form their addresses. That is, log base 2 of the span between
adjacent ns16550 registers in the system.
+config MIPS_CPS_NS16550_WIDTH
+ int "UART Register Width"
+ default 1
+ help
+ ns16550 registers width. UART registers IO access methods will be
+ selected in accordance with this parameter. By setting it to 1, 2 or
+ 4 UART registers will be accessed by means of lb/sb, lh/sh or lw/sw
+ instructions respectively. Any value not from that set activates
+ lb/sb instructions.
+
endif # MIPS_CPS_NS16550_BOOL
#define UART_TX_OFS (UART_TX << CONFIG_MIPS_CPS_NS16550_SHIFT)
#define UART_LSR_OFS (UART_LSR << CONFIG_MIPS_CPS_NS16550_SHIFT)
+#if CONFIG_MIPS_CPS_NS16550_WIDTH == 1
+# define UART_L lb
+# define UART_S sb
+#elif CONFIG_MIPS_CPS_NS16550_WIDTH == 2
+# define UART_L lh
+# define UART_S sh
+#elif CONFIG_MIPS_CPS_NS16550_WIDTH == 4
+# define UART_L lw
+# define UART_S sw
+#else
+# define UART_L lb
+# define UART_S sb
+#endif
+
/**
* _mips_cps_putc() - write a character to the UART
* @a0: ASCII character to write
* @t9: UART base address
*/
LEAF(_mips_cps_putc)
-1: lw t0, UART_LSR_OFS(t9)
+1: UART_L t0, UART_LSR_OFS(t9)
andi t0, t0, UART_LSR_TEMT
beqz t0, 1b
- sb a0, UART_TX_OFS(t9)
+ UART_S a0, UART_TX_OFS(t9)
jr ra
END(_mips_cps_putc)