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 <[email protected]>
---
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
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 <[email protected]>
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/[email protected]
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 <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
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/[email protected]
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 <[email protected]>
> Reported-by: Dan Carpenter <[email protected]>
>
> 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/[email protected]
>