Children can use their parent's device structure
- * (dev.parent) in order to reference it.
- *
  * Once the register map has been successfully initialised, any sub-devices
  * represented by child nodes in Device Tree or via the MFD cells in the
  * associated C file will be subsequently registered.
@@ -25,6 +21,7 @@
 
 struct simple_mfd_data {
 	const struct regmap_config *regmap_config;
+	unsigned int max_register;
 	const struct mfd_cell *mfd_cell;
 	size_t mfd_cell_size;
 };
-- 
2.43.0

[PATCH v9 3/8] mfd: simple-mfd-i2c: add SpacemiT P1 support

[Alex Elder]

Enable support for the RTC and regulators found in the SpacemiT P1
PMIC.  Support is implemented by the simple I2C MFD driver.

The P1 PMIC is normally implemented with the SpacemiT K1 SoC.  This
PMIC provides 6 buck converters and 12 LDO regulators.  It also
implements a switch, watchdog timer, real-time clock, and more.
Initially its RTC and regulators are supported.

Signed-off-by: Alex Elder <elder@riscstar.com>
---
 drivers/mfd/Kconfig          | 11 +++++++++++
 drivers/mfd/simple-mfd-i2c.c | 12 ++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 0ea3a97bb93d1..21b117eddfea4 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1182,6 +1182,17 @@ config MFD_QCOM_RPM
 	  Say M here if you want to include support for the Qualcomm RPM as a
 	  module. This will build a module called "qcom_rpm".
 
+config MFD_SPACEMIT_P1
+	tristate "SpacemiT P1 PMIC"
+	depends on I2C
+	select MFD_SIMPLE_MFD_I2C
+	help
+	  This option supports the I2C-based SpacemiT P1 PMIC, which
+	  contains regulators, a power switch, GPIOs, an RTC, and more.
+	  This option is selected when any of the supported sub-devices
+	  is configured.  The basic functionality is implemented by the
+	  simple MFD I2C driver.
+
 config MFD_SPMI_PMIC
 	tristate "Qualcomm SPMI PMICs"
 	depends on ARCH_QCOM || COMPILE_TEST
diff --git a/drivers/mfd/simple-mfd-i2c.c b/drivers/mfd/simple-mfd-i2c.c
index f3ba79c112d4e..fd5d7b60433fe 100644
--- a/drivers/mfd/simple-mfd-i2c.c
+++ b/drivers/mfd/simple-mfd-i2c.c
@@ -121,12 +121,24 @@ static const struct simple_mfd_data maxim_mon_max77705 = {
 	.mfd_cell_size = ARRAY_SIZE(max77705_sensor_cells),
 };
 
+static const struct mfd_cell spacemit_p1_cells[] = {
+	{ .name = "spacemit-p1-regulator", },
+	{ .name = "spacemit-p1-rtc", },
+};
+
+static const struct simple_mfd_data spacemit_p1 = {
+	.mfd_cell = spacemit_p1_cells,
+	.mfd_cell_size = ARRAY_SIZE(spacemit_p1_cells),
+	.max_register = 0xaa,
+};
+
 static const struct of_device_id simple_mfd_i2c_of_match[] = {
 	{ .compatible = "kontron,sl28cpld" },
 	{ .compatible = "silergy,sy7636a", .data = &silergy_sy7636a},
 	{ .compatible = "maxim,max5970", .data = &maxim_max5970},
 	{ .compatible = "maxim,max5978", .data = &maxim_max5970},
 	{ .compatible = "maxim,max77705-battery", .data = &maxim_mon_max77705},
+	{ .compatible = "spacemit,p1", .data = &spacemit_p1, },
 	{}
 };
 MODULE_DEVICE_TABLE(of, simple_mfd_i2c_of_match);
-- 
2.43.0

[PATCH v9 4/8] regulator: spacemit: support SpacemiT P1 regulators

[Alex Elder]

Add support for the regulators found in the SpacemiT P1 PMIC.  This
PMIC provides 6 buck converters and 12 LDO regulators.

The PMIC is implemented as a multi-function device.  These regulators
are probed based on this driver being named in a MFD cell in the simple
MFD I2C driver.

Signed-off-by: Alex Elder <elder@riscstar.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
 drivers/regulator/Kconfig       |  12 +++
 drivers/regulator/Makefile      |   1 +
 drivers/regulator/spacemit-p1.c | 157 ++++++++++++++++++++++++++++++++
 3 files changed, 170 insertions(+)
 create mode 100644 drivers/regulator/spacemit-p1.c

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 7423954153b07..3e7feeebf8aca 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -1395,6 +1395,18 @@ config REGULATOR_SLG51000
 	  The SLG51000 is seven compact and customizable low dropout
 	  regulators.
 
+config REGULATOR_SPACEMIT_P1
+	tristate "SpacemiT P1 regulators"
+	depends on ARCH_SPACEMIT || COMPILE_TEST
+	select MFD_SPACEMIT_P1
+	default ARCH_SPACEMIT
+	help
+	  Enable support for regulators implemented by the SpacemiT P1
+	  power controller.  The P1 implements 6 high-efficiency buck
+	  converters and 12 programmable LDO regulators.  To compile this
+	  driver as a module, choose M here.  The module will be called
+	  "spacemit-pmic".
+
 config REGULATOR_STM32_BOOSTER
 	tristate "STMicroelectronics STM32 BOOSTER"
 	depends on ARCH_STM32 || COMPILE_TEST
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index be98b29d6675d..278f5b8d1c7d7 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -162,6 +162,7 @@ obj-$(CONFIG_REGULATOR_S5M8767) += s5m8767.o
 obj-$(CONFIG_REGULATOR_SC2731) += sc2731-regulator.o
 obj-$(CONFIG_REGULATOR_SKY81452) += sky81452-regulator.o
 obj-$(CONFIG_REGULATOR_SLG51000) += slg51000-regulator.o
+obj-$(CONFIG_REGULATOR_SPACEMIT_P1) += spacemit-p1.o
 obj-$(CONFIG_REGULATOR_STM32_BOOSTER) += stm32-booster.o
 obj-$(CONFIG_REGULATOR_STM32_VREFBUF) += stm32-vrefbuf.o
 obj-$(CONFIG_REGULATOR_STM32_PWR) += stm32-pwr.o
diff --git a/drivers/regulator/spacemit-p1.c b/drivers/regulator/spacemit-p1.c
new file mode 100644
index 0000000000000..d437e6738ea1e
--- /dev/null
+++ b/drivers/regulator/spacemit-p1.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for regulators found in the SpacemiT P1 PMIC
+ *
+ * Copyright (C) 2025 by RISCstar Solutions Corporation.  All rights reserved.
+ * Derived from code from SpacemiT.
+ *	Copyright (c) 2023, SPACEMIT Co., Ltd
+ */
+
+#include <linux/array_size.h>
+#include <linux/bits.h>
+#include <linux/device.h>
+#include <linux/linear_range.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+
+#define MOD_NAME	"spacemit-p1-regulator"
+
+enum p1_regulator_id {
+	P1_BUCK1,
+	P1_BUCK2,
+	P1_BUCK3,
+	P1_BUCK4,
+	P1_BUCK5,
+	P1_BUCK6,
+
+	P1_ALDO1,
+	P1_ALDO2,
+	P1_ALDO3,
+	P1_ALDO4,
+
+	P1_DLDO1,
+	P1_DLDO2,
+	P1_DLDO3,
+	P1_DLDO4,
+	P1_DLDO5,
+	P1_DLDO6,
+	P1_DLDO7,
+};
+
+static const struct regulator_ops p1_regulator_ops = {
+	.list_voltage		= regulator_list_voltage_linear_range,
+	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
+	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
+	.set_voltage_time_sel   = regulator_set_voltage_time_sel,
+	.enable			= regulator_enable_regmap,
+	.disable		= regulator_disable_regmap,
+	.is_enabled		= regulator_is_enabled_regmap,
+};
+
+/* Selector value 255 can be used to disable the buck converter on sleep */
+static const struct linear_range p1_buck_ranges[] = {
+	REGULATOR_LINEAR_RANGE(500000, 0, 170, 5000),
+	REGULATOR_LINEAR_RANGE(1375000, 171, 254, 25000),
+};
+
+/* Selector value 0 can be used for suspend */
+static const struct linear_range p1_ldo_ranges[] = {
+	REGULATOR_LINEAR_RANGE(500000, 11, 127, 25000),
+};
+
+/* These define the voltage selector field for buck and LDO regulators */
+#define BUCK_MASK		GENMASK(7, 0)
+#define LDO_MASK		GENMASK(6, 0)
+
+#define P1_ID(_TYPE, _n)	P1_ ## _TYPE ## _n
+#define P1_ENABLE_REG(_off, _n)	((_off) + 3 * ((_n) - 1))
+
+#define P1_REG_DESC(_TYPE, _type, _n, _s, _off, _mask, _nv, _ranges)	\
+	{								\
+		.name			= #_type #_n,			\
+		.supply_name		= _s,				\
+		.of_match		= of_match_ptr(#_type #_n),	\
+		.regulators_node	= of_match_ptr("regulators"),	\
+		.id			= P1_ID(_TYPE, _n),		\
+		.n_voltages		= _nv,				\
+		.ops			= &p1_regulator_ops,		\
+		.owner			= THIS_MODULE,			\
+		.linear_ranges		= _ranges,			\
+		.n_linear_ranges	= ARRAY_SIZE(_ranges),		\
+		.vsel_reg		= P1_ENABLE_REG(_off, _n) + 1,	\
+		.vsel_mask		= _mask,			\
+		.enable_reg		= P1_ENABLE_REG(_off, _n),	\
+		.enable_mask		= BIT(0),			\
+	}
+
+#define P1_BUCK_DESC(_n) \
+	P1_REG_DESC(BUCK, buck, _n, "vcc", 0x47, BUCK_MASK, 254, p1_buck_ranges)
+
+#define P1_ALDO_DESC(_n) \
+	P1_REG_DESC(ALDO, aldo, _n, "vcc", 0x5b, LDO_MASK, 117, p1_ldo_ranges)
+
+#define P1_DLDO_DESC(_n) \
+	P1_REG_DESC(DLDO, dldo, _n, "buck5", 0x67, LDO_MASK, 117, p1_ldo_ranges)
+
+static const struct regulator_desc p1_regulator_desc[] = {
+	P1_BUCK_DESC(1),
+	P1_BUCK_DESC(2),
+	P1_BUCK_DESC(3),
+	P1_BUCK_DESC(4),
+	P1_BUCK_DESC(5),
+	P1_BUCK_DESC(6),
+
+	P1_ALDO_DESC(1),
+	P1_ALDO_DESC(2),
+	P1_ALDO_DESC(3),
+	P1_ALDO_DESC(4),
+
+	P1_DLDO_DESC(1),
+	P1_DLDO_DESC(2),
+	P1_DLDO_DESC(3),
+	P1_DLDO_DESC(4),
+	P1_DLDO_DESC(5),
+	P1_DLDO_DESC(6),
+	P1_DLDO_DESC(7),
+};
+
+static int p1_regulator_probe(struct platform_device *pdev)
+{
+	struct regulator_config config = { };
+	struct device *dev = &pdev->dev;
+	u32 i;
+
+	/*
+	 * The parent device (PMIC) owns the regmap.  Since we don't
+	 * provide one in the config structure, that one will be used.
+	 */
+	config.dev = dev->parent;
+
+	for (i = 0; i < ARRAY_SIZE(p1_regulator_desc); i++) {
+		const struct regulator_desc *desc = &p1_regulator_desc[i];
+		struct regulator_dev *rdev;
+
+		rdev = devm_regulator_register(dev, desc, &config);
+		if (IS_ERR(rdev))
+			return dev_err_probe(dev, PTR_ERR(rdev),
+					     "error registering regulator %s\n",
+					     desc->name);
+	}
+
+	return 0;
+}
+
+static struct platform_driver p1_regulator_driver = {
+	.probe = p1_regulator_probe,
+	.driver = {
+		.name = MOD_NAME,
+	},
+};
+
+module_platform_driver(p1_regulator_driver);
+
+MODULE_DESCRIPTION("SpacemiT P1 regulator driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" MOD_NAME);
-- 
2.43.0

[PATCH v9 5/8] rtc: spacemit: support the SpacemiT P1 RTC

[Alex Elder]

Add support for the RTC found in the SpacemiT P1 PMIC.  Initially
only setting and reading the time are supported.

The PMIC is implemented as a multi-function device.  This RTC is
probed based on this driver being named in a MFD cell in the simple
MFD I2C driver.

Signed-off-by: Alex Elder <elder@riscstar.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
v9: - Added Alexandre Belloni's Acked-by tag

 drivers/rtc/Kconfig           |  10 ++
 drivers/rtc/Makefile          |   1 +
 drivers/rtc/rtc-spacemit-p1.c | 167 ++++++++++++++++++++++++++++++++++
 3 files changed, 178 insertions(+)
 create mode 100644 drivers/rtc/rtc-spacemit-p1.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 64f6e9756aff4..31d355b103d43 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -406,6 +406,16 @@ config RTC_DRV_MAX77686
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-max77686.
 
+config RTC_DRV_SPACEMIT_P1
+	tristate "SpacemiT P1 RTC"
+	depends on ARCH_SPACEMIT || COMPILE_TEST
+	select MFD_SPACEMIT_P1
+	default ARCH_SPACEMIT
+	help
+	  Enable support for the RTC function in the SpacemiT P1 PMIC.
+	  This driver can also be built as a module, which will be called
+	  "spacemit-p1-rtc".
+
 config RTC_DRV_NCT3018Y
 	tristate "Nuvoton NCT3018Y"
 	depends on OF
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 789bddfea99d8..f41fdb4fabae9 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -171,6 +171,7 @@ obj-$(CONFIG_RTC_DRV_SD2405AL)	+= rtc-sd2405al.o
 obj-$(CONFIG_RTC_DRV_SD3078)	+= rtc-sd3078.o
 obj-$(CONFIG_RTC_DRV_SH)	+= rtc-sh.o
 obj-$(CONFIG_RTC_DRV_SNVS)	+= rtc-snvs.o
+obj-$(CONFIG_RTC_DRV_SPACEMIT_P1)	+= rtc-spacemit-p1.o
 obj-$(CONFIG_RTC_DRV_SPEAR)	+= rtc-spear.o
 obj-$(CONFIG_RTC_DRV_STARFIRE)	+= rtc-starfire.o
 obj-$(CONFIG_RTC_DRV_STK17TA8)	+= rtc-stk17ta8.o
diff --git a/drivers/rtc/rtc-spacemit-p1.c b/drivers/rtc/rtc-spacemit-p1.c
new file mode 100644
index 0000000000000..43ab62494bb4b
--- /dev/null
+++ b/drivers/rtc/rtc-spacemit-p1.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the RTC found in the SpacemiT P1 PMIC
+ *
+ * Copyright (C) 2025 by RISCstar Solutions Corporation.  All rights reserved.
+ */
+
+#include <linux/bits.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+
+#define MOD_NAME	"spacemit-p1-rtc"
+
+/*
+ * Six consecutive 1-byte registers hold the seconds, minutes, hours,
+ * day-of-month, month, and year (respectively).
+ *
+ * The range of values in these registers is:
+ *    seconds	0-59
+ *    minutes	0-59
+ *    hours	0-59
+ *    day	0-30 (struct tm is 1-31)
+ *    month	0-11
+ *    year	years since 2000 (struct tm is since 1900)
+ *
+ * Note that the day and month must be converted after reading and
+ * before writing.
+ */
+#define RTC_TIME		0x0d	/* Offset of the seconds register */
+
+#define RTC_CTRL		0x1d
+#define RTC_EN		BIT(2)
+
+/* Number of attempts to read a consistent time stamp before giving up */
+#define RTC_READ_TRIES		20	/* At least 1 */
+
+struct p1_rtc {
+	struct regmap *regmap;
+	struct rtc_device *rtc;
+};
+
+/*
+ * The P1 hardware documentation states that the register values are
+ * latched to ensure a consistent time snapshot within the registers,
+ * but these are in fact unstable due to a bug in the hardware design.
+ * So we loop until we get two identical readings.
+ */
+static int p1_rtc_read_time(struct device *dev, struct rtc_time *t)
+{
+	struct p1_rtc *p1 = dev_get_drvdata(dev);
+	struct regmap *regmap = p1->regmap;
+	u32 count = RTC_READ_TRIES;
+	u8 seconds;
+	u8 time[6];
+	int ret;
+
+	if (!regmap_test_bits(regmap, RTC_CTRL, RTC_EN))
+		return -EINVAL;		/* RTC is disabled */
+
+	ret = regmap_bulk_read(regmap, RTC_TIME, time, sizeof(time));
+	if (ret)
+		return ret;
+
+	do {
+		seconds = time[0];
+		ret = regmap_bulk_read(regmap, RTC_TIME, time, sizeof(time));
+		if (ret)
+			return ret;
+	} while (time[0] != seconds && --count);
+
+	if (!count)
+		return -EIO;		/* Unable to get a consistent result */
+
+	t->tm_sec = time[0] & GENMASK(5, 0);
+	t->tm_min = time[1] & GENMASK(5, 0);
+	t->tm_hour = time[2] & GENMASK(4, 0);
+	t->tm_mday = (time[3] & GENMASK(4, 0)) + 1;
+	t->tm_mon = time[4] & GENMASK(3, 0);
+	t->tm_year = (time[5] & GENMASK(5, 0)) + 100;
+
+	return 0;
+}
+
+/*
+ * The P1 hardware documentation states that values in the registers are
+ * latched so when written they represent a consistent time snapshot.
+ * Nevertheless, this is not guaranteed by the implementation, so we must
+ * disable the RTC while updating it.
+ */
+static int p1_rtc_set_time(struct device *dev, struct rtc_time *t)
+{
+	struct p1_rtc *p1 = dev_get_drvdata(dev);
+	struct regmap *regmap = p1->regmap;
+	u8 time[6];
+	int ret;
+
+	time[0] = t->tm_sec;
+	time[1] = t->tm_min;
+	time[2] = t->tm_hour;
+	time[3] = t->tm_mday - 1;
+	time[4] = t->tm_mon;
+	time[5] = t->tm_year - 100;
+
+	/* Disable the RTC to update; re-enable again when done */
+	ret = regmap_clear_bits(regmap, RTC_CTRL, RTC_EN);
+	if (ret)
+		return ret;
+
+	/* If something goes wrong, leave the RTC disabled */
+	ret = regmap_bulk_write(regmap, RTC_TIME, time, sizeof(time));
+	if (ret)
+		return ret;
+
+	return regmap_set_bits(regmap, RTC_CTRL, RTC_EN);
+}
+
+static const struct rtc_class_ops p1_rtc_class_ops = {
+	.read_time = p1_rtc_read_time,
+	.set_time = p1_rtc_set_time,
+};
+
+static int p1_rtc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rtc_device *rtc;
+	struct p1_rtc *p1;
+
+	p1 = devm_kzalloc(dev, sizeof(*p1), GFP_KERNEL);
+	if (!p1)
+		return -ENOMEM;
+	dev_set_drvdata(dev, p1);
+
+	p1->regmap = dev_get_regmap(dev->parent, NULL);
+	if (!p1->regmap)
+		return dev_err_probe(dev, -ENODEV, "failed to get regmap\n");
+
+	rtc = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rtc))
+		return dev_err_probe(dev, PTR_ERR(rtc),
+				     "error allocating device\n");
+	p1->rtc = rtc;
+
+	rtc->ops = &p1_rtc_class_ops;
+	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rtc->range_max = RTC_TIMESTAMP_END_2063;
+
+	clear_bit(RTC_FEATURE_ALARM, rtc->features);
+	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
+
+	return devm_rtc_register_device(rtc);
+}
+
+static struct platform_driver p1_rtc_driver = {
+	.probe = p1_rtc_probe,
+	.driver = {
+		.name = MOD_NAME,
+	},
+};
+
+module_platform_driver(p1_rtc_driver);
+
+MODULE_DESCRIPTION("SpacemiT P1 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" MOD_NAME);
-- 
2.43.0

[PATCH v9 6/8] riscv: dts: spacemit: enable the i2c8 adapter

[Alex Elder]

Define properties for the I2C adapter that provides access to the
SpacemiT P1 PMIC.  Enable this adapter on the Banana Pi BPI-F3.

Signed-off-by: Alex Elder <elder@riscstar.com>
---
 arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts | 15 +++++++++++++++
 arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi    |  7 +++++++
 arch/riscv/boot/dts/spacemit/k1.dtsi            | 11 +++++++++++
 3 files changed, 33 insertions(+)

diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
index fe22c747c5012..7c9f91c88e01a 100644
--- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
@@ -40,6 +40,21 @@ &emmc {
 	status = "okay";
 };
 
+&i2c8 {
+	pinctrl-0 = <&i2c8_cfg>;
+	pinctrl-names = "default";
+	#address-cells = <1>;
+	#size-cells = <0>;
+	status = "okay";
+
+	pmic@41 {
+		compatible = "spacemit,p1";
+		reg = <0x41>;
+		interrupts = <64>;
+		status = "okay";
+	};
+};
+
 &uart0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&uart0_2_cfg>;
diff --git a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
index 3810557374228..96d7a46d4bf77 100644
--- a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
+++ b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
@@ -11,6 +11,13 @@
 #define K1_GPIO(x)	(x / 32) (x % 32)
 
 &pinctrl {
+	i2c8_cfg: i2c8-cfg {
+		i2c8-0-pins {
+			pinmux = <K1_PADCONF(93, 0)>,	/* PWR_SCL */
+				 <K1_PADCONF(94, 0)>;	/* PWR_SDA */
+		};
+	};
+
 	uart0_2_cfg: uart0-2-cfg {
 		uart0-2-pins {
 			pinmux = <K1_PADCONF(68, 2)>,
diff --git a/arch/riscv/boot/dts/spacemit/k1.dtsi b/arch/riscv/boot/dts/spacemit/k1.dtsi
index abde8bb07c95c..2a5a132d5a774 100644
--- a/arch/riscv/boot/dts/spacemit/k1.dtsi
+++ b/arch/riscv/boot/dts/spacemit/k1.dtsi
@@ -459,6 +459,17 @@ pwm7: pwm@d401bc00 {
 			status = "disabled";
 		};
 
+		i2c8: i2c@d401d800 {
+			compatible = "spacemit,k1-i2c";
+			reg = <0x0 0xd401d800 0x0 0x38>;
+			interrupts = <19>;
+			clocks = <&syscon_apbc CLK_TWSI8>,
+				 <&syscon_apbc CLK_TWSI8_BUS>;
+			clock-names = "func", "bus";
+			clock-frequency = <400000>;
+			status = "disabled";
+		};
+
 		pinctrl: pinctrl@d401e000 {
 			compatible = "spacemit,k1-pinctrl";
 			reg = <0x0 0xd401e000 0x0 0x400>;
-- 
2.43.0

[PATCH v9 7/8] riscv: dts: spacemit: define fixed regulators

[Alex Elder]

Define the DC power input and the 4v power as fixed supplies in the
Banana Pi BPI-F3.

Signed-off-by: Alex Elder <elder@riscstar.com>
---
 .../boot/dts/spacemit/k1-bananapi-f3.dts      | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
index 7c9f91c88e01a..a1c184b814262 100644
--- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
@@ -28,6 +28,25 @@ led1 {
 			default-state = "on";
 		};
 	};
+
+	reg_dc_in: dc-in-12v {
+		compatible = "regulator-fixed";
+		regulator-name = "dc_in_12v";
+		regulator-min-microvolt = <12000000>;
+		regulator-max-microvolt = <12000000>;
+		regulator-boot-on;
+		regulator-always-on;
+	};
+
+	reg_vcc_4v: vcc-4v {
+		compatible = "regulator-fixed";
+		regulator-name = "vcc_4v";
+		regulator-min-microvolt = <4000000>;
+		regulator-max-microvolt = <4000000>;
+		regulator-boot-on;
+		regulator-always-on;
+		vin-supply = <&reg_dc_in>;
+	};
 };
 
 &emmc {
-- 
2.43.0

[PATCH v9 8/8] riscv: dts: spacemit: define regulator constraints

[Alex Elder]

Define basic constraints for the regulators in the SpacemiT P1 PMIC,
as implemented in the Banana Pi BPI-F3.

Signed-off-by: Alex Elder <elder@riscstar.com>
---
 .../boot/dts/spacemit/k1-bananapi-f3.dts      | 104 ++++++++++++++++++
 1 file changed, 104 insertions(+)

diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
index a1c184b814262..83907cc1d5ccf 100644
--- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
@@ -70,7 +70,111 @@ pmic@41 {
 		compatible = "spacemit,p1";
 		reg = <0x41>;
 		interrupts = <64>;
+		vin-supply = <&reg_vcc_4v>;
 		status = "okay";
+
+		regulators {
+			buck1 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3450000>;
+				regulator-ramp-delay = <5000>;
+				regulator-always-on;
+			};
+
+			buck2 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3450000>;
+				regulator-ramp-delay = <5000>;
+				regulator-always-on;
+			};
+
+			buck3 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <1800000>;
+				regulator-ramp-delay = <5000>;
+				regulator-always-on;
+			};
+
+			buck4 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3300000>;
+				regulator-ramp-delay = <5000>;
+				regulator-always-on;
+			};
+
+			buck5 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3450000>;
+				regulator-ramp-delay = <5000>;
+				regulator-always-on;
+			};
+
+			buck6 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3450000>;
+				regulator-ramp-delay = <5000>;
+				regulator-always-on;
+			};
+
+			aldo1 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3400000>;
+				regulator-boot-on;
+			};
+
+			aldo2 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3400000>;
+			};
+
+			aldo3 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3400000>;
+			};
+
+			aldo4 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3400000>;
+			};
+
+			dldo1 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3400000>;
+				regulator-boot-on;
+			};
+
+			dldo2 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3400000>;
+			};
+
+			dldo3 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3400000>;
+			};
+
+			dldo4 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3400000>;
+				regulator-always-on;
+			};
+
+			dldo5 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3400000>;
+			};
+
+			dldo6 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3400000>;
+				regulator-always-on;
+			};
+
+			dldo7 {
+				regulator-min-microvolt = <500000>;
+				regulator-max-microvolt = <3400000>;
+			};
+		};
 	};
 };
 
-- 
2.43.0

Re: [PATCH v9 6/8] riscv: dts: spacemit: enable the i2c8 adapter

[Yixun Lan]

Hi Alex,

On 15:25 Thu 24 Jul     , Alex Elder wrote:
> Define properties for the I2C adapter that provides access to the
> SpacemiT P1 PMIC.  Enable this adapter on the Banana Pi BPI-F3.
> 
> Signed-off-by: Alex Elder <elder@riscstar.com>
> ---
>  arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts | 15 +++++++++++++++
>  arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi    |  7 +++++++
>  arch/riscv/boot/dts/spacemit/k1.dtsi            | 11 +++++++++++
>  3 files changed, 33 insertions(+)
> 
> diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> index fe22c747c5012..7c9f91c88e01a 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
> @@ -40,6 +40,21 @@ &emmc {
>  	status = "okay";
>  };
>  
> +&i2c8 {
> +	pinctrl-0 = <&i2c8_cfg>;
> +	pinctrl-names = "default";
..
> +	#address-cells = <1>;
> +	#size-cells = <0>;
I think these two can be moved into dtsi, as they are
common and fixed properties for the i2c controller

> +	status = "okay";
> +
> +	pmic@41 {
> +		compatible = "spacemit,p1";
> +		reg = <0x41>;
> +		interrupts = <64>;
..
> +		status = "okay";
status property here can be dropped as enabled by default
> +	};
> +};
> +
>  &uart0 {
>  	pinctrl-names = "default";
>  	pinctrl-0 = <&uart0_2_cfg>;
> diff --git a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
> index 3810557374228..96d7a46d4bf77 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
> +++ b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
> @@ -11,6 +11,13 @@
>  #define K1_GPIO(x)	(x / 32) (x % 32)
>  
>  &pinctrl {
> +	i2c8_cfg: i2c8-cfg {
> +		i2c8-0-pins {
> +			pinmux = <K1_PADCONF(93, 0)>,	/* PWR_SCL */
> +				 <K1_PADCONF(94, 0)>;	/* PWR_SDA */
> +		};
> +	};
> +
>  	uart0_2_cfg: uart0-2-cfg {
>  		uart0-2-pins {
>  			pinmux = <K1_PADCONF(68, 2)>,
> diff --git a/arch/riscv/boot/dts/spacemit/k1.dtsi b/arch/riscv/boot/dts/spacemit/k1.dtsi
> index abde8bb07c95c..2a5a132d5a774 100644
> --- a/arch/riscv/boot/dts/spacemit/k1.dtsi
> +++ b/arch/riscv/boot/dts/spacemit/k1.dtsi
> @@ -459,6 +459,17 @@ pwm7: pwm@d401bc00 {
>  			status = "disabled";
>  		};
>  
> +		i2c8: i2c@d401d800 {
> +			compatible = "spacemit,k1-i2c";
> +			reg = <0x0 0xd401d800 0x0 0x38>;
..
> +			interrupts = <19>;
I'd suggest to move interrupts property after clock, see my similar
comment
https://lore.kernel.org/all/20250724121916-GYA748228@gentoo/

> +			clocks = <&syscon_apbc CLK_TWSI8>,
> +				 <&syscon_apbc CLK_TWSI8_BUS>;
> +			clock-names = "func", "bus";
> +			clock-frequency = <400000>;
> +			status = "disabled";
> +		};
> +
>  		pinctrl: pinctrl@d401e000 {
>  			compatible = "spacemit,k1-pinctrl";
>  			reg = <0x0 0xd401e000 0x0 0x400>;
> -- 
> 2.43.0
> 

-- 
Yixun Lan (dlan)

Re: [PATCH v9 6/8] riscv: dts: spacemit: enable the i2c8 adapter

[Alex Elder]

On 7/24/25 4:11 PM, Yixun Lan wrote:
> Hi Alex,
> 
> On 15:25 Thu 24 Jul     , Alex Elder wrote:
>> Define properties for the I2C adapter that provides access to the
>> SpacemiT P1 PMIC.  Enable this adapter on the Banana Pi BPI-F3.
>>
>> Signed-off-by: Alex Elder <elder@riscstar.com>
>> ---
>>   arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts | 15 +++++++++++++++
>>   arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi    |  7 +++++++
>>   arch/riscv/boot/dts/spacemit/k1.dtsi            | 11 +++++++++++
>>   3 files changed, 33 insertions(+)
>>
>> diff --git a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
>> index fe22c747c5012..7c9f91c88e01a 100644
>> --- a/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
>> +++ b/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dts
>> @@ -40,6 +40,21 @@ &emmc {
>>   	status = "okay";
>>   };
>>   
>> +&i2c8 {
>> +	pinctrl-0 = <&i2c8_cfg>;
>> +	pinctrl-names = "default";
> ..
>> +	#address-cells = <1>;
>> +	#size-cells = <0>;
> I think these two can be moved into dtsi, as they are
> common and fixed properties for the i2c controller

You're right.  I will update this in v10, which I will
send later today.  I'd like to hear from Lee before I
prepare that though.

>> +	status = "okay";
>> +
>> +	pmic@41 {
>> +		compatible = "spacemit,p1";
>> +		reg = <0x41>;
>> +		interrupts = <64>;
> ..
>> +		status = "okay";
> status property here can be dropped as enabled by default

OK.

>> +	};
>> +};
>> +
>>   &uart0 {
>>   	pinctrl-names = "default";
>>   	pinctrl-0 = <&uart0_2_cfg>;
>> diff --git a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
>> index 3810557374228..96d7a46d4bf77 100644
>> --- a/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
>> +++ b/arch/riscv/boot/dts/spacemit/k1-pinctrl.dtsi
>> @@ -11,6 +11,13 @@
>>   #define K1_GPIO(x)	(x / 32) (x % 32)
>>   
>>   &pinctrl {
>> +	i2c8_cfg: i2c8-cfg {
>> +		i2c8-0-pins {
>> +			pinmux = <K1_PADCONF(93, 0)>,	/* PWR_SCL */
>> +				 <K1_PADCONF(94, 0)>;	/* PWR_SDA */
>> +		};
>> +	};
>> +
>>   	uart0_2_cfg: uart0-2-cfg {
>>   		uart0-2-pins {
>>   			pinmux = <K1_PADCONF(68, 2)>,
>> diff --git a/arch/riscv/boot/dts/spacemit/k1.dtsi b/arch/riscv/boot/dts/spacemit/k1.dtsi
>> index abde8bb07c95c..2a5a132d5a774 100644
>> --- a/arch/riscv/boot/dts/spacemit/k1.dtsi
>> +++ b/arch/riscv/boot/dts/spacemit/k1.dtsi
>> @@ -459,6 +459,17 @@ pwm7: pwm@d401bc00 {
>>   			status = "disabled";
>>   		};
>>   
>> +		i2c8: i2c@d401d800 {
>> +			compatible = "spacemit,k1-i2c";
>> +			reg = <0x0 0xd401d800 0x0 0x38>;
> ..
>> +			interrupts = <19>;
> I'd suggest to move interrupts property after clock, see my similar
> comment
> https://lore.kernel.org/all/20250724121916-GYA748228@gentoo/

OK.

					-Alex

> 
>> +			clocks = <&syscon_apbc CLK_TWSI8>,
>> +				 <&syscon_apbc CLK_TWSI8_BUS>;
>> +			clock-names = "func", "bus";
>> +			clock-frequency = <400000>;
>> +			status = "disabled";
>> +		};
>> +
>>   		pinctrl: pinctrl@d401e000 {
>>   			compatible = "spacemit,k1-pinctrl";
>>   			reg = <0x0 0xd401e000 0x0 0x400>;
>> -- 
>> 2.43.0
>>
> 

Re: [PATCH v9 2/8] mfd: simple-mfd-i2c: specify max_register

[Alex Elder]

On 7/24/25 3:25 PM, Alex Elder wrote:
> All devices supported by simple MFD use the same 8-bit register 8-bit
> value regmap configuration.  There is an option available for a device
> to specify a custom configuration, but no existing device uses it.
> 
> Rather than requiring a "full" regmap configuration to be provided to
> change only the max_register value, Lee Jones suggested allowing
> max_register to be specified in the simple_mfd_data structure.  The
> 8-bit register 8-bit configuration is still used by default, but
> max_register is also applied if it is non-zero.
> 
> If both regmap_config and max_register are provided, the max_register
> field in the regmap_config structure is ignored.

It occurred to me this morning that the regmap_config structure
can be freed after the call to devm_regmap_init_i2c(), so I'm
going to add a function to free it (if it was dynamically
allocated).

					-Alex

> Signed-off-by: Alex Elder <elder@riscstar.com>
> Suggested-by: Lee Jones <lee@kernel.org>
> ---
> v9: - max_register takes precedence over regmap_config in simple_mfd_data
>      - New function simple_regmap_config() encapsulates providing config
>      - simple_regmap_config() allocates a regmap_config if necessary
>      - A small duplicated comment is removed in "simple-mfd-i2c.h"
> 
>   drivers/mfd/simple-mfd-i2c.c | 38 +++++++++++++++++++++++++++++++-----
>   drivers/mfd/simple-mfd-i2c.h |  5 +----
>   2 files changed, 34 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/mfd/simple-mfd-i2c.c b/drivers/mfd/simple-mfd-i2c.c
> index 22159913bea03..f3ba79c112d4e 100644
> --- a/drivers/mfd/simple-mfd-i2c.c
> +++ b/drivers/mfd/simple-mfd-i2c.c
> @@ -29,6 +29,36 @@ static const struct regmap_config regmap_config_8r_8v = {
>   	.val_bits = 8,
>   };
>   
> +/*
> + * Determine regmap config to use.  If no regmap_config is provided,
> + * regmap_config_8r_8v is used.  If max_register is specified it is
> + * (also) used, whether or not regmap_config is provided.
> + */
> +static const struct regmap_config *
> +simple_regmap_config(struct device *dev, const struct simple_mfd_data *data)
> +{
> +	struct regmap_config *regmap_config;
> +
> +	if (!data)
> +		return &regmap_config_8r_8v;
> +
> +	if (data->regmap_config && !data->max_register)
> +		return data->regmap_config;
> +
> +	regmap_config = devm_kzalloc(dev, sizeof(*regmap_config), GFP_KERNEL);
> +	if (!regmap_config)
> +		return NULL;
> +
> +	if (data->regmap_config)
> +		*regmap_config = *data->regmap_config;
> +	else
> +		*regmap_config = regmap_config_8r_8v;
> +	if (data->max_register)
> +		regmap_config->max_register = data->max_register;
> +
> +	return regmap_config;
> +}
> +
>   static int simple_mfd_i2c_probe(struct i2c_client *i2c)
>   {
>   	const struct simple_mfd_data *simple_mfd_data;
> @@ -38,11 +68,9 @@ static int simple_mfd_i2c_probe(struct i2c_client *i2c)
>   
>   	simple_mfd_data = device_get_match_data(&i2c->dev);
>   
> -	/* If no regmap_config is specified, use the default 8reg and 8val bits */
> -	if (!simple_mfd_data || !simple_mfd_data->regmap_config)
> -		regmap_config = &regmap_config_8r_8v;
> -	else
> -		regmap_config = simple_mfd_data->regmap_config;
> +	regmap_config = simple_regmap_config(&i2c->dev, simple_mfd_data);
> +	if (!regmap_config)
> +		return -ENOMEM;
>   
>   	regmap = devm_regmap_init_i2c(i2c, regmap_config);
>   	if (IS_ERR(regmap))
> diff --git a/drivers/mfd/simple-mfd-i2c.h b/drivers/mfd/simple-mfd-i2c.h
> index 7cb2bdd347d97..6fa36b3d7a217 100644
> --- a/drivers/mfd/simple-mfd-i2c.h
> +++ b/drivers/mfd/simple-mfd-i2c.h
> @@ -8,10 +8,6 @@
>    * shared by all sub-devices.  Children can use their parent's device structure
>    * (dev.parent) in order to reference it.
>    *
> - * This driver creates a single register map with the intention for it to be
> - * shared by all sub-devices.  Children can use their parent's device structure
> - * (dev.parent) in order to reference it.
> - *
>    * Once the register map has been successfully initialised, any sub-devices
>    * represented by child nodes in Device Tree or via the MFD cells in the
>    * associated C file will be subsequently registered.
> @@ -25,6 +21,7 @@
>   
>   struct simple_mfd_data {
>   	const struct regmap_config *regmap_config;
> +	unsigned int max_register;
>   	const struct mfd_cell *mfd_cell;
>   	size_t mfd_cell_size;
>   };