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_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");