1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * printer.c -- Printer gadget driver
4  *
5  * Copyright (C) 2003-2005 David Brownell
6  * Copyright (C) 2006 Craig W. Nadler
7  */
8 
9 #include <linux/module.h>
10 #include <linux/kernel.h>
11 #include <asm/byteorder.h>
12 
13 #include <linux/usb/ch9.h>
14 #include <linux/usb/composite.h>
15 #include <linux/usb/gadget.h>
16 #include <linux/usb/g_printer.h>
17 
18 USB_GADGET_COMPOSITE_OPTIONS();
19 
20 #define DRIVER_DESC		"Printer Gadget"
21 #define DRIVER_VERSION		"2015 FEB 17"
22 
23 static const char shortname [] = "printer";
24 
25 #include "u_printer.h"
26 
27 /*-------------------------------------------------------------------------*/
28 
29 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
30  * Instead:  allocate your own, using normal USB-IF procedures.
31  */
32 
33 /* Thanks to NetChip Technologies for donating this product ID.
34  */
35 #define PRINTER_VENDOR_NUM	0x0525		/* NetChip */
36 #define PRINTER_PRODUCT_NUM	0xa4a8		/* Linux-USB Printer Gadget */
37 
38 /* Some systems will want different product identifiers published in the
39  * device descriptor, either numbers or strings or both.  These string
40  * parameters are in UTF-8 (superset of ASCII's 7 bit characters).
41  */
42 
43 module_param_named(iSerialNum, coverwrite.serial_number, charp, S_IRUGO);
44 MODULE_PARM_DESC(iSerialNum, "1");
45 
46 static char *iPNPstring;
47 module_param(iPNPstring, charp, S_IRUGO);
48 MODULE_PARM_DESC(iPNPstring, "MFG:linux;MDL:g_printer;CLS:PRINTER;SN:1;");
49 
50 /* Number of requests to allocate per endpoint, not used for ep0. */
51 static unsigned qlen = 10;
52 module_param(qlen, uint, S_IRUGO|S_IWUSR);
53 MODULE_PARM_DESC(qlen, "The number of 8k buffers to use per endpoint");
54 
55 #define QLEN	qlen
56 
57 static struct usb_function_instance *fi_printer;
58 static struct usb_function *f_printer;
59 
60 /*-------------------------------------------------------------------------*/
61 
62 /*
63  * DESCRIPTORS ... most are static, but strings and (full) configuration
64  * descriptors are built on demand.
65  */
66 
67 static struct usb_device_descriptor device_desc = {
68 	.bLength =		sizeof device_desc,
69 	.bDescriptorType =	USB_DT_DEVICE,
70 	/* .bcdUSB = DYNAMIC */
71 	.bDeviceClass =		USB_CLASS_PER_INTERFACE,
72 	.bDeviceSubClass =	0,
73 	.bDeviceProtocol =	0,
74 	.idVendor =		cpu_to_le16(PRINTER_VENDOR_NUM),
75 	.idProduct =		cpu_to_le16(PRINTER_PRODUCT_NUM),
76 	.bNumConfigurations =	1
77 };
78 
79 static const struct usb_descriptor_header *otg_desc[2];
80 
81 /*-------------------------------------------------------------------------*/
82 
83 /* descriptors that are built on-demand */
84 
85 static char				product_desc [40] = DRIVER_DESC;
86 static char				serial_num [40] = "1";
87 static char				*pnp_string =
88 	"MFG:linux;MDL:g_printer;CLS:PRINTER;SN:1;";
89 
90 /* static strings, in UTF-8 */
91 static struct usb_string		strings [] = {
92 	[USB_GADGET_MANUFACTURER_IDX].s = "",
93 	[USB_GADGET_PRODUCT_IDX].s = product_desc,
94 	[USB_GADGET_SERIAL_IDX].s =	serial_num,
95 	{  }		/* end of list */
96 };
97 
98 static struct usb_gadget_strings	stringtab_dev = {
99 	.language	= 0x0409,	/* en-us */
100 	.strings	= strings,
101 };
102 
103 static struct usb_gadget_strings *dev_strings[] = {
104 	&stringtab_dev,
105 	NULL,
106 };
107 
108 static struct usb_configuration printer_cfg_driver = {
109 	.label			= "printer",
110 	.bConfigurationValue	= 1,
111 	.bmAttributes		= USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
112 };
113 
114 static int printer_do_config(struct usb_configuration *c)
115 {
116 	struct usb_gadget	*gadget = c->cdev->gadget;
117 	int			status = 0;
118 
119 	usb_ep_autoconfig_reset(gadget);
120 
121 	usb_gadget_set_selfpowered(gadget);
122 
123 	if (gadget_is_otg(gadget)) {
124 		printer_cfg_driver.descriptors = otg_desc;
125 		printer_cfg_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
126 	}
127 
128 	f_printer = usb_get_function(fi_printer);
129 	if (IS_ERR(f_printer))
130 		return PTR_ERR(f_printer);
131 
132 	status = usb_add_function(c, f_printer);
133 	if (status < 0)
134 		usb_put_function(f_printer);
135 
136 	return status;
137 }
138 
139 static int printer_bind(struct usb_composite_dev *cdev)
140 {
141 	struct f_printer_opts *opts;
142 	int ret;
143 
144 	fi_printer = usb_get_function_instance("printer");
145 	if (IS_ERR(fi_printer))
146 		return PTR_ERR(fi_printer);
147 
148 	opts = container_of(fi_printer, struct f_printer_opts, func_inst);
149 	opts->minor = 0;
150 	opts->q_len = QLEN;
151 	if (iPNPstring) {
152 		opts->pnp_string = kstrdup(iPNPstring, GFP_KERNEL);
153 		if (!opts->pnp_string) {
154 			ret = -ENOMEM;
155 			goto fail_put_func_inst;
156 		}
157 		opts->pnp_string_allocated = true;
158 		/*
159 		 * we don't free this memory in case of error
160 		 * as printer cleanup func will do this for us
161 		 */
162 	} else {
163 		opts->pnp_string = pnp_string;
164 	}
165 
166 	ret = usb_string_ids_tab(cdev, strings);
167 	if (ret < 0)
168 		goto fail_put_func_inst;
169 
170 	device_desc.iManufacturer = strings[USB_GADGET_MANUFACTURER_IDX].id;
171 	device_desc.iProduct = strings[USB_GADGET_PRODUCT_IDX].id;
172 	device_desc.iSerialNumber = strings[USB_GADGET_SERIAL_IDX].id;
173 
174 	if (gadget_is_otg(cdev->gadget) && !otg_desc[0]) {
175 		struct usb_descriptor_header *usb_desc;
176 
177 		usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
178 		if (!usb_desc) {
179 			ret = -ENOMEM;
180 			goto fail_put_func_inst;
181 		}
182 		usb_otg_descriptor_init(cdev->gadget, usb_desc);
183 		otg_desc[0] = usb_desc;
184 		otg_desc[1] = NULL;
185 	}
186 
187 	ret = usb_add_config(cdev, &printer_cfg_driver, printer_do_config);
188 	if (ret)
189 		goto fail_free_otg_desc;
190 
191 	usb_composite_overwrite_options(cdev, &coverwrite);
192 	return ret;
193 
194 fail_free_otg_desc:
195 	kfree(otg_desc[0]);
196 	otg_desc[0] = NULL;
197 fail_put_func_inst:
198 	usb_put_function_instance(fi_printer);
199 	return ret;
200 }
201 
202 static int printer_unbind(struct usb_composite_dev *cdev)
203 {
204 	usb_put_function(f_printer);
205 	usb_put_function_instance(fi_printer);
206 
207 	kfree(otg_desc[0]);
208 	otg_desc[0] = NULL;
209 
210 	return 0;
211 }
212 
213 static struct usb_composite_driver printer_driver = {
214 	.name           = shortname,
215 	.dev            = &device_desc,
216 	.strings        = dev_strings,
217 	.max_speed      = USB_SPEED_SUPER,
218 	.bind		= printer_bind,
219 	.unbind		= printer_unbind,
220 };
221 
222 module_usb_composite_driver(printer_driver);
223 
224 MODULE_DESCRIPTION(DRIVER_DESC);
225 MODULE_AUTHOR("Craig Nadler");
226 MODULE_LICENSE("GPL");
227