diff options
Diffstat (limited to 'drivers/rtc/rtc-palmas.c')
| -rw-r--r-- | drivers/rtc/rtc-palmas.c | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-palmas.c b/drivers/rtc/rtc-palmas.c new file mode 100644 index 000000000..67571f7f0 --- /dev/null +++ b/drivers/rtc/rtc-palmas.c @@ -0,0 +1,363 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * rtc-palmas.c -- Palmas Real Time Clock driver. + + * RTC driver for TI Palma series devices like TPS65913, + * TPS65914 power management IC. + * + * Copyright (c) 2012, NVIDIA Corporation. + * + * Author: Laxman Dewangan <ldewangan@nvidia.com> + */ + +#include <linux/bcd.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/mfd/palmas.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/rtc.h> +#include <linux/types.h> +#include <linux/platform_device.h> +#include <linux/pm.h> + +struct palmas_rtc { + struct rtc_device *rtc; + struct device *dev; + unsigned int irq; +}; + +/* Total number of RTC registers needed to set time*/ +#define PALMAS_NUM_TIME_REGS (PALMAS_YEARS_REG - PALMAS_SECONDS_REG + 1) + +static int palmas_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + unsigned char rtc_data[PALMAS_NUM_TIME_REGS]; + struct palmas *palmas = dev_get_drvdata(dev->parent); + int ret; + + /* Copy RTC counting registers to static registers or latches */ + ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG, + PALMAS_RTC_CTRL_REG_GET_TIME, PALMAS_RTC_CTRL_REG_GET_TIME); + if (ret < 0) { + dev_err(dev, "RTC CTRL reg update failed, err: %d\n", ret); + return ret; + } + + ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG, + rtc_data, PALMAS_NUM_TIME_REGS); + if (ret < 0) { + dev_err(dev, "RTC_SECONDS reg read failed, err = %d\n", 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 palmas_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + unsigned char rtc_data[PALMAS_NUM_TIME_REGS]; + struct palmas *palmas = dev_get_drvdata(dev->parent); + 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 RTC time registers */ + ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG, + PALMAS_RTC_CTRL_REG_STOP_RTC, 0); + if (ret < 0) { + dev_err(dev, "RTC stop failed, err = %d\n", ret); + return ret; + } + + ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG, + rtc_data, PALMAS_NUM_TIME_REGS); + if (ret < 0) { + dev_err(dev, "RTC_SECONDS reg write failed, err = %d\n", ret); + return ret; + } + + /* Start back RTC */ + ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG, + PALMAS_RTC_CTRL_REG_STOP_RTC, PALMAS_RTC_CTRL_REG_STOP_RTC); + if (ret < 0) + dev_err(dev, "RTC start failed, err = %d\n", ret); + return ret; +} + +static int palmas_rtc_alarm_irq_enable(struct device *dev, unsigned enabled) +{ + struct palmas *palmas = dev_get_drvdata(dev->parent); + u8 val; + + val = enabled ? PALMAS_RTC_INTERRUPTS_REG_IT_ALARM : 0; + return palmas_write(palmas, PALMAS_RTC_BASE, + PALMAS_RTC_INTERRUPTS_REG, val); +} + +static int palmas_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + unsigned char alarm_data[PALMAS_NUM_TIME_REGS]; + u32 int_val; + struct palmas *palmas = dev_get_drvdata(dev->parent); + int ret; + + ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE, + PALMAS_ALARM_SECONDS_REG, + alarm_data, PALMAS_NUM_TIME_REGS); + if (ret < 0) { + dev_err(dev, "RTC_ALARM_SECONDS read failed, err = %d\n", ret); + return ret; + } + + alm->time.tm_sec = bcd2bin(alarm_data[0]); + alm->time.tm_min = bcd2bin(alarm_data[1]); + alm->time.tm_hour = bcd2bin(alarm_data[2]); + alm->time.tm_mday = bcd2bin(alarm_data[3]); + alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1; + alm->time.tm_year = bcd2bin(alarm_data[5]) + 100; + + ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_INTERRUPTS_REG, + &int_val); + if (ret < 0) { + dev_err(dev, "RTC_INTERRUPTS reg read failed, err = %d\n", ret); + return ret; + } + + if (int_val & PALMAS_RTC_INTERRUPTS_REG_IT_ALARM) + alm->enabled = 1; + return ret; +} + +static int palmas_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + unsigned char alarm_data[PALMAS_NUM_TIME_REGS]; + struct palmas *palmas = dev_get_drvdata(dev->parent); + int ret; + + ret = palmas_rtc_alarm_irq_enable(dev, 0); + if (ret < 0) { + dev_err(dev, "Disable RTC alarm failed\n"); + return ret; + } + + 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); + + ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, + PALMAS_ALARM_SECONDS_REG, alarm_data, PALMAS_NUM_TIME_REGS); + if (ret < 0) { + dev_err(dev, "ALARM_SECONDS_REG write failed, err = %d\n", ret); + return ret; + } + + if (alm->enabled) + ret = palmas_rtc_alarm_irq_enable(dev, 1); + return ret; +} + +static int palmas_clear_interrupts(struct device *dev) +{ + struct palmas *palmas = dev_get_drvdata(dev->parent); + unsigned int rtc_reg; + int ret; + + ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG, + &rtc_reg); + if (ret < 0) { + dev_err(dev, "RTC_STATUS read failed, err = %d\n", ret); + return ret; + } + + ret = palmas_write(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG, + rtc_reg); + if (ret < 0) { + dev_err(dev, "RTC_STATUS write failed, err = %d\n", ret); + return ret; + } + return 0; +} + +static irqreturn_t palmas_rtc_interrupt(int irq, void *context) +{ + struct palmas_rtc *palmas_rtc = context; + struct device *dev = palmas_rtc->dev; + int ret; + + ret = palmas_clear_interrupts(dev); + if (ret < 0) { + dev_err(dev, "RTC interrupt clear failed, err = %d\n", ret); + return IRQ_NONE; + } + + rtc_update_irq(palmas_rtc->rtc, 1, RTC_IRQF | RTC_AF); + return IRQ_HANDLED; +} + +static const struct rtc_class_ops palmas_rtc_ops = { + .read_time = palmas_rtc_read_time, + .set_time = palmas_rtc_set_time, + .read_alarm = palmas_rtc_read_alarm, + .set_alarm = palmas_rtc_set_alarm, + .alarm_irq_enable = palmas_rtc_alarm_irq_enable, +}; + +static int palmas_rtc_probe(struct platform_device *pdev) +{ + struct palmas *palmas = dev_get_drvdata(pdev->dev.parent); + struct palmas_rtc *palmas_rtc = NULL; + int ret; + bool enable_bb_charging = false; + bool high_bb_charging = false; + + if (pdev->dev.of_node) { + enable_bb_charging = of_property_read_bool(pdev->dev.of_node, + "ti,backup-battery-chargeable"); + high_bb_charging = of_property_read_bool(pdev->dev.of_node, + "ti,backup-battery-charge-high-current"); + } + + palmas_rtc = devm_kzalloc(&pdev->dev, sizeof(struct palmas_rtc), + GFP_KERNEL); + if (!palmas_rtc) + return -ENOMEM; + + /* Clear pending interrupts */ + ret = palmas_clear_interrupts(&pdev->dev); + if (ret < 0) { + dev_err(&pdev->dev, "clear RTC int failed, err = %d\n", ret); + return ret; + } + + palmas_rtc->dev = &pdev->dev; + platform_set_drvdata(pdev, palmas_rtc); + + if (enable_bb_charging) { + unsigned reg = PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG; + + if (high_bb_charging) + reg = 0; + + ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE, + PALMAS_BACKUP_BATTERY_CTRL, + PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG, reg); + if (ret < 0) { + dev_err(&pdev->dev, + "BACKUP_BATTERY_CTRL update failed, %d\n", ret); + return ret; + } + + ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE, + PALMAS_BACKUP_BATTERY_CTRL, + PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN, + PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN); + if (ret < 0) { + dev_err(&pdev->dev, + "BACKUP_BATTERY_CTRL update failed, %d\n", ret); + return ret; + } + } + + /* Start RTC */ + ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG, + PALMAS_RTC_CTRL_REG_STOP_RTC, + PALMAS_RTC_CTRL_REG_STOP_RTC); + if (ret < 0) { + dev_err(&pdev->dev, "RTC_CTRL write failed, err = %d\n", ret); + return ret; + } + + palmas_rtc->irq = platform_get_irq(pdev, 0); + + device_init_wakeup(&pdev->dev, 1); + palmas_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, + &palmas_rtc_ops, THIS_MODULE); + if (IS_ERR(palmas_rtc->rtc)) { + ret = PTR_ERR(palmas_rtc->rtc); + dev_err(&pdev->dev, "RTC register failed, err = %d\n", ret); + return ret; + } + + ret = devm_request_threaded_irq(&pdev->dev, palmas_rtc->irq, NULL, + palmas_rtc_interrupt, + IRQF_TRIGGER_LOW | IRQF_ONESHOT, + dev_name(&pdev->dev), palmas_rtc); + if (ret < 0) { + dev_err(&pdev->dev, "IRQ request failed, err = %d\n", ret); + return ret; + } + + return 0; +} + +static int palmas_rtc_remove(struct platform_device *pdev) +{ + palmas_rtc_alarm_irq_enable(&pdev->dev, 0); + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int palmas_rtc_suspend(struct device *dev) +{ + struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + enable_irq_wake(palmas_rtc->irq); + return 0; +} + +static int palmas_rtc_resume(struct device *dev) +{ + struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + disable_irq_wake(palmas_rtc->irq); + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(palmas_rtc_pm_ops, palmas_rtc_suspend, + palmas_rtc_resume); + +#ifdef CONFIG_OF +static const struct of_device_id of_palmas_rtc_match[] = { + { .compatible = "ti,palmas-rtc"}, + { }, +}; +MODULE_DEVICE_TABLE(of, of_palmas_rtc_match); +#endif + +static struct platform_driver palmas_rtc_driver = { + .probe = palmas_rtc_probe, + .remove = palmas_rtc_remove, + .driver = { + .name = "palmas-rtc", + .pm = &palmas_rtc_pm_ops, + .of_match_table = of_match_ptr(of_palmas_rtc_match), + }, +}; + +module_platform_driver(palmas_rtc_driver); + +MODULE_ALIAS("platform:palmas_rtc"); +MODULE_DESCRIPTION("TI PALMAS series RTC driver"); +MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); +MODULE_LICENSE("GPL v2"); |