From: Grant Likely <grant.likely@secretlab.ca>
To: Bill Gatliff <bgat@billgatliff.com>
Cc: linux-embedded@vger.kernel.org
Subject: Re: [PWM 04/10] Implements PWM-based LED control
Date: Sat, 16 Oct 2010 01:58:24 -0600 [thread overview]
Message-ID: <20101016075824.GE653@angua.secretlab.ca> (raw)
In-Reply-To: <1285946271-17728-4-git-send-email-bgat@billgatliff.com>
On Fri, Oct 01, 2010 at 10:17:45AM -0500, Bill Gatliff wrote:
> Signed-off-by: Bill Gatliff <bgat@billgatliff.com>
Ditto on comment and patch title
> ---
> drivers/leds/Kconfig | 19 +++-
> drivers/leds/leds-pwm.c | 224 +++++++++++++++++++++++-------------------
> include/linux/pwm/pwm-led.h | 33 +++++++
> 3 files changed, 169 insertions(+), 107 deletions(-)
> create mode 100644 include/linux/pwm/pwm-led.h
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index e411262..3af2cde 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -26,12 +26,19 @@ config LEDS_88PM860X
> This option enables support for on-chip LED drivers found on Marvell
> Semiconductor 88PM8606 PMIC.
>
> -config LEDS_ATMEL_PWM
> - tristate "LED Support using Atmel PWM outputs"
> - depends on ATMEL_PWM
> - help
> - This option enables support for LEDs driven using outputs
> - of the dedicated PWM controller found on newer Atmel SOCs.
> +config LEDS_PWM
> + tristate "Support for LEDs connected to Generic PWM channels"
> + depends on LEDS_CLASS && GENERIC_PWM
> + help
> + Enables support for LEDs connected to PWM devices that
Inconsistent whitespace indentation
> + conform to the Generic PWM API. This API allows drivers
> + to adjust the brightness of the LED by varying the duty
> + cycle of the signal at the PWM channel output, using PWM API
> + commands, rather than merely turning them on and off.
> +
> + If your platform has devices with drivers that implement
> + the Generic PWM API, and those devices have outputs that
> + are connected to LEDs, then you probably want to say 'Y' here.
>
> config LEDS_LOCOMO
> tristate "LED Support for Locomo device"
> diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
> index da3fa8d..ab064ac 100644
> --- a/drivers/leds/leds-pwm.c
> +++ b/drivers/leds/leds-pwm.c
> @@ -1,153 +1,175 @@
> /*
> - * linux/drivers/leds-pwm.c
> + * drivers/leds/leds-pwm.c
> *
> - * simple PWM based LED control
> + * Copyright (C) 2010 Bill Gatliff <bgat@billgatliff.com>
> + * Copyright (C) 2009 Loutao Fu, Pengutronix <l.fu@pengutronix.de>
> *
> - * Copyright 2009 Luotao Fu @ Pengutronix (l.fu@pengutronix.de)
> + * Based on leds-gpio.c by Raphael Assenat <raph@8d.com>
> *
> - * based on leds-gpio.c by Raphael Assenat <raph@8d.com>
> - *
> - * This program is free software; you can redistribute it and/or modify
> - * it under the terms of the GNU General Public License version 2 as
> + * This program is Free Software. You may redistribute and/or modify
> + * it under the terms of the GNU General Public License version 2, as
> * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
> + * USA
> */
> -
> -#include <linux/module.h>
> #include <linux/kernel.h>
> -#include <linux/init.h>
> #include <linux/platform_device.h>
> -#include <linux/fb.h>
> -#include <linux/leds.h>
> -#include <linux/err.h>
> -#include <linux/pwm.h>
> -#include <linux/leds_pwm.h>
> #include <linux/slab.h>
> -
> -struct led_pwm_data {
> - struct led_classdev cdev;
> - struct pwm_device *pwm;
> - unsigned int active_low;
> - unsigned int period;
> +#include <linux/leds.h>
> +#include <linux/io.h>
> +#include <linux/pwm/pwm.h>
> +#include <linux/pwm/pwm-led.h>
> +
> +struct led_pwm {
> + struct led_classdev led;
> + struct pwm_channel *pwm;
> + int percent;
> };
Looks to be gratuitous modification. Changing the name of the
structure (led_pwm_data --> led_pwm) and changing cdev --> led makes
this diff very large for no good reason. If you really want to change
the names, then do it in a separate cleanup patch without functional
changes.
>
> -static void led_pwm_set(struct led_classdev *led_cdev,
> - enum led_brightness brightness)
Ditto here. Reformatting and renaming the function name just makes
the patch hard to review. Please repost without the unnecessary
rework (or at least split into a separate patch).
> +static inline struct led_pwm *to_led_pwm(const struct led_classdev *c)
> +{
> + return container_of(c, struct led_pwm, led);
> +}
> +
> +static void
> +led_pwm_brightness_set(struct led_classdev *c,
> + enum led_brightness b)
> +{
> + struct led_pwm *led = to_led_pwm(c);
> + int percent;
> +
> + percent = (b * 100) / (LED_FULL - LED_OFF);
> + led->percent = percent;
> + pwm_set_duty_percent(led->pwm, percent);
> +}
> +
> +static enum led_brightness
> +led_pwm_brightness_get(struct led_classdev *c)
> {
> - struct led_pwm_data *led_dat =
> - container_of(led_cdev, struct led_pwm_data, cdev);
> - unsigned int max = led_dat->cdev.max_brightness;
> - unsigned int period = led_dat->period;
> -
> - if (brightness == 0) {
> - pwm_config(led_dat->pwm, 0, period);
> - pwm_disable(led_dat->pwm);
> - } else {
> - pwm_config(led_dat->pwm, brightness * period / max, period);
> - pwm_enable(led_dat->pwm);
> + struct led_pwm *led = to_led_pwm(c);
> + return led->percent;
> +}
> +
> +static int
> +led_pwm_blink_set(struct led_classdev *c,
> + unsigned long *on_ms,
> + unsigned long *off_ms)
> +{
> + struct led_pwm *led = to_led_pwm(c);
> + struct pwm_channel_config cfg;
> +
> + if (*on_ms == 0 && *off_ms == 0) {
> + *on_ms = 1000UL;
> + *off_ms = 1000UL;
> }
> +
> + cfg.config_mask = PWM_CONFIG_DUTY_NS
> + | PWM_CONFIG_PERIOD_NS;
> +
> + cfg.duty_ns = *on_ms * 1000000UL;
> + cfg.period_ns = (*on_ms + *off_ms) * 1000000UL;
> +
> + return pwm_config(led->pwm, &cfg);
> }
>
> -static int led_pwm_probe(struct platform_device *pdev)
> +static int __devinit
> +led_pwm_probe(struct platform_device *pdev)
> {
> - struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
> - struct led_pwm *cur_led;
> - struct led_pwm_data *leds_data, *led_dat;
> - int i, ret = 0;
> + struct pwm_led_platform_data *pdata = pdev->dev.platform_data;
> + struct led_pwm *led;
> + int ret;
>
> - if (!pdata)
> - return -EBUSY;
> + if (!pdata || !pdata->led_info)
> + return -EINVAL;
>
> - leds_data = kzalloc(sizeof(struct led_pwm_data) * pdata->num_leds,
> - GFP_KERNEL);
> - if (!leds_data)
> + led = kzalloc(sizeof(*led), GFP_KERNEL);
> + if (!led)
> return -ENOMEM;
>
> - for (i = 0; i < pdata->num_leds; i++) {
> - cur_led = &pdata->leds[i];
> - led_dat = &leds_data[i];
> -
> - led_dat->pwm = pwm_request(cur_led->pwm_id,
> - cur_led->name);
> - if (IS_ERR(led_dat->pwm)) {
> - dev_err(&pdev->dev, "unable to request PWM %d\n",
> - cur_led->pwm_id);
> - goto err;
> - }
> -
> - led_dat->cdev.name = cur_led->name;
> - led_dat->cdev.default_trigger = cur_led->default_trigger;
> - led_dat->active_low = cur_led->active_low;
> - led_dat->period = cur_led->pwm_period_ns;
> - led_dat->cdev.brightness_set = led_pwm_set;
> - led_dat->cdev.brightness = LED_OFF;
> - led_dat->cdev.max_brightness = cur_led->max_brightness;
> - led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
> -
> - ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
> - if (ret < 0) {
> - pwm_free(led_dat->pwm);
> - goto err;
> - }
> + led->pwm = pwm_request(pdata->bus_id, pdata->chan,
> + pdata->led_info->name);
> + if (!led->pwm) {
> + ret = -EINVAL;
> + goto err_pwm_request;
> }
>
> - platform_set_drvdata(pdev, leds_data);
> + platform_set_drvdata(pdev, led);
>
> - return 0;
> + led->led.name = pdata->led_info->name;
> + led->led.default_trigger = pdata->led_info->default_trigger;
> + led->led.brightness_set = led_pwm_brightness_set;
> + led->led.brightness_get = led_pwm_brightness_get;
> + led->led.blink_set = led_pwm_blink_set;
> + led->led.brightness = LED_OFF;
>
> -err:
> - if (i > 0) {
> - for (i = i - 1; i >= 0; i--) {
> - led_classdev_unregister(&leds_data[i].cdev);
> - pwm_free(leds_data[i].pwm);
> - }
> - }
> + ret = pwm_config(led->pwm, pdata->config);
> + if (ret)
> + goto err_pwm_config;
> + pwm_start(led->pwm);
> +
> + ret = led_classdev_register(&pdev->dev, &led->led);
> + if (ret < 0)
> + goto err_classdev_register;
>
> - kfree(leds_data);
> + return 0;
> +
> +err_classdev_register:
> + pwm_stop(led->pwm);
> +err_pwm_config:
> + pwm_release(led->pwm);
> +err_pwm_request:
> + kfree(led);
>
> return ret;
> }
>
> -static int __devexit led_pwm_remove(struct platform_device *pdev)
> +static int __devexit
> +led_pwm_remove(struct platform_device *pdev)
> {
> - int i;
> - struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
> - struct led_pwm_data *leds_data;
> + struct led_pwm *led = platform_get_drvdata(pdev);
>
> - leds_data = platform_get_drvdata(pdev);
> + led_classdev_unregister(&led->led);
>
> - for (i = 0; i < pdata->num_leds; i++) {
> - led_classdev_unregister(&leds_data[i].cdev);
> - pwm_free(leds_data[i].pwm);
> + if (led->pwm) {
> + pwm_stop(led->pwm);
> + pwm_release(led->pwm);
> }
>
> - kfree(leds_data);
> + kfree(led);
>
> return 0;
> }
>
> static struct platform_driver led_pwm_driver = {
> - .probe = led_pwm_probe,
> - .remove = __devexit_p(led_pwm_remove),
> - .driver = {
> - .name = "leds_pwm",
> - .owner = THIS_MODULE,
> + .driver = {
> + .name = "leds-pwm",
> + .owner = THIS_MODULE,
> },
> + .probe = led_pwm_probe,
> + .remove = led_pwm_remove,
> };
>
> -static int __init led_pwm_init(void)
> +static int __init led_pwm_modinit(void)
> {
> return platform_driver_register(&led_pwm_driver);
> }
> +module_init(led_pwm_modinit);
>
> -static void __exit led_pwm_exit(void)
> +static void __exit led_pwm_modexit(void)
> {
> platform_driver_unregister(&led_pwm_driver);
> }
> +module_exit(led_pwm_modexit);
>
> -module_init(led_pwm_init);
> -module_exit(led_pwm_exit);
> -
> -MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
> -MODULE_DESCRIPTION("PWM LED driver for PXA");
> +MODULE_AUTHOR("Bill Gatliff <bgat@billgatliff.com>");
> +MODULE_DESCRIPTION("Driver for LEDs with PWM-controlled brightness");
> MODULE_LICENSE("GPL");
> MODULE_ALIAS("platform:leds-pwm");
> diff --git a/include/linux/pwm/pwm-led.h b/include/linux/pwm/pwm-led.h
> new file mode 100644
> index 0000000..8ffeecc
> --- /dev/null
> +++ b/include/linux/pwm/pwm-led.h
> @@ -0,0 +1,33 @@
> +/*
> + * include/linux/pwm-led.h
> + *
> + * Copyright (C) 2008 Bill Gatliff <bgat@billgatliff.com>
> + *
> + * This program is free software; you may redistribute and/or modify
> + * it under the terms of the GNU General Public License version 2, as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
> + * USA
> + */
> +#ifndef __LINUX_PWM_LED_H
> +#define __LINUX_PWM_LED_H
> +
> +struct led_info;
> +struct pwm_channel_config;
> +
> +struct pwm_led_platform_data {
> + const char *bus_id;
> + int chan;
> + struct pwm_channel_config *config;
> + struct led_info *led_info;
> +};
> +
> +#endif /* __LINUX_PWM_LED_H */
> --
> 1.7.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-embedded" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2010-10-16 7:58 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-01 15:17 [PWM 01/10] API to consolidate PWM devices behind a common user and kernel interface Bill Gatliff
2010-10-01 15:17 ` [PWM 02/10] Emulates PWM hardware using a high-resolution timer and a GPIO pin Bill Gatliff
2010-10-16 6:54 ` Grant Likely
2010-10-01 15:17 ` [PWM 03/10] Expunge old Atmel PWMC driver, replacing it with one that conforms to the PWM API Bill Gatliff
2010-10-16 7:50 ` Grant Likely
2010-10-01 15:17 ` [PWM 04/10] Implements PWM-based LED control Bill Gatliff
2010-10-16 7:58 ` Grant Likely [this message]
2010-10-01 15:17 ` [PWM 05/10] LED "dim" trigger based on PWM control of the LED Bill Gatliff
2010-10-16 8:00 ` Grant Likely
2010-10-01 15:17 ` [PWM 06/10] Incorporate PWM API code into KBuild Bill Gatliff
2010-10-16 8:02 ` Grant Likely
2010-10-19 2:17 ` Bill Gatliff
2010-10-01 15:17 ` [PWM 07/10] PWM API driver for MPC52xx GPT peripheral Bill Gatliff
2010-10-01 15:17 ` [PWM 08/10] Initial support for PXA PWM peripheral; compile-tested only Bill Gatliff
2010-10-01 15:17 ` Bill Gatliff
2010-10-01 15:17 ` [PWM 09/10] Build pwm.o only if CONFIG_GENERIC_PWM is set Bill Gatliff
2010-10-01 15:17 ` [PWM 10/10] Expunge previous driver for PXA PWM Bill Gatliff
2010-10-01 22:00 ` [PWM 01/10] API to consolidate PWM devices behind a common user and kernel interface Kevin Hilman
2010-10-02 5:13 ` Jason Kridner
2010-10-06 18:45 ` Bill Gatliff
2010-10-06 19:08 ` Kevin Hilman
2010-10-02 12:25 ` Hector Oron
2010-10-06 18:48 ` Bill Gatliff
2010-10-16 6:05 ` Grant Likely
2010-10-05 10:35 ` sugumar
2010-10-06 18:50 ` Bill Gatliff
2010-10-06 19:02 ` Grosen, Mark
2010-10-07 7:58 ` Sugumar Natarajan
2010-10-16 7:42 ` Grant Likely
2010-10-20 18:13 ` Bill Gatliff
2010-10-20 18:34 ` Grant Likely
2010-10-20 19:32 ` Bill Gatliff
2010-10-21 13:18 ` Bill Gatliff
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20101016075824.GE653@angua.secretlab.ca \
--to=grant.likely@secretlab.ca \
--cc=bgat@billgatliff.com \
--cc=linux-embedded@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).