1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * nokia-modem.c
4 *
5 * HSI client driver for Nokia N900 modem.
6 *
7 * Copyright (C) 2014 Sebastian Reichel <sre@kernel.org>
8 */
9
10 #include <linux/gpio/consumer.h>
11 #include <linux/hsi/hsi.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/of.h>
15 #include <linux/of_irq.h>
16 #include <linux/hsi/ssi_protocol.h>
17
18 static unsigned int pm = 1;
19 module_param(pm, int, 0400);
20 MODULE_PARM_DESC(pm,
21 "Enable power management (0=disabled, 1=userland based [default])");
22
23 struct nokia_modem_gpio {
24 struct gpio_desc *gpio;
25 const char *name;
26 };
27
28 struct nokia_modem_device {
29 struct tasklet_struct nokia_modem_rst_ind_tasklet;
30 int nokia_modem_rst_ind_irq;
31 struct device *device;
32 struct nokia_modem_gpio *gpios;
33 int gpio_amount;
34 struct hsi_client *ssi_protocol;
35 struct hsi_client *cmt_speech;
36 };
37
do_nokia_modem_rst_ind_tasklet(unsigned long data)38 static void do_nokia_modem_rst_ind_tasklet(unsigned long data)
39 {
40 struct nokia_modem_device *modem = (struct nokia_modem_device *)data;
41
42 if (!modem)
43 return;
44
45 dev_info(modem->device, "CMT rst line change detected\n");
46
47 if (modem->ssi_protocol)
48 ssip_reset_event(modem->ssi_protocol);
49 }
50
nokia_modem_rst_ind_isr(int irq,void * data)51 static irqreturn_t nokia_modem_rst_ind_isr(int irq, void *data)
52 {
53 struct nokia_modem_device *modem = (struct nokia_modem_device *)data;
54
55 tasklet_schedule(&modem->nokia_modem_rst_ind_tasklet);
56
57 return IRQ_HANDLED;
58 }
59
nokia_modem_gpio_unexport(struct device * dev)60 static void nokia_modem_gpio_unexport(struct device *dev)
61 {
62 struct nokia_modem_device *modem = dev_get_drvdata(dev);
63 int i;
64
65 for (i = 0; i < modem->gpio_amount; i++) {
66 sysfs_remove_link(&dev->kobj, modem->gpios[i].name);
67 gpiod_unexport(modem->gpios[i].gpio);
68 }
69 }
70
nokia_modem_gpio_probe(struct device * dev)71 static int nokia_modem_gpio_probe(struct device *dev)
72 {
73 struct device_node *np = dev->of_node;
74 struct nokia_modem_device *modem = dev_get_drvdata(dev);
75 int gpio_count, gpio_name_count, i, err;
76
77 gpio_count = gpiod_count(dev, NULL);
78 if (gpio_count < 0) {
79 dev_err(dev, "missing gpios: %d\n", gpio_count);
80 return gpio_count;
81 }
82
83 gpio_name_count = of_property_count_strings(np, "gpio-names");
84
85 if (gpio_count != gpio_name_count) {
86 dev_err(dev, "number of gpios does not equal number of gpio names\n");
87 return -EINVAL;
88 }
89
90 modem->gpios = devm_kcalloc(dev, gpio_count, sizeof(*modem->gpios),
91 GFP_KERNEL);
92 if (!modem->gpios)
93 return -ENOMEM;
94
95 modem->gpio_amount = gpio_count;
96
97 for (i = 0; i < gpio_count; i++) {
98 modem->gpios[i].gpio = devm_gpiod_get_index(dev, NULL, i,
99 GPIOD_OUT_LOW);
100 if (IS_ERR(modem->gpios[i].gpio)) {
101 dev_err(dev, "Could not get gpio %d\n", i);
102 return PTR_ERR(modem->gpios[i].gpio);
103 }
104
105 err = of_property_read_string_index(np, "gpio-names", i,
106 &(modem->gpios[i].name));
107 if (err) {
108 dev_err(dev, "Could not get gpio name %d\n", i);
109 return err;
110 }
111
112 err = gpiod_export(modem->gpios[i].gpio, 0);
113 if (err)
114 return err;
115
116 err = gpiod_export_link(dev, modem->gpios[i].name,
117 modem->gpios[i].gpio);
118 if (err)
119 return err;
120 }
121
122 return 0;
123 }
124
nokia_modem_probe(struct device * dev)125 static int nokia_modem_probe(struct device *dev)
126 {
127 struct device_node *np;
128 struct nokia_modem_device *modem;
129 struct hsi_client *cl = to_hsi_client(dev);
130 struct hsi_port *port = hsi_get_port(cl);
131 int irq, pflags, err;
132 struct hsi_board_info ssip;
133 struct hsi_board_info cmtspeech;
134
135 np = dev->of_node;
136 if (!np) {
137 dev_err(dev, "device tree node not found\n");
138 return -ENXIO;
139 }
140
141 modem = devm_kzalloc(dev, sizeof(*modem), GFP_KERNEL);
142 if (!modem)
143 return -ENOMEM;
144
145 dev_set_drvdata(dev, modem);
146 modem->device = dev;
147
148 irq = irq_of_parse_and_map(np, 0);
149 if (!irq) {
150 dev_err(dev, "Invalid rst_ind interrupt (%d)\n", irq);
151 return -EINVAL;
152 }
153 modem->nokia_modem_rst_ind_irq = irq;
154 pflags = irq_get_trigger_type(irq);
155
156 tasklet_init(&modem->nokia_modem_rst_ind_tasklet,
157 do_nokia_modem_rst_ind_tasklet, (unsigned long)modem);
158 err = devm_request_irq(dev, irq, nokia_modem_rst_ind_isr,
159 pflags, "modem_rst_ind", modem);
160 if (err < 0) {
161 dev_err(dev, "Request rst_ind irq(%d) failed (flags %d)\n",
162 irq, pflags);
163 return err;
164 }
165 enable_irq_wake(irq);
166
167 if (pm) {
168 err = nokia_modem_gpio_probe(dev);
169 if (err < 0) {
170 dev_err(dev, "Could not probe GPIOs\n");
171 goto error1;
172 }
173 }
174
175 ssip.name = "ssi-protocol";
176 ssip.tx_cfg = cl->tx_cfg;
177 ssip.rx_cfg = cl->rx_cfg;
178 ssip.platform_data = NULL;
179 ssip.archdata = NULL;
180
181 modem->ssi_protocol = hsi_new_client(port, &ssip);
182 if (!modem->ssi_protocol) {
183 dev_err(dev, "Could not register ssi-protocol device\n");
184 err = -ENOMEM;
185 goto error2;
186 }
187
188 err = device_attach(&modem->ssi_protocol->device);
189 if (err == 0) {
190 dev_dbg(dev, "Missing ssi-protocol driver\n");
191 err = -EPROBE_DEFER;
192 goto error3;
193 } else if (err < 0) {
194 dev_err(dev, "Could not load ssi-protocol driver (%d)\n", err);
195 goto error3;
196 }
197
198 cmtspeech.name = "cmt-speech";
199 cmtspeech.tx_cfg = cl->tx_cfg;
200 cmtspeech.rx_cfg = cl->rx_cfg;
201 cmtspeech.platform_data = NULL;
202 cmtspeech.archdata = NULL;
203
204 modem->cmt_speech = hsi_new_client(port, &cmtspeech);
205 if (!modem->cmt_speech) {
206 dev_err(dev, "Could not register cmt-speech device\n");
207 err = -ENOMEM;
208 goto error3;
209 }
210
211 err = device_attach(&modem->cmt_speech->device);
212 if (err == 0) {
213 dev_dbg(dev, "Missing cmt-speech driver\n");
214 err = -EPROBE_DEFER;
215 goto error4;
216 } else if (err < 0) {
217 dev_err(dev, "Could not load cmt-speech driver (%d)\n", err);
218 goto error4;
219 }
220
221 dev_info(dev, "Registered Nokia HSI modem\n");
222
223 return 0;
224
225 error4:
226 hsi_remove_client(&modem->cmt_speech->device, NULL);
227 error3:
228 hsi_remove_client(&modem->ssi_protocol->device, NULL);
229 error2:
230 nokia_modem_gpio_unexport(dev);
231 error1:
232 disable_irq_wake(modem->nokia_modem_rst_ind_irq);
233 tasklet_kill(&modem->nokia_modem_rst_ind_tasklet);
234
235 return err;
236 }
237
nokia_modem_remove(struct device * dev)238 static int nokia_modem_remove(struct device *dev)
239 {
240 struct nokia_modem_device *modem = dev_get_drvdata(dev);
241
242 if (!modem)
243 return 0;
244
245 if (modem->cmt_speech) {
246 hsi_remove_client(&modem->cmt_speech->device, NULL);
247 modem->cmt_speech = NULL;
248 }
249
250 if (modem->ssi_protocol) {
251 hsi_remove_client(&modem->ssi_protocol->device, NULL);
252 modem->ssi_protocol = NULL;
253 }
254
255 nokia_modem_gpio_unexport(dev);
256 dev_set_drvdata(dev, NULL);
257 disable_irq_wake(modem->nokia_modem_rst_ind_irq);
258 tasklet_kill(&modem->nokia_modem_rst_ind_tasklet);
259
260 return 0;
261 }
262
263 #ifdef CONFIG_OF
264 static const struct of_device_id nokia_modem_of_match[] = {
265 { .compatible = "nokia,n900-modem", },
266 { .compatible = "nokia,n950-modem", },
267 { .compatible = "nokia,n9-modem", },
268 {},
269 };
270 MODULE_DEVICE_TABLE(of, nokia_modem_of_match);
271 #endif
272
273 static struct hsi_client_driver nokia_modem_driver = {
274 .driver = {
275 .name = "nokia-modem",
276 .owner = THIS_MODULE,
277 .probe = nokia_modem_probe,
278 .remove = nokia_modem_remove,
279 .of_match_table = of_match_ptr(nokia_modem_of_match),
280 },
281 };
282
nokia_modem_init(void)283 static int __init nokia_modem_init(void)
284 {
285 return hsi_register_client_driver(&nokia_modem_driver);
286 }
287 module_init(nokia_modem_init);
288
nokia_modem_exit(void)289 static void __exit nokia_modem_exit(void)
290 {
291 hsi_unregister_client_driver(&nokia_modem_driver);
292 }
293 module_exit(nokia_modem_exit);
294
295 MODULE_ALIAS("hsi:nokia-modem");
296 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
297 MODULE_DESCRIPTION("HSI driver module for Nokia N900 Modem");
298 MODULE_LICENSE("GPL");
299