Den fre. 19. jun. 2020 kl. 06.12 skrev Liam Beguin <liambeguin@xxxxxxxxx>:
>
> From: Liam Beguin <lvb@xxxxxxxxxx>
>
> Add alarm support for the pcf2127 RTC chip family.
> Tested on pca2129.
>
> Signed-off-by: Liam Beguin <lvb@xxxxxxxxxx>
> ---
> Changes since v1:
> - Add calls to pcf2127_wdt_active_ping after accessing CTRL2
> - Cleanup calls to regmap_{read,write,update_bits}
> - Cleanup debug trace
> - Add interrupt handler, untested because of hardware limitations
> - Add wakeup-source devicetree option
>
> Changes since v2:
> - Avoid forward declaration of pcf2127_wdt_active_ping
> - Remove dev_err strings
> - Remove dev_dbg traces since they are now part of the core
> - Remove redundant if in pcf2127_rtc_alarm_irq_enable
> - Remove duplicate watchdog ping in pcf2127_rtc_irq
> - Avoid unnecessary read in pcf2127_rtc_irq with regmap_write
> - Add extra rtc_class_ops struct with alarm functions
>
> drivers/rtc/rtc-pcf2127.c | 136 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 136 insertions(+)
>
> diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
> index 4accee09bfad..df09d3c6c5c3 100644
> --- a/drivers/rtc/rtc-pcf2127.c
> +++ b/drivers/rtc/rtc-pcf2127.c
> @@ -20,6 +20,7 @@
> #include <linux/slab.h>
> #include <linux/module.h>
> #include <linux/of.h>
> +#include <linux/of_irq.h>
> #include <linux/regmap.h>
> #include <linux/watchdog.h>
>
> @@ -28,7 +29,9 @@
> #define PCF2127_BIT_CTRL1_TSF1 BIT(4)
> /* Control register 2 */
> #define PCF2127_REG_CTRL2 0x01
> +#define PCF2127_BIT_CTRL2_AIE BIT(1)
> #define PCF2127_BIT_CTRL2_TSIE BIT(2)
> +#define PCF2127_BIT_CTRL2_AF BIT(4)
> #define PCF2127_BIT_CTRL2_TSF2 BIT(5)
> /* Control register 3 */
> #define PCF2127_REG_CTRL3 0x02
> @@ -46,6 +49,12 @@
> #define PCF2127_REG_DW 0x07
> #define PCF2127_REG_MO 0x08
> #define PCF2127_REG_YR 0x09
> +/* Alarm registers */
> +#define PCF2127_REG_ALARM_SC 0x0A
> +#define PCF2127_REG_ALARM_MN 0x0B
> +#define PCF2127_REG_ALARM_HR 0x0C
> +#define PCF2127_REG_ALARM_DM 0x0D
> +#define PCF2127_REG_ALARM_DW 0x0E
> /* Watchdog registers */
> #define PCF2127_REG_WD_CTL 0x10
> #define PCF2127_BIT_WD_CTL_TF0 BIT(0)
> @@ -324,6 +333,116 @@ static const struct watchdog_ops pcf2127_watchdog_ops = {
> .set_timeout = pcf2127_wdt_set_timeout,
> };
>
> +/* Alarm */
> +static int pcf2127_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> + struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
> + unsigned int buf[5], ctrl2;
> + int ret;
> +
> + ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL2, &ctrl2);
> + if (ret)
> + return ret;
> +
> + ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
> + if (ret)
> + return ret;
> +
> + ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_ALARM_SC, buf,
> + sizeof(buf));
> + if (ret)
> + return ret;
> +
> + alrm->enabled = ctrl2 & PCF2127_BIT_CTRL2_AIE;
> + alrm->pending = ctrl2 & PCF2127_BIT_CTRL2_AF;
> +
> + alrm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
> + alrm->time.tm_min = bcd2bin(buf[1] & 0x7F);
> + alrm->time.tm_hour = bcd2bin(buf[2] & 0x3F);
> + alrm->time.tm_mday = bcd2bin(buf[3] & 0x3F);
> + alrm->time.tm_wday = buf[4] & 0x07;
> +
> + return 0;
> +}
> +
> +static int pcf2127_rtc_alarm_irq_enable(struct device *dev, u32 enable)
> +{
> + struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
> + PCF2127_BIT_CTRL2_AIE,
> + enable ? PCF2127_BIT_CTRL2_AIE : 0);
> + if (ret)
> + return ret;
> +
> + return pcf2127_wdt_active_ping(&pcf2127->wdd);
> +}
> +
> +static int pcf2127_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> + struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
> + uint8_t buf[5];
> + int ret;
> +
> + ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
> + PCF2127_BIT_CTRL2_AF, 0);
> + if (ret)
> + return ret;
> +
> + ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
> + if (ret)
> + return ret;
> +
> + buf[0] = bin2bcd(alrm->time.tm_sec);
> + buf[1] = bin2bcd(alrm->time.tm_min);
> + buf[2] = bin2bcd(alrm->time.tm_hour);
> + buf[3] = bin2bcd(alrm->time.tm_mday);
> + buf[4] = (alrm->time.tm_wday & 0x07);
> +
> + ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_ALARM_SC, buf,
> + sizeof(buf));
> + if (ret)
> + return ret;
> +
> + return pcf2127_rtc_alarm_irq_enable(dev, alrm->enabled);
> +}
> +
> +static irqreturn_t pcf2127_rtc_irq(int irq, void *dev)
> +{
> + struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
> + unsigned int ctrl2 = 0;
> + int ret = 0;
> +
> + ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL2, &ctrl2);
> + if (ret)
> + goto irq_err;
> +
> + if (ctrl2 & PCF2127_BIT_CTRL2_AF) {
> + regmap_write(pcf2127->regmap, PCF2127_REG_CTRL2,
> + ctrl2 & ~PCF2127_BIT_CTRL2_AF);
> +
> + rtc_update_irq(pcf2127->rtc, 1, RTC_IRQF | RTC_AF);
> + }
> +
> + ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
> + if (ret)
> + goto irq_err;
> +
> + return IRQ_HANDLED;
> +irq_err:
> + return IRQ_NONE;
It's not really needed to use "goto irq_err;" syntax as there is no
common error cleanup
path and can simply be replaced by "return IRQ_NONE;".
Overall this feature looks good to me.
Reviewed-by: Bruno Thomsen <bruno.thomsen@xxxxxxxxx>
/Bruno
> +}
> +
> +static const struct rtc_class_ops pcf2127_rtc_alrm_ops = {
> + .ioctl = pcf2127_rtc_ioctl,
> + .read_time = pcf2127_rtc_read_time,
> + .set_time = pcf2127_rtc_set_time,
> + .read_alarm = pcf2127_rtc_read_alarm,
> + .set_alarm = pcf2127_rtc_set_alarm,
> + .alarm_irq_enable = pcf2127_rtc_alarm_irq_enable,
> +};
> +
> /* sysfs interface */
>
> static ssize_t timestamp0_store(struct device *dev,
> @@ -419,6 +538,7 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
> const char *name, bool has_nvmem)
> {
> struct pcf2127 *pcf2127;
> + int alarm_irq = 0;
> u32 wdd_timeout;
> int ret = 0;
>
> @@ -441,6 +561,22 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
> pcf2127->rtc->range_max = RTC_TIMESTAMP_END_2099;
> pcf2127->rtc->set_start_time = true; /* Sets actual start to 1970 */
>
> + alarm_irq = of_irq_get_byname(dev->of_node, "alarm");
> + if (alarm_irq >= 0) {
> + ret = devm_request_irq(dev, alarm_irq, pcf2127_rtc_irq,
> + IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> + dev_name(dev), dev);
> + if (ret) {
> + dev_err(dev, "failed to request alarm irq\n");
> + return ret;
> + }
> + }
> +
> + if (alarm_irq >= 0 || device_property_read_bool(dev, "wakeup-source")) {
> + device_init_wakeup(dev, true);
> + pcf2127->rtc->ops = &pcf2127_rtc_alrm_ops;
> + }
> +
> pcf2127->wdd.parent = dev;
> pcf2127->wdd.info = &pcf2127_wdt_info;
> pcf2127->wdd.ops = &pcf2127_watchdog_ops;
> --
> 2.27.0
>
