cpu/blackfin/serial.h

   1 /*
   2  * serial.h - common serial defines for early debug and serial driver.
   3  *            any functions defined here must be always_inline since
   4  *            initcode cannot have function calls.
   5  *
   6  * Copyright (c) 2004-2007 Analog Devices Inc.
   7  *
   8  * Licensed under the GPL-2 or later.
   9  */
  10
  11 #ifndef __BFIN_CPU_SERIAL_H__
  12 #define __BFIN_CPU_SERIAL_H__
  13
  14 #include <asm/blackfin.h>
  15 #include <asm/mach-common/bits/uart.h>
  16
  17 #ifdef CONFIG_DEBUG_EARLY_SERIAL
  18 # define BFIN_DEBUG_EARLY_SERIAL 1
  19 #else
  20 # define BFIN_DEBUG_EARLY_SERIAL 0
  21 #endif
  22
  23 #define LOB(x) ((x) & 0xFF)
  24 #define HIB(x) (((x) >> 8) & 0xFF)
  25
  26 #ifndef UART_LSR
  27 # if (CONFIG_UART_CONSOLE == 3)
  28 #  define pUART_DLH  pUART3_DLH
  29 #  define pUART_DLL  pUART3_DLL
  30 #  define pUART_GCTL pUART3_GCTL
  31 #  define pUART_IER  pUART3_IER
  32 #  define pUART_IERC pUART3_IER_CLEAR
  33 #  define pUART_LCR  pUART3_LCR
  34 #  define pUART_LSR  pUART3_LSR
  35 #  define pUART_RBR  pUART3_RBR
  36 #  define pUART_THR  pUART3_THR
  37 #  define  UART_THR   UART3_THR
  38 #  define  UART_LSR   UART3_LSR
  39 # elif (CONFIG_UART_CONSOLE == 2)
  40 #  define pUART_DLH  pUART2_DLH
  41 #  define pUART_DLL  pUART2_DLL
  42 #  define pUART_GCTL pUART2_GCTL
  43 #  define pUART_IER  pUART2_IER
  44 #  define pUART_IERC pUART2_IER_CLEAR
  45 #  define pUART_LCR  pUART2_LCR
  46 #  define pUART_LSR  pUART2_LSR
  47 #  define pUART_RBR  pUART2_RBR
  48 #  define pUART_THR  pUART2_THR
  49 #  define  UART_THR   UART2_THR
  50 #  define  UART_LSR   UART2_LSR
  51 # elif (CONFIG_UART_CONSOLE == 1)
  52 #  define pUART_DLH  pUART1_DLH
  53 #  define pUART_DLL  pUART1_DLL
  54 #  define pUART_GCTL pUART1_GCTL
  55 #  define pUART_IER  pUART1_IER
  56 #  define pUART_IERC pUART1_IER_CLEAR
  57 #  define pUART_LCR  pUART1_LCR
  58 #  define pUART_LSR  pUART1_LSR
  59 #  define pUART_RBR  pUART1_RBR
  60 #  define pUART_THR  pUART1_THR
  61 #  define  UART_THR   UART1_THR
  62 #  define  UART_LSR   UART1_LSR
  63 # elif (CONFIG_UART_CONSOLE == 0)
  64 #  define pUART_DLH  pUART0_DLH
  65 #  define pUART_DLL  pUART0_DLL
  66 #  define pUART_GCTL pUART0_GCTL
  67 #  define pUART_IER  pUART0_IER
  68 #  define pUART_IERC pUART0_IER_CLEAR
  69 #  define pUART_LCR  pUART0_LCR
  70 #  define pUART_LSR  pUART0_LSR
  71 #  define pUART_RBR  pUART0_RBR
  72 #  define pUART_THR  pUART0_THR
  73 #  define  UART_THR   UART0_THR
  74 #  define  UART_LSR   UART0_LSR
  75 # endif
  76 #endif
  77
  78 #ifndef __ASSEMBLY__
  79
  80 /* We cannot use get_sclk() in initcode as it is defined elsewhere. */
  81 #ifdef BFIN_IN_INITCODE
  82 # define get_sclk() (CONFIG_CLKIN_HZ * CONFIG_VCO_MULT / CONFIG_SCLK_DIV)
  83 #endif
  84
  85 #ifdef __ADSPBF54x__
  86 # define ACCESS_LATCH()
  87 # define ACCESS_PORT_IER()
  88 # define CLEAR_IER()       (*pUART_IERC = 0)
  89 #else
  90 # define ACCESS_LATCH()    (*pUART_LCR |= DLAB)
  91 # define ACCESS_PORT_IER() (*pUART_LCR &= ~DLAB)
  92 # define CLEAR_IER()       (*pUART_IER = 0)
  93 #endif
  94
  95 __attribute__((always_inline))
  96 static inline void serial_do_portmux(void)
  97 {
  98 #ifdef __ADSPBF52x__
  99 # define DO_MUX(port, mux, tx, rx) \
 100         bfin_write_PORT##port##_MUX((bfin_read_PORT##port##_MUX() & ~PORT_x_MUX_##mux##_MASK) | PORT_x_MUX_##mux##_FUNC_3); \
 101         bfin_write_PORT##port##_FER(bfin_read_PORT##port##_FER() | P##port##tx | P##port##rx);
 102         switch (CONFIG_UART_CONSOLE) {
 103         case 0: DO_MUX(G, 2, 7, 8);   break;    /* Port G; mux 2; PG2 and PG8 */
 104         case 1: DO_MUX(F, 5, 14, 15); break;    /* Port F; mux 5; PF14 and PF15 */
 105         }
 106         SSYNC();
 107 #elif defined(__ADSPBF537__) || defined(__ADSPBF536__) || defined(__ADSPBF534__)
 108 # define DO_MUX(func, tx, rx) \
 109         bfin_write_PORT_MUX(bfin_read_PORT_MUX() & ~(func)); \
 110         bfin_write_PORTF_FER(bfin_read_PORTF_FER() | PF##tx | PF##rx);
 111         switch (CONFIG_UART_CONSOLE) {
 112         case 0: DO_MUX(PFDE, 0, 1); break;
 113         case 1: DO_MUX(PFTE, 2, 3); break;
 114         }
 115         SSYNC();
 116 #elif defined(__ADSPBF54x__)
 117 # define DO_MUX(port, tx, rx) \
 118         bfin_write_PORT##port##_MUX((bfin_read_PORT##port##_MUX() & ~(PORT_x_MUX_##tx##_MASK | PORT_x_MUX_##rx##_MASK)) | PORT_x_MUX_##tx##_FUNC_1 | PORT_x_MUX_##rx##_FUNC_1); \
 119         bfin_write_PORT##port##_FER(bfin_read_PORT##port##_FER() | P##port##tx | P##port##rx);
 120         switch (CONFIG_UART_CONSOLE) {
 121         case 0: DO_MUX(E, 7, 8); break; /* Port E; PE7 and PE8 */
 122         case 1: DO_MUX(H, 0, 1); break; /* Port H; PH0 and PH1 */
 123         case 2: DO_MUX(B, 4, 5); break; /* Port B; PB4 and PB5 */
 124         case 3: DO_MUX(B, 6, 7); break; /* Port B; PB6 and PB7 */
 125         }
 126         SSYNC();
 127 #endif
 128 }
 129
 130 __attribute__((always_inline))
 131 static inline void serial_early_init(void)
 132 {
 133         /* handle portmux crap on different Blackfins */
 134         serial_do_portmux();
 135
 136         /* Enable UART */
 137         *pUART_GCTL = UCEN;
 138
 139         /* Set LCR to Word Lengh 8-bit word select */
 140         *pUART_LCR = WLS_8;
 141
 142         SSYNC();
 143 }
 144
 145 __attribute__((always_inline))
 146 static inline uint32_t serial_early_get_baud(void)
 147 {
 148         /* If the UART isnt enabled, then we are booting an LDR
 149          * from a non-UART source (so like flash) which means
 150          * the baud rate here is meaningless.
 151          */
 152         if ((*pUART_GCTL & UCEN) != UCEN)
 153                 return 0;
 154
 155 #if (0) /* See comment for serial_reset_baud() in initcode.c */
 156         /* Set DLAB in LCR to Access DLL and DLH */
 157         ACCESS_LATCH();
 158         SSYNC();
 159
 160         uint8_t dll = *pUART_DLL;
 161         uint8_t dlh = *pUART_DLH;
 162         uint16_t divisor = (dlh << 8) | dll;
 163         uint32_t baud = get_sclk() / (divisor * 16);
 164
 165         /* Clear DLAB in LCR to Access THR RBR IER */
 166         ACCESS_PORT_IER();
 167         SSYNC();
 168
 169         return baud;
 170 #else
 171         return CONFIG_BAUDRATE;
 172 #endif
 173 }
 174
 175 __attribute__((always_inline))
 176 static inline void serial_early_set_baud(uint32_t baud)
 177 {
 178         /* Translate from baud into divisor in terms of SCLK.
 179          * The +1 is to make sure we over sample just a little
 180          * rather than under sample the incoming signals.
 181          */
 182         uint16_t divisor = (get_sclk() / (baud * 16)) + 1;
 183
 184         /* Set DLAB in LCR to Access DLL and DLH */
 185         ACCESS_LATCH();
 186         SSYNC();
 187
 188         /* Program the divisor to get the baud rate we want */
 189         *pUART_DLL = LOB(divisor);
 190         *pUART_DLH = HIB(divisor);
 191         SSYNC();
 192
 193         /* Clear DLAB in LCR to Access THR RBR IER */
 194         ACCESS_PORT_IER();
 195         SSYNC();
 196 }
 197
 198 #ifndef BFIN_IN_INITCODE
 199 __attribute__((always_inline))
 200 static inline void serial_early_puts(const char *s)
 201 {
 202         if (BFIN_DEBUG_EARLY_SERIAL) {
 203                 serial_puts("Early: ");
 204                 serial_puts(s);
 205         }
 206 }
 207 #endif
 208
 209 #else
 210
 211 .macro serial_early_init
 212 #ifdef CONFIG_DEBUG_EARLY_SERIAL
 213         call _serial_initialize;
 214 #endif
 215 .endm
 216
 217 .macro serial_early_set_baud
 218 #ifdef CONFIG_DEBUG_EARLY_SERIAL
 219         R0.L = LO(CONFIG_BAUDRATE);
 220         R0.H = HI(CONFIG_BAUDRATE);
 221         call _serial_set_baud;
 222 #endif
 223 .endm
 224
 225 /* Recursively expand calls to _serial_putc for every byte
 226  * passed to us.  Append a newline when we're all done.
 227  */
 228 .macro _serial_early_putc byte:req morebytes:vararg
 229 #ifdef CONFIG_DEBUG_EARLY_SERIAL
 230         R0 = \byte;
 231         call _serial_putc;
 232 .ifnb \morebytes
 233         _serial_early_putc \morebytes
 234 .else
 235 .if (\byte != '\n')
 236         _serial_early_putc '\n'
 237 .endif
 238 .endif
 239 #endif
 240 .endm
 241
 242 /* Wrapper around recurisve _serial_early_putc macro which
 243  * simply prepends the string "Early: "
 244  */
 245 .macro serial_early_putc byte:req morebytes:vararg
 246 #ifdef CONFIG_DEBUG_EARLY_SERIAL
 247         _serial_early_putc 'E', 'a', 'r', 'l', 'y', ':', ' ', \byte, \morebytes
 248 #endif
 249 .endm
 250
 251 /* Since we embed the string right into our .text section, we need
 252  * to find its address.  We do this by getting our PC and adding 2
 253  * bytes (which is the length of the jump instruction).  Then we
 254  * pass this address to serial_puts().
 255  */
 256 #ifdef CONFIG_DEBUG_EARLY_SERIAL
 257 # define serial_early_puts(str) \
 258         call _get_pc; \
 259         jump 1f; \
 260         .ascii "Early:"; \
 261         .ascii __FILE__; \
 262         .ascii ": "; \
 263         .ascii str; \
 264         .asciz "\n"; \
 265         .align 4; \
 266 1: \
 267         R0 += 2; \
 268         call _serial_puts;
 269 #else
 270 # define serial_early_puts(str)
 271 #endif
 272
 273 #endif
 274
 275 #endif