// SPDX-License-Identifier: GPL-2.0-only/* * rtc-ds1305.c -- driver for DS1305 and DS1306 SPI RTC chips * * Copyright (C) 2008 David Brownell */#include <linux/kernel.h>#include <linux/init.h>#include <linux/bcd.h>#include <linux/slab.h>#include <linux/rtc.h>#include <linux/workqueue.h> #include <linux/spi/spi.h>#include <linux/spi/ds1305.h>#include <linux/module.h> /* * Registers ... mask DS1305_WRITE into register address to write, * otherwise you're reading it. All non-bitmask values are BCD. */#define DS1305_WRITE 0x80 /* RTC date/time ... the main special cases are that we: * - Need fancy "hours" encoding in 12hour mode * - Don't rely on the "day-of-week" field (or tm_wday) * - Are a 21st-century clock (2000 <= year < 2100) */#define DS1305_RTC_LEN 7 /* bytes for RTC regs */ #define DS1305_SEC 0x00 /* register addresses */#define DS1305_MIN 0x01#define DS1305_HOUR 0x02# define DS1305_HR_12 0x40 /* set == 12 hr mode */# define DS1305_HR_PM 0x20 /* set == PM (12hr mode) */#define DS1305_WDAY 0x03#define DS1305_MDAY 0x04#define DS1305_MON 0x05#define DS1305_YEAR 0x06 /* The two alarms have only sec/min/hour/wday fields (ALM_LEN). * DS1305_ALM_DISABLE disables a match field (some combos are bad). * * NOTE that since we don't use WDAY, we limit ourselves to alarms * only one day into the future (vs potentially up to a week). * * NOTE ALSO that while we could generate once-a-second IRQs (UIE), we * don't currently support them. We'd either need to do it only when * no alarm is pending (not the standard model), or to use the second * alarm (implying that this is a DS1305 not DS1306, *and* that either * it's wired up a second IRQ we know, or that INTCN is set) */#define DS1305_ALM_LEN 4 /* bytes for ALM regs */#define DS1305_ALM_DISABLE 0x80 #define DS1305_ALM0(r) (0x07 + (r)) /* register addresses */#define DS1305_ALM1(r) (0x0b + (r)) /* three control registers */#define DS1305_CONTROL_LEN 3 /* bytes of control regs */ #define DS1305_CONTROL 0x0f /* register addresses */# define DS1305_nEOSC 0x80 /* low enables oscillator */# define DS1305_WP 0x40 /* write protect */# define DS1305_INTCN 0x04 /* clear == only int0 used */# define DS1306_1HZ 0x04 /* enable 1Hz output */# define DS1305_AEI1 0x02 /* enable ALM1 IRQ */# define DS1305_AEI0 0x01 /* enable ALM0 IRQ */#define DS1305_STATUS 0x10/* status has just AEIx bits, mirrored as IRQFx */#define DS1305_TRICKLE 0x11/* trickle bits are defined in <linux/spi/ds1305.h> */ /* a bunch of NVRAM */#define DS1305_NVRAM_LEN 96 /* bytes of NVRAM */ #define DS1305_NVRAM 0x20 /* register addresses */ struct ds1305 { struct spi_device *spi; struct rtc_device *rtc; struct work_struct work; unsigned long flags;#define FLAG_EXITING 0 bool hr12; u8 ctrl[DS1305_CONTROL_LEN];}; /*----------------------------------------------------------------------*/ /* * Utilities ... tolerate 12-hour AM/PM notation in case of non-Linux * software (like a bootloader) which may require it. */ static unsigned bcd2hour(u8 bcd){ if (bcd & DS1305_HR_12) { unsigned hour = 0; bcd &= ~DS1305_HR_12; if (bcd & DS1305_HR_PM) { hour = 12; bcd &= ~DS1305_HR_PM; } hour += bcd2bin(bcd); return hour - 1; } return bcd2bin(bcd);} static u8 hour2bcd(bool hr12, int hour){ if (hr12) { hour++; if (hour <= 12) return DS1305_HR_12 | bin2bcd(hour); hour -= 12; return DS1305_HR_12 | DS1305_HR_PM | bin2bcd(hour); } return bin2bcd(hour);} /*----------------------------------------------------------------------*/ /* * Interface to RTC framework */ static int ds1305_alarm_irq_enable(struct device *dev, unsigned int enabled){ struct ds1305 *ds1305 = dev_get_drvdata(dev); u8 buf[2]; long err = -EINVAL; buf[0] = DS1305_WRITE | DS1305_CONTROL; buf[1] = ds1305->ctrl[0]; if (enabled) { if (ds1305->ctrl[0] & DS1305_AEI0) goto done; buf[1] |= DS1305_AEI0; } else { if (!(buf[1] & DS1305_AEI0)) goto done; buf[1] &= ~DS1305_AEI0; } err = spi_write_then_read(ds1305->spi, buf, sizeof(buf), NULL, 0); if (err >= 0) ds1305->ctrl[0] = buf[1];done: return err; } /* * Get/set of date and time is pretty normal. */ static int ds1305_get_time(struct device *dev, struct rtc_time *time){ struct ds1305 *ds1305 = dev_get_drvdata(dev); u8 addr = DS1305_SEC; u8 buf[DS1305_RTC_LEN]; int status; /* Use write-then-read to get all the date/time registers * since dma from stack is nonportable */ status = spi_write_then_read(ds1305->spi, &addr, sizeof(addr), buf, sizeof(buf)); if (status < 0) return status; dev_vdbg(dev, "%s: %3ph, %4ph\n", "read", &buf[0], &buf[3]); /* Decode the registers */ time->tm_sec = bcd2bin(buf[DS1305_SEC]); time->tm_min = bcd2bin(buf[DS1305_MIN]); time->tm_hour = bcd2hour(buf[DS1305_HOUR]); time->tm_wday = buf[DS1305_WDAY] - 1; time->tm_mday = bcd2bin(buf[DS1305_MDAY]); time->tm_mon = bcd2bin(buf[DS1305_MON]) - 1; time->tm_year = bcd2bin(buf[DS1305_YEAR]) + 100; dev_vdbg(dev, "%s secs=%d, mins=%d, " "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", "read", time->tm_sec, time->tm_min, time->tm_hour, time->tm_mday, time->tm_mon, time->tm_year, time->tm_wday); return 0;} static int ds1305_set_time(struct device *dev, struct rtc_time *time){ struct ds1305 *ds1305 = dev_get_drvdata(dev); u8 buf[1 + DS1305_RTC_LEN]; u8 *bp = buf; dev_vdbg(dev, "%s secs=%d, mins=%d, " "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", "write", time->tm_sec, time->tm_min, time->tm_hour, time->tm_mday, time->tm_mon, time->tm_year, time->tm_wday); /* Write registers starting at the first time/date address. */ *bp++ = DS1305_WRITE | DS1305_SEC; *bp++ = bin2bcd(time->tm_sec); *bp++ = bin2bcd(time->tm_min); *bp++ = hour2bcd(ds1305->hr12, time->tm_hour); *bp++ = (time->tm_wday < 7) ? (time->tm_wday + 1) : 1; *bp++ = bin2bcd(time->tm_mday); *bp++ = bin2bcd(time->tm_mon + 1); *bp++ = bin2bcd(time->tm_year - 100); dev_dbg(dev, "%s: %3ph, %4ph\n", "write", &buf[1], &buf[4]); /* use write-then-read since dma from stack is nonportable */ return spi_write_then_read(ds1305->spi, buf, sizeof(buf), NULL, 0);} /* * Get/set of alarm is a bit funky: * * - First there's the inherent raciness of getting the (partitioned) * status of an alarm that could trigger while we're reading parts * of that status. * * - Second there's its limited range (we could increase it a bit by * relying on WDAY), which means it will easily roll over. * * - Third there's the choice of two alarms and alarm signals. * Here we use ALM0 and expect that nINT0 (open drain) is used; * that's the only real option for DS1306 runtime alarms, and is * natural on DS1305. * * - Fourth, there's also ALM1, and a second interrupt signal: * + On DS1305 ALM1 uses nINT1 (when INTCN=1) else nINT0; * + On DS1306 ALM1 only uses INT1 (an active high pulse) * and it won't work when VCC1 is active. * * So to be most general, we should probably set both alarms to the * same value, letting ALM1 be the wakeup event source on DS1306 * and handling several wiring options on DS1305. * * - Fifth, we support the polled mode (as well as possible; why not?) * even when no interrupt line is wired to an IRQ. */ /* * Context: caller holds rtc->ops_lock (to protect ds1305->ctrl) */static int ds1305_get_alarm(struct device *dev, struct rtc_wkalrm *alm){ struct ds1305 *ds1305 = dev_get_drvdata(dev); struct spi_device *spi = ds1305->spi; u8 addr; int status; u8 buf[DS1305_ALM_LEN]; /* Refresh control register cache BEFORE reading ALM0 registers, * since reading alarm registers acks any pending IRQ. That * makes returning "pending" status a bit of a lie, but that bit * of EFI status is at best fragile anyway (given IRQ handlers). */ addr = DS1305_CONTROL; status = spi_write_then_read(spi, &addr, sizeof(addr), ds1305->ctrl, sizeof(ds1305->ctrl)); if (status < 0) return status; alm->enabled = !!(ds1305->ctrl[0] & DS1305_AEI0); alm->pending = !!(ds1305->ctrl[1] & DS1305_AEI0); /* get and check ALM0 registers */ addr = DS1305_ALM0(DS1305_SEC); status = spi_write_then_read(spi, &addr, sizeof(addr), buf, sizeof(buf)); if (status < 0) return status; dev_vdbg(dev, "%s: %02x %02x %02x %02x\n", "alm0 read", buf[DS1305_SEC], buf[DS1305_MIN], buf[DS1305_HOUR], buf[DS1305_WDAY]); if ((DS1305_ALM_DISABLE & buf[DS1305_SEC]) || (DS1305_ALM_DISABLE & buf[DS1305_MIN]) || (DS1305_ALM_DISABLE & buf[DS1305_HOUR])) return -EIO; /* Stuff these values into alm->time and let RTC framework code * fill in the rest ... and also handle rollover to tomorrow when * that's needed. */ alm->time.tm_sec = bcd2bin(buf[DS1305_SEC]); alm->time.tm_min = bcd2bin(buf[DS1305_MIN]); alm->time.tm_hour = bcd2hour(buf[DS1305_HOUR]); return 0;} /* * Context: caller holds rtc->ops_lock (to protect ds1305->ctrl) */static int ds1305_set_alarm(struct device *dev, struct rtc_wkalrm *alm){ struct ds1305 *ds1305 = dev_get_drvdata(dev); struct spi_device *spi = ds1305->spi; unsigned long now, later; struct rtc_time tm; int status; u8 buf[1 + DS1305_ALM_LEN]; /* convert desired alarm to time_t */ later = rtc_tm_to_time64(&alm->time); /* Read current time as time_t */ status = ds1305_get_time(dev, &tm); if (status < 0) return status; now = rtc_tm_to_time64(&tm); /* make sure alarm fires within the next 24 hours */ if (later <= now) return -EINVAL; if ((later - now) > ds1305->rtc->alarm_offset_max) return -ERANGE; /* disable alarm if needed */ if (ds1305->ctrl[0] & DS1305_AEI0) { ds1305->ctrl[0] &= ~DS1305_AEI0; buf[0] = DS1305_WRITE | DS1305_CONTROL; buf[1] = ds1305->ctrl[0]; status = spi_write_then_read(ds1305->spi, buf, 2, NULL, 0); if (status < 0) return status; } /* write alarm */ buf[0] = DS1305_WRITE | DS1305_ALM0(DS1305_SEC); buf[1 + DS1305_SEC] = bin2bcd(alm->time.tm_sec); buf[1 + DS1305_MIN] = bin2bcd(alm->time.tm_min); buf[1 + DS1305_HOUR] = hour2bcd(ds1305->hr12, alm->time.tm_hour); buf[1 + DS1305_WDAY] = DS1305_ALM_DISABLE; dev_dbg(dev, "%s: %02x %02x %02x %02x\n", "alm0 write", buf[1 + DS1305_SEC], buf[1 + DS1305_MIN], buf[1 + DS1305_HOUR], buf[1 + DS1305_WDAY]); status = spi_write_then_read(spi, buf, sizeof(buf), NULL, 0); if (status < 0) return status; /* enable alarm if requested */ if (alm->enabled) { ds1305->ctrl[0] |= DS1305_AEI0; buf[0] = DS1305_WRITE | DS1305_CONTROL; buf[1] = ds1305->ctrl[0]; status = spi_write_then_read(ds1305->spi, buf, 2, NULL, 0); } return status;} #ifdef CONFIG_PROC_FS static int ds1305_proc(struct device *dev, struct seq_file *seq){ struct ds1305 *ds1305 = dev_get_drvdata(dev); char *diodes = "no"; char *resistors = ""; /* ctrl[2] is treated as read-only; no locking needed */ if ((ds1305->ctrl[2] & 0xf0) == DS1305_TRICKLE_MAGIC) { switch (ds1305->ctrl[2] & 0x0c) { case DS1305_TRICKLE_DS2: diodes = "2 diodes, "; break; case DS1305_TRICKLE_DS1: diodes = "1 diode, "; break; default: goto done; } switch (ds1305->ctrl[2] & 0x03) { case DS1305_TRICKLE_2K: resistors = "2k Ohm"; break; case DS1305_TRICKLE_4K: resistors = "4k Ohm"; break; case DS1305_TRICKLE_8K: resistors = "8k Ohm"; break; default: diodes = "no"; break; } } done: seq_printf(seq, "trickle_charge\t: %s%s\n", diodes, resistors); return 0;} #else#define ds1305_proc NULL#endif static const struct rtc_class_ops ds1305_ops = { .read_time = ds1305_get_time, .set_time = ds1305_set_time, .read_alarm = ds1305_get_alarm, .set_alarm = ds1305_set_alarm, .proc = ds1305_proc, .alarm_irq_enable = ds1305_alarm_irq_enable,}; static void ds1305_work(struct work_struct *work){ struct ds1305 *ds1305 = container_of(work, struct ds1305, work); struct spi_device *spi = ds1305->spi; u8 buf[3]; int status; /* lock to protect ds1305->ctrl */ rtc_lock(ds1305->rtc); /* Disable the IRQ, and clear its status ... for now, we "know" * that if more than one alarm is active, they're in sync. * Note that reading ALM data registers also clears IRQ status. */ ds1305->ctrl[0] &= ~(DS1305_AEI1 | DS1305_AEI0); ds1305->ctrl[1] = 0; buf[0] = DS1305_WRITE | DS1305_CONTROL; buf[1] = ds1305->ctrl[0]; buf[2] = 0; status = spi_write_then_read(spi, buf, sizeof(buf), NULL, 0); if (status < 0) dev_dbg(&spi->dev, "clear irq --> %d\n", status); rtc_unlock(ds1305->rtc); if (!test_bit(FLAG_EXITING, &ds1305->flags)) enable_irq(spi->irq); rtc_update_irq(ds1305->rtc, 1, RTC_AF | RTC_IRQF);} /* * This "real" IRQ handler hands off to a workqueue mostly to allow * mutex locking for ds1305->ctrl ... unlike I2C, we could issue async * I/O requests in IRQ context (to clear the IRQ status). */static irqreturn_t ds1305_irq(int irq, void *p){ struct ds1305 *ds1305 = p; disable_irq(irq); schedule_work(&ds1305->work); return IRQ_HANDLED;} /*----------------------------------------------------------------------*/ /* * Interface for NVRAM */ static void msg_init(struct spi_message *m, struct spi_transfer *x, u8 *addr, size_t count, char *tx, char *rx){ spi_message_init(m); memset(x, 0, 2 * sizeof(*x)); x->tx_buf = addr; x->len = 1; spi_message_add_tail(x, m); x++; Lines 1–500 of 747. 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// SPDX-License-Identifier: GPL-2.0-only /* * rtc-ds1305.c -- driver for DS1305 and DS1306 SPI RTC chips * * Copyright (C) 2008 David Brownell */ #include <linux/kernel.h> #include <linux/init.h> #include <linux/bcd.h> #include <linux/slab.h> #include <linux/rtc.h> #include <linux/workqueue.h> #include <linux/spi/spi.h> #include <linux/spi/ds1305.h> #include <linux/module.h> /* * Registers ... mask DS1305_WRITE into register address to write, * otherwise you're reading it. All non-bitmask values are BCD. */ #define DS1305_WRITE 0x80 /* RTC date/time ... the main special cases are that we: * - Need fancy "hours" encoding in 12hour mode * - Don't rely on the "day-of-week" field (or tm_wday) * - Are a 21st-century clock (2000 <= year < 2100) */ #define DS1305_RTC_LEN 7 /* bytes for RTC regs */ #define DS1305_SEC 0x00 /* register addresses */ #define DS1305_MIN 0x01 #define DS1305_HOUR 0x02 # define DS1305_HR_12 0x40 /* set == 12 hr mode */ # define DS1305_HR_PM 0x20 /* set == PM (12hr mode) */ #define DS1305_WDAY 0x03 #define DS1305_MDAY 0x04 #define DS1305_MON 0x05 #define DS1305_YEAR 0x06 /* The two alarms have only sec/min/hour/wday fields (ALM_LEN). * DS1305_ALM_DISABLE disables a match field (some combos are bad). * * NOTE that since we don't use WDAY, we limit ourselves to alarms * only one day into the future (vs potentially up to a week). * * NOTE ALSO that while we could generate once-a-second IRQs (UIE), we * don't currently support them. We'd either need to do it only when * no alarm is pending (not the standard model), or to use the second * alarm (implying that this is a DS1305 not DS1306, *and* that either * it's wired up a second IRQ we know, or that INTCN is set) */ #define DS1305_ALM_LEN 4 /* bytes for ALM regs */ #define DS1305_ALM_DISABLE 0x80 #define DS1305_ALM0(r) (0x07 + (r)) /* register addresses */ #define DS1305_ALM1(r) (0x0b + (r)) /* three control registers */ #define DS1305_CONTROL_LEN 3 /* bytes of control regs */ #define DS1305_CONTROL 0x0f /* register addresses */ # define DS1305_nEOSC 0x80 /* low enables oscillator */ # define DS1305_WP 0x40 /* write protect */ # define DS1305_INTCN 0x04 /* clear == only int0 used */ # define DS1306_1HZ 0x04 /* enable 1Hz output */ # define DS1305_AEI1 0x02 /* enable ALM1 IRQ */ # define DS1305_AEI0 0x01 /* enable ALM0 IRQ */ #define DS1305_STATUS 0x10 /* status has just AEIx bits, mirrored as IRQFx */ #define DS1305_TRICKLE 0x11 /* trickle bits are defined in <linux/spi/ds1305.h> */ /* a bunch of NVRAM */ #define DS1305_NVRAM_LEN 96 /* bytes of NVRAM */ #define DS1305_NVRAM 0x20 /* register addresses */ struct ds1305 { struct spi_device *spi; struct rtc_device *rtc; struct work_struct work; unsigned long flags; #define FLAG_EXITING 0 bool hr12; u8 ctrl[DS1305_CONTROL_LEN]; }; /*----------------------------------------------------------------------*/ /* * Utilities ... tolerate 12-hour AM/PM notation in case of non-Linux * software (like a bootloader) which may require it. */ static unsigned bcd2hour(u8 bcd) { if (bcd & DS1305_HR_12) { unsigned hour = 0; bcd &= ~DS1305_HR_12; if (bcd & DS1305_HR_PM) { hour = 12; bcd &= ~DS1305_HR_PM; } hour += bcd2bin(bcd); return hour - 1; } return bcd2bin(bcd); } static u8 hour2bcd(bool hr12, int hour) { if (hr12) { hour++; if (hour <= 12) return DS1305_HR_12 | bin2bcd(hour); hour -= 12; return DS1305_HR_12 | DS1305_HR_PM | bin2bcd(hour); } return bin2bcd(hour); } /*----------------------------------------------------------------------*/ /* * Interface to RTC framework */ static int ds1305_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct ds1305 *ds1305 = dev_get_drvdata(dev); u8 buf[2]; long err = -EINVAL; buf[0] = DS1305_WRITE | DS1305_CONTROL; buf[1] = ds1305->ctrl[0]; if (enabled) { if (ds1305->ctrl[0] & DS1305_AEI0) goto done; buf[1] |= DS1305_AEI0; } else { if (!(buf[1] & DS1305_AEI0)) goto done; buf[1] &= ~DS1305_AEI0; } err = spi_write_then_read(ds1305->spi, buf, sizeof(buf), NULL, 0); if (err >= 0) ds1305->ctrl[0] = buf[1]; done: return err; } /* * Get/set of date and time is pretty normal. */ static int ds1305_get_time(struct device *dev, struct rtc_time *time) { struct ds1305 *ds1305 = dev_get_drvdata(dev); u8 addr = DS1305_SEC; u8 buf[DS1305_RTC_LEN]; int status; /* Use write-then-read to get all the date/time registers * since dma from stack is nonportable */ status = spi_write_then_read(ds1305->spi, &addr, sizeof(addr), buf, sizeof(buf)); if (status < 0) return status; dev_vdbg(dev, "%s: %3ph, %4ph\n", "read", &buf[0], &buf[3]); /* Decode the registers */ time->tm_sec = bcd2bin(buf[DS1305_SEC]); time->tm_min = bcd2bin(buf[DS1305_MIN]); time->tm_hour = bcd2hour(buf[DS1305_HOUR]); time->tm_wday = buf[DS1305_WDAY] - 1; time->tm_mday = bcd2bin(buf[DS1305_MDAY]); time->tm_mon = bcd2bin(buf[DS1305_MON]) - 1; time->tm_year = bcd2bin(buf[DS1305_YEAR]) + 100; dev_vdbg(dev, "%s secs=%d, mins=%d, " "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", "read", time->tm_sec, time->tm_min, time->tm_hour, time->tm_mday, time->tm_mon, time->tm_year, time->tm_wday); return 0; } static int ds1305_set_time(struct device *dev, struct rtc_time *time) { struct ds1305 *ds1305 = dev_get_drvdata(dev); u8 buf[1 + DS1305_RTC_LEN]; u8 *bp = buf; dev_vdbg(dev, "%s secs=%d, mins=%d, " "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", "write", time->tm_sec, time->tm_min, time->tm_hour, time->tm_mday, time->tm_mon, time->tm_year, time->tm_wday); /* Write registers starting at the first time/date address. */ *bp++ = DS1305_WRITE | DS1305_SEC; *bp++ = bin2bcd(time->tm_sec); *bp++ = bin2bcd(time->tm_min); *bp++ = hour2bcd(ds1305->hr12, time->tm_hour); *bp++ = (time->tm_wday < 7) ? (time->tm_wday + 1) : 1; *bp++ = bin2bcd(time->tm_mday); *bp++ = bin2bcd(time->tm_mon + 1); *bp++ = bin2bcd(time->tm_year - 100); dev_dbg(dev, "%s: %3ph, %4ph\n", "write", &buf[1], &buf[4]); /* use write-then-read since dma from stack is nonportable */ return spi_write_then_read(ds1305->spi, buf, sizeof(buf), NULL, 0); } /* * Get/set of alarm is a bit funky: * * - First there's the inherent raciness of getting the (partitioned) * status of an alarm that could trigger while we're reading parts * of that status. * * - Second there's its limited range (we could increase it a bit by * relying on WDAY), which means it will easily roll over. * * - Third there's the choice of two alarms and alarm signals. * Here we use ALM0 and expect that nINT0 (open drain) is used; * that's the only real option for DS1306 runtime alarms, and is * natural on DS1305. * * - Fourth, there's also ALM1, and a second interrupt signal: * + On DS1305 ALM1 uses nINT1 (when INTCN=1) else nINT0; * + On DS1306 ALM1 only uses INT1 (an active high pulse) * and it won't work when VCC1 is active. * * So to be most general, we should probably set both alarms to the * same value, letting ALM1 be the wakeup event source on DS1306 * and handling several wiring options on DS1305. * * - Fifth, we support the polled mode (as well as possible; why not?) * even when no interrupt line is wired to an IRQ. */ /* * Context: caller holds rtc->ops_lock (to protect ds1305->ctrl) */ static int ds1305_get_alarm(struct device *dev, struct rtc_wkalrm *alm) { struct ds1305 *ds1305 = dev_get_drvdata(dev); struct spi_device *spi = ds1305->spi; u8 addr; int status; u8 buf[DS1305_ALM_LEN]; /* Refresh control register cache BEFORE reading ALM0 registers, * since reading alarm registers acks any pending IRQ. That * makes returning "pending" status a bit of a lie, but that bit * of EFI status is at best fragile anyway (given IRQ handlers). */ addr = DS1305_CONTROL; status = spi_write_then_read(spi, &addr, sizeof(addr), ds1305->ctrl, sizeof(ds1305->ctrl)); if (status < 0) return status; alm->enabled = !!(ds1305->ctrl[0] & DS1305_AEI0); alm->pending = !!(ds1305->ctrl[1] & DS1305_AEI0); /* get and check ALM0 registers */ addr = DS1305_ALM0(DS1305_SEC); status = spi_write_then_read(spi, &addr, sizeof(addr), buf, sizeof(buf)); if (status < 0) return status; dev_vdbg(dev, "%s: %02x %02x %02x %02x\n", "alm0 read", buf[DS1305_SEC], buf[DS1305_MIN], buf[DS1305_HOUR], buf[DS1305_WDAY]); if ((DS1305_ALM_DISABLE & buf[DS1305_SEC]) || (DS1305_ALM_DISABLE & buf[DS1305_MIN]) || (DS1305_ALM_DISABLE & buf[DS1305_HOUR])) return -EIO; /* Stuff these values into alm->time and let RTC framework code * fill in the rest ... and also handle rollover to tomorrow when * that's needed. */ alm->time.tm_sec = bcd2bin(buf[DS1305_SEC]); alm->time.tm_min = bcd2bin(buf[DS1305_MIN]); alm->time.tm_hour = bcd2hour(buf[DS1305_HOUR]); return 0; } /* * Context: caller holds rtc->ops_lock (to protect ds1305->ctrl) */ static int ds1305_set_alarm(struct device *dev, struct rtc_wkalrm *alm) { struct ds1305 *ds1305 = dev_get_drvdata(dev); struct spi_device *spi = ds1305->spi; unsigned long now, later; struct rtc_time tm; int status; u8 buf[1 + DS1305_ALM_LEN]; /* convert desired alarm to time_t */ later = rtc_tm_to_time64(&alm->time); /* Read current time as time_t */ status = ds1305_get_time(dev, &tm); if (status < 0) return status; now = rtc_tm_to_time64(&tm); /* make sure alarm fires within the next 24 hours */ if (later <= now) return -EINVAL; if ((later - now) > ds1305->rtc->alarm_offset_max) return -ERANGE; /* disable alarm if needed */ if (ds1305->ctrl[0] & DS1305_AEI0) { ds1305->ctrl[0] &= ~DS1305_AEI0; buf[0] = DS1305_WRITE | DS1305_CONTROL; buf[1] = ds1305->ctrl[0]; status = spi_write_then_read(ds1305->spi, buf, 2, NULL, 0); if (status < 0) return status; } /* write alarm */ buf[0] = DS1305_WRITE | DS1305_ALM0(DS1305_SEC); buf[1 + DS1305_SEC] = bin2bcd(alm->time.tm_sec); buf[1 + DS1305_MIN] = bin2bcd(alm->time.tm_min); buf[1 + DS1305_HOUR] = hour2bcd(ds1305->hr12, alm->time.tm_hour); buf[1 + DS1305_WDAY] = DS1305_ALM_DISABLE; dev_dbg(dev, "%s: %02x %02x %02x %02x\n", "alm0 write", buf[1 + DS1305_SEC], buf[1 + DS1305_MIN], buf[1 + DS1305_HOUR], buf[1 + DS1305_WDAY]); status = spi_write_then_read(spi, buf, sizeof(buf), NULL, 0); if (status < 0) return status; /* enable alarm if requested */ if (alm->enabled) { ds1305->ctrl[0] |= DS1305_AEI0; buf[0] = DS1305_WRITE | DS1305_CONTROL; buf[1] = ds1305->ctrl[0]; status = spi_write_then_read(ds1305->spi, buf, 2, NULL, 0); } return status; } #ifdef CONFIG_PROC_FS static int ds1305_proc(struct device *dev, struct seq_file *seq) { struct ds1305 *ds1305 = dev_get_drvdata(dev); char *diodes = "no"; char *resistors = ""; /* ctrl[2] is treated as read-only; no locking needed */ if ((ds1305->ctrl[2] & 0xf0) == DS1305_TRICKLE_MAGIC) { switch (ds1305->ctrl[2] & 0x0c) { case DS1305_TRICKLE_DS2: diodes = "2 diodes, "; break; case DS1305_TRICKLE_DS1: diodes = "1 diode, "; break; default: goto done; } switch (ds1305->ctrl[2] & 0x03) { case DS1305_TRICKLE_2K: resistors = "2k Ohm"; break; case DS1305_TRICKLE_4K: resistors = "4k Ohm"; break; case DS1305_TRICKLE_8K: resistors = "8k Ohm"; break; default: diodes = "no"; break; } } done: seq_printf(seq, "trickle_charge\t: %s%s\n", diodes, resistors); return 0; } #else #define ds1305_proc NULL #endif static const struct rtc_class_ops ds1305_ops = { .read_time = ds1305_get_time, .set_time = ds1305_set_time, .read_alarm = ds1305_get_alarm, .set_alarm = ds1305_set_alarm, .proc = ds1305_proc, .alarm_irq_enable = ds1305_alarm_irq_enable, }; static void ds1305_work(struct work_struct *work) { struct ds1305 *ds1305 = container_of(work, struct ds1305, work); struct spi_device *spi = ds1305->spi; u8 buf[3]; int status; /* lock to protect ds1305->ctrl */ rtc_lock(ds1305->rtc); /* Disable the IRQ, and clear its status ... for now, we "know" * that if more than one alarm is active, they're in sync. * Note that reading ALM data registers also clears IRQ status. */ ds1305->ctrl[0] &= ~(DS1305_AEI1 | DS1305_AEI0); ds1305->ctrl[1] = 0; buf[0] = DS1305_WRITE | DS1305_CONTROL; buf[1] = ds1305->ctrl[0]; buf[2] = 0; status = spi_write_then_read(spi, buf, sizeof(buf), NULL, 0); if (status < 0) dev_dbg(&spi->dev, "clear irq --> %d\n", status); rtc_unlock(ds1305->rtc); if (!test_bit(FLAG_EXITING, &ds1305->flags)) enable_irq(spi->irq); rtc_update_irq(ds1305->rtc, 1, RTC_AF | RTC_IRQF); } /* * This "real" IRQ handler hands off to a workqueue mostly to allow * mutex locking for ds1305->ctrl ... unlike I2C, we could issue async * I/O requests in IRQ context (to clear the IRQ status). */ static irqreturn_t ds1305_irq(int irq, void *p) { struct ds1305 *ds1305 = p; disable_irq(irq); schedule_work(&ds1305->work); return IRQ_HANDLED; } /*----------------------------------------------------------------------*/ /* * Interface for NVRAM */ static void msg_init(struct spi_message *m, struct spi_transfer *x, u8 *addr, size_t count, char *tx, char *rx) { spi_message_init(m); memset(x, 0, 2 * sizeof(*x)); x->tx_buf = addr; x->len = 1; spi_message_add_tail(x, m); x++;