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_kcalloc(dev, gpio_count, sizeof(*modem->gpios), 106 GFP_KERNEL); 107 if (!modem->gpios) 108 return -ENOMEM; 109 110 modem->gpio_amount = gpio_count; 111 112 for (i = 0; i < gpio_count; i++) { 113 modem->gpios[i].gpio = devm_gpiod_get_index(dev, NULL, i, 114 GPIOD_OUT_LOW); 115 if (IS_ERR(modem->gpios[i].gpio)) { 116 dev_err(dev, "Could not get gpio %d\n", i); 117 return PTR_ERR(modem->gpios[i].gpio); 118 } 119 120 err = of_property_read_string_index(np, "gpio-names", i, 121 &(modem->gpios[i].name)); 122 if (err) { 123 dev_err(dev, "Could not get gpio name %d\n", i); 124 return err; 125 } 126 127 err = gpiod_export(modem->gpios[i].gpio, 0); 128 if (err) 129 return err; 130 131 err = gpiod_export_link(dev, modem->gpios[i].name, 132 modem->gpios[i].gpio); 133 if (err) 134 return err; 135 } 136 137 return 0; 138 } 139 140 static int nokia_modem_probe(struct device *dev) 141 { 142 struct device_node *np; 143 struct nokia_modem_device *modem; 144 struct hsi_client *cl = to_hsi_client(dev); 145 struct hsi_port *port = hsi_get_port(cl); 146 int irq, pflags, err; 147 struct hsi_board_info ssip; 148 struct hsi_board_info cmtspeech; 149 150 np = dev->of_node; 151 if (!np) { 152 dev_err(dev, "device tree node not found\n"); 153 return -ENXIO; 154 } 155 156 modem = devm_kzalloc(dev, sizeof(*modem), GFP_KERNEL); 157 if (!modem) 158 return -ENOMEM; 159 160 dev_set_drvdata(dev, modem); 161 modem->device = dev; 162 163 irq = irq_of_parse_and_map(np, 0); 164 if (!irq) { 165 dev_err(dev, "Invalid rst_ind interrupt (%d)\n", irq); 166 return -EINVAL; 167 } 168 modem->nokia_modem_rst_ind_irq = irq; 169 pflags = irq_get_trigger_type(irq); 170 171 tasklet_init(&modem->nokia_modem_rst_ind_tasklet, 172 do_nokia_modem_rst_ind_tasklet, (unsigned long)modem); 173 err = devm_request_irq(dev, irq, nokia_modem_rst_ind_isr, 174 pflags, "modem_rst_ind", modem); 175 if (err < 0) { 176 dev_err(dev, "Request rst_ind irq(%d) failed (flags %d)\n", 177 irq, pflags); 178 return err; 179 } 180 enable_irq_wake(irq); 181 182 if (pm) { 183 err = nokia_modem_gpio_probe(dev); 184 if (err < 0) { 185 dev_err(dev, "Could not probe GPIOs\n"); 186 goto error1; 187 } 188 } 189 190 ssip.name = "ssi-protocol"; 191 ssip.tx_cfg = cl->tx_cfg; 192 ssip.rx_cfg = cl->rx_cfg; 193 ssip.platform_data = NULL; 194 ssip.archdata = NULL; 195 196 modem->ssi_protocol = hsi_new_client(port, &ssip); 197 if (!modem->ssi_protocol) { 198 dev_err(dev, "Could not register ssi-protocol device\n"); 199 err = -ENOMEM; 200 goto error2; 201 } 202 203 err = device_attach(&modem->ssi_protocol->device); 204 if (err == 0) { 205 dev_dbg(dev, "Missing ssi-protocol driver\n"); 206 err = -EPROBE_DEFER; 207 goto error3; 208 } else if (err < 0) { 209 dev_err(dev, "Could not load ssi-protocol driver (%d)\n", err); 210 goto error3; 211 } 212 213 cmtspeech.name = "cmt-speech"; 214 cmtspeech.tx_cfg = cl->tx_cfg; 215 cmtspeech.rx_cfg = cl->rx_cfg; 216 cmtspeech.platform_data = NULL; 217 cmtspeech.archdata = NULL; 218 219 modem->cmt_speech = hsi_new_client(port, &cmtspeech); 220 if (!modem->cmt_speech) { 221 dev_err(dev, "Could not register cmt-speech device\n"); 222 err = -ENOMEM; 223 goto error3; 224 } 225 226 err = device_attach(&modem->cmt_speech->device); 227 if (err == 0) { 228 dev_dbg(dev, "Missing cmt-speech driver\n"); 229 err = -EPROBE_DEFER; 230 goto error4; 231 } else if (err < 0) { 232 dev_err(dev, "Could not load cmt-speech driver (%d)\n", err); 233 goto error4; 234 } 235 236 dev_info(dev, "Registered Nokia HSI modem\n"); 237 238 return 0; 239 240 error4: 241 hsi_remove_client(&modem->cmt_speech->device, NULL); 242 error3: 243 hsi_remove_client(&modem->ssi_protocol->device, NULL); 244 error2: 245 nokia_modem_gpio_unexport(dev); 246 error1: 247 disable_irq_wake(modem->nokia_modem_rst_ind_irq); 248 tasklet_kill(&modem->nokia_modem_rst_ind_tasklet); 249 250 return err; 251 } 252 253 static int nokia_modem_remove(struct device *dev) 254 { 255 struct nokia_modem_device *modem = dev_get_drvdata(dev); 256 257 if (!modem) 258 return 0; 259 260 if (modem->cmt_speech) { 261 hsi_remove_client(&modem->cmt_speech->device, NULL); 262 modem->cmt_speech = NULL; 263 } 264 265 if (modem->ssi_protocol) { 266 hsi_remove_client(&modem->ssi_protocol->device, NULL); 267 modem->ssi_protocol = NULL; 268 } 269 270 nokia_modem_gpio_unexport(dev); 271 dev_set_drvdata(dev, NULL); 272 disable_irq_wake(modem->nokia_modem_rst_ind_irq); 273 tasklet_kill(&modem->nokia_modem_rst_ind_tasklet); 274 275 return 0; 276 } 277 278 #ifdef CONFIG_OF 279 static const struct of_device_id nokia_modem_of_match[] = { 280 { .compatible = "nokia,n900-modem", }, 281 { .compatible = "nokia,n950-modem", }, 282 { .compatible = "nokia,n9-modem", }, 283 {}, 284 }; 285 MODULE_DEVICE_TABLE(of, nokia_modem_of_match); 286 #endif 287 288 static struct hsi_client_driver nokia_modem_driver = { 289 .driver = { 290 .name = "nokia-modem", 291 .owner = THIS_MODULE, 292 .probe = nokia_modem_probe, 293 .remove = nokia_modem_remove, 294 .of_match_table = of_match_ptr(nokia_modem_of_match), 295 }, 296 }; 297 298 static int __init nokia_modem_init(void) 299 { 300 return hsi_register_client_driver(&nokia_modem_driver); 301 } 302 module_init(nokia_modem_init); 303 304 static void __exit nokia_modem_exit(void) 305 { 306 hsi_unregister_client_driver(&nokia_modem_driver); 307 } 308 module_exit(nokia_modem_exit); 309 310 MODULE_ALIAS("hsi:nokia-modem"); 311 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>"); 312 MODULE_DESCRIPTION("HSI driver module for Nokia N900 Modem"); 313 MODULE_LICENSE("GPL"); 314