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 actually supports the TS-5500 platform, but it may be extended to
  19  * support similar Technologic Systems x86-based platforms, such as the TS-5600.
  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/module.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
  36 /* SRAM/RS-485/ADC options, and RS-485 RTS/Automatic RS-485 flags register */
  37 #define TS5500_SRAM_RS485_ADC_ADDR      0x75
  38 #define TS5500_SRAM                     BIT(0)  /* SRAM option */
  39 #define TS5500_RS485                    BIT(1)  /* RS-485 option */
  40 #define TS5500_ADC                      BIT(2)  /* A/D converter option */
  41 #define TS5500_RS485_RTS                BIT(6)  /* RTS for RS-485 */
  42 #define TS5500_RS485_AUTO               BIT(7)  /* Automatic RS-485 */
  43
  44 /* External Reset/Industrial Temperature Range options register */
  45 #define TS5500_ERESET_ITR_ADDR          0x76
  46 #define TS5500_ERESET                   BIT(0)  /* External Reset option */
  47 #define TS5500_ITR                      BIT(1)  /* Indust. Temp. Range option */
  48
  49 /* LED/Jumpers register */
  50 #define TS5500_LED_JP_ADDR              0x77
  51 #define TS5500_LED                      BIT(0)  /* LED flag */
  52 #define TS5500_JP1                      BIT(1)  /* Automatic CMOS */
  53 #define TS5500_JP2                      BIT(2)  /* Enable Serial Console */
  54 #define TS5500_JP3                      BIT(3)  /* Write Enable Drive A */
  55 #define TS5500_JP4                      BIT(4)  /* Fast Console (115K baud) */
  56 #define TS5500_JP5                      BIT(5)  /* User Jumper */
  57 #define TS5500_JP6                      BIT(6)  /* Console on COM1 (req. JP2) */
  58 #define TS5500_JP7                      BIT(7)  /* Undocumented (Unused) */
  59
  60 /* A/D Converter registers */
  61 #define TS5500_ADC_CONV_BUSY_ADDR       0x195   /* Conversion state register */
  62 #define TS5500_ADC_CONV_BUSY            BIT(0)
  63 #define TS5500_ADC_CONV_INIT_LSB_ADDR   0x196   /* Start conv. / LSB register */
  64 #define TS5500_ADC_CONV_MSB_ADDR        0x197   /* MSB register */
  65 #define TS5500_ADC_CONV_DELAY           12      /* usec */
  66
  67 /**
  68  * struct ts5500_sbc - TS-5500 board description
  69  * @name:       Board model name.
  70  * @id:         Board product ID.
  71  * @sram:       Flag for SRAM option.
  72  * @rs485:      Flag for RS-485 option.
  73  * @adc:        Flag for Analog/Digital converter option.
  74  * @ereset:     Flag for External Reset option.
  75  * @itr:        Flag for Industrial Temperature Range option.
  76  * @jumpers:    Bitfield for jumpers' state.
  77  */
  78 struct ts5500_sbc {
  79         const char *name;
  80         int     id;
  81         bool    sram;
  82         bool    rs485;
  83         bool    adc;
  84         bool    ereset;
  85         bool    itr;
  86         u8      jumpers;
  87 };
  88
  89 /* Board signatures in BIOS shadow RAM */
  90 static const struct {
  91         const char * const string;
  92         const ssize_t offset;
  93 } ts5500_signatures[] __initconst = {
  94         { "TS-5x00 AMD Elan", 0xb14 },
  95 };
  96
  97 static int __init ts5500_check_signature(void)
  98 {
  99         void __iomem *bios;
 100         int i, ret = -ENODEV;
 101
 102         bios = ioremap(0xf0000, 0x10000);
 103         if (!bios)
 104                 return -ENOMEM;
 105
 106         for (i = 0; i < ARRAY_SIZE(ts5500_signatures); i++) {
 107                 if (check_signature(bios + ts5500_signatures[i].offset,
 108                                     ts5500_signatures[i].string,
 109                                     strlen(ts5500_signatures[i].string))) {
 110                         ret = 0;
 111                         break;
 112                 }
 113         }
 114
 115         iounmap(bios);
 116         return ret;
 117 }
 118
 119 static int __init ts5500_detect_config(struct ts5500_sbc *sbc)
 120 {
 121         u8 tmp;
 122         int ret = 0;
 123
 124         if (!request_region(TS5500_PRODUCT_CODE_ADDR, 4, "ts5500"))
 125                 return -EBUSY;
 126
 127         sbc->id = inb(TS5500_PRODUCT_CODE_ADDR);
 128         if (sbc->id == TS5500_PRODUCT_CODE) {
 129                 sbc->name = "TS-5500";
 130         } else {
 131                 pr_err("ts5500: unknown product code 0x%x\n", sbc->id);
 132                 ret = -ENODEV;
 133                 goto cleanup;
 134         }
 135
 136         tmp = inb(TS5500_SRAM_RS485_ADC_ADDR);
 137         sbc->sram = tmp & TS5500_SRAM;
 138         sbc->rs485 = tmp & TS5500_RS485;
 139         sbc->adc = tmp & TS5500_ADC;
 140
 141         tmp = inb(TS5500_ERESET_ITR_ADDR);
 142         sbc->ereset = tmp & TS5500_ERESET;
 143         sbc->itr = tmp & TS5500_ITR;
 144
 145         tmp = inb(TS5500_LED_JP_ADDR);
 146         sbc->jumpers = tmp & ~TS5500_LED;
 147
 148 cleanup:
 149         release_region(TS5500_PRODUCT_CODE_ADDR, 4);
 150         return ret;
 151 }
 152
 153 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 154                 char *buf)
 155 {
 156         struct ts5500_sbc *sbc = dev_get_drvdata(dev);
 157
 158         return sprintf(buf, "%s\n", sbc->name);
 159 }
 160 static DEVICE_ATTR_RO(name);
 161
 162 static ssize_t id_show(struct device *dev, struct device_attribute *attr,
 163                 char *buf)
 164 {
 165         struct ts5500_sbc *sbc = dev_get_drvdata(dev);
 166
 167         return sprintf(buf, "0x%.2x\n", sbc->id);
 168 }
 169 static DEVICE_ATTR_RO(id);
 170
 171 static ssize_t jumpers_show(struct device *dev, struct device_attribute *attr,
 172                 char *buf)
 173 {
 174         struct ts5500_sbc *sbc = dev_get_drvdata(dev);
 175
 176         return sprintf(buf, "0x%.2x\n", sbc->jumpers >> 1);
 177 }
 178 static DEVICE_ATTR_RO(jumpers);
 179
 180 #define TS5500_ATTR_BOOL(_field)                                        \
 181         static ssize_t _field##_show(struct device *dev,                \
 182                         struct device_attribute *attr, char *buf)       \
 183         {                                                               \
 184                 struct ts5500_sbc *sbc = dev_get_drvdata(dev);          \
 185                                                                         \
 186                 return sprintf(buf, "%d\n", sbc->_field);               \
 187         }                                                               \
 188         static DEVICE_ATTR_RO(_field)
 189
 190 TS5500_ATTR_BOOL(sram);
 191 TS5500_ATTR_BOOL(rs485);
 192 TS5500_ATTR_BOOL(adc);
 193 TS5500_ATTR_BOOL(ereset);
 194 TS5500_ATTR_BOOL(itr);
 195
 196 static struct attribute *ts5500_attributes[] = {
 197         &dev_attr_id.attr,
 198         &dev_attr_name.attr,
 199         &dev_attr_jumpers.attr,
 200         &dev_attr_sram.attr,
 201         &dev_attr_rs485.attr,
 202         &dev_attr_adc.attr,
 203         &dev_attr_ereset.attr,
 204         &dev_attr_itr.attr,
 205         NULL
 206 };
 207
 208 static const struct attribute_group ts5500_attr_group = {
 209         .attrs = ts5500_attributes,
 210 };
 211
 212 static struct resource ts5500_dio1_resource[] = {
 213         DEFINE_RES_IRQ_NAMED(7, "DIO1 interrupt"),
 214 };
 215
 216 static struct platform_device ts5500_dio1_pdev = {
 217         .name = "ts5500-dio1",
 218         .id = -1,
 219         .resource = ts5500_dio1_resource,
 220         .num_resources = 1,
 221 };
 222
 223 static struct resource ts5500_dio2_resource[] = {
 224         DEFINE_RES_IRQ_NAMED(6, "DIO2 interrupt"),
 225 };
 226
 227 static struct platform_device ts5500_dio2_pdev = {
 228         .name = "ts5500-dio2",
 229         .id = -1,
 230         .resource = ts5500_dio2_resource,
 231         .num_resources = 1,
 232 };
 233
 234 static void ts5500_led_set(struct led_classdev *led_cdev,
 235                            enum led_brightness brightness)
 236 {
 237         outb(!!brightness, TS5500_LED_JP_ADDR);
 238 }
 239
 240 static enum led_brightness ts5500_led_get(struct led_classdev *led_cdev)
 241 {
 242         return (inb(TS5500_LED_JP_ADDR) & TS5500_LED) ? LED_FULL : LED_OFF;
 243 }
 244
 245 static struct led_classdev ts5500_led_cdev = {
 246         .name = "ts5500:green:",
 247         .brightness_set = ts5500_led_set,
 248         .brightness_get = ts5500_led_get,
 249 };
 250
 251 static int ts5500_adc_convert(u8 ctrl)
 252 {
 253         u8 lsb, msb;
 254
 255         /* Start conversion (ensure the 3 MSB are set to 0) */
 256         outb(ctrl & 0x1f, TS5500_ADC_CONV_INIT_LSB_ADDR);
 257
 258         /*
 259          * The platform has CPLD logic driving the A/D converter.
 260          * The conversion must complete within 11 microseconds,
 261          * otherwise we have to re-initiate a conversion.
 262          */
 263         udelay(TS5500_ADC_CONV_DELAY);
 264         if (inb(TS5500_ADC_CONV_BUSY_ADDR) & TS5500_ADC_CONV_BUSY)
 265                 return -EBUSY;
 266
 267         /* Read the raw data */
 268         lsb = inb(TS5500_ADC_CONV_INIT_LSB_ADDR);
 269         msb = inb(TS5500_ADC_CONV_MSB_ADDR);
 270
 271         return (msb << 8) | lsb;
 272 }
 273
 274 static struct max197_platform_data ts5500_adc_pdata = {
 275         .convert = ts5500_adc_convert,
 276 };
 277
 278 static struct platform_device ts5500_adc_pdev = {
 279         .name = "max197",
 280         .id = -1,
 281         .dev = {
 282                 .platform_data = &ts5500_adc_pdata,
 283         },
 284 };
 285
 286 static int __init ts5500_init(void)
 287 {
 288         struct platform_device *pdev;
 289         struct ts5500_sbc *sbc;
 290         int err;
 291
 292         /*
 293          * There is no DMI available or PCI bridge subvendor info,
 294          * only the BIOS provides a 16-bit identification call.
 295          * It is safer to find a signature in the BIOS shadow RAM.
 296          */
 297         err = ts5500_check_signature();
 298         if (err)
 299                 return err;
 300
 301         pdev = platform_device_register_simple("ts5500", -1, NULL, 0);
 302         if (IS_ERR(pdev))
 303                 return PTR_ERR(pdev);
 304
 305         sbc = devm_kzalloc(&pdev->dev, sizeof(struct ts5500_sbc), GFP_KERNEL);
 306         if (!sbc) {
 307                 err = -ENOMEM;
 308                 goto error;
 309         }
 310
 311         err = ts5500_detect_config(sbc);
 312         if (err)
 313                 goto error;
 314
 315         platform_set_drvdata(pdev, sbc);
 316
 317         err = sysfs_create_group(&pdev->dev.kobj, &ts5500_attr_group);
 318         if (err)
 319                 goto error;
 320
 321         ts5500_dio1_pdev.dev.parent = &pdev->dev;
 322         if (platform_device_register(&ts5500_dio1_pdev))
 323                 dev_warn(&pdev->dev, "DIO1 block registration failed\n");
 324         ts5500_dio2_pdev.dev.parent = &pdev->dev;
 325         if (platform_device_register(&ts5500_dio2_pdev))
 326                 dev_warn(&pdev->dev, "DIO2 block registration failed\n");
 327
 328         if (led_classdev_register(&pdev->dev, &ts5500_led_cdev))
 329                 dev_warn(&pdev->dev, "LED registration failed\n");
 330
 331         if (sbc->adc) {
 332                 ts5500_adc_pdev.dev.parent = &pdev->dev;
 333                 if (platform_device_register(&ts5500_adc_pdev))
 334                         dev_warn(&pdev->dev, "ADC registration failed\n");
 335         }
 336
 337         return 0;
 338 error:
 339         platform_device_unregister(pdev);
 340         return err;
 341 }
 342 device_initcall(ts5500_init);
 343
 344 MODULE_LICENSE("GPL");
 345 MODULE_AUTHOR("Savoir-faire Linux Inc. <kernel@savoirfairelinux.com>");
 346 MODULE_DESCRIPTION("Technologic Systems TS-5500 platform driver");