// SPDX-License-Identifier: GPL-2.0-or-later /* * rtc-twl.c -- TWL Real Time Clock interface * * Copyright (C) 2007 MontaVista Software, Inc * Author: Alexandre Rusev * * Based on original TI driver twl4030-rtc.c * Copyright (C) 2006 Texas Instruments, Inc. * * Based on rtc-omap.c * Copyright (C) 2003 MontaVista Software, Inc. * Author: George G. Davis or * Copyright (C) 2006 David Brownell */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include enum twl_class { TWL_4030 = 0, TWL_6030, }; /* * RTC block register offsets (use TWL_MODULE_RTC) */ enum { REG_SECONDS_REG = 0, REG_MINUTES_REG, REG_HOURS_REG, REG_DAYS_REG, REG_MONTHS_REG, REG_YEARS_REG, REG_WEEKS_REG, REG_ALARM_SECONDS_REG, REG_ALARM_MINUTES_REG, REG_ALARM_HOURS_REG, REG_ALARM_DAYS_REG, REG_ALARM_MONTHS_REG, REG_ALARM_YEARS_REG, REG_RTC_CTRL_REG, REG_RTC_STATUS_REG, REG_RTC_INTERRUPTS_REG, REG_RTC_COMP_LSB_REG, REG_RTC_COMP_MSB_REG, }; static const u8 twl4030_rtc_reg_map[] = { [REG_SECONDS_REG] = 0x00, [REG_MINUTES_REG] = 0x01, [REG_HOURS_REG] = 0x02, [REG_DAYS_REG] = 0x03, [REG_MONTHS_REG] = 0x04, [REG_YEARS_REG] = 0x05, [REG_WEEKS_REG] = 0x06, [REG_ALARM_SECONDS_REG] = 0x07, [REG_ALARM_MINUTES_REG] = 0x08, [REG_ALARM_HOURS_REG] = 0x09, [REG_ALARM_DAYS_REG] = 0x0A, [REG_ALARM_MONTHS_REG] = 0x0B, [REG_ALARM_YEARS_REG] = 0x0C, [REG_RTC_CTRL_REG] = 0x0D, [REG_RTC_STATUS_REG] = 0x0E, [REG_RTC_INTERRUPTS_REG] = 0x0F, [REG_RTC_COMP_LSB_REG] = 0x10, [REG_RTC_COMP_MSB_REG] = 0x11, }; static const u8 twl6030_rtc_reg_map[] = { [REG_SECONDS_REG] = 0x00, [REG_MINUTES_REG] = 0x01, [REG_HOURS_REG] = 0x02, [REG_DAYS_REG] = 0x03, [REG_MONTHS_REG] = 0x04, [REG_YEARS_REG] = 0x05, [REG_WEEKS_REG] = 0x06, [REG_ALARM_SECONDS_REG] = 0x08, [REG_ALARM_MINUTES_REG] = 0x09, [REG_ALARM_HOURS_REG] = 0x0A, [REG_ALARM_DAYS_REG] = 0x0B, [REG_ALARM_MONTHS_REG] = 0x0C, [REG_ALARM_YEARS_REG] = 0x0D, [REG_RTC_CTRL_REG] = 0x10, [REG_RTC_STATUS_REG] = 0x11, [REG_RTC_INTERRUPTS_REG] = 0x12, [REG_RTC_COMP_LSB_REG] = 0x13, [REG_RTC_COMP_MSB_REG] = 0x14, }; /* RTC_CTRL_REG bitfields */ #define BIT_RTC_CTRL_REG_STOP_RTC_M 0x01 #define BIT_RTC_CTRL_REG_ROUND_30S_M 0x02 #define BIT_RTC_CTRL_REG_AUTO_COMP_M 0x04 #define BIT_RTC_CTRL_REG_MODE_12_24_M 0x08 #define BIT_RTC_CTRL_REG_TEST_MODE_M 0x10 #define BIT_RTC_CTRL_REG_SET_32_COUNTER_M 0x20 #define BIT_RTC_CTRL_REG_GET_TIME_M 0x40 #define BIT_RTC_CTRL_REG_RTC_V_OPT 0x80 /* RTC_STATUS_REG bitfields */ #define BIT_RTC_STATUS_REG_RUN_M 0x02 #define BIT_RTC_STATUS_REG_1S_EVENT_M 0x04 #define BIT_RTC_STATUS_REG_1M_EVENT_M 0x08 #define BIT_RTC_STATUS_REG_1H_EVENT_M 0x10 #define BIT_RTC_STATUS_REG_1D_EVENT_M 0x20 #define BIT_RTC_STATUS_REG_ALARM_M 0x40 #define BIT_RTC_STATUS_REG_POWER_UP_M 0x80 /* RTC_INTERRUPTS_REG bitfields */ #define BIT_RTC_INTERRUPTS_REG_EVERY_M 0x03 #define BIT_RTC_INTERRUPTS_REG_IT_TIMER_M 0x04 #define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M 0x08 /* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */ #define ALL_TIME_REGS 6 /*----------------------------------------------------------------------*/ struct twl_rtc { struct device *dev; struct rtc_device *rtc; u8 *reg_map; /* * Cache the value for timer/alarm interrupts register; this is * only changed by callers holding rtc ops lock (or resume). */ unsigned char rtc_irq_bits; bool wake_enabled; #ifdef CONFIG_PM_SLEEP unsigned char irqstat; #endif enum twl_class class; }; /* * Supports 1 byte read from TWL RTC register. */ static int twl_rtc_read_u8(struct twl_rtc *twl_rtc, u8 *data, u8 reg) { int ret; ret = twl_i2c_read_u8(TWL_MODULE_RTC, data, (twl_rtc->reg_map[reg])); if (ret < 0) pr_err("Could not read TWL register %X - error %d\n", reg, ret); return ret; } /* * Supports 1 byte write to TWL RTC registers. */ static int twl_rtc_write_u8(struct twl_rtc *twl_rtc, u8 data, u8 reg) { int ret; ret = twl_i2c_write_u8(TWL_MODULE_RTC, data, (twl_rtc->reg_map[reg])); if (ret < 0) pr_err("Could not write TWL register %X - error %d\n", reg, ret); return ret; } /* * Enable 1/second update and/or alarm interrupts. */ static int set_rtc_irq_bit(struct twl_rtc *twl_rtc, unsigned char bit) { unsigned char val; int ret; /* if the bit is set, return from here */ if (twl_rtc->rtc_irq_bits & bit) return 0; val = twl_rtc->rtc_irq_bits | bit; val &= ~BIT_RTC_INTERRUPTS_REG_EVERY_M; ret = twl_rtc_write_u8(twl_rtc, val, REG_RTC_INTERRUPTS_REG); if (ret == 0) twl_rtc->rtc_irq_bits = val; return ret; } /* * Disable update and/or alarm interrupts. */ static int mask_rtc_irq_bit(struct twl_rtc *twl_rtc, unsigned char bit) { unsigned char val; int ret; /* if the bit is clear, return from here */ if (!(twl_rtc->rtc_irq_bits & bit)) return 0; val = twl_rtc->rtc_irq_bits & ~bit; ret = twl_rtc_write_u8(twl_rtc, val, REG_RTC_INTERRUPTS_REG); if (ret == 0) twl_rtc->rtc_irq_bits = val; return ret; } static int twl_rtc_alarm_irq_enable(struct device *dev, unsigned enabled) { struct platform_device *pdev = to_platform_device(dev); struct twl_rtc *twl_rtc = dev_get_drvdata(dev); int irq = platform_get_irq(pdev, 0); int ret; if (enabled) { ret = set_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_ALARM_M); if (device_can_wakeup(dev) && !twl_rtc->wake_enabled) { enable_irq_wake(irq); twl_rtc->wake_enabled = true; } } else { ret = mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_ALARM_M); if (twl_rtc->wake_enabled) { disable_irq_wake(irq); twl_rtc->wake_enabled = false; } } return ret; } /* * Gets current TWL RTC time and date parameters. * * The RTC's time/alarm representation is not what gmtime(3) requires * Linux to use: * * - Months are 1..12 vs Linux 0-11 * - Years are 0..99 vs Linux 1900..N (we assume 21st century) */ static int twl_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct twl_rtc *twl_rtc = dev_get_drvdata(dev); unsigned char rtc_data[ALL_TIME_REGS]; int ret; u8 save_control; u8 rtc_control; ret = twl_rtc_read_u8(twl_rtc, &save_control, REG_RTC_CTRL_REG); if (ret < 0) { dev_err(dev, "%s: reading CTRL_REG, error %d\n", __func__, ret); return ret; } /* for twl6030/32 make sure BIT_RTC_CTRL_REG_GET_TIME_M is clear */ if (twl_rtc->class == TWL_6030) { if (save_control & BIT_RTC_CTRL_REG_GET_TIME_M) { save_control &= ~BIT_RTC_CTRL_REG_GET_TIME_M; ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG); if (ret < 0) { dev_err(dev, "%s clr GET_TIME, error %d\n", __func__, ret); return ret; } } } /* Copy RTC counting registers to static registers or latches */ rtc_control = save_control | BIT_RTC_CTRL_REG_GET_TIME_M; /* for twl6030/32 enable read access to static shadowed registers */ if (twl_rtc->class == TWL_6030) rtc_control |= BIT_RTC_CTRL_REG_RTC_V_OPT; ret = twl_rtc_write_u8(twl_rtc, rtc_control, REG_RTC_CTRL_REG); if (ret < 0) { dev_err(dev, "%s: writing CTRL_REG, error %d\n", __func__, ret); return ret; } ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data, (twl_rtc->reg_map[REG_SECONDS_REG]), ALL_TIME_REGS); if (ret < 0) { dev_err(dev, "%s: reading data, error %d\n", __func__, ret); return ret; } /* for twl6030 restore original state of rtc control register */ if (twl_rtc->class == TWL_6030) { ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG); if (ret < 0) { dev_err(dev, "%s: restore CTRL_REG, error %d\n", __func__, ret); return ret; } } tm->tm_sec = bcd2bin(rtc_data[0]); tm->tm_min = bcd2bin(rtc_data[1]); tm->tm_hour = bcd2bin(rtc_data[2]); tm->tm_mday = bcd2bin(rtc_data[3]); tm->tm_mon = bcd2bin(rtc_data[4]) - 1; tm->tm_year = bcd2bin(rtc_data[5]) + 100; return ret; } static int twl_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct twl_rtc *twl_rtc = dev_get_drvdata(dev); unsigned char save_control; unsigned char rtc_data[ALL_TIME_REGS]; int ret; rtc_data[0] = bin2bcd(tm->tm_sec); rtc_data[1] = bin2bcd(tm->tm_min); rtc_data[2] = bin2bcd(tm->tm_hour); rtc_data[3] = bin2bcd(tm->tm_mday); rtc_data[4] = bin2bcd(tm->tm_mon + 1); rtc_data[5] = bin2bcd(tm->tm_year - 100); /* Stop RTC while updating the TC registers */ ret = twl_rtc_read_u8(twl_rtc, &save_control, REG_RTC_CTRL_REG); if (ret < 0) goto out; save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M; ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG); if (ret < 0) goto out; /* update all the time registers in one shot */ ret = twl_i2c_write(TWL_MODULE_RTC, rtc_data, (twl_rtc->reg_map[REG_SECONDS_REG]), ALL_TIME_REGS); if (ret < 0) { dev_err(dev, "rtc_set_time error %d\n", ret); goto out; } /* Start back RTC */ save_control |= BIT_RTC_CTRL_REG_STOP_RTC_M; ret = twl_rtc_write_u8(twl_rtc, save_control, REG_RTC_CTRL_REG); out: return ret; } /* * Gets current TWL RTC alarm time. */ static int twl_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) { struct twl_rtc *twl_rtc = dev_get_drvdata(dev); unsigned char rtc_data[ALL_TIME_REGS]; int ret; ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data, twl_rtc->reg_map[REG_ALARM_SECONDS_REG], ALL_TIME_REGS); if (ret < 0) { dev_err(dev, "rtc_read_alarm error %d\n", ret); return ret; } /* some of these fields may be wildcard/"match all" */ alm->time.tm_sec = bcd2bin(rtc_data[0]); alm->time.tm_min = bcd2bin(rtc_data[1]); alm->time.tm_hour = bcd2bin(rtc_data[2]); alm->time.tm_mday = bcd2bin(rtc_data[3]); alm->time.tm_mon = bcd2bin(rtc_data[4]) - 1; alm->time.tm_year = bcd2bin(rtc_data[5]) + 100; /* report cached alarm enable state */ if (twl_rtc->rtc_irq_bits & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M) alm->enabled = 1; return ret; } static int twl_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) { struct twl_rtc *twl_rtc = dev_get_drvdata(dev); unsigned char alarm_data[ALL_TIME_REGS]; int ret; ret = twl_rtc_alarm_irq_enable(dev, 0); if (ret) goto out; alarm_data[0] = bin2bcd(alm->time.tm_sec); alarm_data[1] = bin2bcd(alm->time.tm_min); alarm_data[2] = bin2bcd(alm->time.tm_hour); alarm_data[3] = bin2bcd(alm->time.tm_mday); alarm_data[4] = bin2bcd(alm->time.tm_mon + 1); alarm_data[5] = bin2bcd(alm->time.tm_year - 100); /* update all the alarm registers in one shot */ ret = twl_i2c_write(TWL_MODULE_RTC, alarm_data, twl_rtc->reg_map[REG_ALARM_SECONDS_REG], ALL_TIME_REGS); if (ret) { dev_err(dev, "rtc_set_alarm error %d\n", ret); goto out; } if (alm->enabled) ret = twl_rtc_alarm_irq_enable(dev, 1); out: return ret; } static irqreturn_t twl_rtc_interrupt(int irq, void *data) { struct twl_rtc *twl_rtc = data; unsigned long events; int ret = IRQ_NONE; int res; u8 rd_reg; res = twl_rtc_read_u8(twl_rtc, &rd_reg, REG_RTC_STATUS_REG); if (res) goto out; /* * Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG. * only one (ALARM or RTC) interrupt source may be enabled * at time, we also could check our results * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM] */ if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M) events = RTC_IRQF | RTC_AF; else events = RTC_IRQF | RTC_PF; res = twl_rtc_write_u8(twl_rtc, BIT_RTC_STATUS_REG_ALARM_M, REG_RTC_STATUS_REG); if (res) goto out; if (twl_rtc->class == TWL_4030) { /* Clear on Read enabled. RTC_IT bit of TWL4030_INT_PWR_ISR1 * needs 2 reads to clear the interrupt. One read is done in * do_twl_pwrirq(). Doing the second read, to clear * the bit. * * FIXME the reason PWR_ISR1 needs an extra read is that * RTC_IF retriggered until we cleared REG_ALARM_M above. * But re-reading like this is a bad hack; by doing so we * risk wrongly clearing status for some other IRQ (losing * the interrupt). Be smarter about handling RTC_UF ... */ res = twl_i2c_read_u8(TWL4030_MODULE_INT, &rd_reg, TWL4030_INT_PWR_ISR1); if (res) goto out; } /* Notify RTC core on event */ rtc_update_irq(twl_rtc->rtc, 1, events); ret = IRQ_HANDLED; out: return ret; } static const struct rtc_class_ops twl_rtc_ops = { .read_time = twl_rtc_read_time, .set_time = twl_rtc_set_time, .read_alarm = twl_rtc_read_alarm, .set_alarm = twl_rtc_set_alarm, .alarm_irq_enable = twl_rtc_alarm_irq_enable, }; static int twl_nvram_read(void *priv, unsigned int offset, void *val, size_t bytes) { return twl_i2c_read((long)priv, val, offset, bytes); } static int twl_nvram_write(void *priv, unsigned int offset, void *val, size_t bytes) { return twl_i2c_write((long)priv, val, offset, bytes); } /*----------------------------------------------------------------------*/ static int twl_rtc_probe(struct platform_device *pdev) { struct twl_rtc *twl_rtc; struct nvmem_config nvmem_cfg; struct device_node *np = pdev->dev.of_node; int ret = -EINVAL; int irq = platform_get_irq(pdev, 0); u8 rd_reg; if (!np) { dev_err(&pdev->dev, "no DT info\n"); return -EINVAL; } if (irq <= 0) return ret; twl_rtc = devm_kzalloc(&pdev->dev, sizeof(*twl_rtc), GFP_KERNEL); if (!twl_rtc) return -ENOMEM; if (twl_class_is_4030()) { twl_rtc->class = TWL_4030; twl_rtc->reg_map = (u8 *)twl4030_rtc_reg_map; } else if (twl_class_is_6030()) { twl_rtc->class = TWL_6030; twl_rtc->reg_map = (u8 *)twl6030_rtc_reg_map; } else { dev_err(&pdev->dev, "TWL Class not supported.\n"); return -EINVAL; } ret = twl_rtc_read_u8(twl_rtc, &rd_reg, REG_RTC_STATUS_REG); if (ret < 0) return ret; if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M) dev_warn(&pdev->dev, "Power up reset detected.\n"); if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M) dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n"); /* Clear RTC Power up reset and pending alarm interrupts */ ret = twl_rtc_write_u8(twl_rtc, rd_reg, REG_RTC_STATUS_REG); if (ret < 0) return ret; if (twl_rtc->class == TWL_6030) { twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK, REG_INT_MSK_LINE_A); twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK, REG_INT_MSK_STS_A); } ret = twl_rtc_write_u8(twl_rtc, BIT_RTC_CTRL_REG_STOP_RTC_M, REG_RTC_CTRL_REG); if (ret < 0) return ret; /* ensure interrupts are disabled, bootloaders can be strange */ ret = twl_rtc_write_u8(twl_rtc, 0, REG_RTC_INTERRUPTS_REG); if (ret < 0) dev_warn(&pdev->dev, "unable to disable interrupt\n"); /* init cached IRQ enable bits */ ret = twl_rtc_read_u8(twl_rtc, &twl_rtc->rtc_irq_bits, REG_RTC_INTERRUPTS_REG); if (ret < 0) return ret; platform_set_drvdata(pdev, twl_rtc); device_init_wakeup(&pdev->dev, 1); twl_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &twl_rtc_ops, THIS_MODULE); if (IS_ERR(twl_rtc->rtc)) return PTR_ERR(twl_rtc->rtc); ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, twl_rtc_interrupt, IRQF_TRIGGER_RISING | IRQF_ONESHOT, dev_name(&twl_rtc->rtc->dev), twl_rtc); if (ret < 0) { dev_err(&pdev->dev, "IRQ is not free.\n"); return ret; } memset(&nvmem_cfg, 0, sizeof(nvmem_cfg)); nvmem_cfg.name = "twl-secured-"; nvmem_cfg.type = NVMEM_TYPE_BATTERY_BACKED; nvmem_cfg.reg_read = twl_nvram_read, nvmem_cfg.reg_write = twl_nvram_write, nvmem_cfg.word_size = 1; nvmem_cfg.stride = 1; if (twl_class_is_4030()) { /* 20 bytes SECURED_REG area */ nvmem_cfg.size = 20; nvmem_cfg.priv = (void *)TWL_MODULE_SECURED_REG; devm_rtc_nvmem_register(twl_rtc->rtc, &nvmem_cfg); /* 8 bytes BACKUP area */ nvmem_cfg.name = "twl-backup-"; nvmem_cfg.size = 8; nvmem_cfg.priv = (void *)TWL4030_MODULE_BACKUP; devm_rtc_nvmem_register(twl_rtc->rtc, &nvmem_cfg); } else { /* 8 bytes SECURED_REG area */ nvmem_cfg.size = 8; nvmem_cfg.priv = (void *)TWL_MODULE_SECURED_REG; devm_rtc_nvmem_register(twl_rtc->rtc, &nvmem_cfg); } return 0; } /* * Disable all TWL RTC module interrupts. * Sets status flag to free. */ static void twl_rtc_remove(struct platform_device *pdev) { struct twl_rtc *twl_rtc = platform_get_drvdata(pdev); /* leave rtc running, but disable irqs */ mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_ALARM_M); mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M); if (twl_rtc->class == TWL_6030) { twl6030_interrupt_mask(TWL6030_RTC_INT_MASK, REG_INT_MSK_LINE_A); twl6030_interrupt_mask(TWL6030_RTC_INT_MASK, REG_INT_MSK_STS_A); } } static void twl_rtc_shutdown(struct platform_device *pdev) { struct twl_rtc *twl_rtc = platform_get_drvdata(pdev); /* mask timer interrupts, but leave alarm interrupts on to enable power-on when alarm is triggered */ mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M); } #ifdef CONFIG_PM_SLEEP static int twl_rtc_suspend(struct device *dev) { struct twl_rtc *twl_rtc = dev_get_drvdata(dev); twl_rtc->irqstat = twl_rtc->rtc_irq_bits; mask_rtc_irq_bit(twl_rtc, BIT_RTC_INTERRUPTS_REG_IT_TIMER_M); return 0; } static int twl_rtc_resume(struct device *dev) { struct twl_rtc *twl_rtc = dev_get_drvdata(dev); set_rtc_irq_bit(twl_rtc, twl_rtc->irqstat); return 0; } #endif static SIMPLE_DEV_PM_OPS(twl_rtc_pm_ops, twl_rtc_suspend, twl_rtc_resume); static const struct of_device_id twl_rtc_of_match[] = { {.compatible = "ti,twl4030-rtc", }, { }, }; MODULE_DEVICE_TABLE(of, twl_rtc_of_match); static struct platform_driver twl4030rtc_driver = { .probe = twl_rtc_probe, .remove_new = twl_rtc_remove, .shutdown = twl_rtc_shutdown, .driver = { .name = "twl_rtc", .pm = &twl_rtc_pm_ops, .of_match_table = twl_rtc_of_match, }, }; module_platform_driver(twl4030rtc_driver); MODULE_AUTHOR("Texas Instruments, MontaVista Software"); MODULE_LICENSE("GPL");