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8250: Serial driver changes to support future Cavium OCTEON serial pa…
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…tches.

In order to use Cavium OCTEON specific serial i/o drivers, we first
patch the 8250 driver to use replaceable I/O functions.  Compatible
I/O functions are added for existing iotypeS.

An added benefit of this change is that it makes it easy to factor
some of the existing special cases out to board/SOC specific support
code.

The alternative is to load up 8250.c with a bunch of OCTEON specific
iotype code and bug work-arounds.

Signed-off-by: David Daney <[email protected]>
Signed-off-by: Tomaso Paoletti <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Alan Cox <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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@torvalds
David Daney authored and torvalds committed Jan 2, 2009
1 parent b430428 commit 7d6a07d
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Showing 3 changed files with 140 additions and 58 deletions.
194 changes: 136 additions & 58 deletions drivers/serial/8250.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -303,16 +303,16 @@ static const u8 au_io_out_map[] = {
};

/* sane hardware needs no mapping */
static inline int map_8250_in_reg(struct uart_8250_port *up, int offset)
static inline int map_8250_in_reg(struct uart_port *p, int offset)
{
if (up->port.iotype != UPIO_AU)
if (p->iotype != UPIO_AU)
return offset;
return au_io_in_map[offset];
}

static inline int map_8250_out_reg(struct uart_8250_port *up, int offset)
static inline int map_8250_out_reg(struct uart_port *p, int offset)
{
if (up->port.iotype != UPIO_AU)
if (p->iotype != UPIO_AU)
return offset;
return au_io_out_map[offset];
}
Expand Down Expand Up @@ -341,16 +341,16 @@ static const u8
[UART_SCR] = 0x2c
};

static inline int map_8250_in_reg(struct uart_8250_port *up, int offset)
static inline int map_8250_in_reg(struct uart_port *p, int offset)
{
if (up->port.iotype != UPIO_RM9000)
if (p->iotype != UPIO_RM9000)
return offset;
return regmap_in[offset];
}

static inline int map_8250_out_reg(struct uart_8250_port *up, int offset)
static inline int map_8250_out_reg(struct uart_port *p, int offset)
{
if (up->port.iotype != UPIO_RM9000)
if (p->iotype != UPIO_RM9000)
return offset;
return regmap_out[offset];
}
Expand All @@ -363,108 +363,170 @@ static inline int map_8250_out_reg(struct uart_8250_port *up, int offset)

#endif

static unsigned int serial_in(struct uart_8250_port *up, int offset)
static unsigned int hub6_serial_in(struct uart_port *p, int offset)
{
unsigned int tmp;
offset = map_8250_in_reg(up, offset) << up->port.regshift;
offset = map_8250_in_reg(p, offset) << p->regshift;
outb(p->hub6 - 1 + offset, p->iobase);
return inb(p->iobase + 1);
}

switch (up->port.iotype) {
case UPIO_HUB6:
outb(up->port.hub6 - 1 + offset, up->port.iobase);
return inb(up->port.iobase + 1);
static void hub6_serial_out(struct uart_port *p, int offset, int value)
{
offset = map_8250_out_reg(p, offset) << p->regshift;
outb(p->hub6 - 1 + offset, p->iobase);
outb(value, p->iobase + 1);
}

case UPIO_MEM:
case UPIO_DWAPB:
return readb(up->port.membase + offset);
static unsigned int mem_serial_in(struct uart_port *p, int offset)
{
offset = map_8250_in_reg(p, offset) << p->regshift;
return readb(p->membase + offset);
}

case UPIO_RM9000:
case UPIO_MEM32:
return readl(up->port.membase + offset);
static void mem_serial_out(struct uart_port *p, int offset, int value)
{
offset = map_8250_out_reg(p, offset) << p->regshift;
writeb(value, p->membase + offset);
}

static void mem32_serial_out(struct uart_port *p, int offset, int value)
{
offset = map_8250_out_reg(p, offset) << p->regshift;
writel(value, p->membase + offset);
}

static unsigned int mem32_serial_in(struct uart_port *p, int offset)
{
offset = map_8250_in_reg(p, offset) << p->regshift;
return readl(p->membase + offset);
}

#ifdef CONFIG_SERIAL_8250_AU1X00
case UPIO_AU:
return __raw_readl(up->port.membase + offset);
static unsigned int au_serial_in(struct uart_port *p, int offset)
{
offset = map_8250_in_reg(p, offset) << p->regshift;
return __raw_readl(p->membase + offset);
}

static void au_serial_out(struct uart_port *p, int offset, int value)
{
offset = map_8250_out_reg(p, offset) << p->regshift;
__raw_writel(value, p->membase + offset);
}
#endif

case UPIO_TSI:
if (offset == UART_IIR) {
tmp = readl(up->port.membase + (UART_IIR & ~3));
return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
} else
return readb(up->port.membase + offset);
static unsigned int tsi_serial_in(struct uart_port *p, int offset)
{
unsigned int tmp;
offset = map_8250_in_reg(p, offset) << p->regshift;
if (offset == UART_IIR) {
tmp = readl(p->membase + (UART_IIR & ~3));
return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
} else
return readb(p->membase + offset);
}

default:
return inb(up->port.iobase + offset);
}
static void tsi_serial_out(struct uart_port *p, int offset, int value)
{
offset = map_8250_out_reg(p, offset) << p->regshift;
if (!((offset == UART_IER) && (value & UART_IER_UUE)))
writeb(value, p->membase + offset);
}

static void
serial_out(struct uart_8250_port *up, int offset, int value)
static void dwapb_serial_out(struct uart_port *p, int offset, int value)
{
/* Save the offset before it's remapped */
int save_offset = offset;
offset = map_8250_out_reg(up, offset) << up->port.regshift;
offset = map_8250_out_reg(p, offset) << p->regshift;
/* Save the LCR value so it can be re-written when a
* Busy Detect interrupt occurs. */
if (save_offset == UART_LCR) {
struct uart_8250_port *up = (struct uart_8250_port *)p;
up->lcr = value;
}
writeb(value, p->membase + offset);
/* Read the IER to ensure any interrupt is cleared before
* returning from ISR. */
if (save_offset == UART_TX || save_offset == UART_IER)
value = p->serial_in(p, UART_IER);
}

switch (up->port.iotype) {
static unsigned int io_serial_in(struct uart_port *p, int offset)
{
offset = map_8250_in_reg(p, offset) << p->regshift;
return inb(p->iobase + offset);
}

static void io_serial_out(struct uart_port *p, int offset, int value)
{
offset = map_8250_out_reg(p, offset) << p->regshift;
outb(value, p->iobase + offset);
}

static void set_io_from_upio(struct uart_port *p)
{
switch (p->iotype) {
case UPIO_HUB6:
outb(up->port.hub6 - 1 + offset, up->port.iobase);
outb(value, up->port.iobase + 1);
p->serial_in = hub6_serial_in;
p->serial_out = hub6_serial_out;
break;

case UPIO_MEM:
writeb(value, up->port.membase + offset);
p->serial_in = mem_serial_in;
p->serial_out = mem_serial_out;
break;

case UPIO_RM9000:
case UPIO_MEM32:
writel(value, up->port.membase + offset);
p->serial_in = mem32_serial_in;
p->serial_out = mem32_serial_out;
break;

#ifdef CONFIG_SERIAL_8250_AU1X00
case UPIO_AU:
__raw_writel(value, up->port.membase + offset);
p->serial_in = au_serial_in;
p->serial_out = au_serial_out;
break;
#endif
case UPIO_TSI:
if (!((offset == UART_IER) && (value & UART_IER_UUE)))
writeb(value, up->port.membase + offset);
p->serial_in = tsi_serial_in;
p->serial_out = tsi_serial_out;
break;

case UPIO_DWAPB:
/* Save the LCR value so it can be re-written when a
* Busy Detect interrupt occurs. */
if (save_offset == UART_LCR)
up->lcr = value;
writeb(value, up->port.membase + offset);
/* Read the IER to ensure any interrupt is cleared before
* returning from ISR. */
if (save_offset == UART_TX || save_offset == UART_IER)
value = serial_in(up, UART_IER);
p->serial_in = mem_serial_in;
p->serial_out = dwapb_serial_out;
break;

default:
outb(value, up->port.iobase + offset);
p->serial_in = io_serial_in;
p->serial_out = io_serial_out;
break;
}
}

static void
serial_out_sync(struct uart_8250_port *up, int offset, int value)
{
switch (up->port.iotype) {
struct uart_port *p = &up->port;
switch (p->iotype) {
case UPIO_MEM:
case UPIO_MEM32:
#ifdef CONFIG_SERIAL_8250_AU1X00
case UPIO_AU:
#endif
case UPIO_DWAPB:
serial_out(up, offset, value);
serial_in(up, UART_LCR); /* safe, no side-effects */
p->serial_out(p, offset, value);
p->serial_in(p, UART_LCR); /* safe, no side-effects */
break;
default:
serial_out(up, offset, value);
p->serial_out(p, offset, value);
}
}

#define serial_in(up, offset) \
(up->port.serial_in(&(up)->port, (offset)))
#define serial_out(up, offset, value) \
(up->port.serial_out(&(up)->port, (offset), (value)))
/*
* We used to support using pause I/O for certain machines. We
* haven't supported this for a while, but just in case it's badly
Expand Down Expand Up @@ -2576,6 +2638,7 @@ static void __init serial8250_isa_init_ports(void)
up->port.membase = old_serial_port[i].iomem_base;
up->port.iotype = old_serial_port[i].io_type;
up->port.regshift = old_serial_port[i].iomem_reg_shift;
set_io_from_upio(&up->port);
if (share_irqs)
up->port.flags |= UPF_SHARE_IRQ;
}
Expand Down Expand Up @@ -2769,6 +2832,13 @@ int __init early_serial_setup(struct uart_port *port)
p->flags = port->flags;
p->mapbase = port->mapbase;
p->private_data = port->private_data;

set_io_from_upio(p);
if (port->serial_in)
p->serial_in = port->serial_in;
if (port->serial_out)
p->serial_out = port->serial_out;

return 0;
}

Expand Down Expand Up @@ -2833,6 +2903,8 @@ static int __devinit serial8250_probe(struct platform_device *dev)
port.mapbase = p->mapbase;
port.hub6 = p->hub6;
port.private_data = p->private_data;
port.serial_in = p->serial_in;
port.serial_out = p->serial_out;
port.dev = &dev->dev;
if (share_irqs)
port.flags |= UPF_SHARE_IRQ;
Expand Down Expand Up @@ -2986,6 +3058,12 @@ int serial8250_register_port(struct uart_port *port)
uart->port.private_data = port->private_data;
if (port->dev)
uart->port.dev = port->dev;
set_io_from_upio(&uart->port);
/* Possibly override default I/O functions. */
if (port->serial_in)
uart->port.serial_in = port->serial_in;
if (port->serial_out)
uart->port.serial_out = port->serial_out;

ret = uart_add_one_port(&serial8250_reg, &uart->port);
if (ret == 0)
Expand Down
2 changes: 2 additions & 0 deletions include/linux/serial_8250.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,8 @@ struct plat_serial8250_port {
unsigned char iotype; /* UPIO_* */
unsigned char hub6;
upf_t flags; /* UPF_* flags */
unsigned int (*serial_in)(struct uart_port *, int);
void (*serial_out)(struct uart_port *, int, int);
};

/*
Expand Down
2 changes: 2 additions & 0 deletions include/linux/serial_core.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -248,6 +248,8 @@ struct uart_port {
spinlock_t lock; /* port lock */
unsigned long iobase; /* in/out[bwl] */
unsigned char __iomem *membase; /* read/write[bwl] */
unsigned int (*serial_in)(struct uart_port *, int);
void (*serial_out)(struct uart_port *, int, int);
unsigned int irq; /* irq number */
unsigned int uartclk; /* base uart clock */
unsigned int fifosize; /* tx fifo size */
Expand Down

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