Hi Vadim,
Thanks for the patch. Please refer to my remarks in the code below.
On 07/25/2017 06:54 PM, Vadim Pasternak wrote:
> Driver obtains LED devices according to system configuration, provided
> through the platform data,
Why platform data? This is confusing since you're providing DT bindings
in 1/2.
> like mlxreg:status:green or mlxreg:status:amber
> and creates devices in form: "devicename:colour:function".
> The full path is to be:
> /sys/class/leds/mlxreg\:status\:amber/brightness
> After timer trigger activation:
> echo timer > /sys/class/leds/mlxreg\:status\:amber/trigger
> Attributes for LED blinking will appaer in sysfs infrastructure:
> /sys/class/leds/mlxreg\:status\:amber/delay_off
> /sys/class/leds/mlxreg\:status\:amber/delay_on
>
> LED setting is controlled through the on-board programmable devices,
> which exports its register map. This device could be attached to any
> bus type, for which register mapping is supported.
>
> Signed-off-by: Vadim Pasternak <vadimp@xxxxxxxxxxxx>
> ---
> MAINTAINERS | 1 +
> drivers/leds/Makefile | 1 +
> drivers/leds/leds-mlxreg.c | 345 +++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 347 insertions(+)
> create mode 100644 drivers/leds/leds-mlxreg.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 205d397..ac6b0d0 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8566,6 +8566,7 @@ M: Vadim Pasternak <vadimp@xxxxxxxxxxxx>
> L: linux-leds@xxxxxxxxxxxxxxx
> S: Supported
> F: drivers/leds/leds-mlxcpld.c
> +F: drivers/leds/leds-mlxreg.c
> F: Documentation/leds/leds-mlxcpld.txt
>
> MELLANOX PLATFORM DRIVER
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 909dae6..3eb76e5 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -69,6 +69,7 @@ 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-$(CONFIG_LEDS_MLXREG) += leds-mlxreg.o
> obj-$(CONFIG_LEDS_NIC78BX) += leds-nic78bx.o
> obj-$(CONFIG_LEDS_MT6323) += leds-mt6323.o
>
> diff --git a/drivers/leds/leds-mlxreg.c b/drivers/leds/leds-mlxreg.c
> new file mode 100644
> index 0000000..bc1a6c3
> --- /dev/null
> +++ b/drivers/leds/leds-mlxreg.c
> @@ -0,0 +1,345 @@
> +/*
> + * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
> + * Copyright (c) 2017 Vadim Pasternak <vadimp@xxxxxxxxxxxx>
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions are met:
> + *
> + * 1. Redistributions of source code must retain the above copyright
> + * notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + * notice, this list of conditions and the following disclaimer in the
> + * documentation and/or other materials provided with the distribution.
> + * 3. Neither the names of the copyright holders nor the names of its
> + * contributors may be used to endorse or promote products derived from
> + * this software without specific prior written permission.
> + *
> + * Alternatively, this software may be distributed under the terms of the
> + * GNU General Public License ("GPL") version 2 as published by the Free
> + * Software Foundation.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
> + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
> + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
> + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
> + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
> + * POSSIBILITY OF SUCH DAMAGE.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/device.h>
> +#include <linux/interrupt.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/io.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_data/mlxreg.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/wait.h>
> +#include <linux/workqueue.h>
> +
> +#define MLXREG_LED_NAME "mlxreg"
Why can't it be taken from DT?
> +
> +/* Codes for LEDs. */
> +#define MLXREG_LED_OFFSET_HALF 0x01 /* Offset from solid: 3Hz blink */
> +#define MLXREG_LED_OFFSET_FULL 0x02 /* Offset from solid: 6Hz blink */
> +#define MLXREG_LED_IS_OFF 0x00 /* Off */
> +#define MLXREG_LED_RED_SOLID 0x05 /* Solid red */
> +#define MLXREG_LED_GREEN_SOLID 0x0D /* Solid green */
> +#define MLXREG_LED_AMBER_SOLID 0x09 /* Solid amber */
> +#define MLXREG_LED_BLINK_3HZ 167 /* ~167 msec off/on - HW support */
> +#define MLXREG_LED_BLINK_6HZ 83 /* ~83 msec off/on - HW support */
> +#define MLXREG_LED_MAX_DEFERRED 32 /* Max deferred operations for LED set */
> +
> +#define cdev_to_priv(c) container_of(c, struct mlxreg_core_led_data, led_cdev)
> +
> +/**
> + * struct mlxreg_led_priv_data - platform private data:
> + *
> + * @pdev: platform device;
> + * @pdata: platform data;
> + * @access_lock: mutex for attribute IO access;
> + */
> +struct mlxreg_led_priv_data {
> + struct platform_device *pdev;
> + struct mlxreg_core_led_platform_data *pdata;
> + struct mutex access_lock; /* protect IO operations */
> +};
> +
> +#define MLXREG_MAP priv->pdata->regmap
> +
> +static int
> +mlxreg_led_store_hw(struct mlxreg_core_led_data *led_pdata, u8 vset)
> +{
> + struct mlxreg_led_priv_data *priv = led_pdata->data_parent;
> + u32 regval;
> + u32 nib;
> + int ret;
> +
> + /*
> + * Each LED is controlled through low or high nibble of the relevant
> + * register byte. Register offset is specified by off parameter.
> + * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
> + * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
> + * green.
> + * Parameter mask specifies which nibble is used for specific LED: mask
> + * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
> + * higher nibble (bits from 4 to 7).
> + */
> + mutex_lock(&priv->access_lock);
> +
> + ret = regmap_read(MLXREG_MAP, led_pdata->led->reg, ®val);
> + if (ret)
> + goto access_error;
> +
> + nib = (ror32(led_pdata->led->mask, led_pdata->led->bit) == 0xf0) ?
> + rol32(vset, led_pdata->led->bit) :
> + rol32(vset, led_pdata->led->bit + 4);
> + regval = (regval & led_pdata->led->mask) | nib;
> +
> + ret = regmap_write(MLXREG_MAP, led_pdata->led->reg, regval);
> +
> +access_error:
> + mutex_unlock(&priv->access_lock);
> +
> + return ret;
> +}
> +
> +static enum led_brightness
> +mlxreg_led_get_hw(struct mlxreg_core_led_data *led_pdata)
> +{
> + struct mlxreg_led_priv_data *priv = led_pdata->data_parent;
> + u32 regval;
> + int ret;
> +
> + /*
> + * Each LED is controlled through low or high nibble of the relevant
> + * register byte. Register offset is specified by off parameter.
> + * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
> + * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
> + * green.
> + * Parameter mask specifies which nibble is used for specific LED: mask
> + * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
> + * higher nibble (bits from 4 to 7).
> + */
> + ret = regmap_read(MLXREG_MAP, led_pdata->led->reg, ®val);
> + if (ret < 0) {
> + dev_warn(led_pdata->led_cdev.dev, "Failed to get current brightness, error: %d\n",
> + ret);
> + /* Assume the LED is OFF */
> + ret = LED_OFF;
> + goto access_error;
> + }
> +
> + regval = regval & ~led_pdata->led->mask;
> + regval = (ror32(led_pdata->led->mask, led_pdata->led->bit) == 0xf0) ?
> + ror32(regval, led_pdata->led->bit) :
> + ror32(regval, led_pdata->led->bit + 4);
> + if (regval >= led_pdata->base_color &&
> + regval <= (led_pdata->base_color + MLXREG_LED_OFFSET_FULL))
> + ret = LED_FULL;
> + else
> + ret = LED_OFF;
> +
> +access_error:
> +
> + return ret;
> +}
> +
> +static void
> +mlxreg_led_brightness_set(struct led_classdev *cled, enum led_brightness value)
> +{
> + struct mlxreg_core_led_data *led_pdata = cdev_to_priv(cled);
> +
> + if (in_interrupt()) {
You wouldn't have to bother with the context you are called from if only
you used brightness_set_blocking op.
> + /*
> + * Handle hw access to LED in workqueue to avoid I2C locking in
> + * interrupt mode. Skip if deferred operations counter is at
> + * maximum value.
> + */
> + if (led_pdata->set_count == MLXREG_LED_MAX_DEFERRED - 1)
> + return;
> +
> + if (!!value)
> + led_pdata->bitset |= BIT(led_pdata->set_count);
> + led_pdata->set_count++;
> +
> + schedule_delayed_work(&led_pdata->dwork_led, 0);
Similarly you could get rid of the workqueue then. It is implemented
internally in the LED core now.
> +
> + return;
> + }
> +
> + if (value)
> + mlxreg_led_store_hw(led_pdata, led_pdata->base_color);
> + else
> + mlxreg_led_store_hw(led_pdata, MLXREG_LED_IS_OFF);
> +}
> +
> +static enum led_brightness
> +mlxreg_led_brightness_get(struct led_classdev *cled)
> +{
> + struct mlxreg_core_led_data *led_pdata = cdev_to_priv(cled);
> +
> + return mlxreg_led_get_hw(led_pdata);
> +}
> +
> +static int
> +mlxreg_led_blink_set(struct led_classdev *cled, unsigned long *delay_on,
> + unsigned long *delay_off)
> +{
> + struct mlxreg_core_led_data *led_pdata = cdev_to_priv(cled);
> + int err;
> +
> + /*
> + * HW supports two types of blinking: full (6Hz) and half (3Hz).
> + * For delay on/off zero LED is setting to solid color. For others
> + * combination blinking is to be controlled by the software timer.
> + */
> + if (!(*delay_on == 0 && *delay_off == 0) &&
> + !(*delay_on == MLXREG_LED_BLINK_3HZ &&
> + *delay_off == MLXREG_LED_BLINK_3HZ) &&
> + !(*delay_on == MLXREG_LED_BLINK_6HZ &&
> + *delay_off == MLXREG_LED_BLINK_6HZ))
> + return -EINVAL;
> +
> + if (*delay_on == MLXREG_LED_BLINK_6HZ)
> + err = mlxreg_led_store_hw(led_pdata, led_pdata->base_color +
> + MLXREG_LED_OFFSET_FULL);
> + else if (*delay_on == MLXREG_LED_BLINK_3HZ)
> + err = mlxreg_led_store_hw(led_pdata, led_pdata->base_color +
> + MLXREG_LED_OFFSET_HALF);
> + else
> + err = mlxreg_led_store_hw(led_pdata, led_pdata->base_color);
> +
> + return err;
> +}
> +
> +static void mlxreg_led_handler(struct work_struct *work)
> +{
> + struct mlxreg_core_led_data *led_pdata = container_of(work,
> + struct mlxreg_core_led_data, dwork_led.work);
> +
> + if (led_pdata->bitset & BIT(0))
> + mlxreg_led_store_hw(led_pdata, led_pdata->base_color);
> + else
> + mlxreg_led_store_hw(led_pdata, MLXREG_LED_IS_OFF);
> +
> + led_pdata->bitset >>= 1;
> + led_pdata->set_count--;
> +}
> +
> +#define MLXREG_CDEV(i) pdata->data[i].led_cdev
> +
> +static int mlxreg_led_config(struct mlxreg_led_priv_data *priv)
> +{
> + struct mlxreg_core_led_platform_data *pdata = priv->pdata;
> + struct mlxreg_core_data *data = pdata->data->led;
> + int brightness;
> + int i;
> + int err;
> +
> + for (i = 0; i < pdata->counter; i++, data++) {
> + pdata->data[i].data_parent = priv;
> + if (strstr(data->label, "red")) {
> + brightness = LED_OFF;
> + pdata->data[i].base_color = MLXREG_LED_RED_SOLID;
> + } else if (strstr(data->label, "amber")) {
> + brightness = LED_OFF;
> + pdata->data[i].base_color = MLXREG_LED_AMBER_SOLID;
> + } else {
> + brightness = LED_OFF;
> + pdata->data[i].base_color = MLXREG_LED_GREEN_SOLID;
> + }
> + sprintf(pdata->data[i].led_cdev_name, "%s:%s",
> + MLXREG_LED_NAME, data->label);
You should take LED name directly from the of_node. Either child DT
node name or label property contained by it.
See Documentation/devicetree/bindings/leds/common.txt.
> + MLXREG_CDEV(i).name = pdata->data[i].led_cdev_name;
Let's avoid using these type of macros in favor of temporary
variables. However let's agree about final shape thereof after core mfd
driver gets reviewed.
> + MLXREG_CDEV(i).brightness = brightness;
> + MLXREG_CDEV(i).max_brightness = 1;
> + MLXREG_CDEV(i).brightness_set = mlxreg_led_brightness_set;
> + MLXREG_CDEV(i).brightness_get = mlxreg_led_brightness_get;
> + MLXREG_CDEV(i).blink_set = mlxreg_led_blink_set;
> + MLXREG_CDEV(i).flags = LED_CORE_SUSPENDRESUME;
> + pdata->data[i].led = data;
> + err = devm_led_classdev_register(&priv->pdev->dev,
> + &MLXREG_CDEV(i));
> + if (err)
> + return err;
> +
> + if (MLXREG_CDEV(i).brightness)
> + mlxreg_led_brightness_set(
> + &MLXREG_CDEV(i),
> + MLXREG_CDEV(i).brightness);
> + dev_info(MLXREG_CDEV(i).dev,
> + "label: %s, mask: 0x%02x, offset:0x%02x\n",
> + data->label, data->mask, data->reg);
> +
> + INIT_DELAYED_WORK(&pdata->data[i].dwork_led,
> + mlxreg_led_handler);
> + }
> +
> + return 0;
> +}
> +
> +static int mlxreg_led_probe(struct platform_device *pdev)
> +{
> + struct mlxreg_core_led_platform_data *pdata;
> + struct mlxreg_led_priv_data *priv;
> +
> + pdata = dev_get_platdata(&pdev->dev);
> + if (!pdata) {
> + dev_err(&pdev->dev, "Failed to get platform data.\n");
> + return -EINVAL;
> + }
> +
> + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + mutex_init(&priv->access_lock);
> + priv->pdev = pdev;
> + priv->pdata = pdata;
> +
> + return mlxreg_led_config(priv);
> +}
> +
> +static int mlxreg_led_remove(struct platform_device *pdev)
> +{
> + struct mlxreg_led_priv_data *priv = dev_get_drvdata(&pdev->dev);
> + struct mlxreg_core_led_platform_data *pdata = priv->pdata;
> + int i;
> +
> + for (i = 0; i < pdata->counter; i++)
> + cancel_delayed_work(&pdata->data[i].dwork_led);
> +
> + mutex_unlock(&priv->access_lock);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id mlxreg_led_dt_match[] = {
> + { .compatible = "mellanox,leds-mlxreg" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, mlxreg_dt_match);
> +
> +static struct platform_driver mlxreg_led_driver = {
> + .driver = {
> + .name = "leds-mlxreg",
> + .of_match_table = of_match_ptr(mlxreg_led_dt_match),
> + },
> + .probe = mlxreg_led_probe,
> + .remove = mlxreg_led_remove,
> +};
> +
> +module_platform_driver(mlxreg_led_driver);
> +
> +MODULE_AUTHOR("Vadim Pasternak <vadimp@xxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Mellanox LED regmap driver");
> +MODULE_LICENSE("Dual BSD/GPL");
> +MODULE_ALIAS("platform:leds-mlxreg");
>
--
Best regards,
Jacek Anaszewski
