Re: [PATCH 07/10] leds: i2cs: Add I2CS FPGA leds driver
From: Jacek Anaszewski
Date: Mon Oct 10 2016 - 05:41:53 EST
Hi Pantelis,
Thanks for the patch. Please find my comments in the code below.
On 10/07/2016 05:21 PM, Pantelis Antoniou wrote:
From: Georgi Vlaev <gvlaev@xxxxxxxxxxx>
Add support for the FRU faceplate status LEDs (OK, FAIL,
ACTIVE, STANDBY) controlled by the Juniper I2CS FPGA. This
driver is a jnx-i2cs-core client.
Signed-off-by: Georgi Vlaev <gvlaev@xxxxxxxxxxx>
[Ported from Juniper kernel]
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
---
drivers/leds/Kconfig | 9 ++
drivers/leds/Makefile | 1 +
drivers/leds/leds-jnx-i2cs.c | 219 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 229 insertions(+)
create mode 100644 drivers/leds/leds-jnx-i2cs.c
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 7a628c6..45c6612 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -659,6 +659,15 @@ config LEDS_MLXCPLD
This option enabled support for the LEDs on the Mellanox
boards. Say Y to enabled these.
+config LEDS_JNX_I2CS
+ tristate "LED support for the Juniper Networks I2CS FPGA"
+ depends on LEDS_CLASS && I2C
+ select REGMAP_I2C
+ help
+ This option enables support for the FRU faceplate status
+ LEDs (OK, FAIL, ACTIVE, STANDBY) controlled by the Juniper
+ I2CS FPGA.
+
comment "LED Triggers"
source "drivers/leds/trigger/Kconfig"
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 3965070..1ce2d0b 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -71,6 +71,7 @@ obj-$(CONFIG_LEDS_IS31FL319X) += leds-is31fl319x.o
obj-$(CONFIG_LEDS_IS31FL32XX) += leds-is31fl32xx.o
obj-$(CONFIG_LEDS_PM8058) += leds-pm8058.o
obj-$(CONFIG_LEDS_MLXCPLD) += leds-mlxcpld.o
+obj-$(CONFIG_LEDS_JNX_I2CS) += leds-jnx-i2cs.o
# LED SPI Drivers
obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o
diff --git a/drivers/leds/leds-jnx-i2cs.c b/drivers/leds/leds-jnx-i2cs.c
new file mode 100644
index 0000000..c2d7274
--- /dev/null
+++ b/drivers/leds/leds-jnx-i2cs.c
@@ -0,0 +1,219 @@
+/*
+ * Juniper Networks I2CS FPGA LEDs driver
+ *
+ * Copyright (C) 2016 Juniper Networks
+ * Author: Georgi Vlaev <gvlaev@xxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/of.h>
+#include <linux/delay.h>
+#include <linux/leds.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/jnx-i2cs-core.h>
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", ®);
+ 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 <gvlaev@xxxxxxxxxxx>");
+MODULE_LICENSE("GPL");
--
Best regards,
Jacek Anaszewski