--- /dev/null
+/*
+ * drivers/rtc/rtc-pl031.c
+ *
+ * Real Time Clock interface for ARM AMBA PrimeCell 031 RTC
+ *
+ * Author: Deepak Saxena <dsaxena@plexity.net>
+ *
+ * Copyright 2006 (c) MontaVista Software, Inc.
+ *
+ * Author: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
+ * Copyright 2010 (c) ST-Ericsson AB
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/amba/bus.h>
+#include <linux/io.h>
+#include <linux/bcd.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+
+/*
+ * Register definitions
+ */
+#define RTC_DR 0x00 /* Data read register */
+#define RTC_MR 0x04 /* Match register */
+#define RTC_LR 0x08 /* Data load register */
+#define RTC_CR 0x0c /* Control register */
+#define RTC_IMSC 0x10 /* Interrupt mask and set register */
+#define RTC_RIS 0x14 /* Raw interrupt status register */
+#define RTC_MIS 0x18 /* Masked interrupt status register */
+#define RTC_ICR 0x1c /* Interrupt clear register */
+/* ST variants have additional timer functionality */
+#define RTC_TDR 0x20 /* Timer data read register */
+#define RTC_TLR 0x24 /* Timer data load register */
+#define RTC_TCR 0x28 /* Timer control register */
+#define RTC_YDR 0x30 /* Year data read register */
+#define RTC_YMR 0x34 /* Year match register */
+#define RTC_YLR 0x38 /* Year data load register */
+
+#define RTC_CR_EN (1 << 0) /* counter enable bit */
+#define RTC_CR_CWEN (1 << 26) /* Clockwatch enable bit */
+
+#define RTC_TCR_EN (1 << 1) /* Periodic timer enable bit */
+
+/* Common bit definitions for Interrupt status and control registers */
+#define RTC_BIT_AI (1 << 0) /* Alarm interrupt bit */
+#define RTC_BIT_PI (1 << 1) /* Periodic interrupt bit. ST variants only. */
+
+/* Common bit definations for ST v2 for reading/writing time */
+#define RTC_SEC_SHIFT 0
+#define RTC_SEC_MASK (0x3F << RTC_SEC_SHIFT) /* Second [0-59] */
+#define RTC_MIN_SHIFT 6
+#define RTC_MIN_MASK (0x3F << RTC_MIN_SHIFT) /* Minute [0-59] */
+#define RTC_HOUR_SHIFT 12
+#define RTC_HOUR_MASK (0x1F << RTC_HOUR_SHIFT) /* Hour [0-23] */
+#define RTC_WDAY_SHIFT 17
+#define RTC_WDAY_MASK (0x7 << RTC_WDAY_SHIFT) /* Day of Week [1-7] 1=Sunday */
+#define RTC_MDAY_SHIFT 20
+#define RTC_MDAY_MASK (0x1F << RTC_MDAY_SHIFT) /* Day of Month [1-31] */
+#define RTC_MON_SHIFT 25
+#define RTC_MON_MASK (0xF << RTC_MON_SHIFT) /* Month [1-12] 1=January */
+
+#define RTC_TIMER_FREQ 32768
+
+/**
+ * struct pl031_vendor_data - per-vendor variations
+ * @ops: the vendor-specific operations used on this silicon version
+ * @clockwatch: if this is an ST Microelectronics silicon version with a
+ * clockwatch function
+ * @st_weekday: if this is an ST Microelectronics silicon version that need
+ * the weekday fix
+ * @irqflags: special IRQ flags per variant
+ */
+struct pl031_vendor_data {
+ struct rtc_class_ops ops;
+ bool clockwatch;
+ bool st_weekday;
+ unsigned long irqflags;
+};
+
+struct pl031_local {
+ struct pl031_vendor_data *vendor;
+ struct rtc_device *rtc;
+ void __iomem *base;
+};
+
+static int pl031_alarm_irq_enable(struct device *dev,
+ unsigned int enabled)
+{
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+ unsigned long imsc;
+
+ /* Clear any pending alarm interrupts. */
+ writel(RTC_BIT_AI, ldata->base + RTC_ICR);
+
+ imsc = readl(ldata->base + RTC_IMSC);
+
+ if (enabled == 1)
+ writel(imsc | RTC_BIT_AI, ldata->base + RTC_IMSC);
+ else
+ writel(imsc & ~RTC_BIT_AI, ldata->base + RTC_IMSC);
+
+ return 0;
+}
+
+/*
+ * Convert Gregorian date to ST v2 RTC format.
+ */
+static int pl031_stv2_tm_to_time(struct device *dev,
+ struct rtc_time *tm, unsigned long *st_time,
+ unsigned long *bcd_year)
+{
+ int year = tm->tm_year + 1900;
+ int wday = tm->tm_wday;
+
+ /* wday masking is not working in hardware so wday must be valid */
+ if (wday < -1 || wday > 6) {
+ dev_err(dev, "invalid wday value %d\n", tm->tm_wday);
+ return -EINVAL;
+ } else if (wday == -1) {
+ /* wday is not provided, calculate it here */
+ unsigned long time;
+ struct rtc_time calc_tm;
+
+ rtc_tm_to_time(tm, &time);
+ rtc_time_to_tm(time, &calc_tm);
+ wday = calc_tm.tm_wday;
+ }
+
+ *bcd_year = (bin2bcd(year % 100) | bin2bcd(year / 100) << 8);
+
+ *st_time = ((tm->tm_mon + 1) << RTC_MON_SHIFT)
+ | (tm->tm_mday << RTC_MDAY_SHIFT)
+ | ((wday + 1) << RTC_WDAY_SHIFT)
+ | (tm->tm_hour << RTC_HOUR_SHIFT)
+ | (tm->tm_min << RTC_MIN_SHIFT)
+ | (tm->tm_sec << RTC_SEC_SHIFT);
+
+ return 0;
+}
+
+/*
+ * Convert ST v2 RTC format to Gregorian date.
+ */
+static int pl031_stv2_time_to_tm(unsigned long st_time, unsigned long bcd_year,
+ struct rtc_time *tm)
+{
+ tm->tm_year = bcd2bin(bcd_year) + (bcd2bin(bcd_year >> 8) * 100);
+ tm->tm_mon = ((st_time & RTC_MON_MASK) >> RTC_MON_SHIFT) - 1;
+ tm->tm_mday = ((st_time & RTC_MDAY_MASK) >> RTC_MDAY_SHIFT);
+ tm->tm_wday = ((st_time & RTC_WDAY_MASK) >> RTC_WDAY_SHIFT) - 1;
+ tm->tm_hour = ((st_time & RTC_HOUR_MASK) >> RTC_HOUR_SHIFT);
+ tm->tm_min = ((st_time & RTC_MIN_MASK) >> RTC_MIN_SHIFT);
+ tm->tm_sec = ((st_time & RTC_SEC_MASK) >> RTC_SEC_SHIFT);
+
+ tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
+ tm->tm_year -= 1900;
+
+ return 0;
+}
+
+static int pl031_stv2_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+
+ pl031_stv2_time_to_tm(readl(ldata->base + RTC_DR),
+ readl(ldata->base + RTC_YDR), tm);
+
+ return 0;
+}
+
+static int pl031_stv2_set_time(struct device *dev, struct rtc_time *tm)
+{
+ unsigned long time;
+ unsigned long bcd_year;
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+ int ret;
+
+ ret = pl031_stv2_tm_to_time(dev, tm, &time, &bcd_year);
+ if (ret == 0) {
+ writel(bcd_year, ldata->base + RTC_YLR);
+ writel(time, ldata->base + RTC_LR);
+ }
+
+ return ret;
+}
+
+static int pl031_stv2_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+ int ret;
+
+ ret = pl031_stv2_time_to_tm(readl(ldata->base + RTC_MR),
+ readl(ldata->base + RTC_YMR), &alarm->time);
+
+ alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI;
+ alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI;
+
+ return ret;
+}
+
+static int pl031_stv2_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+ unsigned long time;
+ unsigned long bcd_year;
+ int ret;
+
+ /* At the moment, we can only deal with non-wildcarded alarm times. */
+ ret = rtc_valid_tm(&alarm->time);
+ if (ret == 0) {
+ ret = pl031_stv2_tm_to_time(dev, &alarm->time,
+ &time, &bcd_year);
+ if (ret == 0) {
+ writel(bcd_year, ldata->base + RTC_YMR);
+ writel(time, ldata->base + RTC_MR);
+
+ pl031_alarm_irq_enable(dev, alarm->enabled);
+ }
+ }
+
+ return ret;
+}
+
+static irqreturn_t pl031_interrupt(int irq, void *dev_id)
+{
+ struct pl031_local *ldata = dev_id;
+ unsigned long rtcmis;
+ unsigned long events = 0;
+
+ rtcmis = readl(ldata->base + RTC_MIS);
+ if (rtcmis & RTC_BIT_AI) {
+ writel(RTC_BIT_AI, ldata->base + RTC_ICR);
+ events |= (RTC_AF | RTC_IRQF);
+ rtc_update_irq(ldata->rtc, 1, events);
+
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
+}
+
+static int pl031_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+
+ rtc_time_to_tm(readl(ldata->base + RTC_DR), tm);
+
+ return 0;
+}
+
+static int pl031_set_time(struct device *dev, struct rtc_time *tm)
+{
+ unsigned long time;
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+ int ret;
+
+ ret = rtc_tm_to_time(tm, &time);
+
+ if (ret == 0)
+ writel(time, ldata->base + RTC_LR);
+
+ return ret;
+}
+
+static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+
+ rtc_time_to_tm(readl(ldata->base + RTC_MR), &alarm->time);
+
+ alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI;
+ alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI;
+
+ return 0;
+}
+
+static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ struct pl031_local *ldata = dev_get_drvdata(dev);
+ unsigned long time;
+ int ret;
+
+ /* At the moment, we can only deal with non-wildcarded alarm times. */
+ ret = rtc_valid_tm(&alarm->time);
+ if (ret == 0) {
+ ret = rtc_tm_to_time(&alarm->time, &time);
+ if (ret == 0) {
+ writel(time, ldata->base + RTC_MR);
+ pl031_alarm_irq_enable(dev, alarm->enabled);
+ }
+ }
+
+ return ret;
+}
+
+static int pl031_remove(struct amba_device *adev)
+{
+ struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
+
+ free_irq(adev->irq[0], ldata);
+ rtc_device_unregister(ldata->rtc);
+ iounmap(ldata->base);
+ kfree(ldata);
+ amba_release_regions(adev);
+
+ return 0;
+}
+
+static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
+{
+ int ret;
+ struct pl031_local *ldata;
+ struct pl031_vendor_data *vendor = id->data;
+ struct rtc_class_ops *ops = &vendor->ops;
+ unsigned long time, data;
+
+ ret = amba_request_regions(adev, NULL);
+ if (ret)
+ goto err_req;
+
+ ldata = kzalloc(sizeof(struct pl031_local), GFP_KERNEL);
+ if (!ldata) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ ldata->vendor = vendor;
+
+ ldata->base = ioremap(adev->res.start, resource_size(&adev->res));
+
+ if (!ldata->base) {
+ ret = -ENOMEM;
+ goto out_no_remap;
+ }
+
+ amba_set_drvdata(adev, ldata);
+
+ dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev));
+ dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev));
+
+ data = readl(ldata->base + RTC_CR);
+ /* Enable the clockwatch on ST Variants */
+ if (vendor->clockwatch)
+ data |= RTC_CR_CWEN;
+ else
+ data |= RTC_CR_EN;
+ writel(data, ldata->base + RTC_CR);
+
+ /*
+ * On ST PL031 variants, the RTC reset value does not provide correct
+ * weekday for 2000-01-01. Correct the erroneous sunday to saturday.
+ */
+ if (vendor->st_weekday) {
+ if (readl(ldata->base + RTC_YDR) == 0x2000) {
+ time = readl(ldata->base + RTC_DR);
+ if ((time &
+ (RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK))
+ == 0x02120000) {
+ time = time | (0x7 << RTC_WDAY_SHIFT);
+ writel(0x2000, ldata->base + RTC_YLR);
+ writel(time, ldata->base + RTC_LR);
+ }
+ }
+ }
+
+ device_init_wakeup(&adev->dev, 1);
+ ldata->rtc = rtc_device_register("pl031", &adev->dev, ops,
+ THIS_MODULE);
+ if (IS_ERR(ldata->rtc)) {
+ ret = PTR_ERR(ldata->rtc);
+ goto out_no_rtc;
+ }
+
+ if (request_irq(adev->irq[0], pl031_interrupt,
+ vendor->irqflags, "rtc-pl031", ldata)) {
+ ret = -EIO;
+ goto out_no_irq;
+ }
+
+ return 0;
+
+out_no_irq:
+ rtc_device_unregister(ldata->rtc);
+out_no_rtc:
+ iounmap(ldata->base);
+out_no_remap:
+ kfree(ldata);
+out:
+ amba_release_regions(adev);
+err_req:
+
+ return ret;
+}
+
+/* Operations for the original ARM version */
+static struct pl031_vendor_data arm_pl031 = {
+ .ops = {
+ .read_time = pl031_read_time,
+ .set_time = pl031_set_time,
+ .read_alarm = pl031_read_alarm,
+ .set_alarm = pl031_set_alarm,
+ .alarm_irq_enable = pl031_alarm_irq_enable,
+ },
+ .irqflags = IRQF_NO_SUSPEND,
+};
+
+/* The First ST derivative */
+static struct pl031_vendor_data stv1_pl031 = {
+ .ops = {
+ .read_time = pl031_read_time,
+ .set_time = pl031_set_time,
+ .read_alarm = pl031_read_alarm,
+ .set_alarm = pl031_set_alarm,
+ .alarm_irq_enable = pl031_alarm_irq_enable,
+ },
+ .clockwatch = true,
+ .st_weekday = true,
+ .irqflags = IRQF_NO_SUSPEND,
+};
+
+/* And the second ST derivative */
+static struct pl031_vendor_data stv2_pl031 = {
+ .ops = {
+ .read_time = pl031_stv2_read_time,
+ .set_time = pl031_stv2_set_time,
+ .read_alarm = pl031_stv2_read_alarm,
+ .set_alarm = pl031_stv2_set_alarm,
+ .alarm_irq_enable = pl031_alarm_irq_enable,
+ },
+ .clockwatch = true,
+ .st_weekday = true,
+ /*
+ * This variant shares the IRQ with another block and must not
+ * suspend that IRQ line.
+ */
+ .irqflags = IRQF_SHARED | IRQF_NO_SUSPEND,
+};
+
+static struct amba_id pl031_ids[] = {
+ {
+ .id = 0x00041031,
+ .mask = 0x000fffff,
+ .data = &arm_pl031,
+ },
+ /* ST Micro variants */
+ {
+ .id = 0x00180031,
+ .mask = 0x00ffffff,
+ .data = &stv1_pl031,
+ },
+ {
+ .id = 0x00280031,
+ .mask = 0x00ffffff,
+ .data = &stv2_pl031,
+ },
+ {0, 0},
+};
+
+MODULE_DEVICE_TABLE(amba, pl031_ids);
+
+static struct amba_driver pl031_driver = {
+ .drv = {
+ .name = "rtc-pl031",
+ },
+ .id_table = pl031_ids,
+ .probe = pl031_probe,
+ .remove = pl031_remove,
+};
+
+module_amba_driver(pl031_driver);
+
+MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net");
+MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff