1 files changed, 213 insertions, 80 deletions

diff --git a/drivers/rtc/rtc-rv8803.c b/drivers/rtc/rtc-rv8803.c
index aae2576741a6..1327251e527c 100644
--- a/drivers/rtc/rtc-rv8803.c
+++ b/drivers/rtc/rtc-rv8803.c
@@ -1,25 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * RTC driver for the Micro Crystal RV8803
  *
  * Copyright (C) 2015 Micro Crystal SA
- *
- * Alexandre Belloni <alexandre.belloni@free-electrons.com>
- *
- * 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.
+ * Alexandre Belloni <alexandre.belloni@bootlin.com>
  *
  */
 
 #include <linux/bcd.h>
 #include <linux/bitops.h>
+#include <linux/bitfield.h>
 #include <linux/log2.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/of_device.h>
+#include <linux/of.h>
 #include <linux/rtc.h>
+#include <linux/pm_wakeirq.h>
 
 #define RV8803_I2C_TRY_COUNT		4
 
@@ -37,6 +35,7 @@
 #define RV8803_EXT			0x0D
 #define RV8803_FLAG			0x0E
 #define RV8803_CTRL			0x0F
+#define RV8803_OSC_OFFSET		0x2C
 
 #define RV8803_EXT_WADA			BIT(6)
 
@@ -53,12 +52,16 @@
 #define RV8803_CTRL_TIE			BIT(4)
 #define RV8803_CTRL_UIE			BIT(5)
 
+#define RX8803_CTRL_CSEL		GENMASK(7, 6)
+
 #define RX8900_BACKUP_CTRL		0x18
 #define RX8900_FLAG_SWOFF		BIT(2)
 #define RX8900_FLAG_VDETOFF		BIT(3)
 
 enum rv8803_type {
 	rv_8803,
+	rx_8803,
+	rx_8804,
 	rx_8900
 };
 
@@ -67,8 +70,9 @@ struct rv8803_data {
 	struct rtc_device *rtc;
 	struct mutex flags_lock;
 	u8 ctrl;
+	u8 backup;
+	u8 alarm_invalid:1;
 	enum rv8803_type type;
-	struct nvmem_config nvmem_cfg;
 };
 
 static int rv8803_read_reg(const struct i2c_client *client, u8 reg)
@@ -140,6 +144,44 @@ static int rv8803_write_regs(const struct i2c_client *client,
 	return ret;
 }
 
+static int rv8803_regs_init(struct rv8803_data *rv8803)
+{
+	int ret;
+
+	ret = rv8803_write_reg(rv8803->client, RV8803_OSC_OFFSET, 0x00);
+	if (ret)
+		return ret;
+
+	ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
+			       FIELD_PREP(RX8803_CTRL_CSEL, 1)); /* 2s */
+	if (ret)
+		return ret;
+
+	ret = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3,
+				(u8[]){ 0, 0, 0 });
+	if (ret)
+		return ret;
+
+	return rv8803_write_reg(rv8803->client, RV8803_RAM, 0x00);
+}
+
+static int rv8803_regs_configure(struct rv8803_data *rv8803);
+
+static int rv8803_regs_reset(struct rv8803_data *rv8803, bool full)
+{
+	/*
+	 * The RV-8803 resets all registers to POR defaults after voltage-loss,
+	 * the Epson RTCs don't, so we manually reset the remainder here.
+	 */
+	if (full || rv8803->type == rx_8803 || rv8803->type == rx_8900) {
+		int ret = rv8803_regs_init(rv8803);
+		if (ret)
+			return ret;
+	}
+
+	return rv8803_regs_configure(rv8803);
+}
+
 static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
 {
 	struct i2c_client *client = dev_id;
@@ -198,6 +240,11 @@ static int rv8803_get_time(struct device *dev, struct rtc_time *tm)
 	u8 *date = date1;
 	int ret, flags;
 
+	if (rv8803->alarm_invalid) {
+		dev_warn(dev, "Corruption detected, data may be invalid.\n");
+		return -EINVAL;
+	}
+
 	flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
 	if (flags < 0)
 		return flags;
@@ -237,9 +284,6 @@ static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
 	u8 date[7];
 	int ctrl, flags, ret;
 
-	if ((tm->tm_year < 100) || (tm->tm_year > 199))
-		return -EINVAL;
-
 	ctrl = rv8803_read_reg(rv8803->client, RV8803_CTRL);
 	if (ctrl < 0)
 		return ctrl;
@@ -276,6 +320,21 @@ static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
 		return flags;
 	}
 
+	if ((flags & RV8803_FLAG_V2F) || rv8803->alarm_invalid) {
+		/*
+		 * If we sense corruption in the alarm registers, but see no
+		 * voltage loss flag, we can't rely on other registers having
+		 * sensible values. Reset them fully.
+		 */
+		ret = rv8803_regs_reset(rv8803, rv8803->alarm_invalid);
+		if (ret) {
+			mutex_unlock(&rv8803->flags_lock);
+			return ret;
+		}
+
+		rv8803->alarm_invalid = false;
+	}
+
 	ret = rv8803_write_reg(rv8803->client, RV8803_FLAG,
 			       flags & ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F));
 
@@ -299,15 +358,33 @@ static int rv8803_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	if (flags < 0)
 		return flags;
 
+	alarmvals[0] &= 0x7f;
+	alarmvals[1] &= 0x3f;
+	alarmvals[2] &= 0x3f;
+
+	if (!bcd_is_valid(alarmvals[0]) ||
+	    !bcd_is_valid(alarmvals[1]) ||
+	    !bcd_is_valid(alarmvals[2]))
+		goto err_invalid;
+
 	alrm->time.tm_sec  = 0;
-	alrm->time.tm_min  = bcd2bin(alarmvals[0] & 0x7f);
-	alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
-	alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
+	alrm->time.tm_min  = bcd2bin(alarmvals[0]);
+	alrm->time.tm_hour = bcd2bin(alarmvals[1]);
+	alrm->time.tm_mday = bcd2bin(alarmvals[2]);
 
 	alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE);
 	alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled;
 
+	if ((unsigned int)alrm->time.tm_mday > 31 ||
+	    (unsigned int)alrm->time.tm_hour >= 24 ||
+	    (unsigned int)alrm->time.tm_min >= 60)
+		goto err_invalid;
+
 	return 0;
+
+err_invalid:
+	rv8803->alarm_invalid = true;
+	return -EINVAL;
 }
 
 static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
@@ -348,8 +425,8 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 		}
 	}
 
-	ctrl[1] &= ~RV8803_FLAG_AF;
-	err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[1]);
+	ctrl[0] &= ~RV8803_FLAG_AF;
+	err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[0]);
 	mutex_unlock(&rv8803->flags_lock);
 	if (err)
 		return err;
@@ -419,6 +496,7 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
+	unsigned int vl = 0;
 	int flags, ret = 0;
 
 	switch (cmd) {
@@ -427,18 +505,15 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 		if (flags < 0)
 			return flags;
 
-		if (flags & RV8803_FLAG_V1F)
+		if (flags & RV8803_FLAG_V1F) {
 			dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
+			vl = RTC_VL_ACCURACY_LOW;
+		}
 
 		if (flags & RV8803_FLAG_V2F)
-			dev_warn(&client->dev, "Voltage low, data loss detected.\n");
-
-		flags &= RV8803_FLAG_V1F | RV8803_FLAG_V2F;
+			vl |= RTC_VL_DATA_INVALID;
 
-		if (copy_to_user((void __user *)arg, &flags, sizeof(int)))
-			return -EFAULT;
-
-		return 0;
+		return put_user(vl, (unsigned int __user *)arg);
 
 	case RTC_VL_CLR:
 		mutex_lock(&rv8803->flags_lock);
@@ -448,7 +523,7 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 			return flags;
 		}
 
-		flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F);
+		flags &= ~RV8803_FLAG_V1F;
 		ret = rv8803_write_reg(client, RV8803_FLAG, flags);
 		mutex_unlock(&rv8803->flags_lock);
 		if (ret)
@@ -464,13 +539,7 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 static int rv8803_nvram_write(void *priv, unsigned int offset, void *val,
 			      size_t bytes)
 {
-	int ret;
-
-	ret = rv8803_write_reg(priv, RV8803_RAM, *(u8 *)val);
-	if (ret)
-		return ret;
-
-	return 0;
+	return rv8803_write_reg(priv, RV8803_RAM, *(u8 *)val);
 }
 
 static int rv8803_nvram_read(void *priv, unsigned int offset,
@@ -487,10 +556,13 @@ static int rv8803_nvram_read(void *priv, unsigned int offset,
 	return 0;
 }
 
-static struct rtc_class_ops rv8803_rtc_ops = {
+static const struct rtc_class_ops rv8803_rtc_ops = {
 	.read_time = rv8803_get_time,
 	.set_time = rv8803_set_time,
 	.ioctl = rv8803_ioctl,
+	.read_alarm = rv8803_get_alarm,
+	.set_alarm = rv8803_set_alarm,
+	.alarm_irq_enable = rv8803_alarm_irq_enable,
 };
 
 static int rx8900_trickle_charger_init(struct rv8803_data *rv8803)
@@ -510,24 +582,77 @@ static int rx8900_trickle_charger_init(struct rv8803_data *rv8803)
 	if (err < 0)
 		return err;
 
-	flags = ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF) & (u8)err;
-
-	if (of_property_read_bool(node, "epson,vdet-disable"))
-		flags |= RX8900_FLAG_VDETOFF;
-
-	if (of_property_read_bool(node, "trickle-diode-disable"))
-		flags |= RX8900_FLAG_SWOFF;
+	flags = (u8)err;
+	flags &= ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF);
+	flags |= rv8803->backup;
 
 	return i2c_smbus_write_byte_data(rv8803->client, RX8900_BACKUP_CTRL,
 					 flags);
 }
 
-static int rv8803_probe(struct i2c_client *client,
-			const struct i2c_device_id *id)
+/* configure registers with values different than the Power-On reset defaults */
+static int rv8803_regs_configure(struct rv8803_data *rv8803)
 {
-	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+	int err;
+
+	err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
+	if (err)
+		return err;
+
+	err = rx8900_trickle_charger_init(rv8803);
+	if (err) {
+		dev_err(&rv8803->client->dev, "failed to init charger\n");
+		return err;
+	}
+
+	return 0;
+}
+
+static int rv8803_resume(struct device *dev)
+{
+	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
+
+	if (rv8803->client->irq > 0 && device_may_wakeup(dev))
+		disable_irq_wake(rv8803->client->irq);
+
+	return 0;
+}
+
+static int rv8803_suspend(struct device *dev)
+{
+	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
+
+	if (rv8803->client->irq > 0 && device_may_wakeup(dev))
+		enable_irq_wake(rv8803->client->irq);
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(rv8803_pm_ops, rv8803_suspend, rv8803_resume);
+
+static const struct i2c_device_id rv8803_id[] = {
+	{ "rv8803", rv_8803 },
+	{ "rv8804", rx_8804 },
+	{ "rx8803", rx_8803 },
+	{ "rx8900", rx_8900 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, rv8803_id);
+
+static int rv8803_probe(struct i2c_client *client)
+{
+	struct i2c_adapter *adapter = client->adapter;
 	struct rv8803_data *rv8803;
 	int err, flags;
+	struct nvmem_config nvmem_cfg = {
+		.name = "rv8803_nvram",
+		.word_size = 1,
+		.stride = 1,
+		.size = 1,
+		.reg_read = rv8803_nvram_read,
+		.reg_write = rv8803_nvram_write,
+		.priv = client,
+	};
 
 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 				     I2C_FUNC_SMBUS_I2C_BLOCK)) {
@@ -542,11 +667,13 @@ static int rv8803_probe(struct i2c_client *client,
 
 	mutex_init(&rv8803->flags_lock);
 	rv8803->client = client;
-	if (client->dev.of_node)
-		rv8803->type = (enum rv8803_type)
-			of_device_get_match_data(&client->dev);
-	else
+	if (client->dev.of_node) {
+		rv8803->type = (uintptr_t)of_device_get_match_data(&client->dev);
+	} else {
+		const struct i2c_device_id *id = i2c_match_id(rv8803_id, client);
+
 		rv8803->type = id->driver_data;
+	}
 	i2c_set_clientdata(client, rv8803);
 
 	flags = rv8803_read_reg(client, RV8803_FLAG);
@@ -563,66 +690,71 @@ static int rv8803_probe(struct i2c_client *client,
 		dev_warn(&client->dev, "An alarm maybe have been missed.\n");
 
 	rv8803->rtc = devm_rtc_allocate_device(&client->dev);
-	if (IS_ERR(rv8803->rtc)) {
+	if (IS_ERR(rv8803->rtc))
 		return PTR_ERR(rv8803->rtc);
-	}
 
 	if (client->irq > 0) {
+		unsigned long irqflags = IRQF_TRIGGER_LOW;
+
+		if (dev_fwnode(&client->dev))
+			irqflags = 0;
+
 		err = devm_request_threaded_irq(&client->dev, client->irq,
 						NULL, rv8803_handle_irq,
-						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+						irqflags | IRQF_ONESHOT,
 						"rv8803", client);
 		if (err) {
 			dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
 			client->irq = 0;
 		} else {
-			rv8803_rtc_ops.read_alarm = rv8803_get_alarm;
-			rv8803_rtc_ops.set_alarm = rv8803_set_alarm;
-			rv8803_rtc_ops.alarm_irq_enable = rv8803_alarm_irq_enable;
+			device_init_wakeup(&client->dev, true);
+			err = dev_pm_set_wake_irq(&client->dev, client->irq);
+			if (err)
+				dev_err(&client->dev, "failed to set wake IRQ\n");
 		}
+	} else {
+		if (device_property_read_bool(&client->dev, "wakeup-source"))
+			device_init_wakeup(&client->dev, true);
+		else
+			clear_bit(RTC_FEATURE_ALARM, rv8803->rtc->features);
 	}
 
-	rv8803->nvmem_cfg.name = "rv8803_nvram",
-	rv8803->nvmem_cfg.word_size = 1,
-	rv8803->nvmem_cfg.stride = 1,
-	rv8803->nvmem_cfg.size = 1,
-	rv8803->nvmem_cfg.reg_read = rv8803_nvram_read,
-	rv8803->nvmem_cfg.reg_write = rv8803_nvram_write,
-	rv8803->nvmem_cfg.priv = client;
+	if (of_property_read_bool(client->dev.of_node, "epson,vdet-disable"))
+		rv8803->backup |= RX8900_FLAG_VDETOFF;
 
-	rv8803->rtc->ops = &rv8803_rtc_ops;
-	rv8803->rtc->nvmem_config = &rv8803->nvmem_cfg;
-	rv8803->rtc->nvram_old_abi = true;
-	err = rtc_register_device(rv8803->rtc);
+	if (of_property_read_bool(client->dev.of_node, "trickle-diode-disable"))
+		rv8803->backup |= RX8900_FLAG_SWOFF;
+
+	err = rv8803_regs_configure(rv8803);
 	if (err)
 		return err;
 
-	err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
+	rv8803->rtc->ops = &rv8803_rtc_ops;
+	rv8803->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rv8803->rtc->range_max = RTC_TIMESTAMP_END_2099;
+	err = devm_rtc_register_device(rv8803->rtc);
 	if (err)
 		return err;
 
-	err = rx8900_trickle_charger_init(rv8803);
-	if (err) {
-		dev_err(&client->dev, "failed to init charger\n");
-		return err;
-	}
+	devm_rtc_nvmem_register(rv8803->rtc, &nvmem_cfg);
 
 	rv8803->rtc->max_user_freq = 1;
 
 	return 0;
 }
 
-static const struct i2c_device_id rv8803_id[] = {
-	{ "rv8803", rv_8803 },
-	{ "rx8900", rx_8900 },
-	{ }
-};
-MODULE_DEVICE_TABLE(i2c, rv8803_id);
-
-static const struct of_device_id rv8803_of_match[] = {
+static const __maybe_unused struct of_device_id rv8803_of_match[] = {
 	{
 		.compatible = "microcrystal,rv8803",
-		.data = (void *)rx_8900
+		.data = (void *)rv_8803
+	},
+	{
+		.compatible = "epson,rx8803",
+		.data = (void *)rx_8803
+	},
+	{
+		.compatible = "epson,rx8804",
+		.data = (void *)rx_8804
 	},
 	{
 		.compatible = "epson,rx8900",
@@ -636,12 +768,13 @@ static struct i2c_driver rv8803_driver = {
 	.driver = {
 		.name = "rtc-rv8803",
 		.of_match_table = of_match_ptr(rv8803_of_match),
+		.pm = &rv8803_pm_ops,
 	},
 	.probe		= rv8803_probe,
 	.id_table	= rv8803_id,
 };
 module_i2c_driver(rv8803_driver);
 
-MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
+MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
 MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
 MODULE_LICENSE("GPL v2");