diff options
| -rw-r--r-- | drivers/tty/serial/8250/8250_uniphier.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/drivers/tty/serial/8250/8250_uniphier.c b/drivers/tty/serial/8250/8250_uniphier.c index 633ac378b7f2..97a45b798fcd 100644 --- a/drivers/tty/serial/8250/8250_uniphier.c +++ b/drivers/tty/serial/8250/8250_uniphier.c @@ -29,12 +29,13 @@ * - MMIO32 (regshift = 2) * - FCR is not at 2, but 3 * - LCR and MCR are not at 3 and 4, they share 4 + * - No SCR (Instead, CHAR can be used as a scratch register) * - Divisor latch at 9, no divisor latch access bit */ #define UNIPHIER_UART_REGSHIFT 2 -/* bit[15:8] = CHAR (not used), bit[7:0] = FCR */ +/* bit[15:8] = CHAR, bit[7:0] = FCR */ #define UNIPHIER_UART_CHAR_FCR (3 << (UNIPHIER_UART_REGSHIFT)) /* bit[15:8] = LCR, bit[7:0] = MCR */ #define UNIPHIER_UART_LCR_MCR (4 << (UNIPHIER_UART_REGSHIFT)) @@ -72,13 +73,18 @@ OF_EARLYCON_DECLARE(uniphier, "socionext,uniphier-uart", /* * The register map is slightly different from that of 8250. - * IO callbacks must be overridden for correct access to FCR, LCR, and MCR. + * IO callbacks must be overridden for correct access to FCR, LCR, MCR and SCR. */ static unsigned int uniphier_serial_in(struct uart_port *p, int offset) { unsigned int valshift = 0; switch (offset) { + case UART_SCR: + /* No SCR for this hardware. Use CHAR as a scratch register */ + valshift = 8; + offset = UNIPHIER_UART_CHAR_FCR; + break; case UART_LCR: valshift = 8; /* fall through */ @@ -91,8 +97,8 @@ static unsigned int uniphier_serial_in(struct uart_port *p, int offset) } /* - * The return value must be masked with 0xff because LCR and MCR reside - * in the same register that must be accessed by 32-bit write/read. + * The return value must be masked with 0xff because some registers + * share the same offset that must be accessed by 32-bit write/read. * 8 or 16 bit access to this hardware result in unexpected behavior. */ return (readl(p->membase + offset) >> valshift) & 0xff; @@ -101,9 +107,13 @@ static unsigned int uniphier_serial_in(struct uart_port *p, int offset) static void uniphier_serial_out(struct uart_port *p, int offset, int value) { unsigned int valshift = 0; - bool normal = true; + bool normal = false; switch (offset) { + case UART_SCR: + /* No SCR for this hardware. Use CHAR as a scratch register */ + valshift = 8; + /* fall through */ case UART_FCR: offset = UNIPHIER_UART_CHAR_FCR; break; @@ -114,10 +124,10 @@ static void uniphier_serial_out(struct uart_port *p, int offset, int value) /* fall through */ case UART_MCR: offset = UNIPHIER_UART_LCR_MCR; - normal = false; break; default: offset <<= UNIPHIER_UART_REGSHIFT; + normal = true; break; } |