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authorMarc St-Jean <stjeanma@pmc-sierra.com>2007-05-06 14:48:45 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-07 12:12:50 -0700
commitbeab697ab4b2962e3d741b476abe443baad0933d (patch)
treef581ce38378f6cacbf0042b4eb9c084a6fc932d9 /arch/mips
parent6179b5562d5d17c7c09b54cb11dd925ca308d7a9 (diff)
serial driver PMC MSP71xx
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@pmc-sierra.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/mips')
-rw-r--r--arch/mips/pmc-sierra/msp71xx/msp_serial.c165
1 files changed, 165 insertions, 0 deletions
diff --git a/arch/mips/pmc-sierra/msp71xx/msp_serial.c b/arch/mips/pmc-sierra/msp71xx/msp_serial.c
new file mode 100644
index 00000000000..c41b53faa8f
--- /dev/null
+++ b/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");
+}