This is a follow up to the 'Allow for replaceable I/O functions in
8250 driver' patch I sent yesterday. I hope it addresses the issues
raised by Alan Cox and Arnd Bergmann.
The four parts of the patch are as follows:
1/4) Add replaceable I/O functions to the 8250 driver. This allows
platform specific register access code to be moved out of the
driver into the platform support files.
2/4) Add a new port flag UPF_FIXED_TYPE that allows callers of
serial8250_register_port() to specify the port type and disables
probing.
3/4) Add a 'bugs' field to the serial8250_config. Used in conjunction
with 2/4, this allows the bugs flags to be set without probing.
4/4) Add an entry to uart_config for PORT_OCTEON describing the
OCTEON's internal UARTs. Two new bug flags are defined to
account for PORT_OCTEON's peculiarities.
Comments welcome,
David Daney
In order to use Cavium OCTEON specific serial i/o drivers, we first patch
the 8250 driver to use replaceable i/o functions.
Signed-off-by: David Daney <[email protected]>
Signed-off-by: Tomaso Paoletti <[email protected]>
---
drivers/serial/8250.c | 185 +++++++++++++++++++++++++++++--------------
include/linux/serial_8250.h | 2 +
include/linux/serial_core.h | 2 +
3 files changed, 131 insertions(+), 58 deletions(-)
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 9ccc563..02771d6 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -288,16 +288,16 @@ 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];
}
@@ -326,16 +326,16 @@ 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];
}
@@ -348,108 +348,170 @@ 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_fn(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_fn(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_fn(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_fn(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_fn(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_fn(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_fn(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_fn(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_fn(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_fn(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_fn(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_fn(p, UART_IER);
+}
- switch (up->port.iotype) {
+static unsigned int io_serial_in_fn(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_fn(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_fns_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_fn = hub6_serial_in_fn;
+ p->serial_out_fn = hub6_serial_out_fn;
break;
case UPIO_MEM:
- writeb(value, up->port.membase + offset);
+ p->serial_in_fn = mem_serial_in_fn;
+ p->serial_out_fn = mem_serial_out_fn;
break;
case UPIO_RM9000:
case UPIO_MEM32:
- writel(value, up->port.membase + offset);
+ p->serial_in_fn = mem32_serial_in_fn;
+ p->serial_out_fn = mem32_serial_out_fn;
break;
#ifdef CONFIG_SERIAL_8250_AU1X00
case UPIO_AU:
- __raw_writel(value, up->port.membase + offset);
+ p->serial_in_fn = au_serial_in_fn;
+ p->serial_out_fn = au_serial_out_fn;
break;
#endif
case UPIO_TSI:
- if (!((offset == UART_IER) && (value & UART_IER_UUE)))
- writeb(value, up->port.membase + offset);
+ p->serial_in_fn = tsi_serial_in_fn;
+ p->serial_out_fn = tsi_serial_out_fn;
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_fn = mem_serial_in_fn;
+ p->serial_out_fn = dwapb_serial_out_fn;
break;
default:
- outb(value, up->port.iobase + offset);
+ p->serial_in_fn = io_serial_in_fn;
+ p->serial_out_fn = io_serial_out_fn;
+ 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_fn(p, offset, value);
+ p->serial_in_fn(p, UART_LCR); /* safe, no side-effects */
break;
default:
- serial_out(up, offset, value);
+ p->serial_out_fn(p, offset, value);
}
}
+#define serial_in(up, offset) \
+ (up->port.serial_in_fn(&(up)->port, (offset)))
+#define serial_out(up, offset, value) \
+ (up->port.serial_out_fn(&(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
@@ -2511,6 +2573,7 @@ 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_fns_from_upio(&up->port);
if (share_irqs)
up->port.flags |= UPF_SHARE_IRQ;
}
@@ -2912,6 +2975,12 @@ 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_fns_from_upio(&uart->port);
+ /* Possibly override default I/O functions. */
+ if (port->serial_in_fn)
+ uart->port.serial_in_fn = port->serial_in_fn;
+ if (port->serial_out_fn)
+ uart->port.serial_out_fn = port->serial_out_fn;
ret = uart_add_one_port(&serial8250_reg, &uart->port);
if (ret == 0)
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 3d37c94..eb08b04 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -28,6 +28,8 @@ struct plat_serial8250_port {
unsigned char iotype; /* UPIO_* */
unsigned char hub6;
upf_t flags; /* UPF_* flags */
+ unsigned int (*serial_in_fn)(struct uart_port *, int);
+ void (*serial_out_fn)(struct uart_port *, int, int);
};
/*
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 3b2f6c0..3a4afcf 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -243,6 +243,8 @@ struct uart_port {
spinlock_t lock; /* port lock */
unsigned int iobase; /* in/out[bwl] */
unsigned char __iomem *membase; /* read/write[bwl] */
+ unsigned int (*serial_in_fn)(struct uart_port *, int);
+ void (*serial_out_fn)(struct uart_port *, int, int);
unsigned int irq; /* irq number */
unsigned int uartclk; /* base uart clock */
unsigned int fifosize; /* tx fifo size */
Allow port type to be specified when calling serial8250_register_port.
Add flag value UPF_FIXED_TYPE which specifies that the UART type is
known and should not be probed. For this case the UARTs properties
are just copied out of the uart_config entry.
Signed-off-by: David Daney <[email protected]>
---
drivers/serial/8250.c | 8 ++++++++
drivers/serial/serial_core.c | 7 +++++--
include/linux/serial_core.h | 2 ++
3 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 02771d6..c575b61 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2975,6 +2975,14 @@ int serial8250_register_port(struct uart_port *port)
uart->port.private_data = port->private_data;
if (port->dev)
uart->port.dev = port->dev;
+
+ if (port->flags & UPF_FIXED_TYPE) {
+ uart->port.type = port->type;
+ uart->port.fifosize = uart_config[port->type].fifo_size;
+ uart->capabilities = uart_config[port->type].flags;
+ uart->tx_loadsz = uart_config[port->type].tx_loadsz;
+ }
+
set_io_fns_from_upio(&uart->port);
/* Possibly override default I/O functions. */
if (port->serial_in_fn)
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index f977c98..65b8a74 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -2196,11 +2196,14 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
* Now do the auto configuration stuff. Note that config_port
* is expected to claim the resources and map the port for us.
*/
- flags = UART_CONFIG_TYPE;
+ flags = 0;
if (port->flags & UPF_AUTO_IRQ)
flags |= UART_CONFIG_IRQ;
if (port->flags & UPF_BOOT_AUTOCONF) {
- port->type = PORT_UNKNOWN;
+ if (!(port->flags & UPF_FIXED_TYPE)) {
+ port->type = PORT_UNKNOWN;
+ flags |= UART_CONFIG_TYPE;
+ }
port->ops->config_port(port, flags);
}
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 3a4afcf..c68dc94 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -290,6 +290,8 @@ struct uart_port {
#define UPF_MAGIC_MULTIPLIER ((__force upf_t) (1 << 16))
#define UPF_CONS_FLOW ((__force upf_t) (1 << 23))
#define UPF_SHARE_IRQ ((__force upf_t) (1 << 24))
+/* The exact UART type is known and should not be probed. */
+#define UPF_FIXED_TYPE ((__force upf_t) (1 << 27))
#define UPF_BOOT_AUTOCONF ((__force upf_t) (1 << 28))
#define UPF_FIXED_PORT ((__force upf_t) (1 << 29))
#define UPF_DEAD ((__force upf_t) (1 << 30))
Allow port type to specify bugs that are not probed for.
Add a bugs field to the serial8250_config and propagate it to the
port's bugs field when the port is registered and configured.
Signed-off-by: David Daney <[email protected]>
---
drivers/serial/8250.c | 2 ++
drivers/serial/8250.h | 1 +
2 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index c575b61..19a8373 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1197,6 +1197,7 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
up->port.fifosize = uart_config[up->port.type].fifo_size;
up->capabilities = uart_config[up->port.type].flags;
up->tx_loadsz = uart_config[up->port.type].tx_loadsz;
+ up->bugs |= uart_config[up->port.type].bugs;
if (up->port.type == PORT_UNKNOWN)
goto out;
@@ -2981,6 +2982,7 @@ int serial8250_register_port(struct uart_port *port)
uart->port.fifosize = uart_config[port->type].fifo_size;
uart->capabilities = uart_config[port->type].flags;
uart->tx_loadsz = uart_config[port->type].tx_loadsz;
+ uart->bugs = uart_config[port->type].bugs;
}
set_io_fns_from_upio(&uart->port);
diff --git a/drivers/serial/8250.h b/drivers/serial/8250.h
index 5202603..c9b3002 100644
--- a/drivers/serial/8250.h
+++ b/drivers/serial/8250.h
@@ -34,6 +34,7 @@ struct serial8250_config {
const char *name;
unsigned short fifo_size;
unsigned short tx_loadsz;
+ unsigned short bugs;
unsigned char fcr;
unsigned int flags;
};
Cavium UART implementation won't work with the standard 8250 driver
as-is. Define a new uart_config (PORT_OCTEON) and use it to enable
special handling required by the OCTEON's serial port.
Signed-off-by: Tomaso Paoletti <[email protected]>
Signed-off-by: Paul Gortmaker <[email protected]>
Signed-off-by: David Daney <[email protected]>
---
drivers/serial/8250.c | 16 +++++++++++++++-
drivers/serial/8250.h | 2 ++
include/linux/serial_core.h | 3 ++-
include/linux/serial_reg.h | 6 ++++++
4 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 19a8373..7afd07f 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -264,6 +264,14 @@ static const struct serial8250_config uart_config[] = {
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
.flags = UART_CAP_FIFO,
},
+ [PORT_OCTEON] = {
+ .name = "OCTEON",
+ .fifo_size = 64,
+ .tx_loadsz = 64,
+ .bugs = UART_BUG_TIMEOUT | UART_BUG_OCTEON_IIR,
+ .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+ .flags = UART_CAP_FIFO,
+ },
};
#if defined (CONFIG_SERIAL_8250_AU1X00)
@@ -1540,6 +1548,12 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
up = list_entry(l, struct uart_8250_port, list);
iir = serial_in(up, UART_IIR);
+ if ((up->bugs & UART_BUG_OCTEON_IIR) && (iir & 0xf) == 7) {
+ /* Busy interrupt */
+ serial_in(up, UART_OCTEON_USR);
+ iir = serial_in(up, UART_IIR);
+ }
+
if (!(iir & UART_IIR_NO_INT)) {
serial8250_handle_port(up);
@@ -1658,7 +1672,7 @@ static void serial8250_timeout(unsigned long data)
unsigned int iir;
iir = serial_in(up, UART_IIR);
- if (!(iir & UART_IIR_NO_INT))
+ if (!(iir & UART_IIR_NO_INT) || (up->bugs & UART_BUG_TIMEOUT))
serial8250_handle_port(up);
mod_timer(&up->timer, jiffies + poll_timeout(up->port.timeout));
}
diff --git a/drivers/serial/8250.h b/drivers/serial/8250.h
index c9b3002..56b3cb7 100644
--- a/drivers/serial/8250.h
+++ b/drivers/serial/8250.h
@@ -49,6 +49,8 @@ struct serial8250_config {
#define UART_BUG_TXEN (1 << 1) /* UART has buggy TX IIR status */
#define UART_BUG_NOMSR (1 << 2) /* UART has buggy MSR status bits (Au1x00) */
#define UART_BUG_THRE (1 << 3) /* UART has buggy THRE reassertion */
+#define UART_BUG_TIMEOUT (1 << 4) /* UART should always handle timeout */
+#define UART_BUG_OCTEON_IIR (1 << 5) /* UART OCTEON IIR workaround */
#define PROBE_RSA (1 << 0)
#define PROBE_ANY (~0)
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index c68dc94..c920c43 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -40,7 +40,8 @@
#define PORT_NS16550A 14
#define PORT_XSCALE 15
#define PORT_RM9000 16 /* PMC-Sierra RM9xxx internal UART */
-#define PORT_MAX_8250 16 /* max port ID */
+#define PORT_OCTEON 17 /* Cavium OCTEON internal UART */
+#define PORT_MAX_8250 17 /* max port ID */
/*
* ARM specific type numbers. These are not currently guaranteed
diff --git a/include/linux/serial_reg.h b/include/linux/serial_reg.h
index 96c0d93..a96bd50 100644
--- a/include/linux/serial_reg.h
+++ b/include/linux/serial_reg.h
@@ -324,5 +324,11 @@
#define UART_OMAP_SYSC 0x15 /* System configuration register */
#define UART_OMAP_SYSS 0x16 /* System status register */
+/*
+ * Extra serial register definitions for the internal UARTs in Cavium
+ * Networks OCTEON processors.
+ */
+#define UART_OCTEON_USR 0x27 /* UART Status Register */
+
#endif /* _LINUX_SERIAL_REG_H */
David Daney wrote:
> /* 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];
> }
With your changes, these functions cannot be called with p->iotype !=
UPIO_AU anymore, correct? So there is no need for this test...
-hpa
H. Peter Anvin wrote:
> David Daney wrote:
>> /* 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];
>> }
>
> With your changes, these functions cannot be called with p->iotype !=
> UPIO_AU anymore, correct? So there is no need for this test...
>
I think you are probably correct. However, with the patch it is
possible to move all this target specific code out of the driver. So if
the patch is accepted, a better follow up would be to get rid of the
UPIO_AU things altogether.
I gave an example of how that could be done with UPIO_TSI here:
http://marc.info/?l=linux-serial&m=122333633802691&w=2
David Daney