1 /*
2 * nokia-modem.c
3 *
4 * HSI client driver for Nokia N900 modem.
5 *
6 * Copyright (C) 2014 Sebastian Reichel <sre@kernel.org>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * version 2 as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20 * 02110-1301 USA
21 */
22
23 #include <linux/gpio/consumer.h>
24 #include <linux/hsi/hsi.h>
25 #include <linux/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/of.h>
28 #include <linux/of_irq.h>
29 #include <linux/of_gpio.h>
30 #include <linux/hsi/ssi_protocol.h>
31
32 static unsigned int pm = 1;
33 module_param(pm, int, 0400);
34 MODULE_PARM_DESC(pm,
35 "Enable power management (0=disabled, 1=userland based [default])");
36
37 struct nokia_modem_gpio {
38 struct gpio_desc *gpio;
39 const char *name;
40 };
41
42 struct nokia_modem_device {
43 struct tasklet_struct nokia_modem_rst_ind_tasklet;
44 int nokia_modem_rst_ind_irq;
45 struct device *device;
46 struct nokia_modem_gpio *gpios;
47 int gpio_amount;
48 struct hsi_client *ssi_protocol;
49 struct hsi_client *cmt_speech;
50 };
51
do_nokia_modem_rst_ind_tasklet(unsigned long data)52 static void do_nokia_modem_rst_ind_tasklet(unsigned long data)
53 {
54 struct nokia_modem_device *modem = (struct nokia_modem_device *)data;
55
56 if (!modem)
57 return;
58
59 dev_info(modem->device, "CMT rst line change detected\n");
60
61 if (modem->ssi_protocol)
62 ssip_reset_event(modem->ssi_protocol);
63 }
64
nokia_modem_rst_ind_isr(int irq,void * data)65 static irqreturn_t nokia_modem_rst_ind_isr(int irq, void *data)
66 {
67 struct nokia_modem_device *modem = (struct nokia_modem_device *)data;
68
69 tasklet_schedule(&modem->nokia_modem_rst_ind_tasklet);
70
71 return IRQ_HANDLED;
72 }
73
nokia_modem_gpio_unexport(struct device * dev)74 static void nokia_modem_gpio_unexport(struct device *dev)
75 {
76 struct nokia_modem_device *modem = dev_get_drvdata(dev);
77 int i;
78
79 for (i = 0; i < modem->gpio_amount; i++) {
80 sysfs_remove_link(&dev->kobj, modem->gpios[i].name);
81 gpiod_unexport(modem->gpios[i].gpio);
82 }
83 }
84
nokia_modem_gpio_probe(struct device * dev)85 static int nokia_modem_gpio_probe(struct device *dev)
86 {
87 struct device_node *np = dev->of_node;
88 struct nokia_modem_device *modem = dev_get_drvdata(dev);
89 int gpio_count, gpio_name_count, i, err;
90
91 gpio_count = of_gpio_count(np);
92
93 if (gpio_count < 0) {
94 dev_err(dev, "missing gpios: %d\n", gpio_count);
95 return gpio_count;
96 }
97
98 gpio_name_count = of_property_count_strings(np, "gpio-names");
99
100 if (gpio_count != gpio_name_count) {
101 dev_err(dev, "number of gpios does not equal number of gpio names\n");
102 return -EINVAL;
103 }
104
105 modem->gpios = devm_kzalloc(dev, gpio_count *
106 sizeof(struct nokia_modem_gpio), GFP_KERNEL);
107 if (!modem->gpios) {
108 dev_err(dev, "Could not allocate memory for gpios\n");
109 return -ENOMEM;
110 }
111
112 modem->gpio_amount = gpio_count;
113
114 for (i = 0; i < gpio_count; i++) {
115 modem->gpios[i].gpio = devm_gpiod_get_index(dev, NULL, i,
116 GPIOD_OUT_LOW);
117 if (IS_ERR(modem->gpios[i].gpio)) {
118 dev_err(dev, "Could not get gpio %d\n", i);
119 return PTR_ERR(modem->gpios[i].gpio);
120 }
121
122 err = of_property_read_string_index(np, "gpio-names", i,
123 &(modem->gpios[i].name));
124 if (err) {
125 dev_err(dev, "Could not get gpio name %d\n", i);
126 return err;
127 }
128
129 err = gpiod_export(modem->gpios[i].gpio, 0);
130 if (err)
131 return err;
132
133 err = gpiod_export_link(dev, modem->gpios[i].name,
134 modem->gpios[i].gpio);
135 if (err)
136 return err;
137 }
138
139 return 0;
140 }
141
nokia_modem_probe(struct device * dev)142 static int nokia_modem_probe(struct device *dev)
143 {
144 struct device_node *np;
145 struct nokia_modem_device *modem;
146 struct hsi_client *cl = to_hsi_client(dev);
147 struct hsi_port *port = hsi_get_port(cl);
148 int irq, pflags, err;
149 struct hsi_board_info ssip;
150 struct hsi_board_info cmtspeech;
151
152 np = dev->of_node;
153 if (!np) {
154 dev_err(dev, "device tree node not found\n");
155 return -ENXIO;
156 }
157
158 modem = devm_kzalloc(dev, sizeof(*modem), GFP_KERNEL);
159 if (!modem) {
160 dev_err(dev, "Could not allocate memory for nokia_modem_device\n");
161 return -ENOMEM;
162 }
163 dev_set_drvdata(dev, modem);
164 modem->device = dev;
165
166 irq = irq_of_parse_and_map(np, 0);
167 if (!irq) {
168 dev_err(dev, "Invalid rst_ind interrupt (%d)\n", irq);
169 return -EINVAL;
170 }
171 modem->nokia_modem_rst_ind_irq = irq;
172 pflags = irq_get_trigger_type(irq);
173
174 tasklet_init(&modem->nokia_modem_rst_ind_tasklet,
175 do_nokia_modem_rst_ind_tasklet, (unsigned long)modem);
176 err = devm_request_irq(dev, irq, nokia_modem_rst_ind_isr,
177 pflags, "modem_rst_ind", modem);
178 if (err < 0) {
179 dev_err(dev, "Request rst_ind irq(%d) failed (flags %d)\n",
180 irq, pflags);
181 return err;
182 }
183 enable_irq_wake(irq);
184
185 if(pm) {
186 err = nokia_modem_gpio_probe(dev);
187 if (err < 0) {
188 dev_err(dev, "Could not probe GPIOs\n");
189 goto error1;
190 }
191 }
192
193 ssip.name = "ssi-protocol";
194 ssip.tx_cfg = cl->tx_cfg;
195 ssip.rx_cfg = cl->rx_cfg;
196 ssip.platform_data = NULL;
197 ssip.archdata = NULL;
198
199 modem->ssi_protocol = hsi_new_client(port, &ssip);
200 if (!modem->ssi_protocol) {
201 dev_err(dev, "Could not register ssi-protocol device\n");
202 err = -ENOMEM;
203 goto error2;
204 }
205
206 err = device_attach(&modem->ssi_protocol->device);
207 if (err == 0) {
208 dev_dbg(dev, "Missing ssi-protocol driver\n");
209 err = -EPROBE_DEFER;
210 goto error3;
211 } else if (err < 0) {
212 dev_err(dev, "Could not load ssi-protocol driver (%d)\n", err);
213 goto error3;
214 }
215
216 cmtspeech.name = "cmt-speech";
217 cmtspeech.tx_cfg = cl->tx_cfg;
218 cmtspeech.rx_cfg = cl->rx_cfg;
219 cmtspeech.platform_data = NULL;
220 cmtspeech.archdata = NULL;
221
222 modem->cmt_speech = hsi_new_client(port, &cmtspeech);
223 if (!modem->cmt_speech) {
224 dev_err(dev, "Could not register cmt-speech device\n");
225 err = -ENOMEM;
226 goto error3;
227 }
228
229 err = device_attach(&modem->cmt_speech->device);
230 if (err == 0) {
231 dev_dbg(dev, "Missing cmt-speech driver\n");
232 err = -EPROBE_DEFER;
233 goto error4;
234 } else if (err < 0) {
235 dev_err(dev, "Could not load cmt-speech driver (%d)\n", err);
236 goto error4;
237 }
238
239 dev_info(dev, "Registered Nokia HSI modem\n");
240
241 return 0;
242
243 error4:
244 hsi_remove_client(&modem->cmt_speech->device, NULL);
245 error3:
246 hsi_remove_client(&modem->ssi_protocol->device, NULL);
247 error2:
248 nokia_modem_gpio_unexport(dev);
249 error1:
250 disable_irq_wake(modem->nokia_modem_rst_ind_irq);
251 tasklet_kill(&modem->nokia_modem_rst_ind_tasklet);
252
253 return err;
254 }
255
nokia_modem_remove(struct device * dev)256 static int nokia_modem_remove(struct device *dev)
257 {
258 struct nokia_modem_device *modem = dev_get_drvdata(dev);
259
260 if (!modem)
261 return 0;
262
263 if (modem->cmt_speech) {
264 hsi_remove_client(&modem->cmt_speech->device, NULL);
265 modem->cmt_speech = NULL;
266 }
267
268 if (modem->ssi_protocol) {
269 hsi_remove_client(&modem->ssi_protocol->device, NULL);
270 modem->ssi_protocol = NULL;
271 }
272
273 nokia_modem_gpio_unexport(dev);
274 dev_set_drvdata(dev, NULL);
275 disable_irq_wake(modem->nokia_modem_rst_ind_irq);
276 tasklet_kill(&modem->nokia_modem_rst_ind_tasklet);
277
278 return 0;
279 }
280
281 #ifdef CONFIG_OF
282 static const struct of_device_id nokia_modem_of_match[] = {
283 { .compatible = "nokia,n900-modem", },
284 { .compatible = "nokia,n950-modem", },
285 { .compatible = "nokia,n9-modem", },
286 {},
287 };
288 MODULE_DEVICE_TABLE(of, nokia_modem_of_match);
289 #endif
290
291 static struct hsi_client_driver nokia_modem_driver = {
292 .driver = {
293 .name = "nokia-modem",
294 .owner = THIS_MODULE,
295 .probe = nokia_modem_probe,
296 .remove = nokia_modem_remove,
297 .of_match_table = of_match_ptr(nokia_modem_of_match),
298 },
299 };
300
nokia_modem_init(void)301 static int __init nokia_modem_init(void)
302 {
303 return hsi_register_client_driver(&nokia_modem_driver);
304 }
305 module_init(nokia_modem_init);
306
nokia_modem_exit(void)307 static void __exit nokia_modem_exit(void)
308 {
309 hsi_unregister_client_driver(&nokia_modem_driver);
310 }
311 module_exit(nokia_modem_exit);
312
313 MODULE_ALIAS("hsi:nokia-modem");
314 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
315 MODULE_DESCRIPTION("HSI driver module for Nokia N900 Modem");
316 MODULE_LICENSE("GPL");
317