[PATCH v11 0/2] mfd: max597x: Add support for max597x

[PATCH v11 0/2] mfd: max597x: Add support for max597x

[Naresh Solanki]

max597x is multifunction device with hot swap controller, fault
protection & upto four indication leds.

max5978 has single hot swap controller whereas max5970 has two hot swap
controllers.

Changes in V11:
- Update description in DT
- Remove newline at end of file.
Changes in V10:
- Cleanup unused properties
- removed superfluous comments
- Update description for regulators property
- Fix typo
- Update 4 spaces indentation in example
Changes in V9:
- Update properties description
- update required property
Change in V8:
- Set additionalproperties to false
Change in V7:
- Update id
- Remove empty line
Changes in V6:
- Update missing vendor prefix
- Update indentation in example
Changes in V5:
- Fix dt schema error
Changes in V4:
- Add NULL entry for of_device_id
- Memory allocation check
Changes in V3:
- Address code review comment
Changes in V2:
- Update depends in Kconfig.

Marcello Sylvester Bauer (1):
  dt-bindings: mfd: Add MAX5970 and MAX5978

Patrick Rudolph (1):
  mfd: max597x: Add support for MAX5970 and MAX5978

 .../bindings/mfd/maxim,max5970.yaml           | 151 ++++++++++++++++++
 drivers/mfd/Kconfig                           |  12 ++
 drivers/mfd/Makefile                          |   1 +
 drivers/mfd/max597x.c                         |  93 +++++++++++
 include/linux/mfd/max597x.h                   | 101 ++++++++++++
 5 files changed, 358 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/maxim,max5970.yaml
 create mode 100644 drivers/mfd/max597x.c
 create mode 100644 include/linux/mfd/max597x.h


base-commit: 27fea302952d8c90cafbdbee96bafeca03544401
-- 
2.37.3

[PATCH v11 1/2] dt-bindings: mfd: Add MAX5970 and MAX5978

[Naresh Solanki]

From: Marcello Sylvester Bauer <sylv@sylv.io>

The MAX597x is a hot swap controller with configurable fault protection.
It also has 10bit ADC for current & voltage measurements.

Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
Co-developed-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Co-developed-by: Naresh Solanki <Naresh.Solanki@9elements.com>
Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
---
 .../bindings/mfd/maxim,max5970.yaml           | 151 ++++++++++++++++++
 1 file changed, 151 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/maxim,max5970.yaml

diff --git a/Documentation/devicetree/bindings/mfd/maxim,max5970.yaml b/Documentation/devicetree/bindings/mfd/maxim,max5970.yaml
new file mode 100644
index 000000000000..6ee269afdab2
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/maxim,max5970.yaml
@@ -0,0 +1,151 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/maxim,max5970.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Regulator for MAX5970 smart switch from Maxim Integrated.
+
+maintainers:
+  - Patrick Rudolph <patrick.rudolph@9elements.com>
+
+description: |
+  The smart switch provides no output regulation, but independent fault protection
+  and voltage and current sensing.
+  Programming is done through I2C bus.
+
+  Datasheets:
+    https://datasheets.maximintegrated.com/en/ds/MAX5970.pdf
+    https://datasheets.maximintegrated.com/en/ds/MAX5978.pdf
+
+properties:
+  compatible:
+    enum:
+      - maxim,max5970
+      - maxim,max5978
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  leds:
+    type: object
+    description:
+      Properties for four LEDS.
+
+    properties:
+      "#address-cells":
+        const: 1
+
+      "#size-cells":
+        const: 0
+
+    patternProperties:
+      "^led@[0-3]$":
+        $ref: /schemas/leds/common.yaml#
+        type: object
+
+    additionalProperties: false
+
+  vss1-supply:
+    description: Supply of the first channel.
+
+  vss2-supply:
+    description: Supply of the second channel.
+
+  regulators:
+    type: object
+    description:
+      Properties for both hot swap control/switch.
+
+    patternProperties:
+      "^sw[0-1]$":
+        $ref: /schemas/regulator/regulator.yaml#
+        type: object
+        properties:
+          shunt-resistor-micro-ohms:
+            description: |
+              The value of current sense resistor in microohms.
+
+        required:
+          - shunt-resistor-micro-ohms
+
+        unevaluatedProperties: false
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - regulators
+  - vss1-supply
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          enum:
+            - maxim,max5970
+    then:
+      required:
+        - vss2-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        regulator@3a {
+            compatible = "maxim,max5978";
+            reg = <0x3a>;
+            vss1-supply = <&p3v3>;
+
+            regulators {
+                sw0_ref_0: sw0 {
+                    shunt-resistor-micro-ohms = <12000>;
+                };
+            };
+
+            leds {
+                #address-cells = <1>;
+                #size-cells = <0>;
+                led@0 {
+                    reg = <0>;
+                    label = "led0";
+                    default-state = "on";
+                };
+                led@1 {
+                    reg = <1>;
+                    label = "led1";
+                    default-state = "on";
+                };
+            };
+        };
+    };
+
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        regulator@3a {
+            compatible = "maxim,max5970";
+            reg = <0x3a>;
+            vss1-supply = <&p3v3>;
+            vss2-supply = <&p5v>;
+
+            regulators {
+                sw0_ref_1: sw0 {
+                    shunt-resistor-micro-ohms = <12000>;
+                };
+                sw1_ref_1: sw1 {
+                    shunt-resistor-micro-ohms = <10000>;
+                };
+            };
+        };
+    };
+...
-- 
2.37.3

[PATCH v11 2/2] mfd: max597x: Add support for MAX5970 and MAX5978

[Naresh Solanki]

From: Patrick Rudolph <patrick.rudolph@9elements.com>

Implement a regulator driver with IRQ support for fault management.
Written against documentation [1] and [2] and tested on real hardware.

Every channel has its own regulator supplies nammed 'vss1-supply' and
'vss2-supply'. The regulator supply is used to determine the output
voltage, as the smart switch provides no output regulation.
The driver requires the 'shunt-resistor-micro-ohms' property to be
present in Device Tree to properly calculate current related
values.

Datasheet links:
1: https://datasheets.maximintegrated.com/en/ds/MAX5970.pdf
2: https://datasheets.maximintegrated.com/en/ds/MAX5978.pdf

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Co-developed-by: Marcello Sylvester Bauer <sylv@sylv.io>
Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
Co-developed-by: Naresh Solanki <Naresh.Solanki@9elements.com>
Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
---
 drivers/mfd/Kconfig         |  12 +++++
 drivers/mfd/Makefile        |   1 +
 drivers/mfd/max597x.c       |  93 +++++++++++++++++++++++++++++++++
 include/linux/mfd/max597x.h | 101 ++++++++++++++++++++++++++++++++++++
 4 files changed, 207 insertions(+)
 create mode 100644 drivers/mfd/max597x.c
 create mode 100644 include/linux/mfd/max597x.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 8b93856de432..416fe7986b7b 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -253,6 +253,18 @@ config MFD_MADERA_SPI
 	  Support for the Cirrus Logic Madera platform audio SoC
 	  core functionality controlled via SPI.
 
+config MFD_MAX597X
+	tristate "Maxim 597x Power Switch and Monitor"
+	depends on I2C
+	depends on OF
+	select MFD_CORE
+	select REGMAP_I2C
+	help
+	  This driver controls a Maxim 5970/5978 switch via I2C bus.
+	  The MAX5970/5978 is a smart switch with no output regulation, but
+	  fault protection and voltage and current monitoring capabilities.
+	  Also it supports upto 4 indication LEDs.
+
 config MFD_CS47L15
 	bool "Cirrus Logic CS47L15"
 	select PINCTRL_CS47L15
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 7ed3ef4a698c..819d711fa748 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -161,6 +161,7 @@ obj-$(CONFIG_MFD_DA9063)	+= da9063.o
 obj-$(CONFIG_MFD_DA9150)	+= da9150-core.o
 
 obj-$(CONFIG_MFD_MAX14577)	+= max14577.o
+obj-$(CONFIG_MFD_MAX597X)	+= max597x.o
 obj-$(CONFIG_MFD_MAX77620)	+= max77620.o
 obj-$(CONFIG_MFD_MAX77650)	+= max77650.o
 obj-$(CONFIG_MFD_MAX77686)	+= max77686.o
diff --git a/drivers/mfd/max597x.c b/drivers/mfd/max597x.c
new file mode 100644
index 000000000000..45838413f24a
--- /dev/null
+++ b/drivers/mfd/max597x.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Maxim MAX5970/MAX5978 Power Switch & Monitor
+ *
+ * Copyright (c) 2022 9elements GmbH
+ *
+ * Author: Patrick Rudolph <patrick.rudolph@9elements.com>
+ */
+
+#include <linux/i2c.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/max597x.h>
+#include <linux/regmap.h>
+
+static const struct regmap_config max597x_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = MAX_REGISTERS,
+};
+
+static const struct mfd_cell max597x_cells[] = {
+	{ .name = "max597x-regulator", },
+	{ .name = "max597x-iio", },
+	{ .name = "max597x-led", },
+};
+
+static int max597x_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
+{
+	struct max597x_data *ddata;
+	enum max597x_chip_type chip = id->driver_data;
+
+	ddata = devm_kzalloc(&i2c->dev, sizeof(*ddata),	GFP_KERNEL);
+	if (!ddata)
+		return -ENOMEM;
+
+	/*
+	 * Based on chip type, Initialize the number of switch. This is needed by
+	 * regulator & iio cells.
+	 */
+	switch (chip) {
+	case MAX597x_TYPE_MAX5970:
+		ddata->num_switches = MAX5970_NUM_SWITCHES;
+		break;
+	case MAX597x_TYPE_MAX5978:
+		ddata->num_switches = MAX5978_NUM_SWITCHES;
+		break;
+	}
+
+	ddata->regmap = devm_regmap_init_i2c(i2c, &max597x_regmap_config);
+	if (IS_ERR(ddata->regmap)) {
+		dev_err(&i2c->dev, "Failed to initialize regmap");
+		return PTR_ERR(ddata->regmap);
+	}
+
+	/* IRQ used by regulator cell */
+	ddata->irq = i2c->irq;
+	ddata->dev = &i2c->dev;
+	i2c_set_clientdata(i2c, ddata);
+
+	return devm_mfd_add_devices(ddata->dev, PLATFORM_DEVID_AUTO,
+				    max597x_cells, ARRAY_SIZE(max597x_cells),
+				    NULL, 0, NULL);
+}
+
+static const struct i2c_device_id max597x_table[] = {
+	{ .name = "max5970", MAX597x_TYPE_MAX5970 },
+	{ .name = "max5978", MAX597x_TYPE_MAX5978 },
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, max597x_table);
+
+static const struct of_device_id max597x_of_match[] = {
+	{ .compatible = "maxim,max5970" },
+	{ .compatible = "maxim,max5978" },
+	{}
+};
+
+MODULE_DEVICE_TABLE(of, max597x_of_match);
+
+static struct i2c_driver max597x_driver = {
+	.id_table = max597x_table,
+	.driver = {
+		  .name = "max597x",
+		  .of_match_table = of_match_ptr(max597x_of_match),
+		  },
+	.probe = max597x_probe,
+};
+module_i2c_driver(max597x_driver);
+
+MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
+MODULE_DESCRIPTION("MAX597X Power Switch and Monitor");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/max597x.h b/include/linux/mfd/max597x.h
new file mode 100644
index 000000000000..706eff9c50a4
--- /dev/null
+++ b/include/linux/mfd/max597x.h
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Maxim MAX5970/MAX5978 Power Switch & Monitor
+ *
+ * Copyright (c) 2022 9elements GmbH
+ *
+ * Author: Patrick Rudolph <patrick.rudolph@9elements.com>
+ */
+
+#ifndef MFD_MAX597X_H
+#define MFD_MAX597X_H
+
+#include <linux/device.h>
+#include <linux/regmap.h>
+
+#define MAX5970_NUM_SWITCHES 2
+#define MAX5978_NUM_SWITCHES 1
+#define MAX597X_NUM_LEDS     4
+
+enum max597x_chip_type {
+	MAX597x_TYPE_MAX5978 = 1,
+	MAX597x_TYPE_MAX5970,
+};
+
+#define MAX5970_REG_CURRENT_L(ch)		(0x01 + (ch) * 4)
+#define MAX5970_REG_CURRENT_H(ch)		(0x00 + (ch) * 4)
+#define MAX5970_REG_VOLTAGE_L(ch)		(0x03 + (ch) * 4)
+#define MAX5970_REG_VOLTAGE_H(ch)		(0x02 + (ch) * 4)
+#define MAX5970_REG_MON_RANGE			0x18
+#define  MAX5970_MON_MASK				0x3
+#define  MAX5970_MON(reg, ch)		(((reg) >> ((ch) * 2)) & MAX5970_MON_MASK)
+#define  MAX5970_MON_MAX_RANGE_UV		16000000
+
+#define MAX5970_REG_CH_UV_WARN_H(ch)	(0x1A + (ch) * 10)
+#define MAX5970_REG_CH_UV_WARN_L(ch)	(0x1B + (ch) * 10)
+#define MAX5970_REG_CH_UV_CRIT_H(ch)	(0x1C + (ch) * 10)
+#define MAX5970_REG_CH_UV_CRIT_L(ch)	(0x1D + (ch) * 10)
+#define MAX5970_REG_CH_OV_WARN_H(ch)	(0x1E + (ch) * 10)
+#define MAX5970_REG_CH_OV_WARN_L(ch)	(0x1F + (ch) * 10)
+#define MAX5970_REG_CH_OV_CRIT_H(ch)	(0x20 + (ch) * 10)
+#define MAX5970_REG_CH_OV_CRIT_L(ch)	(0x21 + (ch) * 10)
+
+#define  MAX5970_VAL2REG_H(x)			(((x) >> 2) & 0xFF)
+#define  MAX5970_VAL2REG_L(x)			((x) & 0x3)
+
+#define MAX5970_REG_DAC_FAST(ch)		(0x2E + (ch))
+
+#define MAX5970_FAST2SLOW_RATIO			200
+
+#define MAX5970_REG_STATUS0				0x31
+#define  MAX5970_CB_IFAULTF(ch)			(1 << (ch))
+#define  MAX5970_CB_IFAULTS(ch)			(1 << ((ch) + 4))
+
+#define MAX5970_REG_STATUS1				0x32
+#define  STATUS1_PROT_MASK				0x3
+#define  STATUS1_PROT(reg) \
+	(((reg) >> 6) & STATUS1_PROT_MASK)
+#define  STATUS1_PROT_SHUTDOWN			0
+#define  STATUS1_PROT_CLEAR_PG			1
+#define  STATUS1_PROT_ALERT_ONLY		2
+
+#define MAX5970_REG_STATUS2				0x33
+#define  MAX5970_IRNG_MASK				0x3
+#define  MAX5970_IRNG(reg, ch)	\
+						(((reg) >> ((ch) * 2)) & MAX5970_IRNG_MASK)
+
+#define MAX5970_REG_STATUS3				0x34
+#define  MAX5970_STATUS3_ALERT			BIT(4)
+#define  MAX5970_STATUS3_PG(ch)			BIT(ch)
+
+#define MAX5970_REG_FAULT0				0x35
+#define  UV_STATUS_WARN(ch)				BIT(ch)
+#define  UV_STATUS_CRIT(ch)				BIT(ch + 4)
+
+#define MAX5970_REG_FAULT1				0x36
+#define  OV_STATUS_WARN(ch)				BIT(ch)
+#define  OV_STATUS_CRIT(ch)				BIT(ch + 4)
+
+#define MAX5970_REG_FAULT2				0x37
+#define  OC_STATUS_WARN(ch)				BIT(ch)
+
+#define MAX5970_REG_CHXEN				0x3b
+#define  CHXEN(ch)						(3 << (ch * 2))
+
+#define MAX5970_REG_LED_FLASH			0x43
+
+#define MAX_REGISTERS					0x49
+#define ADC_MASK						0x3FF
+
+struct max597x_data {
+	struct device *dev;
+	int irq;
+	int num_switches;
+	struct regmap *regmap;
+	/* Chip specific parameters needed by regulator & iio cells */
+	u32 irng[MAX5970_NUM_SWITCHES];
+	u32 mon_rng[MAX5970_NUM_SWITCHES];
+	u32 shunt_micro_ohms[MAX5970_NUM_SWITCHES];
+};
+
+#endif
-- 
2.37.3

Re: [PATCH v11 2/2] mfd: max597x: Add support for MAX5970 and MAX5978

[Lee Jones]

On Wed, 16 Nov 2022, Naresh Solanki wrote:

> From: Patrick Rudolph <patrick.rudolph@9elements.com>
> 
> Implement a regulator driver with IRQ support for fault management.
> Written against documentation [1] and [2] and tested on real hardware.
> 
> Every channel has its own regulator supplies nammed 'vss1-supply' and
> 'vss2-supply'. The regulator supply is used to determine the output
> voltage, as the smart switch provides no output regulation.
> The driver requires the 'shunt-resistor-micro-ohms' property to be
> present in Device Tree to properly calculate current related
> values.
> 
> Datasheet links:
> 1: https://datasheets.maximintegrated.com/en/ds/MAX5970.pdf
> 2: https://datasheets.maximintegrated.com/en/ds/MAX5978.pdf
> 
> Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
> Co-developed-by: Marcello Sylvester Bauer <sylv@sylv.io>
> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> Co-developed-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> ---
>  drivers/mfd/Kconfig         |  12 +++++
>  drivers/mfd/Makefile        |   1 +
>  drivers/mfd/max597x.c       |  93 +++++++++++++++++++++++++++++++++
>  include/linux/mfd/max597x.h | 101 ++++++++++++++++++++++++++++++++++++
>  4 files changed, 207 insertions(+)
>  create mode 100644 drivers/mfd/max597x.c
>  create mode 100644 include/linux/mfd/max597x.h

Ignoring my comments won't make them go away. :)

Please tell me why you need a whole new driver, instead of adding
support to simple-mfd-i2c?

> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 8b93856de432..416fe7986b7b 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -253,6 +253,18 @@ config MFD_MADERA_SPI
>  	  Support for the Cirrus Logic Madera platform audio SoC
>  	  core functionality controlled via SPI.
>  
> +config MFD_MAX597X
> +	tristate "Maxim 597x Power Switch and Monitor"
> +	depends on I2C
> +	depends on OF
> +	select MFD_CORE
> +	select REGMAP_I2C
> +	help
> +	  This driver controls a Maxim 5970/5978 switch via I2C bus.
> +	  The MAX5970/5978 is a smart switch with no output regulation, but
> +	  fault protection and voltage and current monitoring capabilities.
> +	  Also it supports upto 4 indication LEDs.
> +
>  config MFD_CS47L15
>  	bool "Cirrus Logic CS47L15"
>  	select PINCTRL_CS47L15
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 7ed3ef4a698c..819d711fa748 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -161,6 +161,7 @@ obj-$(CONFIG_MFD_DA9063)	+= da9063.o
>  obj-$(CONFIG_MFD_DA9150)	+= da9150-core.o
>  
>  obj-$(CONFIG_MFD_MAX14577)	+= max14577.o
> +obj-$(CONFIG_MFD_MAX597X)	+= max597x.o
>  obj-$(CONFIG_MFD_MAX77620)	+= max77620.o
>  obj-$(CONFIG_MFD_MAX77650)	+= max77650.o
>  obj-$(CONFIG_MFD_MAX77686)	+= max77686.o
> diff --git a/drivers/mfd/max597x.c b/drivers/mfd/max597x.c
> new file mode 100644
> index 000000000000..45838413f24a
> --- /dev/null
> +++ b/drivers/mfd/max597x.c
> @@ -0,0 +1,93 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Maxim MAX5970/MAX5978 Power Switch & Monitor
> + *
> + * Copyright (c) 2022 9elements GmbH
> + *
> + * Author: Patrick Rudolph <patrick.rudolph@9elements.com>
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/max597x.h>
> +#include <linux/regmap.h>
> +
> +static const struct regmap_config max597x_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = MAX_REGISTERS,
> +};
> +
> +static const struct mfd_cell max597x_cells[] = {
> +	{ .name = "max597x-regulator", },
> +	{ .name = "max597x-iio", },
> +	{ .name = "max597x-led", },
> +};
> +
> +static int max597x_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
> +{
> +	struct max597x_data *ddata;
> +	enum max597x_chip_type chip = id->driver_data;
> +
> +	ddata = devm_kzalloc(&i2c->dev, sizeof(*ddata),	GFP_KERNEL);
> +	if (!ddata)
> +		return -ENOMEM;
> +
> +	/*
> +	 * Based on chip type, Initialize the number of switch. This is needed by
> +	 * regulator & iio cells.
> +	 */
> +	switch (chip) {
> +	case MAX597x_TYPE_MAX5970:
> +		ddata->num_switches = MAX5970_NUM_SWITCHES;
> +		break;
> +	case MAX597x_TYPE_MAX5978:
> +		ddata->num_switches = MAX5978_NUM_SWITCHES;
> +		break;
> +	}
> +
> +	ddata->regmap = devm_regmap_init_i2c(i2c, &max597x_regmap_config);
> +	if (IS_ERR(ddata->regmap)) {
> +		dev_err(&i2c->dev, "Failed to initialize regmap");
> +		return PTR_ERR(ddata->regmap);
> +	}
> +
> +	/* IRQ used by regulator cell */
> +	ddata->irq = i2c->irq;
> +	ddata->dev = &i2c->dev;
> +	i2c_set_clientdata(i2c, ddata);
> +
> +	return devm_mfd_add_devices(ddata->dev, PLATFORM_DEVID_AUTO,
> +				    max597x_cells, ARRAY_SIZE(max597x_cells),
> +				    NULL, 0, NULL);
> +}
> +
> +static const struct i2c_device_id max597x_table[] = {
> +	{ .name = "max5970", MAX597x_TYPE_MAX5970 },
> +	{ .name = "max5978", MAX597x_TYPE_MAX5978 },
> +	{}
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, max597x_table);
> +
> +static const struct of_device_id max597x_of_match[] = {
> +	{ .compatible = "maxim,max5970" },
> +	{ .compatible = "maxim,max5978" },
> +	{}
> +};
> +
> +MODULE_DEVICE_TABLE(of, max597x_of_match);
> +
> +static struct i2c_driver max597x_driver = {
> +	.id_table = max597x_table,
> +	.driver = {
> +		  .name = "max597x",
> +		  .of_match_table = of_match_ptr(max597x_of_match),
> +		  },
> +	.probe = max597x_probe,
> +};
> +module_i2c_driver(max597x_driver);
> +
> +MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
> +MODULE_DESCRIPTION("MAX597X Power Switch and Monitor");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/mfd/max597x.h b/include/linux/mfd/max597x.h
> new file mode 100644
> index 000000000000..706eff9c50a4
> --- /dev/null
> +++ b/include/linux/mfd/max597x.h
> @@ -0,0 +1,101 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Maxim MAX5970/MAX5978 Power Switch & Monitor
> + *
> + * Copyright (c) 2022 9elements GmbH
> + *
> + * Author: Patrick Rudolph <patrick.rudolph@9elements.com>
> + */
> +
> +#ifndef MFD_MAX597X_H
> +#define MFD_MAX597X_H
> +
> +#include <linux/device.h>
> +#include <linux/regmap.h>
> +
> +#define MAX5970_NUM_SWITCHES 2
> +#define MAX5978_NUM_SWITCHES 1
> +#define MAX597X_NUM_LEDS     4
> +
> +enum max597x_chip_type {
> +	MAX597x_TYPE_MAX5978 = 1,
> +	MAX597x_TYPE_MAX5970,
> +};
> +
> +#define MAX5970_REG_CURRENT_L(ch)		(0x01 + (ch) * 4)
> +#define MAX5970_REG_CURRENT_H(ch)		(0x00 + (ch) * 4)
> +#define MAX5970_REG_VOLTAGE_L(ch)		(0x03 + (ch) * 4)
> +#define MAX5970_REG_VOLTAGE_H(ch)		(0x02 + (ch) * 4)
> +#define MAX5970_REG_MON_RANGE			0x18
> +#define  MAX5970_MON_MASK				0x3
> +#define  MAX5970_MON(reg, ch)		(((reg) >> ((ch) * 2)) & MAX5970_MON_MASK)
> +#define  MAX5970_MON_MAX_RANGE_UV		16000000
> +
> +#define MAX5970_REG_CH_UV_WARN_H(ch)	(0x1A + (ch) * 10)
> +#define MAX5970_REG_CH_UV_WARN_L(ch)	(0x1B + (ch) * 10)
> +#define MAX5970_REG_CH_UV_CRIT_H(ch)	(0x1C + (ch) * 10)
> +#define MAX5970_REG_CH_UV_CRIT_L(ch)	(0x1D + (ch) * 10)
> +#define MAX5970_REG_CH_OV_WARN_H(ch)	(0x1E + (ch) * 10)
> +#define MAX5970_REG_CH_OV_WARN_L(ch)	(0x1F + (ch) * 10)
> +#define MAX5970_REG_CH_OV_CRIT_H(ch)	(0x20 + (ch) * 10)
> +#define MAX5970_REG_CH_OV_CRIT_L(ch)	(0x21 + (ch) * 10)
> +
> +#define  MAX5970_VAL2REG_H(x)			(((x) >> 2) & 0xFF)
> +#define  MAX5970_VAL2REG_L(x)			((x) & 0x3)
> +
> +#define MAX5970_REG_DAC_FAST(ch)		(0x2E + (ch))
> +
> +#define MAX5970_FAST2SLOW_RATIO			200
> +
> +#define MAX5970_REG_STATUS0				0x31
> +#define  MAX5970_CB_IFAULTF(ch)			(1 << (ch))
> +#define  MAX5970_CB_IFAULTS(ch)			(1 << ((ch) + 4))
> +
> +#define MAX5970_REG_STATUS1				0x32
> +#define  STATUS1_PROT_MASK				0x3
> +#define  STATUS1_PROT(reg) \
> +	(((reg) >> 6) & STATUS1_PROT_MASK)
> +#define  STATUS1_PROT_SHUTDOWN			0
> +#define  STATUS1_PROT_CLEAR_PG			1
> +#define  STATUS1_PROT_ALERT_ONLY		2
> +
> +#define MAX5970_REG_STATUS2				0x33
> +#define  MAX5970_IRNG_MASK				0x3
> +#define  MAX5970_IRNG(reg, ch)	\
> +						(((reg) >> ((ch) * 2)) & MAX5970_IRNG_MASK)
> +
> +#define MAX5970_REG_STATUS3				0x34
> +#define  MAX5970_STATUS3_ALERT			BIT(4)
> +#define  MAX5970_STATUS3_PG(ch)			BIT(ch)
> +
> +#define MAX5970_REG_FAULT0				0x35
> +#define  UV_STATUS_WARN(ch)				BIT(ch)
> +#define  UV_STATUS_CRIT(ch)				BIT(ch + 4)
> +
> +#define MAX5970_REG_FAULT1				0x36
> +#define  OV_STATUS_WARN(ch)				BIT(ch)
> +#define  OV_STATUS_CRIT(ch)				BIT(ch + 4)
> +
> +#define MAX5970_REG_FAULT2				0x37
> +#define  OC_STATUS_WARN(ch)				BIT(ch)
> +
> +#define MAX5970_REG_CHXEN				0x3b
> +#define  CHXEN(ch)						(3 << (ch * 2))
> +
> +#define MAX5970_REG_LED_FLASH			0x43
> +
> +#define MAX_REGISTERS					0x49
> +#define ADC_MASK						0x3FF
> +
> +struct max597x_data {
> +	struct device *dev;
> +	int irq;
> +	int num_switches;
> +	struct regmap *regmap;
> +	/* Chip specific parameters needed by regulator & iio cells */
> +	u32 irng[MAX5970_NUM_SWITCHES];
> +	u32 mon_rng[MAX5970_NUM_SWITCHES];
> +	u32 shunt_micro_ohms[MAX5970_NUM_SWITCHES];
> +};
> +
> +#endif

-- 
Lee Jones [李琼斯]

Re: [PATCH v11 1/2] dt-bindings: mfd: Add MAX5970 and MAX5978

[Krzysztof Kozlowski]

On 16/11/2022 21:58, Naresh Solanki wrote:
> From: Marcello Sylvester Bauer <sylv@sylv.io>
> 
> The MAX597x is a hot swap controller with configurable fault protection.
> It also has 10bit ADC for current & voltage measurements.
> 
> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> Co-developed-by: Patrick Rudolph <patrick.rudolph@9elements.com>
> Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
> Co-developed-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> ---


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

Re: [PATCH v11 2/2] mfd: max597x: Add support for MAX5970 and MAX5978

[Naresh Solanki]

On 17-11-2022 03:45 pm, Lee Jones wrote:
> On Wed, 16 Nov 2022, Naresh Solanki wrote:
> 
>> From: Patrick Rudolph <patrick.rudolph@9elements.com>
>>
>> Implement a regulator driver with IRQ support for fault management.
>> Written against documentation [1] and [2] and tested on real hardware.
>>
>> Every channel has its own regulator supplies nammed 'vss1-supply' and
>> 'vss2-supply'. The regulator supply is used to determine the output
>> voltage, as the smart switch provides no output regulation.
>> The driver requires the 'shunt-resistor-micro-ohms' property to be
>> present in Device Tree to properly calculate current related
>> values.
>>
>> Datasheet links:
>> 1: https://datasheets.maximintegrated.com/en/ds/MAX5970.pdf
>> 2: https://datasheets.maximintegrated.com/en/ds/MAX5978.pdf
>>
>> Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
>> Co-developed-by: Marcello Sylvester Bauer <sylv@sylv.io>
>> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
>> Co-developed-by: Naresh Solanki <Naresh.Solanki@9elements.com>
>> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
>> ---
>>   drivers/mfd/Kconfig         |  12 +++++
>>   drivers/mfd/Makefile        |   1 +
>>   drivers/mfd/max597x.c       |  93 +++++++++++++++++++++++++++++++++
>>   include/linux/mfd/max597x.h | 101 ++++++++++++++++++++++++++++++++++++
>>   4 files changed, 207 insertions(+)
>>   create mode 100644 drivers/mfd/max597x.c
>>   create mode 100644 include/linux/mfd/max597x.h
> 
> Ignoring my comments won't make them go away. :)
> 
> Please tell me why you need a whole new driver, instead of adding
> support to simple-mfd-i2c?
> 
I felt current implementation to be simpler, clearer & straight forward.

>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>> index 8b93856de432..416fe7986b7b 100644
>> --- a/drivers/mfd/Kconfig
>> +++ b/drivers/mfd/Kconfig
>> @@ -253,6 +253,18 @@ config MFD_MADERA_SPI
>>   	  Support for the Cirrus Logic Madera platform audio SoC
>>   	  core functionality controlled via SPI.
>>   
>> +config MFD_MAX597X
>> +	tristate "Maxim 597x Power Switch and Monitor"
>> +	depends on I2C
>> +	depends on OF
>> +	select MFD_CORE
>> +	select REGMAP_I2C
>> +	help
>> +	  This driver controls a Maxim 5970/5978 switch via I2C bus.
>> +	  The MAX5970/5978 is a smart switch with no output regulation, but
>> +	  fault protection and voltage and current monitoring capabilities.
>> +	  Also it supports upto 4 indication LEDs.
>> +
>>   config MFD_CS47L15
>>   	bool "Cirrus Logic CS47L15"
>>   	select PINCTRL_CS47L15
>> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
>> index 7ed3ef4a698c..819d711fa748 100644
>> --- a/drivers/mfd/Makefile
>> +++ b/drivers/mfd/Makefile
>> @@ -161,6 +161,7 @@ obj-$(CONFIG_MFD_DA9063)	+= da9063.o
>>   obj-$(CONFIG_MFD_DA9150)	+= da9150-core.o
>>   
>>   obj-$(CONFIG_MFD_MAX14577)	+= max14577.o
>> +obj-$(CONFIG_MFD_MAX597X)	+= max597x.o
>>   obj-$(CONFIG_MFD_MAX77620)	+= max77620.o
>>   obj-$(CONFIG_MFD_MAX77650)	+= max77650.o
>>   obj-$(CONFIG_MFD_MAX77686)	+= max77686.o
>> diff --git a/drivers/mfd/max597x.c b/drivers/mfd/max597x.c
>> new file mode 100644
>> index 000000000000..45838413f24a
>> --- /dev/null
>> +++ b/drivers/mfd/max597x.c
>> @@ -0,0 +1,93 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Maxim MAX5970/MAX5978 Power Switch & Monitor
>> + *
>> + * Copyright (c) 2022 9elements GmbH
>> + *
>> + * Author: Patrick Rudolph <patrick.rudolph@9elements.com>
>> + */
>> +
>> +#include <linux/i2c.h>
>> +#include <linux/mfd/core.h>
>> +#include <linux/mfd/max597x.h>
>> +#include <linux/regmap.h>
>> +
>> +static const struct regmap_config max597x_regmap_config = {
>> +	.reg_bits = 8,
>> +	.val_bits = 8,
>> +	.max_register = MAX_REGISTERS,
>> +};
>> +
>> +static const struct mfd_cell max597x_cells[] = {
>> +	{ .name = "max597x-regulator", },
>> +	{ .name = "max597x-iio", },
>> +	{ .name = "max597x-led", },
>> +};
>> +
>> +static int max597x_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
>> +{
>> +	struct max597x_data *ddata;
>> +	enum max597x_chip_type chip = id->driver_data;
>> +
>> +	ddata = devm_kzalloc(&i2c->dev, sizeof(*ddata),	GFP_KERNEL);
>> +	if (!ddata)
>> +		return -ENOMEM;
>> +
>> +	/*
>> +	 * Based on chip type, Initialize the number of switch. This is needed by
>> +	 * regulator & iio cells.
>> +	 */
>> +	switch (chip) {
>> +	case MAX597x_TYPE_MAX5970:
>> +		ddata->num_switches = MAX5970_NUM_SWITCHES;
>> +		break;
>> +	case MAX597x_TYPE_MAX5978:
>> +		ddata->num_switches = MAX5978_NUM_SWITCHES;
>> +		break;
>> +	}
>> +
>> +	ddata->regmap = devm_regmap_init_i2c(i2c, &max597x_regmap_config);
>> +	if (IS_ERR(ddata->regmap)) {
>> +		dev_err(&i2c->dev, "Failed to initialize regmap");
>> +		return PTR_ERR(ddata->regmap);
>> +	}
>> +
>> +	/* IRQ used by regulator cell */
>> +	ddata->irq = i2c->irq;
>> +	ddata->dev = &i2c->dev;
>> +	i2c_set_clientdata(i2c, ddata);
>> +
>> +	return devm_mfd_add_devices(ddata->dev, PLATFORM_DEVID_AUTO,
>> +				    max597x_cells, ARRAY_SIZE(max597x_cells),
>> +				    NULL, 0, NULL);
>> +}
>> +
>> +static const struct i2c_device_id max597x_table[] = {
>> +	{ .name = "max5970", MAX597x_TYPE_MAX5970 },
>> +	{ .name = "max5978", MAX597x_TYPE_MAX5978 },
>> +	{}
>> +};
>> +
>> +MODULE_DEVICE_TABLE(i2c, max597x_table);
>> +
>> +static const struct of_device_id max597x_of_match[] = {
>> +	{ .compatible = "maxim,max5970" },
>> +	{ .compatible = "maxim,max5978" },
>> +	{}
>> +};
>> +
>> +MODULE_DEVICE_TABLE(of, max597x_of_match);
>> +
>> +static struct i2c_driver max597x_driver = {
>> +	.id_table = max597x_table,
>> +	.driver = {
>> +		  .name = "max597x",
>> +		  .of_match_table = of_match_ptr(max597x_of_match),
>> +		  },
>> +	.probe = max597x_probe,
>> +};
>> +module_i2c_driver(max597x_driver);
>> +
>> +MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
>> +MODULE_DESCRIPTION("MAX597X Power Switch and Monitor");
>> +MODULE_LICENSE("GPL v2");
>> diff --git a/include/linux/mfd/max597x.h b/include/linux/mfd/max597x.h
>> new file mode 100644
>> index 000000000000..706eff9c50a4
>> --- /dev/null
>> +++ b/include/linux/mfd/max597x.h
>> @@ -0,0 +1,101 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * Maxim MAX5970/MAX5978 Power Switch & Monitor
>> + *
>> + * Copyright (c) 2022 9elements GmbH
>> + *
>> + * Author: Patrick Rudolph <patrick.rudolph@9elements.com>
>> + */
>> +
>> +#ifndef MFD_MAX597X_H
>> +#define MFD_MAX597X_H
>> +
>> +#include <linux/device.h>
>> +#include <linux/regmap.h>
>> +
>> +#define MAX5970_NUM_SWITCHES 2
>> +#define MAX5978_NUM_SWITCHES 1
>> +#define MAX597X_NUM_LEDS     4
>> +
>> +enum max597x_chip_type {
>> +	MAX597x_TYPE_MAX5978 = 1,
>> +	MAX597x_TYPE_MAX5970,
>> +};
>> +
>> +#define MAX5970_REG_CURRENT_L(ch)		(0x01 + (ch) * 4)
>> +#define MAX5970_REG_CURRENT_H(ch)		(0x00 + (ch) * 4)
>> +#define MAX5970_REG_VOLTAGE_L(ch)		(0x03 + (ch) * 4)
>> +#define MAX5970_REG_VOLTAGE_H(ch)		(0x02 + (ch) * 4)
>> +#define MAX5970_REG_MON_RANGE			0x18
>> +#define  MAX5970_MON_MASK				0x3
>> +#define  MAX5970_MON(reg, ch)		(((reg) >> ((ch) * 2)) & MAX5970_MON_MASK)
>> +#define  MAX5970_MON_MAX_RANGE_UV		16000000
>> +
>> +#define MAX5970_REG_CH_UV_WARN_H(ch)	(0x1A + (ch) * 10)
>> +#define MAX5970_REG_CH_UV_WARN_L(ch)	(0x1B + (ch) * 10)
>> +#define MAX5970_REG_CH_UV_CRIT_H(ch)	(0x1C + (ch) * 10)
>> +#define MAX5970_REG_CH_UV_CRIT_L(ch)	(0x1D + (ch) * 10)
>> +#define MAX5970_REG_CH_OV_WARN_H(ch)	(0x1E + (ch) * 10)
>> +#define MAX5970_REG_CH_OV_WARN_L(ch)	(0x1F + (ch) * 10)
>> +#define MAX5970_REG_CH_OV_CRIT_H(ch)	(0x20 + (ch) * 10)
>> +#define MAX5970_REG_CH_OV_CRIT_L(ch)	(0x21 + (ch) * 10)
>> +
>> +#define  MAX5970_VAL2REG_H(x)			(((x) >> 2) & 0xFF)
>> +#define  MAX5970_VAL2REG_L(x)			((x) & 0x3)
>> +
>> +#define MAX5970_REG_DAC_FAST(ch)		(0x2E + (ch))
>> +
>> +#define MAX5970_FAST2SLOW_RATIO			200
>> +
>> +#define MAX5970_REG_STATUS0				0x31
>> +#define  MAX5970_CB_IFAULTF(ch)			(1 << (ch))
>> +#define  MAX5970_CB_IFAULTS(ch)			(1 << ((ch) + 4))
>> +
>> +#define MAX5970_REG_STATUS1				0x32
>> +#define  STATUS1_PROT_MASK				0x3
>> +#define  STATUS1_PROT(reg) \
>> +	(((reg) >> 6) & STATUS1_PROT_MASK)
>> +#define  STATUS1_PROT_SHUTDOWN			0
>> +#define  STATUS1_PROT_CLEAR_PG			1
>> +#define  STATUS1_PROT_ALERT_ONLY		2
>> +
>> +#define MAX5970_REG_STATUS2				0x33
>> +#define  MAX5970_IRNG_MASK				0x3
>> +#define  MAX5970_IRNG(reg, ch)	\
>> +						(((reg) >> ((ch) * 2)) & MAX5970_IRNG_MASK)
>> +
>> +#define MAX5970_REG_STATUS3				0x34
>> +#define  MAX5970_STATUS3_ALERT			BIT(4)
>> +#define  MAX5970_STATUS3_PG(ch)			BIT(ch)
>> +
>> +#define MAX5970_REG_FAULT0				0x35
>> +#define  UV_STATUS_WARN(ch)				BIT(ch)
>> +#define  UV_STATUS_CRIT(ch)				BIT(ch + 4)
>> +
>> +#define MAX5970_REG_FAULT1				0x36
>> +#define  OV_STATUS_WARN(ch)				BIT(ch)
>> +#define  OV_STATUS_CRIT(ch)				BIT(ch + 4)
>> +
>> +#define MAX5970_REG_FAULT2				0x37
>> +#define  OC_STATUS_WARN(ch)				BIT(ch)
>> +
>> +#define MAX5970_REG_CHXEN				0x3b
>> +#define  CHXEN(ch)						(3 << (ch * 2))
>> +
>> +#define MAX5970_REG_LED_FLASH			0x43
>> +
>> +#define MAX_REGISTERS					0x49
>> +#define ADC_MASK						0x3FF
>> +
>> +struct max597x_data {
>> +	struct device *dev;
>> +	int irq;
>> +	int num_switches;
>> +	struct regmap *regmap;
>> +	/* Chip specific parameters needed by regulator & iio cells */
>> +	u32 irng[MAX5970_NUM_SWITCHES];
>> +	u32 mon_rng[MAX5970_NUM_SWITCHES];
>> +	u32 shunt_micro_ohms[MAX5970_NUM_SWITCHES];
>> +};
>> +
>> +#endif
> 

Re: [PATCH v11 2/2] mfd: max597x: Add support for MAX5970 and MAX5978

[Lee Jones]

On Fri, 18 Nov 2022, Naresh Solanki wrote:

> 
> 
> On 17-11-2022 03:45 pm, Lee Jones wrote:
> > On Wed, 16 Nov 2022, Naresh Solanki wrote:
> > 
> > > From: Patrick Rudolph <patrick.rudolph@9elements.com>
> > > 
> > > Implement a regulator driver with IRQ support for fault management.
> > > Written against documentation [1] and [2] and tested on real hardware.
> > > 
> > > Every channel has its own regulator supplies nammed 'vss1-supply' and
> > > 'vss2-supply'. The regulator supply is used to determine the output
> > > voltage, as the smart switch provides no output regulation.
> > > The driver requires the 'shunt-resistor-micro-ohms' property to be
> > > present in Device Tree to properly calculate current related
> > > values.
> > > 
> > > Datasheet links:
> > > 1: https://datasheets.maximintegrated.com/en/ds/MAX5970.pdf
> > > 2: https://datasheets.maximintegrated.com/en/ds/MAX5978.pdf
> > > 
> > > Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
> > > Co-developed-by: Marcello Sylvester Bauer <sylv@sylv.io>
> > > Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> > > Co-developed-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> > > Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> > > ---
> > >   drivers/mfd/Kconfig         |  12 +++++
> > >   drivers/mfd/Makefile        |   1 +
> > >   drivers/mfd/max597x.c       |  93 +++++++++++++++++++++++++++++++++
> > >   include/linux/mfd/max597x.h | 101 ++++++++++++++++++++++++++++++++++++
> > >   4 files changed, 207 insertions(+)
> > >   create mode 100644 drivers/mfd/max597x.c
> > >   create mode 100644 include/linux/mfd/max597x.h
> > 
> > Ignoring my comments won't make them go away. :)
> > 
> > Please tell me why you need a whole new driver, instead of adding
> > support to simple-mfd-i2c?
> > 
> I felt current implementation to be simpler, clearer & straight forward.

If you can make it work with simple-mfd-i2c, please do so.

No need to submit an entirely new driver for these simple use-cases.

-- 
Lee Jones [李琼斯]

Re: [PATCH v11 2/2] mfd: max597x: Add support for MAX5970 and MAX5978

[Naresh Solanki]

Hi Lee

On 08-12-2022 05:53 pm, Lee Jones wrote:
> On Fri, 18 Nov 2022, Naresh Solanki wrote:
> 
>>
>>
>> On 17-11-2022 03:45 pm, Lee Jones wrote:
>>> On Wed, 16 Nov 2022, Naresh Solanki wrote:
>>>
>>>> From: Patrick Rudolph <patrick.rudolph@9elements.com>
>>>>
>>>> Implement a regulator driver with IRQ support for fault management.
>>>> Written against documentation [1] and [2] and tested on real hardware.
>>>>
>>>> Every channel has its own regulator supplies nammed 'vss1-supply' and
>>>> 'vss2-supply'. The regulator supply is used to determine the output
>>>> voltage, as the smart switch provides no output regulation.
>>>> The driver requires the 'shunt-resistor-micro-ohms' property to be
>>>> present in Device Tree to properly calculate current related
>>>> values.
>>>>
>>>> Datasheet links:
>>>> 1: https://datasheets.maximintegrated.com/en/ds/MAX5970.pdf
>>>> 2: https://datasheets.maximintegrated.com/en/ds/MAX5978.pdf
>>>>
>>>> Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
>>>> Co-developed-by: Marcello Sylvester Bauer <sylv@sylv.io>
>>>> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
>>>> Co-developed-by: Naresh Solanki <Naresh.Solanki@9elements.com>
>>>> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
>>>> ---
>>>>    drivers/mfd/Kconfig         |  12 +++++
>>>>    drivers/mfd/Makefile        |   1 +
>>>>    drivers/mfd/max597x.c       |  93 +++++++++++++++++++++++++++++++++
>>>>    include/linux/mfd/max597x.h | 101 ++++++++++++++++++++++++++++++++++++
>>>>    4 files changed, 207 insertions(+)
>>>>    create mode 100644 drivers/mfd/max597x.c
>>>>    create mode 100644 include/linux/mfd/max597x.h
>>>
>>> Ignoring my comments won't make them go away. :)
>>>
>>> Please tell me why you need a whole new driver, instead of adding
>>> support to simple-mfd-i2c?
>>>
>> I felt current implementation to be simpler, clearer & straight forward.
> 
> If you can make it work with simple-mfd-i2c, please do so.
simple-mfd-i2c doesn't has mechanism to pass device type(max5978 vs 
max5970).
> 
> No need to submit an entirely new driver for these simple use-cases.
> 
Regards,
Naresh

Re: [PATCH v11 2/2] mfd: max597x: Add support for MAX5970 and MAX5978

[Lee Jones]

On Wed, 14 Dec 2022, Naresh Solanki wrote:

> Hi Lee
> 
> On 08-12-2022 05:53 pm, Lee Jones wrote:
> > On Fri, 18 Nov 2022, Naresh Solanki wrote:
> > 
> > > 
> > > 
> > > On 17-11-2022 03:45 pm, Lee Jones wrote:
> > > > On Wed, 16 Nov 2022, Naresh Solanki wrote:
> > > > 
> > > > > From: Patrick Rudolph <patrick.rudolph@9elements.com>
> > > > > 
> > > > > Implement a regulator driver with IRQ support for fault management.
> > > > > Written against documentation [1] and [2] and tested on real hardware.
> > > > > 
> > > > > Every channel has its own regulator supplies nammed 'vss1-supply' and
> > > > > 'vss2-supply'. The regulator supply is used to determine the output
> > > > > voltage, as the smart switch provides no output regulation.
> > > > > The driver requires the 'shunt-resistor-micro-ohms' property to be
> > > > > present in Device Tree to properly calculate current related
> > > > > values.
> > > > > 
> > > > > Datasheet links:
> > > > > 1: https://datasheets.maximintegrated.com/en/ds/MAX5970.pdf
> > > > > 2: https://datasheets.maximintegrated.com/en/ds/MAX5978.pdf
> > > > > 
> > > > > Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
> > > > > Co-developed-by: Marcello Sylvester Bauer <sylv@sylv.io>
> > > > > Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> > > > > Co-developed-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> > > > > Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> > > > > ---
> > > > >    drivers/mfd/Kconfig         |  12 +++++
> > > > >    drivers/mfd/Makefile        |   1 +
> > > > >    drivers/mfd/max597x.c       |  93 +++++++++++++++++++++++++++++++++
> > > > >    include/linux/mfd/max597x.h | 101 ++++++++++++++++++++++++++++++++++++
> > > > >    4 files changed, 207 insertions(+)
> > > > >    create mode 100644 drivers/mfd/max597x.c
> > > > >    create mode 100644 include/linux/mfd/max597x.h
> > > > 
> > > > Ignoring my comments won't make them go away. :)
> > > > 
> > > > Please tell me why you need a whole new driver, instead of adding
> > > > support to simple-mfd-i2c?
> > > > 
> > > I felt current implementation to be simpler, clearer & straight forward.
> > 
> > If you can make it work with simple-mfd-i2c, please do so.
> simple-mfd-i2c doesn't has mechanism to pass device type(max5978 vs
> max5970).

`git grep silergy,sy7636a -- drivers/mfd`

> > No need to submit an entirely new driver for these simple use-cases.

-- 
Lee Jones [李琼斯]

Re: [PATCH v11 2/2] mfd: max597x: Add support for MAX5970 and MAX5978

[Naresh Solanki]

Hi Lee,

On 14-12-2022 03:17 pm, Lee Jones wrote:
> On Wed, 14 Dec 2022, Naresh Solanki wrote:
> 
>> Hi Lee
>>
>> On 08-12-2022 05:53 pm, Lee Jones wrote:
>>> On Fri, 18 Nov 2022, Naresh Solanki wrote:
>>>
>>>>
>>>>
>>>> On 17-11-2022 03:45 pm, Lee Jones wrote:
>>>>> On Wed, 16 Nov 2022, Naresh Solanki wrote:
>>>>>
>>>>>> From: Patrick Rudolph <patrick.rudolph@9elements.com>
>>>>>>
>>>>>> Implement a regulator driver with IRQ support for fault management.
>>>>>> Written against documentation [1] and [2] and tested on real hardware.
>>>>>>
>>>>>> Every channel has its own regulator supplies nammed 'vss1-supply' and
>>>>>> 'vss2-supply'. The regulator supply is used to determine the output
>>>>>> voltage, as the smart switch provides no output regulation.
>>>>>> The driver requires the 'shunt-resistor-micro-ohms' property to be
>>>>>> present in Device Tree to properly calculate current related
>>>>>> values.
>>>>>>
>>>>>> Datasheet links:
>>>>>> 1: https://datasheets.maximintegrated.com/en/ds/MAX5970.pdf
>>>>>> 2: https://datasheets.maximintegrated.com/en/ds/MAX5978.pdf
>>>>>>
>>>>>> Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
>>>>>> Co-developed-by: Marcello Sylvester Bauer <sylv@sylv.io>
>>>>>> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
>>>>>> Co-developed-by: Naresh Solanki <Naresh.Solanki@9elements.com>
>>>>>> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
>>>>>> ---
>>>>>>     drivers/mfd/Kconfig         |  12 +++++
>>>>>>     drivers/mfd/Makefile        |   1 +
>>>>>>     drivers/mfd/max597x.c       |  93 +++++++++++++++++++++++++++++++++
>>>>>>     include/linux/mfd/max597x.h | 101 ++++++++++++++++++++++++++++++++++++
>>>>>>     4 files changed, 207 insertions(+)
>>>>>>     create mode 100644 drivers/mfd/max597x.c
>>>>>>     create mode 100644 include/linux/mfd/max597x.h
>>>>>
>>>>> Ignoring my comments won't make them go away. :)
>>>>>
>>>>> Please tell me why you need a whole new driver, instead of adding
>>>>> support to simple-mfd-i2c?
>>>>>
>>>> I felt current implementation to be simpler, clearer & straight forward.
>>>
>>> If you can make it work with simple-mfd-i2c, please do so.
>> simple-mfd-i2c doesn't has mechanism to pass device type(max5978 vs
>> max5970).
> 
> `git grep silergy,sy7636a -- drivers/mfd`
I did check the driver but there is no mechanism to distinguish between 
chip variant i.e., 597x-regulator driver should be able to distinguish 
between max5978 vs max5970 chip type.
> 
>>> No need to submit an entirely new driver for these simple use-cases.
> 

Re: [PATCH v11 2/2] mfd: max597x: Add support for MAX5970 and MAX5978

[Lee Jones]

On Wed, 14 Dec 2022, Naresh Solanki wrote:

> Hi Lee,
> 
> On 14-12-2022 03:17 pm, Lee Jones wrote:
> > On Wed, 14 Dec 2022, Naresh Solanki wrote:
> > 
> > > Hi Lee
> > > 
> > > On 08-12-2022 05:53 pm, Lee Jones wrote:
> > > > On Fri, 18 Nov 2022, Naresh Solanki wrote:
> > > > 
> > > > > 
> > > > > 
> > > > > On 17-11-2022 03:45 pm, Lee Jones wrote:
> > > > > > On Wed, 16 Nov 2022, Naresh Solanki wrote:
> > > > > > 
> > > > > > > From: Patrick Rudolph <patrick.rudolph@9elements.com>
> > > > > > > 
> > > > > > > Implement a regulator driver with IRQ support for fault management.
> > > > > > > Written against documentation [1] and [2] and tested on real hardware.
> > > > > > > 
> > > > > > > Every channel has its own regulator supplies nammed 'vss1-supply' and
> > > > > > > 'vss2-supply'. The regulator supply is used to determine the output
> > > > > > > voltage, as the smart switch provides no output regulation.
> > > > > > > The driver requires the 'shunt-resistor-micro-ohms' property to be
> > > > > > > present in Device Tree to properly calculate current related
> > > > > > > values.
> > > > > > > 
> > > > > > > Datasheet links:
> > > > > > > 1: https://datasheets.maximintegrated.com/en/ds/MAX5970.pdf
> > > > > > > 2: https://datasheets.maximintegrated.com/en/ds/MAX5978.pdf
> > > > > > > 
> > > > > > > Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
> > > > > > > Co-developed-by: Marcello Sylvester Bauer <sylv@sylv.io>
> > > > > > > Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> > > > > > > Co-developed-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> > > > > > > Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> > > > > > > ---
> > > > > > >     drivers/mfd/Kconfig         |  12 +++++
> > > > > > >     drivers/mfd/Makefile        |   1 +
> > > > > > >     drivers/mfd/max597x.c       |  93 +++++++++++++++++++++++++++++++++
> > > > > > >     include/linux/mfd/max597x.h | 101 ++++++++++++++++++++++++++++++++++++
> > > > > > >     4 files changed, 207 insertions(+)
> > > > > > >     create mode 100644 drivers/mfd/max597x.c
> > > > > > >     create mode 100644 include/linux/mfd/max597x.h
> > > > > > 
> > > > > > Ignoring my comments won't make them go away. :)
> > > > > > 
> > > > > > Please tell me why you need a whole new driver, instead of adding
> > > > > > support to simple-mfd-i2c?
> > > > > > 
> > > > > I felt current implementation to be simpler, clearer & straight forward.
> > > > 
> > > > If you can make it work with simple-mfd-i2c, please do so.
> > > simple-mfd-i2c doesn't has mechanism to pass device type(max5978 vs
> > > max5970).
> > 
> > `git grep silergy,sy7636a -- drivers/mfd`
> I did check the driver but there is no mechanism to distinguish between chip
> variant i.e., 597x-regulator driver should be able to distinguish between
> max5978 vs max5970 chip type.

How is it doing that presently?

Why can't the Regulator driver read the DT or match on the parent's
compatible for itself?

Providing a 100 line driver just to figure out a single value that is
only going to be used in a single driver is a no-go.  Please find a
better way to solve this.

-- 
Lee Jones [李琼斯]

Re: [PATCH v11 2/2] mfd: max597x: Add support for MAX5970 and MAX5978

[Naresh Solanki]

Hi Lee,

On 23-12-2022 06:06 pm, Lee Jones wrote:
> On Wed, 14 Dec 2022, Naresh Solanki wrote:
> 
>> Hi Lee,
>>
>> On 14-12-2022 03:17 pm, Lee Jones wrote:
>>> On Wed, 14 Dec 2022, Naresh Solanki wrote:
>>>
>>>> Hi Lee
>>>>
>>>> On 08-12-2022 05:53 pm, Lee Jones wrote:
>>>>> On Fri, 18 Nov 2022, Naresh Solanki wrote:
>>>>>
>>>>>>
>>>>>>
>>>>>> On 17-11-2022 03:45 pm, Lee Jones wrote:
>>>>>>> On Wed, 16 Nov 2022, Naresh Solanki wrote:
>>>>>>>
>>>>>>>> From: Patrick Rudolph <patrick.rudolph@9elements.com>
>>>>>>>>
>>>>>>>> Implement a regulator driver with IRQ support for fault management.
>>>>>>>> Written against documentation [1] and [2] and tested on real hardware.
>>>>>>>>
>>>>>>>> Every channel has its own regulator supplies nammed 'vss1-supply' and
>>>>>>>> 'vss2-supply'. The regulator supply is used to determine the output
>>>>>>>> voltage, as the smart switch provides no output regulation.
>>>>>>>> The driver requires the 'shunt-resistor-micro-ohms' property to be
>>>>>>>> present in Device Tree to properly calculate current related
>>>>>>>> values.
>>>>>>>>
>>>>>>>> Datasheet links:
>>>>>>>> 1: https://datasheets.maximintegrated.com/en/ds/MAX5970.pdf
>>>>>>>> 2: https://datasheets.maximintegrated.com/en/ds/MAX5978.pdf
>>>>>>>>
>>>>>>>> Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
>>>>>>>> Co-developed-by: Marcello Sylvester Bauer <sylv@sylv.io>
>>>>>>>> Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
>>>>>>>> Co-developed-by: Naresh Solanki <Naresh.Solanki@9elements.com>
>>>>>>>> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
>>>>>>>> ---
>>>>>>>>      drivers/mfd/Kconfig         |  12 +++++
>>>>>>>>      drivers/mfd/Makefile        |   1 +
>>>>>>>>      drivers/mfd/max597x.c       |  93 +++++++++++++++++++++++++++++++++
>>>>>>>>      include/linux/mfd/max597x.h | 101 ++++++++++++++++++++++++++++++++++++
>>>>>>>>      4 files changed, 207 insertions(+)
>>>>>>>>      create mode 100644 drivers/mfd/max597x.c
>>>>>>>>      create mode 100644 include/linux/mfd/max597x.h
>>>>>>>
>>>>>>> Ignoring my comments won't make them go away. :)
>>>>>>>
>>>>>>> Please tell me why you need a whole new driver, instead of adding
>>>>>>> support to simple-mfd-i2c?
>>>>>>>
>>>>>> I felt current implementation to be simpler, clearer & straight forward.
>>>>>
>>>>> If you can make it work with simple-mfd-i2c, please do so.
>>>> simple-mfd-i2c doesn't has mechanism to pass device type(max5978 vs
>>>> max5970).
>>>
>>> `git grep silergy,sy7636a -- drivers/mfd`
>> I did check the driver but there is no mechanism to distinguish between chip
>> variant i.e., 597x-regulator driver should be able to distinguish between
>> max5978 vs max5970 chip type.
> 
> How is it doing that presently?
Using i2c_device_id. driver_data hold chip variant info based on 
compatible match.
> 
> Why can't the Regulator driver read the DT or match on the parent's
> compatible for itself?
There are three drivers i.e., max597x regulator, led & iio driver.
I'm not sure if checking compatible in each driver is ok.
Recommendation ?
> 
> Providing a 100 line driver just to figure out a single value that is
> only going to be used in a single driver is a no-go.  Please find a
> better way to solve this.Yes but simple-mfd-i2c doesn't help in distinguishing chip variant & in 
situation like absence of device id register, mfd cell driver cant 
determine chip type to initialise accordingly.
Can you please recommend me an approach that can also handle this kind 
of scenario.
> 

Regards,
Naresh

Re: [PATCH v11 2/2] mfd: max597x: Add support for MAX5970 and MAX5978

[Lee Jones]

On Tue, 03 Jan 2023, Naresh Solanki wrote:

> Hi Lee,
> 
> On 23-12-2022 06:06 pm, Lee Jones wrote:
> > On Wed, 14 Dec 2022, Naresh Solanki wrote:
> > 
> > > Hi Lee,
> > > 
> > > On 14-12-2022 03:17 pm, Lee Jones wrote:
> > > > On Wed, 14 Dec 2022, Naresh Solanki wrote:
> > > > 
> > > > > Hi Lee
> > > > > 
> > > > > On 08-12-2022 05:53 pm, Lee Jones wrote:
> > > > > > On Fri, 18 Nov 2022, Naresh Solanki wrote:
> > > > > > 
> > > > > > > 
> > > > > > > 
> > > > > > > On 17-11-2022 03:45 pm, Lee Jones wrote:
> > > > > > > > On Wed, 16 Nov 2022, Naresh Solanki wrote:
> > > > > > > > 
> > > > > > > > > From: Patrick Rudolph <patrick.rudolph@9elements.com>
> > > > > > > > > 
> > > > > > > > > Implement a regulator driver with IRQ support for fault management.
> > > > > > > > > Written against documentation [1] and [2] and tested on real hardware.
> > > > > > > > > 
> > > > > > > > > Every channel has its own regulator supplies nammed 'vss1-supply' and
> > > > > > > > > 'vss2-supply'. The regulator supply is used to determine the output
> > > > > > > > > voltage, as the smart switch provides no output regulation.
> > > > > > > > > The driver requires the 'shunt-resistor-micro-ohms' property to be
> > > > > > > > > present in Device Tree to properly calculate current related
> > > > > > > > > values.
> > > > > > > > > 
> > > > > > > > > Datasheet links:
> > > > > > > > > 1: https://datasheets.maximintegrated.com/en/ds/MAX5970.pdf
> > > > > > > > > 2: https://datasheets.maximintegrated.com/en/ds/MAX5978.pdf
> > > > > > > > > 
> > > > > > > > > Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
> > > > > > > > > Co-developed-by: Marcello Sylvester Bauer <sylv@sylv.io>
> > > > > > > > > Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
> > > > > > > > > Co-developed-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> > > > > > > > > Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
> > > > > > > > > ---
> > > > > > > > >      drivers/mfd/Kconfig         |  12 +++++
> > > > > > > > >      drivers/mfd/Makefile        |   1 +
> > > > > > > > >      drivers/mfd/max597x.c       |  93 +++++++++++++++++++++++++++++++++
> > > > > > > > >      include/linux/mfd/max597x.h | 101 ++++++++++++++++++++++++++++++++++++
> > > > > > > > >      4 files changed, 207 insertions(+)
> > > > > > > > >      create mode 100644 drivers/mfd/max597x.c
> > > > > > > > >      create mode 100644 include/linux/mfd/max597x.h
> > > > > > > > 
> > > > > > > > Ignoring my comments won't make them go away. :)
> > > > > > > > 
> > > > > > > > Please tell me why you need a whole new driver, instead of adding
> > > > > > > > support to simple-mfd-i2c?
> > > > > > > > 
> > > > > > > I felt current implementation to be simpler, clearer & straight forward.
> > > > > > 
> > > > > > If you can make it work with simple-mfd-i2c, please do so.
> > > > > simple-mfd-i2c doesn't has mechanism to pass device type(max5978 vs
> > > > > max5970).
> > > > 
> > > > `git grep silergy,sy7636a -- drivers/mfd`
> > > I did check the driver but there is no mechanism to distinguish between chip
> > > variant i.e., 597x-regulator driver should be able to distinguish between
> > > max5978 vs max5970 chip type.
> > 
> > How is it doing that presently?
> Using i2c_device_id. driver_data hold chip variant info based on compatible
> match.
> > 
> > Why can't the Regulator driver read the DT or match on the parent's
> > compatible for itself?
> There are three drivers i.e., max597x regulator, led & iio driver.
> I'm not sure if checking compatible in each driver is ok.
> Recommendation ?

Sure it is.  The leaf devices can know that they are children and can
read their parent's device tree node without issue.

> > Providing a 100 line driver just to figure out a single value that is
> > only going to be used in a single driver is a no-go.  Please find a
> > better way to solve this.Yes but simple-mfd-i2c doesn't help in
> > distinguishing chip variant & in
> situation like absence of device id register, mfd cell driver cant determine
> chip type to initialise accordingly.
> Can you please recommend me an approach that can also handle this kind of
> scenario.

Place the hardware IDs in DT.

-- 
Lee Jones [李琼斯]