The patch titled
serial driver PMC MSP71xx
has been added to the -mm tree. Its filename is
serial-driver-pmc-msp71xx.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: serial driver PMC MSP71xx
From: Marc St-Jean <stjeanma@xxxxxxxxxxxxxx>
Serial driver patch for the PMC-Sierra MSP71xx devices.
There are three different fixes:
1 Fix for DesignWare APB THRE errata: In brief, this is a non-standard
16550 in that the THRE interrupt will not re-assert itself simply by
disabling and re-enabling the THRI bit in the IER, it is only re-enabled
if a character is actually sent out.
It appears that the "8250-uart-backup-timer.patch" in the "mm" tree
also fixes it so we have dropped our initial workaround. This patch now
needs to be applied on top of that "mm" patch.
2 Fix for Busy Detect on LCR write: The DesignWare APB UART has a feature
which causes a new Busy Detect interrupt to be generated if it's busy
when the LCR is written. This fix saves the value of the LCR and
rewrites it after clearing the interrupt.
3 Workaround for interrupt/data concurrency issue: The SoC needs to
ensure that writes that can cause interrupts to be cleared reach the UART
before returning from the ISR. This fix reads a non-destructive register
on the UART so the read transaction completion ensures the previously
queued write transaction has also completed.
Signed-off-by: Marc St-Jean <Marc_St-Jean@xxxxxxxxxxxxxx>
Cc: Russell King <rmk@xxxxxxxxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/mips/pmc-sierra/msp71xx/msp_serial.c | 165 ++++++++++++++++++++
drivers/serial/8250.c | 31 +++
drivers/serial/serial_core.c | 2
include/linux/serial_core.h | 2
include/linux/serial_reg.h | 2
5 files changed, 202 insertions(+)
diff -puN /dev/null arch/mips/pmc-sierra/msp71xx/msp_serial.c
--- /dev/null
+++ a/arch/mips/pmc-sierra/msp71xx/msp_serial.c
@@ -0,0 +1,165 @@
+/*
+ * The setup file for serial related hardware on PMC-Sierra MSP processors.
+ *
+ * Copyright 2005 PMC-Sierra, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+
+#include <asm/bootinfo.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/serial.h>
+
+#include <msp_prom.h>
+#include <msp_int.h>
+#include <msp_regs.h>
+
+#ifdef CONFIG_KGDB
+/*
+ * kgdb uses serial port 1 so the console can remain on port 0.
+ * To use port 0 change the definition to read as follows:
+ * #define DEBUG_PORT_BASE KSEG1ADDR(MSP_UART0_BASE)
+ */
+#define DEBUG_PORT_BASE KSEG1ADDR(MSP_UART1_BASE)
+
+int putDebugChar(char c)
+{
+ volatile uint32_t *uart = (volatile uint32_t *)DEBUG_PORT_BASE;
+ uint32_t val = (uint32_t)c;
+
+ local_irq_disable();
+ while( !(uart[5] & 0x20) ); /* Wait for TXRDY */
+ uart[0] = val;
+ while( !(uart[5] & 0x20) ); /* Wait for TXRDY */
+ local_irq_enable();
+
+ return 1;
+}
+
+char getDebugChar(void)
+{
+ volatile uint32_t *uart = (volatile uint32_t *)DEBUG_PORT_BASE;
+ uint32_t val;
+
+ while( !(uart[5] & 0x01) ); /* Wait for RXRDY */
+ val = uart[0];
+
+ return (char)val;
+}
+
+void initDebugPort(unsigned int uartclk, unsigned int baudrate)
+{
+ unsigned int baud_divisor = (uartclk + 8 * baudrate)/(16 * baudrate);
+
+ /* Enable FIFOs */
+ writeb(UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
+ UART_FCR_CLEAR_XMIT | UART_FCR_TRIGGER_4,
+ (char *)DEBUG_PORT_BASE + (UART_FCR * 4));
+
+ /* Select brtc divisor */
+ writeb(UART_LCR_DLAB, (char *)DEBUG_PORT_BASE + (UART_LCR * 4));
+
+ /* Store divisor lsb */
+ writeb(baud_divisor, (char *)DEBUG_PORT_BASE + (UART_TX * 4));
+
+ /* Store divisor msb */
+ writeb(baud_divisor >> 8, (char *)DEBUG_PORT_BASE + (UART_IER * 4));
+
+ /* Set 8N1 mode */
+ writeb(UART_LCR_WLEN8, (char *)DEBUG_PORT_BASE + (UART_LCR * 4));
+
+ /* Disable flow control */
+ writeb(0, (char *)DEBUG_PORT_BASE + (UART_MCR * 4));
+
+ /* Disable receive interrupt(!) */
+ writeb(0, (char *)DEBUG_PORT_BASE + (UART_IER * 4));
+}
+#endif
+
+void __init msp_serial_setup(void)
+{
+ char *s;
+ char *endp;
+ struct uart_port up;
+ unsigned int uartclk;
+
+ memset(&up, 0, sizeof(up));
+
+ /* Check if clock was specified in environment */
+ s = prom_getenv("uartfreqhz");
+ if(!(s && *s && (uartclk = simple_strtoul(s, &endp, 10)) && *endp == 0))
+ uartclk = MSP_BASE_BAUD;
+ ppfinit("UART clock set to %d\n", uartclk);
+
+ /* Initialize first serial port */
+ up.mapbase = MSP_UART0_BASE;
+ up.membase = ioremap_nocache(up.mapbase,MSP_UART_REG_LEN);
+ up.irq = MSP_INT_UART0;
+ up.uartclk = uartclk;
+ up.regshift = 2;
+ up.iotype = UPIO_DWAPB; /* UPIO_MEM like */
+ up.flags = STD_COM_FLAGS;
+ up.type = PORT_16550A;
+ up.line = 0;
+ up.private_data = (void*)UART0_STATUS_REG;
+ if (early_serial_setup(&up))
+ printk(KERN_ERR "Early serial init of port 0 failed\n");
+
+ /* Initialize the second serial port, if one exists */
+ switch (mips_machtype) {
+ case MACH_MSP4200_EVAL:
+ case MACH_MSP4200_GW:
+ case MACH_MSP4200_FPGA:
+ case MACH_MSP7120_EVAL:
+ case MACH_MSP7120_GW:
+ case MACH_MSP7120_FPGA:
+ /* Enable UART1 on MSP4200 and MSP7120 */
+ *GPIO_CFG2_REG = 0x00002299;
+
+#ifdef CONFIG_KGDB
+ /* Initialize UART1 for kgdb since PMON doesn't */
+ if( DEBUG_PORT_BASE == KSEG1ADDR(MSP_UART1_BASE) ) {
+ if( mips_machtype == MACH_MSP4200_FPGA
+ || mips_machtype == MACH_MSP7120_FPGA )
+ initDebugPort(uartclk,19200);
+ else
+ initDebugPort(uartclk,57600);
+ }
+#endif
+ break;
+
+ default:
+ return; /* No second serial port, good-bye. */
+ }
+
+ up.mapbase = MSP_UART1_BASE;
+ up.membase = ioremap_nocache(up.mapbase,MSP_UART_REG_LEN);
+ up.irq = MSP_INT_UART1;
+ up.line = 1;
+ up.private_data = (void*)UART1_STATUS_REG;
+ if (early_serial_setup(&up))
+ printk(KERN_ERR "Early serial init of port 1 failed\n");
+}
diff -puN drivers/serial/8250.c~serial-driver-pmc-msp71xx drivers/serial/8250.c
--- a/drivers/serial/8250.c~serial-driver-pmc-msp71xx
+++ a/drivers/serial/8250.c
@@ -308,6 +308,7 @@ static unsigned int serial_in(struct uar
return inb(up->port.iobase + 1);
case UPIO_MEM:
+ case UPIO_DWAPB:
return readb(up->port.membase + offset);
case UPIO_MEM32:
@@ -333,6 +334,8 @@ static unsigned int serial_in(struct uar
static void
serial_out(struct uart_8250_port *up, 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;
switch (up->port.iotype) {
@@ -359,6 +362,18 @@ serial_out(struct uart_8250_port *up, in
writeb(value, up->port.membase + offset);
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);
+ break;
+
default:
outb(value, up->port.iobase + offset);
}
@@ -373,6 +388,7 @@ serial_out_sync(struct uart_8250_port *u
#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 */
break;
@@ -1387,6 +1403,19 @@ static irqreturn_t serial8250_interrupt(
handled = 1;
end = NULL;
+ } else if (up->port.iotype == UPIO_DWAPB &&
+ (iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
+ /* The DesignWare APB UART has an Busy Detect (0x07)
+ * interrupt meaning an LCR write attempt occured while the
+ * UART was busy. The interrupt must be cleared by reading
+ * the UART status register (USR) and the LCR re-written. */
+ unsigned int status;
+ status = *(volatile u32 *)up->port.private_data;
+ serial_out(up, UART_LCR, up->lcr);
+
+ handled = 1;
+
+ end = NULL;
} else if (end == NULL)
end = l;
@@ -2091,6 +2120,7 @@ static int serial8250_request_std_resour
case UPIO_TSI:
case UPIO_MEM32:
case UPIO_MEM:
+ case UPIO_DWAPB:
if (!up->port.mapbase)
break;
@@ -2128,6 +2158,7 @@ static void serial8250_release_std_resou
case UPIO_TSI:
case UPIO_MEM32:
case UPIO_MEM:
+ case UPIO_DWAPB:
if (!up->port.mapbase)
break;
diff -puN drivers/serial/serial_core.c~serial-driver-pmc-msp71xx drivers/serial/serial_core.c
--- a/drivers/serial/serial_core.c~serial-driver-pmc-msp71xx
+++ a/drivers/serial/serial_core.c
@@ -2064,6 +2064,7 @@ uart_report_port(struct uart_driver *drv
case UPIO_MEM32:
case UPIO_AU:
case UPIO_TSI:
+ case UPIO_DWAPB:
snprintf(address, sizeof(address),
"MMIO 0x%lx", port->mapbase);
break;
@@ -2409,6 +2410,7 @@ int uart_match_port(struct uart_port *po
case UPIO_MEM32:
case UPIO_AU:
case UPIO_TSI:
+ case UPIO_DWAPB:
return (port1->mapbase == port2->mapbase);
}
return 0;
diff -puN include/linux/serial_core.h~serial-driver-pmc-msp71xx include/linux/serial_core.h
--- a/include/linux/serial_core.h~serial-driver-pmc-msp71xx
+++ a/include/linux/serial_core.h
@@ -230,6 +230,7 @@ struct uart_port {
#define UPIO_MEM32 (3)
#define UPIO_AU (4) /* Au1x00 type IO */
#define UPIO_TSI (5) /* Tsi108/109 type IO */
+#define UPIO_DWAPB (6) /* DesignWare APB UART */
unsigned int read_status_mask; /* driver specific */
unsigned int ignore_status_mask; /* driver specific */
@@ -276,6 +277,7 @@ struct uart_port {
struct device *dev; /* parent device */
unsigned char hub6; /* this should be in the 8250 driver */
unsigned char unused[3];
+ void *private_data; /* generic platform data pointer */
};
/*
diff -puN include/linux/serial_reg.h~serial-driver-pmc-msp71xx include/linux/serial_reg.h
--- a/include/linux/serial_reg.h~serial-driver-pmc-msp71xx
+++ a/include/linux/serial_reg.h
@@ -38,6 +38,8 @@
#define UART_IIR_RDI 0x04 /* Receiver data interrupt */
#define UART_IIR_RLSI 0x06 /* Receiver line status interrupt */
+#define UART_IIR_BUSY 0x07 /* DesignWare APB Busy Detect */
+
#define UART_FCR 2 /* Out: FIFO Control Register */
#define UART_FCR_ENABLE_FIFO 0x01 /* Enable the FIFO */
#define UART_FCR_CLEAR_RCVR 0x02 /* Clear the RCVR FIFO */
_
Patches currently in -mm which might be from stjeanma@xxxxxxxxxxxxxx are
serial-driver-pmc-msp71xx.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
