[v4] leds: max597x: Add support for max597x
Commit Message
From: Patrick Rudolph <patrick.rudolph@9elements.com>
max597x is hot swap controller with indicator LED support.
This driver uses DT property to configure led during boot time &
also provide the LED control in sysfs.
DTS example:
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";
};
};
};
};
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
...
Changes in V4:
- Remove unwanted preinitialise
- Remove unneeded line breaks
- Fix variable name to avoid confusion
- Update module description to mention LED driver.
Changes in V3:
- Remove of_node_put as its handled by for loop
- Print error if an LED fails to register.
- Update driver name in Kconfig description
- Remove unneeded variable assignment
- Use devm_led_classdev_register to reget led
Changes in V2:
- Fix regmap update
- Remove devm_kfree
- Remove default-state
- Add example dts in commit message
- Fix whitespace in Kconfig
- Fix comment
---
drivers/leds/Kconfig | 11 ++++
drivers/leds/Makefile | 1 +
drivers/leds/leds-max597x.c | 112 ++++++++++++++++++++++++++++++++++++
3 files changed, 124 insertions(+)
create mode 100644 drivers/leds/leds-max597x.c
base-commit: 11e572d06c23d61683e20a98bd16f550ef17ac65
prerequisite-patch-id: 456044abe991b2ff3b521d337825432789d71b29
Comments
Hi!
> From: Patrick Rudolph <patrick.rudolph@9elements.com>
>
> max597x is hot swap controller with indicator LED support.
> This driver uses DT property to configure led during boot time &
> also provide the LED control in sysfs.
>
> DTS example:
> 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";
> };
> };
> };
> };
>
Yeah, well, dts bindings need to be properly documented, and example
goes to the binding, right?
Plus, we should have better names than led0/led1. Something like
hdd0:green:something, based on what the LED does and what are you hot
swapping. See/modify Documentation/leds/well-known-leds.txt .
> +static int max597x_led_set_brightness(struct led_classdev *cdev,
> + enum led_brightness brightness)
> +{
> + struct max597x_led *ddata = ldev_to_maxled(cdev);
> + int ret, val;
> +
> + if (!ddata->regmap)
> + return -ENODEV;
> +
> + /* Set/Clear corresponding bit for given led index */
"/clear".
> + val = !brightness ? BIT(ddata->index) : 0;
> + ret = regmap_update_bits(ddata->regmap, MAX5970_REG_LED_FLASH, BIT(ddata->index), val);
> + if (ret < 0)
> + dev_err(cdev->dev, "failed to set brightness %d", ret);
'\n"'.
> + ddata->cdev.brightness_set_blocking = max597x_led_set_brightness;
> + ddata->cdev.default_trigger = "none";
So what do these leds normally do? Should they be registered with
common function to handle default triggers etc?
> + ddata->index = reg;
> + ddata->regmap = regmap;
> + ret = devm_led_classdev_register(dev, &ddata->cdev);
> + if (ret)
> + dev_err(dev, "Error initializing LED %s", ddata->cdev.name);
'\n"'.
> +module_platform_driver(max597x_led_driver);
> +MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
> +MODULE_DESCRIPTION("MAX5970_hot-swap controller LED driver");
"MAX5970 hot-swap"?
> +MODULE_LICENSE("GPL");
>
> base-commit: 11e572d06c23d61683e20a98bd16f550ef17ac65
> prerequisite-patch-id: 456044abe991b2ff3b521d337825432789d71b29
?? Send prerequisites in the series?
BR,
Pavel
Hi Pavel,
On 13-04-2023 04:43 pm, Pavel Machek wrote:
> Hi!
>
>> From: Patrick Rudolph <patrick.rudolph@9elements.com>
>>
>> max597x is hot swap controller with indicator LED support.
>> This driver uses DT property to configure led during boot time &
>> also provide the LED control in sysfs.
>>
>> DTS example:
>> 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";
>> };
>> };
>> };
>> };
>>
>
> Yeah, well, dts bindings need to be properly documented, and example
> goes to the binding, right?
Yes.
>
> Plus, we should have better names than led0/led1. Something like
> hdd0:green:something, based on what the LED does and what are you hot
> swapping. See/modify Documentation/leds/well-known-leds.txt .
Yeah sure.
>
>
>> +static int max597x_led_set_brightness(struct led_classdev *cdev,
>> + enum led_brightness brightness)
>> +{
>> + struct max597x_led *ddata = ldev_to_maxled(cdev);
>> + int ret, val;
>> +
>> + if (!ddata->regmap)
>> + return -ENODEV;
>> +
>> + /* Set/Clear corresponding bit for given led index */
>
> "/clear".
Ack.
>
>> + val = !brightness ? BIT(ddata->index) : 0;
>> + ret = regmap_update_bits(ddata->regmap, MAX5970_REG_LED_FLASH, BIT(ddata->index), val);
>> + if (ret < 0)
>> + dev_err(cdev->dev, "failed to set brightness %d", ret);
>
> '\n"'.
Ack
>
>> + ddata->cdev.brightness_set_blocking = max597x_led_set_brightness;
>> + ddata->cdev.default_trigger = "none";
>
> So what do these leds normally do? Should they be registered with
> common function to handle default triggers etc?
Not sure if I understand your question right. In my use case in server
motherboards, they are use to indicate presence of power for individual
PCIe NVME connectors. Turning the LED on/off is handled by another
application based on some conditions.
>
>> + ddata->index = reg;
>> + ddata->regmap = regmap;
>> + ret = devm_led_classdev_register(dev, &ddata->cdev);
>> + if (ret)
>> + dev_err(dev, "Error initializing LED %s", ddata->cdev.name);
>
> '\n"'.
Ack
>
>> +module_platform_driver(max597x_led_driver);
>> +MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
>> +MODULE_DESCRIPTION("MAX5970_hot-swap controller LED driver");
>
> "MAX5970 hot-swap"?
max5970 is primarily a hotswap controller & it also had indication led
support.
>
>> +MODULE_LICENSE("GPL");
>>
>> base-commit: 11e572d06c23d61683e20a98bd16f550ef17ac65
>> prerequisite-patch-id: 456044abe991b2ff3b521d337825432789d71b29
>
> ?? Send prerequisites in the series?
Will fix in v5.
>
> BR,
> Pavel
Regards,
Naresh
@@ -590,6 +590,17 @@ config LEDS_ADP5520
To compile this driver as a module, choose M here: the module will
be called leds-adp5520.
+config LEDS_MAX597X
+ tristate "LED Support for Maxim 597x"
+ depends on LEDS_CLASS
+ depends on MFD_MAX597X
+ help
+ This option enables support for the Maxim MAX5970 & MAX5978 smart
+ switch indication LEDs via the I2C bus.
+
+ To compile this driver as a module, choose M here: the module will
+ be called leds-max597x.
+
config LEDS_MC13783
tristate "LED Support for MC13XXX PMIC"
depends on LEDS_CLASS
@@ -53,6 +53,7 @@ obj-$(CONFIG_LEDS_LP8501) += leds-lp8501.o
obj-$(CONFIG_LEDS_LP8788) += leds-lp8788.o
obj-$(CONFIG_LEDS_LP8860) += leds-lp8860.o
obj-$(CONFIG_LEDS_LT3593) += leds-lt3593.o
+obj-$(CONFIG_LEDS_MAX597X) += leds-max597x.o
obj-$(CONFIG_LEDS_MAX77650) += leds-max77650.o
obj-$(CONFIG_LEDS_MAX8997) += leds-max8997.o
obj-$(CONFIG_LEDS_MC13783) += leds-mc13783.o
new file mode 100644
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device driver for leds in MAX5970 and MAX5978 IC
+ *
+ * Copyright (c) 2022 9elements GmbH
+ *
+ * Author: Patrick Rudolph <patrick.rudolph@9elements.com>
+ */
+
+#include <linux/leds.h>
+#include <linux/mfd/max597x.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define ldev_to_maxled(c) container_of(c, struct max597x_led, cdev)
+
+struct max597x_led {
+ struct regmap *regmap;
+ struct led_classdev cdev;
+ unsigned int index;
+};
+
+static int max597x_led_set_brightness(struct led_classdev *cdev,
+ enum led_brightness brightness)
+{
+ struct max597x_led *ddata = ldev_to_maxled(cdev);
+ int ret, val;
+
+ if (!ddata->regmap)
+ return -ENODEV;
+
+ /* Set/Clear corresponding bit for given led index */
+ val = !brightness ? BIT(ddata->index) : 0;
+ ret = regmap_update_bits(ddata->regmap, MAX5970_REG_LED_FLASH, BIT(ddata->index), val);
+ if (ret < 0)
+ dev_err(cdev->dev, "failed to set brightness %d", ret);
+ return ret;
+}
+
+static int max597x_setup_led(struct device *dev, struct regmap *regmap, struct device_node *nc,
+ u32 reg)
+{
+ struct max597x_led *ddata;
+ int ret;
+
+ ddata = devm_kzalloc(dev, sizeof(struct max597x_led), GFP_KERNEL);
+ if (!ddata)
+ return -ENOMEM;
+
+ if (of_property_read_string(nc, "label", &ddata->cdev.name))
+ ddata->cdev.name = nc->name;
+
+ ddata->cdev.max_brightness = 1;
+ ddata->cdev.brightness_set_blocking = max597x_led_set_brightness;
+ ddata->cdev.default_trigger = "none";
+ ddata->index = reg;
+ ddata->regmap = regmap;
+ ret = devm_led_classdev_register(dev, &ddata->cdev);
+ if (ret)
+ dev_err(dev, "Error initializing LED %s", ddata->cdev.name);
+
+ return ret;
+}
+
+static int max597x_led_probe(struct platform_device *pdev)
+{
+ struct device_node *np = dev_of_node(pdev->dev.parent);
+ struct regmap *regmap;
+ struct device_node *led_node;
+ struct device_node *child;
+ int ret = 0;
+
+ regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ if (!regmap)
+ return -EPROBE_DEFER;
+
+ led_node = of_get_child_by_name(np, "leds");
+ if (!led_node)
+ return -ENODEV;
+
+ for_each_available_child_of_node(led_node, child) {
+ u32 reg;
+
+ if (of_property_read_u32(child, "reg", ®))
+ continue;
+
+ if (reg >= MAX597X_NUM_LEDS) {
+ dev_err(&pdev->dev, "invalid LED (%u >= %d)\n", reg,
+ MAX597X_NUM_LEDS);
+ continue;
+ }
+
+ ret = max597x_setup_led(&pdev->dev, regmap, child, reg);
+ if (ret < 0)
+ dev_err(&pdev->dev, "Failed to initialize LED %u\n", reg);
+ }
+
+ return ret;
+}
+
+static struct platform_driver max597x_led_driver = {
+ .driver = {
+ .name = "max597x-led",
+ },
+ .probe = max597x_led_probe,
+};
+
+module_platform_driver(max597x_led_driver);
+MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
+MODULE_DESCRIPTION("MAX5970_hot-swap controller LED driver");
+MODULE_LICENSE("GPL");