* Polled-mode 16x50 UART driver.
*/
+#include <machine/machine_routines.h>
#include <pexpert/protos.h>
#include <pexpert/pexpert.h>
-/* standard port addresses */
+struct pe_serial_functions {
+ void (*uart_init) (void);
+ void (*uart_set_baud_rate) (int unit, uint32_t baud_rate);
+ int (*tr0) (void);
+ void (*td0) (int c);
+ int (*rr0) (void);
+ int (*rd0) (void);
+};
+
+static struct pe_serial_functions *gPESF;
+
+static int uart_initted = 0; /* 1 if init'ed */
+
+#define DEFAULT_UART_BAUD_RATE 115200
+
+static unsigned uart_baud_rate = DEFAULT_UART_BAUD_RATE;
+
+// =============================================================================
+// Legacy UART support using IO transactions to COM1 or COM2
+// =============================================================================
+
+#define LEGACY_UART_PORT_ADDR COM1_PORT_ADDR
+#define LEGACY_UART_CLOCK 1843200 /* 1.8432 MHz clock */
+
+#define IO_WRITE(r, v) outb(LEGACY_UART_PORT_ADDR + UART_##r, v)
+#define IO_READ(r) inb(LEGACY_UART_PORT_ADDR + UART_##r)
+
enum {
COM1_PORT_ADDR = 0x3f8,
COM2_PORT_ADDR = 0x2f8
};
-/* UART register offsets */
enum {
UART_RBR = 0, /* receive buffer Register (R) */
UART_THR = 0, /* transmit holding register (W) */
UART_LCR = 3, /* line control register */
UART_MCR = 4, /* modem control register */
UART_LSR = 5, /* line status register */
- UART_MSR = 6 /* modem status register */
+ UART_MSR = 6, /* modem status register */
+ UART_SCR = 7 /* scratch register */
};
enum {
UART_LSR_THRE = 0x20
};
-static unsigned uart_baud_rate = 115200;
-#define UART_PORT_ADDR COM1_PORT_ADDR
-
-#define UART_CLOCK 1843200 /* 1.8432 MHz clock */
-
-#define WRITE(r, v) outb(UART_PORT_ADDR + UART_##r, v)
-#define READ(r) inb(UART_PORT_ADDR + UART_##r)
-#define DELAY(x) { volatile int _d_; for (_d_ = 0; _d_ < (10000*x); _d_++) ; }
-
-static int uart_initted = 0; /* 1 if init'ed */
-
static int
-uart_probe( void )
+legacy_uart_probe( void )
{
- /* Verify that the Divisor Register is accessible */
+ /* Verify that the Scratch Register is accessible */
- WRITE( LCR, UART_LCR_DLAB );
- WRITE( DLL, 0x5a );
- if (READ(DLL) != 0x5a) return 0;
- WRITE( DLL, 0xa5 );
- if (READ(DLL) != 0xa5) return 0;
- WRITE( LCR, 0x00 );
+ IO_WRITE( SCR, 0x5a );
+ if (IO_READ(SCR) != 0x5a) return 0;
+ IO_WRITE( SCR, 0xa5 );
+ if (IO_READ(SCR) != 0xa5) return 0;
return 1;
}
static void
-uart_set_baud_rate( unsigned long baud_rate )
+legacy_uart_set_baud_rate( __unused int unit, uint32_t baud_rate )
{
- const unsigned char lcr = READ( LCR );
+ const unsigned char lcr = IO_READ( LCR );
unsigned long div;
if (baud_rate == 0) baud_rate = 9600;
- div = UART_CLOCK / 16 / baud_rate;
- WRITE( LCR, lcr | UART_LCR_DLAB );
- WRITE( DLM, (unsigned char)(div >> 8) );
- WRITE( DLL, (unsigned char) div );
- WRITE( LCR, lcr & ~UART_LCR_DLAB);
+ div = LEGACY_UART_CLOCK / 16 / baud_rate;
+ IO_WRITE( LCR, lcr | UART_LCR_DLAB );
+ IO_WRITE( DLM, (unsigned char)(div >> 8) );
+ IO_WRITE( DLL, (unsigned char) div );
+ IO_WRITE( LCR, lcr & ~UART_LCR_DLAB);
+}
+
+static int
+legacy_uart_tr0( void )
+{
+ return (IO_READ(LSR) & UART_LSR_THRE);
+}
+
+static void
+legacy_uart_td0( int c )
+{
+ IO_WRITE( THR, c );
}
static void
-uart_putc( char c )
+legacy_uart_init( void )
{
- if (!uart_initted) return;
+ /* Disable hardware interrupts */
+
+ IO_WRITE( MCR, 0 );
+ IO_WRITE( IER, 0 );
+
+ /* Disable FIFO's for 16550 devices */
+
+ IO_WRITE( FCR, 0 );
+
+ /* Set for 8-bit, no parity, DLAB bit cleared */
+
+ IO_WRITE( LCR, UART_LCR_8BITS );
+
+ /* Set baud rate */
- /* Wait for THR empty */
- while ( !(READ(LSR) & UART_LSR_THRE) ) DELAY(1);
+ gPESF->uart_set_baud_rate ( 0, uart_baud_rate );
- WRITE( THR, c );
+ /* Assert DTR# and RTS# lines (OUT2?) */
+
+ IO_WRITE( MCR, UART_MCR_DTR | UART_MCR_RTS );
+
+ /* Clear any garbage in the input buffer */
+
+ IO_READ( RBR );
+
+ uart_initted = 1;
}
static int
-uart_getc( void )
+legacy_uart_rr0( void )
{
- /*
- * This function returns:
- * -1 : no data
- * -2 : receiver error
- * >0 : character received
- */
-
unsigned char lsr;
- if (!uart_initted) return -1;
-
- lsr = READ( LSR );
+ lsr = IO_READ( LSR );
if ( lsr & (UART_LSR_FE | UART_LSR_PE | UART_LSR_OE) )
{
- READ( RBR ); /* discard */
- return -2;
+ IO_READ( RBR ); /* discard */
+ return 0;
}
- if ( lsr & UART_LSR_DR )
+ return (lsr & UART_LSR_DR);
+}
+
+static int
+legacy_uart_rd0( void )
+{
+ return IO_READ( RBR );
+}
+
+static struct pe_serial_functions legacy_uart_serial_functions = {
+ .uart_init = legacy_uart_init,
+ .uart_set_baud_rate = legacy_uart_set_baud_rate,
+ .tr0 = legacy_uart_tr0,
+ .td0 = legacy_uart_td0,
+ .rr0 = legacy_uart_rr0,
+ .rd0 = legacy_uart_rd0
+};
+
+// =============================================================================
+// MMIO UART (using PCH LPSS UART2)
+// =============================================================================
+
+#define MMIO_UART2_BASE_LEGACY 0xFE034000
+#define MMIO_UART2_BASE 0xFE036000
+
+#define MMIO_WRITE(r, v) ml_phys_write_word(mmio_uart_base + MMIO_UART_##r, v)
+#define MMIO_READ(r) ml_phys_read_word(mmio_uart_base + MMIO_UART_##r)
+
+enum {
+ MMIO_UART_RBR = 0x0, /* receive buffer Register (R) */
+ MMIO_UART_THR = 0x0, /* transmit holding register (W) */
+ MMIO_UART_DLL = 0x0, /* DLAB = 1, divisor latch (LSB) */
+ MMIO_UART_IER = 0x4, /* interrupt enable register */
+ MMIO_UART_DLM = 0x4, /* DLAB = 1, divisor latch (MSB) */
+ MMIO_UART_FCR = 0x8, /* fifo control register (W) */
+ MMIO_UART_LCR = 0xc, /* line control register */
+ MMIO_UART_MCR = 0x10, /* modem control register */
+ MMIO_UART_LSR = 0x14, /* line status register */
+ MMIO_UART_SCR = 0x1c /* scratch register */
+};
+
+static vm_offset_t mmio_uart_base = 0;
+
+static int
+mmio_uart_present( void )
+{
+ MMIO_WRITE( SCR, 0x5a );
+ if (MMIO_READ(SCR) != 0x5a) return 0;
+ MMIO_WRITE( SCR, 0xa5 );
+ if (MMIO_READ(SCR) != 0xa5) return 0;
+
+ return 1;
+}
+
+static int
+mmio_uart_probe( void )
+{
+ unsigned new_mmio_uart_base = 0;
+
+ // if specified, mmio_uart overrides all probing
+ if (PE_parse_boot_argn("mmio_uart", &new_mmio_uart_base, sizeof (new_mmio_uart_base)))
{
- return READ( RBR );
+ // mmio_uart=0 will disable mmio_uart support
+ if (new_mmio_uart_base == 0) {
+ return 0;
+ }
+
+ mmio_uart_base = new_mmio_uart_base;
+ return 1;
}
- return -1;
+ // probe the two possible MMIO_UART2 addresses
+ mmio_uart_base = MMIO_UART2_BASE;
+ if (mmio_uart_present()) {
+ return 1;
+ }
+
+ mmio_uart_base = MMIO_UART2_BASE_LEGACY;
+ if (mmio_uart_present()) {
+ return 1;
+ }
+
+ // no mmio uart found
+ return 0;
+}
+
+static void
+mmio_uart_set_baud_rate( __unused int unit, __unused uint32_t baud_rate )
+{
+ const unsigned char lcr = MMIO_READ( LCR );
+ unsigned long div;
+
+ if (baud_rate == 0) baud_rate = 9600;
+ div = LEGACY_UART_CLOCK / 16 / baud_rate;
+
+ MMIO_WRITE( LCR, lcr | UART_LCR_DLAB );
+ MMIO_WRITE( DLM, (unsigned char)(div >> 8) );
+ MMIO_WRITE( DLL, (unsigned char) div );
+ MMIO_WRITE( LCR, lcr & ~UART_LCR_DLAB);
+}
+
+static int
+mmio_uart_tr0( void )
+{
+ return (MMIO_READ(LSR) & UART_LSR_THRE);
}
-int serial_init( void )
+static void
+mmio_uart_td0( int c )
{
- unsigned serial_baud_rate = 0;
-
- if ( /*uart_initted ||*/ uart_probe() == 0 ) return 0;
+ MMIO_WRITE( THR, c );
+}
+static void
+mmio_uart_init( void )
+{
/* Disable hardware interrupts */
- WRITE( MCR, 0 );
- WRITE( IER, 0 );
+ MMIO_WRITE( MCR, 0 );
+ MMIO_WRITE( IER, 0 );
/* Disable FIFO's for 16550 devices */
- WRITE( FCR, 0 );
+ MMIO_WRITE( FCR, 0 );
/* Set for 8-bit, no parity, DLAB bit cleared */
- WRITE( LCR, UART_LCR_8BITS );
+ MMIO_WRITE( LCR, UART_LCR_8BITS );
- /* Set baud rate - use the supplied boot-arg if available */
+ /* Leave baud rate as set by firmware unless serialbaud boot-arg overrides */
- if (PE_parse_boot_arg("serialbaud", &serial_baud_rate))
+ if (uart_baud_rate != DEFAULT_UART_BAUD_RATE)
{
- /* Valid divisor? */
- if (!((UART_CLOCK / 16) % serial_baud_rate)) {
- uart_baud_rate = serial_baud_rate;
- }
+ gPESF->uart_set_baud_rate ( 0, uart_baud_rate );
}
- uart_set_baud_rate( uart_baud_rate );
/* Assert DTR# and RTS# lines (OUT2?) */
- WRITE( MCR, UART_MCR_DTR | UART_MCR_RTS );
+ MMIO_WRITE( MCR, UART_MCR_DTR | UART_MCR_RTS );
/* Clear any garbage in the input buffer */
- READ( RBR );
+ MMIO_READ( RBR );
uart_initted = 1;
+}
- return 1;
+static int
+mmio_uart_rr0( void )
+{
+ unsigned char lsr;
+
+ lsr = MMIO_READ( LSR );
+
+ if ( lsr & (UART_LSR_FE | UART_LSR_PE | UART_LSR_OE) )
+ {
+ MMIO_READ( RBR ); /* discard */
+ return 0;
+ }
+
+ return (lsr & UART_LSR_DR);
+}
+
+static int
+mmio_uart_rd0( void )
+{
+ return MMIO_READ( RBR );
+}
+
+static struct pe_serial_functions mmio_uart_serial_functions = {
+ .uart_init = mmio_uart_init,
+ .uart_set_baud_rate = mmio_uart_set_baud_rate,
+ .tr0 = mmio_uart_tr0,
+ .td0 = mmio_uart_td0,
+ .rr0 = mmio_uart_rr0,
+ .rd0 = mmio_uart_rd0
+};
+
+// =============================================================================
+// Generic serial support below
+// =============================================================================
+
+int
+serial_init( void )
+{
+ unsigned new_uart_baud_rate = 0;
+
+ if (PE_parse_boot_argn("serialbaud", &new_uart_baud_rate, sizeof (new_uart_baud_rate)))
+ {
+ /* Valid divisor? */
+ if (!((LEGACY_UART_CLOCK / 16) % new_uart_baud_rate)) {
+ uart_baud_rate = new_uart_baud_rate;
+ }
+ }
+
+ if ( mmio_uart_probe() )
+ {
+ gPESF = &mmio_uart_serial_functions;
+ gPESF->uart_init();
+ return 1;
+ }
+ else if ( legacy_uart_probe() )
+ {
+ gPESF = &legacy_uart_serial_functions;
+ gPESF->uart_init();
+ return 1;
+ }
+ else
+ {
+ return 0;
+ }
+
+}
+
+static void
+uart_putc(char c)
+{
+ if (uart_initted) {
+ while (!gPESF->tr0()); /* Wait until THR is empty. */
+ gPESF->td0(c);
+ }
+}
+
+static int
+uart_getc(void)
+{
+ if (uart_initted) {
+ if (!gPESF->rr0())
+ return -1;
+ return gPESF->rd0();
+ }
+ return -1;
}
-void serial_putc( char c )
+void
+serial_putc( char c )
{
uart_putc(c);
- if (c == '\n') uart_putc('\r');
}
-int serial_getc( void )
+int
+serial_getc( void )
{
return uart_getc();
}
projects / apple / xnu.git / blobdiff