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 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 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 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 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 } 141 142 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 } 255 256 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 }; 300 301 static int __init nokia_modem_init(void) 302 { 303 return hsi_register_client_driver(&nokia_modem_driver); 304 } 305 module_init(nokia_modem_init); 306 307 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