Re: [PATCH 4/7] rtc: PCF50633 rtc driver

[Alessandro Zummo <alessandro.zummo@towertech.it>]

On Sun, 14 Dec 2008 16:33:05 +0530
Balaji Rao <balajirrao@openmoko.org> wrote:

 Hello,

  first review below. Please always add the rtc-linux mailing
 list in cc so that patchwork[1] can track your submission.

[1]
 http://patchwork.ozlabs.org/project/rtc-linux/list/?state=*

> Signed-off-by: Balaji Rao <balajirrao@openmoko.org>
> Cc: Andy Green <andy@openmoko.com>
> Cc: Alessandro Zummo <a.zummo@towertech.it>
> Cc: Paul Gortmaker <a.zummo@towertech.it>
> ---
>  drivers/rtc/Kconfig        |    6 +
>  drivers/rtc/Makefile       |    1 
>  drivers/rtc/rtc-pcf50633.c |  302 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 309 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/rtc/rtc-pcf50633.c
> 
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index 123092d..68e68d2 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -497,6 +497,12 @@ config RTC_DRV_WM8350
>  	  This driver can also be built as a module. If so, the module
>  	  will be called "rtc-wm8350".
>  
> +config RTC_DRV_PCF50633
> +	depends on MFD_PCF50633
> +	tristate "NXP PCF50633 RTC"
> +	help
> +	  If you say yes here you get support for the NXP PCF50633 RTC.
> +
>  comment "on-CPU RTC drivers"
>  
>  config RTC_DRV_OMAP
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index 6e79c91..a717fec 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -70,3 +70,4 @@ obj-$(CONFIG_RTC_DRV_V3020)	+= rtc-v3020.o
>  obj-$(CONFIG_RTC_DRV_VR41XX)	+= rtc-vr41xx.o
>  obj-$(CONFIG_RTC_DRV_WM8350)	+= rtc-wm8350.o
>  obj-$(CONFIG_RTC_DRV_X1205)	+= rtc-x1205.o
> +obj-$(CONFIG_RTC_DRV_PCF50633)	+= rtc-pcf50633.o
> diff --git a/drivers/rtc/rtc-pcf50633.c b/drivers/rtc/rtc-pcf50633.c
> new file mode 100644
> index 0000000..f314810
> --- /dev/null
> +++ b/drivers/rtc/rtc-pcf50633.c
> @@ -0,0 +1,302 @@
> +/* NXP PCF50633 RTC Driver
> + *
> + * (C) 2006-2008 by Openmoko, Inc.
> + * Author: Balaji Rao <balajirrao@openmoko.org>
> + * All rights reserved.
> + *
> + * Broken down from monstrous PCF50633 driver mainly by
> + * Harald Welte, Andy Green and Werner Almesberger
> + *
> + * 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.
> + *
> + * 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

 I believe the shorter form of the GPL could be good as well.

> + */
> +
> +#include <linux/rtc.h>
> +#include <linux/platform_device.h>
> +#include <linux/bcd.h>
> +
> +#include <linux/mfd/pcf50633/core.h>

> +#include <linux/mfd/pcf50633/rtc.h>

 this file should be included with the patch.


> +
> +enum pcf50633_time_indexes {
> +	PCF50633_TI_SEC,
> +	PCF50633_TI_MIN,
> +	PCF50633_TI_HOUR,
> +	PCF50633_TI_WKDAY,
> +	PCF50633_TI_DAY,
> +	PCF50633_TI_MONTH,
> +	PCF50633_TI_YEAR,
> +	PCF50633_TI_EXTENT /* always last */
> +};
> +
> +
> +struct pcf50633_time {
> +	u_int8_t time[PCF50633_TI_EXTENT];
> +};
> +
> +static void pcf2rtc_time(struct rtc_time *rtc, struct pcf50633_time *pcf)
> +{
> +	rtc->tm_sec = bcd2bin(pcf->time[PCF50633_TI_SEC]);
> +	rtc->tm_min = bcd2bin(pcf->time[PCF50633_TI_MIN]);
> +	rtc->tm_hour = bcd2bin(pcf->time[PCF50633_TI_HOUR]);
> +	rtc->tm_wday = bcd2bin(pcf->time[PCF50633_TI_WKDAY]);
> +	rtc->tm_mday = bcd2bin(pcf->time[PCF50633_TI_DAY]);
> +	rtc->tm_mon = bcd2bin(pcf->time[PCF50633_TI_MONTH]);
> +	rtc->tm_year = bcd2bin(pcf->time[PCF50633_TI_YEAR]) + 100;
> +}
> +
> +static void rtc2pcf_time(struct pcf50633_time *pcf, struct rtc_time *rtc)
> +{
> +	pcf->time[PCF50633_TI_SEC] = bin2bcd(rtc->tm_sec);
> +	pcf->time[PCF50633_TI_MIN] = bin2bcd(rtc->tm_min);
> +	pcf->time[PCF50633_TI_HOUR] = bin2bcd(rtc->tm_hour);
> +	pcf->time[PCF50633_TI_WKDAY] = bin2bcd(rtc->tm_wday);
> +	pcf->time[PCF50633_TI_DAY] = bin2bcd(rtc->tm_mday);
> +	pcf->time[PCF50633_TI_MONTH] = bin2bcd(rtc->tm_mon);
> +	pcf->time[PCF50633_TI_YEAR] = bin2bcd(rtc->tm_year - 100);
 
 you should add a check in the caller for tm_year < 100

> +}
> +
> +static int
> +pcf50633_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
> +{
> +	struct pcf50633 *pcf;
> +
> +	pcf = dev_get_drvdata(dev);

 this could be an one-liner (not mandatory).


> +	switch (cmd) {
> +	case RTC_AIE_OFF:
> +		pcf->rtc.alarm_enabled = 0;
> +		pcf50633_irq_mask(pcf, PCF50633_IRQ_ALARM);
> +		return 0;
> +	case RTC_AIE_ON:
> +		pcf->rtc.alarm_enabled = 1;
> +		pcf50633_irq_unmask(pcf, PCF50633_IRQ_ALARM);
> +		return 0;
> +	case RTC_PIE_OFF:
> +		pcf->rtc.second_enabled = 0;
> +		pcf50633_irq_mask(pcf, PCF50633_IRQ_SECOND);
> +		return 0;
> +	case RTC_PIE_ON:
> +		pcf->rtc.second_enabled = 1;
> +		pcf50633_irq_unmask(pcf, PCF50633_IRQ_SECOND);
> +		return 0;
> +	}

 we have recently improved the API for interrupts handling.
 the patch is now in -mm and you can check it here: 
 http://patchwork.ozlabs.org/patch/10039/

 that involves AIE and UIE.

 the API for PIE was always there and it's implemented by ops->irq_set_state
 and ops->irq_set_freq

 Is your PIE a real PIE or an UIE?


> +	return -ENOIOCTLCMD;
> +}
> +
> +static int pcf50633_rtc_read_time(struct device *dev, struct rtc_time *tm)
> +{
> +	struct pcf50633 *pcf;
> +	struct pcf50633_time pcf_tm;
> +	int ret;
> +
> +	pcf = dev_get_drvdata(dev);
> +
> +	ret = pcf50633_read_block(pcf, PCF50633_REG_RTCSC,
> +					    PCF50633_TI_EXTENT,
> +					    &pcf_tm.time[0]);
> +	if (ret != PCF50633_TI_EXTENT)
> +		dev_err(dev, "Failed to read time\n");

 so return -EIO or something to that effect.

> +	dev_dbg(dev, "PCF_TIME: %02x.%02x.%02x %02x:%02x:%02x\n",
> +		pcf_tm.time[PCF50633_TI_DAY],
> +		pcf_tm.time[PCF50633_TI_MONTH],
> +		pcf_tm.time[PCF50633_TI_YEAR],
> +		pcf_tm.time[PCF50633_TI_HOUR],
> +		pcf_tm.time[PCF50633_TI_MIN],
> +		pcf_tm.time[PCF50633_TI_SEC]);
> +
> +	pcf2rtc_time(tm, &pcf_tm);
> +
> +	dev_dbg(dev, "RTC_TIME: %u.%u.%u %u:%u:%u\n",
> +		tm->tm_mday, tm->tm_mon, tm->tm_year,
> +		tm->tm_hour, tm->tm_min, tm->tm_sec);
> +
> +	return 0;

 nope. always return rtc_valid_tm(tm);

> +}
> +
> +static int pcf50633_rtc_set_time(struct device *dev, struct rtc_time *tm)
> +{
> +	struct pcf50633 *pcf;
> +	struct pcf50633_time pcf_tm;
> +	int second_masked, alarm_masked, ret = 0;
> +
> +	pcf = dev_get_drvdata(dev);
> +
> +	dev_dbg(dev, "RTC_TIME: %u.%u.%u %u:%u:%u\n",
> +		tm->tm_mday, tm->tm_mon, tm->tm_year,
> +		tm->tm_hour, tm->tm_min, tm->tm_sec);
> +
> +	rtc2pcf_time(&pcf_tm, tm);
> +
> +	dev_dbg(dev, "PCF_TIME: %02x.%02x.%02x %02x:%02x:%02x\n",
> +		pcf_tm.time[PCF50633_TI_DAY],
> +		pcf_tm.time[PCF50633_TI_MONTH],
> +		pcf_tm.time[PCF50633_TI_YEAR],
> +		pcf_tm.time[PCF50633_TI_HOUR],
> +		pcf_tm.time[PCF50633_TI_MIN],
> +		pcf_tm.time[PCF50633_TI_SEC]);
> +
> +
> +	second_masked = pcf50633_irq_mask_get(pcf, PCF50633_IRQ_SECOND);
> +	alarm_masked = pcf50633_irq_mask_get(pcf, PCF50633_IRQ_ALARM);
> +
> +	if (!second_masked)
> +		pcf50633_irq_mask(pcf, PCF50633_IRQ_SECOND);
> +	if (!alarm_masked)
> +		pcf50633_irq_mask(pcf, PCF50633_IRQ_ALARM);
> +
> +	ret = pcf50633_write_block(pcf, PCF50633_REG_RTCSC,
> +					     PCF50633_TI_EXTENT,
> +					     &pcf_tm.time[0]);
> +	if (ret)
> +		dev_err(dev, "Failed to set time %d\n", ret);
> +
> +	if (!second_masked)
> +		pcf50633_irq_unmask(pcf, PCF50633_IRQ_SECOND);
> +	if (!alarm_masked)
> +		pcf50633_irq_unmask(pcf, PCF50633_IRQ_ALARM);
> +
> +	return ret;

 is this ret an appropriate error code?

> +}
> +
> +static int pcf50633_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> +	struct pcf50633 *pcf;
> +	struct pcf50633_time pcf_tm;
> +	int ret = 0;
> +
> +	pcf = dev_get_drvdata(dev);
> +
> +	alrm->enabled = pcf->rtc.alarm_enabled;
> +
> +	ret = pcf50633_read_block(pcf, PCF50633_REG_RTCSCA,
> +				PCF50633_TI_EXTENT, &pcf_tm.time[0]);
> +
> +	if (ret != PCF50633_TI_EXTENT)
> +		dev_err(dev, "Failed to read Alarm time %d\n", ret);
> +
> +	pcf2rtc_time(&alrm->time, &pcf_tm);
> +
> +	return ret;

 probably wrong, ret must be 0 on success.

> +}
> +
> +static int pcf50633_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> +	struct pcf50633 *pcf;
> +	struct pcf50633_time pcf_tm;
> +	int alarm_masked, ret = 0;
> +
> +	pcf = dev_get_drvdata(dev);
> +
> +	rtc2pcf_time(&pcf_tm, &alrm->time);
> +
> +	/* do like mktime does and ignore tm_wday */
> +	pcf_tm.time[PCF50633_TI_WKDAY] = 7;
> +
> +	alarm_masked = pcf50633_irq_mask_get(pcf, PCF50633_IRQ_ALARM);
> +
> +	/* disable alarm interrupt */
> +	if (!alarm_masked)
> +		pcf50633_irq_mask(pcf, PCF50633_IRQ_ALARM);
> +
> +	ret = pcf50633_write_block(pcf, PCF50633_REG_RTCSCA,
> +					PCF50633_TI_EXTENT, &pcf_tm.time[0]);
> +	if (ret)
> +		dev_err(dev, "Failed to write alarm time  %d\n", ret);
> +
> +	if (!alarm_masked)
> +		pcf50633_irq_unmask(pcf, PCF50633_IRQ_ALARM);
> +
> +	return ret;

 ditto?

> +}
> +static struct rtc_class_ops pcf50633_rtc_ops = {
> +	.ioctl		= pcf50633_rtc_ioctl,
> +	.read_time	= pcf50633_rtc_read_time,
> +	.set_time	= pcf50633_rtc_set_time,
> +	.read_alarm	= pcf50633_rtc_read_alarm,
> +	.set_alarm	= pcf50633_rtc_set_alarm,
> +};
> +
> +static void pcf50633_rtc_irq(struct pcf50633 *pcf, int irq, void *unused)
> +{
> +	switch (irq) {
> +	case PCF50633_IRQ_ALARM:
> +		rtc_update_irq(pcf->rtc.rtc_dev, 1, RTC_AF | RTC_IRQF);
> +		break;
> +	case PCF50633_IRQ_SECOND:
> +		rtc_update_irq(pcf->rtc.rtc_dev, 1, RTC_PF | RTC_IRQF);
> +		break;
> +	}
> +}
> +
> +static int pcf50633_rtc_probe(struct platform_device *pdev)
> +{
> +	struct rtc_device *rtc;
> +	struct pcf50633 *pcf;
> +
> +	rtc = rtc_device_register("pcf50633-rtc", &pdev->dev,
> +					&pcf50633_rtc_ops, THIS_MODULE);
> +	if (IS_ERR(rtc))
> +		return -ENODEV;

 nope. if IS_ERR means that the rtc pointer has a valid error
 code that you should return to the caller.

> +	pcf = platform_get_drvdata(pdev);

 uh? where did you set up the pointer?


> +	/* Set up IRQ handlers */
> +	pcf->irq_handler[PCF50633_IRQ_ALARM].handler = pcf50633_rtc_irq;
> +	pcf->irq_handler[PCF50633_IRQ_SECOND].handler = pcf50633_rtc_irq;
> +
> +	pcf->rtc.rtc_dev = rtc;

 ??

> +	return 0;
> +}
> +
> +static int pcf50633_rtc_remove(struct platform_device *pdev)
> +{
> +	struct pcf50633 *pcf;
> +
> +	pcf = platform_get_drvdata(pdev);
> +	rtc_device_unregister(pcf->rtc.rtc_dev);
> +
> +	return 0;
> +}
> +
> +
> +static struct platform_driver pcf50633_rtc_driver = {
> +	.driver = {
> +		.name = "pcf50633-rtc",
> +	},
> +	.probe = pcf50633_rtc_probe,
> +	.remove = __devexit_p(pcf50633_rtc_remove),

  you marked __devexit_p but forgot to mark the function
 itself.

> +};
> +
> +static int __init pcf50633_rtc_init(void)
> +{
> +	return platform_driver_register(&pcf50633_rtc_driver);

 can't you use platform_driver_probe ?

> +}
> +module_init(pcf50633_rtc_init);
> +
> +static void __exit pcf50633_rtc_exit(void)
> +{
> +	platform_driver_unregister(&pcf50633_rtc_driver);
> +}
> +module_exit(pcf50633_rtc_exit);
> +
> +
> +MODULE_DESCRIPTION("PCF50633 RTC driver");
> +MODULE_AUTHOR("Balaji Rao <balajirrao@openmoko.org>");
> +MODULE_LICENSE("GPL");
> +
> 


-- 

 Best regards,

 Alessandro Zummo,
  Tower Technologies - Torino, Italy

  http://www.towertech.it