Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 474 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-pcf2123.c b/drivers/rtc/rtc-pcf2123.c
new file mode 100644
index 000000000..e5222c5d8
--- /dev/null
+++ b/drivers/rtc/rtc-pcf2123.c
@@ -0,0 +1,474 @@
+/*
+ * 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.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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/sysfs.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_ENABLE		BIT(7)	/* MN, HR, DM, or DW alarm enable */
+
+/* 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 */
+
+/* READ/WRITE ADDRESS BITS */
+#define PCF2123_WRITE		BIT(4)
+#define PCF2123_READ		(BIT(4) | BIT(7))
+
+
+static struct spi_driver pcf2123_driver;
+
+struct pcf2123_sysfs_reg {
+	struct device_attribute attr;
+	char name[2];
+};
+
+struct pcf2123_plat_data {
+	struct rtc_device *rtc;
+	struct pcf2123_sysfs_reg regs[16];
+};
+
+/*
+ * Causes a 30 nanosecond delay to ensure that the PCF2123 chip select
+ * is released properly after an SPI write.  This function should be
+ * called after EVERY read/write call over SPI.
+ */
+static inline void pcf2123_delay_trec(void)
+{
+	ndelay(30);
+}
+
+static int pcf2123_read(struct device *dev, u8 reg, u8 *rxbuf, size_t size)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	int ret;
+
+	reg |= PCF2123_READ;
+	ret = spi_write_then_read(spi, &reg, 1, rxbuf, size);
+	pcf2123_delay_trec();
+
+	return ret;
+}
+
+static int pcf2123_write(struct device *dev, u8 *txbuf, size_t size)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	int ret;
+
+	txbuf[0] |= PCF2123_WRITE;
+	ret = spi_write(spi, txbuf, size);
+	pcf2123_delay_trec();
+
+	return ret;
+}
+
+static int pcf2123_write_reg(struct device *dev, u8 reg, u8 val)
+{
+	u8 txbuf[2];
+
+	txbuf[0] = reg;
+	txbuf[1] = val;
+	return pcf2123_write(dev, txbuf, sizeof(txbuf));
+}
+
+static ssize_t pcf2123_show(struct device *dev, struct device_attribute *attr,
+			    char *buffer)
+{
+	struct pcf2123_sysfs_reg *r;
+	u8 rxbuf[1];
+	unsigned long reg;
+	int ret;
+
+	r = container_of(attr, struct pcf2123_sysfs_reg, attr);
+
+	ret = kstrtoul(r->name, 16, &reg);
+	if (ret)
+		return ret;
+
+	ret = pcf2123_read(dev, reg, rxbuf, 1);
+	if (ret < 0)
+		return -EIO;
+
+	return sprintf(buffer, "0x%x\n", rxbuf[0]);
+}
+
+static ssize_t pcf2123_store(struct device *dev, struct device_attribute *attr,
+			     const char *buffer, size_t count)
+{
+	struct pcf2123_sysfs_reg *r;
+	unsigned long reg;
+	unsigned long val;
+
+	int ret;
+
+	r = container_of(attr, struct pcf2123_sysfs_reg, attr);
+
+	ret = kstrtoul(r->name, 16, &reg);
+	if (ret)
+		return ret;
+
+	ret = kstrtoul(buffer, 10, &val);
+	if (ret)
+		return ret;
+
+	ret = pcf2123_write_reg(dev, reg, val);
+	if (ret < 0)
+		return -EIO;
+	return count;
+}
+
+static int pcf2123_read_offset(struct device *dev, long *offset)
+{
+	int ret;
+	s8 reg;
+
+	ret = pcf2123_read(dev, PCF2123_REG_OFFSET, &reg, 1);
+	if (ret < 0)
+		return ret;
+
+	if (reg & OFFSET_COARSE)
+		reg <<= 1; /* multiply by 2 and sign extend */
+	else
+		reg = sign_extend32(reg, OFFSET_SIGN_BIT);
+
+	*offset = ((long)reg) * 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)
+{
+	s8 reg;
+
+	if (offset > OFFSET_STEP * 127)
+		reg = 127;
+	else if (offset < OFFSET_STEP * -128)
+		reg = -128;
+	else
+		reg = (s8)((offset + (OFFSET_STEP >> 1)) / 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 pcf2123_write_reg(dev, PCF2123_REG_OFFSET, reg);
+}
+
+static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	u8 rxbuf[7];
+	int ret;
+
+	ret = pcf2123_read(dev, PCF2123_REG_SC, rxbuf, sizeof(rxbuf));
+	if (ret < 0)
+		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]);
+	if (tm->tm_year < 70)
+		tm->tm_year += 100;	/* assume we are in 1970...2069 */
+
+	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
+			"mday=%d, mon=%d, year=%d, wday=%d\n",
+			__func__,
+			tm->tm_sec, tm->tm_min, tm->tm_hour,
+			tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
+
+	return 0;
+}
+
+static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	u8 txbuf[8];
+	int ret;
+
+	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
+			"mday=%d, mon=%d, year=%d, wday=%d\n",
+			__func__,
+			tm->tm_sec, tm->tm_min, tm->tm_hour,
+			tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
+
+	/* Stop the counter first */
+	ret = pcf2123_write_reg(dev, PCF2123_REG_CTRL1, CTRL1_STOP);
+	if (ret < 0)
+		return ret;
+
+	/* Set the new time */
+	txbuf[0] = PCF2123_REG_SC;
+	txbuf[1] = bin2bcd(tm->tm_sec & 0x7F);
+	txbuf[2] = bin2bcd(tm->tm_min & 0x7F);
+	txbuf[3] = bin2bcd(tm->tm_hour & 0x3F);
+	txbuf[4] = bin2bcd(tm->tm_mday & 0x3F);
+	txbuf[5] = tm->tm_wday & 0x07;
+	txbuf[6] = bin2bcd((tm->tm_mon + 1) & 0x1F); /* rtc mn 1-12 */
+	txbuf[7] = bin2bcd(tm->tm_year < 100 ? tm->tm_year : tm->tm_year - 100);
+
+	ret = pcf2123_write(dev, txbuf, sizeof(txbuf));
+	if (ret < 0)
+		return ret;
+
+	/* Start the counter */
+	ret = pcf2123_write_reg(dev, PCF2123_REG_CTRL1, CTRL1_CLEAR);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int pcf2123_reset(struct device *dev)
+{
+	int ret;
+	u8  rxbuf[2];
+
+	ret = pcf2123_write_reg(dev, PCF2123_REG_CTRL1, CTRL1_SW_RESET);
+	if (ret < 0)
+		return ret;
+
+	/* Stop the counter */
+	dev_dbg(dev, "stopping RTC\n");
+	ret = pcf2123_write_reg(dev, PCF2123_REG_CTRL1, CTRL1_STOP);
+	if (ret < 0)
+		return ret;
+
+	/* See if the counter was actually stopped */
+	dev_dbg(dev, "checking for presence of RTC\n");
+	ret = pcf2123_read(dev, PCF2123_REG_CTRL1, rxbuf, sizeof(rxbuf));
+	if (ret < 0)
+		return ret;
+
+	dev_dbg(dev, "received data from RTC (0x%02X 0x%02X)\n",
+		rxbuf[0], rxbuf[1]);
+	if (!(rxbuf[0] & CTRL1_STOP))
+		return -ENODEV;
+
+	/* Start the counter */
+	ret = pcf2123_write_reg(dev, PCF2123_REG_CTRL1, CTRL1_CLEAR);
+	if (ret < 0)
+		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,
+
+};
+
+static int pcf2123_probe(struct spi_device *spi)
+{
+	struct rtc_device *rtc;
+	struct rtc_time tm;
+	struct pcf2123_plat_data *pdata;
+	int ret, i;
+
+	pdata = devm_kzalloc(&spi->dev, sizeof(struct pcf2123_plat_data),
+				GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+	spi->dev.platform_data = pdata;
+
+	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");
+			goto kfree_exit;
+		}
+	}
+
+	dev_info(&spi->dev, "spiclk %u KHz.\n",
+			(spi->max_speed_hz + 500) / 1000);
+
+	/* Finalize the initialization */
+	rtc = devm_rtc_device_register(&spi->dev, pcf2123_driver.driver.name,
+			&pcf2123_rtc_ops, THIS_MODULE);
+
+	if (IS_ERR(rtc)) {
+		dev_err(&spi->dev, "failed to register.\n");
+		ret = PTR_ERR(rtc);
+		goto kfree_exit;
+	}
+
+	pdata->rtc = rtc;
+
+	for (i = 0; i < 16; i++) {
+		sysfs_attr_init(&pdata->regs[i].attr.attr);
+		sprintf(pdata->regs[i].name, "%1x", i);
+		pdata->regs[i].attr.attr.mode = S_IRUGO | S_IWUSR;
+		pdata->regs[i].attr.attr.name = pdata->regs[i].name;
+		pdata->regs[i].attr.show = pcf2123_show;
+		pdata->regs[i].attr.store = pcf2123_store;
+		ret = device_create_file(&spi->dev, &pdata->regs[i].attr);
+		if (ret) {
+			dev_err(&spi->dev, "Unable to create sysfs %s\n",
+				pdata->regs[i].name);
+			goto sysfs_exit;
+		}
+	}
+
+	return 0;
+
+sysfs_exit:
+	for (i--; i >= 0; i--)
+		device_remove_file(&spi->dev, &pdata->regs[i].attr);
+
+kfree_exit:
+	spi->dev.platform_data = NULL;
+	return ret;
+}
+
+static int pcf2123_remove(struct spi_device *spi)
+{
+	struct pcf2123_plat_data *pdata = dev_get_platdata(&spi->dev);
+	int i;
+
+	if (pdata) {
+		for (i = 0; i < 16; i++)
+			if (pdata->regs[i].name[0])
+				device_remove_file(&spi->dev,
+						   &pdata->regs[i].attr);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id pcf2123_dt_ids[] = {
+	{ .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,
+	.remove	= pcf2123_remove,
+};
+
+module_spi_driver(pcf2123_driver);
+
+MODULE_AUTHOR("Chris Verges <chrisv@cyberswitching.com>");
+MODULE_DESCRIPTION("NXP PCF2123 RTC driver");
+MODULE_LICENSE("GPL");