arch/blackfin/cpu/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 #ifndef CONFIG_UART_CONSOLE
  18 # define CONFIG_UART_CONSOLE 0
  19 #endif
  20
  21 #ifdef CONFIG_DEBUG_EARLY_SERIAL
  22 # define BFIN_DEBUG_EARLY_SERIAL 1
  23 #else
  24 # define BFIN_DEBUG_EARLY_SERIAL 0
  25 #endif
  26
  27 #ifndef __ASSEMBLY__
  28
  29 #define LOB(x) ((x) & 0xFF)
  30 #define HIB(x) (((x) >> 8) & 0xFF)
  31
  32 /*
  33  * All Blackfin system MMRs are padded to 32bits even if the register
  34  * itself is only 16bits.  So use a helper macro to streamline this.
  35  */
  36 #define __BFP(m) u16 m; u16 __pad_##m
  37 struct bfin_mmr_serial {
  38 #ifdef __ADSPBF54x__
  39         __BFP(dll);
  40         __BFP(dlh);
  41         __BFP(gctl);
  42         __BFP(lcr);
  43         __BFP(mcr);
  44         __BFP(lsr);
  45         __BFP(msr);
  46         __BFP(scr);
  47         __BFP(ier_set);
  48         __BFP(ier_clear);
  49         __BFP(thr);
  50         __BFP(rbr);
  51 #else
  52         union {
  53                 u16 dll;
  54                 u16 thr;
  55                 const u16 rbr;
  56         };
  57         const u16 __spad0;
  58         union {
  59                 u16 dlh;
  60                 u16 ier;
  61         };
  62         const u16 __spad1;
  63         const __BFP(iir);
  64         __BFP(lcr);
  65         __BFP(mcr);
  66         __BFP(lsr);
  67         __BFP(msr);
  68         __BFP(scr);
  69         const u32 __spad2;
  70         __BFP(gctl);
  71 #endif
  72 };
  73 #undef __BFP
  74
  75 #ifndef UART_LSR
  76 # if (CONFIG_UART_CONSOLE == 3)
  77 #  define UART_BASE UART3_DLL
  78 # elif (CONFIG_UART_CONSOLE == 2)
  79 #  define UART_BASE UART2_DLL
  80 # elif (CONFIG_UART_CONSOLE == 1)
  81 #  define UART_BASE UART1_DLL
  82 # elif (CONFIG_UART_CONSOLE == 0)
  83 #  define UART_BASE UART0_DLL
  84 # endif
  85 #else
  86 # if CONFIG_UART_CONSOLE != 0
  87 #  error CONFIG_UART_CONSOLE must be 0 on parts with only one UART
  88 # endif
  89 # define UART_BASE UART_DLL
  90 #endif
  91 #define pUART ((volatile struct bfin_mmr_serial *)UART_BASE)
  92
  93 #ifdef __ADSPBF54x__
  94 # define ACCESS_LATCH()
  95 # define ACCESS_PORT_IER()
  96 #else
  97 # define ACCESS_LATCH() \
  98         bfin_write16(&pUART->lcr, bfin_read16(&pUART->lcr) | DLAB)
  99 # define ACCESS_PORT_IER() \
 100         bfin_write16(&pUART->lcr, bfin_read16(&pUART->lcr) & ~DLAB)
 101 #endif
 102
 103 __attribute__((always_inline))
 104 static inline void serial_do_portmux(void)
 105 {
 106 #if defined(__ADSPBF51x__)
 107 # define DO_MUX(port, mux_tx, mux_rx, tx, rx) \
 108         bfin_write_PORT##port##_MUX((bfin_read_PORT##port##_MUX() & ~(PORT_x_MUX_##mux_tx##_MASK | PORT_x_MUX_##mux_rx##_MASK)) | PORT_x_MUX_##mux_tx##_FUNC_2 | PORT_x_MUX_##mux_rx##_FUNC_2); \
 109         bfin_write_PORT##port##_FER(bfin_read_PORT##port##_FER() | P##port##tx | P##port##rx);
 110         switch (CONFIG_UART_CONSOLE) {
 111         case 0: DO_MUX(G, 5, 5, 9, 10);  break; /* Port G; mux 5; PG9 and PG10 */
 112         case 1: DO_MUX(F, 2, 3, 14, 15); break; /* Port H; mux 2/3; PH14 and PH15 */
 113         }
 114         SSYNC();
 115 #elif defined(__ADSPBF52x__)
 116 # define DO_MUX(port, mux, tx, rx) \
 117         bfin_write_PORT##port##_MUX((bfin_read_PORT##port##_MUX() & ~PORT_x_MUX_##mux##_MASK) | PORT_x_MUX_##mux##_FUNC_3); \
 118         bfin_write_PORT##port##_FER(bfin_read_PORT##port##_FER() | P##port##tx | P##port##rx);
 119         switch (CONFIG_UART_CONSOLE) {
 120         case 0: DO_MUX(G, 2, 7, 8);   break;    /* Port G; mux 2; PG2 and PG8 */
 121         case 1: DO_MUX(F, 5, 14, 15); break;    /* Port F; mux 5; PF14 and PF15 */
 122         }
 123         SSYNC();
 124 #elif defined(__ADSPBF537__) || defined(__ADSPBF536__) || defined(__ADSPBF534__)
 125 # define DO_MUX(func, tx, rx) \
 126         bfin_write_PORT_MUX(bfin_read_PORT_MUX() & ~(func)); \
 127         bfin_write_PORTF_FER(bfin_read_PORTF_FER() | PF##tx | PF##rx);
 128         switch (CONFIG_UART_CONSOLE) {
 129         case 0: DO_MUX(PFDE, 0, 1); break;
 130         case 1: DO_MUX(PFTE, 2, 3); break;
 131         }
 132         SSYNC();
 133 #elif defined(__ADSPBF54x__)
 134 # define DO_MUX(port, tx, rx) \
 135         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); \
 136         bfin_write_PORT##port##_FER(bfin_read_PORT##port##_FER() | P##port##tx | P##port##rx);
 137         switch (CONFIG_UART_CONSOLE) {
 138         case 0: DO_MUX(E, 7, 8); break; /* Port E; PE7 and PE8 */
 139         case 1: DO_MUX(H, 0, 1); break; /* Port H; PH0 and PH1 */
 140         case 2: DO_MUX(B, 4, 5); break; /* Port B; PB4 and PB5 */
 141         case 3: DO_MUX(B, 6, 7); break; /* Port B; PB6 and PB7 */
 142         }
 143         SSYNC();
 144 #endif
 145 }
 146
 147 __attribute__((always_inline))
 148 static inline void serial_early_init(void)
 149 {
 150         /* handle portmux crap on different Blackfins */
 151         serial_do_portmux();
 152
 153         /* always enable UART -- avoids anomalies 05000309 and 05000350 */
 154         bfin_write16(&pUART->gctl, UCEN);
 155
 156         /* Set LCR to Word Lengh 8-bit word select */
 157         bfin_write16(&pUART->lcr, WLS_8);
 158
 159         SSYNC();
 160 }
 161
 162 __attribute__((always_inline))
 163 static inline void serial_early_put_div(uint16_t divisor)
 164 {
 165         /* Set DLAB in LCR to Access DLL and DLH */
 166         ACCESS_LATCH();
 167         SSYNC();
 168
 169         /* Program the divisor to get the baud rate we want */
 170         bfin_write16(&pUART->dll, LOB(divisor));
 171         bfin_write16(&pUART->dlh, HIB(divisor));
 172         SSYNC();
 173
 174         /* Clear DLAB in LCR to Access THR RBR IER */
 175         ACCESS_PORT_IER();
 176         SSYNC();
 177 }
 178
 179 __attribute__((always_inline))
 180 static inline uint16_t serial_early_get_div(void)
 181 {
 182         /* Set DLAB in LCR to Access DLL and DLH */
 183         ACCESS_LATCH();
 184         SSYNC();
 185
 186         uint8_t dll = bfin_read16(&pUART->dll);
 187         uint8_t dlh = bfin_read16(&pUART->dlh);
 188         uint16_t divisor = (dlh << 8) | dll;
 189
 190         /* Clear DLAB in LCR to Access THR RBR IER */
 191         ACCESS_PORT_IER();
 192         SSYNC();
 193
 194         return divisor;
 195 }
 196
 197 /* We cannot use get_sclk() early on as it uses caches in external memory */
 198 #if defined(BFIN_IN_INITCODE) || defined(CONFIG_DEBUG_EARLY_SERIAL)
 199 # define get_sclk() (CONFIG_CLKIN_HZ * CONFIG_VCO_MULT / CONFIG_SCLK_DIV)
 200 #endif
 201
 202 __attribute__((always_inline))
 203 static inline void serial_early_set_baud(uint32_t baud)
 204 {
 205         /* Translate from baud into divisor in terms of SCLK.  The
 206          * weird multiplication is to make sure we over sample just
 207          * a little rather than under sample the incoming signals.
 208          */
 209         serial_early_put_div((get_sclk() + (baud * 8)) / (baud * 16) - ANOMALY_05000230);
 210 }
 211
 212 #ifndef BFIN_IN_INITCODE
 213 __attribute__((always_inline))
 214 static inline void serial_early_puts(const char *s)
 215 {
 216         if (BFIN_DEBUG_EARLY_SERIAL) {
 217                 serial_puts("Early: ");
 218                 serial_puts(s);
 219         }
 220 }
 221 #endif
 222
 223 #else
 224
 225 .macro serial_early_init
 226 #ifdef CONFIG_DEBUG_EARLY_SERIAL
 227         call _serial_initialize;
 228 #endif
 229 .endm
 230
 231 .macro serial_early_set_baud
 232 #ifdef CONFIG_DEBUG_EARLY_SERIAL
 233         R0.L = LO(CONFIG_BAUDRATE);
 234         R0.H = HI(CONFIG_BAUDRATE);
 235         call _serial_set_baud;
 236 #endif
 237 .endm
 238
 239 /* Since we embed the string right into our .text section, we need
 240  * to find its address.  We do this by getting our PC and adding 2
 241  * bytes (which is the length of the jump instruction).  Then we
 242  * pass this address to serial_puts().
 243  */
 244 #ifdef CONFIG_DEBUG_EARLY_SERIAL
 245 # define serial_early_puts(str) \
 246         call _get_pc; \
 247         jump 1f; \
 248         .ascii "Early:"; \
 249         .ascii __FILE__; \
 250         .ascii ": "; \
 251         .ascii str; \
 252         .asciz "\n"; \
 253         .align 4; \
 254 1: \
 255         R0 += 2; \
 256         call _serial_puts;
 257 #else
 258 # define serial_early_puts(str)
 259 #endif
 260
 261 #endif
 262
 263 #endif