* [PATCH 1/4] dt-bindings: rtc: abracon,abx80x: Add sqw property
2021-03-28 21:02 [PATCH 0/4] rtc:abx80x: Enable distributed digital calibration Kirill Kapranov
@ 2021-03-28 21:02 ` Kirill Kapranov
2021-03-28 21:02 ` [PATCH 2/4] rtc: abx80x: Enable SQW output Kirill Kapranov
` (3 subsequent siblings)
4 siblings, 0 replies; 11+ messages in thread
From: Kirill Kapranov @ 2021-03-28 21:02 UTC (permalink / raw)
To: a.zummo, alexandre.belloni, phdm, linux-rtc, linux-kernel; +Cc: Kirill Kapranov
Introduce the string property "sqw" to control Square Wave Output register.
This enables pulse generation output, that is useful for xtal calibration
or for an external usage.
Signed-off-by: Kirill Kapranov <kirill.kapranov@compulab.co.il>
---
Documentation/devicetree/bindings/rtc/abracon,abx80x.txt | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/Documentation/devicetree/bindings/rtc/abracon,abx80x.txt b/Documentation/devicetree/bindings/rtc/abracon,abx80x.txt
index 2405e35a1bc0..4c545ece33b5 100644
--- a/Documentation/devicetree/bindings/rtc/abracon,abx80x.txt
+++ b/Documentation/devicetree/bindings/rtc/abracon,abx80x.txt
@@ -29,3 +29,15 @@ and valid to enable charging:
- "abracon,tc-diode": should be "standard" (0.6V) or "schottky" (0.3V)
- "abracon,tc-resistor": should be <0>, <3>, <6> or <11>. 0 disables the output
resistor, the other values are in kOhm.
+
+The RTC can produce square wave output on a dedicated pin for an external usage
+or for calibration purpose. A valid string should be assigned to the "sqw"
+property to enable the output:
+
+ - "sqw": should be one of the following:
+ "1_century", "32768_Hz", "8192_Hz", "4096_Hz", "2048_Hz", "1024_Hz",
+ "512_Hz", "256_Hz", "128_Hz", "64_Hz", "32_Hz", "16_Hz", "8_Hz", "4_Hz",
+ "2_Hz", "1_Hz", "1/2_Hz", "1/4_Hz", "1/8_Hz", "1/16_Hz", "1/32_Hz",
+ "1_min", "16384_Hz", "100_Hz", "1_hour", "1_day", "TIRQ", "nTIRQ",
+ "1_year", "1_Hz_to_Counters", "1/32_Hz_from_Acal", "1/8_Hz_from_Acal",
+ "none"
--
2.11.0
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 2/4] rtc: abx80x: Enable SQW output
2021-03-28 21:02 [PATCH 0/4] rtc:abx80x: Enable distributed digital calibration Kirill Kapranov
2021-03-28 21:02 ` [PATCH 1/4] dt-bindings: rtc: abracon,abx80x: Add sqw property Kirill Kapranov
@ 2021-03-28 21:02 ` Kirill Kapranov
2021-03-29 0:34 ` kernel test robot
2021-03-29 6:19 ` Dan Carpenter
2021-03-28 21:02 ` [PATCH 3/4] dt-bindings: rtc: abracon,abx80x: Add xt-frequency property Kirill Kapranov
` (2 subsequent siblings)
4 siblings, 2 replies; 11+ messages in thread
From: Kirill Kapranov @ 2021-03-28 21:02 UTC (permalink / raw)
To: a.zummo, alexandre.belloni, phdm, linux-rtc, linux-kernel; +Cc: Kirill Kapranov
The RTCs of the family are able to produce square wave output for RTC
calibration purposes or for an external usage.
Signed-off-by: Kirill Kapranov <kirill.kapranov@compulab.co.il>
---
drivers/rtc/rtc-abx80x.c | 126 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 126 insertions(+)
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index 9b0138d07232..153d89b56da9 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -51,6 +51,9 @@
#define ABX8XX_IRQ_AIE BIT(2)
#define ABX8XX_IRQ_IM_1_4 (0x3 << 5)
+#define ABX8XX_REG_SQW 0x13
+#define ABX8XX_SQW_MODE_BITS 5
+
#define ABX8XX_REG_CD_TIMER_CTL 0x18
#define ABX8XX_REG_OSC 0x1c
@@ -117,6 +120,15 @@ struct abx80x_priv {
struct watchdog_device wdog;
};
+union abx8xx_reg_sqw {
+ struct {
+ unsigned int sqws:5;
+ int:2;
+ unsigned int sqwe:2;
+ };
+ int val;
+} __packed;
+
static int abx80x_write_config_key(struct i2c_client *client, u8 key)
{
if (i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY, key) < 0) {
@@ -486,9 +498,119 @@ static ssize_t oscillator_show(struct device *dev,
static DEVICE_ATTR_RW(oscillator);
+#define SQFS_COUNT (1 << ABX8XX_SQW_MODE_BITS)
+/* The index of the array is the value to be written to the 'Square Wave Function
+ * Select' register to make the RTC generate the required square wave.
+ */
+static const char *const sqfs[SQFS_COUNT] = {
+ "1_century", "32768_Hz", "8192_Hz", "4096_Hz",
+ "2048_Hz", "1024_Hz", "512_Hz", "256_Hz",
+ "128_Hz", "64_Hz", "32_Hz", "16_Hz",
+ "8_Hz", "4_Hz", "2_Hz", "1_Hz",
+ "1/2_Hz", "1/4_Hz", "1/8_Hz", "1/16_Hz",
+ "1/32_Hz", "1_min", "16384_Hz", "100_Hz",
+ "1_hour", "1_day", "TIRQ", "nTIRQ",
+ "1_year", "1_Hz_to_Counters", "1/32_Hz_from_Acal", "1/8_Hz_from_Acal",
+};
+
+static const bool valid_for_rc_mode[SQFS_COUNT] = {
+ true, false, false, false,
+ false, false, false, false,
+ true, true, true, true,
+ true, true, true, true,
+ true, true, true, true,
+ true, true, false, false,
+ true, true, true, true,
+ true, true, true, true,
+};
+
+static int sqw_set(struct i2c_client *client, const char *buf)
+{
+ union abx8xx_reg_sqw reg_sqw;
+ int retval;
+
+ reg_sqw.val = i2c_smbus_read_byte_data(client, ABX8XX_REG_SQW);
+ if (reg_sqw.val < 0)
+ goto err;
+
+ if (sysfs_streq(buf, "none")) {
+ reg_sqw.sqwe = 0;
+ dev_info(&client->dev, "sqw output disabled\n");
+ } else {
+ int idx = __sysfs_match_string(sqfs, SQFS_COUNT, buf);
+
+ if (idx < 0)
+ return idx;
+
+ if (abx80x_is_rc_mode(client) && !valid_for_rc_mode[idx])
+ dev_warn(&client->dev, "sqw frequency %s valid only in xt mode\n",
+ sqfs[idx]);
+
+ dev_info(&client->dev, "sqw output enabled @ %s\n", sqfs[idx]);
+ reg_sqw.sqwe = 1;
+ reg_sqw.sqws = idx;
+ }
+
+ retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_SQW, reg_sqw.val);
+ if (retval < 0)
+ goto err;
+
+ return 0;
+err:
+ dev_err(&client->dev, "Failed to set SQW\n");
+ return retval;
+
+}
+
+static ssize_t sqw_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int retval;
+
+ retval = sqw_set(to_i2c_client(dev->parent), buf);
+ if (retval)
+ return retval;
+ else
+ return count;
+}
+
+static ssize_t sqw_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct i2c_client *client = to_i2c_client(dev->parent);
+ union abx8xx_reg_sqw reg_sqw;
+ int len = 0;
+ int i;
+
+ reg_sqw.val = i2c_smbus_read_byte_data(client, ABX8XX_REG_SQW);
+ if (reg_sqw.val < 0) {
+ dev_err(dev, "Failed to read SQW\n");
+ sprintf(buf, "\n");
+ return reg_sqw.val;
+ }
+
+ if (reg_sqw.sqwe)
+ len += scnprintf(buf+len, PAGE_SIZE - len, "none ");
+ else
+ len += scnprintf(buf+len, PAGE_SIZE - len, "[none] ");
+
+ for (i = 0; i < SQFS_COUNT; ++i) {
+ if (reg_sqw.sqwe && i == reg_sqw.sqws)
+ len += scnprintf(buf+len, PAGE_SIZE - len, "[%s] ", sqfs[i]);
+ else
+ len += scnprintf(buf+len, PAGE_SIZE - len, "%s ", sqfs[i]);
+ }
+
+ return len;
+}
+
+static DEVICE_ATTR_RW(sqw);
+
static struct attribute *rtc_calib_attrs[] = {
&dev_attr_autocalibration.attr,
&dev_attr_oscillator.attr,
+ &dev_attr_sqw.attr,
NULL,
};
@@ -686,6 +808,7 @@ static int abx80x_probe(struct i2c_client *client,
unsigned int lot;
unsigned int wafer;
unsigned int uid;
+ const char *sqw_mode_name;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
@@ -800,6 +923,9 @@ static int abx80x_probe(struct i2c_client *client,
abx80x_enable_trickle_charger(client, trickle_cfg);
}
+ if (!of_property_read_string(np, "sqw", &sqw_mode_name))
+ sqw_set(client, sqw_mode_name);
+
err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
BIT(2));
if (err)
--
2.11.0
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH 2/4] rtc: abx80x: Enable SQW output
2021-03-28 21:02 ` [PATCH 2/4] rtc: abx80x: Enable SQW output Kirill Kapranov
@ 2021-03-29 0:34 ` kernel test robot
2021-03-29 6:19 ` Dan Carpenter
1 sibling, 0 replies; 11+ messages in thread
From: kernel test robot @ 2021-03-29 0:34 UTC (permalink / raw)
To: Kirill Kapranov, a.zummo, alexandre.belloni, phdm, linux-rtc,
linux-kernel
Cc: kbuild-all, clang-built-linux, Kirill Kapranov
[-- Attachment #1: Type: text/plain, Size: 3600 bytes --]
Hi Kirill,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on abelloni/rtc-next]
[also build test WARNING on v5.12-rc5 next-20210326]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Kirill-Kapranov/rtc-abx80x-Enable-distributed-digital-calibration/20210329-053233
base: https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux.git rtc-next
config: arm-randconfig-r034-20210329 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 821547cabb5819ed42245376a9afcd11cdee5ddd)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm cross compiling tool for clang build
# apt-get install binutils-arm-linux-gnueabi
# https://github.com/0day-ci/linux/commit/3f6d456de4f347f0d2fd0af648b1ca21b1212d17
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Kirill-Kapranov/rtc-abx80x-Enable-distributed-digital-calibration/20210329-053233
git checkout 3f6d456de4f347f0d2fd0af648b1ca21b1212d17
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> drivers/rtc/rtc-abx80x.c:533:6: warning: variable 'retval' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
if (reg_sqw.val < 0)
^~~~~~~~~~~~~~~
drivers/rtc/rtc-abx80x.c:561:9: note: uninitialized use occurs here
return retval;
^~~~~~
drivers/rtc/rtc-abx80x.c:533:2: note: remove the 'if' if its condition is always false
if (reg_sqw.val < 0)
^~~~~~~~~~~~~~~~~~~~
drivers/rtc/rtc-abx80x.c:530:12: note: initialize the variable 'retval' to silence this warning
int retval;
^
= 0
1 warning generated.
vim +533 drivers/rtc/rtc-abx80x.c
526
527 static int sqw_set(struct i2c_client *client, const char *buf)
528 {
529 union abx8xx_reg_sqw reg_sqw;
530 int retval;
531
532 reg_sqw.val = i2c_smbus_read_byte_data(client, ABX8XX_REG_SQW);
> 533 if (reg_sqw.val < 0)
534 goto err;
535
536 if (sysfs_streq(buf, "none")) {
537 reg_sqw.sqwe = 0;
538 dev_info(&client->dev, "sqw output disabled\n");
539 } else {
540 int idx = __sysfs_match_string(sqfs, SQFS_COUNT, buf);
541
542 if (idx < 0)
543 return idx;
544
545 if (abx80x_is_rc_mode(client) && !valid_for_rc_mode[idx])
546 dev_warn(&client->dev, "sqw frequency %s valid only in xt mode\n",
547 sqfs[idx]);
548
549 dev_info(&client->dev, "sqw output enabled @ %s\n", sqfs[idx]);
550 reg_sqw.sqwe = 1;
551 reg_sqw.sqws = idx;
552 }
553
554 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_SQW, reg_sqw.val);
555 if (retval < 0)
556 goto err;
557
558 return 0;
559 err:
560 dev_err(&client->dev, "Failed to set SQW\n");
561 return retval;
562
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 32508 bytes --]
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 2/4] rtc: abx80x: Enable SQW output
2021-03-28 21:02 ` [PATCH 2/4] rtc: abx80x: Enable SQW output Kirill Kapranov
2021-03-29 0:34 ` kernel test robot
@ 2021-03-29 6:19 ` Dan Carpenter
2021-03-30 15:28 ` Kirill Kapranov
1 sibling, 1 reply; 11+ messages in thread
From: Dan Carpenter @ 2021-03-29 6:19 UTC (permalink / raw)
To: kbuild, Kirill Kapranov, a.zummo, alexandre.belloni, phdm,
linux-rtc, linux-kernel
Cc: lkp, kbuild-all, Kirill Kapranov
[-- Attachment #1: Type: text/plain, Size: 3682 bytes --]
Hi Kirill,
url: https://github.com/0day-ci/linux/commits/Kirill-Kapranov/rtc-abx80x-Enable-distributed-digital-calibration/20210329-053233
base: https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux.git rtc-next
config: i386-randconfig-m021-20210328 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
smatch warnings:
drivers/rtc/rtc-abx80x.c:561 sqw_set() error: uninitialized symbol 'retval'.
vim +/retval +561 drivers/rtc/rtc-abx80x.c
3f6d456de4f347 Kirill Kapranov 2021-03-29 527 static int sqw_set(struct i2c_client *client, const char *buf)
3f6d456de4f347 Kirill Kapranov 2021-03-29 528 {
3f6d456de4f347 Kirill Kapranov 2021-03-29 529 union abx8xx_reg_sqw reg_sqw;
3f6d456de4f347 Kirill Kapranov 2021-03-29 530 int retval;
3f6d456de4f347 Kirill Kapranov 2021-03-29 531
3f6d456de4f347 Kirill Kapranov 2021-03-29 532 reg_sqw.val = i2c_smbus_read_byte_data(client, ABX8XX_REG_SQW);
3f6d456de4f347 Kirill Kapranov 2021-03-29 533 if (reg_sqw.val < 0)
3f6d456de4f347 Kirill Kapranov 2021-03-29 534 goto err;
"retval" not set. Forgetting to set the error code is the canonical
bug for do nothing gotos like this.
3f6d456de4f347 Kirill Kapranov 2021-03-29 535
3f6d456de4f347 Kirill Kapranov 2021-03-29 536 if (sysfs_streq(buf, "none")) {
3f6d456de4f347 Kirill Kapranov 2021-03-29 537 reg_sqw.sqwe = 0;
3f6d456de4f347 Kirill Kapranov 2021-03-29 538 dev_info(&client->dev, "sqw output disabled\n");
3f6d456de4f347 Kirill Kapranov 2021-03-29 539 } else {
3f6d456de4f347 Kirill Kapranov 2021-03-29 540 int idx = __sysfs_match_string(sqfs, SQFS_COUNT, buf);
3f6d456de4f347 Kirill Kapranov 2021-03-29 541
3f6d456de4f347 Kirill Kapranov 2021-03-29 542 if (idx < 0)
3f6d456de4f347 Kirill Kapranov 2021-03-29 543 return idx;
^^^^^^^^^^^
These are direct returns. Just do direct returns everywhere (more
readably, fewer bugs).
3f6d456de4f347 Kirill Kapranov 2021-03-29 544
3f6d456de4f347 Kirill Kapranov 2021-03-29 545 if (abx80x_is_rc_mode(client) && !valid_for_rc_mode[idx])
3f6d456de4f347 Kirill Kapranov 2021-03-29 546 dev_warn(&client->dev, "sqw frequency %s valid only in xt mode\n",
3f6d456de4f347 Kirill Kapranov 2021-03-29 547 sqfs[idx]);
3f6d456de4f347 Kirill Kapranov 2021-03-29 548
3f6d456de4f347 Kirill Kapranov 2021-03-29 549 dev_info(&client->dev, "sqw output enabled @ %s\n", sqfs[idx]);
3f6d456de4f347 Kirill Kapranov 2021-03-29 550 reg_sqw.sqwe = 1;
3f6d456de4f347 Kirill Kapranov 2021-03-29 551 reg_sqw.sqws = idx;
3f6d456de4f347 Kirill Kapranov 2021-03-29 552 }
3f6d456de4f347 Kirill Kapranov 2021-03-29 553
3f6d456de4f347 Kirill Kapranov 2021-03-29 554 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_SQW, reg_sqw.val);
3f6d456de4f347 Kirill Kapranov 2021-03-29 555 if (retval < 0)
3f6d456de4f347 Kirill Kapranov 2021-03-29 556 goto err;
3f6d456de4f347 Kirill Kapranov 2021-03-29 557
3f6d456de4f347 Kirill Kapranov 2021-03-29 558 return 0;
3f6d456de4f347 Kirill Kapranov 2021-03-29 559 err:
3f6d456de4f347 Kirill Kapranov 2021-03-29 560 dev_err(&client->dev, "Failed to set SQW\n");
3f6d456de4f347 Kirill Kapranov 2021-03-29 @561 return retval;
^^^^^^^^^^^^^
3f6d456de4f347 Kirill Kapranov 2021-03-29 562
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 35066 bytes --]
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 2/4] rtc: abx80x: Enable SQW output
2021-03-29 6:19 ` Dan Carpenter
@ 2021-03-30 15:28 ` Kirill Kapranov
0 siblings, 0 replies; 11+ messages in thread
From: Kirill Kapranov @ 2021-03-30 15:28 UTC (permalink / raw)
To: Dan Carpenter, kbuild, a.zummo, alexandre.belloni, phdm,
linux-rtc, linux-kernel
Cc: lkp, kbuild-all
Hi Dan,
Thank you very much for pointing out the issues.
However, I'm not sure that the code, you have analyzed, will be a part
of final patch set. I intend to redesign all the code deeply, as
Alexandre Belloni suggested [1].
Thank you again!
--
Best Regards,
Kirill Kapranov
Software Engineer
CompuLab Ltd.
[1] https://marc.info/?l=linux-rtc&m=161696606727215&w=2
On 3/29/21 9:19 AM, Dan Carpenter wrote:
> Hi Kirill,
>
> url: https://github.com/0day-ci/linux/commits/Kirill-Kapranov/rtc-abx80x-Enable-distributed-digital-calibration/20210329-053233
> base: https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux.git rtc-next
> config: i386-randconfig-m021-20210328 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> smatch warnings:
> drivers/rtc/rtc-abx80x.c:561 sqw_set() error: uninitialized symbol 'retval'.
>
> vim +/retval +561 drivers/rtc/rtc-abx80x.c
>
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 527 static int sqw_set(struct i2c_client *client, const char *buf)
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 528 {
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 529 union abx8xx_reg_sqw reg_sqw;
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 530 int retval;
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 531
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 532 reg_sqw.val = i2c_smbus_read_byte_data(client, ABX8XX_REG_SQW);
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 533 if (reg_sqw.val < 0)
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 534 goto err;
>
> "retval" not set. Forgetting to set the error code is the canonical
> bug for do nothing gotos like this.
>
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 535
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 536 if (sysfs_streq(buf, "none")) {
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 537 reg_sqw.sqwe = 0;
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 538 dev_info(&client->dev, "sqw output disabled\n");
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 539 } else {
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 540 int idx = __sysfs_match_string(sqfs, SQFS_COUNT, buf);
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 541
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 542 if (idx < 0)
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 543 return idx;
> ^^^^^^^^^^^
> These are direct returns. Just do direct returns everywhere (more
> readably, fewer bugs).
>
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 544
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 545 if (abx80x_is_rc_mode(client) && !valid_for_rc_mode[idx])
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 546 dev_warn(&client->dev, "sqw frequency %s valid only in xt mode\n",
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 547 sqfs[idx]);
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 548
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 549 dev_info(&client->dev, "sqw output enabled @ %s\n", sqfs[idx]);
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 550 reg_sqw.sqwe = 1;
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 551 reg_sqw.sqws = idx;
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 552 }
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 553
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 554 retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_SQW, reg_sqw.val);
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 555 if (retval < 0)
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 556 goto err;
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 557
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 558 return 0;
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 559 err:
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 560 dev_err(&client->dev, "Failed to set SQW\n");
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 @561 return retval;
> ^^^^^^^^^^^^^
>
> 3f6d456de4f347 Kirill Kapranov 2021-03-29 562
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 3/4] dt-bindings: rtc: abracon,abx80x: Add xt-frequency property
2021-03-28 21:02 [PATCH 0/4] rtc:abx80x: Enable distributed digital calibration Kirill Kapranov
2021-03-28 21:02 ` [PATCH 1/4] dt-bindings: rtc: abracon,abx80x: Add sqw property Kirill Kapranov
2021-03-28 21:02 ` [PATCH 2/4] rtc: abx80x: Enable SQW output Kirill Kapranov
@ 2021-03-28 21:02 ` Kirill Kapranov
2021-03-28 21:02 ` [PATCH 4/4] rtc:abx80x: Enable xt digital calibration Kirill Kapranov
2021-03-28 21:14 ` [PATCH 0/4] rtc:abx80x: Enable distributed " Alexandre Belloni
4 siblings, 0 replies; 11+ messages in thread
From: Kirill Kapranov @ 2021-03-28 21:02 UTC (permalink / raw)
To: a.zummo, alexandre.belloni, phdm, linux-rtc, linux-kernel; +Cc: Kirill Kapranov
Add the string property "xt-frequency" to control xtal calibration of the
RTC. This allows to improve the RTC accuracy using a Distributed Digital
Calibration function. See: ch. 5.9.1 of
AB08XX Series Ultra Low Power RTC IC User's Guide
https://abracon.com/realtimeclock/AB08XX-Application-Manual.pdf
Signed-off-by: Kirill Kapranov <kirill.kapranov@compulab.co.il>
---
Documentation/devicetree/bindings/rtc/abracon,abx80x.txt | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/Documentation/devicetree/bindings/rtc/abracon,abx80x.txt b/Documentation/devicetree/bindings/rtc/abracon,abx80x.txt
index 4c545ece33b5..fac36db7460e 100644
--- a/Documentation/devicetree/bindings/rtc/abracon,abx80x.txt
+++ b/Documentation/devicetree/bindings/rtc/abracon,abx80x.txt
@@ -41,3 +41,16 @@ property to enable the output:
"1_min", "16384_Hz", "100_Hz", "1_hour", "1_day", "TIRQ", "nTIRQ",
"1_year", "1_Hz_to_Counters", "1/32_Hz_from_Acal", "1/8_Hz_from_Acal",
"none"
+
+The RTCs support XT calibration that allows to improve the RTC accuracy.
+To perform the calibration follow the instruction:
+
+ Write the nominal XT frequency (in milliHerz) 32768000 to
+ /sys/class/rtc/your_rtc/xt-frequency
+ to ensure the calibration is not occurring.
+ Select the XT oscillator by writing by writing xtal to
+ /sys/class/rtc/your_rtc/oscillator
+ Configure the square wave SQW output by writing
+ 32768_Hz to /sys/class/rtc/your_rtc/sqw
+ Measure the square wave frequency on the output pin in milliHerz.
+ Assign the measured value to the property xt-frequency.
--
2.11.0
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 4/4] rtc:abx80x: Enable xt digital calibration
2021-03-28 21:02 [PATCH 0/4] rtc:abx80x: Enable distributed digital calibration Kirill Kapranov
` (2 preceding siblings ...)
2021-03-28 21:02 ` [PATCH 3/4] dt-bindings: rtc: abracon,abx80x: Add xt-frequency property Kirill Kapranov
@ 2021-03-28 21:02 ` Kirill Kapranov
2021-04-09 10:46 ` Pavel Machek
2021-03-28 21:14 ` [PATCH 0/4] rtc:abx80x: Enable distributed " Alexandre Belloni
4 siblings, 1 reply; 11+ messages in thread
From: Kirill Kapranov @ 2021-03-28 21:02 UTC (permalink / raw)
To: a.zummo, alexandre.belloni, phdm, linux-rtc, linux-kernel; +Cc: Kirill Kapranov
The XT digital calibration feature allows to improve the RTC accuracy,
using a Distributed Digital Calibration function.
See ch. 5.9.1 of AB08XX Series Ultra Low Power RTC IC User's Guide
https://abracon.com/realtimeclock/AB08XX-Application-Manual.pdf
Signed-off-by: Kirill Kapranov <kirill.kapranov@compulab.co.il>
---
drivers/rtc/rtc-abx80x.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 145 insertions(+)
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index 153d89b56da9..e13fa88e87a5 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -54,6 +54,9 @@
#define ABX8XX_REG_SQW 0x13
#define ABX8XX_SQW_MODE_BITS 5
+#define ABX8XX_REG_CAL_XT 0x14
+#define ABX8XX_CAL_XT_OFFSETX_MASK GENMASK(6, 0)
+
#define ABX8XX_REG_CD_TIMER_CTL 0x18
#define ABX8XX_REG_OSC 0x1c
@@ -120,6 +123,22 @@ struct abx80x_priv {
struct watchdog_device wdog;
};
+union abx8xx_reg_cal_xt {
+ struct {
+ int offsetx:7;
+ unsigned int cmdx:1;
+ };
+ int val;
+} __packed;
+
+union abx8xx_reg_oss {
+ struct {
+ int:6;
+ unsigned int xtcal:2;
+ };
+ int val;
+} __packed;
+
union abx8xx_reg_sqw {
struct {
unsigned int sqws:5;
@@ -498,6 +517,123 @@ static ssize_t oscillator_show(struct device *dev,
static DEVICE_ATTR_RW(oscillator);
+static const int xt_freq_nom = 32768000; //Nominal XT frequency 32 kHz in mHz
+
+static int xt_frequency_set(struct i2c_client *client, u32 xt_freq)
+{
+ int retval;
+ long Adj;
+ union abx8xx_reg_cal_xt reg_cal_xt;
+ union abx8xx_reg_oss reg_oss;
+
+ retval = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
+ if (retval < 0)
+ goto err;
+ reg_oss.val = retval;
+
+ Adj = (xt_freq_nom - (int)xt_freq) * 16 / 1000;
+ if (Adj < -320) {
+ dev_err(&client->dev,
+ "The XT oscillator is too fast to be adjusted\n");
+ return -ERANGE;
+ } else if (Adj < -256) {
+ reg_oss.xtcal = 3;
+ reg_cal_xt.cmdx = 1;
+ reg_cal_xt.offsetx = (Adj + 192) / 2;
+ } else if (Adj < -192) {
+ reg_oss.xtcal = 3;
+ reg_cal_xt.cmdx = 0;
+ reg_cal_xt.offsetx = Adj + 192;
+ } else if (Adj < -128) {
+ reg_oss.xtcal = 2;
+ reg_cal_xt.cmdx = 0;
+ reg_cal_xt.offsetx = Adj + 128;
+ } else if (Adj < -64) {
+ reg_oss.xtcal = 1;
+ reg_cal_xt.cmdx = 0;
+ reg_cal_xt.offsetx = Adj + 64;
+ } else if (Adj < 64) {
+ reg_oss.xtcal = 0;
+ reg_cal_xt.cmdx = 0;
+ reg_cal_xt.offsetx = Adj;
+ } else if (Adj < 128) {
+ reg_oss.xtcal = 0;
+ reg_cal_xt.cmdx = 1;
+ reg_cal_xt.offsetx = Adj / 2;
+ } else {
+ dev_err(&client->dev,
+ "The XT oscillator is too slow to be adjusted\n");
+ return -ERANGE;
+ }
+
+ retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS,
+ reg_oss.val);
+ if (retval < 0)
+ goto err;
+
+ retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CAL_XT,
+ reg_cal_xt.val);
+ if (retval < 0)
+ goto err;
+
+ return 0;
+err:
+ dev_err(&client->dev, "Failed to access calibration data\n");
+ return retval;
+}
+
+static ssize_t xt_frequency_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int retval;
+ unsigned long xt_freq;
+
+ retval = kstrtoul(buf, 10, &xt_freq);
+ if (retval < 0) {
+ dev_err(dev, "Invalid value of oscillator frequency\n");
+ return -EINVAL;
+ }
+
+ dev_info(dev, "Computed xt osc drift is %li ppm\n",
+ 1000000l * ((long)xt_freq - xt_freq_nom) / xt_freq_nom);
+
+ retval = xt_frequency_set(to_i2c_client(dev->parent), xt_freq);
+ if (retval)
+ return retval;
+ return count;
+}
+
+static DEVICE_ATTR_WO(xt_frequency);
+
+static ssize_t xt_calibration_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int retval;
+ union abx8xx_reg_cal_xt reg_cal_xt;
+ union abx8xx_reg_oss reg_oss;
+ struct i2c_client *client = to_i2c_client(dev->parent);
+
+ retval = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
+ if (retval < 0)
+ goto err;
+ reg_oss.val = retval;
+
+ retval = i2c_smbus_read_byte_data(client, ABX8XX_REG_CAL_XT);
+ if (retval < 0)
+ goto err;
+ reg_cal_xt.val = retval;
+
+ return sprintf(buf, "XTCAL %x\nCMDX %x\nOFFSETX %i = 0x%lx\n",
+ reg_oss.xtcal, reg_cal_xt.cmdx, reg_cal_xt.offsetx,
+ reg_cal_xt.offsetx & ABX8XX_CAL_XT_OFFSETX_MASK);
+err:
+ dev_err(dev, "Failed to read calibration data\n");
+ sprintf(buf, "\n");
+ return retval;
+}
+static DEVICE_ATTR_RO(xt_calibration);
+
#define SQFS_COUNT (1 << ABX8XX_SQW_MODE_BITS)
/* The index of the array is the value to be written to the 'Square Wave Function
* Select' register to make the RTC generate the required square wave.
@@ -611,6 +747,8 @@ static struct attribute *rtc_calib_attrs[] = {
&dev_attr_autocalibration.attr,
&dev_attr_oscillator.attr,
&dev_attr_sqw.attr,
+ &dev_attr_xt_calibration.attr,
+ &dev_attr_xt_frequency.attr,
NULL,
};
@@ -809,6 +947,7 @@ static int abx80x_probe(struct i2c_client *client,
unsigned int wafer;
unsigned int uid;
const char *sqw_mode_name;
+ unsigned int xt_freq;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
@@ -923,6 +1062,12 @@ static int abx80x_probe(struct i2c_client *client,
abx80x_enable_trickle_charger(client, trickle_cfg);
}
+ if (!of_property_read_u32(np, "xt-frequency", &xt_freq)) {
+ dev_info(&client->dev, "Calibrate XT %d mHz:\n",
+ xt_freq);
+ xt_frequency_set(client, xt_freq);
+ }
+
if (!of_property_read_string(np, "sqw", &sqw_mode_name))
sqw_set(client, sqw_mode_name);
--
2.11.0
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH 4/4] rtc:abx80x: Enable xt digital calibration
2021-03-28 21:02 ` [PATCH 4/4] rtc:abx80x: Enable xt digital calibration Kirill Kapranov
@ 2021-04-09 10:46 ` Pavel Machek
2021-04-09 16:56 ` Kirill Kapranov
0 siblings, 1 reply; 11+ messages in thread
From: Pavel Machek @ 2021-04-09 10:46 UTC (permalink / raw)
To: Kirill Kapranov; +Cc: a.zummo, alexandre.belloni, phdm, linux-rtc, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 971 bytes --]
Hi!
> The XT digital calibration feature allows to improve the RTC accuracy,
> using a Distributed Digital Calibration function.
> See ch. 5.9.1 of AB08XX Series Ultra Low Power RTC IC User's Guide
> https://abracon.com/realtimeclock/AB08XX-Application-Manual.pdf
>
> Signed-off-by: Kirill Kapranov <kirill.kapranov@compulab.co.il>
> ---
> drivers/rtc/rtc-abx80x.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 145 insertions(+)
>
> +static const int xt_freq_nom = 32768000; //Nominal XT frequency 32 kHz in mHz
C-style comment?
is it 32 kHz or 32.768 kHz?
> +{
> + int retval;
> + long Adj;
Adj -> adj.
> +
> +static DEVICE_ATTR_WO(xt_frequency);
You are adding new user interface, you sould add documentation.
Best regards,
Pavel
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 181 bytes --]
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 4/4] rtc:abx80x: Enable xt digital calibration
2021-04-09 10:46 ` Pavel Machek
@ 2021-04-09 16:56 ` Kirill Kapranov
0 siblings, 0 replies; 11+ messages in thread
From: Kirill Kapranov @ 2021-04-09 16:56 UTC (permalink / raw)
To: Pavel Machek; +Cc: a.zummo, alexandre.belloni, phdm, linux-rtc, linux-kernel
Hi Pavel,
Thank you very much for pointing out the issues.
I redesign all the code deeply, as Alexandre Belloni suggested [1], and
the lines you have mentioned are to be fixed too.
Unfortunately, it takes more time than I supposed.
Thank you again!
--
Best Regards,
Kirill Kapranov
Software Engineer
CompuLab Ltd.
[1] https://marc.info/?l=linux-rtc&m=161696606727215&w=2
On 4/9/21 1:46 PM, Pavel Machek wrote:
> Hi!
>
>> The XT digital calibration feature allows to improve the RTC accuracy,
>> using a Distributed Digital Calibration function.
>> See ch. 5.9.1 of AB08XX Series Ultra Low Power RTC IC User's Guide
>> https://abracon.com/realtimeclock/AB08XX-Application-Manual.pdf
>>
>> Signed-off-by: Kirill Kapranov <kirill.kapranov@compulab.co.il>
>> ---
>> drivers/rtc/rtc-abx80x.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 145 insertions(+)
>
>
>>
>> +static const int xt_freq_nom = 32768000; //Nominal XT frequency 32 kHz in mHz
>
> C-style comment?
>
> is it 32 kHz or 32.768 kHz?
>
>> +{
>> + int retval;
>> + long Adj;
>
> Adj -> adj.
>
>> +
>> +static DEVICE_ATTR_WO(xt_frequency);
>
> You are adding new user interface, you sould add documentation.
>
> Best regards,
> Pavel
>
>
--
Best Regards,
Kirill Kapranov
Software Engineer
CompuLab Ltd.
Tel.: (+972) 48-290-100.Ext 227
Cel.: (+972) 53-9332508
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 0/4] rtc:abx80x: Enable distributed digital calibration
2021-03-28 21:02 [PATCH 0/4] rtc:abx80x: Enable distributed digital calibration Kirill Kapranov
` (3 preceding siblings ...)
2021-03-28 21:02 ` [PATCH 4/4] rtc:abx80x: Enable xt digital calibration Kirill Kapranov
@ 2021-03-28 21:14 ` Alexandre Belloni
4 siblings, 0 replies; 11+ messages in thread
From: Alexandre Belloni @ 2021-03-28 21:14 UTC (permalink / raw)
To: Kirill Kapranov; +Cc: a.zummo, phdm, linux-rtc, linux-kernel
Hello,
Thank you for working on that!
On 29/03/2021 00:02:28+0300, Kirill Kapranov wrote:
> This patch series enables a Distributed Digital Calibration function for
> the RTC of the family. This feature allows to improve the RTC accuracy by
> means of compensation an XT oscillator drift. To learn more, see:
> AB08XX Series Ultra Low Power RTC IC User's Guide
> https://abracon.com/realtimeclock/AB08XX-Application-Manual.pdf
>
> The patches 1 and 2 enable SQW output, that is necessary for subsequent
> measurement and computation. However, this feature may be enabled and used
> independently, as is.
>
Please use the common clock framework for this part. You will need a
dummy userspace user for this to work but I know Stephen is open to that
as we discussed that use case multiple times already.
> The patches 3 and 4 enable the XT calibration feature per se. The SQW
> output must be enabled for usage of this feature.
Please use the .set_offset and .get_offset rtc_ops for this part.
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
^ permalink raw reply [flat|nested] 11+ messages in thread