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Diffstat (limited to 'arch/mips/pmc-sierra/msp71xx/msp_serial.c')
-rw-r--r--arch/mips/pmc-sierra/msp71xx/msp_serial.c73
1 files changed, 67 insertions, 6 deletions
diff --git a/arch/mips/pmc-sierra/msp71xx/msp_serial.c b/arch/mips/pmc-sierra/msp71xx/msp_serial.c
index f7261628d8a..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))
- printk(KERN_ERR "Early serial init of port 0 failed\n");
+ 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))
- printk(KERN_ERR "Early serial init of port 1 failed\n");
+ if (early_serial_setup(&up)) {
+ kfree(up.private_data);
+ pr_err("Early serial init of port 1 failed\n");
+ }
}