| // 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 void 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 */ |
| } |
| |
| #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"); |