1 files changed, 483 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-ds1343.c b/drivers/rtc/rtc-ds1343.c
new file mode 100644
index 000000000..ed5a6ba89
--- /dev/null
+++ b/drivers/rtc/rtc-ds1343.c
@@ -0,0 +1,483 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* rtc-ds1343.c
+ *
+ * Driver for Dallas Semiconductor DS1343 Low Current, SPI Compatible
+ * Real Time Clock
+ *
+ * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
+ *	    Ankur Srivastava <sankurece@gmail.com> : DS1343 Nvram Support
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/spi/spi.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/pm.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/slab.h>
+
+#define DALLAS_MAXIM_DS1343	0
+#define DALLAS_MAXIM_DS1344	1
+
+/* RTC DS1343 Registers */
+#define DS1343_SECONDS_REG	0x00
+#define DS1343_MINUTES_REG	0x01
+#define DS1343_HOURS_REG	0x02
+#define DS1343_DAY_REG		0x03
+#define DS1343_DATE_REG		0x04
+#define DS1343_MONTH_REG	0x05
+#define DS1343_YEAR_REG		0x06
+#define DS1343_ALM0_SEC_REG	0x07
+#define DS1343_ALM0_MIN_REG	0x08
+#define DS1343_ALM0_HOUR_REG	0x09
+#define DS1343_ALM0_DAY_REG	0x0A
+#define DS1343_ALM1_SEC_REG	0x0B
+#define DS1343_ALM1_MIN_REG	0x0C
+#define DS1343_ALM1_HOUR_REG	0x0D
+#define DS1343_ALM1_DAY_REG	0x0E
+#define DS1343_CONTROL_REG	0x0F
+#define DS1343_STATUS_REG	0x10
+#define DS1343_TRICKLE_REG	0x11
+#define DS1343_NVRAM		0x20
+
+#define DS1343_NVRAM_LEN	96
+
+/* DS1343 Control Registers bits */
+#define DS1343_EOSC		0x80
+#define DS1343_DOSF		0x20
+#define DS1343_EGFIL		0x10
+#define DS1343_SQW		0x08
+#define DS1343_INTCN		0x04
+#define DS1343_A1IE		0x02
+#define DS1343_A0IE		0x01
+
+/* DS1343 Status Registers bits */
+#define DS1343_OSF		0x80
+#define DS1343_IRQF1		0x02
+#define DS1343_IRQF0		0x01
+
+/* DS1343 Trickle Charger Registers bits */
+#define DS1343_TRICKLE_MAGIC	0xa0
+#define DS1343_TRICKLE_DS1	0x08
+#define DS1343_TRICKLE_1K	0x01
+#define DS1343_TRICKLE_2K	0x02
+#define DS1343_TRICKLE_4K	0x03
+
+static const struct spi_device_id ds1343_id[] = {
+	{ "ds1343", DALLAS_MAXIM_DS1343 },
+	{ "ds1344", DALLAS_MAXIM_DS1344 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, ds1343_id);
+
+struct ds1343_priv {
+	struct rtc_device *rtc;
+	struct regmap *map;
+	int irq;
+};
+
+static ssize_t ds1343_show_glitchfilter(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct ds1343_priv *priv = dev_get_drvdata(dev->parent);
+	int glitch_filt_status, data;
+	int res;
+
+	res = regmap_read(priv->map, DS1343_CONTROL_REG, &data);
+	if (res)
+		return res;
+
+	glitch_filt_status = !!(data & DS1343_EGFIL);
+
+	if (glitch_filt_status)
+		return sprintf(buf, "enabled\n");
+	else
+		return sprintf(buf, "disabled\n");
+}
+
+static ssize_t ds1343_store_glitchfilter(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t count)
+{
+	struct ds1343_priv *priv = dev_get_drvdata(dev->parent);
+	int data = 0;
+	int res;
+
+	if (strncmp(buf, "enabled", 7) == 0)
+		data = DS1343_EGFIL;
+	else if (strncmp(buf, "disabled", 8))
+		return -EINVAL;
+
+	res = regmap_update_bits(priv->map, DS1343_CONTROL_REG,
+				 DS1343_EGFIL, data);
+	if (res)
+		return res;
+
+	return count;
+}
+
+static DEVICE_ATTR(glitch_filter, S_IRUGO | S_IWUSR, ds1343_show_glitchfilter,
+			ds1343_store_glitchfilter);
+
+static int ds1343_nvram_write(void *priv, unsigned int off, void *val,
+			      size_t bytes)
+{
+	struct ds1343_priv *ds1343 = priv;
+
+	return regmap_bulk_write(ds1343->map, DS1343_NVRAM + off, val, bytes);
+}
+
+static int ds1343_nvram_read(void *priv, unsigned int off, void *val,
+			     size_t bytes)
+{
+	struct ds1343_priv *ds1343 = priv;
+
+	return regmap_bulk_read(ds1343->map, DS1343_NVRAM + off, val, bytes);
+}
+
+static ssize_t ds1343_show_tricklecharger(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct ds1343_priv *priv = dev_get_drvdata(dev->parent);
+	int res, data;
+	char *diodes = "disabled", *resistors = " ";
+
+	res = regmap_read(priv->map, DS1343_TRICKLE_REG, &data);
+	if (res)
+		return res;
+
+	if ((data & 0xf0) == DS1343_TRICKLE_MAGIC) {
+		switch (data & 0x0c) {
+		case DS1343_TRICKLE_DS1:
+			diodes = "one diode,";
+			break;
+
+		default:
+			diodes = "no diode,";
+			break;
+		}
+
+		switch (data & 0x03) {
+		case DS1343_TRICKLE_1K:
+			resistors = "1k Ohm";
+			break;
+
+		case DS1343_TRICKLE_2K:
+			resistors = "2k Ohm";
+			break;
+
+		case DS1343_TRICKLE_4K:
+			resistors = "4k Ohm";
+			break;
+
+		default:
+			diodes = "disabled";
+			break;
+		}
+	}
+
+	return sprintf(buf, "%s %s\n", diodes, resistors);
+}
+
+static DEVICE_ATTR(trickle_charger, S_IRUGO, ds1343_show_tricklecharger, NULL);
+
+static struct attribute *ds1343_attrs[] = {
+	&dev_attr_glitch_filter.attr,
+	&dev_attr_trickle_charger.attr,
+	NULL
+};
+
+static const struct attribute_group ds1343_attr_group = {
+	.attrs  = ds1343_attrs,
+};
+
+static int ds1343_read_time(struct device *dev, struct rtc_time *dt)
+{
+	struct ds1343_priv *priv = dev_get_drvdata(dev);
+	unsigned char buf[7];
+	int res;
+
+	res = regmap_bulk_read(priv->map, DS1343_SECONDS_REG, buf, 7);
+	if (res)
+		return res;
+
+	dt->tm_sec	= bcd2bin(buf[0]);
+	dt->tm_min	= bcd2bin(buf[1]);
+	dt->tm_hour	= bcd2bin(buf[2] & 0x3F);
+	dt->tm_wday	= bcd2bin(buf[3]) - 1;
+	dt->tm_mday	= bcd2bin(buf[4]);
+	dt->tm_mon	= bcd2bin(buf[5] & 0x1F) - 1;
+	dt->tm_year	= bcd2bin(buf[6]) + 100; /* year offset from 1900 */
+
+	return 0;
+}
+
+static int ds1343_set_time(struct device *dev, struct rtc_time *dt)
+{
+	struct ds1343_priv *priv = dev_get_drvdata(dev);
+	u8 buf[7];
+
+	buf[0] = bin2bcd(dt->tm_sec);
+	buf[1] = bin2bcd(dt->tm_min);
+	buf[2] = bin2bcd(dt->tm_hour) & 0x3F;
+	buf[3] = bin2bcd(dt->tm_wday + 1);
+	buf[4] = bin2bcd(dt->tm_mday);
+	buf[5] = bin2bcd(dt->tm_mon + 1);
+	buf[6] = bin2bcd(dt->tm_year - 100);
+
+	return regmap_bulk_write(priv->map, DS1343_SECONDS_REG,
+				 buf, sizeof(buf));
+}
+
+static int ds1343_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct ds1343_priv *priv = dev_get_drvdata(dev);
+	unsigned char buf[4];
+	unsigned int val;
+	int res;
+
+	if (priv->irq <= 0)
+		return -EINVAL;
+
+	res = regmap_read(priv->map, DS1343_STATUS_REG, &val);
+	if (res)
+		return res;
+
+	alarm->pending = !!(val & DS1343_IRQF0);
+
+	res = regmap_read(priv->map, DS1343_CONTROL_REG, &val);
+	if (res)
+		return res;
+	alarm->enabled = !!(val & DS1343_A0IE);
+
+	res = regmap_bulk_read(priv->map, DS1343_ALM0_SEC_REG, buf, 4);
+	if (res)
+		return res;
+
+	alarm->time.tm_sec = bcd2bin(buf[0]) & 0x7f;
+	alarm->time.tm_min = bcd2bin(buf[1]) & 0x7f;
+	alarm->time.tm_hour = bcd2bin(buf[2]) & 0x3f;
+	alarm->time.tm_mday = bcd2bin(buf[3]) & 0x3f;
+
+	return 0;
+}
+
+static int ds1343_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct ds1343_priv *priv = dev_get_drvdata(dev);
+	unsigned char buf[4];
+	int res = 0;
+
+	if (priv->irq <= 0)
+		return -EINVAL;
+
+	res = regmap_update_bits(priv->map, DS1343_CONTROL_REG, DS1343_A0IE, 0);
+	if (res)
+		return res;
+
+	buf[0] = bin2bcd(alarm->time.tm_sec);
+	buf[1] = bin2bcd(alarm->time.tm_min);
+	buf[2] = bin2bcd(alarm->time.tm_hour);
+	buf[3] = bin2bcd(alarm->time.tm_mday);
+
+	res = regmap_bulk_write(priv->map, DS1343_ALM0_SEC_REG, buf, 4);
+	if (res)
+		return res;
+
+	if (alarm->enabled)
+		res = regmap_update_bits(priv->map, DS1343_CONTROL_REG,
+					 DS1343_A0IE, DS1343_A0IE);
+
+	return res;
+}
+
+static int ds1343_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+	struct ds1343_priv *priv = dev_get_drvdata(dev);
+
+	if (priv->irq <= 0)
+		return -EINVAL;
+
+	return regmap_update_bits(priv->map, DS1343_CONTROL_REG,
+				  DS1343_A0IE, enabled ? DS1343_A0IE : 0);
+}
+
+static irqreturn_t ds1343_thread(int irq, void *dev_id)
+{
+	struct ds1343_priv *priv = dev_id;
+	unsigned int stat;
+	int res = 0;
+
+	rtc_lock(priv->rtc);
+
+	res = regmap_read(priv->map, DS1343_STATUS_REG, &stat);
+	if (res)
+		goto out;
+
+	if (stat & DS1343_IRQF0) {
+		stat &= ~DS1343_IRQF0;
+		regmap_write(priv->map, DS1343_STATUS_REG, stat);
+
+		rtc_update_irq(priv->rtc, 1, RTC_AF | RTC_IRQF);
+
+		regmap_update_bits(priv->map, DS1343_CONTROL_REG,
+				   DS1343_A0IE, 0);
+	}
+
+out:
+	rtc_unlock(priv->rtc);
+	return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops ds1343_rtc_ops = {
+	.read_time	= ds1343_read_time,
+	.set_time	= ds1343_set_time,
+	.read_alarm	= ds1343_read_alarm,
+	.set_alarm	= ds1343_set_alarm,
+	.alarm_irq_enable = ds1343_alarm_irq_enable,
+};
+
+static int ds1343_probe(struct spi_device *spi)
+{
+	struct ds1343_priv *priv;
+	struct regmap_config config = { .reg_bits = 8, .val_bits = 8,
+					.write_flag_mask = 0x80, };
+	unsigned int data;
+	int res;
+	struct nvmem_config nvmem_cfg = {
+		.name = "ds1343-",
+		.word_size = 1,
+		.stride = 1,
+		.size = DS1343_NVRAM_LEN,
+		.reg_read = ds1343_nvram_read,
+		.reg_write = ds1343_nvram_write,
+	};
+
+	priv = devm_kzalloc(&spi->dev, sizeof(struct ds1343_priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	/* RTC DS1347 works in spi mode 3 and
+	 * its chip select is active high. Active high should be defined as
+	 * "inverse polarity" as GPIO-based chip selects can be logically
+	 * active high but inverted by the GPIO library.
+	 */
+	spi->mode |= SPI_MODE_3;
+	spi->mode ^= SPI_CS_HIGH;
+	spi->bits_per_word = 8;
+	res = spi_setup(spi);
+	if (res)
+		return res;
+
+	spi_set_drvdata(spi, priv);
+
+	priv->map = devm_regmap_init_spi(spi, &config);
+
+	if (IS_ERR(priv->map)) {
+		dev_err(&spi->dev, "spi regmap init failed for rtc ds1343\n");
+		return PTR_ERR(priv->map);
+	}
+
+	res = regmap_read(priv->map, DS1343_SECONDS_REG, &data);
+	if (res)
+		return res;
+
+	regmap_read(priv->map, DS1343_CONTROL_REG, &data);
+	data |= DS1343_INTCN;
+	data &= ~(DS1343_EOSC | DS1343_A1IE | DS1343_A0IE);
+	regmap_write(priv->map, DS1343_CONTROL_REG, data);
+
+	regmap_read(priv->map, DS1343_STATUS_REG, &data);
+	data &= ~(DS1343_OSF | DS1343_IRQF1 | DS1343_IRQF0);
+	regmap_write(priv->map, DS1343_STATUS_REG, data);
+
+	priv->rtc = devm_rtc_allocate_device(&spi->dev);
+	if (IS_ERR(priv->rtc))
+		return PTR_ERR(priv->rtc);
+
+	priv->rtc->ops = &ds1343_rtc_ops;
+	priv->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	priv->rtc->range_max = RTC_TIMESTAMP_END_2099;
+
+	res = rtc_add_group(priv->rtc, &ds1343_attr_group);
+	if (res)
+		dev_err(&spi->dev,
+			"unable to create sysfs entries for rtc ds1343\n");
+
+	res = devm_rtc_register_device(priv->rtc);
+	if (res)
+		return res;
+
+	nvmem_cfg.priv = priv;
+	devm_rtc_nvmem_register(priv->rtc, &nvmem_cfg);
+
+	priv->irq = spi->irq;
+
+	if (priv->irq >= 0) {
+		res = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
+						ds1343_thread, IRQF_ONESHOT,
+						"ds1343", priv);
+		if (res) {
+			priv->irq = -1;
+			dev_err(&spi->dev,
+				"unable to request irq for rtc ds1343\n");
+		} else {
+			device_init_wakeup(&spi->dev, true);
+			dev_pm_set_wake_irq(&spi->dev, spi->irq);
+		}
+	}
+
+	return 0;
+}
+
+static void ds1343_remove(struct spi_device *spi)
+{
+	dev_pm_clear_wake_irq(&spi->dev);
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int ds1343_suspend(struct device *dev)
+{
+	struct spi_device *spi = to_spi_device(dev);
+
+	if (spi->irq >= 0 && device_may_wakeup(dev))
+		enable_irq_wake(spi->irq);
+
+	return 0;
+}
+
+static int ds1343_resume(struct device *dev)
+{
+	struct spi_device *spi = to_spi_device(dev);
+
+	if (spi->irq >= 0 && device_may_wakeup(dev))
+		disable_irq_wake(spi->irq);
+
+	return 0;
+}
+
+#endif
+
+static SIMPLE_DEV_PM_OPS(ds1343_pm, ds1343_suspend, ds1343_resume);
+
+static struct spi_driver ds1343_driver = {
+	.driver = {
+		.name = "ds1343",
+		.pm = &ds1343_pm,
+	},
+	.probe = ds1343_probe,
+	.remove = ds1343_remove,
+	.id_table = ds1343_id,
+};
+
+module_spi_driver(ds1343_driver);
+
+MODULE_DESCRIPTION("DS1343 RTC SPI Driver");
+MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com>,"
+		"Ankur Srivastava <sankurece@gmail.com>");
+MODULE_LICENSE("GPL v2");