* [PATCH v7 1/9] dt-bindings: rtc: abx80x: document ABX81X RTCs
2026-09-16 20:51 [PATCH v7 0/9] rtc: abx80x: add support for abx81x Antoni Pokusinski
@ 2026-09-16 20:51 ` Antoni Pokusinski
2026-09-16 20:59 ` sashiko-bot
2026-09-16 20:51 ` [PATCH v7 2/9] rtc: abx80x: fix error check after i2c_smbus_read in read_alarm() Antoni Pokusinski
` (8 subsequent siblings)
9 siblings, 1 reply; 22+ messages in thread
From: Antoni Pokusinski @ 2026-09-16 20:51 UTC (permalink / raw)
To: alexandre.belloni, robh, krzk+dt, conor+dt
Cc: linux-rtc, devicetree, linux-kernel, Antoni Pokusinski,
Krzysztof Kozlowski
Abracon AB0815 and AB1815 are RTC modules with SPI interface.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Antoni Pokusinski <apokusinski01@gmail.com>
---
.../bindings/rtc/abracon,abx80x.yaml | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/rtc/abracon,abx80x.yaml b/Documentation/devicetree/bindings/rtc/abracon,abx80x.yaml
index 355b0598411a..d105570bcd5a 100644
--- a/Documentation/devicetree/bindings/rtc/abracon,abx80x.yaml
+++ b/Documentation/devicetree/bindings/rtc/abracon,abx80x.yaml
@@ -4,7 +4,7 @@
$id: http://devicetree.org/schemas/rtc/abracon,abx80x.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
-title: Abracon ABX80X I2C ultra low power RTC/Alarm chip
+title: Abracon ABX80X (I2C) and ABX81X (SPI) ultra low power RTC/Alarm chips
maintainers:
- linux-rtc@vger.kernel.org
@@ -21,10 +21,12 @@ properties:
- abracon,ab0803
- abracon,ab0804
- abracon,ab0805
+ - abracon,ab0815
- abracon,ab1801
- abracon,ab1803
- abracon,ab1804
- abracon,ab1805
+ - abracon,ab1815
- microcrystal,rv1805
reg:
@@ -61,6 +63,7 @@ required:
- reg
allOf:
+ - $ref: /schemas/spi/spi-peripheral-props.yaml#
- $ref: rtc.yaml#
- if:
properties:
@@ -73,6 +76,8 @@ allOf:
- abracon,ab1804
- abracon,ab0805
- abracon,ab1805
+ - abracon,ab0815
+ - abracon,ab1815
then:
properties:
abracon,tc-diode: false
@@ -96,3 +101,14 @@ examples:
interrupts = <44 IRQ_TYPE_EDGE_FALLING>;
};
};
+
+ - |
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ rtc@0 {
+ compatible = "abracon,ab1815";
+ reg = <0>;
+ };
+ };
--
2.55.0
^ permalink raw reply related [flat|nested] 22+ messages in thread* [PATCH v7 2/9] rtc: abx80x: fix error check after i2c_smbus_read in read_alarm()
2026-09-16 20:51 [PATCH v7 0/9] rtc: abx80x: add support for abx81x Antoni Pokusinski
2026-09-16 20:51 ` [PATCH v7 1/9] dt-bindings: rtc: abx80x: document ABX81X RTCs Antoni Pokusinski
@ 2026-09-16 20:51 ` Antoni Pokusinski
2026-09-16 21:01 ` sashiko-bot
2026-09-16 20:51 ` [PATCH v7 3/9] rtc: abx80x: add mutex protection for register writes Antoni Pokusinski
` (7 subsequent siblings)
9 siblings, 1 reply; 22+ messages in thread
From: Antoni Pokusinski @ 2026-09-16 20:51 UTC (permalink / raw)
To: alexandre.belloni, robh, krzk+dt, conor+dt
Cc: linux-rtc, devicetree, linux-kernel, Antoni Pokusinski
i2c_smbus_read_i2c_block_data() returns the number of bytes read on
success and a negative error code on failure. The existing code treated
any non-zero return value as an error.
Fix the error handling by checking only for negative return values.
Fixes: 718a820a303c ("rtc: abx80x: add alarm support")
Signed-off-by: Antoni Pokusinski <apokusinski01@gmail.com>
---
drivers/rtc/rtc-abx80x.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index 5486d9d0b1e5..e4fd7b5d4b11 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -294,8 +294,10 @@ static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
sizeof(buf), buf);
- if (err)
+ if (err < 0)
return err;
+ if (err < ARRAY_SIZE(buf))
+ return -EIO;
irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
if (irq_mask < 0)
@@ -311,7 +313,7 @@ static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE);
t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled;
- return err;
+ return 0;
}
static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
--
2.55.0
^ permalink raw reply related [flat|nested] 22+ messages in thread* [PATCH v7 3/9] rtc: abx80x: add mutex protection for register writes
2026-09-16 20:51 [PATCH v7 0/9] rtc: abx80x: add support for abx81x Antoni Pokusinski
2026-09-16 20:51 ` [PATCH v7 1/9] dt-bindings: rtc: abx80x: document ABX81X RTCs Antoni Pokusinski
2026-09-16 20:51 ` [PATCH v7 2/9] rtc: abx80x: fix error check after i2c_smbus_read in read_alarm() Antoni Pokusinski
@ 2026-09-16 20:51 ` Antoni Pokusinski
2026-09-16 21:02 ` sashiko-bot
2026-09-16 20:51 ` [PATCH v7 4/9] rtc: abx80x: properly handle shared IRQs Antoni Pokusinski
` (6 subsequent siblings)
9 siblings, 1 reply; 22+ messages in thread
From: Antoni Pokusinski @ 2026-09-16 20:51 UTC (permalink / raw)
To: alexandre.belloni, robh, krzk+dt, conor+dt
Cc: linux-rtc, devicetree, linux-kernel, Antoni Pokusinski
The ABX80X RTC driver performs multi-step register operations such as
NVMEM transfers or register writes preceded by a configuration key
write. Add a mutex to serialize all the register writes to protect
these sequences against race conditions.
Signed-off-by: Antoni Pokusinski <apokusinski01@gmail.com>
---
drivers/rtc/rtc-abx80x.c | 45 +++++++++++++++++++++++++++++++++-------
1 file changed, 37 insertions(+), 8 deletions(-)
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index e4fd7b5d4b11..44de234efecf 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -15,6 +15,7 @@
#include <linux/i2c.h>
#include <linux/kstrtox.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/rtc.h>
#include <linux/watchdog.h>
@@ -127,6 +128,7 @@ struct abx80x_priv {
struct rtc_device *rtc;
struct i2c_client *client;
struct watchdog_device wdog;
+ struct mutex lock;
};
static int abx80x_write_config_key(struct i2c_client *client, u8 key)
@@ -219,6 +221,7 @@ static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
+ struct abx80x_priv *priv = i2c_get_clientdata(client);
unsigned char buf[8];
int err, flags;
@@ -234,6 +237,8 @@ static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
buf[ABX8XX_REG_WD] = tm->tm_wday;
+ guard(mutex)(&priv->lock);
+
err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
sizeof(buf), buf);
if (err < 0) {
@@ -263,6 +268,8 @@ static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
struct rtc_device *rtc = priv->rtc;
int status;
+ guard(mutex)(&priv->lock);
+
status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
if (status < 0)
return IRQ_NONE;
@@ -319,6 +326,7 @@ static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct i2c_client *client = to_i2c_client(dev);
+ struct abx80x_priv *priv = i2c_get_clientdata(client);
u8 alarm[6];
int err;
@@ -332,6 +340,8 @@ static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
alarm[4] = bin2bcd(t->time.tm_mday);
alarm[5] = bin2bcd(t->time.tm_mon + 1);
+ guard(mutex)(&priv->lock);
+
err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
sizeof(alarm), alarm);
if (err < 0) {
@@ -354,6 +364,7 @@ static int abx80x_rtc_set_autocalibration(struct device *dev,
int autocalibration)
{
struct i2c_client *client = to_i2c_client(dev);
+ struct abx80x_priv *priv = i2c_get_clientdata(client);
int retval, flags = 0;
if ((autocalibration != 0) && (autocalibration != 1024) &&
@@ -362,6 +373,8 @@ static int abx80x_rtc_set_autocalibration(struct device *dev,
return -EINVAL;
}
+ guard(mutex)(&priv->lock);
+
flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
if (flags < 0)
return flags;
@@ -445,6 +458,7 @@ static ssize_t oscillator_store(struct device *dev,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev->parent);
+ struct abx80x_priv *priv = i2c_get_clientdata(client);
int retval, flags, rc_mode = 0;
if (strncmp(buf, "rc", 2) == 0) {
@@ -456,6 +470,8 @@ static ssize_t oscillator_store(struct device *dev,
return -EINVAL;
}
+ guard(mutex)(&priv->lock);
+
flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
if (flags < 0)
return flags;
@@ -513,8 +529,11 @@ static const struct attribute_group rtc_calib_attr_group = {
static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct i2c_client *client = to_i2c_client(dev);
+ struct abx80x_priv *priv = i2c_get_clientdata(client);
int err;
+ guard(mutex)(&priv->lock);
+
if (enabled)
err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
(ABX8XX_IRQ_IM_1_4 |
@@ -528,6 +547,7 @@ static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
struct i2c_client *client = to_i2c_client(dev);
+ struct abx80x_priv *priv = i2c_get_clientdata(client);
int status, tmp;
switch (cmd) {
@@ -541,16 +561,18 @@ static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
return put_user(tmp, (unsigned int __user *)arg);
case RTC_VL_CLR:
- status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
- if (status < 0)
- return status;
+ scoped_guard(mutex, &priv->lock) {
+ status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
+ if (status < 0)
+ return status;
- status &= ~ABX8XX_STATUS_BLF;
+ status &= ~ABX8XX_STATUS_BLF;
- tmp = i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS,
- status);
- if (tmp < 0)
- return tmp;
+ tmp = i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS,
+ status);
+ if (tmp < 0)
+ return tmp;
+ }
return 0;
@@ -619,6 +641,8 @@ static int __abx80x_wdog_set_timeout(struct watchdog_device *wdog,
struct abx80x_priv *priv = watchdog_get_drvdata(wdog);
u8 val = ABX8XX_WDT_WDS | timeout_bits(timeout);
+ guard(mutex)(&priv->lock);
+
/*
* Writing any timeout to the WDT register resets the watchdog timer.
* Writing 0 disables it.
@@ -703,6 +727,8 @@ static int abx80x_nvmem_xfer(struct abx80x_priv *priv, unsigned int offset,
len = min(lower + bytes, (size_t)ABX8XX_SRAM_WIN_SIZE) - lower;
len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
+ guard(mutex)(&priv->lock);
+
ret = i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_EXTRAM,
extram);
if (ret)
@@ -910,6 +936,9 @@ static int abx80x_probe(struct i2c_client *client)
priv->rtc->ops = &abx80x_rtc_ops;
priv->client = client;
+ err = devm_mutex_init(&client->dev, &priv->lock);
+ if (err)
+ return err;
i2c_set_clientdata(client, priv);
--
2.55.0
^ permalink raw reply related [flat|nested] 22+ messages in thread* [PATCH v7 4/9] rtc: abx80x: properly handle shared IRQs
2026-09-16 20:51 [PATCH v7 0/9] rtc: abx80x: add support for abx81x Antoni Pokusinski
` (2 preceding siblings ...)
2026-09-16 20:51 ` [PATCH v7 3/9] rtc: abx80x: add mutex protection for register writes Antoni Pokusinski
@ 2026-09-16 20:51 ` Antoni Pokusinski
2026-09-16 21:05 ` sashiko-bot
2026-09-16 20:51 ` [PATCH v7 5/9] rtc: abx80x: add irq to struct abx80x_priv Antoni Pokusinski
` (5 subsequent siblings)
9 siblings, 1 reply; 22+ messages in thread
From: Antoni Pokusinski @ 2026-09-16 20:51 UTC (permalink / raw)
To: alexandre.belloni, robh, krzk+dt, conor+dt
Cc: linux-rtc, devicetree, linux-kernel, Antoni Pokusinski
The abx80x RTC driver registers its interrupt handler with IRQF_SHARED,
but the handler always returned IRQ_HANDLED and cleared the status
register even when no interrupt source from the RTC was active.
This could cause the driver to claim interrupts belonging to other
devices sharing the same IRQ line and could also clear unrelated status
bits in the RTC status register.
Only handle the interrupt when the alarm or watchdog flags are set, and
clear only those interrupt status bits that were handled. Return
IRQ_NONE when the interrupt was not generated by the RTC.
Fixes: 718a820a303c ("rtc: abx80x: add alarm support")
Signed-off-by: Antoni Pokusinski <apokusinski01@gmail.com>
---
drivers/rtc/rtc-abx80x.c | 52 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 50 insertions(+), 2 deletions(-)
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index 44de234efecf..2fd0079b7c51 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -51,12 +51,18 @@
#define ABX8XX_CTRL2_RSVD BIT(5)
#define ABX8XX_REG_IRQ 0x12
+#define ABX8XX_IRQ_EX1E BIT(0)
+#define ABX8XX_IRQ_EX2E BIT(1)
#define ABX8XX_IRQ_AIE BIT(2)
+#define ABX8XX_IRQ_TIE BIT(3)
+#define ABX8XX_IRQ_BLIE BIT(4)
#define ABX8XX_IRQ_IM_1_4 (0x3 << 5)
#define ABX8XX_REG_CD_TIMER_CTL 0x18
#define ABX8XX_REG_OSC 0x1c
+#define ABX8XX_OSC_ACIE BIT(0)
+#define ABX8XX_OSC_OFIE BIT(1)
#define ABX8XX_OSC_FOS BIT(3)
#define ABX8XX_OSC_BOS BIT(4)
#define ABX8XX_OSC_ACAL_512 BIT(5)
@@ -266,6 +272,7 @@ static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
struct i2c_client *client = dev_id;
struct abx80x_priv *priv = i2c_get_clientdata(client);
struct rtc_device *rtc = priv->rtc;
+ unsigned int status_flags_clear;
int status;
guard(mutex)(&priv->lock);
@@ -284,9 +291,15 @@ static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
if (status & ABX8XX_STATUS_WDT)
dev_alert(&client->dev, "watchdog timeout interrupt.\n");
- i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
+ status_flags_clear = status & (ABX8XX_STATUS_AF | ABX8XX_STATUS_WDT);
- return IRQ_HANDLED;
+ if (status_flags_clear) {
+ i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS,
+ status & ~status_flags_clear);
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
}
static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
@@ -942,6 +955,41 @@ static int abx80x_probe(struct i2c_client *client)
i2c_set_clientdata(client, priv);
+ /* Disable unused interrupts */
+ data = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
+ if (data < 0) {
+ dev_err(&client->dev, "Unable to read irq register\n");
+ return -EIO;
+ }
+
+ err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
+ data & ~(ABX8XX_IRQ_EX1E |
+ ABX8XX_IRQ_EX2E |
+ ABX8XX_IRQ_TIE |
+ ABX8XX_IRQ_BLIE));
+ if (err < 0) {
+ dev_err(&client->dev, "Unable to write irq register\n");
+ return -EIO;
+ }
+
+ data = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
+ if (data < 0) {
+ dev_err(&client->dev, "Unable to read Oscillator Control register\n");
+ return -EIO;
+ }
+
+ /* Unlock write access to Oscillator Control Register */
+ if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
+ return -EIO;
+
+ err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC,
+ data & ~(ABX8XX_OSC_ACIE |
+ ABX8XX_OSC_OFIE));
+ if (err < 0) {
+ dev_err(&client->dev, "Unable to write Oscillator Control register\n");
+ return -EIO;
+ }
+
if (abx80x_caps[part].has_wdog) {
err = abx80x_setup_watchdog(priv);
if (err)
--
2.55.0
^ permalink raw reply related [flat|nested] 22+ messages in thread* Re: [PATCH v7 4/9] rtc: abx80x: properly handle shared IRQs
2026-09-16 20:51 ` [PATCH v7 4/9] rtc: abx80x: properly handle shared IRQs Antoni Pokusinski
@ 2026-09-16 21:05 ` sashiko-bot
2026-09-17 18:00 ` Antoni Pokusinski
0 siblings, 1 reply; 22+ messages in thread
From: sashiko-bot @ 2026-09-16 21:05 UTC (permalink / raw)
To: Antoni Pokusinski
Cc: robh, linux-rtc, devicetree, Alexandre Belloni, conor+dt
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] rtc: abx80x: race condition loses interrupts due to flawed W0C status register clearing
--
commit 27cfcb7135851594344aa538f01f8ef1328d2392
Author: Antoni Pokusinski <apokusinski01@gmail.com>
rtc: abx80x: properly handle shared IRQs
This commit updates the abx80x RTC interrupt handler to only return
IRQ_HANDLED and clear the status register when the alarm or watchdog flags
are set. It aims to properly support IRQF_SHARED by returning IRQ_NONE
for unrelated interrupts.
> diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
> --- a/drivers/rtc/rtc-abx80x.c
> +++ b/drivers/rtc/rtc-abx80x.c
[ ... ]
> @@ -284,9 +291,15 @@ static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
> if (status & ABX8XX_STATUS_WDT)
> dev_alert(&client->dev, "watchdog timeout interrupt.\n");
>
> - i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
> + status_flags_clear = status & (ABX8XX_STATUS_AF | ABX8XX_STATUS_WDT);
>
> - return IRQ_HANDLED;
> + if (status_flags_clear) {
> + i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS,
> + status & ~status_flags_clear);
[Severity: High]
Does this logic introduce a race condition that loses late-arriving interrupts
in abx80x_handle_irq()?
Because the ABX8XX_REG_STATUS register is W0C (write-0-to-clear), any bit
written as 0 will be cleared in hardware.
The expression status & ~status_flags_clear forces a 0 for all bits that
were 0 during the initial read. If a new hardware interrupt asserts between
the read and this write, its status bit will be newly set to 1 in hardware.
However, writing back the old status value forces a 0 for that new bit,
silently clearing it and losing the event.
To preserve unhandled or newly asserted bits, the correct write value for a
W0C register is ~status_flags_clear instead.
> + return IRQ_HANDLED;
> + }
> +
> + return IRQ_NONE;
> }
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260916205138.16771-1-apokusinski01@gmail.com?part=4
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH v7 4/9] rtc: abx80x: properly handle shared IRQs
2026-09-16 21:05 ` sashiko-bot
@ 2026-09-17 18:00 ` Antoni Pokusinski
0 siblings, 0 replies; 22+ messages in thread
From: Antoni Pokusinski @ 2026-09-17 18:00 UTC (permalink / raw)
To: sashiko-reviews; +Cc: robh, linux-rtc, devicetree, Alexandre Belloni, conor+dt
On Wed, Sep 16, 2026 at 09:05:27PM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [High] rtc: abx80x: race condition loses interrupts due to flawed W0C status register clearing
> --
>
> commit 27cfcb7135851594344aa538f01f8ef1328d2392
> Author: Antoni Pokusinski <apokusinski01@gmail.com>
>
> rtc: abx80x: properly handle shared IRQs
>
> This commit updates the abx80x RTC interrupt handler to only return
> IRQ_HANDLED and clear the status register when the alarm or watchdog flags
> are set. It aims to properly support IRQF_SHARED by returning IRQ_NONE
> for unrelated interrupts.
>
> > diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
> > --- a/drivers/rtc/rtc-abx80x.c
> > +++ b/drivers/rtc/rtc-abx80x.c
>
> [ ... ]
>
> > @@ -284,9 +291,15 @@ static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
> > if (status & ABX8XX_STATUS_WDT)
> > dev_alert(&client->dev, "watchdog timeout interrupt.\n");
> >
> > - i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
> > + status_flags_clear = status & (ABX8XX_STATUS_AF | ABX8XX_STATUS_WDT);
> >
> > - return IRQ_HANDLED;
> > + if (status_flags_clear) {
> > + i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS,
> > + status & ~status_flags_clear);
>
> [Severity: High]
> Does this logic introduce a race condition that loses late-arriving interrupts
> in abx80x_handle_irq()?
>
> Because the ABX8XX_REG_STATUS register is W0C (write-0-to-clear), any bit
> written as 0 will be cleared in hardware.
>
> The expression status & ~status_flags_clear forces a 0 for all bits that
> were 0 during the initial read. If a new hardware interrupt asserts between
> the read and this write, its status bit will be newly set to 1 in hardware.
> However, writing back the old status value forces a 0 for that new bit,
> silently clearing it and losing the event.
>
> To preserve unhandled or newly asserted bits, the correct write value for a
> W0C register is ~status_flags_clear instead.
>
Not really: if the register bits are written with 1, then during the
next call to `handle_irq()` all the interrupts are reported as pending
(in other words the written ones are preserved).
In particular, when I was testing the alarm interrupt and the written value was
`~status_flags_clear` as sashiko suggests, I was always getting the WDT
bit enabled and hence the alert "watchdog timeout interrupt" was
printed.
> > + return IRQ_HANDLED;
> > + }
> > +
> > + return IRQ_NONE;
> > }
>
> --
> Sashiko AI review · https://sashiko.dev/#/patchset/20260916205138.16771-1-apokusinski01@gmail.com?part=4
^ permalink raw reply [flat|nested] 22+ messages in thread
* [PATCH v7 5/9] rtc: abx80x: add irq to struct abx80x_priv
2026-09-16 20:51 [PATCH v7 0/9] rtc: abx80x: add support for abx81x Antoni Pokusinski
` (3 preceding siblings ...)
2026-09-16 20:51 ` [PATCH v7 4/9] rtc: abx80x: properly handle shared IRQs Antoni Pokusinski
@ 2026-09-16 20:51 ` Antoni Pokusinski
2026-09-16 20:59 ` sashiko-bot
2026-09-16 20:51 ` [PATCH v7 6/9] rtc: abx80x: use regmap instead of I2C specific API Antoni Pokusinski
` (4 subsequent siblings)
9 siblings, 1 reply; 22+ messages in thread
From: Antoni Pokusinski @ 2026-09-16 20:51 UTC (permalink / raw)
To: alexandre.belloni, robh, krzk+dt, conor+dt
Cc: linux-rtc, devicetree, linux-kernel, Antoni Pokusinski
This way the irq number is not tied to the i2c_client and can be
easily accessed also in the case of ABX81X SPI clocks.
Signed-off-by: Antoni Pokusinski <apokusinski01@gmail.com>
---
drivers/rtc/rtc-abx80x.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index 2fd0079b7c51..91844c0d9063 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -135,6 +135,7 @@ struct abx80x_priv {
struct i2c_client *client;
struct watchdog_device wdog;
struct mutex lock;
+ int irq;
};
static int abx80x_write_config_key(struct i2c_client *client, u8 key)
@@ -305,11 +306,12 @@ static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct i2c_client *client = to_i2c_client(dev);
+ struct abx80x_priv *priv = i2c_get_clientdata(client);
unsigned char buf[7];
int irq_mask, err;
- if (client->irq <= 0)
+ if (priv->irq <= 0)
return -EINVAL;
err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
@@ -343,7 +345,7 @@ static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
u8 alarm[6];
int err;
- if (client->irq <= 0)
+ if (priv->irq <= 0)
return -EINVAL;
alarm[0] = 0x0;
@@ -949,6 +951,7 @@ static int abx80x_probe(struct i2c_client *client)
priv->rtc->ops = &abx80x_rtc_ops;
priv->client = client;
+ priv->irq = client->irq;
err = devm_mutex_init(&client->dev, &priv->lock);
if (err)
return err;
@@ -1000,19 +1003,19 @@ static int abx80x_probe(struct i2c_client *client)
if (err)
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,
+ if (priv->irq > 0) {
+ dev_info(&client->dev, "IRQ %d supplied\n", priv->irq);
+ err = devm_request_threaded_irq(&client->dev, priv->irq, NULL,
abx80x_handle_irq,
IRQF_SHARED | IRQF_ONESHOT,
"abx8xx",
client);
if (err) {
dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
- client->irq = 0;
+ priv->irq = 0;
}
}
- if (client->irq <= 0)
+ if (priv->irq <= 0)
clear_bit(RTC_FEATURE_ALARM, priv->rtc->features);
err = rtc_add_group(priv->rtc, &rtc_calib_attr_group);
--
2.55.0
^ permalink raw reply related [flat|nested] 22+ messages in thread* [PATCH v7 6/9] rtc: abx80x: use regmap instead of I2C specific API
2026-09-16 20:51 [PATCH v7 0/9] rtc: abx80x: add support for abx81x Antoni Pokusinski
` (4 preceding siblings ...)
2026-09-16 20:51 ` [PATCH v7 5/9] rtc: abx80x: add irq to struct abx80x_priv Antoni Pokusinski
@ 2026-09-16 20:51 ` Antoni Pokusinski
2026-09-16 21:05 ` sashiko-bot
2026-09-16 20:51 ` [PATCH v7 7/9] rtc: abx80x: replace read-modify-write pattern with regmap helpers Antoni Pokusinski
` (3 subsequent siblings)
9 siblings, 1 reply; 22+ messages in thread
From: Antoni Pokusinski @ 2026-09-16 20:51 UTC (permalink / raw)
To: alexandre.belloni, robh, krzk+dt, conor+dt
Cc: linux-rtc, devicetree, linux-kernel, Antoni Pokusinski
Rework the driver so that it uses regmap_* functions for communication
with the device instead of the i2c_smbus_* API. This way the support for
ABX81X RTCs which use SPI can be added later.
Signed-off-by: Antoni Pokusinski <apokusinski01@gmail.com>
---
drivers/rtc/Kconfig | 1 +
drivers/rtc/rtc-abx80x.c | 395 +++++++++++++++++++++------------------
2 files changed, 213 insertions(+), 183 deletions(-)
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 01def8231873..4d14bcba616e 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -215,6 +215,7 @@ config RTC_DRV_ABEOZ9
config RTC_DRV_ABX80X
tristate "Abracon ABx80x"
select WATCHDOG_CORE if WATCHDOG
+ select REGMAP_I2C
help
If you say yes here you get support for Abracon AB080X and AB180X
families of ultra-low-power battery- and capacitor-backed real-time
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index 91844c0d9063..d41656a4d518 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -17,6 +17,7 @@
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
+#include <linux/regmap.h>
#include <linux/rtc.h>
#include <linux/watchdog.h>
@@ -132,53 +133,55 @@ static struct abx80x_cap abx80x_caps[] = {
struct abx80x_priv {
struct rtc_device *rtc;
- struct i2c_client *client;
+ struct regmap *regmap;
struct watchdog_device wdog;
struct mutex lock;
int irq;
};
-static int abx80x_write_config_key(struct i2c_client *client, u8 key)
+static int abx80x_write_config_key(struct device *dev, u8 key)
{
- if (i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY, key) < 0) {
- dev_err(&client->dev, "Unable to write configuration key\n");
+ struct abx80x_priv *priv = dev_get_drvdata(dev);
+
+ if (regmap_write(priv->regmap, ABX8XX_REG_CFG_KEY, key) < 0) {
+ dev_err(dev, "Unable to write configuration key\n");
return -EIO;
}
return 0;
}
-static int abx80x_is_rc_mode(struct i2c_client *client)
+static int abx80x_is_rc_mode(struct device *dev)
{
- int flags = 0;
+ struct abx80x_priv *priv = dev_get_drvdata(dev);
+ unsigned int flags = 0;
+ int err;
- flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
- if (flags < 0) {
- dev_err(&client->dev,
- "Failed to read autocalibration attribute\n");
- return flags;
+ err = regmap_read(priv->regmap, ABX8XX_REG_OSS, &flags);
+ if (err < 0) {
+ dev_err(dev, "Failed to read autocalibration attribute\n");
+ return err;
}
return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
}
-static int abx80x_enable_trickle_charger(struct i2c_client *client,
- u8 trickle_cfg)
+static int abx80x_enable_trickle_charger(struct device *dev, u8 trickle_cfg)
{
+ struct abx80x_priv *priv = dev_get_drvdata(dev);
int err;
/*
* Write the configuration key register to enable access to the Trickle
* register
*/
- if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_MISC) < 0)
+ if (abx80x_write_config_key(dev, ABX8XX_CFG_KEY_MISC) < 0)
return -EIO;
- err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
- ABX8XX_TRICKLE_CHARGE_ENABLE |
- trickle_cfg);
+ err = regmap_write(priv->regmap, ABX8XX_REG_TRICKLE,
+ ABX8XX_TRICKLE_CHARGE_ENABLE | trickle_cfg);
if (err < 0) {
- dev_err(&client->dev, "Unable to write trickle register\n");
+ dev_err(dev, "Unable to write trickle register\n");
return -EIO;
}
@@ -187,19 +190,20 @@ static int abx80x_enable_trickle_charger(struct i2c_client *client,
static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
- struct i2c_client *client = to_i2c_client(dev);
+ struct abx80x_priv *priv = dev_get_drvdata(dev);
unsigned char buf[8];
- int err, flags, rc_mode = 0;
+ unsigned int flags;
+ int err, rc_mode = 0;
/* Read the Oscillator Failure only in XT mode */
- rc_mode = abx80x_is_rc_mode(client);
+ rc_mode = abx80x_is_rc_mode(dev);
if (rc_mode < 0)
return rc_mode;
if (!rc_mode) {
- flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
- if (flags < 0)
- return flags;
+ err = regmap_read(priv->regmap, ABX8XX_REG_OSS, &flags);
+ if (err < 0)
+ return err;
if (flags & ABX8XX_OSS_OF) {
dev_err(dev, "Oscillator failure, data is invalid.\n");
@@ -207,10 +211,9 @@ static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
}
}
- err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
- sizeof(buf), buf);
+ err = regmap_bulk_read(priv->regmap, ABX8XX_REG_HTH, buf, sizeof(buf));
if (err < 0) {
- dev_err(&client->dev, "Unable to read date\n");
+ dev_err(dev, "Unable to read date\n");
return -EIO;
}
@@ -227,10 +230,10 @@ static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
- struct i2c_client *client = to_i2c_client(dev);
- struct abx80x_priv *priv = i2c_get_clientdata(client);
+ struct abx80x_priv *priv = dev_get_drvdata(dev);
unsigned char buf[8];
- int err, flags;
+ unsigned int flags;
+ int err;
if (tm->tm_year < 100)
return -EINVAL;
@@ -246,22 +249,22 @@ static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
guard(mutex)(&priv->lock);
- err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
- sizeof(buf), buf);
+ err = regmap_bulk_write(priv->regmap, ABX8XX_REG_HTH, buf,
+ sizeof(buf));
if (err < 0) {
- dev_err(&client->dev, "Unable to write to date registers\n");
+ dev_err(dev, "Unable to write to date registers\n");
return -EIO;
}
/* Clear the OF bit of Oscillator Status Register */
- flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
- if (flags < 0)
- return flags;
+ err = regmap_read(priv->regmap, ABX8XX_REG_OSS, &flags);
+ if (err < 0)
+ return err;
- err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS,
- flags & ~ABX8XX_OSS_OF);
+ err = regmap_write(priv->regmap, ABX8XX_REG_OSS,
+ flags & ~ABX8XX_OSS_OF);
if (err < 0) {
- dev_err(&client->dev, "Unable to write oscillator status register\n");
+ dev_err(dev, "Unable to write oscillator status register\n");
return err;
}
@@ -270,16 +273,16 @@ static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
{
- struct i2c_client *client = dev_id;
- struct abx80x_priv *priv = i2c_get_clientdata(client);
+ struct device *dev = dev_id;
+ struct abx80x_priv *priv = dev_get_drvdata(dev);
struct rtc_device *rtc = priv->rtc;
- unsigned int status_flags_clear;
- int status;
+ unsigned int status, status_flags_clear;
+ int err;
guard(mutex)(&priv->lock);
- status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
- if (status < 0)
+ err = regmap_read(priv->regmap, ABX8XX_REG_STATUS, &status);
+ if (err < 0)
return IRQ_NONE;
if (status & ABX8XX_STATUS_AF)
@@ -290,13 +293,13 @@ static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
* reset kicks in.
*/
if (status & ABX8XX_STATUS_WDT)
- dev_alert(&client->dev, "watchdog timeout interrupt.\n");
+ dev_alert(dev, "watchdog timeout interrupt.\n");
status_flags_clear = status & (ABX8XX_STATUS_AF | ABX8XX_STATUS_WDT);
if (status_flags_clear) {
- i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS,
- status & ~status_flags_clear);
+ regmap_write(priv->regmap, ABX8XX_REG_STATUS,
+ status & ~status_flags_clear);
return IRQ_HANDLED;
}
@@ -305,25 +308,22 @@ static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
- struct i2c_client *client = to_i2c_client(dev);
- struct abx80x_priv *priv = i2c_get_clientdata(client);
+ struct abx80x_priv *priv = dev_get_drvdata(dev);
unsigned char buf[7];
- int irq_mask, err;
+ unsigned int irq_mask;
+ int err;
if (priv->irq <= 0)
return -EINVAL;
- err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
- sizeof(buf), buf);
- if (err < 0)
+ err = regmap_bulk_read(priv->regmap, ABX8XX_REG_ASC, buf, sizeof(buf));
+ if (err)
return err;
- if (err < ARRAY_SIZE(buf))
- return -EIO;
- irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
- if (irq_mask < 0)
- return irq_mask;
+ err = regmap_read(priv->regmap, ABX8XX_REG_IRQ, &irq_mask);
+ if (err < 0)
+ return err;
t->time.tm_sec = bcd2bin(buf[0] & 0x7F);
t->time.tm_min = bcd2bin(buf[1] & 0x7F);
@@ -340,8 +340,7 @@ static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
- struct i2c_client *client = to_i2c_client(dev);
- struct abx80x_priv *priv = i2c_get_clientdata(client);
+ struct abx80x_priv *priv = dev_get_drvdata(dev);
u8 alarm[6];
int err;
@@ -357,17 +356,16 @@ static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
guard(mutex)(&priv->lock);
- err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
- sizeof(alarm), alarm);
+ err = regmap_bulk_write(priv->regmap, ABX8XX_REG_AHTH,
+ alarm, sizeof(alarm));
if (err < 0) {
- dev_err(&client->dev, "Unable to write alarm registers\n");
+ dev_err(dev, "Unable to write alarm registers\n");
return -EIO;
}
if (t->enabled) {
- err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
- (ABX8XX_IRQ_IM_1_4 |
- ABX8XX_IRQ_AIE));
+ err = regmap_write(priv->regmap, ABX8XX_REG_IRQ,
+ ABX8XX_IRQ_IM_1_4 | ABX8XX_IRQ_AIE);
if (err)
return err;
}
@@ -378,9 +376,9 @@ static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
static int abx80x_rtc_set_autocalibration(struct device *dev,
int autocalibration)
{
- struct i2c_client *client = to_i2c_client(dev);
- struct abx80x_priv *priv = i2c_get_clientdata(client);
- int retval, flags = 0;
+ struct abx80x_priv *priv = dev_get_drvdata(dev);
+ unsigned int flags = 0;
+ int retval;
if ((autocalibration != 0) && (autocalibration != 1024) &&
(autocalibration != 512)) {
@@ -390,9 +388,9 @@ static int abx80x_rtc_set_autocalibration(struct device *dev,
guard(mutex)(&priv->lock);
- flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
- if (flags < 0)
- return flags;
+ retval = regmap_read(priv->regmap, ABX8XX_REG_OSC, &flags);
+ if (retval < 0)
+ return retval;
if (autocalibration == 0) {
flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
@@ -406,22 +404,23 @@ static int abx80x_rtc_set_autocalibration(struct device *dev,
}
/* Unlock write access to Oscillator Control Register */
- if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
+ if (abx80x_write_config_key(dev, ABX8XX_CFG_KEY_OSC) < 0)
return -EIO;
- retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
+ retval = regmap_write(priv->regmap, ABX8XX_REG_OSC, flags);
return retval;
}
static int abx80x_rtc_get_autocalibration(struct device *dev)
{
- struct i2c_client *client = to_i2c_client(dev);
- int flags = 0, autocalibration;
+ struct abx80x_priv *priv = dev_get_drvdata(dev);
+ unsigned int flags = 0;
+ int autocalibration, err;
- flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
- if (flags < 0)
- return flags;
+ err = regmap_read(priv->regmap, ABX8XX_REG_OSC, &flags);
+ if (err < 0)
+ return err;
if (flags & ABX8XX_OSC_ACAL_512)
autocalibration = 512;
@@ -472,9 +471,9 @@ static ssize_t oscillator_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
- struct i2c_client *client = to_i2c_client(dev->parent);
- struct abx80x_priv *priv = i2c_get_clientdata(client);
- int retval, flags, rc_mode = 0;
+ struct abx80x_priv *priv = dev_get_drvdata(dev->parent);
+ int retval, rc_mode = 0;
+ unsigned int flags;
if (strncmp(buf, "rc", 2) == 0) {
rc_mode = 1;
@@ -487,9 +486,9 @@ static ssize_t oscillator_store(struct device *dev,
guard(mutex)(&priv->lock);
- flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
- if (flags < 0)
- return flags;
+ retval = regmap_read(priv->regmap, ABX8XX_REG_OSC, &flags);
+ if (retval < 0)
+ return retval;
if (rc_mode == 0)
flags &= ~(ABX8XX_OSC_OSEL);
@@ -497,10 +496,10 @@ static ssize_t oscillator_store(struct device *dev,
flags |= (ABX8XX_OSC_OSEL);
/* Unlock write access on Oscillator Control register */
- if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
+ if (abx80x_write_config_key(dev->parent, ABX8XX_CFG_KEY_OSC) < 0)
return -EIO;
- retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
+ retval = regmap_write(priv->regmap, ABX8XX_REG_OSC, flags);
if (retval < 0) {
dev_err(dev, "Failed to write Oscillator Control register\n");
return retval;
@@ -513,9 +512,8 @@ static ssize_t oscillator_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int rc_mode = 0;
- struct i2c_client *client = to_i2c_client(dev->parent);
- rc_mode = abx80x_is_rc_mode(client);
+ rc_mode = abx80x_is_rc_mode(dev->parent);
if (rc_mode < 0) {
dev_err(dev, "Failed to read RTC oscillator selection\n");
@@ -543,33 +541,31 @@ static const struct attribute_group rtc_calib_attr_group = {
static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
- struct i2c_client *client = to_i2c_client(dev);
- struct abx80x_priv *priv = i2c_get_clientdata(client);
+ struct abx80x_priv *priv = dev_get_drvdata(dev);
int err;
guard(mutex)(&priv->lock);
if (enabled)
- err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
- (ABX8XX_IRQ_IM_1_4 |
- ABX8XX_IRQ_AIE));
+ err = regmap_write(priv->regmap, ABX8XX_REG_IRQ,
+ ABX8XX_IRQ_IM_1_4 | ABX8XX_IRQ_AIE);
else
- err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
- ABX8XX_IRQ_IM_1_4);
+ err = regmap_write(priv->regmap, ABX8XX_REG_IRQ,
+ ABX8XX_IRQ_IM_1_4);
return err;
}
static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
- struct i2c_client *client = to_i2c_client(dev);
- struct abx80x_priv *priv = i2c_get_clientdata(client);
- int status, tmp;
+ struct abx80x_priv *priv = dev_get_drvdata(dev);
+ unsigned int status;
+ int err, tmp;
switch (cmd) {
case RTC_VL_READ:
- status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
- if (status < 0)
- return status;
+ err = regmap_read(priv->regmap, ABX8XX_REG_STATUS, &status);
+ if (err < 0)
+ return err;
tmp = status & ABX8XX_STATUS_BLF ? RTC_VL_BACKUP_LOW : 0;
@@ -577,16 +573,15 @@ static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
case RTC_VL_CLR:
scoped_guard(mutex, &priv->lock) {
- status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
- if (status < 0)
- return status;
+ err = regmap_read(priv->regmap, ABX8XX_REG_STATUS, &status);
+ if (err < 0)
+ return err;
status &= ~ABX8XX_STATUS_BLF;
- tmp = i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS,
- status);
- if (tmp < 0)
- return tmp;
+ err = regmap_write(priv->regmap, ABX8XX_REG_STATUS, status);
+ if (err < 0)
+ return err;
}
return 0;
@@ -605,9 +600,9 @@ static const struct rtc_class_ops abx80x_rtc_ops = {
.ioctl = abx80x_ioctl,
};
-static int abx80x_dt_trickle_cfg(struct i2c_client *client)
+static int abx80x_dt_trickle_cfg(struct device *dev)
{
- struct device_node *np = client->dev.of_node;
+ struct device_node *np = dev->of_node;
const char *diode;
int trickle_cfg = 0;
int i, ret;
@@ -622,7 +617,7 @@ static int abx80x_dt_trickle_cfg(struct i2c_client *client)
} else if (!strcmp(diode, "schottky")) {
trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
} else {
- dev_dbg(&client->dev, "Invalid tc-diode value: %s\n", diode);
+ dev_dbg(dev, "Invalid tc-diode value: %s\n", diode);
return -EINVAL;
}
@@ -635,7 +630,7 @@ static int abx80x_dt_trickle_cfg(struct i2c_client *client)
break;
if (i == sizeof(trickle_resistors)) {
- dev_dbg(&client->dev, "Invalid tc-resistor value: %u\n", tmp);
+ dev_dbg(dev, "Invalid tc-resistor value: %u\n", tmp);
return -EINVAL;
}
@@ -662,7 +657,7 @@ static int __abx80x_wdog_set_timeout(struct watchdog_device *wdog,
* Writing any timeout to the WDT register resets the watchdog timer.
* Writing 0 disables it.
*/
- return i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_WDT, val);
+ return regmap_write(priv->regmap, ABX8XX_REG_WDT, val);
}
static int abx80x_wdog_set_timeout(struct watchdog_device *wdog,
@@ -707,9 +702,11 @@ static const struct watchdog_ops abx80x_wdog_ops = {
.set_timeout = abx80x_wdog_set_timeout,
};
-static int abx80x_setup_watchdog(struct abx80x_priv *priv)
+static int abx80x_setup_watchdog(struct device *dev)
{
- priv->wdog.parent = &priv->client->dev;
+ struct abx80x_priv *priv = dev_get_drvdata(dev);
+
+ priv->wdog.parent = dev;
priv->wdog.ops = &abx80x_wdog_ops;
priv->wdog.info = &abx80x_wdog_info;
priv->wdog.min_timeout = 1;
@@ -718,10 +715,10 @@ static int abx80x_setup_watchdog(struct abx80x_priv *priv)
watchdog_set_drvdata(&priv->wdog, priv);
- return devm_watchdog_register_device(&priv->client->dev, &priv->wdog);
+ return devm_watchdog_register_device(dev, &priv->wdog);
}
#else
-static int abx80x_setup_watchdog(struct abx80x_priv *priv)
+static int abx80x_setup_watchdog(struct device *dev)
{
return 0;
}
@@ -733,33 +730,29 @@ static int abx80x_nvmem_xfer(struct abx80x_priv *priv, unsigned int offset,
int ret;
while (bytes) {
- u8 extram, reg, len, lower, upper;
+ u8 reg, len, lower, upper;
lower = FIELD_GET(NVMEM_ADDR_LOWER, offset);
upper = FIELD_GET(NVMEM_ADDR_UPPER, offset);
- extram = FIELD_PREP(ABX8XX_EXTRAM_XADS, upper);
reg = ABX8XX_SRAM_BASE + lower;
len = min(lower + bytes, (size_t)ABX8XX_SRAM_WIN_SIZE) - lower;
len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
guard(mutex)(&priv->lock);
- ret = i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_EXTRAM,
- extram);
+ ret = regmap_update_bits(priv->regmap, ABX8XX_REG_EXTRAM,
+ ABX8XX_EXTRAM_XADS, upper);
if (ret)
return ret;
if (write) {
- ret = i2c_smbus_write_i2c_block_data(priv->client, reg,
- len, val);
+ ret = regmap_bulk_write(priv->regmap, reg, val, len);
if (ret)
return ret;
} else {
- ret = i2c_smbus_read_i2c_block_data(priv->client, reg,
- len, val);
- if (ret <= 0)
- return ret ? ret : -EIO;
- len = ret;
+ ret = regmap_bulk_read(priv->regmap, reg, val, len);
+ if (ret)
+ return ret;
}
offset += len;
@@ -795,6 +788,38 @@ static int abx80x_setup_nvmem(struct abx80x_priv *priv)
return devm_rtc_nvmem_register(priv->rtc, &config);
}
+static const struct regmap_range abx80x_no_read_ranges[] = {
+ regmap_reg_range(0x1e, 0x1e),
+ regmap_reg_range(0x22, 0x25),
+ regmap_reg_range(0x31, 0x3e),
+};
+
+static const struct regmap_range abx80x_no_write_ranges[] = {
+ regmap_reg_range(0x1e, 0x1e),
+ regmap_reg_range(0x22, 0x25),
+ regmap_reg_range(ABX8XX_REG_ID0, ABX8XX_REG_ID0 + 6),
+ regmap_reg_range(0x31, 0x3e),
+};
+
+static const struct regmap_access_table abx80x_read_table = {
+ .no_ranges = abx80x_no_read_ranges,
+ .n_no_ranges = ARRAY_SIZE(abx80x_no_read_ranges),
+};
+
+static const struct regmap_access_table abx80x_write_table = {
+ .no_ranges = abx80x_no_write_ranges,
+ .n_no_ranges = ARRAY_SIZE(abx80x_no_write_ranges),
+};
+
+static const struct regmap_config abx80x_regmap_config_i2c = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = ABX8XX_SRAM_BASE + ABX8XX_SRAM_WIN_SIZE - 1,
+
+ .rd_table = &abx80x_read_table,
+ .wr_table = &abx80x_write_table,
+};
+
static const struct i2c_device_id abx80x_id[] = {
{ .name = "abx80x", .driver_data = ABX80X },
{ .name = "ab0801", .driver_data = AB0801 },
@@ -812,9 +837,11 @@ MODULE_DEVICE_TABLE(i2c, abx80x_id);
static int abx80x_probe(struct i2c_client *client)
{
+ struct regmap *regmap;
struct device_node *np = client->dev.of_node;
struct abx80x_priv *priv;
- int i, data, err, trickle_cfg = -EINVAL;
+ int i, err, trickle_cfg = -EINVAL;
+ unsigned int data;
char buf[7];
unsigned int part = (uintptr_t)i2c_get_match_data(client);
unsigned int partnumber;
@@ -826,8 +853,30 @@ static int abx80x_probe(struct i2c_client *client)
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
- err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
- sizeof(buf), buf);
+ regmap = devm_regmap_init_i2c(client, &abx80x_regmap_config_i2c);
+ if (IS_ERR(regmap)) {
+ dev_err(&client->dev, "Unable to allocate regmap\n");
+ return PTR_ERR(regmap);
+ }
+
+ priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
+ if (priv == NULL)
+ return -ENOMEM;
+
+ priv->rtc = devm_rtc_allocate_device(&client->dev);
+ if (IS_ERR(priv->rtc))
+ return PTR_ERR(priv->rtc);
+
+ priv->rtc->ops = &abx80x_rtc_ops;
+ priv->irq = client->irq;
+ priv->regmap = regmap;
+ err = devm_mutex_init(&client->dev, &priv->lock);
+ if (err)
+ return err;
+
+ dev_set_drvdata(&client->dev, priv);
+
+ err = regmap_bulk_read(regmap, ABX8XX_REG_ID0, buf, sizeof(buf));
if (err < 0) {
dev_err(&client->dev, "Unable to read partnumber\n");
return -EIO;
@@ -842,16 +891,14 @@ static int abx80x_probe(struct i2c_client *client)
dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
partnumber, majrev, minrev, lot, wafer, uid);
- data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
- if (data < 0) {
+ err = regmap_read(regmap, ABX8XX_REG_CTRL1, &data);
+ if (err < 0) {
dev_err(&client->dev, "Unable to read control register\n");
return -EIO;
}
- err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
- ((data & ~(ABX8XX_CTRL_12_24 |
- ABX8XX_CTRL_ARST)) |
- ABX8XX_CTRL_WRITE));
+ err = regmap_write(regmap, ABX8XX_REG_CTRL1,
+ (data & ~(ABX8XX_CTRL_12_24 | ABX8XX_CTRL_ARST)) | ABX8XX_CTRL_WRITE);
if (err < 0) {
dev_err(&client->dev, "Unable to write control register\n");
return -EIO;
@@ -865,15 +912,15 @@ static int abx80x_probe(struct i2c_client *client)
* register is set. RV-1805-C3 datasheet indicates that
* the bit should be cleared in section 11h - Control2.
*/
- data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL2);
- if (data < 0) {
+ err = regmap_read(regmap, ABX8XX_REG_CTRL2, &data);
+ if (err < 0) {
dev_err(&client->dev,
"Unable to read control2 register\n");
return -EIO;
}
- err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL2,
- data & ~ABX8XX_CTRL2_RSVD);
+ err = regmap_write(regmap, ABX8XX_REG_CTRL2,
+ data & ~ABX8XX_CTRL2_RSVD);
if (err < 0) {
dev_err(&client->dev,
"Unable to write control2 register\n");
@@ -885,8 +932,8 @@ static int abx80x_probe(struct i2c_client *client)
* 10pin package and the EXTI input is not present.
* Disable it to avoid leakage.
*/
- data = i2c_smbus_read_byte_data(client, ABX8XX_REG_OUT_CTRL);
- if (data < 0) {
+ err = regmap_read(regmap, ABX8XX_REG_OUT_CTRL, &data);
+ if (err < 0) {
dev_err(&client->dev,
"Unable to read output control register\n");
return -EIO;
@@ -896,11 +943,11 @@ static int abx80x_probe(struct i2c_client *client)
* Write the configuration key register to enable access to
* the config2 register
*/
- if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_MISC) < 0)
+ if (abx80x_write_config_key(&client->dev, ABX8XX_CFG_KEY_MISC) < 0)
return -EIO;
- err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OUT_CTRL,
- data | ABX8XX_OUT_CTRL_EXDS);
+ err = regmap_write(regmap, ABX8XX_REG_OUT_CTRL,
+ data | ABX8XX_OUT_CTRL_EXDS);
if (err < 0) {
dev_err(&client->dev,
"Unable to write output control register\n");
@@ -928,55 +975,37 @@ static int abx80x_probe(struct i2c_client *client)
}
if (np && abx80x_caps[part].has_tc)
- trickle_cfg = abx80x_dt_trickle_cfg(client);
+ trickle_cfg = abx80x_dt_trickle_cfg(&client->dev);
if (trickle_cfg > 0) {
dev_info(&client->dev, "Enabling trickle charger: %02x\n",
trickle_cfg);
- abx80x_enable_trickle_charger(client, trickle_cfg);
+ abx80x_enable_trickle_charger(&client->dev, trickle_cfg);
}
- err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
- BIT(2));
+ err = regmap_write(regmap, ABX8XX_REG_CD_TIMER_CTL, BIT(2));
if (err)
return err;
- priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
- if (priv == NULL)
- return -ENOMEM;
-
- priv->rtc = devm_rtc_allocate_device(&client->dev);
- if (IS_ERR(priv->rtc))
- return PTR_ERR(priv->rtc);
-
- priv->rtc->ops = &abx80x_rtc_ops;
- priv->client = client;
- priv->irq = client->irq;
- err = devm_mutex_init(&client->dev, &priv->lock);
- if (err)
- return err;
-
- i2c_set_clientdata(client, priv);
-
/* Disable unused interrupts */
- data = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
- if (data < 0) {
+ err = regmap_read(regmap, ABX8XX_REG_IRQ, &data);
+ if (err < 0) {
dev_err(&client->dev, "Unable to read irq register\n");
return -EIO;
}
- err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
- data & ~(ABX8XX_IRQ_EX1E |
- ABX8XX_IRQ_EX2E |
- ABX8XX_IRQ_TIE |
- ABX8XX_IRQ_BLIE));
+ err = regmap_write(regmap, ABX8XX_REG_IRQ,
+ data & ~(ABX8XX_IRQ_EX1E |
+ ABX8XX_IRQ_EX2E |
+ ABX8XX_IRQ_TIE |
+ ABX8XX_IRQ_BLIE));
if (err < 0) {
dev_err(&client->dev, "Unable to write irq register\n");
return -EIO;
}
- data = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
- if (data < 0) {
+ err = regmap_read(regmap, ABX8XX_REG_OSC, &data);
+ if (err < 0) {
dev_err(&client->dev, "Unable to read Oscillator Control register\n");
return -EIO;
}
@@ -985,16 +1014,16 @@ static int abx80x_probe(struct i2c_client *client)
if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
return -EIO;
- err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC,
- data & ~(ABX8XX_OSC_ACIE |
- ABX8XX_OSC_OFIE));
+ err = regmap_write(regmap, ABX8XX_REG_OSC,
+ data & ~(ABX8XX_OSC_ACIE |
+ ABX8XX_OSC_OFIE));
if (err < 0) {
dev_err(&client->dev, "Unable to write Oscillator Control register\n");
return -EIO;
}
if (abx80x_caps[part].has_wdog) {
- err = abx80x_setup_watchdog(priv);
+ err = abx80x_setup_watchdog(&client->dev);
if (err)
return err;
}
@@ -1009,7 +1038,7 @@ static int abx80x_probe(struct i2c_client *client)
abx80x_handle_irq,
IRQF_SHARED | IRQF_ONESHOT,
"abx8xx",
- client);
+ &client->dev);
if (err) {
dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
priv->irq = 0;
--
2.55.0
^ permalink raw reply related [flat|nested] 22+ messages in thread* [PATCH v7 7/9] rtc: abx80x: replace read-modify-write pattern with regmap helpers
2026-09-16 20:51 [PATCH v7 0/9] rtc: abx80x: add support for abx81x Antoni Pokusinski
` (5 preceding siblings ...)
2026-09-16 20:51 ` [PATCH v7 6/9] rtc: abx80x: use regmap instead of I2C specific API Antoni Pokusinski
@ 2026-09-16 20:51 ` Antoni Pokusinski
2026-09-16 21:05 ` sashiko-bot
2026-09-16 20:51 ` [PATCH v7 8/9] rtc: abx80x: create abx80x_i2c_probe() Antoni Pokusinski
` (2 subsequent siblings)
9 siblings, 1 reply; 22+ messages in thread
From: Antoni Pokusinski @ 2026-09-16 20:51 UTC (permalink / raw)
To: alexandre.belloni, robh, krzk+dt, conor+dt
Cc: linux-rtc, devicetree, linux-kernel, Antoni Pokusinski
Before introducing the regmap usage in the driver, updating specific
bits of a register was performed using the read-modify-write pattern.
Now, the functions regmap_update_bits() and regmap_write_bits() can
be used to simplify the code.
Signed-off-by: Antoni Pokusinski <apokusinski01@gmail.com>
---
drivers/rtc/rtc-abx80x.c | 134 ++++++++++-----------------------------
1 file changed, 34 insertions(+), 100 deletions(-)
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index d41656a4d518..53fc788cbf96 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -232,7 +232,6 @@ static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct abx80x_priv *priv = dev_get_drvdata(dev);
unsigned char buf[8];
- unsigned int flags;
int err;
if (tm->tm_year < 100)
@@ -257,18 +256,11 @@ static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
}
/* Clear the OF bit of Oscillator Status Register */
- err = regmap_read(priv->regmap, ABX8XX_REG_OSS, &flags);
+ err = regmap_update_bits(priv->regmap, ABX8XX_REG_OSS, ABX8XX_OSS_OF, 0);
if (err < 0)
- return err;
-
- err = regmap_write(priv->regmap, ABX8XX_REG_OSS,
- flags & ~ABX8XX_OSS_OF);
- if (err < 0) {
dev_err(dev, "Unable to write oscillator status register\n");
- return err;
- }
- return 0;
+ return err;
}
static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
@@ -378,7 +370,6 @@ static int abx80x_rtc_set_autocalibration(struct device *dev,
{
struct abx80x_priv *priv = dev_get_drvdata(dev);
unsigned int flags = 0;
- int retval;
if ((autocalibration != 0) && (autocalibration != 1024) &&
(autocalibration != 512)) {
@@ -386,12 +377,6 @@ static int abx80x_rtc_set_autocalibration(struct device *dev,
return -EINVAL;
}
- guard(mutex)(&priv->lock);
-
- retval = regmap_read(priv->regmap, ABX8XX_REG_OSC, &flags);
- if (retval < 0)
- return retval;
-
if (autocalibration == 0) {
flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
} else if (autocalibration == 1024) {
@@ -403,13 +388,15 @@ static int abx80x_rtc_set_autocalibration(struct device *dev,
flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
}
+ guard(mutex)(&priv->lock);
+
/* Unlock write access to Oscillator Control Register */
if (abx80x_write_config_key(dev, ABX8XX_CFG_KEY_OSC) < 0)
return -EIO;
- retval = regmap_write(priv->regmap, ABX8XX_REG_OSC, flags);
-
- return retval;
+ return regmap_write_bits(priv->regmap, ABX8XX_REG_OSC,
+ ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512,
+ flags);
}
static int abx80x_rtc_get_autocalibration(struct device *dev)
@@ -473,7 +460,6 @@ static ssize_t oscillator_store(struct device *dev,
{
struct abx80x_priv *priv = dev_get_drvdata(dev->parent);
int retval, rc_mode = 0;
- unsigned int flags;
if (strncmp(buf, "rc", 2) == 0) {
rc_mode = 1;
@@ -486,24 +472,14 @@ static ssize_t oscillator_store(struct device *dev,
guard(mutex)(&priv->lock);
- retval = regmap_read(priv->regmap, ABX8XX_REG_OSC, &flags);
- if (retval < 0)
- return retval;
-
- if (rc_mode == 0)
- flags &= ~(ABX8XX_OSC_OSEL);
- else
- flags |= (ABX8XX_OSC_OSEL);
-
/* Unlock write access on Oscillator Control register */
if (abx80x_write_config_key(dev->parent, ABX8XX_CFG_KEY_OSC) < 0)
return -EIO;
- retval = regmap_write(priv->regmap, ABX8XX_REG_OSC, flags);
- if (retval < 0) {
+ retval = regmap_write_bits(priv->regmap, ABX8XX_REG_OSC, ABX8XX_OSC_OSEL,
+ rc_mode == 0 ? 0 : (ABX8XX_OSC_OSEL));
+ if (retval < 0)
dev_err(dev, "Failed to write Oscillator Control register\n");
- return retval;
- }
return retval ? retval : count;
}
@@ -573,18 +549,11 @@ static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
case RTC_VL_CLR:
scoped_guard(mutex, &priv->lock) {
- err = regmap_read(priv->regmap, ABX8XX_REG_STATUS, &status);
- if (err < 0)
- return err;
-
- status &= ~ABX8XX_STATUS_BLF;
-
- err = regmap_write(priv->regmap, ABX8XX_REG_STATUS, status);
- if (err < 0)
- return err;
+ err = regmap_update_bits(priv->regmap, ABX8XX_REG_STATUS,
+ ABX8XX_STATUS_BLF, 0);
}
- return 0;
+ return err;
default:
return -ENOIOCTLCMD;
@@ -841,7 +810,6 @@ static int abx80x_probe(struct i2c_client *client)
struct device_node *np = client->dev.of_node;
struct abx80x_priv *priv;
int i, err, trickle_cfg = -EINVAL;
- unsigned int data;
char buf[7];
unsigned int part = (uintptr_t)i2c_get_match_data(client);
unsigned int partnumber;
@@ -891,14 +859,9 @@ static int abx80x_probe(struct i2c_client *client)
dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
partnumber, majrev, minrev, lot, wafer, uid);
- err = regmap_read(regmap, ABX8XX_REG_CTRL1, &data);
- if (err < 0) {
- dev_err(&client->dev, "Unable to read control register\n");
- return -EIO;
- }
-
- err = regmap_write(regmap, ABX8XX_REG_CTRL1,
- (data & ~(ABX8XX_CTRL_12_24 | ABX8XX_CTRL_ARST)) | ABX8XX_CTRL_WRITE);
+ err = regmap_update_bits(regmap, ABX8XX_REG_CTRL1,
+ ABX8XX_CTRL_12_24 | ABX8XX_CTRL_ARST | ABX8XX_CTRL_WRITE,
+ ABX8XX_CTRL_WRITE);
if (err < 0) {
dev_err(&client->dev, "Unable to write control register\n");
return -EIO;
@@ -912,30 +875,10 @@ static int abx80x_probe(struct i2c_client *client)
* register is set. RV-1805-C3 datasheet indicates that
* the bit should be cleared in section 11h - Control2.
*/
- err = regmap_read(regmap, ABX8XX_REG_CTRL2, &data);
- if (err < 0) {
- dev_err(&client->dev,
- "Unable to read control2 register\n");
- return -EIO;
- }
-
- err = regmap_write(regmap, ABX8XX_REG_CTRL2,
- data & ~ABX8XX_CTRL2_RSVD);
- if (err < 0) {
- dev_err(&client->dev,
- "Unable to write control2 register\n");
- return -EIO;
- }
-
- /*
- * Avoid extra power leakage. The RV1805 uses smaller
- * 10pin package and the EXTI input is not present.
- * Disable it to avoid leakage.
- */
- err = regmap_read(regmap, ABX8XX_REG_OUT_CTRL, &data);
+ err = regmap_update_bits(regmap, ABX8XX_REG_CTRL2,
+ ABX8XX_CTRL2_RSVD, 0);
if (err < 0) {
- dev_err(&client->dev,
- "Unable to read output control register\n");
+ dev_err(&client->dev, "Unable to write control2 register\n");
return -EIO;
}
@@ -946,8 +889,14 @@ static int abx80x_probe(struct i2c_client *client)
if (abx80x_write_config_key(&client->dev, ABX8XX_CFG_KEY_MISC) < 0)
return -EIO;
- err = regmap_write(regmap, ABX8XX_REG_OUT_CTRL,
- data | ABX8XX_OUT_CTRL_EXDS);
+ /*
+ * Avoid extra power leakage. The RV1805 uses smaller
+ * 10pin package and the EXTI input is not present.
+ * Disable it to avoid leakage.
+ */
+ err = regmap_write_bits(regmap, ABX8XX_REG_OUT_CTRL,
+ ABX8XX_OUT_CTRL_EXDS,
+ ABX8XX_OUT_CTRL_EXDS);
if (err < 0) {
dev_err(&client->dev,
"Unable to write output control register\n");
@@ -988,25 +937,11 @@ static int abx80x_probe(struct i2c_client *client)
return err;
/* Disable unused interrupts */
- err = regmap_read(regmap, ABX8XX_REG_IRQ, &data);
- if (err < 0) {
- dev_err(&client->dev, "Unable to read irq register\n");
- return -EIO;
- }
-
- err = regmap_write(regmap, ABX8XX_REG_IRQ,
- data & ~(ABX8XX_IRQ_EX1E |
- ABX8XX_IRQ_EX2E |
- ABX8XX_IRQ_TIE |
- ABX8XX_IRQ_BLIE));
- if (err < 0) {
- dev_err(&client->dev, "Unable to write irq register\n");
- return -EIO;
- }
-
- err = regmap_read(regmap, ABX8XX_REG_OSC, &data);
+ err = regmap_update_bits(regmap, ABX8XX_REG_IRQ,
+ ABX8XX_IRQ_EX1E | ABX8XX_IRQ_EX2E |
+ ABX8XX_IRQ_TIE | ABX8XX_IRQ_BLIE, 0);
if (err < 0) {
- dev_err(&client->dev, "Unable to read Oscillator Control register\n");
+ dev_err(&client->dev, "Unable to update irq register\n");
return -EIO;
}
@@ -1014,11 +949,10 @@ static int abx80x_probe(struct i2c_client *client)
if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
return -EIO;
- err = regmap_write(regmap, ABX8XX_REG_OSC,
- data & ~(ABX8XX_OSC_ACIE |
- ABX8XX_OSC_OFIE));
+ err = regmap_write_bits(regmap, ABX8XX_REG_OSC,
+ ABX8XX_OSC_ACIE | ABX8XX_OSC_OFIE, 0);
if (err < 0) {
- dev_err(&client->dev, "Unable to write Oscillator Control register\n");
+ dev_err(&client->dev, "Unable to update Oscillator Control register\n");
return -EIO;
}
--
2.55.0
^ permalink raw reply related [flat|nested] 22+ messages in thread* Re: [PATCH v7 7/9] rtc: abx80x: replace read-modify-write pattern with regmap helpers
2026-09-16 20:51 ` [PATCH v7 7/9] rtc: abx80x: replace read-modify-write pattern with regmap helpers Antoni Pokusinski
@ 2026-09-16 21:05 ` sashiko-bot
2026-09-17 18:03 ` Antoni Pokusinski
0 siblings, 1 reply; 22+ messages in thread
From: sashiko-bot @ 2026-09-16 21:05 UTC (permalink / raw)
To: Antoni Pokusinski
Cc: linux-rtc, Alexandre Belloni, devicetree, robh, conor+dt
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] rtc: abx80x: hardware unlock broken by regmap RMW helpers
--
commit aad0cc39d854acf9e4ccd3b1fa7b17484a428c9a
Author: Antoni Pokusinski <apokusinski01@gmail.com>
rtc: abx80x: replace read-modify-write pattern with regmap helpers
This commit refactors the driver to replace open-coded read-modify-write
sequences with the regmap_update_bits() and regmap_write_bits() helpers to
simplify the code.
> diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
> --- a/drivers/rtc/rtc-abx80x.c
> +++ b/drivers/rtc/rtc-abx80x.c
[ ... ]
> @@ -403,13 +388,15 @@ static int abx80x_rtc_set_autocalibration(struct device *dev,
> flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
> }
>
> + guard(mutex)(&priv->lock);
> +
> /* Unlock write access to Oscillator Control Register */
> if (abx80x_write_config_key(dev, ABX8XX_CFG_KEY_OSC) < 0)
> return -EIO;
>
> - retval = regmap_write(priv->regmap, ABX8XX_REG_OSC, flags);
> -
> - return retval;
> + return regmap_write_bits(priv->regmap, ABX8XX_REG_OSC,
> + ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512,
> + flags);
> }
[Severity: High]
Since regmap_write_bits() performs an internal read-modify-write cycle, will
the initial read operation consume the configuration key unlock?
It looks like writing the configuration key only unlocks the very next
transaction. If the regmap helper reads first, the actual write might fail
silently and the hardware would reject the autocalibration settings.
[ ... ]
> @@ -486,24 +472,14 @@ static ssize_t oscillator_store(struct device *dev,
>
> guard(mutex)(&priv->lock);
>
> - retval = regmap_read(priv->regmap, ABX8XX_REG_OSC, &flags);
> - if (retval < 0)
> - return retval;
> -
> - if (rc_mode == 0)
> - flags &= ~(ABX8XX_OSC_OSEL);
> - else
> - flags |= (ABX8XX_OSC_OSEL);
> -
> /* Unlock write access on Oscillator Control register */
> if (abx80x_write_config_key(dev->parent, ABX8XX_CFG_KEY_OSC) < 0)
> return -EIO;
>
> - retval = regmap_write(priv->regmap, ABX8XX_REG_OSC, flags);
> - if (retval < 0) {
> + retval = regmap_write_bits(priv->regmap, ABX8XX_REG_OSC, ABX8XX_OSC_OSEL,
> + rc_mode == 0 ? 0 : (ABX8XX_OSC_OSEL));
> + if (retval < 0)
> dev_err(dev, "Failed to write Oscillator Control register\n");
[Severity: High]
Does the same issue apply here in oscillator_store()? The internal read
within regmap_write_bits() may consume the unlock key, preventing the
oscillator selection from being properly updated.
[ ... ]
> @@ -946,8 +889,14 @@ static int abx80x_probe(struct i2c_client *client)
> if (abx80x_write_config_key(&client->dev, ABX8XX_CFG_KEY_MISC) < 0)
> return -EIO;
>
> - err = regmap_write(regmap, ABX8XX_REG_OUT_CTRL,
> - data | ABX8XX_OUT_CTRL_EXDS);
> + /*
> + * Avoid extra power leakage. The RV1805 uses smaller
> + * 10pin package and the EXTI input is not present.
> + * Disable it to avoid leakage.
> + */
> + err = regmap_write_bits(regmap, ABX8XX_REG_OUT_CTRL,
> + ABX8XX_OUT_CTRL_EXDS,
> + ABX8XX_OUT_CTRL_EXDS);
> if (err < 0) {
[Severity: High]
Could this cause the power leakage mitigation write in abx80x_probe() to be
rejected by the hardware because the unlock transaction was already consumed
by the regmap_write_bits() read phase?
[ ... ]
> @@ -1014,11 +949,10 @@ static int abx80x_probe(struct i2c_client *client)
> if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
> return -EIO;
>
> - err = regmap_write(regmap, ABX8XX_REG_OSC,
> - data & ~(ABX8XX_OSC_ACIE |
> - ABX8XX_OSC_OFIE));
> + err = regmap_write_bits(regmap, ABX8XX_REG_OSC,
> + ABX8XX_OSC_ACIE | ABX8XX_OSC_OFIE, 0);
> if (err < 0) {
[Severity: High]
Will the interrupt disable write also fail silently here due to the unlock
being consumed by the regmap read?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260916205138.16771-1-apokusinski01@gmail.com?part=7
^ permalink raw reply [flat|nested] 22+ messages in thread* Re: [PATCH v7 7/9] rtc: abx80x: replace read-modify-write pattern with regmap helpers
2026-09-16 21:05 ` sashiko-bot
@ 2026-09-17 18:03 ` Antoni Pokusinski
0 siblings, 0 replies; 22+ messages in thread
From: Antoni Pokusinski @ 2026-09-17 18:03 UTC (permalink / raw)
To: sashiko-reviews; +Cc: linux-rtc, Alexandre Belloni, devicetree, robh, conor+dt
On Wed, Sep 16, 2026 at 09:05:20PM +0000, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [High] rtc: abx80x: hardware unlock broken by regmap RMW helpers
> --
>
> commit aad0cc39d854acf9e4ccd3b1fa7b17484a428c9a
> Author: Antoni Pokusinski <apokusinski01@gmail.com>
>
> rtc: abx80x: replace read-modify-write pattern with regmap helpers
>
> This commit refactors the driver to replace open-coded read-modify-write
> sequences with the regmap_update_bits() and regmap_write_bits() helpers to
> simplify the code.
>
> > diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
> > --- a/drivers/rtc/rtc-abx80x.c
> > +++ b/drivers/rtc/rtc-abx80x.c
> [ ... ]
> > @@ -403,13 +388,15 @@ static int abx80x_rtc_set_autocalibration(struct device *dev,
> > flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
> > }
> >
> > + guard(mutex)(&priv->lock);
> > +
> > /* Unlock write access to Oscillator Control Register */
> > if (abx80x_write_config_key(dev, ABX8XX_CFG_KEY_OSC) < 0)
> > return -EIO;
> >
> > - retval = regmap_write(priv->regmap, ABX8XX_REG_OSC, flags);
> > -
> > - return retval;
> > + return regmap_write_bits(priv->regmap, ABX8XX_REG_OSC,
> > + ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512,
> > + flags);
> > }
>
> [Severity: High]
> Since regmap_write_bits() performs an internal read-modify-write cycle, will
> the initial read operation consume the configuration key unlock?
>
Everything alright here, read operations do not cause the configuration
key unlock.
Same thing applies to all the comments below.
> It looks like writing the configuration key only unlocks the very next
> transaction. If the regmap helper reads first, the actual write might fail
> silently and the hardware would reject the autocalibration settings.
>
> [ ... ]
> > @@ -486,24 +472,14 @@ static ssize_t oscillator_store(struct device *dev,
> >
> > guard(mutex)(&priv->lock);
> >
> > - retval = regmap_read(priv->regmap, ABX8XX_REG_OSC, &flags);
> > - if (retval < 0)
> > - return retval;
> > -
> > - if (rc_mode == 0)
> > - flags &= ~(ABX8XX_OSC_OSEL);
> > - else
> > - flags |= (ABX8XX_OSC_OSEL);
> > -
> > /* Unlock write access on Oscillator Control register */
> > if (abx80x_write_config_key(dev->parent, ABX8XX_CFG_KEY_OSC) < 0)
> > return -EIO;
> >
> > - retval = regmap_write(priv->regmap, ABX8XX_REG_OSC, flags);
> > - if (retval < 0) {
> > + retval = regmap_write_bits(priv->regmap, ABX8XX_REG_OSC, ABX8XX_OSC_OSEL,
> > + rc_mode == 0 ? 0 : (ABX8XX_OSC_OSEL));
> > + if (retval < 0)
> > dev_err(dev, "Failed to write Oscillator Control register\n");
>
> [Severity: High]
> Does the same issue apply here in oscillator_store()? The internal read
> within regmap_write_bits() may consume the unlock key, preventing the
> oscillator selection from being properly updated.
>
> [ ... ]
> > @@ -946,8 +889,14 @@ static int abx80x_probe(struct i2c_client *client)
> > if (abx80x_write_config_key(&client->dev, ABX8XX_CFG_KEY_MISC) < 0)
> > return -EIO;
> >
> > - err = regmap_write(regmap, ABX8XX_REG_OUT_CTRL,
> > - data | ABX8XX_OUT_CTRL_EXDS);
> > + /*
> > + * Avoid extra power leakage. The RV1805 uses smaller
> > + * 10pin package and the EXTI input is not present.
> > + * Disable it to avoid leakage.
> > + */
> > + err = regmap_write_bits(regmap, ABX8XX_REG_OUT_CTRL,
> > + ABX8XX_OUT_CTRL_EXDS,
> > + ABX8XX_OUT_CTRL_EXDS);
> > if (err < 0) {
>
> [Severity: High]
> Could this cause the power leakage mitigation write in abx80x_probe() to be
> rejected by the hardware because the unlock transaction was already consumed
> by the regmap_write_bits() read phase?
>
> [ ... ]
> > @@ -1014,11 +949,10 @@ static int abx80x_probe(struct i2c_client *client)
> > if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
> > return -EIO;
> >
> > - err = regmap_write(regmap, ABX8XX_REG_OSC,
> > - data & ~(ABX8XX_OSC_ACIE |
> > - ABX8XX_OSC_OFIE));
> > + err = regmap_write_bits(regmap, ABX8XX_REG_OSC,
> > + ABX8XX_OSC_ACIE | ABX8XX_OSC_OFIE, 0);
> > if (err < 0) {
>
> [Severity: High]
> Will the interrupt disable write also fail silently here due to the unlock
> being consumed by the regmap read?
>
> --
> Sashiko AI review · https://sashiko.dev/#/patchset/20260916205138.16771-1-apokusinski01@gmail.com?part=7
^ permalink raw reply [flat|nested] 22+ messages in thread
* [PATCH v7 8/9] rtc: abx80x: create abx80x_i2c_probe()
2026-09-16 20:51 [PATCH v7 0/9] rtc: abx80x: add support for abx81x Antoni Pokusinski
` (6 preceding siblings ...)
2026-09-16 20:51 ` [PATCH v7 7/9] rtc: abx80x: replace read-modify-write pattern with regmap helpers Antoni Pokusinski
@ 2026-09-16 20:51 ` Antoni Pokusinski
2026-09-16 21:07 ` sashiko-bot
2026-09-16 20:51 ` [PATCH v7 9/9] rtc: abx80x: add support for ABX81X Antoni Pokusinski
2026-10-09 15:06 ` [PATCH v7 0/9] rtc: abx80x: add support for abx81x Alexandre Belloni
9 siblings, 1 reply; 22+ messages in thread
From: Antoni Pokusinski @ 2026-09-16 20:51 UTC (permalink / raw)
To: alexandre.belloni, robh, krzk+dt, conor+dt
Cc: linux-rtc, devicetree, linux-kernel, Antoni Pokusinski
Move the I2C-specific code from abx80x_probe() to the newly created
function. This is a preparation for introducing the support for
ABX81X RTCs which use SPI interface.
Signed-off-by: Antoni Pokusinski <apokusinski01@gmail.com>
---
drivers/rtc/rtc-abx80x.c | 173 ++++++++++++++++++++++++---------------
1 file changed, 106 insertions(+), 67 deletions(-)
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index 53fc788cbf96..3f0f8d7f8761 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -780,73 +780,38 @@ static const struct regmap_access_table abx80x_write_table = {
.n_no_ranges = ARRAY_SIZE(abx80x_no_write_ranges),
};
-static const struct regmap_config abx80x_regmap_config_i2c = {
- .reg_bits = 8,
- .val_bits = 8,
- .max_register = ABX8XX_SRAM_BASE + ABX8XX_SRAM_WIN_SIZE - 1,
-
- .rd_table = &abx80x_read_table,
- .wr_table = &abx80x_write_table,
-};
-
-static const struct i2c_device_id abx80x_id[] = {
- { .name = "abx80x", .driver_data = ABX80X },
- { .name = "ab0801", .driver_data = AB0801 },
- { .name = "ab0803", .driver_data = AB0803 },
- { .name = "ab0804", .driver_data = AB0804 },
- { .name = "ab0805", .driver_data = AB0805 },
- { .name = "ab1801", .driver_data = AB1801 },
- { .name = "ab1803", .driver_data = AB1803 },
- { .name = "ab1804", .driver_data = AB1804 },
- { .name = "ab1805", .driver_data = AB1805 },
- { .name = "rv1805", .driver_data = RV1805 },
- { }
-};
-MODULE_DEVICE_TABLE(i2c, abx80x_id);
-
-static int abx80x_probe(struct i2c_client *client)
+static int abx80x_probe(struct device *dev, struct regmap *regmap, int irq,
+ struct device_node *np, unsigned int part)
{
- struct regmap *regmap;
- struct device_node *np = client->dev.of_node;
struct abx80x_priv *priv;
int i, err, trickle_cfg = -EINVAL;
char buf[7];
- unsigned int part = (uintptr_t)i2c_get_match_data(client);
unsigned int partnumber;
unsigned int majrev, minrev;
unsigned int lot;
unsigned int wafer;
unsigned int uid;
- if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
- return -ENODEV;
-
- regmap = devm_regmap_init_i2c(client, &abx80x_regmap_config_i2c);
- if (IS_ERR(regmap)) {
- dev_err(&client->dev, "Unable to allocate regmap\n");
- return PTR_ERR(regmap);
- }
-
- priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (priv == NULL)
return -ENOMEM;
- priv->rtc = devm_rtc_allocate_device(&client->dev);
+ priv->rtc = devm_rtc_allocate_device(dev);
if (IS_ERR(priv->rtc))
return PTR_ERR(priv->rtc);
priv->rtc->ops = &abx80x_rtc_ops;
- priv->irq = client->irq;
+ priv->irq = irq;
priv->regmap = regmap;
- err = devm_mutex_init(&client->dev, &priv->lock);
+ err = devm_mutex_init(dev, &priv->lock);
if (err)
return err;
- dev_set_drvdata(&client->dev, priv);
+ dev_set_drvdata(dev, priv);
err = regmap_bulk_read(regmap, ABX8XX_REG_ID0, buf, sizeof(buf));
if (err < 0) {
- dev_err(&client->dev, "Unable to read partnumber\n");
+ dev_err(dev, "Unable to read partnumber\n");
return -EIO;
}
@@ -856,14 +821,14 @@ static int abx80x_probe(struct i2c_client *client)
lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
uid = ((buf[4] & 0x7f) << 8) | buf[5];
wafer = (buf[6] & 0x7c) >> 2;
- dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
+ dev_info(dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
partnumber, majrev, minrev, lot, wafer, uid);
err = regmap_update_bits(regmap, ABX8XX_REG_CTRL1,
ABX8XX_CTRL_12_24 | ABX8XX_CTRL_ARST | ABX8XX_CTRL_WRITE,
ABX8XX_CTRL_WRITE);
if (err < 0) {
- dev_err(&client->dev, "Unable to write control register\n");
+ dev_err(dev, "Unable to write control register\n");
return -EIO;
}
@@ -878,7 +843,7 @@ static int abx80x_probe(struct i2c_client *client)
err = regmap_update_bits(regmap, ABX8XX_REG_CTRL2,
ABX8XX_CTRL2_RSVD, 0);
if (err < 0) {
- dev_err(&client->dev, "Unable to write control2 register\n");
+ dev_err(dev, "Unable to write control2 register\n");
return -EIO;
}
@@ -886,7 +851,7 @@ static int abx80x_probe(struct i2c_client *client)
* Write the configuration key register to enable access to
* the config2 register
*/
- if (abx80x_write_config_key(&client->dev, ABX8XX_CFG_KEY_MISC) < 0)
+ if (abx80x_write_config_key(dev, ABX8XX_CFG_KEY_MISC) < 0)
return -EIO;
/*
@@ -898,7 +863,7 @@ static int abx80x_probe(struct i2c_client *client)
ABX8XX_OUT_CTRL_EXDS,
ABX8XX_OUT_CTRL_EXDS);
if (err < 0) {
- dev_err(&client->dev,
+ dev_err(dev,
"Unable to write output control register\n");
return -EIO;
}
@@ -910,26 +875,24 @@ static int abx80x_probe(struct i2c_client *client)
if (partnumber == abx80x_caps[i].pn)
break;
if (abx80x_caps[i].pn == 0) {
- dev_err(&client->dev, "Unknown part: %04x\n",
- partnumber);
+ dev_err(dev, "Unknown part: %04x\n", partnumber);
return -EINVAL;
}
part = i;
}
if (partnumber != abx80x_caps[part].pn) {
- dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
+ dev_err(dev, "partnumber mismatch %04x != %04x\n",
partnumber, abx80x_caps[part].pn);
return -EINVAL;
}
if (np && abx80x_caps[part].has_tc)
- trickle_cfg = abx80x_dt_trickle_cfg(&client->dev);
+ trickle_cfg = abx80x_dt_trickle_cfg(dev);
if (trickle_cfg > 0) {
- dev_info(&client->dev, "Enabling trickle charger: %02x\n",
- trickle_cfg);
- abx80x_enable_trickle_charger(&client->dev, trickle_cfg);
+ dev_info(dev, "Enabling trickle charger: %02x\n", trickle_cfg);
+ abx80x_enable_trickle_charger(dev, trickle_cfg);
}
err = regmap_write(regmap, ABX8XX_REG_CD_TIMER_CTL, BIT(2));
@@ -941,23 +904,23 @@ static int abx80x_probe(struct i2c_client *client)
ABX8XX_IRQ_EX1E | ABX8XX_IRQ_EX2E |
ABX8XX_IRQ_TIE | ABX8XX_IRQ_BLIE, 0);
if (err < 0) {
- dev_err(&client->dev, "Unable to update irq register\n");
+ dev_err(dev, "Unable to update irq register\n");
return -EIO;
}
/* Unlock write access to Oscillator Control Register */
- if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
+ if (abx80x_write_config_key(dev, ABX8XX_CFG_KEY_OSC) < 0)
return -EIO;
err = regmap_write_bits(regmap, ABX8XX_REG_OSC,
ABX8XX_OSC_ACIE | ABX8XX_OSC_OFIE, 0);
if (err < 0) {
- dev_err(&client->dev, "Unable to update Oscillator Control register\n");
+ dev_err(dev, "Unable to update Oscillator Control register\n");
return -EIO;
}
if (abx80x_caps[part].has_wdog) {
- err = abx80x_setup_watchdog(&client->dev);
+ err = abx80x_setup_watchdog(dev);
if (err)
return err;
}
@@ -967,14 +930,14 @@ static int abx80x_probe(struct i2c_client *client)
return err;
if (priv->irq > 0) {
- dev_info(&client->dev, "IRQ %d supplied\n", priv->irq);
- err = devm_request_threaded_irq(&client->dev, priv->irq, NULL,
+ dev_info(dev, "IRQ %d supplied\n", priv->irq);
+ err = devm_request_threaded_irq(dev, priv->irq, NULL,
abx80x_handle_irq,
IRQF_SHARED | IRQF_ONESHOT,
"abx8xx",
- &client->dev);
+ dev);
if (err) {
- dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
+ dev_err(dev, "unable to request IRQ, alarms disabled\n");
priv->irq = 0;
}
}
@@ -983,14 +946,39 @@ static int abx80x_probe(struct i2c_client *client)
err = rtc_add_group(priv->rtc, &rtc_calib_attr_group);
if (err) {
- dev_err(&client->dev, "Failed to create sysfs group: %d\n",
- err);
+ dev_err(dev, "Failed to create sysfs group: %d\n", err);
return err;
}
return devm_rtc_register_device(priv->rtc);
}
+#if IS_ENABLED(CONFIG_I2C)
+
+static const struct regmap_config abx80x_regmap_config_i2c = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = ABX8XX_SRAM_BASE + ABX8XX_SRAM_WIN_SIZE - 1,
+
+ .rd_table = &abx80x_read_table,
+ .wr_table = &abx80x_write_table,
+};
+
+static const struct i2c_device_id abx80x_id[] = {
+ { .name = "abx80x", .driver_data = ABX80X },
+ { .name = "ab0801", .driver_data = AB0801 },
+ { .name = "ab0803", .driver_data = AB0803 },
+ { .name = "ab0804", .driver_data = AB0804 },
+ { .name = "ab0805", .driver_data = AB0805 },
+ { .name = "ab1801", .driver_data = AB1801 },
+ { .name = "ab1803", .driver_data = AB1803 },
+ { .name = "ab1804", .driver_data = AB1804 },
+ { .name = "ab1805", .driver_data = AB1805 },
+ { .name = "rv1805", .driver_data = RV1805 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, abx80x_id);
+
#ifdef CONFIG_OF
static const struct of_device_id abx80x_of_match[] = {
{
@@ -1038,16 +1026,67 @@ static const struct of_device_id abx80x_of_match[] = {
MODULE_DEVICE_TABLE(of, abx80x_of_match);
#endif
+static int abx80x_i2c_probe(struct i2c_client *client)
+{
+ unsigned int part = (uintptr_t)i2c_get_match_data(client);
+ struct regmap *regmap;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+ return -ENODEV;
+
+ regmap = devm_regmap_init_i2c(client, &abx80x_regmap_config_i2c);
+ if (IS_ERR(regmap)) {
+ dev_err(&client->dev, "Unable to allocate regmap\n");
+ return PTR_ERR(regmap);
+ }
+
+ return abx80x_probe(&client->dev, regmap, client->irq,
+ client->dev.of_node, part);
+}
+
static struct i2c_driver abx80x_driver = {
.driver = {
.name = "rtc-abx80x",
.of_match_table = of_match_ptr(abx80x_of_match),
},
- .probe = abx80x_probe,
+ .probe = abx80x_i2c_probe,
.id_table = abx80x_id,
};
-module_i2c_driver(abx80x_driver);
+static int abx80x_register_driver(void)
+{
+ return i2c_add_driver(&abx80x_driver);
+}
+
+static void abx80x_unregister_driver(void)
+{
+ i2c_del_driver(&abx80x_driver);
+}
+
+#else
+
+static int abx80x_register_driver(void)
+{
+ return 0;
+}
+
+static void abx80x_unregister_driver(void)
+{
+}
+
+#endif /* IS_ENABLED(CONFIG_I2C) */
+
+static int __init abx80x_init(void)
+{
+ return abx80x_register_driver();
+}
+module_init(abx80x_init);
+
+static void __exit abx80x_exit(void)
+{
+ abx80x_unregister_driver();
+}
+module_exit(abx80x_exit);
MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
--
2.55.0
^ permalink raw reply related [flat|nested] 22+ messages in thread* [PATCH v7 9/9] rtc: abx80x: add support for ABX81X
2026-09-16 20:51 [PATCH v7 0/9] rtc: abx80x: add support for abx81x Antoni Pokusinski
` (7 preceding siblings ...)
2026-09-16 20:51 ` [PATCH v7 8/9] rtc: abx80x: create abx80x_i2c_probe() Antoni Pokusinski
@ 2026-09-16 20:51 ` Antoni Pokusinski
2026-09-16 21:06 ` sashiko-bot
2026-10-09 15:06 ` [PATCH v7 0/9] rtc: abx80x: add support for abx81x Alexandre Belloni
9 siblings, 1 reply; 22+ messages in thread
From: Antoni Pokusinski @ 2026-09-16 20:51 UTC (permalink / raw)
To: alexandre.belloni, robh, krzk+dt, conor+dt
Cc: linux-rtc, devicetree, linux-kernel, Antoni Pokusinski
Abracon ABX81X is a family of RTCs with SPI interface featuring
the same functionalities as the ABX80X I2C clocks.
Signed-off-by: Antoni Pokusinski <apokusinski01@gmail.com>
---
drivers/rtc/Kconfig | 26 +++++-----
drivers/rtc/rtc-abx80x.c | 106 +++++++++++++++++++++++++++++++++++++--
2 files changed, 115 insertions(+), 17 deletions(-)
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 4d14bcba616e..d35221f81024 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -212,18 +212,6 @@ config RTC_DRV_ABEOZ9
This driver can also be built as a module. If so, the module
will be called rtc-ab-e0z9.
-config RTC_DRV_ABX80X
- tristate "Abracon ABx80x"
- select WATCHDOG_CORE if WATCHDOG
- select REGMAP_I2C
- help
- If you say yes here you get support for Abracon AB080X and AB180X
- families of ultra-low-power battery- and capacitor-backed real-time
- clock chips.
-
- This driver can also be built as a module. If so, the module
- will be called rtc-abx80x.
-
config RTC_DRV_AC100
tristate "X-Powers AC100"
depends on MFD_AC100
@@ -955,6 +943,20 @@ config RTC_I2C_AND_SPI
comment "SPI and I2C RTC drivers"
+config RTC_DRV_ABX80X
+ tristate "Abracon ABx80x"
+ depends on RTC_I2C_AND_SPI
+ select WATCHDOG_CORE if WATCHDOG
+ select REGMAP_I2C if I2C
+ select REGMAP_SPI if SPI_MASTER
+ help
+ If you say yes here you get support for Abracon AB080X, AB180X,
+ AB081X and AB181X families of ultra-low-power battery- and
+ capacitor-backed real-time clock chips.
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-abx80x.
+
config RTC_DRV_DS3232
tristate "Dallas/Maxim DS3232/DS3234"
depends on RTC_I2C_AND_SPI
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index 3f0f8d7f8761..718e6b8555f5 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -1,7 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * A driver for the I2C members of the Abracon AB x8xx RTC family,
- * and compatible: AB 1805 and AB 0805
+ * A driver for the I2C and SPI members of the Abracon AB x8xx RTC family,
+ * and compatible: AB 1805, AB 0805, AB 1815 and AB 0815
*
* Copyright 2014-2015 Macq S.A.
*
@@ -19,6 +19,7 @@
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
+#include <linux/spi/spi.h>
#include <linux/watchdog.h>
#define ABX8XX_REG_HTH 0x00
@@ -109,8 +110,8 @@
static u8 trickle_resistors[] = {0, 3, 6, 11};
-enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
- AB1801, AB1803, AB1804, AB1805, RV1805, ABX80X};
+enum abx80x_chip {AB0801, AB0803, AB0804, AB0805, AB0815,
+ AB1801, AB1803, AB1804, AB1805, AB1815, RV1805, ABX80X};
struct abx80x_cap {
u16 pn;
@@ -123,10 +124,12 @@ static struct abx80x_cap abx80x_caps[] = {
[AB0803] = {.pn = 0x0803},
[AB0804] = {.pn = 0x0804, .has_tc = true, .has_wdog = true},
[AB0805] = {.pn = 0x0805, .has_tc = true, .has_wdog = true},
+ [AB0815] = {.pn = 0x0815, .has_tc = true, .has_wdog = true},
[AB1801] = {.pn = 0x1801},
[AB1803] = {.pn = 0x1803},
[AB1804] = {.pn = 0x1804, .has_tc = true, .has_wdog = true},
[AB1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
+ [AB1815] = {.pn = 0x1815, .has_tc = true, .has_wdog = true},
[RV1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
[ABX80X] = {.pn = 0}
};
@@ -1076,14 +1079,107 @@ static void abx80x_unregister_driver(void)
#endif /* IS_ENABLED(CONFIG_I2C) */
+#if IS_ENABLED(CONFIG_SPI_MASTER)
+
+static const struct regmap_config abx80x_regmap_config_spi = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = ABX8XX_SRAM_BASE + ABX8XX_SRAM_WIN_SIZE - 1,
+
+ .rd_table = &abx80x_read_table,
+ .wr_table = &abx80x_write_table,
+
+ .write_flag_mask = BIT(7),
+};
+
+static const struct spi_device_id abx81x_id[] = {
+ { "ab0815", AB0815 },
+ { "ab1815", AB1815 },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, abx81x_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id abx81x_of_match[] = {
+ {
+ .compatible = "abracon,ab0815",
+ .data = (void *)AB0815
+ },
+ {
+ .compatible = "abracon,ab1815",
+ .data = (void *)AB1815
+ },
+ { }
+};
+MODULE_DEVICE_TABLE(of, abx81x_of_match);
+#endif
+
+static int abx81x_spi_probe(struct spi_device *spi)
+{
+ unsigned int part = (uintptr_t)spi_get_device_match_data(spi);
+ struct regmap *regmap;
+
+ regmap = devm_regmap_init_spi(spi, &abx80x_regmap_config_spi);
+ if (IS_ERR(regmap)) {
+ dev_err(&spi->dev, "Unable to allocate regmap\n");
+ return PTR_ERR(regmap);
+ }
+
+ return abx80x_probe(&spi->dev, regmap, spi->irq,
+ spi->dev.of_node, part);
+}
+
+static struct spi_driver abx81x_driver = {
+ .driver = {
+ .name = "rtc-abx81x",
+ .of_match_table = of_match_ptr(abx81x_of_match),
+ },
+ .probe = abx81x_spi_probe,
+ .id_table = abx81x_id,
+};
+
+static int abx81x_register_driver(void)
+{
+ return spi_register_driver(&abx81x_driver);
+}
+
+static void abx81x_unregister_driver(void)
+{
+ spi_unregister_driver(&abx81x_driver);
+}
+
+#else
+
+static int abx81x_register_driver(void)
+{
+ return 0;
+}
+
+static void abx81x_unregister_driver(void)
+{
+}
+
+#endif /* IS_ENABLED(CONFIG_SPI_MASTER) */
+
static int __init abx80x_init(void)
{
- return abx80x_register_driver();
+ int ret;
+
+ ret = abx80x_register_driver();
+ if (ret)
+ return ret;
+
+ ret = abx81x_register_driver();
+ if (ret)
+ abx80x_unregister_driver();
+
+ return ret;
}
module_init(abx80x_init);
static void __exit abx80x_exit(void)
{
+ abx81x_unregister_driver();
abx80x_unregister_driver();
}
module_exit(abx80x_exit);
--
2.55.0
^ permalink raw reply related [flat|nested] 22+ messages in thread* Re: [PATCH v7 0/9] rtc: abx80x: add support for abx81x
2026-09-16 20:51 [PATCH v7 0/9] rtc: abx80x: add support for abx81x Antoni Pokusinski
` (8 preceding siblings ...)
2026-09-16 20:51 ` [PATCH v7 9/9] rtc: abx80x: add support for ABX81X Antoni Pokusinski
@ 2026-10-09 15:06 ` Alexandre Belloni
9 siblings, 0 replies; 22+ messages in thread
From: Alexandre Belloni @ 2026-10-09 15:06 UTC (permalink / raw)
To: robh, krzk+dt, conor+dt, Antoni Pokusinski
Cc: linux-rtc, devicetree, linux-kernel
On Wed, 16 Sep 2026 22:51:29 +0200, Antoni Pokusinski wrote:
> This patch series adds support for the ABX81X RTCs, which are essentially
> SPI versions of the ABX80X RTCs. The first patches (P2-P4) contain bug fixes
> (added after sashiko's review in v1-v5), then (P5-P8) we have some cleanup and
> reorganization changes (converting the driver to use the regmap API was
> needed for this), followed by the actual ABX81X support.
>
> Kind regards,
> Antoni Pokusinski
>
> [...]
Applied, thanks!
[1/9] dt-bindings: rtc: abx80x: document ABX81X RTCs
https://git.kernel.org/abelloni/c/953c3d2b5836
[2/9] rtc: abx80x: fix error check after i2c_smbus_read in read_alarm()
https://git.kernel.org/abelloni/c/07c57022afb3
[3/9] rtc: abx80x: add mutex protection for register writes
https://git.kernel.org/abelloni/c/74bff654a4ce
[4/9] rtc: abx80x: properly handle shared IRQs
https://git.kernel.org/abelloni/c/632916c7bde3
[5/9] rtc: abx80x: add irq to struct abx80x_priv
https://git.kernel.org/abelloni/c/00b978f8008e
[6/9] rtc: abx80x: use regmap instead of I2C specific API
https://git.kernel.org/abelloni/c/724320a61325
[7/9] rtc: abx80x: replace read-modify-write pattern with regmap helpers
https://git.kernel.org/abelloni/c/0ba70c2b1e3e
[8/9] rtc: abx80x: create abx80x_i2c_probe()
https://git.kernel.org/abelloni/c/3fcf5a97957b
[9/9] rtc: abx80x: add support for ABX81X
https://git.kernel.org/abelloni/c/8a017ab98412
Best regards,
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
^ permalink raw reply [flat|nested] 22+ messages in thread