diff options
Diffstat (limited to 'arch/mips/pmcs-msp71xx/msp_serial.c')
| -rw-r--r-- | arch/mips/pmcs-msp71xx/msp_serial.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/arch/mips/pmcs-msp71xx/msp_serial.c b/arch/mips/pmcs-msp71xx/msp_serial.c new file mode 100644 index 00000000000..d304be22b96 --- /dev/null +++ b/arch/mips/pmcs-msp71xx/msp_serial.c @@ -0,0 +1,154 @@ +/* + * 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"); + } +} |