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 };
  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) {
 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                 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");