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/of_gpio.h>
17 #include <linux/hsi/ssi_protocol.h>
18
19 static unsigned int pm = 1;
20 module_param(pm, int, 0400);
21 MODULE_PARM_DESC(pm,
22 "Enable power management (0=disabled, 1=userland based [default])");
23
24 struct nokia_modem_gpio {
25 struct gpio_desc *gpio;
26 const char *name;
27 };
28
29 struct nokia_modem_device {
30 struct tasklet_struct nokia_modem_rst_ind_tasklet;
31 int nokia_modem_rst_ind_irq;
32 struct device *device;
33 struct nokia_modem_gpio *gpios;
34 int gpio_amount;
35 struct hsi_client *ssi_protocol;
36 struct hsi_client *cmt_speech;
37 };
38
do_nokia_modem_rst_ind_tasklet(unsigned long data)39 static void do_nokia_modem_rst_ind_tasklet(unsigned long data)
40 {
41 struct nokia_modem_device *modem = (struct nokia_modem_device *)data;
42
43 if (!modem)
44 return;
45
46 dev_info(modem->device, "CMT rst line change detected\n");
47
48 if (modem->ssi_protocol)
49 ssip_reset_event(modem->ssi_protocol);
50 }
51
nokia_modem_rst_ind_isr(int irq,void * data)52 static irqreturn_t nokia_modem_rst_ind_isr(int irq, void *data)
53 {
54 struct nokia_modem_device *modem = (struct nokia_modem_device *)data;
55
56 tasklet_schedule(&modem->nokia_modem_rst_ind_tasklet);
57
58 return IRQ_HANDLED;
59 }
60
nokia_modem_gpio_unexport(struct device * dev)61 static void nokia_modem_gpio_unexport(struct device *dev)
62 {
63 struct nokia_modem_device *modem = dev_get_drvdata(dev);
64 int i;
65
66 for (i = 0; i < modem->gpio_amount; i++) {
67 sysfs_remove_link(&dev->kobj, modem->gpios[i].name);
68 gpiod_unexport(modem->gpios[i].gpio);
69 }
70 }
71
nokia_modem_gpio_probe(struct device * dev)72 static int nokia_modem_gpio_probe(struct device *dev)
73 {
74 struct device_node *np = dev->of_node;
75 struct nokia_modem_device *modem = dev_get_drvdata(dev);
76 int gpio_count, gpio_name_count, i, err;
77
78 gpio_count = of_gpio_count(np);
79
80 if (gpio_count < 0) {
81 dev_err(dev, "missing gpios: %d\n", gpio_count);
82 return gpio_count;
83 }
84
85 gpio_name_count = of_property_count_strings(np, "gpio-names");
86
87 if (gpio_count != gpio_name_count) {
88 dev_err(dev, "number of gpios does not equal number of gpio names\n");
89 return -EINVAL;
90 }
91
92 modem->gpios = devm_kcalloc(dev, gpio_count, sizeof(*modem->gpios),
93 GFP_KERNEL);
94 if (!modem->gpios)
95 return -ENOMEM;
96
97 modem->gpio_amount = gpio_count;
98
99 for (i = 0; i < gpio_count; i++) {
100 modem->gpios[i].gpio = devm_gpiod_get_index(dev, NULL, i,
101 GPIOD_OUT_LOW);
102 if (IS_ERR(modem->gpios[i].gpio)) {
103 dev_err(dev, "Could not get gpio %d\n", i);
104 return PTR_ERR(modem->gpios[i].gpio);
105 }
106
107 err = of_property_read_string_index(np, "gpio-names", i,
108 &(modem->gpios[i].name));
109 if (err) {
110 dev_err(dev, "Could not get gpio name %d\n", i);
111 return err;
112 }
113
114 err = gpiod_export(modem->gpios[i].gpio, 0);
115 if (err)
116 return err;
117
118 err = gpiod_export_link(dev, modem->gpios[i].name,
119 modem->gpios[i].gpio);
120 if (err)
121 return err;
122 }
123
124 return 0;
125 }
126
nokia_modem_probe(struct device * dev)127 static int nokia_modem_probe(struct device *dev)
128 {
129 struct device_node *np;
130 struct nokia_modem_device *modem;
131 struct hsi_client *cl = to_hsi_client(dev);
132 struct hsi_port *port = hsi_get_port(cl);
133 int irq, pflags, err;
134 struct hsi_board_info ssip;
135 struct hsi_board_info cmtspeech;
136
137 np = dev->of_node;
138 if (!np) {
139 dev_err(dev, "device tree node not found\n");
140 return -ENXIO;
141 }
142
143 modem = devm_kzalloc(dev, sizeof(*modem), GFP_KERNEL);
144 if (!modem)
145 return -ENOMEM;
146
147 dev_set_drvdata(dev, modem);
148 modem->device = dev;
149
150 irq = irq_of_parse_and_map(np, 0);
151 if (!irq) {
152 dev_err(dev, "Invalid rst_ind interrupt (%d)\n", irq);
153 return -EINVAL;
154 }
155 modem->nokia_modem_rst_ind_irq = irq;
156 pflags = irq_get_trigger_type(irq);
157
158 tasklet_init(&modem->nokia_modem_rst_ind_tasklet,
159 do_nokia_modem_rst_ind_tasklet, (unsigned long)modem);
160 err = devm_request_irq(dev, irq, nokia_modem_rst_ind_isr,
161 pflags, "modem_rst_ind", modem);
162 if (err < 0) {
163 dev_err(dev, "Request rst_ind irq(%d) failed (flags %d)\n",
164 irq, pflags);
165 return err;
166 }
167 enable_irq_wake(irq);
168
169 if (pm) {
170 err = nokia_modem_gpio_probe(dev);
171 if (err < 0) {
172 dev_err(dev, "Could not probe GPIOs\n");
173 goto error1;
174 }
175 }
176
177 ssip.name = "ssi-protocol";
178 ssip.tx_cfg = cl->tx_cfg;
179 ssip.rx_cfg = cl->rx_cfg;
180 ssip.platform_data = NULL;
181 ssip.archdata = NULL;
182
183 modem->ssi_protocol = hsi_new_client(port, &ssip);
184 if (!modem->ssi_protocol) {
185 dev_err(dev, "Could not register ssi-protocol device\n");
186 err = -ENOMEM;
187 goto error2;
188 }
189
190 err = device_attach(&modem->ssi_protocol->device);
191 if (err == 0) {
192 dev_dbg(dev, "Missing ssi-protocol driver\n");
193 err = -EPROBE_DEFER;
194 goto error3;
195 } else if (err < 0) {
196 dev_err(dev, "Could not load ssi-protocol driver (%d)\n", err);
197 goto error3;
198 }
199
200 cmtspeech.name = "cmt-speech";
201 cmtspeech.tx_cfg = cl->tx_cfg;
202 cmtspeech.rx_cfg = cl->rx_cfg;
203 cmtspeech.platform_data = NULL;
204 cmtspeech.archdata = NULL;
205
206 modem->cmt_speech = hsi_new_client(port, &cmtspeech);
207 if (!modem->cmt_speech) {
208 dev_err(dev, "Could not register cmt-speech device\n");
209 err = -ENOMEM;
210 goto error3;
211 }
212
213 err = device_attach(&modem->cmt_speech->device);
214 if (err == 0) {
215 dev_dbg(dev, "Missing cmt-speech driver\n");
216 err = -EPROBE_DEFER;
217 goto error4;
218 } else if (err < 0) {
219 dev_err(dev, "Could not load cmt-speech driver (%d)\n", err);
220 goto error4;
221 }
222
223 dev_info(dev, "Registered Nokia HSI modem\n");
224
225 return 0;
226
227 error4:
228 hsi_remove_client(&modem->cmt_speech->device, NULL);
229 error3:
230 hsi_remove_client(&modem->ssi_protocol->device, NULL);
231 error2:
232 nokia_modem_gpio_unexport(dev);
233 error1:
234 disable_irq_wake(modem->nokia_modem_rst_ind_irq);
235 tasklet_kill(&modem->nokia_modem_rst_ind_tasklet);
236
237 return err;
238 }
239
nokia_modem_remove(struct device * dev)240 static int nokia_modem_remove(struct device *dev)
241 {
242 struct nokia_modem_device *modem = dev_get_drvdata(dev);
243
244 if (!modem)
245 return 0;
246
247 if (modem->cmt_speech) {
248 hsi_remove_client(&modem->cmt_speech->device, NULL);
249 modem->cmt_speech = NULL;
250 }
251
252 if (modem->ssi_protocol) {
253 hsi_remove_client(&modem->ssi_protocol->device, NULL);
254 modem->ssi_protocol = NULL;
255 }
256
257 nokia_modem_gpio_unexport(dev);
258 dev_set_drvdata(dev, NULL);
259 disable_irq_wake(modem->nokia_modem_rst_ind_irq);
260 tasklet_kill(&modem->nokia_modem_rst_ind_tasklet);
261
262 return 0;
263 }
264
265 #ifdef CONFIG_OF
266 static const struct of_device_id nokia_modem_of_match[] = {
267 { .compatible = "nokia,n900-modem", },
268 { .compatible = "nokia,n950-modem", },
269 { .compatible = "nokia,n9-modem", },
270 {},
271 };
272 MODULE_DEVICE_TABLE(of, nokia_modem_of_match);
273 #endif
274
275 static struct hsi_client_driver nokia_modem_driver = {
276 .driver = {
277 .name = "nokia-modem",
278 .owner = THIS_MODULE,
279 .probe = nokia_modem_probe,
280 .remove = nokia_modem_remove,
281 .of_match_table = of_match_ptr(nokia_modem_of_match),
282 },
283 };
284
nokia_modem_init(void)285 static int __init nokia_modem_init(void)
286 {
287 return hsi_register_client_driver(&nokia_modem_driver);
288 }
289 module_init(nokia_modem_init);
290
nokia_modem_exit(void)291 static void __exit nokia_modem_exit(void)
292 {
293 hsi_unregister_client_driver(&nokia_modem_driver);
294 }
295 module_exit(nokia_modem_exit);
296
297 MODULE_ALIAS("hsi:nokia-modem");
298 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
299 MODULE_DESCRIPTION("HSI driver module for Nokia N900 Modem");
300 MODULE_LICENSE("GPL");
301