drivers/hsi/clients/nokia-modem.c

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