// SPDX-License-Identifier: GPL-2.0-only /* * Real Time Clock driver for Marvell 88PM860x PMIC * * Copyright (c) 2010 Marvell International Ltd. * Author: Haojian Zhuang <haojian.zhuang@marvell.com> */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/mutex.h> #include <linux/rtc.h> #include <linux/delay.h> #include <linux/mfd/core.h> #include <linux/mfd/88pm860x.h> #define VRTC_CALIBRATION struct pm860x_rtc_info { struct pm860x_chip *chip; struct i2c_client *i2c; struct rtc_device *rtc_dev; struct device *dev; struct delayed_work calib_work; int irq; int vrtc; }; #define REG_VRTC_MEAS1 0x7D #define REG0_ADDR 0xB0 #define REG1_ADDR 0xB2 #define REG2_ADDR 0xB4 #define REG3_ADDR 0xB6 #define REG0_DATA 0xB1 #define REG1_DATA 0xB3 #define REG2_DATA 0xB5 #define REG3_DATA 0xB7 /* bit definitions of Measurement Enable Register 2 (0x51) */ #define MEAS2_VRTC (1 << 0) /* bit definitions of RTC Register 1 (0xA0) */ #define ALARM_EN (1 << 3) #define ALARM_WAKEUP (1 << 4) #define ALARM (1 << 5) #define RTC1_USE_XO (1 << 7) #define VRTC_CALIB_INTERVAL (HZ * 60 * 10) /* 10 minutes */ static irqreturn_t rtc_update_handler(int irq, void *data) { struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data; int mask; mask = ALARM | ALARM_WAKEUP; pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask); rtc_update_irq(info->rtc_dev, 1, RTC_AF); return IRQ_HANDLED; } static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct pm860x_rtc_info *info = dev_get_drvdata(dev); if (enabled) pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, ALARM_EN); else pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0); return 0; } static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct pm860x_rtc_info *info = dev_get_drvdata(dev); unsigned char buf[8]; unsigned long ticks, base, data; pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7]; /* load 32-bit read-only counter */ pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; ticks = base + data; dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", base, data, ticks); rtc_time64_to_tm(ticks, tm); return 0; } static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct pm860x_rtc_info *info = dev_get_drvdata(dev); unsigned char buf[4]; unsigned long ticks, base, data; ticks = rtc_tm_to_time64(tm); /* load 32-bit read-only counter */ pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; base = ticks - data; dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", base, data, ticks); pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF); pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF); pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF); pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF); return 0; } static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct pm860x_rtc_info *info = dev_get_drvdata(dev); unsigned char buf[8]; unsigned long ticks, base, data; int ret; pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7]; pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf); data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; ticks = base + data; dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", base, data, ticks); rtc_time64_to_tm(ticks, &alrm->time); ret = pm860x_reg_read(info->i2c, PM8607_RTC1); alrm->enabled = (ret & ALARM_EN) ? 1 : 0; alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0; return 0; } static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct pm860x_rtc_info *info = dev_get_drvdata(dev); unsigned long ticks, base, data; unsigned char buf[8]; int mask; pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0); pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7]; ticks = rtc_tm_to_time64(&alrm->time); data = ticks - base; buf[0] = data & 0xff; buf[1] = (data >> 8) & 0xff; buf[2] = (data >> 16) & 0xff; buf[3] = (data >> 24) & 0xff; pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf); if (alrm->enabled) { mask = ALARM | ALARM_WAKEUP | ALARM_EN; pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask); } else { mask = ALARM | ALARM_WAKEUP | ALARM_EN; pm860x_set_bits(info->i2c, PM8607_RTC1, mask, ALARM | ALARM_WAKEUP); } return 0; } static const struct rtc_class_ops pm860x_rtc_ops = { .read_time = pm860x_rtc_read_time, .set_time = pm860x_rtc_set_time, .read_alarm = pm860x_rtc_read_alarm, .set_alarm = pm860x_rtc_set_alarm, .alarm_irq_enable = pm860x_rtc_alarm_irq_enable, }; #ifdef VRTC_CALIBRATION static void calibrate_vrtc_work(struct work_struct *work) { struct pm860x_rtc_info *info = container_of(work, struct pm860x_rtc_info, calib_work.work); unsigned char buf[2]; unsigned int sum, data, mean, vrtc_set; int i; for (i = 0, sum = 0; i < 16; i++) { msleep(100); pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf); data = (buf[0] << 4) | buf[1]; data = (data * 5400) >> 12; /* convert to mv */ sum += data; } mean = sum >> 4; vrtc_set = 2700 + (info->vrtc & 0x3) * 200; dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set); sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1); data = sum & 0x3; if ((mean + 200) < vrtc_set) { /* try higher voltage */ if (++data == 4) goto out; data = (sum & 0xf8) | (data & 0x3); pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data); } else if ((mean - 200) > vrtc_set) { /* try lower voltage */ if (data-- == 0) goto out; data = (sum & 0xf8) | (data & 0x3); pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data); } else goto out; dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data); /* trigger next calibration since VRTC is updated */ schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL); return; out: /* disable measurement */ pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); dev_dbg(info->dev, "finish VRTC calibration\n"); return; } #endif #ifdef CONFIG_OF static int pm860x_rtc_dt_init(struct platform_device *pdev, struct pm860x_rtc_info *info) { struct device_node *np = pdev->dev.parent->of_node; int ret; if (!np) return -ENODEV; np = of_get_child_by_name(np, "rtc"); if (!np) { dev_err(&pdev->dev, "failed to find rtc node\n"); return -ENODEV; } ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc); if (ret) info->vrtc = 0; of_node_put(np); return 0; } #else #define pm860x_rtc_dt_init(x, y) do { } while (0) #endif static int pm860x_rtc_probe(struct platform_device *pdev) { struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); struct pm860x_rtc_info *info; int ret; info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info), GFP_KERNEL); if (!info) return -ENOMEM; info->irq = platform_get_irq(pdev, 0); if (info->irq < 0) return info->irq; info->chip = chip; info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion; info->dev = &pdev->dev; dev_set_drvdata(&pdev->dev, info); info->rtc_dev = devm_rtc_allocate_device(&pdev->dev); if (IS_ERR(info->rtc_dev)) return PTR_ERR(info->rtc_dev); ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL, rtc_update_handler, IRQF_ONESHOT, "rtc", info); if (ret < 0) { dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n", info->irq, ret); return ret; } /* set addresses of 32-bit base value for RTC time */ pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA); pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA); pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA); pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA); pm860x_rtc_dt_init(pdev, info); info->rtc_dev->ops = &pm860x_rtc_ops; info->rtc_dev->range_max = U32_MAX; ret = devm_rtc_register_device(info->rtc_dev); if (ret) return ret; /* * enable internal XO instead of internal 3.25MHz clock since it can * free running in PMIC power-down state. */ pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO); #ifdef VRTC_CALIBRATION /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */ pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC); /* calibrate VRTC */ INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work); schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL); #endif /* VRTC_CALIBRATION */ device_init_wakeup(&pdev->dev, 1); return 0; } static int pm860x_rtc_remove(struct platform_device *pdev) { struct pm860x_rtc_info *info = platform_get_drvdata(pdev); #ifdef VRTC_CALIBRATION cancel_delayed_work_sync(&info->calib_work); /* disable measurement */ pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); #endif /* VRTC_CALIBRATION */ return 0; } #ifdef CONFIG_PM_SLEEP static int pm860x_rtc_suspend(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); if (device_may_wakeup(dev)) chip->wakeup_flag |= 1 << PM8607_IRQ_RTC; return 0; } static int pm860x_rtc_resume(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); if (device_may_wakeup(dev)) chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC); return 0; } #endif static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume); static struct platform_driver pm860x_rtc_driver = { .driver = { .name = "88pm860x-rtc", .pm = &pm860x_rtc_pm_ops, }, .probe = pm860x_rtc_probe, .remove = pm860x_rtc_remove, }; module_platform_driver(pm860x_rtc_driver); MODULE_DESCRIPTION("Marvell 88PM860x RTC driver"); MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); MODULE_LICENSE("GPL");