This adds the ability for the driver to access UARTs via MMIO instead
of PIO selectively at runtime, and exposes a new function to add an
MMIO port.
Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
---
docs/grub.texi | 3 +-
grub-core/term/ns8250.c | 78 ++++++++++++++++++++++++++++++++---------
grub-core/term/serial.c | 22 ++++++++++--
include/grub/serial.h | 10 +++++-
4 files changed, 92 insertions(+), 21 deletions(-)
diff --git a/docs/grub.texi b/docs/grub.texi
index eeb3118eb..4a3287119 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -3878,7 +3878,8 @@ Commands usable anywhere in the menu and in the
command-line.
Initialize a serial device. @var{unit} is a number in the range 0-3
specifying which serial port to use; default is 0, which corresponds to
the port often called COM1. @var{port} is the I/O port where the UART
-is to be found; if specified it takes precedence over @var{unit}.
+is to be found; if specified it takes precedence over @var{unit}. It can
+also be ``mmio'' followed by the MMIO address of the port in hexadecimal.
@var{speed} is the transmission speed; default is 9600. @var{word} and
@var{stop} are the number of data bits and stop bits. Data bits must
be in the range 5-8 and stop bits must be 1 or 2. Default is 8 data
diff --git a/grub-core/term/ns8250.c b/grub-core/term/ns8250.c
index 39809d042..183e14b3b 100644
--- a/grub-core/term/ns8250.c
+++ b/grub-core/term/ns8250.c
@@ -44,6 +44,24 @@ static int dead_ports = 0;
#define DEFAULT_BASE_CLOCK 115200
#endif
+static inline unsigned char
+ns8250_reg_read (struct grub_serial_port *port, grub_addr_t reg)
+{
+ asm volatile("" : : : "memory");
+ if (port->mmio)
+ return *((volatile unsigned char *)(port->mmio_base + reg));
+ return grub_inb (port->port + reg);
+}
+
+static inline void
+ns8250_reg_write (struct grub_serial_port *port, unsigned char value,
grub_addr_t reg)
+{
+ asm volatile("" : : : "memory");
+ if (port->mmio)
+ *((volatile char *)(port->mmio_base + reg)) = value;
+ else
+ grub_outb (value, port->port + reg);
+}
/* Convert speed to divisor. */
static unsigned short
@@ -94,43 +112,42 @@ do_real_config (struct grub_serial_port *port)
divisor = serial_get_divisor (port, &port->config);
/* Turn off the interrupt. */
- grub_outb (0, port->port + UART_IER);
+ ns8250_reg_write (port, 0, UART_IER);
/* Set DLAB. */
- grub_outb (UART_DLAB, port->port + UART_LCR);
+ ns8250_reg_write (port, UART_DLAB, UART_LCR);
- /* Set the baud rate. */
- grub_outb (divisor & 0xFF, port->port + UART_DLL);
- grub_outb (divisor >> 8, port->port + UART_DLH);
+ ns8250_reg_write (port, divisor & 0xFF, UART_DLL);
+ ns8250_reg_write (port, divisor >> 8, UART_DLH);
/* Set the line status. */
status |= (parities[port->config.parity]
| (port->config.word_len - 5)
| stop_bits[port->config.stop_bits]);
- grub_outb (status, port->port + UART_LCR);
+ ns8250_reg_write (port, status, UART_LCR);
if (port->config.rtscts)
{
/* Enable the FIFO. */
- grub_outb (UART_ENABLE_FIFO_TRIGGER1, port->port + UART_FCR);
+ ns8250_reg_write (port, UART_ENABLE_FIFO_TRIGGER1, UART_FCR);
/* Turn on DTR and RTS. */
- grub_outb (UART_ENABLE_DTRRTS, port->port + UART_MCR);
+ ns8250_reg_write (port, UART_ENABLE_DTRRTS, UART_MCR);
}
else
{
/* Enable the FIFO. */
- grub_outb (UART_ENABLE_FIFO_TRIGGER14, port->port + UART_FCR);
+ ns8250_reg_write (port, UART_ENABLE_FIFO_TRIGGER14, UART_FCR);
/* Turn on DTR, RTS, and OUT2. */
- grub_outb (UART_ENABLE_DTRRTS | UART_ENABLE_OUT2, port->port + UART_MCR);
+ ns8250_reg_write (port, UART_ENABLE_DTRRTS | UART_ENABLE_OUT2, UART_MCR);
}
/* Drain the input buffer. */
endtime = grub_get_time_ms () + 1000;
- while (grub_inb (port->port + UART_LSR) & UART_DATA_READY)
+ while (ns8250_reg_read (port, UART_LSR) & UART_DATA_READY)
{
- grub_inb (port->port + UART_RX);
+ ns8250_reg_read (port, UART_RX);
if (grub_get_time_ms () > endtime)
{
port->broken = 1;
@@ -146,8 +163,8 @@ static int
serial_hw_fetch (struct grub_serial_port *port)
{
do_real_config (port);
- if (grub_inb (port->port + UART_LSR) & UART_DATA_READY)
- return grub_inb (port->port + UART_RX);
+ if (ns8250_reg_read (port, UART_LSR) & UART_DATA_READY)
+ return ns8250_reg_read (port, UART_RX);
return -1;
}
@@ -167,7 +184,7 @@ serial_hw_put (struct grub_serial_port *port, const int c)
else
endtime = grub_get_time_ms () + 200;
/* Wait until the transmitter holding register is empty. */
- while ((grub_inb (port->port + UART_LSR) & UART_EMPTY_TRANSMITTER) == 0)
+ while ((ns8250_reg_read (port, UART_LSR) & UART_EMPTY_TRANSMITTER) == 0)
{
if (grub_get_time_ms () > endtime)
{
@@ -180,7 +197,7 @@ serial_hw_put (struct grub_serial_port *port, const int c)
if (port->broken)
port->broken--;
- grub_outb (c, port->port + UART_TX);
+ ns8250_reg_write (port, c, UART_TX);
}
/* Initialize a serial device. PORT is the port number for a serial device.
@@ -260,6 +277,7 @@ grub_ns8250_init (void)
com_ports[i].name = com_names[i];
com_ports[i].driver = &grub_ns8250_driver;
com_ports[i].port = serial_hw_io_addr[i];
+ com_ports[i].mmio = 0;
err = grub_serial_config_defaults (&com_ports[i]);
if (err)
grub_print_error ();
@@ -311,8 +329,36 @@ grub_serial_ns8250_add_port (grub_port_t port)
}
p->driver = &grub_ns8250_driver;
grub_serial_config_defaults (p);
+ p->mmio = 0;
p->port = port;
grub_serial_register (p);
return p->name;
}
+
+char *
+grub_serial_ns8250_add_mmio(grub_addr_t addr)
+{
+ struct grub_serial_port *p;
+ unsigned i;
+ for (i = 0; i < GRUB_SERIAL_PORT_NUM; i++)
+ if (com_ports[i].mmio && com_ports[i].mmio_base == addr)
+ return com_names[i];
+
+ p = grub_malloc (sizeof (*p));
+ if (!p)
+ return NULL;
+ p->name = grub_xasprintf ("mmio%llx", (unsigned long long) addr);
+ if (!p->name)
+ {
+ grub_free (p);
+ return NULL;
+ }
+ p->driver = &grub_ns8250_driver;
+ grub_serial_config_defaults (p);
+ p->mmio = 1;
+ p->mmio_base = addr;
+ grub_serial_register (p);
+
+ return p->name;
+}
diff --git a/grub-core/term/serial.c b/grub-core/term/serial.c
index f9271b092..7d4dbb2de 100644
--- a/grub-core/term/serial.c
+++ b/grub-core/term/serial.c
@@ -160,6 +160,18 @@ grub_serial_find (const char *name)
if (!name)
return NULL;
+ FOR_SERIAL_PORTS (port)
+ if (grub_strcmp (port->name, name) == 0)
+ break;
+ }
+ if (!port && grub_memcmp (name, "mmio", sizeof ("mmio") - 1) == 0
+ && grub_isxdigit (name [sizeof ("mmio") - 1]))
+ {
+ name = grub_serial_ns8250_add_mmio (grub_strtoul (&name[sizeof ("mmio")
- 1],
+ 0, 16), NULL);
+ if (!name)
+ return NULL;
+
FOR_SERIAL_PORTS (port)
if (grub_strcmp (port->name, name) == 0)
break;
@@ -195,14 +207,18 @@ grub_cmd_serial (grub_extcmd_context_t ctxt, int argc,
char **args)
if (state[OPTION_UNIT].set)
{
grub_snprintf (pname, sizeof (pname), "com%ld",
- grub_strtoul (state[0].arg, 0, 0));
+ grub_strtoul (state[OPTION_UNIT].arg, 0, 0));
name = pname;
}
if (state[OPTION_PORT].set)
{
- grub_snprintf (pname, sizeof (pname), "port%lx",
- grub_strtoul (state[1].arg, 0, 0));
+ if (grub_memcmp (state[OPTION_PORT].arg, "mmio", 4) == 0)
+ grub_snprintf(pname, sizeof (pname), "%s", state[OPTION_PORT].arg);
+ else
+ grub_snprintf (pname, sizeof (pname), "port%lx",
+ grub_strtoul (state[OPTION_PORT].arg, 0, 0));
+
name = pname;
}
diff --git a/include/grub/serial.h b/include/grub/serial.h
index 67379de45..a5756cd25 100644
--- a/include/grub/serial.h
+++ b/include/grub/serial.h
@@ -86,9 +86,16 @@ struct grub_serial_port
*/
union
{
+ struct
+ {
+ int mmio;
+ union {
#if defined(__mips__) || defined (__i386__) || defined (__x86_64__)
- grub_port_t port;
+ grub_port_t port;
#endif
+ grub_addr_t mmio_base;
+ };
+ };
struct
{
grub_usb_device_t usbdev;
@@ -178,6 +185,7 @@ grub_serial_config_defaults (struct grub_serial_port *port)
#if defined(__mips__) || defined (__i386__) || defined (__x86_64__)
void grub_ns8250_init (void);
char *grub_serial_ns8250_add_port (grub_port_t port);
+char *grub_serial_ns8250_add_mmio(grub_addr_t addr);
#endif
#ifdef GRUB_MACHINE_IEEE1275
void grub_ofserial_init (void);
--
2.25.1
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