Re: [PATCHv3 4/4] wiegand: add Wiegand GPIO bitbanged controller driver

From: kernel test robot
Date: Wed Mar 01 2023 - 21:13:07 EST


Hi Martin,

I love your patch! Perhaps something to improve:

[auto build test WARNING on robh/for-next]
[also build test WARNING on linus/master v6.2 next-20230301]
[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#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Martin-Za-ovi/dt-bindings-wiegand-add-Wiegand-controller-common-properties/20230301-223030
base: https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
patch link: https://lore.kernel.org/r/20230301142835.19614-5-m.zatovic1%40gmail.com
patch subject: [PATCHv3 4/4] wiegand: add Wiegand GPIO bitbanged controller driver
config: sh-allmodconfig (https://download.01.org/0day-ci/archive/20230302/202303020937.pxOPT5nt-lkp@xxxxxxxxx/config)
compiler: sh4-linux-gcc (GCC) 12.1.0
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
# https://github.com/intel-lab-lkp/linux/commit/641c36b9878a19ea4977f0e14df22c7475b423df
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Martin-Za-ovi/dt-bindings-wiegand-add-Wiegand-controller-common-properties/20230301-223030
git checkout 641c36b9878a19ea4977f0e14df22c7475b423df
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=sh olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=sh SHELL=/bin/bash drivers/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Link: https://lore.kernel.org/oe-kbuild-all/202303020937.pxOPT5nt-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

>> drivers/wiegand/wiegand-gpio.c:50:9: warning: no previous prototype for 'payload_len_show' [-Wmissing-prototypes]
50 | ssize_t payload_len_show(struct device *dev, struct device_attribute *attr, char *buf)
| ^~~~~~~~~~~~~~~~
>> drivers/wiegand/wiegand-gpio.c:58:9: warning: no previous prototype for 'payload_len_store' [-Wmissing-prototypes]
58 | ssize_t payload_len_store(struct device *dev, struct device_attribute *attr, const char *buf,
| ^~~~~~~~~~~~~~~~~
>> drivers/wiegand/wiegand-gpio.c:81:6: warning: no previous prototype for 'wiegand_gpio_send_bit' [-Wmissing-prototypes]
81 | void wiegand_gpio_send_bit(struct wiegand_gpio *wiegand_gpio, bool value, bool last)
| ^~~~~~~~~~~~~~~~~~~~~
>> drivers/wiegand/wiegand-gpio.c:195:5: warning: no previous prototype for 'wiegand_gpio_transfer_message' [-Wmissing-prototypes]
195 | int wiegand_gpio_transfer_message(struct wiegand_device *dev, u8 *message, u8 msg_bitlen)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/payload_len_show +50 drivers/wiegand/wiegand-gpio.c

46
47 /*
48 * Attribute file for setting payload length of Wiegand messages.
49 */
> 50 ssize_t payload_len_show(struct device *dev, struct device_attribute *attr, char *buf)
51 {
52 struct wiegand_gpio *wiegand_gpio = dev_get_drvdata(dev);
53 struct wiegand_controller *ctlr = wiegand_gpio->ctlr;
54
55 return sysfs_emit(buf, "%u\n", ctlr->payload_len);
56 }
57
> 58 ssize_t payload_len_store(struct device *dev, struct device_attribute *attr, const char *buf,
59 size_t count)
60 {
61 struct wiegand_gpio *wiegand_gpio = dev_get_drvdata(dev);
62 struct wiegand_controller *ctlr = wiegand_gpio->ctlr;
63
64 return store_ulong(&(ctlr->payload_len), buf, count, WIEGAND_MAX_PAYLEN_BYTES * 8);
65 }
66 DEVICE_ATTR_RW(payload_len);
67
68 static struct attribute *wiegand_gpio_attrs[] = {
69 &dev_attr_payload_len.attr,
70 NULL,
71 };
72
73 ATTRIBUTE_GROUPS(wiegand_gpio);
74
75 /*
76 * To send a bit of value 1 following the wiegand protocol, one must set
77 * the wiegand_data_hi to low for the duration of pulse. Similarly to send
78 * a bit of value 0, the wiegand_data_lo is set to low for pulse duration.
79 * This way the two lines are never low at the same time.
80 */
> 81 void wiegand_gpio_send_bit(struct wiegand_gpio *wiegand_gpio, bool value, bool last)
82 {
83 u32 pulse_len = wiegand_gpio->ctlr->pulse_len;
84 u32 interval_len = wiegand_gpio->ctlr->interval_len;
85 u32 frame_gap = wiegand_gpio->ctlr->frame_gap;
86 struct gpio_desc *gpio = value ? wiegand_gpio->gpio_data_hi : wiegand_gpio->gpio_data_lo;
87
88 gpiod_set_value_cansleep(gpio, 0);
89 udelay(pulse_len);
90 gpiod_set_value_cansleep(gpio, 1);
91
92 if (last)
93 udelay(frame_gap - pulse_len);
94 else
95 udelay(interval_len - pulse_len);
96 }
97
98 /* This function is used for writing from file in dev directory */
99 static int wiegand_gpio_write_by_bits(struct wiegand_gpio *wiegand_gpio, u16 bitlen)
100 {
101 size_t i;
102 bool bit_value, is_last_bit;
103
104 for (i = 0; i < bitlen; i++) {
105 bit_value = ((wiegand_gpio->data[i / 8] >> (7 - (i % 8))) & 0x01);
106 is_last_bit = (i + 1) == bitlen;
107 wiegand_gpio_send_bit(wiegand_gpio, bit_value, is_last_bit);
108 }
109
110 return 0;
111 }
112
113 static ssize_t wiegand_gpio_get_user_data(struct wiegand_gpio *wiegand_gpio, char __user const *buf,
114 size_t len)
115 {
116 size_t rc;
117
118 if (len > WIEGAND_MAX_PAYLEN_BYTES)
119 return -EBADMSG;
120
121 rc = copy_from_user(&wiegand_gpio->data[0], buf, WIEGAND_MAX_PAYLEN_BYTES);
122 if (rc < 0)
123 return rc;
124
125 return len;
126 }
127
128 static int wiegand_gpio_frelease(struct inode *ino, struct file *filp)
129 {
130 struct wiegand_gpio_instance *info = filp->private_data;
131 struct wiegand_gpio *wiegand_gpio = info->dev;
132
133 mutex_lock(&wiegand_gpio->mutex);
134 info->flags = 0;
135 mutex_unlock(&wiegand_gpio->mutex);
136
137 kfree(info);
138
139 return 0;
140 }
141
142 static ssize_t wiegand_gpio_fwrite(struct file *filp, char __user const *buf, size_t len,
143 loff_t *offset)
144 {
145 struct wiegand_gpio_instance *info = filp->private_data;
146 struct wiegand_gpio *wiegand_gpio = info->dev;
147 u32 msg_length = wiegand_gpio->ctlr->payload_len;
148 int rc;
149
150 if (buf == NULL || len == 0 || len * 8 < msg_length)
151 return -EINVAL;
152
153 rc = wiegand_gpio_get_user_data(wiegand_gpio, buf, len);
154 if (rc < 0)
155 return rc;
156
157 wiegand_gpio_write_by_bits(wiegand_gpio, msg_length);
158
159 return len;
160 }
161
162 static int wiegand_gpio_fopen(struct inode *ino, struct file *filp)
163 {
164 int rc;
165 struct wiegand_gpio_instance *info;
166 struct wiegand_gpio *wiegand_gpio = container_of(filp->f_op, struct wiegand_gpio, fops);
167
168 mutex_lock(&wiegand_gpio->mutex);
169
170 if ((filp->f_flags & O_ACCMODE) == O_RDONLY || (filp->f_flags & O_ACCMODE) == O_RDWR) {
171 dev_err(wiegand_gpio->dev, "Device is write only\n");
172 rc = -EIO;
173 goto err;
174 }
175
176 info = kzalloc(sizeof(*info), GFP_KERNEL);
177 if (!info) {
178 rc = -ENOMEM;
179 goto err;
180 }
181
182 info->dev = wiegand_gpio;
183 info->flags = filp->f_flags;
184 mutex_unlock(&wiegand_gpio->mutex);
185
186 filp->private_data = info;
187
188 return 0;
189 err:
190 mutex_unlock(&wiegand_gpio->mutex);
191 return rc;
192 }
193
194 /* This function is used by device drivers */
> 195 int wiegand_gpio_transfer_message(struct wiegand_device *dev, u8 *message, u8 msg_bitlen)
196 {
197 struct wiegand_controller *ctlr = dev->controller;
198 struct wiegand_gpio *wiegand_gpio = wiegand_master_get_devdata(ctlr);
199 u8 msg_bytelength = (msg_bitlen % 8) ? (msg_bitlen / 8) + 1 : (msg_bitlen / 8);
200
201 memcpy(wiegand_gpio->data, message, msg_bytelength);
202 wiegand_gpio_write_by_bits(wiegand_gpio, msg_bitlen);
203
204 return 0;
205 }
206

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https://github.com/intel/lkp-tests