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 #include <asm/portmux.h>
  30
  31 #define LOB(x) ((x) & 0xFF)
  32 #define HIB(x) (((x) >> 8) & 0xFF)
  33
  34 /*
  35  * All Blackfin system MMRs are padded to 32bits even if the register
  36  * itself is only 16bits.  So use a helper macro to streamline this.
  37  */
  38 #define __BFP(m) u16 m; u16 __pad_##m
  39 struct bfin_mmr_serial {
  40 #ifdef __ADSPBF54x__
  41         __BFP(dll);
  42         __BFP(dlh);
  43         __BFP(gctl);
  44         __BFP(lcr);
  45         __BFP(mcr);
  46         __BFP(lsr);
  47         __BFP(msr);
  48         __BFP(scr);
  49         __BFP(ier_set);
  50         __BFP(ier_clear);
  51         __BFP(thr);
  52         __BFP(rbr);
  53 #else
  54         union {
  55                 u16 dll;
  56                 u16 thr;
  57                 const u16 rbr;
  58         };
  59         const u16 __spad0;
  60         union {
  61                 u16 dlh;
  62                 u16 ier;
  63         };
  64         const u16 __spad1;
  65         const __BFP(iir);
  66         __BFP(lcr);
  67         __BFP(mcr);
  68         __BFP(lsr);
  69         __BFP(msr);
  70         __BFP(scr);
  71         const u32 __spad2;
  72         __BFP(gctl);
  73 #endif
  74 };
  75 #undef __BFP
  76
  77 #ifndef UART_LSR
  78 # if (CONFIG_UART_CONSOLE == 3)
  79 #  define UART_BASE UART3_DLL
  80 # elif (CONFIG_UART_CONSOLE == 2)
  81 #  define UART_BASE UART2_DLL
  82 # elif (CONFIG_UART_CONSOLE == 1)
  83 #  define UART_BASE UART1_DLL
  84 # elif (CONFIG_UART_CONSOLE == 0)
  85 #  define UART_BASE UART0_DLL
  86 # endif
  87 #else
  88 # if CONFIG_UART_CONSOLE != 0
  89 #  error CONFIG_UART_CONSOLE must be 0 on parts with only one UART
  90 # endif
  91 # define UART_BASE UART_DLL
  92 #endif
  93 #define pUART ((volatile struct bfin_mmr_serial *)UART_BASE)
  94
  95 #ifdef __ADSPBF54x__
  96 # define ACCESS_LATCH()
  97 # define ACCESS_PORT_IER()
  98 #else
  99 # define ACCESS_LATCH() \
 100         bfin_write16(&pUART->lcr, bfin_read16(&pUART->lcr) | DLAB)
 101 # define ACCESS_PORT_IER() \
 102         bfin_write16(&pUART->lcr, bfin_read16(&pUART->lcr) & ~DLAB)
 103 #endif
 104
 105 __attribute__((always_inline))
 106 static inline void serial_do_portmux(void)
 107 {
 108         if (!BFIN_DEBUG_EARLY_SERIAL) {
 109                 const unsigned short pins[] = {
 110 #if CONFIG_UART_CONSOLE == 0
 111                         P_UART0_TX, P_UART0_RX,
 112 #elif CONFIG_UART_CONSOLE == 1
 113                         P_UART1_TX, P_UART1_RX,
 114 #elif CONFIG_UART_CONSOLE == 2
 115                         P_UART2_TX, P_UART2_RX,
 116 #elif CONFIG_UART_CONSOLE == 3
 117                         P_UART3_TX, P_UART3_RX,
 118 #endif
 119                         0,
 120                 };
 121                 peripheral_request_list(pins, "bfin-uart");
 122                 return;
 123         }
 124
 125 #if defined(__ADSPBF51x__)
 126 # define DO_MUX(port, mux_tx, mux_rx, tx, rx) \
 127         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); \
 128         bfin_write_PORT##port##_FER(bfin_read_PORT##port##_FER() | P##port##tx | P##port##rx);
 129         switch (CONFIG_UART_CONSOLE) {
 130         case 0: DO_MUX(G, 5, 5, 9, 10);  break; /* Port G; mux 5; PG9 and PG10 */
 131         case 1: DO_MUX(F, 2, 3, 14, 15); break; /* Port H; mux 2/3; PH14 and PH15 */
 132         }
 133         SSYNC();
 134 #elif defined(__ADSPBF52x__)
 135 # define DO_MUX(port, mux, tx, rx) \
 136         bfin_write_PORT##port##_MUX((bfin_read_PORT##port##_MUX() & ~PORT_x_MUX_##mux##_MASK) | PORT_x_MUX_##mux##_FUNC_3); \
 137         bfin_write_PORT##port##_FER(bfin_read_PORT##port##_FER() | P##port##tx | P##port##rx);
 138         switch (CONFIG_UART_CONSOLE) {
 139         case 0: DO_MUX(G, 2, 7, 8);   break;    /* Port G; mux 2; PG2 and PG8 */
 140         case 1: DO_MUX(F, 5, 14, 15); break;    /* Port F; mux 5; PF14 and PF15 */
 141         }
 142         SSYNC();
 143 #elif defined(__ADSPBF537__) || defined(__ADSPBF536__) || defined(__ADSPBF534__)
 144 # define DO_MUX(func, tx, rx) \
 145         bfin_write_PORT_MUX(bfin_read_PORT_MUX() & ~(func)); \
 146         bfin_write_PORTF_FER(bfin_read_PORTF_FER() | PF##tx | PF##rx);
 147         switch (CONFIG_UART_CONSOLE) {
 148         case 0: DO_MUX(PFDE, 0, 1); break;
 149         case 1: DO_MUX(PFTE, 2, 3); break;
 150         }
 151         SSYNC();
 152 #elif defined(__ADSPBF54x__)
 153 # define DO_MUX(port, tx, rx) \
 154         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); \
 155         bfin_write_PORT##port##_FER(bfin_read_PORT##port##_FER() | P##port##tx | P##port##rx);
 156         switch (CONFIG_UART_CONSOLE) {
 157         case 0: DO_MUX(E, 7, 8); break; /* Port E; PE7 and PE8 */
 158         case 1: DO_MUX(H, 0, 1); break; /* Port H; PH0 and PH1 */
 159         case 2: DO_MUX(B, 4, 5); break; /* Port B; PB4 and PB5 */
 160         case 3: DO_MUX(B, 6, 7); break; /* Port B; PB6 and PB7 */
 161         }
 162         SSYNC();
 163 #endif
 164 }
 165
 166 __attribute__((always_inline))
 167 static inline void serial_early_init(void)
 168 {
 169         /* handle portmux crap on different Blackfins */
 170         serial_do_portmux();
 171
 172         /* always enable UART -- avoids anomalies 05000309 and 05000350 */
 173         bfin_write16(&pUART->gctl, UCEN);
 174
 175         /* Set LCR to Word Lengh 8-bit word select */
 176         bfin_write16(&pUART->lcr, WLS_8);
 177
 178         SSYNC();
 179 }
 180
 181 __attribute__((always_inline))
 182 static inline void serial_early_put_div(uint16_t divisor)
 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         bfin_write16(&pUART->dll, LOB(divisor));
 190         bfin_write16(&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 __attribute__((always_inline))
 199 static inline uint16_t serial_early_get_div(void)
 200 {
 201         /* Set DLAB in LCR to Access DLL and DLH */
 202         ACCESS_LATCH();
 203         SSYNC();
 204
 205         uint8_t dll = bfin_read16(&pUART->dll);
 206         uint8_t dlh = bfin_read16(&pUART->dlh);
 207         uint16_t divisor = (dlh << 8) | dll;
 208
 209         /* Clear DLAB in LCR to Access THR RBR IER */
 210         ACCESS_PORT_IER();
 211         SSYNC();
 212
 213         return divisor;
 214 }
 215
 216 /* We cannot use get_sclk() early on as it uses caches in external memory */
 217 #if defined(BFIN_IN_INITCODE) || defined(CONFIG_DEBUG_EARLY_SERIAL)
 218 # define get_sclk() (CONFIG_CLKIN_HZ * CONFIG_VCO_MULT / CONFIG_SCLK_DIV)
 219 #endif
 220
 221 __attribute__((always_inline))
 222 static inline void serial_early_set_baud(uint32_t baud)
 223 {
 224         /* Translate from baud into divisor in terms of SCLK.  The
 225          * weird multiplication is to make sure we over sample just
 226          * a little rather than under sample the incoming signals.
 227          */
 228         serial_early_put_div((get_sclk() + (baud * 8)) / (baud * 16) - ANOMALY_05000230);
 229 }
 230
 231 #ifndef BFIN_IN_INITCODE
 232 __attribute__((always_inline))
 233 static inline void serial_early_puts(const char *s)
 234 {
 235         if (BFIN_DEBUG_EARLY_SERIAL) {
 236                 serial_puts("Early: ");
 237                 serial_puts(s);
 238         }
 239 }
 240 #endif
 241
 242 #else
 243
 244 .macro serial_early_init
 245 #ifdef CONFIG_DEBUG_EARLY_SERIAL
 246         call _serial_initialize;
 247 #endif
 248 .endm
 249
 250 .macro serial_early_set_baud
 251 #ifdef CONFIG_DEBUG_EARLY_SERIAL
 252         R0.L = LO(CONFIG_BAUDRATE);
 253         R0.H = HI(CONFIG_BAUDRATE);
 254         call _serial_set_baud;
 255 #endif
 256 .endm
 257
 258 /* Since we embed the string right into our .text section, we need
 259  * to find its address.  We do this by getting our PC and adding 2
 260  * bytes (which is the length of the jump instruction).  Then we
 261  * pass this address to serial_puts().
 262  */
 263 #ifdef CONFIG_DEBUG_EARLY_SERIAL
 264 # define serial_early_puts(str) \
 265         call _get_pc; \
 266         jump 1f; \
 267         .ascii "Early:"; \
 268         .ascii __FILE__; \
 269         .ascii ": "; \
 270         .ascii str; \
 271         .asciz "\n"; \
 272         .align 4; \
 273 1: \
 274         R0 += 2; \
 275         call _serial_puts;
 276 #else
 277 # define serial_early_puts(str)
 278 #endif
 279
 280 #endif
 281
 282 #endif