forked from Minki/linux
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>
This commit is contained in:
Marc St-Jean
Linus Torvalds
parent
6179b5562d
commit
beab697ab4
165
arch/mips/pmc-sierra/msp71xx/msp_serial.c
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165
arch/mips/pmc-sierra/msp71xx/msp_serial.c
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@ -0,0 +1,165 @@
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/*
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* The setup file for serial related hardware on PMC-Sierra MSP processors.
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*
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* Copyright 2005 PMC-Sierra, Inc.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
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* NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/serial.h>
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#include <linux/serial_core.h>
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#include <linux/serial_reg.h>
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#include <asm/bootinfo.h>
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#include <asm/io.h>
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#include <asm/processor.h>
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#include <asm/serial.h>
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#include <msp_prom.h>
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#include <msp_int.h>
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#include <msp_regs.h>
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#ifdef CONFIG_KGDB
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/*
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* kgdb uses serial port 1 so the console can remain on port 0.
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* To use port 0 change the definition to read as follows:
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* #define DEBUG_PORT_BASE KSEG1ADDR(MSP_UART0_BASE)
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*/
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#define DEBUG_PORT_BASE KSEG1ADDR(MSP_UART1_BASE)
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int putDebugChar(char c)
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{
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volatile uint32_t *uart = (volatile uint32_t *)DEBUG_PORT_BASE;
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uint32_t val = (uint32_t)c;
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local_irq_disable();
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while( !(uart[5] & 0x20) ); /* Wait for TXRDY */
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uart[0] = val;
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while( !(uart[5] & 0x20) ); /* Wait for TXRDY */
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local_irq_enable();
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return 1;
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}
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char getDebugChar(void)
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{
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volatile uint32_t *uart = (volatile uint32_t *)DEBUG_PORT_BASE;
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uint32_t val;
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while( !(uart[5] & 0x01) ); /* Wait for RXRDY */
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val = uart[0];
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return (char)val;
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}
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void initDebugPort(unsigned int uartclk, unsigned int baudrate)
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{
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unsigned int baud_divisor = (uartclk + 8 * baudrate)/(16 * baudrate);
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/* Enable FIFOs */
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writeb(UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
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UART_FCR_CLEAR_XMIT | UART_FCR_TRIGGER_4,
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(char *)DEBUG_PORT_BASE + (UART_FCR * 4));
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/* Select brtc divisor */
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writeb(UART_LCR_DLAB, (char *)DEBUG_PORT_BASE + (UART_LCR * 4));
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/* Store divisor lsb */
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writeb(baud_divisor, (char *)DEBUG_PORT_BASE + (UART_TX * 4));
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/* Store divisor msb */
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writeb(baud_divisor >> 8, (char *)DEBUG_PORT_BASE + (UART_IER * 4));
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/* Set 8N1 mode */
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writeb(UART_LCR_WLEN8, (char *)DEBUG_PORT_BASE + (UART_LCR * 4));
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/* Disable flow control */
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writeb(0, (char *)DEBUG_PORT_BASE + (UART_MCR * 4));
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/* Disable receive interrupt(!) */
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writeb(0, (char *)DEBUG_PORT_BASE + (UART_IER * 4));
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}
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#endif
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void __init msp_serial_setup(void)
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{
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char *s;
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char *endp;
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struct uart_port up;
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unsigned int uartclk;
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memset(&up, 0, sizeof(up));
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/* Check if clock was specified in environment */
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s = prom_getenv("uartfreqhz");
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if(!(s && *s && (uartclk = simple_strtoul(s, &endp, 10)) && *endp == 0))
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uartclk = MSP_BASE_BAUD;
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ppfinit("UART clock set to %d\n", uartclk);
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/* Initialize first serial port */
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up.mapbase = MSP_UART0_BASE;
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up.membase = ioremap_nocache(up.mapbase,MSP_UART_REG_LEN);
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up.irq = MSP_INT_UART0;
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up.uartclk = uartclk;
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up.regshift = 2;
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up.iotype = UPIO_DWAPB; /* UPIO_MEM like */
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up.flags = STD_COM_FLAGS;
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up.type = PORT_16550A;
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up.line = 0;
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up.private_data = (void*)UART0_STATUS_REG;
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if (early_serial_setup(&up))
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printk(KERN_ERR "Early serial init of port 0 failed\n");
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/* Initialize the second serial port, if one exists */
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switch (mips_machtype) {
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case MACH_MSP4200_EVAL:
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case MACH_MSP4200_GW:
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case MACH_MSP4200_FPGA:
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case MACH_MSP7120_EVAL:
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case MACH_MSP7120_GW:
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case MACH_MSP7120_FPGA:
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/* Enable UART1 on MSP4200 and MSP7120 */
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*GPIO_CFG2_REG = 0x00002299;
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#ifdef CONFIG_KGDB
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/* Initialize UART1 for kgdb since PMON doesn't */
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if( DEBUG_PORT_BASE == KSEG1ADDR(MSP_UART1_BASE) ) {
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if( mips_machtype == MACH_MSP4200_FPGA
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|| mips_machtype == MACH_MSP7120_FPGA )
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initDebugPort(uartclk,19200);
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else
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initDebugPort(uartclk,57600);
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}
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#endif
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break;
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default:
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return; /* No second serial port, good-bye. */
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}
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up.mapbase = MSP_UART1_BASE;
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up.membase = ioremap_nocache(up.mapbase,MSP_UART_REG_LEN);
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up.irq = MSP_INT_UART1;
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up.line = 1;
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up.private_data = (void*)UART1_STATUS_REG;
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if (early_serial_setup(&up))
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printk(KERN_ERR "Early serial init of port 1 failed\n");
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}
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@ -308,6 +308,7 @@ static unsigned int serial_in(struct uart_8250_port *up, int offset)
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return inb(up->port.iobase + 1);
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case UPIO_MEM:
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case UPIO_DWAPB:
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return readb(up->port.membase + offset);
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case UPIO_MEM32:
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@ -333,6 +334,8 @@ static unsigned int serial_in(struct uart_8250_port *up, int offset)
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static void
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serial_out(struct uart_8250_port *up, int offset, int value)
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{
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/* Save the offset before it's remapped */
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int save_offset = offset;
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offset = map_8250_out_reg(up, offset) << up->port.regshift;
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switch (up->port.iotype) {
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@ -359,6 +362,18 @@ serial_out(struct uart_8250_port *up, int offset, int value)
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writeb(value, up->port.membase + offset);
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break;
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case UPIO_DWAPB:
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/* Save the LCR value so it can be re-written when a
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* Busy Detect interrupt occurs. */
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if (save_offset == UART_LCR)
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up->lcr = value;
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writeb(value, up->port.membase + offset);
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/* Read the IER to ensure any interrupt is cleared before
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* returning from ISR. */
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if (save_offset == UART_TX || save_offset == UART_IER)
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value = serial_in(up, UART_IER);
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break;
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default:
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outb(value, up->port.iobase + offset);
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}
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@ -373,6 +388,7 @@ serial_out_sync(struct uart_8250_port *up, int offset, int value)
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#ifdef CONFIG_SERIAL_8250_AU1X00
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case UPIO_AU:
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#endif
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case UPIO_DWAPB:
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serial_out(up, offset, value);
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serial_in(up, UART_LCR); /* safe, no side-effects */
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break;
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@ -1388,6 +1404,19 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
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handled = 1;
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end = NULL;
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} else if (up->port.iotype == UPIO_DWAPB &&
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(iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
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/* The DesignWare APB UART has an Busy Detect (0x07)
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* interrupt meaning an LCR write attempt occured while the
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* UART was busy. The interrupt must be cleared by reading
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* the UART status register (USR) and the LCR re-written. */
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unsigned int status;
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status = *(volatile u32 *)up->port.private_data;
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serial_out(up, UART_LCR, up->lcr);
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handled = 1;
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end = NULL;
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} else if (end == NULL)
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end = l;
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@ -2090,6 +2119,7 @@ static int serial8250_request_std_resource(struct uart_8250_port *up)
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case UPIO_TSI:
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case UPIO_MEM32:
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case UPIO_MEM:
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case UPIO_DWAPB:
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if (!up->port.mapbase)
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break;
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@ -2127,6 +2157,7 @@ static void serial8250_release_std_resource(struct uart_8250_port *up)
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case UPIO_TSI:
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case UPIO_MEM32:
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case UPIO_MEM:
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case UPIO_DWAPB:
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if (!up->port.mapbase)
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break;
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@ -2064,6 +2064,7 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port)
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case UPIO_MEM32:
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case UPIO_AU:
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case UPIO_TSI:
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case UPIO_DWAPB:
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snprintf(address, sizeof(address),
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"MMIO 0x%lx", port->mapbase);
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break;
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@ -2409,6 +2410,7 @@ int uart_match_port(struct uart_port *port1, struct uart_port *port2)
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case UPIO_MEM32:
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case UPIO_AU:
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case UPIO_TSI:
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case UPIO_DWAPB:
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return (port1->mapbase == port2->mapbase);
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}
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return 0;
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@ -230,6 +230,7 @@ struct uart_port {
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#define UPIO_MEM32 (3)
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#define UPIO_AU (4) /* Au1x00 type IO */
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#define UPIO_TSI (5) /* Tsi108/109 type IO */
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#define UPIO_DWAPB (6) /* DesignWare APB UART */
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unsigned int read_status_mask; /* driver specific */
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unsigned int ignore_status_mask; /* driver specific */
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@ -276,6 +277,7 @@ struct uart_port {
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struct device *dev; /* parent device */
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unsigned char hub6; /* this should be in the 8250 driver */
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unsigned char unused[3];
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void *private_data; /* generic platform data pointer */
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};
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/*
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@ -38,6 +38,8 @@
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#define UART_IIR_RDI 0x04 /* Receiver data interrupt */
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#define UART_IIR_RLSI 0x06 /* Receiver line status interrupt */
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#define UART_IIR_BUSY 0x07 /* DesignWare APB Busy Detect */
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#define UART_FCR 2 /* Out: FIFO Control Register */
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#define UART_FCR_ENABLE_FIFO 0x01 /* Enable the FIFO */
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#define UART_FCR_CLEAR_RCVR 0x02 /* Clear the RCVR FIFO */
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