[PATCH v2 00/11] rtc: rx8010: use regmap instead of i2c smbus API

[PATCH v2 00/11] rtc: rx8010: use regmap instead of i2c smbus API

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

I want to use this driver on a platform where the i2c controller doesn't
speak SMBUS. This series converts the driver to i2c regmap which can
figure out the correct protocol to use.

The actual conversion happens in patch 10, the rest are just cleanups and
refactoring.

v1 -> v2:
- s/parentheses/brackets/g
- add a patch switching the driver to using the preferred RTC API
- rework the patch removing magic values
- use range_max and range_min instead of manual range checks
- add a patch adding a helper variable in probe() for client->dev
- add a patch using sizeof(*rx8010) instead of sizeof(struct rx8010_data)

--

Alexandre: I believe that the implementation of devm_rtc_allocate_device()
and rtc_register_device() is wrong as I explained under the previous
version of this series. I'll send an RFC that reworks this part soon.

Bartosz Golaszewski (11):
  rtc: rx8010: remove unnecessary brackets
  rtc: rx8010: consolidate local variables of the same type
  rtc: rx8010: use tabs instead of spaces for code formatting
  rtc: rx8010: rename ret to err in rx8010_set_time()
  rtc: rx8010: don't use magic values for time buffer length
  rtc: rx8010: drop unnecessary initialization
  rtc: rx8010: use a helper variable for client->dev in probe()
  rtc: rx8010: prefer sizeof(*val) over sizeof(struct type_of_val)
  rtc: rx8010: switch to using the preferred RTC API
  rtc: rx8010: convert to using regmap
  rtc: rx8010: use range checking provided by core RTC code

 drivers/rtc/rtc-rx8010.c | 306 +++++++++++++++++----------------------
 1 file changed, 131 insertions(+), 175 deletions(-)

-- 
2.26.1

[PATCH v2 01/11] rtc: rx8010: remove unnecessary brackets

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Remove brackets wherever they guard a single line.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/rtc/rtc-rx8010.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
index fe010151ec8f..2faf5357a3a5 100644
--- a/drivers/rtc/rtc-rx8010.c
+++ b/drivers/rtc/rtc-rx8010.c
@@ -181,9 +181,8 @@ static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
 		return ret;
 
 	flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
-	if (flagreg < 0) {
+	if (flagreg < 0)
 		return flagreg;
-	}
 
 	if (flagreg & RX8010_FLAG_VLF)
 		ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,
@@ -284,17 +283,15 @@ static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 	int err;
 
 	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
-	if (flagreg < 0) {
+	if (flagreg < 0)
 		return flagreg;
-	}
 
 	if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {
 		rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
 		err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
 						rx8010->ctrlreg);
-		if (err < 0) {
+		if (err < 0)
 			return err;
-		}
 	}
 
 	flagreg &= ~RX8010_FLAG_AF;
-- 
2.26.1

[PATCH v2 02/11] rtc: rx8010: consolidate local variables of the same type

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Move local variables of the same type into a single line for better
readability.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/rtc/rtc-rx8010.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
index 2faf5357a3a5..4c790d33f589 100644
--- a/drivers/rtc/rtc-rx8010.c
+++ b/drivers/rtc/rtc-rx8010.c
@@ -109,8 +109,7 @@ static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
 {
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 	u8 date[7];
-	int flagreg;
-	int err;
+	int flagreg, err;
 
 	flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
 	if (flagreg < 0)
@@ -141,8 +140,7 @@ static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
 {
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 	u8 date[7];
-	int ctrl, flagreg;
-	int ret;
+	int ctrl, flagreg, ret;
 
 	if ((dt->tm_year < 100) || (dt->tm_year > 199))
 		return -EINVAL;
@@ -250,8 +248,7 @@ static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 	struct i2c_client *client = rx8010->client;
 	u8 alarmvals[3];
-	int flagreg;
-	int err;
+	int flagreg, err;
 
 	err = i2c_smbus_read_i2c_block_data(client, RX8010_ALMIN, 3, alarmvals);
 	if (err != 3)
@@ -279,8 +276,7 @@ static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 	struct i2c_client *client = to_i2c_client(dev);
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 	u8 alarmvals[3];
-	int extreg, flagreg;
-	int err;
+	int extreg, flagreg, err;
 
 	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
 	if (flagreg < 0)
@@ -346,9 +342,8 @@ static int rx8010_alarm_irq_enable(struct device *dev,
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
-	int flagreg;
+	int flagreg, err;
 	u8 ctrl;
-	int err;
 
 	ctrl = rx8010->ctrlreg;
 
@@ -387,8 +382,7 @@ static int rx8010_alarm_irq_enable(struct device *dev,
 static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 {
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
-	int tmp;
-	int flagreg;
+	int tmp, flagreg;
 
 	switch (cmd) {
 	case RTC_VL_READ:
-- 
2.26.1

[PATCH v2 03/11] rtc: rx8010: use tabs instead of spaces for code formatting

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The define values in this driver are close to their names and they are
separated by spaces. Use tabs instead and align all defines.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/rtc/rtc-rx8010.c | 58 ++++++++++++++++++++--------------------
 1 file changed, 29 insertions(+), 29 deletions(-)

diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
index 4c790d33f589..2038700a3e8e 100644
--- a/drivers/rtc/rtc-rx8010.c
+++ b/drivers/rtc/rtc-rx8010.c
@@ -13,40 +13,40 @@
 #include <linux/module.h>
 #include <linux/rtc.h>
 
-#define RX8010_SEC     0x10
-#define RX8010_MIN     0x11
-#define RX8010_HOUR    0x12
-#define RX8010_WDAY    0x13
-#define RX8010_MDAY    0x14
-#define RX8010_MONTH   0x15
-#define RX8010_YEAR    0x16
-#define RX8010_RESV17  0x17
-#define RX8010_ALMIN   0x18
-#define RX8010_ALHOUR  0x19
-#define RX8010_ALWDAY  0x1A
-#define RX8010_TCOUNT0 0x1B
-#define RX8010_TCOUNT1 0x1C
-#define RX8010_EXT     0x1D
-#define RX8010_FLAG    0x1E
-#define RX8010_CTRL    0x1F
+#define RX8010_SEC		0x10
+#define RX8010_MIN		0x11
+#define RX8010_HOUR		0x12
+#define RX8010_WDAY		0x13
+#define RX8010_MDAY		0x14
+#define RX8010_MONTH		0x15
+#define RX8010_YEAR		0x16
+#define RX8010_RESV17		0x17
+#define RX8010_ALMIN		0x18
+#define RX8010_ALHOUR		0x19
+#define RX8010_ALWDAY		0x1A
+#define RX8010_TCOUNT0		0x1B
+#define RX8010_TCOUNT1		0x1C
+#define RX8010_EXT		0x1D
+#define RX8010_FLAG		0x1E
+#define RX8010_CTRL		0x1F
 /* 0x20 to 0x2F are user registers */
-#define RX8010_RESV30  0x30
-#define RX8010_RESV31  0x31
-#define RX8010_IRQ     0x32
+#define RX8010_RESV30		0x30
+#define RX8010_RESV31		0x31
+#define RX8010_IRQ		0x32
 
-#define RX8010_EXT_WADA  BIT(3)
+#define RX8010_EXT_WADA		BIT(3)
 
-#define RX8010_FLAG_VLF  BIT(1)
-#define RX8010_FLAG_AF   BIT(3)
-#define RX8010_FLAG_TF   BIT(4)
-#define RX8010_FLAG_UF   BIT(5)
+#define RX8010_FLAG_VLF		BIT(1)
+#define RX8010_FLAG_AF		BIT(3)
+#define RX8010_FLAG_TF		BIT(4)
+#define RX8010_FLAG_UF		BIT(5)
 
-#define RX8010_CTRL_AIE  BIT(3)
-#define RX8010_CTRL_UIE  BIT(5)
-#define RX8010_CTRL_STOP BIT(6)
-#define RX8010_CTRL_TEST BIT(7)
+#define RX8010_CTRL_AIE		BIT(3)
+#define RX8010_CTRL_UIE		BIT(5)
+#define RX8010_CTRL_STOP	BIT(6)
+#define RX8010_CTRL_TEST	BIT(7)
 
-#define RX8010_ALARM_AE  BIT(7)
+#define RX8010_ALARM_AE		BIT(7)
 
 static const struct i2c_device_id rx8010_id[] = {
 	{ "rx8010", 0 },
-- 
2.26.1

[PATCH v2 04/11] rtc: rx8010: rename ret to err in rx8010_set_time()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

All other functions in this driver use 'err' for integer return values.
Do the same in rx8010_set_time() for consistency.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/rtc/rtc-rx8010.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
index 2038700a3e8e..67ff06a76629 100644
--- a/drivers/rtc/rtc-rx8010.c
+++ b/drivers/rtc/rtc-rx8010.c
@@ -140,7 +140,7 @@ static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
 {
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 	u8 date[7];
-	int ctrl, flagreg, ret;
+	int ctrl, flagreg, err;
 
 	if ((dt->tm_year < 100) || (dt->tm_year > 199))
 		return -EINVAL;
@@ -150,10 +150,10 @@ static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
 	if (ctrl < 0)
 		return ctrl;
 	rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP;
-	ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
+	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
 					rx8010->ctrlreg);
-	if (ret < 0)
-		return ret;
+	if (err < 0)
+		return err;
 
 	date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec);
 	date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min);
@@ -163,27 +163,27 @@ static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
 	date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100);
 	date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday);
 
-	ret = i2c_smbus_write_i2c_block_data(rx8010->client,
+	err = i2c_smbus_write_i2c_block_data(rx8010->client,
 					     RX8010_SEC, 7, date);
-	if (ret < 0)
-		return ret;
+	if (err < 0)
+		return err;
 
 	/* clear STOP bit after changing clock/calendar */
 	ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);
 	if (ctrl < 0)
 		return ctrl;
 	rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP;
-	ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
+	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
 					rx8010->ctrlreg);
-	if (ret < 0)
-		return ret;
+	if (err < 0)
+		return err;
 
 	flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
 	if (flagreg < 0)
 		return flagreg;
 
 	if (flagreg & RX8010_FLAG_VLF)
-		ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,
+		err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,
 						flagreg & ~RX8010_FLAG_VLF);
 
 	return 0;
-- 
2.26.1

[PATCH v2 05/11] rtc: rx8010: don't use magic values for time buffer length

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The time buffer len is used directly in this driver. For readability
it's better to define it as the difference between the date register
offsets and use sizeof() whenever referencing it.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/rtc/rtc-rx8010.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
index 67ff06a76629..b065973b8a14 100644
--- a/drivers/rtc/rtc-rx8010.c
+++ b/drivers/rtc/rtc-rx8010.c
@@ -108,7 +108,7 @@ static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
 static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
 {
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
-	u8 date[7];
+	u8 date[RX8010_YEAR - RX8010_SEC + 1];
 	int flagreg, err;
 
 	flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
@@ -121,8 +121,8 @@ static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
 	}
 
 	err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_SEC,
-					    7, date);
-	if (err != 7)
+					    sizeof(date), date);
+	if (err != sizeof(date))
 		return err < 0 ? err : -EIO;
 
 	dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);
@@ -139,7 +139,7 @@ static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
 static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
 {
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
-	u8 date[7];
+	u8 date[RX8010_YEAR - RX8010_SEC + 1];
 	int ctrl, flagreg, err;
 
 	if ((dt->tm_year < 100) || (dt->tm_year > 199))
@@ -164,7 +164,8 @@ static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
 	date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday);
 
 	err = i2c_smbus_write_i2c_block_data(rx8010->client,
-					     RX8010_SEC, 7, date);
+					     RX8010_SEC, sizeof(date),
+					     date);
 	if (err < 0)
 		return err;
 
-- 
2.26.1

[PATCH v2 06/11] rtc: rx8010: drop unnecessary initialization

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

The 'err' local variable in rx8010_init_client() doesn't need to be
initialized.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/rtc/rtc-rx8010.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
index b065973b8a14..3b8a95330a0a 100644
--- a/drivers/rtc/rtc-rx8010.c
+++ b/drivers/rtc/rtc-rx8010.c
@@ -194,7 +194,7 @@ static int rx8010_init_client(struct i2c_client *client)
 {
 	struct rx8010_data *rx8010 = i2c_get_clientdata(client);
 	u8 ctrl[2];
-	int need_clear = 0, err = 0;
+	int need_clear = 0, err;
 
 	/* Initialize reserved registers as specified in datasheet */
 	err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8);
-- 
2.26.1

[PATCH v2 07/11] rtc: rx8010: use a helper variable for client->dev in probe()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Simple 'dev' looks better then repeated &client->dev and has the added
benefit of avoiding unnecessary line breaks.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/rtc/rtc-rx8010.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
index 3b8a95330a0a..e401d8ed0e19 100644
--- a/drivers/rtc/rtc-rx8010.c
+++ b/drivers/rtc/rtc-rx8010.c
@@ -409,6 +409,7 @@ static int rx8010_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	struct i2c_adapter *adapter = client->adapter;
+	struct device *dev = &client->dev;
 	struct rx8010_data *rx8010;
 	int err = 0;
 
@@ -418,8 +419,7 @@ static int rx8010_probe(struct i2c_client *client,
 		return -EIO;
 	}
 
-	rx8010 = devm_kzalloc(&client->dev, sizeof(struct rx8010_data),
-			      GFP_KERNEL);
+	rx8010 = devm_kzalloc(dev, sizeof(struct rx8010_data), GFP_KERNEL);
 	if (!rx8010)
 		return -ENOMEM;
 
@@ -431,14 +431,14 @@ static int rx8010_probe(struct i2c_client *client,
 		return err;
 
 	if (client->irq > 0) {
-		dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
-		err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+		dev_info(dev, "IRQ %d supplied\n", client->irq);
+		err = devm_request_threaded_irq(dev, client->irq, NULL,
 						rx8010_irq_1_handler,
 						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 						"rx8010", client);
 
 		if (err) {
-			dev_err(&client->dev, "unable to request IRQ\n");
+			dev_err(dev, "unable to request IRQ\n");
 			client->irq = 0;
 		} else {
 			rx8010_rtc_ops.read_alarm = rx8010_read_alarm;
@@ -447,11 +447,11 @@ static int rx8010_probe(struct i2c_client *client,
 		}
 	}
 
-	rx8010->rtc = devm_rtc_device_register(&client->dev, client->name,
+	rx8010->rtc = devm_rtc_device_register(dev, client->name,
 		&rx8010_rtc_ops, THIS_MODULE);
 
 	if (IS_ERR(rx8010->rtc)) {
-		dev_err(&client->dev, "unable to register the class device\n");
+		dev_err(dev, "unable to register the class device\n");
 		return PTR_ERR(rx8010->rtc);
 	}
 
-- 
2.26.1

[PATCH v2 08/11] rtc: rx8010: prefer sizeof(*val) over sizeof(struct type_of_val)

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Using the size of the variable is preferred over using the size of its
type when allocating memory. Convert the call to devm_kzalloc() in
probe().

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/rtc/rtc-rx8010.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
index e401d8ed0e19..0665878e8843 100644
--- a/drivers/rtc/rtc-rx8010.c
+++ b/drivers/rtc/rtc-rx8010.c
@@ -419,7 +419,7 @@ static int rx8010_probe(struct i2c_client *client,
 		return -EIO;
 	}
 
-	rx8010 = devm_kzalloc(dev, sizeof(struct rx8010_data), GFP_KERNEL);
+	rx8010 = devm_kzalloc(dev, sizeof(*rx8010), GFP_KERNEL);
 	if (!rx8010)
 		return -ENOMEM;
 
-- 
2.26.1

[PATCH v2 09/11] rtc: rx8010: switch to using the preferred RTC API

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Use devm_rtc_allocate_device() + rtc_register_device() instead of the
deprecated devm_rtc_device_register().

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/rtc/rtc-rx8010.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
index 0665878e8843..bb6578aad972 100644
--- a/drivers/rtc/rtc-rx8010.c
+++ b/drivers/rtc/rtc-rx8010.c
@@ -447,16 +447,21 @@ static int rx8010_probe(struct i2c_client *client,
 		}
 	}
 
-	rx8010->rtc = devm_rtc_device_register(dev, client->name,
-		&rx8010_rtc_ops, THIS_MODULE);
-
+	rx8010->rtc = devm_rtc_allocate_device(dev);
 	if (IS_ERR(rx8010->rtc)) {
-		dev_err(dev, "unable to register the class device\n");
+		dev_err(dev, "unable to allocate rtc device\n");
 		return PTR_ERR(rx8010->rtc);
 	}
 
+	rx8010->rtc->ops = &rx8010_rtc_ops;
 	rx8010->rtc->max_user_freq = 1;
 
+	err = rtc_register_device(rx8010->rtc);
+	if (err) {
+		dev_err(dev, "unable to register the class device\n");
+		return err;
+	}
+
 	return 0;
 }
 
-- 
2.26.1

[PATCH v2 10/11] rtc: rx8010: convert to using regmap

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

This driver requires SMBUS to work. We can relax this requirement if we
switch to using i2c regmap and let the regmap sub-system figure out how
to talk to the bus.

This also has the advantage of shrinking the code for register updates.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/rtc/rtc-rx8010.c | 198 ++++++++++++++++-----------------------
 1 file changed, 79 insertions(+), 119 deletions(-)

diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
index bb6578aad972..636e0de02d9b 100644
--- a/drivers/rtc/rtc-rx8010.c
+++ b/drivers/rtc/rtc-rx8010.c
@@ -11,6 +11,7 @@
 #include <linux/i2c.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/regmap.h>
 #include <linux/rtc.h>
 
 #define RX8010_SEC		0x10
@@ -61,7 +62,7 @@ static const struct of_device_id rx8010_of_match[] = {
 MODULE_DEVICE_TABLE(of, rx8010_of_match);
 
 struct rx8010_data {
-	struct i2c_client *client;
+	struct regmap *regs;
 	struct rtc_device *rtc;
 	u8 ctrlreg;
 };
@@ -70,13 +71,12 @@ static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
 {
 	struct i2c_client *client = dev_id;
 	struct rx8010_data *rx8010 = i2c_get_clientdata(client);
-	int flagreg;
+	int flagreg, err;
 
 	mutex_lock(&rx8010->rtc->ops_lock);
 
-	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
-
-	if (flagreg <= 0) {
+	err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
+	if (err) {
 		mutex_unlock(&rx8010->rtc->ops_lock);
 		return IRQ_NONE;
 	}
@@ -99,10 +99,9 @@ static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
 		rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);
 	}
 
-	i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
-
+	err = regmap_write(rx8010->regs, RX8010_FLAG, flagreg);
 	mutex_unlock(&rx8010->rtc->ops_lock);
-	return IRQ_HANDLED;
+	return err ? IRQ_NONE : IRQ_HANDLED;
 }
 
 static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
@@ -111,19 +110,18 @@ static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
 	u8 date[RX8010_YEAR - RX8010_SEC + 1];
 	int flagreg, err;
 
-	flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
-	if (flagreg < 0)
-		return flagreg;
+	err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
+	if (err)
+		return err;
 
 	if (flagreg & RX8010_FLAG_VLF) {
 		dev_warn(dev, "Frequency stop detected\n");
 		return -EINVAL;
 	}
 
-	err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_SEC,
-					    sizeof(date), date);
-	if (err != sizeof(date))
-		return err < 0 ? err : -EIO;
+	err = regmap_bulk_read(rx8010->regs, RX8010_SEC, date, sizeof(date));
+	if (err)
+		return err;
 
 	dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);
 	dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f);
@@ -140,19 +138,14 @@ static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
 {
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 	u8 date[RX8010_YEAR - RX8010_SEC + 1];
-	int ctrl, flagreg, err;
+	int err;
 
 	if ((dt->tm_year < 100) || (dt->tm_year > 199))
 		return -EINVAL;
 
 	/* set STOP bit before changing clock/calendar */
-	ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);
-	if (ctrl < 0)
-		return ctrl;
-	rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP;
-	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
-					rx8010->ctrlreg);
-	if (err < 0)
+	err = regmap_set_bits(rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP);
+	if (err)
 		return err;
 
 	date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec);
@@ -163,66 +156,54 @@ static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
 	date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100);
 	date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday);
 
-	err = i2c_smbus_write_i2c_block_data(rx8010->client,
-					     RX8010_SEC, sizeof(date),
-					     date);
-	if (err < 0)
+	err = regmap_bulk_write(rx8010->regs, RX8010_SEC, date, sizeof(date));
+	if (err)
 		return err;
 
 	/* clear STOP bit after changing clock/calendar */
-	ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);
-	if (ctrl < 0)
-		return ctrl;
-	rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP;
-	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
-					rx8010->ctrlreg);
-	if (err < 0)
+	err = regmap_clear_bits(rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP);
+	if (err)
 		return err;
 
-	flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
-	if (flagreg < 0)
-		return flagreg;
-
-	if (flagreg & RX8010_FLAG_VLF)
-		err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,
-						flagreg & ~RX8010_FLAG_VLF);
+	err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_VLF);
+	if (err)
+		return err;
 
 	return 0;
 }
 
-static int rx8010_init_client(struct i2c_client *client)
+static int rx8010_init_client(struct device *dev)
 {
-	struct rx8010_data *rx8010 = i2c_get_clientdata(client);
+	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 	u8 ctrl[2];
 	int need_clear = 0, err;
 
 	/* Initialize reserved registers as specified in datasheet */
-	err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8);
-	if (err < 0)
+	err = regmap_write(rx8010->regs, RX8010_RESV17, 0xD8);
+	if (err)
 		return err;
 
-	err = i2c_smbus_write_byte_data(client, RX8010_RESV30, 0x00);
-	if (err < 0)
+	err = regmap_write(rx8010->regs, RX8010_RESV30, 0x00);
+	if (err)
 		return err;
 
-	err = i2c_smbus_write_byte_data(client, RX8010_RESV31, 0x08);
-	if (err < 0)
+	err = regmap_write(rx8010->regs, RX8010_RESV31, 0x08);
+	if (err)
 		return err;
 
-	err = i2c_smbus_write_byte_data(client, RX8010_IRQ, 0x00);
-	if (err < 0)
+	err = regmap_write(rx8010->regs, RX8010_IRQ, 0x00);
+	if (err)
 		return err;
 
-	err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_FLAG,
-					    2, ctrl);
-	if (err != 2)
-		return err < 0 ? err : -EIO;
+	err = regmap_bulk_read(rx8010->regs, RX8010_FLAG, ctrl, 2);
+	if (err)
+		return err;
 
 	if (ctrl[0] & RX8010_FLAG_VLF)
-		dev_warn(&client->dev, "Frequency stop was detected\n");
+		dev_warn(dev, "Frequency stop was detected\n");
 
 	if (ctrl[0] & RX8010_FLAG_AF) {
-		dev_warn(&client->dev, "Alarm was detected\n");
+		dev_warn(dev, "Alarm was detected\n");
 		need_clear = 1;
 	}
 
@@ -234,8 +215,8 @@ static int rx8010_init_client(struct i2c_client *client)
 
 	if (need_clear) {
 		ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF);
-		err = i2c_smbus_write_byte_data(client, RX8010_FLAG, ctrl[0]);
-		if (err < 0)
+		err = regmap_write(rx8010->regs, RX8010_FLAG, ctrl[0]);
+		if (err)
 			return err;
 	}
 
@@ -247,17 +228,16 @@ static int rx8010_init_client(struct i2c_client *client)
 static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 {
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
-	struct i2c_client *client = rx8010->client;
 	u8 alarmvals[3];
 	int flagreg, err;
 
-	err = i2c_smbus_read_i2c_block_data(client, RX8010_ALMIN, 3, alarmvals);
-	if (err != 3)
-		return err < 0 ? err : -EIO;
+	err = regmap_bulk_read(rx8010->regs, RX8010_ALMIN, alarmvals, 3);
+	if (err)
+		return err;
 
-	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
-	if (flagreg < 0)
-		return flagreg;
+	err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
+	if (err)
+		return err;
 
 	t->time.tm_sec = 0;
 	t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
@@ -274,52 +254,38 @@ static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 
 static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 {
-	struct i2c_client *client = to_i2c_client(dev);
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
 	u8 alarmvals[3];
-	int extreg, flagreg, err;
-
-	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
-	if (flagreg < 0)
-		return flagreg;
+	int err;
 
 	if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {
 		rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
-		err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
-						rx8010->ctrlreg);
-		if (err < 0)
+		err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
+		if (err)
 			return err;
 	}
 
-	flagreg &= ~RX8010_FLAG_AF;
-	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
-	if (err < 0)
+	err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF);
+	if (err)
 		return err;
 
 	alarmvals[0] = bin2bcd(t->time.tm_min);
 	alarmvals[1] = bin2bcd(t->time.tm_hour);
 	alarmvals[2] = bin2bcd(t->time.tm_mday);
 
-	err = i2c_smbus_write_i2c_block_data(rx8010->client, RX8010_ALMIN,
-					     2, alarmvals);
-	if (err < 0)
+	err = regmap_bulk_write(rx8010->regs, RX8010_ALMIN, alarmvals, 2);
+	if (err)
 		return err;
 
-	extreg = i2c_smbus_read_byte_data(client, RX8010_EXT);
-	if (extreg < 0)
-		return extreg;
-
-	extreg |= RX8010_EXT_WADA;
-	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_EXT, extreg);
-	if (err < 0)
+	err = regmap_clear_bits(rx8010->regs, RX8010_EXT, RX8010_EXT_WADA);
+	if (err)
 		return err;
 
 	if (alarmvals[2] == 0)
 		alarmvals[2] |= RX8010_ALARM_AE;
 
-	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_ALWDAY,
-					alarmvals[2]);
-	if (err < 0)
+	err = regmap_write(rx8010->regs, RX8010_ALWDAY, alarmvals[2]);
+	if (err)
 		return err;
 
 	if (t->enabled) {
@@ -329,9 +295,8 @@ static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 			rx8010->ctrlreg |=
 				(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
 
-		err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
-						rx8010->ctrlreg);
-		if (err < 0)
+		err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
+		if (err)
 			return err;
 	}
 
@@ -341,9 +306,8 @@ static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 static int rx8010_alarm_irq_enable(struct device *dev,
 				   unsigned int enabled)
 {
-	struct i2c_client *client = to_i2c_client(dev);
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
-	int flagreg, err;
+	int err;
 	u8 ctrl;
 
 	ctrl = rx8010->ctrlreg;
@@ -360,20 +324,14 @@ static int rx8010_alarm_irq_enable(struct device *dev,
 			ctrl &= ~RX8010_CTRL_AIE;
 	}
 
-	flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
-	if (flagreg < 0)
-		return flagreg;
-
-	flagreg &= ~RX8010_FLAG_AF;
-	err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
-	if (err < 0)
+	err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF);
+	if (err)
 		return err;
 
 	if (ctrl != rx8010->ctrlreg) {
 		rx8010->ctrlreg = ctrl;
-		err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
-						rx8010->ctrlreg);
-		if (err < 0)
+		err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
+		if (err)
 			return err;
 	}
 
@@ -383,13 +341,13 @@ static int rx8010_alarm_irq_enable(struct device *dev,
 static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 {
 	struct rx8010_data *rx8010 = dev_get_drvdata(dev);
-	int tmp, flagreg;
+	int tmp, flagreg, err;
 
 	switch (cmd) {
 	case RTC_VL_READ:
-		flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
-		if (flagreg < 0)
-			return flagreg;
+		err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
+		if (err)
+			return err;
 
 		tmp = flagreg & RX8010_FLAG_VLF ? RTC_VL_DATA_INVALID : 0;
 		return put_user(tmp, (unsigned int __user *)arg);
@@ -405,28 +363,30 @@ static struct rtc_class_ops rx8010_rtc_ops = {
 	.ioctl = rx8010_ioctl,
 };
 
+static const struct regmap_config rx8010_regmap_config = {
+	.name = "rx8010-rtc",
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
 static int rx8010_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
-	struct i2c_adapter *adapter = client->adapter;
 	struct device *dev = &client->dev;
 	struct rx8010_data *rx8010;
 	int err = 0;
 
-	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
-		| I2C_FUNC_SMBUS_I2C_BLOCK)) {
-		dev_err(&adapter->dev, "doesn't support required functionality\n");
-		return -EIO;
-	}
-
 	rx8010 = devm_kzalloc(dev, sizeof(*rx8010), GFP_KERNEL);
 	if (!rx8010)
 		return -ENOMEM;
 
-	rx8010->client = client;
 	i2c_set_clientdata(client, rx8010);
 
-	err = rx8010_init_client(client);
+	rx8010->regs = devm_regmap_init_i2c(client, &rx8010_regmap_config);
+	if (IS_ERR(rx8010->regs))
+		return PTR_ERR(rx8010->regs);
+
+	err = rx8010_init_client(dev);
 	if (err)
 		return err;
 
-- 
2.26.1

[PATCH v2 11/11] rtc: rx8010: use range checking provided by core RTC code

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

We don't need to check the time range manually in set_time(), we can
use range_min and range_max exposed by struct rtc_device.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/rtc/rtc-rx8010.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
index 636e0de02d9b..e78f0808bdff 100644
--- a/drivers/rtc/rtc-rx8010.c
+++ b/drivers/rtc/rtc-rx8010.c
@@ -140,9 +140,6 @@ static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
 	u8 date[RX8010_YEAR - RX8010_SEC + 1];
 	int err;
 
-	if ((dt->tm_year < 100) || (dt->tm_year > 199))
-		return -EINVAL;
-
 	/* set STOP bit before changing clock/calendar */
 	err = regmap_set_bits(rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP);
 	if (err)
@@ -415,6 +412,8 @@ static int rx8010_probe(struct i2c_client *client,
 
 	rx8010->rtc->ops = &rx8010_rtc_ops;
 	rx8010->rtc->max_user_freq = 1;
+	rx8010->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+	rx8010->rtc->range_max = RTC_TIMESTAMP_END_2099;
 
 	err = rtc_register_device(rx8010->rtc);
 	if (err) {
-- 
2.26.1

Re: [PATCH v2 09/11] rtc: rx8010: switch to using the preferred RTC API

[Alexandre Belloni]

On 10/09/2020 15:04:44+0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> Use devm_rtc_allocate_device() + rtc_register_device() instead of the
> deprecated devm_rtc_device_register().
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>  drivers/rtc/rtc-rx8010.c | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
> index 0665878e8843..bb6578aad972 100644
> --- a/drivers/rtc/rtc-rx8010.c
> +++ b/drivers/rtc/rtc-rx8010.c
> @@ -447,16 +447,21 @@ static int rx8010_probe(struct i2c_client *client,
>  		}
>  	}
>  
> -	rx8010->rtc = devm_rtc_device_register(dev, client->name,
> -		&rx8010_rtc_ops, THIS_MODULE);
> -
> +	rx8010->rtc = devm_rtc_allocate_device(dev);
>  	if (IS_ERR(rx8010->rtc)) {
> -		dev_err(dev, "unable to register the class device\n");
> +		dev_err(dev, "unable to allocate rtc device\n");
>  		return PTR_ERR(rx8010->rtc);
>  	}
>  
> +	rx8010->rtc->ops = &rx8010_rtc_ops;
>  	rx8010->rtc->max_user_freq = 1;
>  
> +	err = rtc_register_device(rx8010->rtc);
> +	if (err) {
> +		dev_err(dev, "unable to register the class device\n");

There is no path were this would fail silently so I prefer cutting down
on the number of strings in the drivers. So you can just:

	return rtc_register_device(rx8010->rtc);

> +		return err;
> +	}
> +
>  	return 0;
>  }
>  
> -- 
> 2.26.1
> 

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com