drivers/spi/tsc2101.c

   1 /*
   2  * linux/drivers/spi/tsc2101.c
   3  *
   4  * TSC2101 codec interface driver for the OMAP platform
   5  *
   6  * Copyright (C) 2004 Texas Instruments, Inc.
   7  *
   8  * This package is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  13  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  14  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  15  *
  16  * History:
  17  *
  18  * 2004/11/07   Nishanth Menon - Modified for common hooks for Audio and Touchscreen
  19  */
  20
  21 #include <linux/kernel.h>
  22 #include <linux/clk.h>
  23 #include <linux/device.h>
  24 #include <linux/spi/spi.h>
  25 #include <linux/spi/tsc2101.h>
  26
  27 struct tsc2101_device {
  28         struct mutex            mutex;
  29         int                     mclk_enabled;
  30         struct clock            *mclk_ck;
  31         struct spi_message      message;
  32         struct spi_transfer     transfer[2];
  33         u16                     command;
  34         void                    (*enable_mclk)(struct spi_device *spi);
  35         void                    (*disable_mclk)(struct spi_device *spi);
  36 };
  37
  38 int tsc2101_enable_mclk(struct spi_device *spi)
  39 {
  40         struct tsc2101_device *tsc2101;
  41
  42         tsc2101 = spi_get_drvdata(spi);
  43
  44         mutex_lock(&tsc2101->mutex);
  45
  46         if (spi->dev.power.power_state.event != PM_EVENT_ON) {
  47                 mutex_unlock(&tsc2101->mutex);
  48                 return -ENODEV;
  49         }
  50
  51         if (tsc2101->mclk_enabled++ == 0) {
  52                 if (tsc2101->enable_mclk != NULL)
  53                         tsc2101->enable_mclk(spi);
  54         }
  55
  56         mutex_unlock(&tsc2101->mutex);
  57         return 0;
  58 }
  59 EXPORT_SYMBOL(tsc2101_enable_mclk);
  60
  61 void tsc2101_disable_mclk(struct spi_device *spi)
  62 {
  63         struct tsc2101_device *tsc2101;
  64
  65         tsc2101 = spi_get_drvdata(spi);
  66
  67         mutex_lock(&tsc2101->mutex);
  68
  69         if (--tsc2101->mclk_enabled == 0) {
  70                 if (tsc2101->disable_mclk != NULL &&
  71                     spi->dev.power.power_state.event == PM_EVENT_ON)
  72                         tsc2101->disable_mclk(spi);
  73         }
  74
  75         mutex_lock(&tsc2101->mutex);
  76 }
  77 EXPORT_SYMBOL(tsc2101_disable_mclk);
  78
  79 int tsc2101_write_sync(struct spi_device *spi, int page, u8 address, u16 data)
  80 {
  81         struct tsc2101_device *tsc2101;
  82         struct spi_message *m;
  83         struct spi_transfer *t;
  84         int ret;
  85
  86         tsc2101 = spi_get_drvdata(spi);
  87
  88         mutex_lock(&tsc2101->mutex);
  89         if (spi->dev.power.power_state.event != PM_EVENT_ON) {
  90                 mutex_unlock(&tsc2101->mutex);
  91                 return -ENODEV;
  92         }
  93
  94         m = &tsc2101->message;
  95         spi_message_init(m);
  96         t = &tsc2101->transfer[0];
  97         memset(t, 0, sizeof(tsc2101->transfer));
  98
  99         /* Address */
 100         tsc2101->command = (page << 11) | (address << 5);
 101         t->tx_buf = &tsc2101->command;
 102         t->len = 2;
 103         spi_message_add_tail(t, m);
 104
 105         /* Data */
 106         t++;
 107         t->tx_buf = &data;
 108         t->len = 2;
 109         spi_message_add_tail(t, m);
 110
 111         ret = spi_sync(spi, m);
 112         if (!ret)
 113                 ret = tsc2101->message.status;
 114         mutex_unlock(&tsc2101->mutex);
 115
 116         return ret;
 117 }
 118 EXPORT_SYMBOL(tsc2101_write_sync);
 119
 120 int tsc2101_reads_sync(struct spi_device *spi,
 121                        int page, u8 startaddress, u16 *data, int numregs)
 122 {
 123         struct tsc2101_device *tsc2101;
 124         struct spi_message *m;
 125         struct spi_transfer *t;
 126         int ret;
 127
 128         tsc2101 = spi_get_drvdata(spi);
 129
 130         mutex_lock(&tsc2101->mutex);
 131         if (spi->dev.power.power_state.event != PM_EVENT_ON) {
 132                 mutex_unlock(&tsc2101->mutex);
 133                 return -ENODEV;
 134         }
 135
 136         m = &tsc2101->message;
 137         spi_message_init(m);
 138         t = &tsc2101->transfer[0];
 139         memset(t, 0, sizeof(tsc2101->transfer));
 140
 141         /* Address */
 142         tsc2101->command = 0x8000 | (page << 11) | (startaddress << 5);
 143         t->tx_buf = &tsc2101->command;
 144         t->len = 2;
 145         spi_message_add_tail(t, m);
 146
 147         /* Data */
 148         t++;
 149         t->rx_buf = data;
 150         t->len = numregs << 1;
 151         spi_message_add_tail(t, m);
 152
 153         ret = spi_sync(spi, m);
 154         if (!ret)
 155                 ret = tsc2101->message.status;
 156
 157         mutex_unlock(&tsc2101->mutex);
 158
 159         return ret;
 160 }
 161 EXPORT_SYMBOL(tsc2101_reads_sync);
 162
 163 int tsc2101_read_sync(struct spi_device *spi, int page, u8 address)
 164 {
 165         int err;
 166         u16 val;
 167
 168         err = tsc2101_reads_sync(spi, page, address, &val, 1);
 169         if (err)
 170                 return err;
 171         return val;
 172 }
 173 EXPORT_SYMBOL(tsc2101_read_sync);
 174
 175 static int tsc2101_suspend(struct spi_device *spi, pm_message_t state)
 176 {
 177         struct tsc2101_device *tsc2101;
 178
 179         tsc2101 = spi_get_drvdata(spi);
 180
 181         if (tsc2101 == NULL)
 182                 return 0;
 183
 184         mutex_lock(&tsc2101->mutex);
 185
 186         spi->dev.power.power_state = state;
 187         if (tsc2101->mclk_enabled && tsc2101->disable_mclk != NULL)
 188                 tsc2101->disable_mclk(spi);
 189
 190         mutex_unlock(&tsc2101->mutex);
 191
 192         return 0;
 193 }
 194
 195 static int tsc2101_resume(struct spi_device *spi)
 196 {
 197         struct tsc2101_device *tsc2101;
 198
 199         tsc2101 = spi_get_drvdata(spi);
 200
 201         if (tsc2101 == NULL)
 202                 return 0;
 203
 204         mutex_lock(&tsc2101->mutex);
 205
 206         spi->dev.power.power_state = PMSG_ON;
 207         if (tsc2101->mclk_enabled && tsc2101->enable_mclk != NULL)
 208                 tsc2101->enable_mclk(spi);
 209
 210         mutex_unlock(&tsc2101->mutex);
 211
 212         return 0;
 213 }
 214
 215 static int tsc2101_probe(struct spi_device *spi)
 216 {
 217         struct tsc2101_platform_data *pdata;
 218         struct tsc2101_device *tsc2101;
 219         u16 w;
 220         int r;
 221
 222         pdata = spi->dev.platform_data;
 223         if (pdata == NULL) {
 224                 dev_err(&spi->dev, "no platform data\n");
 225                 return -ENODEV;
 226         }
 227
 228         tsc2101 = kzalloc(sizeof(*tsc2101), GFP_KERNEL);
 229         if (tsc2101 == NULL) {
 230                 dev_err(&spi->dev, "out of mem\n");
 231                 return -ENOMEM;
 232         }
 233
 234         spi_set_drvdata(spi, tsc2101);
 235         tsc2101->enable_mclk = pdata->enable_mclk;
 236         tsc2101->disable_mclk = pdata->disable_mclk;
 237
 238         mutex_init(&tsc2101->mutex);
 239
 240         spi->mode = SPI_MODE_0;
 241         spi->bits_per_word = 16;
 242         if ((r = spi_setup(spi)) < 0) {
 243                 dev_err(&spi->dev, "SPI setup failed\n");
 244                 goto err;
 245         }
 246
 247         w = tsc2101_read_sync(spi, 1, 0);
 248         if (!(w & (1 << 14))) {
 249                 dev_err(&spi->dev, "invalid ADC register value %04x\n", w);
 250                 goto err;
 251         }
 252
 253         if (pdata->init != NULL) {
 254                 if ((r = pdata->init(spi)) < 0) {
 255                         dev_err(&spi->dev, "platform init failed\n");
 256                         goto err;
 257                 }
 258         }
 259
 260         dev_info(&spi->dev, "initialized\n");
 261
 262         return 0;
 263 err:
 264         kfree(tsc2101);
 265         return r;
 266 }
 267
 268 static int tsc2101_remove(struct spi_device *spi)
 269 {
 270         struct tsc2101_platform_data *pdata;
 271         struct tsc2101_device *tsc2101;
 272
 273         pdata = spi->dev.platform_data;
 274         tsc2101 = spi_get_drvdata(spi);
 275
 276         /* We assume that this can't race with the rest of the driver. */
 277         if (tsc2101->mclk_enabled && tsc2101->disable_mclk != NULL)
 278                 tsc2101->disable_mclk(spi);
 279
 280         if (pdata->cleanup != NULL)
 281                 pdata->cleanup(spi);
 282
 283         spi_set_drvdata(spi, NULL);
 284         kfree(tsc2101);
 285
 286         return 0;
 287 }
 288
 289 static struct spi_driver tsc2101_driver = {
 290         .probe          = tsc2101_probe,
 291         .remove         = tsc2101_remove,
 292         .suspend        = tsc2101_suspend,
 293         .resume         = tsc2101_resume,
 294         .driver         = {
 295                 .name   = "tsc2101",
 296                 .owner  = THIS_MODULE,
 297         },
 298 };
 299
 300 static int tsc2101_init(void)
 301 {
 302         return spi_register_driver(&tsc2101_driver);
 303 }
 304
 305 static void tsc2101_exit(void)
 306 {
 307         spi_unregister_driver(&tsc2101_driver);
 308 }
 309
 310 module_init(tsc2101_init);
 311 module_exit(tsc2101_exit);
 312
 313 MODULE_AUTHOR("Texas Instruments");
 314 MODULE_DESCRIPTION
 315     ("Glue audio driver for the TI OMAP1610/OMAP1710 TSC2101 codec.");
 316 MODULE_LICENSE("GPL");