drivers/tty/serial/max3107-aava.c

   1 /*
   2  *  max3107.c - spi uart protocol driver for Maxim 3107
   3  *  Based on max3100.c
   4  *      by Christian Pellegrin <chripell@evolware.org>
   5  *  and max3110.c
   6  *      by Feng Tang <feng.tang@intel.com>
   7  *
   8  *  Copyright (C) Aavamobile 2009
   9  *
  10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or
  15  *  (at your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License
  23  *  along with this program; if not, write to the Free Software
  24  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25  *
  26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27  *
  28  */
  29
  30 #include <linux/delay.h>
  31 #include <linux/device.h>
  32 #include <linux/serial_core.h>
  33 #include <linux/serial.h>
  34 #include <linux/spi/spi.h>
  35 #include <linux/freezer.h>
  36 #include <linux/platform_device.h>
  37 #include <linux/gpio.h>
  38 #include <linux/sfi.h>
  39 #include <asm/mrst.h>
  40 #include "max3107.h"
  41
  42 /* GPIO direction to input function */
  43 static int max3107_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  44 {
  45         struct max3107_port *s = container_of(chip, struct max3107_port, chip);
  46         u16 buf[1];             /* Buffer for SPI transfer */
  47
  48         if (offset >= MAX3107_GPIO_COUNT) {
  49                 dev_err(&s->spi->dev, "Invalid GPIO\n");
  50                 return -EINVAL;
  51         }
  52
  53         /* Read current GPIO configuration register */
  54         buf[0] = MAX3107_GPIOCFG_REG;
  55         /* Perform SPI transfer */
  56         if (max3107_rw(s, (u8 *)buf, (u8 *)buf, 2)) {
  57                 dev_err(&s->spi->dev, "SPI transfer GPIO read failed\n");
  58                 return -EIO;
  59         }
  60         buf[0] &= MAX3107_SPI_RX_DATA_MASK;
  61
  62         /* Set GPIO to input */
  63         buf[0] &= ~(0x0001 << offset);
  64
  65         /* Write new GPIO configuration register value */
  66         buf[0] |= (MAX3107_WRITE_BIT | MAX3107_GPIOCFG_REG);
  67         /* Perform SPI transfer */
  68         if (max3107_rw(s, (u8 *)buf, NULL, 2)) {
  69                 dev_err(&s->spi->dev, "SPI transfer GPIO write failed\n");
  70                 return -EIO;
  71         }
  72         return 0;
  73 }
  74
  75 /* GPIO direction to output function */
  76 static int max3107_gpio_direction_out(struct gpio_chip *chip, unsigned offset,
  77                                         int value)
  78 {
  79         struct max3107_port *s = container_of(chip, struct max3107_port, chip);
  80         u16 buf[2];     /* Buffer for SPI transfers */
  81
  82         if (offset >= MAX3107_GPIO_COUNT) {
  83                 dev_err(&s->spi->dev, "Invalid GPIO\n");
  84                 return -EINVAL;
  85         }
  86
  87         /* Read current GPIO configuration and data registers */
  88         buf[0] = MAX3107_GPIOCFG_REG;
  89         buf[1] = MAX3107_GPIODATA_REG;
  90         /* Perform SPI transfer */
  91         if (max3107_rw(s, (u8 *)buf, (u8 *)buf, 4)) {
  92                 dev_err(&s->spi->dev, "SPI transfer gpio failed\n");
  93                 return -EIO;
  94         }
  95         buf[0] &= MAX3107_SPI_RX_DATA_MASK;
  96         buf[1] &= MAX3107_SPI_RX_DATA_MASK;
  97
  98         /* Set GPIO to output */
  99         buf[0] |= (0x0001 << offset);
 100         /* Set value */
 101         if (value)
 102                 buf[1] |= (0x0001 << offset);
 103         else
 104                 buf[1] &= ~(0x0001 << offset);
 105
 106         /* Write new GPIO configuration and data register values */
 107         buf[0] |= (MAX3107_WRITE_BIT | MAX3107_GPIOCFG_REG);
 108         buf[1] |= (MAX3107_WRITE_BIT | MAX3107_GPIODATA_REG);
 109         /* Perform SPI transfer */
 110         if (max3107_rw(s, (u8 *)buf, NULL, 4)) {
 111                 dev_err(&s->spi->dev,
 112                         "SPI transfer for GPIO conf data w failed\n");
 113                 return -EIO;
 114         }
 115         return 0;
 116 }
 117
 118 /* GPIO value query function */
 119 static int max3107_gpio_get(struct gpio_chip *chip, unsigned offset)
 120 {
 121         struct max3107_port *s = container_of(chip, struct max3107_port, chip);
 122         u16 buf[1];     /* Buffer for SPI transfer */
 123
 124         if (offset >= MAX3107_GPIO_COUNT) {
 125                 dev_err(&s->spi->dev, "Invalid GPIO\n");
 126                 return -EINVAL;
 127         }
 128
 129         /* Read current GPIO data register */
 130         buf[0] = MAX3107_GPIODATA_REG;
 131         /* Perform SPI transfer */
 132         if (max3107_rw(s, (u8 *)buf, (u8 *)buf, 2)) {
 133                 dev_err(&s->spi->dev, "SPI transfer GPIO data r failed\n");
 134                 return -EIO;
 135         }
 136         buf[0] &= MAX3107_SPI_RX_DATA_MASK;
 137
 138         /* Return value */
 139         return buf[0] & (0x0001 << offset);
 140 }
 141
 142 /* GPIO value set function */
 143 static void max3107_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 144 {
 145         struct max3107_port *s = container_of(chip, struct max3107_port, chip);
 146         u16 buf[2];     /* Buffer for SPI transfers */
 147
 148         if (offset >= MAX3107_GPIO_COUNT) {
 149                 dev_err(&s->spi->dev, "Invalid GPIO\n");
 150                 return;
 151         }
 152
 153         /* Read current GPIO configuration registers*/
 154         buf[0] = MAX3107_GPIODATA_REG;
 155         buf[1] = MAX3107_GPIOCFG_REG;
 156         /* Perform SPI transfer */
 157         if (max3107_rw(s, (u8 *)buf, (u8 *)buf, 4)) {
 158                 dev_err(&s->spi->dev,
 159                         "SPI transfer for GPIO data and config read failed\n");
 160                 return;
 161         }
 162         buf[0] &= MAX3107_SPI_RX_DATA_MASK;
 163         buf[1] &= MAX3107_SPI_RX_DATA_MASK;
 164
 165         if (!(buf[1] & (0x0001 << offset))) {
 166                 /* Configured as input, can't set value */
 167                 dev_warn(&s->spi->dev,
 168                                 "Trying to set value for input GPIO\n");
 169                 return;
 170         }
 171
 172         /* Set value */
 173         if (value)
 174                 buf[0] |= (0x0001 << offset);
 175         else
 176                 buf[0] &= ~(0x0001 << offset);
 177
 178         /* Write new GPIO data register value */
 179         buf[0] |= (MAX3107_WRITE_BIT | MAX3107_GPIODATA_REG);
 180         /* Perform SPI transfer */
 181         if (max3107_rw(s, (u8 *)buf, NULL, 2))
 182                 dev_err(&s->spi->dev, "SPI transfer GPIO data w failed\n");
 183 }
 184
 185 /* GPIO chip data */
 186 static struct gpio_chip max3107_gpio_chip = {
 187         .owner                  = THIS_MODULE,
 188         .direction_input        = max3107_gpio_direction_in,
 189         .direction_output       = max3107_gpio_direction_out,
 190         .get                    = max3107_gpio_get,
 191         .set                    = max3107_gpio_set,
 192         .can_sleep              = 1,
 193         .base                   = MAX3107_GPIO_BASE,
 194         .ngpio                  = MAX3107_GPIO_COUNT,
 195 };
 196
 197 /**
 198  *      max3107_aava_reset      -       reset on AAVA systems
 199  *      @spi: The SPI device we are probing
 200  *
 201  *      Reset the device ready for probing.
 202  */
 203
 204 static int max3107_aava_reset(struct spi_device *spi)
 205 {
 206         /* Reset the chip */
 207         if (gpio_request(MAX3107_RESET_GPIO, "max3107")) {
 208                 pr_err("Requesting RESET GPIO failed\n");
 209                 return -EIO;
 210         }
 211         if (gpio_direction_output(MAX3107_RESET_GPIO, 0)) {
 212                 pr_err("Setting RESET GPIO to 0 failed\n");
 213                 gpio_free(MAX3107_RESET_GPIO);
 214                 return -EIO;
 215         }
 216         msleep(MAX3107_RESET_DELAY);
 217         if (gpio_direction_output(MAX3107_RESET_GPIO, 1)) {
 218                 pr_err("Setting RESET GPIO to 1 failed\n");
 219                 gpio_free(MAX3107_RESET_GPIO);
 220                 return -EIO;
 221         }
 222         gpio_free(MAX3107_RESET_GPIO);
 223         msleep(MAX3107_WAKEUP_DELAY);
 224         return 0;
 225 }
 226
 227 static int max3107_aava_configure(struct max3107_port *s)
 228 {
 229         int retval;
 230
 231         /* Initialize GPIO chip data */
 232         s->chip = max3107_gpio_chip;
 233         s->chip.label = s->spi->modalias;
 234         s->chip.dev = &s->spi->dev;
 235
 236         /* Add GPIO chip */
 237         retval = gpiochip_add(&s->chip);
 238         if (retval) {
 239                 dev_err(&s->spi->dev, "Adding GPIO chip failed\n");
 240                 return retval;
 241         }
 242
 243         /* Temporary fix for EV2 boot problems, set modem reset to 0 */
 244         max3107_gpio_direction_out(&s->chip, 3, 0);
 245         return 0;
 246 }
 247
 248 #if 0
 249 /* This will get enabled once we have the board stuff merged for this
 250    specific case */
 251
 252 static const struct baud_table brg13_ext[] = {
 253         { 300,    MAX3107_BRG13_B300 },
 254         { 600,    MAX3107_BRG13_B600 },
 255         { 1200,   MAX3107_BRG13_B1200 },
 256         { 2400,   MAX3107_BRG13_B2400 },
 257         { 4800,   MAX3107_BRG13_B4800 },
 258         { 9600,   MAX3107_BRG13_B9600 },
 259         { 19200,  MAX3107_BRG13_B19200 },
 260         { 57600,  MAX3107_BRG13_B57600 },
 261         { 115200, MAX3107_BRG13_B115200 },
 262         { 230400, MAX3107_BRG13_B230400 },
 263         { 460800, MAX3107_BRG13_B460800 },
 264         { 921600, MAX3107_BRG13_B921600 },
 265         { 0, 0 }
 266 };
 267
 268 static void max3107_aava_init(struct max3107_port *s)
 269 {
 270         /*override for AAVA SC specific*/
 271         if (mrst_platform_id() == MRST_PLATFORM_AAVA_SC) {
 272                 if (get_koski_build_id() <= KOSKI_EV2)
 273                         if (s->ext_clk) {
 274                                 s->brg_cfg = MAX3107_BRG13_B9600;
 275                                 s->baud_tbl = (struct baud_table *)brg13_ext;
 276                         }
 277         }
 278 }
 279 #endif
 280
 281 static int __devexit max3107_aava_remove(struct spi_device *spi)
 282 {
 283         struct max3107_port *s = dev_get_drvdata(&spi->dev);
 284
 285         /* Remove GPIO chip */
 286         if (gpiochip_remove(&s->chip))
 287                 dev_warn(&spi->dev, "Removing GPIO chip failed\n");
 288
 289         /* Then do the default remove */
 290         return max3107_remove(spi);
 291 }
 292
 293 /* Platform data */
 294 static struct max3107_plat aava_plat_data = {
 295         .loopback               = 0,
 296         .ext_clk                = 1,
 297 /*      .init                   = max3107_aava_init, */
 298         .configure              = max3107_aava_configure,
 299         .hw_suspend             = max3107_hw_susp,
 300         .polled_mode            = 0,
 301         .poll_time              = 0,
 302 };
 303
 304
 305 static int __devinit max3107_probe_aava(struct spi_device *spi)
 306 {
 307         int err = max3107_aava_reset(spi);
 308         if (err < 0)
 309                 return err;
 310         return max3107_probe(spi, &aava_plat_data);
 311 }
 312
 313 /* Spi driver data */
 314 static struct spi_driver max3107_driver = {
 315         .driver = {
 316                 .name           = "aava-max3107",
 317                 .bus            = &spi_bus_type,
 318                 .owner          = THIS_MODULE,
 319         },
 320         .probe          = max3107_probe_aava,
 321         .remove         = __devexit_p(max3107_aava_remove),
 322         .suspend        = max3107_suspend,
 323         .resume         = max3107_resume,
 324 };
 325
 326 /* Driver init function */
 327 static int __init max3107_init(void)
 328 {
 329         return spi_register_driver(&max3107_driver);
 330 }
 331
 332 /* Driver exit function */
 333 static void __exit max3107_exit(void)
 334 {
 335         spi_unregister_driver(&max3107_driver);
 336 }
 337
 338 module_init(max3107_init);
 339 module_exit(max3107_exit);
 340
 341 MODULE_DESCRIPTION("MAX3107 driver");
 342 MODULE_AUTHOR("Aavamobile");
 343 MODULE_ALIAS("aava-max3107-spi");
 344 MODULE_LICENSE("GPL v2");