diff options
| -rw-r--r-- | drivers/rtc/rtc-mcp795.c | 171 |
1 files changed, 170 insertions, 1 deletions
diff --git a/drivers/rtc/rtc-mcp795.c b/drivers/rtc/rtc-mcp795.c index 8107fc0a2be5..77f21331ae21 100644 --- a/drivers/rtc/rtc-mcp795.c +++ b/drivers/rtc/rtc-mcp795.c @@ -44,12 +44,22 @@ #define MCP795_REG_DAY 0x04 #define MCP795_REG_MONTH 0x06 #define MCP795_REG_CONTROL 0x08 +#define MCP795_REG_ALM0_SECONDS 0x0C +#define MCP795_REG_ALM0_DAY 0x0F #define MCP795_ST_BIT BIT(7) #define MCP795_24_BIT BIT(6) #define MCP795_LP_BIT BIT(5) #define MCP795_EXTOSC_BIT BIT(3) #define MCP795_OSCON_BIT BIT(5) +#define MCP795_ALM0_BIT BIT(4) +#define MCP795_ALM1_BIT BIT(5) +#define MCP795_ALM0IF_BIT BIT(3) +#define MCP795_ALM0C0_BIT BIT(4) +#define MCP795_ALM0C1_BIT BIT(5) +#define MCP795_ALM0C2_BIT BIT(6) + +#define SEC_PER_DAY (24 * 60 * 60) static int mcp795_rtcc_read(struct device *dev, u8 addr, u8 *buf, u8 count) { @@ -150,6 +160,30 @@ static int mcp795_start_oscillator(struct device *dev, bool *extosc) dev, MCP795_REG_SECONDS, MCP795_ST_BIT, MCP795_ST_BIT); } +/* Enable or disable Alarm 0 in RTC */ +static int mcp795_update_alarm(struct device *dev, bool enable) +{ + int ret; + + dev_dbg(dev, "%s alarm\n", enable ? "Enable" : "Disable"); + + if (enable) { + /* clear ALM0IF (Alarm 0 Interrupt Flag) bit */ + ret = mcp795_rtcc_set_bits(dev, MCP795_REG_ALM0_DAY, + MCP795_ALM0IF_BIT, 0); + if (ret) + return ret; + /* enable alarm 0 */ + ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL, + MCP795_ALM0_BIT, MCP795_ALM0_BIT); + } else { + /* disable alarm 0 and alarm 1 */ + ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL, + MCP795_ALM0_BIT | MCP795_ALM1_BIT, 0); + } + return ret; +} + static int mcp795_set_time(struct device *dev, struct rtc_time *tim) { int ret; @@ -231,9 +265,127 @@ static int mcp795_read_time(struct device *dev, struct rtc_time *tim) return rtc_valid_tm(tim); } +static int mcp795_set_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct rtc_time now_tm; + time64_t now; + time64_t later; + u8 tmp[6]; + int ret; + + /* Read current time from RTC hardware */ + ret = mcp795_read_time(dev, &now_tm); + if (ret) + return ret; + /* Get the number of seconds since 1970 */ + now = rtc_tm_to_time64(&now_tm); + later = rtc_tm_to_time64(&alm->time); + if (later <= now) + return -EINVAL; + /* make sure alarm fires within the next one year */ + if ((later - now) >= + (SEC_PER_DAY * (365 + is_leap_year(alm->time.tm_year)))) + return -EDOM; + /* disable alarm */ + ret = mcp795_update_alarm(dev, false); + if (ret) + return ret; + /* Read registers, so we can leave configuration bits untouched */ + ret = mcp795_rtcc_read(dev, MCP795_REG_ALM0_SECONDS, tmp, sizeof(tmp)); + if (ret) + return ret; + + alm->time.tm_year = -1; + alm->time.tm_isdst = -1; + alm->time.tm_yday = -1; + + tmp[0] = (tmp[0] & 0x80) | bin2bcd(alm->time.tm_sec); + tmp[1] = (tmp[1] & 0x80) | bin2bcd(alm->time.tm_min); + tmp[2] = (tmp[2] & 0xE0) | bin2bcd(alm->time.tm_hour); + tmp[3] = (tmp[3] & 0x80) | bin2bcd(alm->time.tm_wday + 1); + /* set alarm match: seconds, minutes, hour, day, date and month */ + tmp[3] |= (MCP795_ALM0C2_BIT | MCP795_ALM0C1_BIT | MCP795_ALM0C0_BIT); + tmp[4] = (tmp[4] & 0xC0) | bin2bcd(alm->time.tm_mday); + tmp[5] = (tmp[5] & 0xE0) | bin2bcd(alm->time.tm_mon + 1); + + ret = mcp795_rtcc_write(dev, MCP795_REG_ALM0_SECONDS, tmp, sizeof(tmp)); + if (ret) + return ret; + + /* enable alarm if requested */ + if (alm->enabled) { + ret = mcp795_update_alarm(dev, true); + if (ret) + return ret; + dev_dbg(dev, "Alarm IRQ armed\n"); + } + dev_dbg(dev, "Set alarm: %02d-%02d(%d) %02d:%02d:%02d\n", + alm->time.tm_mon, alm->time.tm_mday, alm->time.tm_wday, + alm->time.tm_hour, alm->time.tm_min, alm->time.tm_sec); + return 0; +} + +static int mcp795_read_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + u8 data[6]; + int ret; + + ret = mcp795_rtcc_read( + dev, MCP795_REG_ALM0_SECONDS, data, sizeof(data)); + if (ret) + return ret; + + alm->time.tm_sec = bcd2bin(data[0] & 0x7F); + alm->time.tm_min = bcd2bin(data[1] & 0x7F); + alm->time.tm_hour = bcd2bin(data[2] & 0x1F); + alm->time.tm_wday = bcd2bin(data[3] & 0x07) - 1; + alm->time.tm_mday = bcd2bin(data[4] & 0x3F); + alm->time.tm_mon = bcd2bin(data[5] & 0x1F) - 1; + alm->time.tm_year = -1; + alm->time.tm_isdst = -1; + alm->time.tm_yday = -1; + + dev_dbg(dev, "Read alarm: %02d-%02d(%d) %02d:%02d:%02d\n", + alm->time.tm_mon, alm->time.tm_mday, alm->time.tm_wday, + alm->time.tm_hour, alm->time.tm_min, alm->time.tm_sec); + return 0; +} + +static int mcp795_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + return mcp795_update_alarm(dev, !!enabled); +} + +static irqreturn_t mcp795_irq(int irq, void *data) +{ + struct spi_device *spi = data; + struct rtc_device *rtc = spi_get_drvdata(spi); + struct mutex *lock = &rtc->ops_lock; + int ret; + + mutex_lock(lock); + + /* Disable alarm. + * There is no need to clear ALM0IF (Alarm 0 Interrupt Flag) bit, + * because it is done every time when alarm is enabled. + */ + ret = mcp795_update_alarm(&spi->dev, false); + if (ret) + dev_err(&spi->dev, + "Failed to disable alarm in IRQ (ret=%d)\n", ret); + rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF); + + mutex_unlock(lock); + + return IRQ_HANDLED; +} + static const struct rtc_class_ops mcp795_rtc_ops = { .read_time = mcp795_read_time, - .set_time = mcp795_set_time + .set_time = mcp795_set_time, + .read_alarm = mcp795_read_alarm, + .set_alarm = mcp795_set_alarm, + .alarm_irq_enable = mcp795_alarm_irq_enable }; static int mcp795_probe(struct spi_device *spi) @@ -261,6 +413,23 @@ static int mcp795_probe(struct spi_device *spi) spi_set_drvdata(spi, rtc); + if (spi->irq > 0) { + dev_dbg(&spi->dev, "Alarm support enabled\n"); + + /* Clear any pending alarm (ALM0IF bit) before requesting + * the interrupt. + */ + mcp795_rtcc_set_bits(&spi->dev, MCP795_REG_ALM0_DAY, + MCP795_ALM0IF_BIT, 0); + ret = devm_request_threaded_irq(&spi->dev, spi->irq, NULL, + mcp795_irq, IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + dev_name(&rtc->dev), spi); + if (ret) + dev_err(&spi->dev, "Failed to request IRQ: %d: %d\n", + spi->irq, ret); + else + device_init_wakeup(&spi->dev, true); + } return 0; } |