linux/arch/mips/pmcs-msp71xx/msp_serial.c

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/*
* 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 <linux/slab.h>
#include <asm/bootinfo.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/serial.h>
#include <linux/serial_8250.h>
#include <msp_prom.h>
#include <msp_int.h>
#include <msp_regs.h>
struct msp_uart_data {
int last_lcr;
};
static void msp_serial_out(struct uart_port *p, int offset, int value)
{
struct msp_uart_data *d = p->private_data;
if (offset == UART_LCR)
d->last_lcr = value;
offset <<= p->regshift;
writeb(value, p->membase + offset);
}
static unsigned int msp_serial_in(struct uart_port *p, int offset)
{
offset <<= p->regshift;
return readb(p->membase + offset);
}
static int msp_serial_handle_irq(struct uart_port *p)
{
struct msp_uart_data *d = p->private_data;
unsigned int iir = readb(p->membase + (UART_IIR << p->regshift));
if (serial8250_handle_irq(p, iir)) {
return 1;
} else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
/*
* The DesignWare APB UART has an Busy Detect (0x07) interrupt
* meaning an LCR write attempt occurred while the UART was
* busy. The interrupt must be cleared by reading the UART
* status register (USR) and the LCR re-written.
*
* Note: MSP reserves 0x20 bytes of address space for the UART
* and the USR is mapped in a separate block at an offset of
* 0xc0 from the start of the UART.
*/
(void)readb(p->membase + 0xc0);
writeb(d->last_lcr, p->membase + (UART_LCR << p->regshift));
return 1;
}
return 0;
}
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_MEM;
up.flags = ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST;
up.type = PORT_16550A;
up.line = 0;
up.serial_out = msp_serial_out;
up.serial_in = msp_serial_in;
up.handle_irq = msp_serial_handle_irq;
up.private_data = kzalloc(sizeof(struct msp_uart_data), GFP_KERNEL);
if (!up.private_data) {
pr_err("failed to allocate uart private data\n");
return;
}
if (early_serial_setup(&up)) {
kfree(up.private_data);
pr_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;
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)) {
kfree(up.private_data);
pr_err("Early serial init of port 1 failed\n");
}
}