diff options
Diffstat (limited to 'drivers/rtc/rtc-mrst.c')
| -rw-r--r-- | drivers/rtc/rtc-mrst.c | 521 |
1 files changed, 0 insertions, 521 deletions
diff --git a/drivers/rtc/rtc-mrst.c b/drivers/rtc/rtc-mrst.c deleted file mode 100644 index 421b3b6071b6..000000000000 --- a/drivers/rtc/rtc-mrst.c +++ /dev/null @@ -1,521 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * rtc-mrst.c: Driver for Moorestown virtual RTC - * - * (C) Copyright 2009 Intel Corporation - * Author: Jacob Pan (jacob.jun.pan@intel.com) - * Feng Tang (feng.tang@intel.com) - * - * Note: - * VRTC is emulated by system controller firmware, the real HW - * RTC is located in the PMIC device. SCU FW shadows PMIC RTC - * in a memory mapped IO space that is visible to the host IA - * processor. - * - * This driver is based upon drivers/rtc/rtc-cmos.c - */ - -/* - * Note: - * * vRTC only supports binary mode and 24H mode - * * vRTC only support PIE and AIE, no UIE, and its PIE only happens - * at 23:59:59pm everyday, no support for adjustable frequency - * * Alarm function is also limited to hr/min/sec. - */ - -#include <linux/mod_devicetable.h> -#include <linux/platform_device.h> -#include <linux/interrupt.h> -#include <linux/spinlock.h> -#include <linux/kernel.h> -#include <linux/mc146818rtc.h> -#include <linux/module.h> -#include <linux/init.h> -#include <linux/sfi.h> - -#include <asm/intel_scu_ipc.h> -#include <asm/intel-mid.h> -#include <asm/intel_mid_vrtc.h> - -struct mrst_rtc { - struct rtc_device *rtc; - struct device *dev; - int irq; - - u8 enabled_wake; - u8 suspend_ctrl; -}; - -static const char driver_name[] = "rtc_mrst"; - -#define RTC_IRQMASK (RTC_PF | RTC_AF) - -static inline int is_intr(u8 rtc_intr) -{ - if (!(rtc_intr & RTC_IRQF)) - return 0; - return rtc_intr & RTC_IRQMASK; -} - -static inline unsigned char vrtc_is_updating(void) -{ - unsigned char uip; - unsigned long flags; - - spin_lock_irqsave(&rtc_lock, flags); - uip = (vrtc_cmos_read(RTC_FREQ_SELECT) & RTC_UIP); - spin_unlock_irqrestore(&rtc_lock, flags); - return uip; -} - -/* - * rtc_time's year contains the increment over 1900, but vRTC's YEAR - * register can't be programmed to value larger than 0x64, so vRTC - * driver chose to use 1972 (1970 is UNIX time start point) as the base, - * and does the translation at read/write time. - * - * Why not just use 1970 as the offset? it's because using 1972 will - * make it consistent in leap year setting for both vrtc and low-level - * physical rtc devices. Then why not use 1960 as the offset? If we use - * 1960, for a device's first use, its YEAR register is 0 and the system - * year will be parsed as 1960 which is not a valid UNIX time and will - * cause many applications to fail mysteriously. - */ -static int mrst_read_time(struct device *dev, struct rtc_time *time) -{ - unsigned long flags; - - if (vrtc_is_updating()) - msleep(20); - - spin_lock_irqsave(&rtc_lock, flags); - time->tm_sec = vrtc_cmos_read(RTC_SECONDS); - time->tm_min = vrtc_cmos_read(RTC_MINUTES); - time->tm_hour = vrtc_cmos_read(RTC_HOURS); - time->tm_mday = vrtc_cmos_read(RTC_DAY_OF_MONTH); - time->tm_mon = vrtc_cmos_read(RTC_MONTH); - time->tm_year = vrtc_cmos_read(RTC_YEAR); - spin_unlock_irqrestore(&rtc_lock, flags); - - /* Adjust for the 1972/1900 */ - time->tm_year += 72; - time->tm_mon--; - return 0; -} - -static int mrst_set_time(struct device *dev, struct rtc_time *time) -{ - int ret; - unsigned long flags; - unsigned char mon, day, hrs, min, sec; - unsigned int yrs; - - yrs = time->tm_year; - mon = time->tm_mon + 1; /* tm_mon starts at zero */ - day = time->tm_mday; - hrs = time->tm_hour; - min = time->tm_min; - sec = time->tm_sec; - - if (yrs < 72 || yrs > 172) - return -EINVAL; - yrs -= 72; - - spin_lock_irqsave(&rtc_lock, flags); - - vrtc_cmos_write(yrs, RTC_YEAR); - vrtc_cmos_write(mon, RTC_MONTH); - vrtc_cmos_write(day, RTC_DAY_OF_MONTH); - vrtc_cmos_write(hrs, RTC_HOURS); - vrtc_cmos_write(min, RTC_MINUTES); - vrtc_cmos_write(sec, RTC_SECONDS); - - spin_unlock_irqrestore(&rtc_lock, flags); - - ret = intel_scu_ipc_simple_command(IPCMSG_VRTC, IPC_CMD_VRTC_SETTIME); - return ret; -} - -static int mrst_read_alarm(struct device *dev, struct rtc_wkalrm *t) -{ - struct mrst_rtc *mrst = dev_get_drvdata(dev); - unsigned char rtc_control; - - if (mrst->irq <= 0) - return -EIO; - - /* vRTC only supports binary mode */ - spin_lock_irq(&rtc_lock); - t->time.tm_sec = vrtc_cmos_read(RTC_SECONDS_ALARM); - t->time.tm_min = vrtc_cmos_read(RTC_MINUTES_ALARM); - t->time.tm_hour = vrtc_cmos_read(RTC_HOURS_ALARM); - - rtc_control = vrtc_cmos_read(RTC_CONTROL); - spin_unlock_irq(&rtc_lock); - - t->enabled = !!(rtc_control & RTC_AIE); - t->pending = 0; - - return 0; -} - -static void mrst_checkintr(struct mrst_rtc *mrst, unsigned char rtc_control) -{ - unsigned char rtc_intr; - - /* - * NOTE after changing RTC_xIE bits we always read INTR_FLAGS; - * allegedly some older rtcs need that to handle irqs properly - */ - rtc_intr = vrtc_cmos_read(RTC_INTR_FLAGS); - rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF; - if (is_intr(rtc_intr)) - rtc_update_irq(mrst->rtc, 1, rtc_intr); -} - -static void mrst_irq_enable(struct mrst_rtc *mrst, unsigned char mask) -{ - unsigned char rtc_control; - - /* - * Flush any pending IRQ status, notably for update irqs, - * before we enable new IRQs - */ - rtc_control = vrtc_cmos_read(RTC_CONTROL); - mrst_checkintr(mrst, rtc_control); - - rtc_control |= mask; - vrtc_cmos_write(rtc_control, RTC_CONTROL); - - mrst_checkintr(mrst, rtc_control); -} - -static void mrst_irq_disable(struct mrst_rtc *mrst, unsigned char mask) -{ - unsigned char rtc_control; - - rtc_control = vrtc_cmos_read(RTC_CONTROL); - rtc_control &= ~mask; - vrtc_cmos_write(rtc_control, RTC_CONTROL); - mrst_checkintr(mrst, rtc_control); -} - -static int mrst_set_alarm(struct device *dev, struct rtc_wkalrm *t) -{ - struct mrst_rtc *mrst = dev_get_drvdata(dev); - unsigned char hrs, min, sec; - int ret = 0; - - if (!mrst->irq) - return -EIO; - - hrs = t->time.tm_hour; - min = t->time.tm_min; - sec = t->time.tm_sec; - - spin_lock_irq(&rtc_lock); - /* Next rtc irq must not be from previous alarm setting */ - mrst_irq_disable(mrst, RTC_AIE); - - /* Update alarm */ - vrtc_cmos_write(hrs, RTC_HOURS_ALARM); - vrtc_cmos_write(min, RTC_MINUTES_ALARM); - vrtc_cmos_write(sec, RTC_SECONDS_ALARM); - - spin_unlock_irq(&rtc_lock); - - ret = intel_scu_ipc_simple_command(IPCMSG_VRTC, IPC_CMD_VRTC_SETALARM); - if (ret) - return ret; - - spin_lock_irq(&rtc_lock); - if (t->enabled) - mrst_irq_enable(mrst, RTC_AIE); - - spin_unlock_irq(&rtc_lock); - - return 0; -} - -/* Currently, the vRTC doesn't support UIE ON/OFF */ -static int mrst_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) -{ - struct mrst_rtc *mrst = dev_get_drvdata(dev); - unsigned long flags; - - spin_lock_irqsave(&rtc_lock, flags); - if (enabled) - mrst_irq_enable(mrst, RTC_AIE); - else - mrst_irq_disable(mrst, RTC_AIE); - spin_unlock_irqrestore(&rtc_lock, flags); - return 0; -} - - -#if IS_ENABLED(CONFIG_RTC_INTF_PROC) - -static int mrst_procfs(struct device *dev, struct seq_file *seq) -{ - unsigned char rtc_control; - - spin_lock_irq(&rtc_lock); - rtc_control = vrtc_cmos_read(RTC_CONTROL); - spin_unlock_irq(&rtc_lock); - - seq_printf(seq, - "periodic_IRQ\t: %s\n" - "alarm\t\t: %s\n" - "BCD\t\t: no\n" - "periodic_freq\t: daily (not adjustable)\n", - (rtc_control & RTC_PIE) ? "on" : "off", - (rtc_control & RTC_AIE) ? "on" : "off"); - - return 0; -} - -#else -#define mrst_procfs NULL -#endif - -static const struct rtc_class_ops mrst_rtc_ops = { - .read_time = mrst_read_time, - .set_time = mrst_set_time, - .read_alarm = mrst_read_alarm, - .set_alarm = mrst_set_alarm, - .proc = mrst_procfs, - .alarm_irq_enable = mrst_rtc_alarm_irq_enable, -}; - -static struct mrst_rtc mrst_rtc; - -/* - * When vRTC IRQ is captured by SCU FW, FW will clear the AIE bit in - * Reg B, so no need for this driver to clear it - */ -static irqreturn_t mrst_rtc_irq(int irq, void *p) -{ - u8 irqstat; - - spin_lock(&rtc_lock); - /* This read will clear all IRQ flags inside Reg C */ - irqstat = vrtc_cmos_read(RTC_INTR_FLAGS); - spin_unlock(&rtc_lock); - - irqstat &= RTC_IRQMASK | RTC_IRQF; - if (is_intr(irqstat)) { - rtc_update_irq(p, 1, irqstat); - return IRQ_HANDLED; - } - return IRQ_NONE; -} - -static int vrtc_mrst_do_probe(struct device *dev, struct resource *iomem, - int rtc_irq) -{ - int retval = 0; - unsigned char rtc_control; - - /* There can be only one ... */ - if (mrst_rtc.dev) - return -EBUSY; - - if (!iomem) - return -ENODEV; - - iomem = devm_request_mem_region(dev, iomem->start, resource_size(iomem), - driver_name); - if (!iomem) { - dev_dbg(dev, "i/o mem already in use.\n"); - return -EBUSY; - } - - mrst_rtc.irq = rtc_irq; - mrst_rtc.dev = dev; - dev_set_drvdata(dev, &mrst_rtc); - - mrst_rtc.rtc = devm_rtc_allocate_device(dev); - if (IS_ERR(mrst_rtc.rtc)) - return PTR_ERR(mrst_rtc.rtc); - - mrst_rtc.rtc->ops = &mrst_rtc_ops; - - rename_region(iomem, dev_name(&mrst_rtc.rtc->dev)); - - spin_lock_irq(&rtc_lock); - mrst_irq_disable(&mrst_rtc, RTC_PIE | RTC_AIE); - rtc_control = vrtc_cmos_read(RTC_CONTROL); - spin_unlock_irq(&rtc_lock); - - if (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY))) - dev_dbg(dev, "TODO: support more than 24-hr BCD mode\n"); - - if (rtc_irq) { - retval = devm_request_irq(dev, rtc_irq, mrst_rtc_irq, - 0, dev_name(&mrst_rtc.rtc->dev), - mrst_rtc.rtc); - if (retval < 0) { - dev_dbg(dev, "IRQ %d is already in use, err %d\n", - rtc_irq, retval); - goto cleanup0; - } - } - - retval = devm_rtc_register_device(mrst_rtc.rtc); - if (retval) - goto cleanup0; - - dev_dbg(dev, "initialised\n"); - return 0; - -cleanup0: - mrst_rtc.dev = NULL; - dev_err(dev, "rtc-mrst: unable to initialise\n"); - return retval; -} - -static void rtc_mrst_do_shutdown(void) -{ - spin_lock_irq(&rtc_lock); - mrst_irq_disable(&mrst_rtc, RTC_IRQMASK); - spin_unlock_irq(&rtc_lock); -} - -static void rtc_mrst_do_remove(struct device *dev) -{ - struct mrst_rtc *mrst = dev_get_drvdata(dev); - - rtc_mrst_do_shutdown(); - - mrst->rtc = NULL; - mrst->dev = NULL; -} - -#ifdef CONFIG_PM_SLEEP -static int mrst_suspend(struct device *dev) -{ - struct mrst_rtc *mrst = dev_get_drvdata(dev); - unsigned char tmp; - - /* Only the alarm might be a wakeup event source */ - spin_lock_irq(&rtc_lock); - mrst->suspend_ctrl = tmp = vrtc_cmos_read(RTC_CONTROL); - if (tmp & (RTC_PIE | RTC_AIE)) { - unsigned char mask; - - if (device_may_wakeup(dev)) - mask = RTC_IRQMASK & ~RTC_AIE; - else - mask = RTC_IRQMASK; - tmp &= ~mask; - vrtc_cmos_write(tmp, RTC_CONTROL); - - mrst_checkintr(mrst, tmp); - } - spin_unlock_irq(&rtc_lock); - - if (tmp & RTC_AIE) { - mrst->enabled_wake = 1; - enable_irq_wake(mrst->irq); - } - - dev_dbg(&mrst_rtc.rtc->dev, "suspend%s, ctrl %02x\n", - (tmp & RTC_AIE) ? ", alarm may wake" : "", - tmp); - - return 0; -} - -/* - * We want RTC alarms to wake us from the deep power saving state - */ -static inline int mrst_poweroff(struct device *dev) -{ - return mrst_suspend(dev); -} - -static int mrst_resume(struct device *dev) -{ - struct mrst_rtc *mrst = dev_get_drvdata(dev); - unsigned char tmp = mrst->suspend_ctrl; - - /* Re-enable any irqs previously active */ - if (tmp & RTC_IRQMASK) { - unsigned char mask; - - if (mrst->enabled_wake) { - disable_irq_wake(mrst->irq); - mrst->enabled_wake = 0; - } - - spin_lock_irq(&rtc_lock); - do { - vrtc_cmos_write(tmp, RTC_CONTROL); - - mask = vrtc_cmos_read(RTC_INTR_FLAGS); - mask &= (tmp & RTC_IRQMASK) | RTC_IRQF; - if (!is_intr(mask)) - break; - - rtc_update_irq(mrst->rtc, 1, mask); - tmp &= ~RTC_AIE; - } while (mask & RTC_AIE); - spin_unlock_irq(&rtc_lock); - } - - dev_dbg(&mrst_rtc.rtc->dev, "resume, ctrl %02x\n", tmp); - - return 0; -} - -static SIMPLE_DEV_PM_OPS(mrst_pm_ops, mrst_suspend, mrst_resume); -#define MRST_PM_OPS (&mrst_pm_ops) - -#else -#define MRST_PM_OPS NULL - -static inline int mrst_poweroff(struct device *dev) -{ - return -ENOSYS; -} - -#endif - -static int vrtc_mrst_platform_probe(struct platform_device *pdev) -{ - return vrtc_mrst_do_probe(&pdev->dev, - platform_get_resource(pdev, IORESOURCE_MEM, 0), - platform_get_irq(pdev, 0)); -} - -static int vrtc_mrst_platform_remove(struct platform_device *pdev) -{ - rtc_mrst_do_remove(&pdev->dev); - return 0; -} - -static void vrtc_mrst_platform_shutdown(struct platform_device *pdev) -{ - if (system_state == SYSTEM_POWER_OFF && !mrst_poweroff(&pdev->dev)) - return; - - rtc_mrst_do_shutdown(); -} - -MODULE_ALIAS("platform:vrtc_mrst"); - -static struct platform_driver vrtc_mrst_platform_driver = { - .probe = vrtc_mrst_platform_probe, - .remove = vrtc_mrst_platform_remove, - .shutdown = vrtc_mrst_platform_shutdown, - .driver = { - .name = driver_name, - .pm = MRST_PM_OPS, - } -}; - -module_platform_driver(vrtc_mrst_platform_driver); - -MODULE_AUTHOR("Jacob Pan; Feng Tang"); -MODULE_DESCRIPTION("Driver for Moorestown virtual RTC"); -MODULE_LICENSE("GPL"); |