arch/x86/platform/ts5500/ts5500.c

   1 /*
   2  * Technologic Systems TS-5500 Single Board Computer support
   3  *
   4  * Copyright (C) 2013-2014 Savoir-faire Linux Inc.
   5  *      Vivien Didelot <vivien.didelot@savoirfairelinux.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it under
   8  * the terms of the GNU General Public License as published by the Free Software
   9  * Foundation; either version 2 of the License, or (at your option) any later
  10  * version.
  11  *
  12  *
  13  * This driver registers the Technologic Systems TS-5500 Single Board Computer
  14  * (SBC) and its devices, and exposes information to userspace such as jumpers'
  15  * state or available options. For further information about sysfs entries, see
  16  * Documentation/ABI/testing/sysfs-platform-ts5500.
  17  *
  18  * This code may be extended to support similar x86-based platforms.
  19  * Actually, the TS-5500 and TS-5400 are supported.
  20  */
  21
  22 #include <linux/delay.h>
  23 #include <linux/io.h>
  24 #include <linux/kernel.h>
  25 #include <linux/leds.h>
  26 #include <linux/init.h>
  27 #include <linux/platform_data/gpio-ts5500.h>
  28 #include <linux/platform_data/max197.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/slab.h>
  31
  32 /* Product code register */
  33 #define TS5500_PRODUCT_CODE_ADDR        0x74
  34 #define TS5500_PRODUCT_CODE             0x60    /* TS-5500 product code */
  35 #define TS5400_PRODUCT_CODE             0x40    /* TS-5400 product code */
  36
  37 /* SRAM/RS-485/ADC options, and RS-485 RTS/Automatic RS-485 flags register */
  38 #define TS5500_SRAM_RS485_ADC_ADDR      0x75
  39 #define TS5500_SRAM                     BIT(0)  /* SRAM option */
  40 #define TS5500_RS485                    BIT(1)  /* RS-485 option */
  41 #define TS5500_ADC                      BIT(2)  /* A/D converter option */
  42 #define TS5500_RS485_RTS                BIT(6)  /* RTS for RS-485 */
  43 #define TS5500_RS485_AUTO               BIT(7)  /* Automatic RS-485 */
  44
  45 /* External Reset/Industrial Temperature Range options register */
  46 #define TS5500_ERESET_ITR_ADDR          0x76
  47 #define TS5500_ERESET                   BIT(0)  /* External Reset option */
  48 #define TS5500_ITR                      BIT(1)  /* Indust. Temp. Range option */
  49
  50 /* LED/Jumpers register */
  51 #define TS5500_LED_JP_ADDR              0x77
  52 #define TS5500_LED                      BIT(0)  /* LED flag */
  53 #define TS5500_JP1                      BIT(1)  /* Automatic CMOS */
  54 #define TS5500_JP2                      BIT(2)  /* Enable Serial Console */
  55 #define TS5500_JP3                      BIT(3)  /* Write Enable Drive A */
  56 #define TS5500_JP4                      BIT(4)  /* Fast Console (115K baud) */
  57 #define TS5500_JP5                      BIT(5)  /* User Jumper */
  58 #define TS5500_JP6                      BIT(6)  /* Console on COM1 (req. JP2) */
  59 #define TS5500_JP7                      BIT(7)  /* Undocumented (Unused) */
  60
  61 /* A/D Converter registers */
  62 #define TS5500_ADC_CONV_BUSY_ADDR       0x195   /* Conversion state register */
  63 #define TS5500_ADC_CONV_BUSY            BIT(0)
  64 #define TS5500_ADC_CONV_INIT_LSB_ADDR   0x196   /* Start conv. / LSB register */
  65 #define TS5500_ADC_CONV_MSB_ADDR        0x197   /* MSB register */
  66 #define TS5500_ADC_CONV_DELAY           12      /* usec */
  67
  68 /**
  69  * struct ts5500_sbc - TS-5500 board description
  70  * @name:       Board model name.
  71  * @id:         Board product ID.
  72  * @sram:       Flag for SRAM option.
  73  * @rs485:      Flag for RS-485 option.
  74  * @adc:        Flag for Analog/Digital converter option.
  75  * @ereset:     Flag for External Reset option.
  76  * @itr:        Flag for Industrial Temperature Range option.
  77  * @jumpers:    Bitfield for jumpers' state.
  78  */
  79 struct ts5500_sbc {
  80         const char *name;
  81         int     id;
  82         bool    sram;
  83         bool    rs485;
  84         bool    adc;
  85         bool    ereset;
  86         bool    itr;
  87         u8      jumpers;
  88 };
  89
  90 /* Board signatures in BIOS shadow RAM */
  91 static const struct {
  92         const char * const string;
  93         const ssize_t offset;
  94 } ts5500_signatures[] __initconst = {
  95         { "TS-5x00 AMD Elan", 0xb14 },
  96 };
  97
  98 static int __init ts5500_check_signature(void)
  99 {
 100         void __iomem *bios;
 101         int i, ret = -ENODEV;
 102
 103         bios = ioremap(0xf0000, 0x10000);
 104         if (!bios)
 105                 return -ENOMEM;
 106
 107         for (i = 0; i < ARRAY_SIZE(ts5500_signatures); i++) {
 108                 if (check_signature(bios + ts5500_signatures[i].offset,
 109                                     ts5500_signatures[i].string,
 110                                     strlen(ts5500_signatures[i].string))) {
 111                         ret = 0;
 112                         break;
 113                 }
 114         }
 115
 116         iounmap(bios);
 117         return ret;
 118 }
 119
 120 static int __init ts5500_detect_config(struct ts5500_sbc *sbc)
 121 {
 122         u8 tmp;
 123         int ret = 0;
 124
 125         if (!request_region(TS5500_PRODUCT_CODE_ADDR, 4, "ts5500"))
 126                 return -EBUSY;
 127
 128         sbc->id = inb(TS5500_PRODUCT_CODE_ADDR);
 129         if (sbc->id == TS5500_PRODUCT_CODE) {
 130                 sbc->name = "TS-5500";
 131         } else if (sbc->id == TS5400_PRODUCT_CODE) {
 132                 sbc->name = "TS-5400";
 133         } else {
 134                 pr_err("ts5500: unknown product code 0x%x\n", sbc->id);
 135                 ret = -ENODEV;
 136                 goto cleanup;
 137         }
 138
 139         tmp = inb(TS5500_SRAM_RS485_ADC_ADDR);
 140         sbc->sram = tmp & TS5500_SRAM;
 141         sbc->rs485 = tmp & TS5500_RS485;
 142         sbc->adc = tmp & TS5500_ADC;
 143
 144         tmp = inb(TS5500_ERESET_ITR_ADDR);
 145         sbc->ereset = tmp & TS5500_ERESET;
 146         sbc->itr = tmp & TS5500_ITR;
 147
 148         tmp = inb(TS5500_LED_JP_ADDR);
 149         sbc->jumpers = tmp & ~TS5500_LED;
 150
 151 cleanup:
 152         release_region(TS5500_PRODUCT_CODE_ADDR, 4);
 153         return ret;
 154 }
 155
 156 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 157                 char *buf)
 158 {
 159         struct ts5500_sbc *sbc = dev_get_drvdata(dev);
 160
 161         return sprintf(buf, "%s\n", sbc->name);
 162 }
 163 static DEVICE_ATTR_RO(name);
 164
 165 static ssize_t id_show(struct device *dev, struct device_attribute *attr,
 166                 char *buf)
 167 {
 168         struct ts5500_sbc *sbc = dev_get_drvdata(dev);
 169
 170         return sprintf(buf, "0x%.2x\n", sbc->id);
 171 }
 172 static DEVICE_ATTR_RO(id);
 173
 174 static ssize_t jumpers_show(struct device *dev, struct device_attribute *attr,
 175                 char *buf)
 176 {
 177         struct ts5500_sbc *sbc = dev_get_drvdata(dev);
 178
 179         return sprintf(buf, "0x%.2x\n", sbc->jumpers >> 1);
 180 }
 181 static DEVICE_ATTR_RO(jumpers);
 182
 183 #define TS5500_ATTR_BOOL(_field)                                        \
 184         static ssize_t _field##_show(struct device *dev,                \
 185                         struct device_attribute *attr, char *buf)       \
 186         {                                                               \
 187                 struct ts5500_sbc *sbc = dev_get_drvdata(dev);          \
 188                                                                         \
 189                 return sprintf(buf, "%d\n", sbc->_field);               \
 190         }                                                               \
 191         static DEVICE_ATTR_RO(_field)
 192
 193 TS5500_ATTR_BOOL(sram);
 194 TS5500_ATTR_BOOL(rs485);
 195 TS5500_ATTR_BOOL(adc);
 196 TS5500_ATTR_BOOL(ereset);
 197 TS5500_ATTR_BOOL(itr);
 198
 199 static struct attribute *ts5500_attributes[] = {
 200         &dev_attr_id.attr,
 201         &dev_attr_name.attr,
 202         &dev_attr_jumpers.attr,
 203         &dev_attr_sram.attr,
 204         &dev_attr_rs485.attr,
 205         &dev_attr_adc.attr,
 206         &dev_attr_ereset.attr,
 207         &dev_attr_itr.attr,
 208         NULL
 209 };
 210
 211 static const struct attribute_group ts5500_attr_group = {
 212         .attrs = ts5500_attributes,
 213 };
 214
 215 static struct resource ts5500_dio1_resource[] = {
 216         DEFINE_RES_IRQ_NAMED(7, "DIO1 interrupt"),
 217 };
 218
 219 static struct platform_device ts5500_dio1_pdev = {
 220         .name = "ts5500-dio1",
 221         .id = -1,
 222         .resource = ts5500_dio1_resource,
 223         .num_resources = 1,
 224 };
 225
 226 static struct resource ts5500_dio2_resource[] = {
 227         DEFINE_RES_IRQ_NAMED(6, "DIO2 interrupt"),
 228 };
 229
 230 static struct platform_device ts5500_dio2_pdev = {
 231         .name = "ts5500-dio2",
 232         .id = -1,
 233         .resource = ts5500_dio2_resource,
 234         .num_resources = 1,
 235 };
 236
 237 static void ts5500_led_set(struct led_classdev *led_cdev,
 238                            enum led_brightness brightness)
 239 {
 240         outb(!!brightness, TS5500_LED_JP_ADDR);
 241 }
 242
 243 static enum led_brightness ts5500_led_get(struct led_classdev *led_cdev)
 244 {
 245         return (inb(TS5500_LED_JP_ADDR) & TS5500_LED) ? LED_FULL : LED_OFF;
 246 }
 247
 248 static struct led_classdev ts5500_led_cdev = {
 249         .name = "ts5500:green:",
 250         .brightness_set = ts5500_led_set,
 251         .brightness_get = ts5500_led_get,
 252 };
 253
 254 static int ts5500_adc_convert(u8 ctrl)
 255 {
 256         u8 lsb, msb;
 257
 258         /* Start conversion (ensure the 3 MSB are set to 0) */
 259         outb(ctrl & 0x1f, TS5500_ADC_CONV_INIT_LSB_ADDR);
 260
 261         /*
 262          * The platform has CPLD logic driving the A/D converter.
 263          * The conversion must complete within 11 microseconds,
 264          * otherwise we have to re-initiate a conversion.
 265          */
 266         udelay(TS5500_ADC_CONV_DELAY);
 267         if (inb(TS5500_ADC_CONV_BUSY_ADDR) & TS5500_ADC_CONV_BUSY)
 268                 return -EBUSY;
 269
 270         /* Read the raw data */
 271         lsb = inb(TS5500_ADC_CONV_INIT_LSB_ADDR);
 272         msb = inb(TS5500_ADC_CONV_MSB_ADDR);
 273
 274         return (msb << 8) | lsb;
 275 }
 276
 277 static struct max197_platform_data ts5500_adc_pdata = {
 278         .convert = ts5500_adc_convert,
 279 };
 280
 281 static struct platform_device ts5500_adc_pdev = {
 282         .name = "max197",
 283         .id = -1,
 284         .dev = {
 285                 .platform_data = &ts5500_adc_pdata,
 286         },
 287 };
 288
 289 static int __init ts5500_init(void)
 290 {
 291         struct platform_device *pdev;
 292         struct ts5500_sbc *sbc;
 293         int err;
 294
 295         /*
 296          * There is no DMI available or PCI bridge subvendor info,
 297          * only the BIOS provides a 16-bit identification call.
 298          * It is safer to find a signature in the BIOS shadow RAM.
 299          */
 300         err = ts5500_check_signature();
 301         if (err)
 302                 return err;
 303
 304         pdev = platform_device_register_simple("ts5500", -1, NULL, 0);
 305         if (IS_ERR(pdev))
 306                 return PTR_ERR(pdev);
 307
 308         sbc = devm_kzalloc(&pdev->dev, sizeof(struct ts5500_sbc), GFP_KERNEL);
 309         if (!sbc) {
 310                 err = -ENOMEM;
 311                 goto error;
 312         }
 313
 314         err = ts5500_detect_config(sbc);
 315         if (err)
 316                 goto error;
 317
 318         platform_set_drvdata(pdev, sbc);
 319
 320         err = sysfs_create_group(&pdev->dev.kobj, &ts5500_attr_group);
 321         if (err)
 322                 goto error;
 323
 324         if (sbc->id == TS5500_PRODUCT_CODE) {
 325                 ts5500_dio1_pdev.dev.parent = &pdev->dev;
 326                 if (platform_device_register(&ts5500_dio1_pdev))
 327                         dev_warn(&pdev->dev, "DIO1 block registration failed\n");
 328                 ts5500_dio2_pdev.dev.parent = &pdev->dev;
 329                 if (platform_device_register(&ts5500_dio2_pdev))
 330                         dev_warn(&pdev->dev, "DIO2 block registration failed\n");
 331         }
 332
 333         if (led_classdev_register(&pdev->dev, &ts5500_led_cdev))
 334                 dev_warn(&pdev->dev, "LED registration failed\n");
 335
 336         if (sbc->adc) {
 337                 ts5500_adc_pdev.dev.parent = &pdev->dev;
 338                 if (platform_device_register(&ts5500_adc_pdev))
 339                         dev_warn(&pdev->dev, "ADC registration failed\n");
 340         }
 341
 342         return 0;
 343 error:
 344         platform_device_unregister(pdev);
 345         return err;
 346 }
 347 device_initcall(ts5500_init);