From: Zang Roy-r61911 The following patch gets rid of CONFIG_TSI108_BRIDGE. I add UPIO_TSI to handle IIR and IER register in serial_in and serial_out. (1) the reason to rewrite serial_in: TSI108 rev Z1 version ERRATA. Reading the UART's Interrupt Identification Register (IIR) clears the Transmit Holding Register Empty (THRE) and Transmit buffer Empty (TEMP) interrupts even if they are not enabled in the Interrupt Enable Register (IER). This leads to loss of the interrupts. Interrupts are not cleared when reading UART registers as 32-bit word. (2) the reason to rewrite serial_out: Check for UART_IER_UUE bit in the autoconfig routine. This section of autoconfig is excluded for Tsi108/109 because bits 7 and 6 are reserved for internal use. They are R/W bits. In addition to incorrect identification, changing these bits (from 00) will make Tsi108/109 UART non-functional. Cc: Russell King Signed-off-by: Andrew Morton --- drivers/serial/8250.c | 12 ++++++++++++ include/linux/serial_core.h | 1 + 2 files changed, 13 insertions(+) diff -puN drivers/serial/8250.c~serial-add-tsi108-8250-serial-support drivers/serial/8250.c --- a/drivers/serial/8250.c~serial-add-tsi108-8250-serial-support +++ a/drivers/serial/8250.c @@ -300,6 +300,7 @@ static inline int map_8250_out_reg(struc static unsigned int serial_in(struct uart_8250_port *up, int offset) { + unsigned int tmp; offset = map_8250_in_reg(up, offset) << up->port.regshift; switch (up->port.iotype) { @@ -318,6 +319,13 @@ static unsigned int serial_in(struct uar return __raw_readl(up->port.membase + offset); #endif + case UPIO_TSI: + if (offset == UART_IIR) { + tmp = readl((u32 *)(up->port.membase + UART_RX)); + return (cpu_to_le32(tmp) >> 8) & 0xff; + } else + return readb(up->port.membase + offset); + default: return inb(up->port.iobase + offset); } @@ -347,6 +355,10 @@ serial_out(struct uart_8250_port *up, in __raw_writel(value, up->port.membase + offset); break; #endif + case UPIO_TSI: + if (!((offset == UART_IER) && (value & UART_IER_UUE))) + writeb(value, up->port.membase + offset); + break; default: outb(value, up->port.iobase + offset); diff -puN include/linux/serial_core.h~serial-add-tsi108-8250-serial-support include/linux/serial_core.h --- a/include/linux/serial_core.h~serial-add-tsi108-8250-serial-support +++ a/include/linux/serial_core.h @@ -226,6 +226,7 @@ struct uart_port { #define UPIO_MEM (2) #define UPIO_MEM32 (3) #define UPIO_AU (4) /* Au1x00 type IO */ +#define UPIO_TSI (5) /* Tsi108/109 type IO */ unsigned int read_status_mask; /* driver specific */ unsigned int ignore_status_mask; /* driver specific */ _