Hi Pantelis,

Thanks for the patch. Please find my comments in the code below.

On 10/07/2016 05:21 PM, Pantelis Antoniou wrote:

Please arrange include directives in alphabetical order.

+#define FRU_LEDS	4 /* Total LEDs (active, fail, ok, standby) */
+#define HW_BLINK_LEDS	3 /* LEDs with hw blink cap (standby not supported) */
+
+/*
+ * I2CS fru_led [0x12]
+ *
+ * bit 6   | bit 5    | bit 4   |...                        | bit 0
+ * blink_ok|blink_fail|blink_act|led_standby|led_ok|led_fail|led_act
+ */
+
+/* TODO: Use the regmap from the parent MFD */

Isn't it a good moment to address that?

+static struct regmap_config i2cs_leds_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = I2CS_SPARE_OE,
+};
+
+struct i2cs_led {
+	struct led_classdev lc;

Most drivers use led_cdev or cdev name for it.
It is more informative and improves readability.

+	struct regmap *regmap;
+	struct work_struct work;
+	int blink;
+	int on;
+	int bit;
+};
+
+struct i2cs_led_data {
+	int num_leds;
+	struct i2cs_led *leds;
+};
+
+static void jnx_i2cs_leds_work(struct work_struct *work)
+{
+	struct i2cs_led *led = container_of(work, struct i2cs_led, work);
+
+	int mask = (BIT(led->bit) << 4) | BIT(led->bit);
+	int value = ((led->blink << led->bit) << 4) | (led->on << led->bit);
+
+	regmap_update_bits(led->regmap, I2CS_FRU_LED, mask, value & 0x7f);
+}

If you used brightness_set_blocking op instead of brightness_set,
then you could get rid of the in-driver work queue.

+
+static void jnx_i2cs_leds_brightness_set(struct led_classdev *lc,
+				 enum led_brightness brightness)
+{
+	struct i2cs_led *led = container_of(lc, struct i2cs_led, lc);
+
+	led->on = (brightness != LED_OFF);
+	led->blink = 0; /* always turn off hw blink on brightness_set() */

Some time ago we changed brightness setting semantics when blinking
is on. Now setting any brightness > 0 shouldn't disable blinking.
Following commit provides the details:

7cfe749fad51 ("leds: core: Fix brightness setting upon hardware blinking 
enabled")

It seems that the hardware supports only one brightness level.
In such a case I'd return immediately if the LED is on and
brightness to be set is 1.

+	schedule_work(&led->work);
+}
+
+static int jnx_i2cs_leds_blink_set(struct led_classdev *lc,
+				   unsigned long *delay_on,
+				   unsigned long *delay_off)
+{
+	struct i2cs_led *led = container_of(lc, struct i2cs_led, lc);
+
+	led->blink = (*delay_on > 0);

blink_set op should fail if hardware doesn't support delay_on
or delay_off periods. I lets the LED core to apply software blink
fallback.

+	led->on = led->blink; /* 'on' bit should be set if blinking */
+	schedule_work(&led->work);
+
+	return 0;
+}
+
+static int jnx_i2cs_leds_init_one(struct device *dev, struct device_node *np,
+				  struct i2cs_led_data *ild,
+				  struct regmap *regmap, int num)
+{
+	struct i2cs_led *led;
+	const char *string;
+	bool hw_blink;
+	int ret;
+	u32 reg;
+
+	ret = of_property_read_u32(np, "reg", &reg);
+	if (ret || reg >= FRU_LEDS)
+		return -ENODEV;
+
+	led = &ild->leds[num];
+	led->bit = reg;
+	led->regmap = regmap;
+
+	if (!of_property_read_string(np, "label", &string))
+		led->lc.name = string;
+	else
+		led->lc.name = np->name;
+
+	if (!of_property_read_string(np, "linux,default-trigger", &string))
+		led->lc.default_trigger = string;
+
+	led->lc.brightness = LED_OFF;
+	led->lc.brightness_set = jnx_i2cs_leds_brightness_set;

You need also:

led->lc.max_brightness = 1;

+	if (led->bit <= HW_BLINK_LEDS) {
+		hw_blink = of_property_read_bool(np, "hw-blink");
+		if (hw_blink)
+			led->lc.blink_set = jnx_i2cs_leds_blink_set;
+	}
+
+	ret = devm_led_classdev_register(dev, &led->lc);
+	if (ret)
+		return ret;
+
+	INIT_WORK(&led->work, jnx_i2cs_leds_work);
+
+	return 0;
+}
+
+static int jnx_i2cs_leds_of_init(struct device *dev, struct i2cs_led_data *ild)
+{
+	struct device_node *child, *np = dev->of_node;
+	struct regmap *regmap;
+	struct i2c_client *client;
+	int ret, num_leds, i = 0;
+
+	if (!dev->parent)
+		return -ENODEV;
+
+	client = i2c_verify_client(dev->parent);
+	if (!client)
+		return -ENODEV;
+
+	regmap = devm_regmap_init_i2c(client, &i2cs_leds_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(dev, "Failed to allocate register map\n");
+		return PTR_ERR(regmap);
+	}
+
+	num_leds = of_get_child_count(np);
+	if (!num_leds || num_leds > FRU_LEDS)
+		return -ENODEV;
+
+	ild->num_leds = num_leds;
+	ild->leds = devm_kzalloc(dev, sizeof(struct i2cs_led) * num_leds,
+				 GFP_KERNEL);
+	if (!ild->leds)
+		return -ENOMEM;
+
+	for_each_child_of_node(np, child) {
+		ret = jnx_i2cs_leds_init_one(dev, child, ild, regmap, i++);
+		if (ret)
+			return ret;

of_node_put(child) should be called on error to avoid memory leak.

+	}
+
+	return 0;
+}
+
+static int jnx_i2cs_leds_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct i2cs_led_data *ild;
+	int ret;
+
+	ild = devm_kzalloc(dev, sizeof(*ild), GFP_KERNEL);
+	if (!ild)
+		return -ENOMEM;
+
+	ret = jnx_i2cs_leds_of_init(dev, ild);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, ild);
+
+	return 0;
+}
+
+static int jnx_i2cs_leds_remove(struct platform_device *pdev)
+{
+	struct i2cs_led_data *ild = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < ild->num_leds; i++) {
+		devm_led_classdev_unregister(&pdev->dev, &ild->leds[i].lc);

This is redundant.

+		cancel_work_sync(&ild->leds[i].work);
+	}
+
+	return 0;
+}

This function will be redundant after removing work queue.

+static const struct of_device_id jnx_i2cs_leds_match[] = {
+	{ .compatible = "jnx,leds-i2cs", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, jnx_i2cs_leds_match);
+
+static struct platform_driver jnx_i2cs_leds_driver = {
+	.driver = {
+		.name  = "leds-i2cs",
+		.of_match_table = jnx_i2cs_leds_match,
+	},
+	.probe = jnx_i2cs_leds_probe,
+	.remove = jnx_i2cs_leds_remove,
+};
+
+module_platform_driver(jnx_i2cs_leds_driver);
+
+MODULE_DESCRIPTION("Juniper Networks I2CS leds driver");
+MODULE_AUTHOR("Georgi Vlaev [off-list ref]");
+MODULE_LICENSE("GPL");

-- 
Best regards,
Jacek Anaszewski