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      1 /*
      2  * Copyright (C) 2011, 2012 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef ANDROID_NFC_HAL_INTERFACE_H
     18 #define ANDROID_NFC_HAL_INTERFACE_H
     19 
     20 #include <stdint.h>
     21 #include <strings.h>
     22 #include <sys/cdefs.h>
     23 #include <sys/types.h>
     24 
     25 #include <hardware/hardware.h>
     26 
     27 __BEGIN_DECLS
     28 
     29 
     30 /* NFC device HAL for NCI-based NFC controllers.
     31  *
     32  * This HAL allows NCI silicon vendors to make use
     33  * of the core NCI stack in Android for their own silicon.
     34  *
     35  * The responibilities of the NCI HAL implementation
     36  * are as follows:
     37  *
     38  * - Implement the transport to the NFC controller
     39  * - Implement each of the HAL methods specified below as applicable to their silicon
     40  * - Pass up received NCI messages from the controller to the stack
     41  *
     42  * A simplified timeline of NCI HAL method calls:
     43  * 1) Core NCI stack calls open()
     44  * 2) Core NCI stack executes CORE_RESET and CORE_INIT through calls to write()
     45  * 3) Core NCI stack calls core_initialized() to allow HAL to do post-init configuration
     46  * 4) Core NCI stack calls pre_discover() to allow HAL to prepare for RF discovery
     47  * 5) Core NCI stack starts discovery through calls to write()
     48  * 6) Core NCI stack stops discovery through calls to write() (e.g. screen turns off)
     49  * 7) Core NCI stack calls pre_discover() to prepare for RF discovery (e.g. screen turned back on)
     50  * 8) Core NCI stack starts discovery through calls to write()
     51  * ...
     52  * ...
     53  * 9) Core NCI stack calls close()
     54  */
     55 #define NFC_NCI_HARDWARE_MODULE_ID "nfc_nci"
     56 #define NFC_NCI_CONTROLLER "nci"
     57 
     58 /*
     59  *  nfc_nci_module_t should contain module-specific parameters
     60  */
     61 typedef struct nfc_nci_module_t {
     62     struct hw_module_t common;
     63 } nfc_nci_module_t;
     64 
     65 /*
     66  * HAL events that can be passed back to the stack
     67  */
     68 typedef uint8_t nfc_event_t;
     69 
     70 enum {
     71     HAL_NFC_OPEN_CPLT_EVT           = 0x00,
     72     HAL_NFC_CLOSE_CPLT_EVT          = 0x01,
     73     HAL_NFC_POST_INIT_CPLT_EVT      = 0x02,
     74     HAL_NFC_PRE_DISCOVER_CPLT_EVT   = 0x03,
     75     HAL_NFC_REQUEST_CONTROL_EVT     = 0x04,
     76     HAL_NFC_RELEASE_CONTROL_EVT     = 0x05,
     77     HAL_NFC_ERROR_EVT               = 0x06
     78 };
     79 
     80 /*
     81  * Allowed status return values for each of the HAL methods
     82  */
     83 typedef uint8_t nfc_status_t;
     84 
     85 enum {
     86     HAL_NFC_STATUS_OK               = 0x00,
     87     HAL_NFC_STATUS_FAILED           = 0x01,
     88     HAL_NFC_STATUS_ERR_TRANSPORT    = 0x02,
     89     HAL_NFC_STATUS_ERR_CMD_TIMEOUT  = 0x03,
     90     HAL_NFC_STATUS_REFUSED          = 0x04
     91 };
     92 
     93 /*
     94  * The callback passed in from the NFC stack that the HAL
     95  * can use to pass events back to the stack.
     96  */
     97 typedef void (nfc_stack_callback_t) (nfc_event_t event, nfc_status_t event_status);
     98 
     99 /*
    100  * The callback passed in from the NFC stack that the HAL
    101  * can use to pass incomming data to the stack.
    102  */
    103 typedef void (nfc_stack_data_callback_t) (uint16_t data_len, uint8_t* p_data);
    104 
    105 /* nfc_nci_device_t starts with a hw_device_t struct,
    106  * followed by device-specific methods and members.
    107  *
    108  * All methods in the NCI HAL are asynchronous.
    109  */
    110 typedef struct nfc_nci_device {
    111     struct hw_device_t common;
    112     /*
    113      * (*open)() Opens the NFC controller device and performs initialization.
    114      * This may include patch download and other vendor-specific initialization.
    115      *
    116      * If open completes successfully, the controller should be ready to perform
    117      * NCI initialization - ie accept CORE_RESET and subsequent commands through
    118      * the write() call.
    119      *
    120      * If open() returns 0, the NCI stack will wait for a HAL_NFC_OPEN_CPLT_EVT
    121      * before continuing.
    122      *
    123      * If open() returns any other value, the NCI stack will stop.
    124      *
    125      */
    126     int (*open)(const struct nfc_nci_device *p_dev, nfc_stack_callback_t *p_cback,
    127             nfc_stack_data_callback_t *p_data_cback);
    128 
    129     /*
    130      * (*write)() Performs an NCI write.
    131      *
    132      * This method may queue writes and return immediately. The only
    133      * requirement is that the writes are executed in order.
    134      */
    135     int (*write)(const struct nfc_nci_device *p_dev, uint16_t data_len, const uint8_t *p_data);
    136 
    137     /*
    138      * (*core_initialized)() is called after the CORE_INIT_RSP is received from the NFCC.
    139      * At this time, the HAL can do any chip-specific configuration.
    140      *
    141      * If core_initialized() returns 0, the NCI stack will wait for a HAL_NFC_POST_INIT_CPLT_EVT
    142      * before continuing.
    143      *
    144      * If core_initialized() returns any other value, the NCI stack will continue
    145      * immediately.
    146      */
    147     int (*core_initialized)(const struct nfc_nci_device *p_dev, uint8_t* p_core_init_rsp_params);
    148 
    149     /*
    150      * (*pre_discover)() Is called every time before starting RF discovery.
    151      * It is a good place to do vendor-specific configuration that must be
    152      * performed every time RF discovery is about to be started.
    153      *
    154      * If pre_discover() returns 0, the NCI stack will wait for a HAL_NFC_PRE_DISCOVER_CPLT_EVT
    155      * before continuing.
    156      *
    157      * If pre_discover() returns any other value, the NCI stack will start
    158      * RF discovery immediately.
    159      */
    160     int (*pre_discover)(const struct nfc_nci_device *p_dev);
    161 
    162     /*
    163      * (*close)() Closed the NFC controller. Should free all resources.
    164      */
    165     int (*close)(const struct nfc_nci_device *p_dev);
    166 
    167     /*
    168      * (*control_granted)() Grant HAL the exclusive control to send NCI commands.
    169      * Called in response to HAL_REQUEST_CONTROL_EVT.
    170      * Must only be called when there are no NCI commands pending.
    171      * HAL_RELEASE_CONTROL_EVT will notify when HAL no longer needs exclusive control.
    172      */
    173     int (*control_granted)(const struct nfc_nci_device *p_dev);
    174 
    175     /*
    176      * (*power_cycle)() Restart controller by power cyle;
    177      * HAL_OPEN_CPLT_EVT will notify when operation is complete.
    178      */
    179     int (*power_cycle)(const struct nfc_nci_device *p_dev);
    180 } nfc_nci_device_t;
    181 
    182 /*
    183  * Convenience methods that the NFC stack can use to open
    184  * and close an NCI device
    185  */
    186 static inline int nfc_nci_open(const struct hw_module_t* module,
    187         nfc_nci_device_t** dev) {
    188     return module->methods->open(module, NFC_NCI_CONTROLLER,
    189         (struct hw_device_t**) dev);
    190 }
    191 
    192 static inline int nfc_nci_close(nfc_nci_device_t* dev) {
    193     return dev->common.close(&dev->common);
    194 }
    195 /*
    196  * End NFC NCI HAL
    197  */
    198 
    199 /*
    200  * This is a limited NFC HAL for NXP PN544-based devices.
    201  * This HAL as Android is moving to
    202  * an NCI-based NFC stack.
    203  *
    204  * All NCI-based NFC controllers should use the NFC-NCI
    205  * HAL instead.
    206  * Begin PN544 specific HAL
    207  */
    208 #define NFC_HARDWARE_MODULE_ID "nfc"
    209 
    210 #define NFC_PN544_CONTROLLER "pn544"
    211 
    212 typedef struct nfc_module_t {
    213     struct hw_module_t common;
    214 } nfc_module_t;
    215 
    216 /*
    217  * PN544 linktypes.
    218  * UART
    219  * I2C
    220  * USB (uses UART DAL)
    221  */
    222 typedef enum {
    223     PN544_LINK_TYPE_UART,
    224     PN544_LINK_TYPE_I2C,
    225     PN544_LINK_TYPE_USB,
    226     PN544_LINK_TYPE_INVALID,
    227 } nfc_pn544_linktype;
    228 
    229 typedef struct {
    230     struct hw_device_t common;
    231 
    232     /* The number of EEPROM registers to write */
    233     uint32_t num_eeprom_settings;
    234 
    235     /* The actual EEPROM settings
    236      * For PN544, each EEPROM setting is a 4-byte entry,
    237      * of the format [0x00, addr_msb, addr_lsb, value].
    238      */
    239     uint8_t* eeprom_settings;
    240 
    241     /* The link type to which the PN544 is connected */
    242     nfc_pn544_linktype linktype;
    243 
    244     /* The device node to which the PN544 is connected */
    245     const char* device_node;
    246 
    247     /* On Crespo we had an I2C issue that would cause us to sometimes read
    248      * the I2C slave address (0x57) over the bus. libnfc contains
    249      * a hack to ignore this byte and try to read the length byte
    250      * again.
    251      * Set to 0 to disable the workaround, 1 to enable it.
    252      */
    253     uint8_t enable_i2c_workaround;
    254     /* I2C slave address. Multiple I2C addresses are
    255      * possible for PN544 module. Configure address according to
    256      * board design.
    257      */
    258     uint8_t i2c_device_address;
    259 } nfc_pn544_device_t;
    260 
    261 static inline int nfc_pn544_open(const struct hw_module_t* module,
    262         nfc_pn544_device_t** dev) {
    263     return module->methods->open(module, NFC_PN544_CONTROLLER,
    264         (struct hw_device_t**) dev);
    265 }
    266 
    267 static inline int nfc_pn544_close(nfc_pn544_device_t* dev) {
    268     return dev->common.close(&dev->common);
    269 }
    270 /*
    271  * End PN544 specific HAL
    272  */
    273 
    274 __END_DECLS
    275 
    276 #endif // ANDROID_NFC_HAL_INTERFACE_H
    277