Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 467 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-pcf2123.c b/drivers/rtc/rtc-pcf2123.c
new file mode 100644
index 000000000..c3691fa42
--- /dev/null
+++ b/drivers/rtc/rtc-pcf2123.c
@@ -0,0 +1,467 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * An SPI driver for the Philips PCF2123 RTC
+ * Copyright 2009 Cyber Switching, Inc.
+ *
+ * Author: Chris Verges <chrisv@cyberswitching.com>
+ * Maintainers: http://www.cyberswitching.com
+ *
+ * based on the RS5C348 driver in this same directory.
+ *
+ * Thanks to Christian Pellegrin <chripell@fsfe.org> for
+ * the sysfs contributions to this driver.
+ *
+ * Please note that the CS is active high, so platform data
+ * should look something like:
+ *
+ * static struct spi_board_info ek_spi_devices[] = {
+ *	...
+ *	{
+ *		.modalias		= "rtc-pcf2123",
+ *		.chip_select		= 1,
+ *		.controller_data	= (void *)AT91_PIN_PA10,
+ *		.max_speed_hz		= 1000 * 1000,
+ *		.mode			= SPI_CS_HIGH,
+ *		.bus_num		= 0,
+ *	},
+ *	...
+ *};
+ */
+
+#include <linux/bcd.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/rtc.h>
+#include <linux/spi/spi.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+/* REGISTERS */
+#define PCF2123_REG_CTRL1	(0x00)	/* Control Register 1 */
+#define PCF2123_REG_CTRL2	(0x01)	/* Control Register 2 */
+#define PCF2123_REG_SC		(0x02)	/* datetime */
+#define PCF2123_REG_MN		(0x03)
+#define PCF2123_REG_HR		(0x04)
+#define PCF2123_REG_DM		(0x05)
+#define PCF2123_REG_DW		(0x06)
+#define PCF2123_REG_MO		(0x07)
+#define PCF2123_REG_YR		(0x08)
+#define PCF2123_REG_ALRM_MN	(0x09)	/* Alarm Registers */
+#define PCF2123_REG_ALRM_HR	(0x0a)
+#define PCF2123_REG_ALRM_DM	(0x0b)
+#define PCF2123_REG_ALRM_DW	(0x0c)
+#define PCF2123_REG_OFFSET	(0x0d)	/* Clock Rate Offset Register */
+#define PCF2123_REG_TMR_CLKOUT	(0x0e)	/* Timer Registers */
+#define PCF2123_REG_CTDWN_TMR	(0x0f)
+
+/* PCF2123_REG_CTRL1 BITS */
+#define CTRL1_CLEAR		(0)	/* Clear */
+#define CTRL1_CORR_INT		BIT(1)	/* Correction irq enable */
+#define CTRL1_12_HOUR		BIT(2)	/* 12 hour time */
+#define CTRL1_SW_RESET	(BIT(3) | BIT(4) | BIT(6))	/* Software reset */
+#define CTRL1_STOP		BIT(5)	/* Stop the clock */
+#define CTRL1_EXT_TEST		BIT(7)	/* External clock test mode */
+
+/* PCF2123_REG_CTRL2 BITS */
+#define CTRL2_TIE		BIT(0)	/* Countdown timer irq enable */
+#define CTRL2_AIE		BIT(1)	/* Alarm irq enable */
+#define CTRL2_TF		BIT(2)	/* Countdown timer flag */
+#define CTRL2_AF		BIT(3)	/* Alarm flag */
+#define CTRL2_TI_TP		BIT(4)	/* Irq pin generates pulse */
+#define CTRL2_MSF		BIT(5)	/* Minute or second irq flag */
+#define CTRL2_SI		BIT(6)	/* Second irq enable */
+#define CTRL2_MI		BIT(7)	/* Minute irq enable */
+
+/* PCF2123_REG_SC BITS */
+#define OSC_HAS_STOPPED		BIT(7)	/* Clock has been stopped */
+
+/* PCF2123_REG_ALRM_XX BITS */
+#define ALRM_DISABLE		BIT(7)	/* MN, HR, DM, or DW alarm matching */
+
+/* PCF2123_REG_TMR_CLKOUT BITS */
+#define CD_TMR_4096KHZ		(0)	/* 4096 KHz countdown timer */
+#define CD_TMR_64HZ		(1)	/* 64 Hz countdown timer */
+#define CD_TMR_1HZ		(2)	/* 1 Hz countdown timer */
+#define CD_TMR_60th_HZ		(3)	/* 60th Hz countdown timer */
+#define CD_TMR_TE		BIT(3)	/* Countdown timer enable */
+
+/* PCF2123_REG_OFFSET BITS */
+#define OFFSET_SIGN_BIT		6	/* 2's complement sign bit */
+#define OFFSET_COARSE		BIT(7)	/* Coarse mode offset */
+#define OFFSET_STEP		(2170)	/* Offset step in parts per billion */
+#define OFFSET_MASK		GENMASK(6, 0)	/* Offset value */
+
+/* READ/WRITE ADDRESS BITS */
+#define PCF2123_WRITE		BIT(4)
+#define PCF2123_READ		(BIT(4) | BIT(7))
+
+
+static struct spi_driver pcf2123_driver;
+
+struct pcf2123_data {
+	struct rtc_device *rtc;
+	struct regmap *map;
+};
+
+static const struct regmap_config pcf2123_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.read_flag_mask = PCF2123_READ,
+	.write_flag_mask = PCF2123_WRITE,
+	.max_register = PCF2123_REG_CTDWN_TMR,
+};
+
+static int pcf2123_read_offset(struct device *dev, long *offset)
+{
+	struct pcf2123_data *pcf2123 = dev_get_drvdata(dev);
+	int ret, val;
+	unsigned int reg;
+
+	ret = regmap_read(pcf2123->map, PCF2123_REG_OFFSET, &reg);
+	if (ret)
+		return ret;
+
+	val = sign_extend32((reg & OFFSET_MASK), OFFSET_SIGN_BIT);
+
+	if (reg & OFFSET_COARSE)
+		val *= 2;
+
+	*offset = ((long)val) * OFFSET_STEP;
+
+	return 0;
+}
+
+/*
+ * The offset register is a 7 bit signed value with a coarse bit in bit 7.
+ * The main difference between the two is normal offset adjusts the first
+ * second of n minutes every other hour, with 61, 62 and 63 being shoved
+ * into the 60th minute.
+ * The coarse adjustment does the same, but every hour.
+ * the two overlap, with every even normal offset value corresponding
+ * to a coarse offset. Based on this algorithm, it seems that despite the
+ * name, coarse offset is a better fit for overlapping values.
+ */
+static int pcf2123_set_offset(struct device *dev, long offset)
+{
+	struct pcf2123_data *pcf2123 = dev_get_drvdata(dev);
+	s8 reg;
+
+	if (offset > OFFSET_STEP * 127)
+		reg = 127;
+	else if (offset < OFFSET_STEP * -128)
+		reg = -128;
+	else
+		reg = DIV_ROUND_CLOSEST(offset, OFFSET_STEP);
+
+	/* choose fine offset only for odd values in the normal range */
+	if (reg & 1 && reg <= 63 && reg >= -64) {
+		/* Normal offset. Clear the coarse bit */
+		reg &= ~OFFSET_COARSE;
+	} else {
+		/* Coarse offset. Divide by 2 and set the coarse bit */
+		reg >>= 1;
+		reg |= OFFSET_COARSE;
+	}
+
+	return regmap_write(pcf2123->map, PCF2123_REG_OFFSET, (unsigned int)reg);
+}
+
+static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct pcf2123_data *pcf2123 = dev_get_drvdata(dev);
+	u8 rxbuf[7];
+	int ret;
+
+	ret = regmap_bulk_read(pcf2123->map, PCF2123_REG_SC, rxbuf,
+				sizeof(rxbuf));
+	if (ret)
+		return ret;
+
+	if (rxbuf[0] & OSC_HAS_STOPPED) {
+		dev_info(dev, "clock was stopped. Time is not valid\n");
+		return -EINVAL;
+	}
+
+	tm->tm_sec = bcd2bin(rxbuf[0] & 0x7F);
+	tm->tm_min = bcd2bin(rxbuf[1] & 0x7F);
+	tm->tm_hour = bcd2bin(rxbuf[2] & 0x3F); /* rtc hr 0-23 */
+	tm->tm_mday = bcd2bin(rxbuf[3] & 0x3F);
+	tm->tm_wday = rxbuf[4] & 0x07;
+	tm->tm_mon = bcd2bin(rxbuf[5] & 0x1F) - 1; /* rtc mn 1-12 */
+	tm->tm_year = bcd2bin(rxbuf[6]) + 100;
+
+	dev_dbg(dev, "%s: tm is %ptR\n", __func__, tm);
+
+	return 0;
+}
+
+static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct pcf2123_data *pcf2123 = dev_get_drvdata(dev);
+	u8 txbuf[7];
+	int ret;
+
+	dev_dbg(dev, "%s: tm is %ptR\n", __func__, tm);
+
+	/* Stop the counter first */
+	ret = regmap_write(pcf2123->map, PCF2123_REG_CTRL1, CTRL1_STOP);
+	if (ret)
+		return ret;
+
+	/* Set the new time */
+	txbuf[0] = bin2bcd(tm->tm_sec & 0x7F);
+	txbuf[1] = bin2bcd(tm->tm_min & 0x7F);
+	txbuf[2] = bin2bcd(tm->tm_hour & 0x3F);
+	txbuf[3] = bin2bcd(tm->tm_mday & 0x3F);
+	txbuf[4] = tm->tm_wday & 0x07;
+	txbuf[5] = bin2bcd((tm->tm_mon + 1) & 0x1F); /* rtc mn 1-12 */
+	txbuf[6] = bin2bcd(tm->tm_year - 100);
+
+	ret = regmap_bulk_write(pcf2123->map, PCF2123_REG_SC, txbuf,
+				sizeof(txbuf));
+	if (ret)
+		return ret;
+
+	/* Start the counter */
+	ret = regmap_write(pcf2123->map, PCF2123_REG_CTRL1, CTRL1_CLEAR);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int pcf2123_rtc_alarm_irq_enable(struct device *dev, unsigned int en)
+{
+	struct pcf2123_data *pcf2123 = dev_get_drvdata(dev);
+
+	return regmap_update_bits(pcf2123->map, PCF2123_REG_CTRL2, CTRL2_AIE,
+				  en ? CTRL2_AIE : 0);
+}
+
+static int pcf2123_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	struct pcf2123_data *pcf2123 = dev_get_drvdata(dev);
+	u8 rxbuf[4];
+	int ret;
+	unsigned int val = 0;
+
+	ret = regmap_bulk_read(pcf2123->map, PCF2123_REG_ALRM_MN, rxbuf,
+				sizeof(rxbuf));
+	if (ret)
+		return ret;
+
+	alm->time.tm_min = bcd2bin(rxbuf[0] & 0x7F);
+	alm->time.tm_hour = bcd2bin(rxbuf[1] & 0x3F);
+	alm->time.tm_mday = bcd2bin(rxbuf[2] & 0x3F);
+	alm->time.tm_wday = bcd2bin(rxbuf[3] & 0x07);
+
+	dev_dbg(dev, "%s: alm is %ptR\n", __func__, &alm->time);
+
+	ret = regmap_read(pcf2123->map, PCF2123_REG_CTRL2, &val);
+	if (ret)
+		return ret;
+
+	alm->enabled = !!(val & CTRL2_AIE);
+
+	return 0;
+}
+
+static int pcf2123_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	struct pcf2123_data *pcf2123 = dev_get_drvdata(dev);
+	u8 txbuf[4];
+	int ret;
+
+	dev_dbg(dev, "%s: alm is %ptR\n", __func__, &alm->time);
+
+	/* Disable alarm interrupt */
+	ret = regmap_update_bits(pcf2123->map, PCF2123_REG_CTRL2, CTRL2_AIE, 0);
+	if (ret)
+		return ret;
+
+	/* Ensure alarm flag is clear */
+	ret = regmap_update_bits(pcf2123->map, PCF2123_REG_CTRL2, CTRL2_AF, 0);
+	if (ret)
+		return ret;
+
+	/* Set new alarm */
+	txbuf[0] = bin2bcd(alm->time.tm_min & 0x7F);
+	txbuf[1] = bin2bcd(alm->time.tm_hour & 0x3F);
+	txbuf[2] = bin2bcd(alm->time.tm_mday & 0x3F);
+	txbuf[3] = ALRM_DISABLE;
+
+	ret = regmap_bulk_write(pcf2123->map, PCF2123_REG_ALRM_MN, txbuf,
+				sizeof(txbuf));
+	if (ret)
+		return ret;
+
+	return pcf2123_rtc_alarm_irq_enable(dev, alm->enabled);
+}
+
+static irqreturn_t pcf2123_rtc_irq(int irq, void *dev)
+{
+	struct pcf2123_data *pcf2123 = dev_get_drvdata(dev);
+	struct mutex *lock = &pcf2123->rtc->ops_lock;
+	unsigned int val = 0;
+	int ret = IRQ_NONE;
+
+	mutex_lock(lock);
+	regmap_read(pcf2123->map, PCF2123_REG_CTRL2, &val);
+
+	/* Alarm? */
+	if (val & CTRL2_AF) {
+		ret = IRQ_HANDLED;
+
+		/* Clear alarm flag */
+		regmap_update_bits(pcf2123->map, PCF2123_REG_CTRL2, CTRL2_AF, 0);
+
+		rtc_update_irq(pcf2123->rtc, 1, RTC_IRQF | RTC_AF);
+	}
+
+	mutex_unlock(lock);
+
+	return ret;
+}
+
+static int pcf2123_reset(struct device *dev)
+{
+	struct pcf2123_data *pcf2123 = dev_get_drvdata(dev);
+	int ret;
+	unsigned int val = 0;
+
+	ret = regmap_write(pcf2123->map, PCF2123_REG_CTRL1, CTRL1_SW_RESET);
+	if (ret)
+		return ret;
+
+	/* Stop the counter */
+	dev_dbg(dev, "stopping RTC\n");
+	ret = regmap_write(pcf2123->map, PCF2123_REG_CTRL1, CTRL1_STOP);
+	if (ret)
+		return ret;
+
+	/* See if the counter was actually stopped */
+	dev_dbg(dev, "checking for presence of RTC\n");
+	ret = regmap_read(pcf2123->map, PCF2123_REG_CTRL1, &val);
+	if (ret)
+		return ret;
+
+	dev_dbg(dev, "received data from RTC (0x%08X)\n", val);
+	if (!(val & CTRL1_STOP))
+		return -ENODEV;
+
+	/* Start the counter */
+	ret = regmap_write(pcf2123->map, PCF2123_REG_CTRL1, CTRL1_CLEAR);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static const struct rtc_class_ops pcf2123_rtc_ops = {
+	.read_time	= pcf2123_rtc_read_time,
+	.set_time	= pcf2123_rtc_set_time,
+	.read_offset	= pcf2123_read_offset,
+	.set_offset	= pcf2123_set_offset,
+	.read_alarm	= pcf2123_rtc_read_alarm,
+	.set_alarm	= pcf2123_rtc_set_alarm,
+	.alarm_irq_enable = pcf2123_rtc_alarm_irq_enable,
+};
+
+static int pcf2123_probe(struct spi_device *spi)
+{
+	struct rtc_device *rtc;
+	struct rtc_time tm;
+	struct pcf2123_data *pcf2123;
+	int ret = 0;
+
+	pcf2123 = devm_kzalloc(&spi->dev, sizeof(struct pcf2123_data),
+				GFP_KERNEL);
+	if (!pcf2123)
+		return -ENOMEM;
+
+	dev_set_drvdata(&spi->dev, pcf2123);
+
+	pcf2123->map = devm_regmap_init_spi(spi, &pcf2123_regmap_config);
+	if (IS_ERR(pcf2123->map)) {
+		dev_err(&spi->dev, "regmap init failed.\n");
+		return PTR_ERR(pcf2123->map);
+	}
+
+	ret = pcf2123_rtc_read_time(&spi->dev, &tm);
+	if (ret < 0) {
+		ret = pcf2123_reset(&spi->dev);
+		if (ret < 0) {
+			dev_err(&spi->dev, "chip not found\n");
+			return ret;
+		}
+	}
+
+	dev_info(&spi->dev, "spiclk %u KHz.\n",
+			(spi->max_speed_hz + 500) / 1000);
+
+	/* Finalize the initialization */
+	rtc = devm_rtc_allocate_device(&spi->dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	pcf2123->rtc = rtc;
+
+	/* Register alarm irq */
+	if (spi->irq > 0) {
+		ret = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
+				pcf2123_rtc_irq,
+				IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+				pcf2123_driver.driver.name, &spi->dev);
+		if (!ret)
+			device_init_wakeup(&spi->dev, true);
+		else
+			dev_err(&spi->dev, "could not request irq.\n");
+	}
+
+	/* The PCF2123's alarm only has minute accuracy. Must add timer
+	 * support to this driver to generate interrupts more than once
+	 * per minute.
+	 */
+	rtc->uie_unsupported = 1;
+	rtc->ops = &pcf2123_rtc_ops;
+	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rtc->range_max = RTC_TIMESTAMP_END_2099;
+	rtc->set_start_time = true;
+
+	ret = rtc_register_device(rtc);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id pcf2123_dt_ids[] = {
+	{ .compatible = "nxp,pcf2123", },
+	{ .compatible = "microcrystal,rv2123", },
+	/* Deprecated, do not use */
+	{ .compatible = "nxp,rtc-pcf2123", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, pcf2123_dt_ids);
+#endif
+
+static struct spi_driver pcf2123_driver = {
+	.driver	= {
+			.name	= "rtc-pcf2123",
+			.of_match_table = of_match_ptr(pcf2123_dt_ids),
+	},
+	.probe	= pcf2123_probe,
+};
+
+module_spi_driver(pcf2123_driver);
+
+MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>");
+MODULE_DESCRIPTION("NXP PCF2123 RTC driver");
+MODULE_LICENSE("GPL");