diff options
Diffstat (limited to 'drivers/rtc/rtc-88pm860x.c')
| -rw-r--r-- | drivers/rtc/rtc-88pm860x.c | 427 |
1 files changed, 427 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-88pm860x.c b/drivers/rtc/rtc-88pm860x.c new file mode 100644 index 000000000000..64b847b7f970 --- /dev/null +++ b/drivers/rtc/rtc-88pm860x.c @@ -0,0 +1,427 @@ +/* + * Real Time Clock driver for Marvell 88PM860x PMIC + * + * Copyright (c) 2010 Marvell International Ltd. + * Author: Haojian Zhuang <haojian.zhuang@marvell.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/module.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; + int (*sync)(unsigned int ticks); +}; + +#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, ALARM); + else + pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM, 0); + return 0; +} + +/* + * Calculate the next alarm time given the requested alarm time mask + * and the current time. + */ +static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, + struct rtc_time *alrm) +{ + unsigned long next_time; + unsigned long now_time; + + next->tm_year = now->tm_year; + next->tm_mon = now->tm_mon; + next->tm_mday = now->tm_mday; + next->tm_hour = alrm->tm_hour; + next->tm_min = alrm->tm_min; + next->tm_sec = alrm->tm_sec; + + rtc_tm_to_time(now, &now_time); + rtc_tm_to_time(next, &next_time); + + if (next_time < now_time) { + /* Advance one day */ + next_time += 60 * 60 * 24; + rtc_time_to_tm(next_time, next); + } +} + +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 = (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 = (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_time_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; + + if ((tm->tm_year < 70) || (tm->tm_year > 138)) { + dev_dbg(info->dev, "Set time %d out of range. " + "Please set time between 1970 to 2038.\n", + 1900 + tm->tm_year); + return -EINVAL; + } + rtc_tm_to_time(tm, &ticks); + + /* load 32-bit read-only counter */ + pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); + data = (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); + + if (info->sync) + info->sync(ticks); + 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 = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7]; + + pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf); + data = (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_time_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); + struct rtc_time now_tm, alarm_tm; + 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 = (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 = (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_time_to_tm(ticks, &now_tm); + rtc_next_alarm_time(&alarm_tm, &now_tm, &alrm->time); + /* get new ticks for alarm in 24 hours */ + rtc_tm_to_time(&alarm_tm, &ticks); + 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 + +static int __devinit pm860x_rtc_probe(struct platform_device *pdev) +{ + struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); + struct pm860x_rtc_pdata *pdata = NULL; + struct pm860x_rtc_info *info; + struct rtc_time tm; + unsigned long ticks = 0; + int ret; + + pdata = pdev->dev.platform_data; + if (pdata == NULL) + dev_warn(&pdev->dev, "No platform data!\n"); + + info = kzalloc(sizeof(struct pm860x_rtc_info), GFP_KERNEL); + if (!info) + return -ENOMEM; + info->irq = platform_get_irq(pdev, 0); + if (info->irq < 0) { + dev_err(&pdev->dev, "No IRQ resource!\n"); + ret = -EINVAL; + goto out; + } + + info->chip = chip; + info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion; + info->dev = &pdev->dev; + dev_set_drvdata(&pdev->dev, info); + + ret = request_threaded_irq(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); + goto out; + } + + /* 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); + + ret = pm860x_rtc_read_time(&pdev->dev, &tm); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to read initial time.\n"); + goto out_rtc; + } + if ((tm.tm_year < 70) || (tm.tm_year > 138)) { + tm.tm_year = 70; + tm.tm_mon = 0; + tm.tm_mday = 1; + tm.tm_hour = 0; + tm.tm_min = 0; + tm.tm_sec = 0; + ret = pm860x_rtc_set_time(&pdev->dev, &tm); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to set initial time.\n"); + goto out_rtc; + } + } + rtc_tm_to_time(&tm, &ticks); + if (pdata && pdata->sync) { + pdata->sync(ticks); + info->sync = pdata->sync; + } + + info->rtc_dev = rtc_device_register("88pm860x-rtc", &pdev->dev, + &pm860x_rtc_ops, THIS_MODULE); + ret = PTR_ERR(info->rtc_dev); + if (IS_ERR(info->rtc_dev)) { + dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); + goto out_rtc; + } + + /* + * 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 */ + if (pdata && pdata->vrtc) + info->vrtc = pdata->vrtc & 0x3; + else + info->vrtc = 1; + 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 */ + return 0; +out_rtc: + free_irq(info->irq, info); +out: + kfree(info); + return ret; +} + +static int __devexit pm860x_rtc_remove(struct platform_device *pdev) +{ + struct pm860x_rtc_info *info = platform_get_drvdata(pdev); + +#ifdef VRTC_CALIBRATION + flush_scheduled_work(); + /* disable measurement */ + pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); +#endif /* VRTC_CALIBRATION */ + + platform_set_drvdata(pdev, NULL); + rtc_device_unregister(info->rtc_dev); + free_irq(info->irq, info); + kfree(info); + return 0; +} + +static struct platform_driver pm860x_rtc_driver = { + .driver = { + .name = "88pm860x-rtc", + .owner = THIS_MODULE, + }, + .probe = pm860x_rtc_probe, + .remove = __devexit_p(pm860x_rtc_remove), +}; + +static int __init pm860x_rtc_init(void) +{ + return platform_driver_register(&pm860x_rtc_driver); +} +module_init(pm860x_rtc_init); + +static void __exit pm860x_rtc_exit(void) +{ + platform_driver_unregister(&pm860x_rtc_driver); +} +module_exit(pm860x_rtc_exit); + +MODULE_DESCRIPTION("Marvell 88PM860x RTC driver"); +MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); +MODULE_LICENSE("GPL"); |