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path: root/drivers/rtc/rtc-bd70528.c
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Diffstat (limited to 'drivers/rtc/rtc-bd70528.c')
-rw-r--r--drivers/rtc/rtc-bd70528.c360
1 files changed, 360 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-bd70528.c b/drivers/rtc/rtc-bd70528.c
new file mode 100644
index 000000000..59b627fc1
--- /dev/null
+++ b/drivers/rtc/rtc-bd70528.c
@@ -0,0 +1,360 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+// Copyright (C) 2018 ROHM Semiconductors
+//
+// RTC driver for ROHM BD71828 and BD71815 PMIC
+
+#include <linux/bcd.h>
+#include <linux/mfd/rohm-bd71815.h>
+#include <linux/mfd/rohm-bd71828.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+
+/*
+ * On BD71828 and BD71815 the ALM0 MASK is 14 bytes after the ALM0
+ * block start
+ */
+#define BD718XX_ALM_EN_OFFSET 14
+
+/*
+ * We read regs RTC_SEC => RTC_YEAR
+ * this struct is ordered according to chip registers.
+ * Keep it u8 only (or packed) to avoid padding issues.
+ */
+struct bd70528_rtc_day {
+ u8 sec;
+ u8 min;
+ u8 hour;
+} __packed;
+
+struct bd70528_rtc_data {
+ struct bd70528_rtc_day time;
+ u8 week;
+ u8 day;
+ u8 month;
+ u8 year;
+} __packed;
+
+struct bd71828_rtc_alm {
+ struct bd70528_rtc_data alm0;
+ struct bd70528_rtc_data alm1;
+ u8 alm_mask;
+ u8 alm1_mask;
+} __packed;
+
+struct bd70528_rtc {
+ struct rohm_regmap_dev *parent;
+ struct regmap *regmap;
+ struct device *dev;
+ u8 reg_time_start;
+ u8 bd718xx_alm_block_start;
+};
+
+static inline void tmday2rtc(struct rtc_time *t, struct bd70528_rtc_day *d)
+{
+ d->sec &= ~BD70528_MASK_RTC_SEC;
+ d->min &= ~BD70528_MASK_RTC_MINUTE;
+ d->hour &= ~BD70528_MASK_RTC_HOUR;
+ d->sec |= bin2bcd(t->tm_sec);
+ d->min |= bin2bcd(t->tm_min);
+ d->hour |= bin2bcd(t->tm_hour);
+}
+
+static inline void tm2rtc(struct rtc_time *t, struct bd70528_rtc_data *r)
+{
+ r->day &= ~BD70528_MASK_RTC_DAY;
+ r->week &= ~BD70528_MASK_RTC_WEEK;
+ r->month &= ~BD70528_MASK_RTC_MONTH;
+ /*
+ * PM and 24H bits are not used by Wake - thus we clear them
+ * here and not in tmday2rtc() which is also used by wake.
+ */
+ r->time.hour &= ~(BD70528_MASK_RTC_HOUR_PM | BD70528_MASK_RTC_HOUR_24H);
+
+ tmday2rtc(t, &r->time);
+ /*
+ * We do always set time in 24H mode.
+ */
+ r->time.hour |= BD70528_MASK_RTC_HOUR_24H;
+ r->day |= bin2bcd(t->tm_mday);
+ r->week |= bin2bcd(t->tm_wday);
+ r->month |= bin2bcd(t->tm_mon + 1);
+ r->year = bin2bcd(t->tm_year - 100);
+}
+
+static inline void rtc2tm(struct bd70528_rtc_data *r, struct rtc_time *t)
+{
+ t->tm_sec = bcd2bin(r->time.sec & BD70528_MASK_RTC_SEC);
+ t->tm_min = bcd2bin(r->time.min & BD70528_MASK_RTC_MINUTE);
+ t->tm_hour = bcd2bin(r->time.hour & BD70528_MASK_RTC_HOUR);
+ /*
+ * If RTC is in 12H mode, then bit BD70528_MASK_RTC_HOUR_PM
+ * is not BCD value but tells whether it is AM or PM
+ */
+ if (!(r->time.hour & BD70528_MASK_RTC_HOUR_24H)) {
+ t->tm_hour %= 12;
+ if (r->time.hour & BD70528_MASK_RTC_HOUR_PM)
+ t->tm_hour += 12;
+ }
+ t->tm_mday = bcd2bin(r->day & BD70528_MASK_RTC_DAY);
+ t->tm_mon = bcd2bin(r->month & BD70528_MASK_RTC_MONTH) - 1;
+ t->tm_year = 100 + bcd2bin(r->year & BD70528_MASK_RTC_YEAR);
+ t->tm_wday = bcd2bin(r->week & BD70528_MASK_RTC_WEEK);
+}
+
+static int bd71828_set_alarm(struct device *dev, struct rtc_wkalrm *a)
+{
+ int ret;
+ struct bd71828_rtc_alm alm;
+ struct bd70528_rtc *r = dev_get_drvdata(dev);
+
+ ret = regmap_bulk_read(r->regmap, r->bd718xx_alm_block_start, &alm,
+ sizeof(alm));
+ if (ret) {
+ dev_err(dev, "Failed to read alarm regs\n");
+ return ret;
+ }
+
+ tm2rtc(&a->time, &alm.alm0);
+
+ if (!a->enabled)
+ alm.alm_mask &= ~BD70528_MASK_ALM_EN;
+ else
+ alm.alm_mask |= BD70528_MASK_ALM_EN;
+
+ ret = regmap_bulk_write(r->regmap, r->bd718xx_alm_block_start, &alm,
+ sizeof(alm));
+ if (ret)
+ dev_err(dev, "Failed to set alarm time\n");
+
+ return ret;
+
+}
+
+static int bd71828_read_alarm(struct device *dev, struct rtc_wkalrm *a)
+{
+ int ret;
+ struct bd71828_rtc_alm alm;
+ struct bd70528_rtc *r = dev_get_drvdata(dev);
+
+ ret = regmap_bulk_read(r->regmap, r->bd718xx_alm_block_start, &alm,
+ sizeof(alm));
+ if (ret) {
+ dev_err(dev, "Failed to read alarm regs\n");
+ return ret;
+ }
+
+ rtc2tm(&alm.alm0, &a->time);
+ a->time.tm_mday = -1;
+ a->time.tm_mon = -1;
+ a->time.tm_year = -1;
+ a->enabled = !!(alm.alm_mask & BD70528_MASK_ALM_EN);
+ a->pending = 0;
+
+ return 0;
+}
+
+static int bd71828_set_time(struct device *dev, struct rtc_time *t)
+{
+ int ret;
+ struct bd70528_rtc_data rtc_data;
+ struct bd70528_rtc *r = dev_get_drvdata(dev);
+
+ ret = regmap_bulk_read(r->regmap, r->reg_time_start, &rtc_data,
+ sizeof(rtc_data));
+ if (ret) {
+ dev_err(dev, "Failed to read RTC time registers\n");
+ return ret;
+ }
+ tm2rtc(t, &rtc_data);
+
+ ret = regmap_bulk_write(r->regmap, r->reg_time_start, &rtc_data,
+ sizeof(rtc_data));
+ if (ret)
+ dev_err(dev, "Failed to set RTC time\n");
+
+ return ret;
+}
+
+static int bd70528_get_time(struct device *dev, struct rtc_time *t)
+{
+ struct bd70528_rtc *r = dev_get_drvdata(dev);
+ struct bd70528_rtc_data rtc_data;
+ int ret;
+
+ /* read the RTC date and time registers all at once */
+ ret = regmap_bulk_read(r->regmap, r->reg_time_start, &rtc_data,
+ sizeof(rtc_data));
+ if (ret) {
+ dev_err(dev, "Failed to read RTC time (err %d)\n", ret);
+ return ret;
+ }
+
+ rtc2tm(&rtc_data, t);
+
+ return 0;
+}
+
+static int bd71828_alm_enable(struct device *dev, unsigned int enabled)
+{
+ int ret;
+ struct bd70528_rtc *r = dev_get_drvdata(dev);
+ unsigned int enableval = BD70528_MASK_ALM_EN;
+
+ if (!enabled)
+ enableval = 0;
+
+ ret = regmap_update_bits(r->regmap, r->bd718xx_alm_block_start +
+ BD718XX_ALM_EN_OFFSET, BD70528_MASK_ALM_EN,
+ enableval);
+ if (ret)
+ dev_err(dev, "Failed to change alarm state\n");
+
+ return ret;
+}
+
+static const struct rtc_class_ops bd71828_rtc_ops = {
+ .read_time = bd70528_get_time,
+ .set_time = bd71828_set_time,
+ .read_alarm = bd71828_read_alarm,
+ .set_alarm = bd71828_set_alarm,
+ .alarm_irq_enable = bd71828_alm_enable,
+};
+
+static irqreturn_t alm_hndlr(int irq, void *data)
+{
+ struct rtc_device *rtc = data;
+
+ rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF | RTC_PF);
+ return IRQ_HANDLED;
+}
+
+static int bd70528_probe(struct platform_device *pdev)
+{
+ struct bd70528_rtc *bd_rtc;
+ const struct rtc_class_ops *rtc_ops;
+ const char *irq_name;
+ int ret;
+ struct rtc_device *rtc;
+ int irq;
+ unsigned int hr;
+ u8 hour_reg;
+ enum rohm_chip_type chip = platform_get_device_id(pdev)->driver_data;
+
+ bd_rtc = devm_kzalloc(&pdev->dev, sizeof(*bd_rtc), GFP_KERNEL);
+ if (!bd_rtc)
+ return -ENOMEM;
+
+ bd_rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ if (!bd_rtc->regmap) {
+ dev_err(&pdev->dev, "No regmap\n");
+ return -EINVAL;
+ }
+
+ bd_rtc->dev = &pdev->dev;
+ rtc_ops = &bd71828_rtc_ops;
+
+ switch (chip) {
+ case ROHM_CHIP_TYPE_BD71815:
+ irq_name = "bd71815-rtc-alm-0";
+ bd_rtc->reg_time_start = BD71815_REG_RTC_START;
+
+ /*
+ * See also BD718XX_ALM_EN_OFFSET:
+ * This works for BD71828 and BD71815 as they have same offset
+ * between ALM0 start and ALM0_MASK. If new ICs are to be
+ * added this requires proper check as ALM0_MASK is not located
+ * at the end of ALM0 block - but after all ALM blocks so if
+ * amount of ALMs differ the offset to enable/disable is likely
+ * to be incorrect and enable/disable must be given as own
+ * reg address here.
+ */
+ bd_rtc->bd718xx_alm_block_start = BD71815_REG_RTC_ALM_START;
+ hour_reg = BD71815_REG_HOUR;
+ break;
+ case ROHM_CHIP_TYPE_BD71828:
+ irq_name = "bd71828-rtc-alm-0";
+ bd_rtc->reg_time_start = BD71828_REG_RTC_START;
+ bd_rtc->bd718xx_alm_block_start = BD71828_REG_RTC_ALM_START;
+ hour_reg = BD71828_REG_RTC_HOUR;
+ break;
+ default:
+ dev_err(&pdev->dev, "Unknown chip\n");
+ return -ENOENT;
+ }
+
+ irq = platform_get_irq_byname(pdev, irq_name);
+
+ if (irq < 0)
+ return irq;
+
+ platform_set_drvdata(pdev, bd_rtc);
+
+ ret = regmap_read(bd_rtc->regmap, hour_reg, &hr);
+
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to reag RTC clock\n");
+ return ret;
+ }
+
+ if (!(hr & BD70528_MASK_RTC_HOUR_24H)) {
+ struct rtc_time t;
+
+ ret = rtc_ops->read_time(&pdev->dev, &t);
+
+ if (!ret)
+ ret = rtc_ops->set_time(&pdev->dev, &t);
+
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Setting 24H clock for RTC failed\n");
+ return ret;
+ }
+ }
+
+ device_set_wakeup_capable(&pdev->dev, true);
+ device_wakeup_enable(&pdev->dev);
+
+ rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(rtc)) {
+ dev_err(&pdev->dev, "RTC device creation failed\n");
+ return PTR_ERR(rtc);
+ }
+
+ rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+ rtc->range_max = RTC_TIMESTAMP_END_2099;
+ rtc->ops = rtc_ops;
+
+ /* Request alarm IRQ prior to registerig the RTC */
+ ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, &alm_hndlr,
+ IRQF_ONESHOT, "bd70528-rtc", rtc);
+ if (ret)
+ return ret;
+
+ return devm_rtc_register_device(rtc);
+}
+
+static const struct platform_device_id bd718x7_rtc_id[] = {
+ { "bd71828-rtc", ROHM_CHIP_TYPE_BD71828 },
+ { "bd71815-rtc", ROHM_CHIP_TYPE_BD71815 },
+ { },
+};
+MODULE_DEVICE_TABLE(platform, bd718x7_rtc_id);
+
+static struct platform_driver bd70528_rtc = {
+ .driver = {
+ .name = "bd70528-rtc"
+ },
+ .probe = bd70528_probe,
+ .id_table = bd718x7_rtc_id,
+};
+
+module_platform_driver(bd70528_rtc);
+
+MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
+MODULE_DESCRIPTION("ROHM BD71828 and BD71815 PMIC RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:bd70528-rtc");