diff options
| -rw-r--r-- | arch/mips/pmc-sierra/msp71xx/msp_serial.c | 69 |
1 files changed, 65 insertions, 4 deletions
diff --git a/arch/mips/pmc-sierra/msp71xx/msp_serial.c b/arch/mips/pmc-sierra/msp71xx/msp_serial.c index c3247b5801f..a1c7c7da233 100644 --- a/arch/mips/pmc-sierra/msp71xx/msp_serial.c +++ b/arch/mips/pmc-sierra/msp71xx/msp_serial.c @@ -27,6 +27,7 @@ #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> @@ -38,6 +39,55 @@ #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; @@ -59,13 +109,22 @@ void __init msp_serial_setup(void) up.irq = MSP_INT_UART0; up.uartclk = uartclk; up.regshift = 2; - up.iotype = UPIO_DWAPB; /* UPIO_MEM like */ + up.iotype = UPIO_MEM; up.flags = ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST; up.type = PORT_16550A; up.line = 0; - up.private_data = (void*)UART0_STATUS_REG; - if (early_serial_setup(&up)) + 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) { @@ -88,6 +147,8 @@ void __init msp_serial_setup(void) up.irq = MSP_INT_UART1; up.line = 1; up.private_data = (void*)UART1_STATUS_REG; - if (early_serial_setup(&up)) + if (early_serial_setup(&up)) { + kfree(up.private_data); pr_err("Early serial init of port 1 failed\n"); + } } |