ArmPlatformPkg/Drivers/PL061GpioDxe/PL061Gpio.c

   1 /** @file
   2 *
   3 *  Copyright (c) 2011, ARM Limited. All rights reserved.
   4 *  Copyright (c) 2016, Linaro Limited. All rights reserved.
   5 *
   6 *  This program and the accompanying materials
   7 *  are licensed and made available under the terms and conditions of the BSD
   8 *  License which accompanies this distribution.  The full text of the license
   9 *  may be found at http://opensource.org/licenses/bsd-license.php
  10 *
  11 *  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12 *  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13 *
  14 **/
  15
  16
  17 #include <PiDxe.h>
  18
  19 #include <Library/BaseLib.h>
  20 #include <Library/BaseMemoryLib.h>
  21 #include <Library/DebugLib.h>
  22 #include <Library/IoLib.h>
  23 #include <Library/PcdLib.h>
  24 #include <Library/UefiBootServicesTableLib.h>
  25 #include <Library/UefiLib.h>
  26 #include <Library/UefiRuntimeServicesTableLib.h>
  27
  28 #include <Protocol/EmbeddedGpio.h>
  29 #include <Drivers/PL061Gpio.h>
  30
  31 //
  32 // The PL061 is a strange beast. The 8-bit data register is aliased across a
  33 // region 0x400 bytes in size, with bits [9:2] of the address operating as a
  34 // mask for both read and write operations:
  35 // For reads:
  36 //   - All bits where their corresponding mask bit is 1 return the current
  37 //     value of that bit in the GPIO_DATA register.
  38 //   - All bits where their corresponding mask bit is 0 return 0.
  39 // For writes:
  40 //   - All bits where their corresponding mask bit is 1 set the bit in the
  41 //     GPIO_DATA register to the written value.
  42 //   - All bits where their corresponding mask bit is 0 are left untouched
  43 //     in the GPIO_DATA register.
  44 //
  45 // To keep this driver intelligible, PL061EffectiveAddress, PL061GetPins and
  46 // Pl061SetPins provide an internal abstraction from this interface.
  47
  48 STATIC
  49 UINTN
  50 EFIAPI
  51 PL061EffectiveAddress (
  52   IN UINTN Address,
  53   IN UINTN Mask
  54   )
  55 {
  56   return ((Address + PL061_GPIO_DATA_REG_OFFSET) + (Mask << 2));
  57 }
  58
  59 STATIC
  60 UINTN
  61 EFIAPI
  62 PL061GetPins (
  63   IN UINTN Address,
  64   IN UINTN Mask
  65   )
  66 {
  67   return MmioRead8 (PL061EffectiveAddress (Address, Mask));
  68 }
  69
  70 STATIC
  71 VOID
  72 EFIAPI
  73 PL061SetPins (
  74   IN UINTN Address,
  75   IN UINTN Mask,
  76   IN UINTN Value
  77   )
  78 {
  79   MmioWrite8 (PL061EffectiveAddress (Address, Mask), Value);
  80 }
  81
  82 /**
  83   Function implementations
  84 **/
  85
  86 EFI_STATUS
  87 PL061Identify (
  88   VOID
  89   )
  90 {
  91   // Check if this is a PrimeCell Peripheral
  92   if (    (MmioRead8 (PL061_GPIO_PCELL_ID0) != 0x0D)
  93       ||  (MmioRead8 (PL061_GPIO_PCELL_ID1) != 0xF0)
  94       ||  (MmioRead8 (PL061_GPIO_PCELL_ID2) != 0x05)
  95       ||  (MmioRead8 (PL061_GPIO_PCELL_ID3) != 0xB1)) {
  96     return EFI_NOT_FOUND;
  97   }
  98
  99   // Check if this PrimeCell Peripheral is the PL061 GPIO
 100   if (    (MmioRead8 (PL061_GPIO_PERIPH_ID0) != 0x61)
 101       ||  (MmioRead8 (PL061_GPIO_PERIPH_ID1) != 0x10)
 102       ||  ((MmioRead8 (PL061_GPIO_PERIPH_ID2) & 0xF) != 0x04)
 103       ||  (MmioRead8 (PL061_GPIO_PERIPH_ID3) != 0x00)) {
 104     return EFI_NOT_FOUND;
 105   }
 106
 107   return EFI_SUCCESS;
 108 }
 109
 110 /**
 111
 112 Routine Description:
 113
 114   Gets the state of a GPIO pin
 115
 116 Arguments:
 117
 118   This  - pointer to protocol
 119   Gpio  - which pin to read
 120   Value - state of the pin
 121
 122 Returns:
 123
 124   EFI_SUCCESS           - GPIO state returned in Value
 125   EFI_INVALID_PARAMETER - Value is NULL pointer or Gpio pin is out of range
 126 **/
 127 EFI_STATUS
 128 EFIAPI
 129 Get (
 130   IN  EMBEDDED_GPIO     *This,
 131   IN  EMBEDDED_GPIO_PIN Gpio,
 132   OUT UINTN             *Value
 133   )
 134 {
 135   if (    (Value == NULL)
 136       ||  (Gpio > LAST_GPIO_PIN))
 137   {
 138     return EFI_INVALID_PARAMETER;
 139   }
 140
 141   if (PL061GetPins (PL061_GPIO_DATA_REG, Gpio)) {
 142     *Value = 1;
 143   } else {
 144     *Value = 0;
 145   }
 146
 147   return EFI_SUCCESS;
 148 }
 149
 150 /**
 151
 152 Routine Description:
 153
 154   Sets the state of a GPIO pin
 155
 156 Arguments:
 157
 158   This  - pointer to protocol
 159   Gpio  - which pin to modify
 160   Mode  - mode to set
 161
 162 Returns:
 163
 164   EFI_SUCCESS           - GPIO set as requested
 165   EFI_UNSUPPORTED       - Mode is not supported
 166   EFI_INVALID_PARAMETER - Gpio pin is out of range
 167 **/
 168 EFI_STATUS
 169 EFIAPI
 170 Set (
 171   IN  EMBEDDED_GPIO       *This,
 172   IN  EMBEDDED_GPIO_PIN   Gpio,
 173   IN  EMBEDDED_GPIO_MODE  Mode
 174   )
 175 {
 176   EFI_STATUS    Status = EFI_SUCCESS;
 177
 178   // Check for errors
 179   if (Gpio > LAST_GPIO_PIN) {
 180     Status = EFI_INVALID_PARAMETER;
 181     goto EXIT;
 182   }
 183
 184   switch (Mode)
 185   {
 186     case GPIO_MODE_INPUT:
 187       // Set the corresponding direction bit to LOW for input
 188       MmioAnd8 (PL061_GPIO_DIR_REG, ~GPIO_PIN_MASK(Gpio) & 0xFF);
 189       break;
 190
 191     case GPIO_MODE_OUTPUT_0:
 192       // Set the corresponding direction bit to HIGH for output
 193       MmioOr8 (PL061_GPIO_DIR_REG, GPIO_PIN_MASK(Gpio));
 194       // Set the corresponding data bit to LOW for 0
 195       PL061SetPins (PL061_GPIO_DATA_REG, GPIO_PIN_MASK(Gpio), 0);
 196       break;
 197
 198     case GPIO_MODE_OUTPUT_1:
 199       // Set the corresponding direction bit to HIGH for output
 200       MmioOr8 (PL061_GPIO_DIR_REG, GPIO_PIN_MASK(Gpio));
 201       // Set the corresponding data bit to HIGH for 1
 202       PL061SetPins (PL061_GPIO_DATA_REG, GPIO_PIN_MASK(Gpio), 0xff);
 203     break;
 204
 205     default:
 206       // Other modes are not supported
 207       return EFI_UNSUPPORTED;
 208   }
 209
 210 EXIT:
 211   return Status;
 212 }
 213
 214 /**
 215
 216 Routine Description:
 217
 218   Gets the mode (function) of a GPIO pin
 219
 220 Arguments:
 221
 222   This  - pointer to protocol
 223   Gpio  - which pin
 224   Mode  - pointer to output mode value
 225
 226 Returns:
 227
 228   EFI_SUCCESS           - mode value retrieved
 229   EFI_INVALID_PARAMETER - Mode is a null pointer or Gpio pin is out of range
 230
 231 **/
 232 EFI_STATUS
 233 EFIAPI
 234 GetMode (
 235   IN  EMBEDDED_GPIO       *This,
 236   IN  EMBEDDED_GPIO_PIN   Gpio,
 237   OUT EMBEDDED_GPIO_MODE  *Mode
 238   )
 239 {
 240   // Check for errors
 241   if (    (Mode == NULL)
 242       ||  (Gpio > LAST_GPIO_PIN)) {
 243     return EFI_INVALID_PARAMETER;
 244   }
 245
 246   // Check if it is input or output
 247   if (MmioRead8 (PL061_GPIO_DIR_REG) & GPIO_PIN_MASK(Gpio)) {
 248     // Pin set to output
 249     if (PL061GetPins (PL061_GPIO_DATA_REG, GPIO_PIN_MASK(Gpio))) {
 250       *Mode = GPIO_MODE_OUTPUT_1;
 251     } else {
 252       *Mode = GPIO_MODE_OUTPUT_0;
 253     }
 254   } else {
 255     // Pin set to input
 256     *Mode = GPIO_MODE_INPUT;
 257   }
 258
 259   return EFI_SUCCESS;
 260 }
 261
 262 /**
 263
 264 Routine Description:
 265
 266   Sets the pull-up / pull-down resistor of a GPIO pin
 267
 268 Arguments:
 269
 270   This  - pointer to protocol
 271   Gpio  - which pin
 272   Direction - pull-up, pull-down, or none
 273
 274 Returns:
 275
 276   EFI_UNSUPPORTED - Can not perform the requested operation
 277
 278 **/
 279 EFI_STATUS
 280 EFIAPI
 281 SetPull (
 282   IN  EMBEDDED_GPIO       *This,
 283   IN  EMBEDDED_GPIO_PIN   Gpio,
 284   IN  EMBEDDED_GPIO_PULL  Direction
 285   )
 286 {
 287   return EFI_UNSUPPORTED;
 288 }
 289
 290 /**
 291  Protocol variable definition
 292  **/
 293 EMBEDDED_GPIO gGpio = {
 294   Get,
 295   Set,
 296   GetMode,
 297   SetPull
 298 };
 299
 300 /**
 301   Initialize the state information for the Embedded Gpio protocol.
 302
 303   @param  ImageHandle   of the loaded driver
 304   @param  SystemTable   Pointer to the System Table
 305
 306   @retval EFI_SUCCESS           Protocol registered
 307   @retval EFI_OUT_OF_RESOURCES  Cannot allocate protocol data structure
 308   @retval EFI_DEVICE_ERROR      Hardware problems
 309
 310 **/
 311 EFI_STATUS
 312 EFIAPI
 313 PL061InstallProtocol (
 314   IN EFI_HANDLE         ImageHandle,
 315   IN EFI_SYSTEM_TABLE   *SystemTable
 316   )
 317 {
 318   EFI_STATUS  Status;
 319   EFI_HANDLE  Handle;
 320
 321   //
 322   // Make sure the Gpio protocol has not been installed in the system yet.
 323   //
 324   ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEmbeddedGpioProtocolGuid);
 325
 326   Status = PL061Identify();
 327   if (EFI_ERROR(Status)) {
 328     return EFI_DEVICE_ERROR;
 329   }
 330
 331   // Install the Embedded GPIO Protocol onto a new handle
 332   Handle = NULL;
 333   Status = gBS->InstallMultipleProtocolInterfaces(
 334                   &Handle,
 335                   &gEmbeddedGpioProtocolGuid, &gGpio,
 336                   NULL
 337                  );
 338   if (EFI_ERROR(Status)) {
 339     Status = EFI_OUT_OF_RESOURCES;
 340   }
 341
 342   return Status;
 343 }