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; 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 }; 50 51 static void do_nokia_modem_rst_ind_tasklet(unsigned long data) 52 { 53 struct nokia_modem_device *modem = (struct nokia_modem_device *)data; 54 55 if (!modem) 56 return; 57 58 dev_info(modem->device, "CMT rst line change detected\n"); 59 60 if (modem->ssi_protocol) 61 ssip_reset_event(modem->ssi_protocol); 62 } 63 64 static irqreturn_t nokia_modem_rst_ind_isr(int irq, void *data) 65 { 66 struct nokia_modem_device *modem = (struct nokia_modem_device *)data; 67 68 tasklet_schedule(&modem->nokia_modem_rst_ind_tasklet); 69 70 return IRQ_HANDLED; 71 } 72 73 static void nokia_modem_gpio_unexport(struct device *dev) 74 { 75 struct nokia_modem_device *modem = dev_get_drvdata(dev); 76 int i; 77 78 for (i = 0; i < modem->gpio_amount; i++) { 79 sysfs_remove_link(&dev->kobj, modem->gpios[i].name); 80 gpiod_unexport(modem->gpios[i].gpio); 81 } 82 } 83 84 static int nokia_modem_gpio_probe(struct device *dev) 85 { 86 struct device_node *np = dev->of_node; 87 struct nokia_modem_device *modem = dev_get_drvdata(dev); 88 int gpio_count, gpio_name_count, i, err; 89 90 gpio_count = of_gpio_count(np); 91 92 if (gpio_count < 0) { 93 dev_err(dev, "missing gpios: %d\n", gpio_count); 94 return gpio_count; 95 } 96 97 gpio_name_count = of_property_count_strings(np, "gpio-names"); 98 99 if (gpio_count != gpio_name_count) { 100 dev_err(dev, "number of gpios does not equal number of gpio names\n"); 101 return -EINVAL; 102 } 103 104 modem->gpios = devm_kzalloc(dev, gpio_count * 105 sizeof(struct nokia_modem_gpio), GFP_KERNEL); 106 if (!modem->gpios) { 107 dev_err(dev, "Could not allocate memory for gpios\n"); 108 return -ENOMEM; 109 } 110 111 modem->gpio_amount = gpio_count; 112 113 for (i = 0; i < gpio_count; i++) { 114 modem->gpios[i].gpio = devm_gpiod_get_index(dev, NULL, i); 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_direction_output(modem->gpios[i].gpio, 0); 128 if (err) 129 return err; 130 131 err = gpiod_export(modem->gpios[i].gpio, 0); 132 if (err) 133 return err; 134 135 err = gpiod_export_link(dev, modem->gpios[i].name, 136 modem->gpios[i].gpio); 137 if (err) 138 return err; 139 } 140 141 return 0; 142 } 143 144 static int nokia_modem_probe(struct device *dev) 145 { 146 struct device_node *np; 147 struct nokia_modem_device *modem; 148 struct hsi_client *cl = to_hsi_client(dev); 149 struct hsi_port *port = hsi_get_port(cl); 150 int irq, pflags, err; 151 struct hsi_board_info ssip; 152 153 np = dev->of_node; 154 if (!np) { 155 dev_err(dev, "device tree node not found\n"); 156 return -ENXIO; 157 } 158 159 modem = devm_kzalloc(dev, sizeof(*modem), GFP_KERNEL); 160 if (!modem) { 161 dev_err(dev, "Could not allocate memory for nokia_modem_device\n"); 162 return -ENOMEM; 163 } 164 dev_set_drvdata(dev, modem); 165 166 irq = irq_of_parse_and_map(np, 0); 167 if (irq < 0) { 168 dev_err(dev, "Invalid rst_ind interrupt (%d)\n", irq); 169 return irq; 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 IRQF_DISABLED | 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 goto error2; 203 } 204 205 err = device_attach(&modem->ssi_protocol->device); 206 if (err == 0) { 207 dev_err(dev, "Missing ssi-protocol driver\n"); 208 err = -EPROBE_DEFER; 209 goto error3; 210 } else if (err < 0) { 211 dev_err(dev, "Could not load ssi-protocol driver (%d)\n", err); 212 goto error3; 213 } 214 215 /* TODO: register cmt-speech hsi client */ 216 217 dev_info(dev, "Registered Nokia HSI modem\n"); 218 219 return 0; 220 221 error3: 222 hsi_remove_client(&modem->ssi_protocol->device, NULL); 223 error2: 224 nokia_modem_gpio_unexport(dev); 225 error1: 226 disable_irq_wake(modem->nokia_modem_rst_ind_irq); 227 tasklet_kill(&modem->nokia_modem_rst_ind_tasklet); 228 229 return err; 230 } 231 232 static int nokia_modem_remove(struct device *dev) 233 { 234 struct nokia_modem_device *modem = dev_get_drvdata(dev); 235 236 if (!modem) 237 return 0; 238 239 if (modem->ssi_protocol) { 240 hsi_remove_client(&modem->ssi_protocol->device, NULL); 241 modem->ssi_protocol = NULL; 242 } 243 244 nokia_modem_gpio_unexport(dev); 245 dev_set_drvdata(dev, NULL); 246 disable_irq_wake(modem->nokia_modem_rst_ind_irq); 247 tasklet_kill(&modem->nokia_modem_rst_ind_tasklet); 248 249 return 0; 250 } 251 252 #ifdef CONFIG_OF 253 static const struct of_device_id nokia_modem_of_match[] = { 254 { .compatible = "nokia,n900-modem", }, 255 {}, 256 }; 257 MODULE_DEVICE_TABLE(of, nokia_modem_of_match); 258 #endif 259 260 static struct hsi_client_driver nokia_modem_driver = { 261 .driver = { 262 .name = "nokia-modem", 263 .owner = THIS_MODULE, 264 .probe = nokia_modem_probe, 265 .remove = nokia_modem_remove, 266 .of_match_table = of_match_ptr(nokia_modem_of_match), 267 }, 268 }; 269 270 static int __init nokia_modem_init(void) 271 { 272 return hsi_register_client_driver(&nokia_modem_driver); 273 } 274 module_init(nokia_modem_init); 275 276 static void __exit nokia_modem_exit(void) 277 { 278 hsi_unregister_client_driver(&nokia_modem_driver); 279 } 280 module_exit(nokia_modem_exit); 281 282 MODULE_ALIAS("hsi:nokia-modem"); 283 MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>"); 284 MODULE_DESCRIPTION("HSI driver module for Nokia N900 Modem"); 285 MODULE_LICENSE("GPL"); 286