[PATCH v2 0/3] pinctrl: th1520: Improve code quality

[PATCH v2 0/3] pinctrl: th1520: Improve code quality

[Drew Fustini]

This series contains code quality improvements for the new TH1520
pinctrl driver [1]:

 - Fix smatch warning that the return value is not correctly set when an
   unknown pin error occurs
 - Linus suggested using guarded mutexs so I've converted the thp->mutex
   lock to that usage.
 - Linus also suggested using a scoped iterator for the DT for-each
   child node loop: for_each_available_child_of_node_scoped.

The series is based on the linusw devel branch [2].

[1] https://lore.kernel.org/lkml/CACRpkdavPAv2sPRREQhx_A7EtOj6Ld_n+NcO+vH0QCnfVedXKw@mail.gmail.com/
[2] https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl.git/log/?h=devel

Changes since v1:
- Move the scoped iterator conversion to a separate patch and remove the
  child put operations as they are no longer needed
- Link: https://lore.kernel.org/lkml/20241005-th1520-pinctrl-fixes-v1-0-5c65dffa0d00@tenstorrent.com/

Signed-off-by: Drew Fustini <dfustini@tenstorrent.com>
---
Drew Fustini (3):
      pinctrl: th1520: Fix return value for unknown pin error
      pinctrl: th1520: Convert thp->mutex to guarded mutex
      pinctrl: th1520: Convert dt child node loop to scoped iterator

 drivers/pinctrl/pinctrl-th1520.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)
---
base-commit: 2694868880705e8f6bb61b24b1b25adc42a4a217
change-id: 20241005-th1520-pinctrl-fixes-d20db68387e6

Best regards,
-- 
Drew Fustini <dfustini@tenstorrent.com>

[PATCH v2 1/3] pinctrl: th1520: Fix return value for unknown pin error

[Drew Fustini]

Fix th1520_pinctrl_dt_node_to_map() to set the return value before
jumping to free_configs when an unknown pin error occurs.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202410022336.xyWlV0Tf-lkp@intel.com/
Signed-off-by: Drew Fustini <dfustini@tenstorrent.com>
---
 drivers/pinctrl/pinctrl-th1520.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pinctrl/pinctrl-th1520.c b/drivers/pinctrl/pinctrl-th1520.c
index 9331f4462480..265a75a78d5a 100644
--- a/drivers/pinctrl/pinctrl-th1520.c
+++ b/drivers/pinctrl/pinctrl-th1520.c
@@ -499,6 +499,7 @@ static int th1520_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 				nmaps = rollback;
 				dev_err(thp->pctl->dev, "%pOFn.%pOFn: unknown pin '%s'\n",
 					np, child, pinname);
+				ret = -EINVAL;
 				goto free_configs;
 			}
 

-- 
2.34.1

[PATCH v2 2/3] pinctrl: th1520: Convert thp->mutex to guarded mutex

[Drew Fustini]

Convert th1520_pinctrl_dt_node_to_map() to use guarded mutex for
thp->mutex.

Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Drew Fustini <dfustini@tenstorrent.com>
---
 drivers/pinctrl/pinctrl-th1520.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-th1520.c b/drivers/pinctrl/pinctrl-th1520.c
index 265a75a78d5a..7ed3f82b9339 100644
--- a/drivers/pinctrl/pinctrl-th1520.c
+++ b/drivers/pinctrl/pinctrl-th1520.c
@@ -444,7 +444,7 @@ static int th1520_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 		return -ENOMEM;
 
 	nmaps = 0;
-	mutex_lock(&thp->mutex);
+	guard(mutex)(&thp->mutex);
 	for_each_available_child_of_node(np, child) {
 		unsigned int rollback = nmaps;
 		enum th1520_muxtype muxtype;
@@ -531,7 +531,6 @@ static int th1520_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 
 	*maps = map;
 	*num_maps = nmaps;
-	mutex_unlock(&thp->mutex);
 	return 0;
 
 free_configs:
@@ -539,7 +538,6 @@ static int th1520_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 put_child:
 	of_node_put(child);
 	th1520_pinctrl_dt_free_map(pctldev, map, nmaps);
-	mutex_unlock(&thp->mutex);
 	return ret;
 }
 

-- 
2.34.1

[PATCH v2 3/3] pinctrl: th1520: Convert dt child node loop to scoped iterator

[Drew Fustini]

Convert th1520_pinctrl_dt_node_to_map() to use a scoped iterator with
for_each_available_child_of_node_scoped(). As a result, there is no need
to call of_node_put() anymore. The put_child label has been renamed to
free_map which is now a more accurate description.

Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Drew Fustini <dfustini@tenstorrent.com>
---
 drivers/pinctrl/pinctrl-th1520.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-th1520.c b/drivers/pinctrl/pinctrl-th1520.c
index 7ed3f82b9339..286c6b2b0b13 100644
--- a/drivers/pinctrl/pinctrl-th1520.c
+++ b/drivers/pinctrl/pinctrl-th1520.c
@@ -425,11 +425,10 @@ static int th1520_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 	int ret;
 
 	nmaps = 0;
-	for_each_available_child_of_node(np, child) {
+	for_each_available_child_of_node_scoped(np, child) {
 		int npins = of_property_count_strings(child, "pins");
 
 		if (npins <= 0) {
-			of_node_put(child);
 			dev_err(thp->pctl->dev, "no pins selected for %pOFn.%pOFn\n",
 				np, child);
 			return -EINVAL;
@@ -445,7 +444,7 @@ static int th1520_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 
 	nmaps = 0;
 	guard(mutex)(&thp->mutex);
-	for_each_available_child_of_node(np, child) {
+	for_each_available_child_of_node_scoped(np, child) {
 		unsigned int rollback = nmaps;
 		enum th1520_muxtype muxtype;
 		struct property *prop;
@@ -458,7 +457,7 @@ static int th1520_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 		if (ret) {
 			dev_err(thp->pctl->dev, "%pOFn.%pOFn: error parsing pin config\n",
 				np, child);
-			goto put_child;
+			goto free_map;
 		}
 
 		if (!of_property_read_string(child, "function", &funcname)) {
@@ -524,7 +523,7 @@ static int th1520_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 							  npins, (void *)muxtype);
 			if (ret < 0) {
 				dev_err(thp->pctl->dev, "error adding function %s\n", funcname);
-				goto put_child;
+				goto free_map;
 			}
 		}
 	}
@@ -535,8 +534,7 @@ static int th1520_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
 
 free_configs:
 	kfree(configs);
-put_child:
-	of_node_put(child);
+free_map:
 	th1520_pinctrl_dt_free_map(pctldev, map, nmaps);
 	return ret;
 }

-- 
2.34.1

Re: [PATCH v2 3/3] pinctrl: th1520: Convert dt child node loop to scoped iterator

[kernel test robot]

Hi Drew,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 2694868880705e8f6bb61b24b1b25adc42a4a217]

url:    https://github.com/intel-lab-lkp/linux/commits/Drew-Fustini/pinctrl-th1520-Fix-return-value-for-unknown-pin-error/20241007-014953
base:   2694868880705e8f6bb61b24b1b25adc42a4a217
patch link:    https://lore.kernel.org/r/20241006-th1520-pinctrl-fixes-v2-3-b1822ae3a6d7%40tenstorrent.com
patch subject: [PATCH v2 3/3] pinctrl: th1520: Convert dt child node loop to scoped iterator
config: alpha-allyesconfig (https://download.01.org/0day-ci/archive/20241007/202410072033.XpRqZ8nz-lkp@intel.com/config)
compiler: alpha-linux-gcc (GCC) 13.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241007/202410072033.XpRqZ8nz-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410072033.XpRqZ8nz-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/pinctrl/pinctrl-th1520.c: In function 'th1520_pinctrl_dt_node_to_map':
>> drivers/pinctrl/pinctrl-th1520.c:420:29: warning: unused variable 'child' [-Wunused-variable]
     420 |         struct device_node *child;
         |                             ^~~~~


vim +/child +420 drivers/pinctrl/pinctrl-th1520.c

bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  413  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  414  static int th1520_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  415  					 struct device_node *np,
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  416  					 struct pinctrl_map **maps,
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  417  					 unsigned int *num_maps)
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  418  {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  419  	struct th1520_pinctrl *thp = pinctrl_dev_get_drvdata(pctldev);
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30 @420  	struct device_node *child;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  421  	struct pinctrl_map *map;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  422  	unsigned long *configs;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  423  	unsigned int nconfigs;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  424  	unsigned int nmaps;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  425  	int ret;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  426  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  427  	nmaps = 0;
1a1dcc4caac257 Drew Fustini         2024-10-06  428  	for_each_available_child_of_node_scoped(np, child) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  429  		int npins = of_property_count_strings(child, "pins");
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  430  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  431  		if (npins <= 0) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  432  			dev_err(thp->pctl->dev, "no pins selected for %pOFn.%pOFn\n",
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  433  				np, child);
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  434  			return -EINVAL;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  435  		}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  436  		nmaps += npins;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  437  		if (of_property_present(child, "function"))
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  438  			nmaps += npins;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  439  	}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  440  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  441  	map = kcalloc(nmaps, sizeof(*map), GFP_KERNEL);
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  442  	if (!map)
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  443  		return -ENOMEM;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  444  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  445  	nmaps = 0;
9aae170bf6c30e Drew Fustini         2024-10-06  446  	guard(mutex)(&thp->mutex);
1a1dcc4caac257 Drew Fustini         2024-10-06  447  	for_each_available_child_of_node_scoped(np, child) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  448  		unsigned int rollback = nmaps;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  449  		enum th1520_muxtype muxtype;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  450  		struct property *prop;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  451  		const char *funcname;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  452  		const char **pgnames;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  453  		const char *pinname;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  454  		int npins;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  455  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  456  		ret = pinconf_generic_parse_dt_config(child, pctldev, &configs, &nconfigs);
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  457  		if (ret) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  458  			dev_err(thp->pctl->dev, "%pOFn.%pOFn: error parsing pin config\n",
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  459  				np, child);
1a1dcc4caac257 Drew Fustini         2024-10-06  460  			goto free_map;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  461  		}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  462  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  463  		if (!of_property_read_string(child, "function", &funcname)) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  464  			muxtype = th1520_muxtype_get(funcname);
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  465  			if (!muxtype) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  466  				dev_err(thp->pctl->dev, "%pOFn.%pOFn: unknown function '%s'\n",
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  467  					np, child, funcname);
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  468  				ret = -EINVAL;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  469  				goto free_configs;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  470  			}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  471  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  472  			funcname = devm_kasprintf(thp->pctl->dev, GFP_KERNEL, "%pOFn.%pOFn",
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  473  						  np, child);
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  474  			if (!funcname) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  475  				ret = -ENOMEM;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  476  				goto free_configs;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  477  			}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  478  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  479  			npins = of_property_count_strings(child, "pins");
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  480  			pgnames = devm_kcalloc(thp->pctl->dev, npins, sizeof(*pgnames), GFP_KERNEL);
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  481  			if (!pgnames) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  482  				ret = -ENOMEM;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  483  				goto free_configs;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  484  			}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  485  		} else {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  486  			funcname = NULL;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  487  		}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  488  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  489  		npins = 0;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  490  		of_property_for_each_string(child, "pins", prop, pinname) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  491  			unsigned int i;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  492  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  493  			for (i = 0; i < thp->desc.npins; i++) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  494  				if (!strcmp(pinname, thp->desc.pins[i].name))
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  495  					break;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  496  			}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  497  			if (i == thp->desc.npins) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  498  				nmaps = rollback;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  499  				dev_err(thp->pctl->dev, "%pOFn.%pOFn: unknown pin '%s'\n",
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  500  					np, child, pinname);
08f5dfea548d37 Drew Fustini         2024-10-06  501  				ret = -EINVAL;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  502  				goto free_configs;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  503  			}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  504  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  505  			if (nconfigs) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  506  				map[nmaps].type = PIN_MAP_TYPE_CONFIGS_PIN;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  507  				map[nmaps].data.configs.group_or_pin = thp->desc.pins[i].name;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  508  				map[nmaps].data.configs.configs = configs;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  509  				map[nmaps].data.configs.num_configs = nconfigs;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  510  				nmaps += 1;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  511  			}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  512  			if (funcname) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  513  				pgnames[npins++] = thp->desc.pins[i].name;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  514  				map[nmaps].type = PIN_MAP_TYPE_MUX_GROUP;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  515  				map[nmaps].data.mux.function = funcname;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  516  				map[nmaps].data.mux.group = thp->desc.pins[i].name;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  517  				nmaps += 1;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  518  			}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  519  		}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  520  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  521  		if (funcname) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  522  			ret = pinmux_generic_add_function(pctldev, funcname, pgnames,
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  523  							  npins, (void *)muxtype);
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  524  			if (ret < 0) {
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  525  				dev_err(thp->pctl->dev, "error adding function %s\n", funcname);
1a1dcc4caac257 Drew Fustini         2024-10-06  526  				goto free_map;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  527  			}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  528  		}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  529  	}
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  530  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  531  	*maps = map;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  532  	*num_maps = nmaps;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  533  	return 0;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  534  
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  535  free_configs:
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  536  	kfree(configs);
1a1dcc4caac257 Drew Fustini         2024-10-06  537  free_map:
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  538  	th1520_pinctrl_dt_free_map(pctldev, map, nmaps);
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  539  	return ret;
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  540  }
bed5cd6f8a9883 Emil Renner Berthing 2024-09-30  541  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v2 3/3] pinctrl: th1520: Convert dt child node loop to scoped iterator

[Drew Fustini]

On Mon, Oct 07, 2024 at 08:26:28PM +0800, kernel test robot wrote:
> Hi Drew,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on 2694868880705e8f6bb61b24b1b25adc42a4a217]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Drew-Fustini/pinctrl-th1520-Fix-return-value-for-unknown-pin-error/20241007-014953
> base:   2694868880705e8f6bb61b24b1b25adc42a4a217
> patch link:    https://lore.kernel.org/r/20241006-th1520-pinctrl-fixes-v2-3-b1822ae3a6d7%40tenstorrent.com
> patch subject: [PATCH v2 3/3] pinctrl: th1520: Convert dt child node loop to scoped iterator
> config: alpha-allyesconfig (https://download.01.org/0day-ci/archive/20241007/202410072033.XpRqZ8nz-lkp@intel.com/config)
> compiler: alpha-linux-gcc (GCC) 13.3.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241007/202410072033.XpRqZ8nz-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202410072033.XpRqZ8nz-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>    drivers/pinctrl/pinctrl-th1520.c: In function 'th1520_pinctrl_dt_node_to_map':
> >> drivers/pinctrl/pinctrl-th1520.c:420:29: warning: unused variable 'child' [-Wunused-variable]
>      420 |         struct device_node *child;
>          |                             ^~~~~

It seems this is because the scoped iterator declares *child in the
macro and thus no separate declaration is needed:

 #define for_each_available_child_of_node_scoped(parent, child) \
         for (struct device_node *child __free(device_node) =            \
              of_get_next_available_child(parent, NULL);                 \
              child != NULL;                                             \
              child = of_get_next_available_child(parent, child))

I'll fix in next revision.

Thanks,
Drew