From 4539c24fe4f92c09ee668ef959d3e8180df619b9 Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Tue, 17 May 2011 16:12:36 -0600 Subject: [PATCH] tty/serial: Add explicit PORT_TEGRA type Tegra's UART is currently auto-detected as PORT_XSCALE due to register bit UART_IER.UUE being writable. However, the Tegra documentation states that this register bit is reserved. Hence, we should not program it. Instead, the documentation specifies that the UART is 16550 compatible. However, Tegra does need register bit UART_IER.RTOIE set, which is not enabled by any 16550 port type. This was not noticed before, since PORT_XSCALE enables CAP_UUE, which conflates both UUE and RTOIE bit programming. This change defines PORT_TEGRA that doesn't set UART_CAP_UUE, but does set UART_CAP_RTOIE, which is a new capability indicating that the RTOIE bit needs to be enabled. Based-on-code-by: Laxman Dewangan Cc: Laxman Dewangan Signed-off-by: Stephen Warren Acked-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250.c | 14 ++++++++++++-- drivers/tty/serial/8250.h | 1 + include/linux/serial_core.h | 3 ++- include/linux/serial_reg.h | 1 + 4 files changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c index 54482d724fee..a5e290de8c93 100644 --- a/drivers/tty/serial/8250.c +++ b/drivers/tty/serial/8250.c @@ -271,7 +271,7 @@ static const struct serial8250_config uart_config[] = { .fifo_size = 32, .tx_loadsz = 32, .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, - .flags = UART_CAP_FIFO | UART_CAP_UUE, + .flags = UART_CAP_FIFO | UART_CAP_UUE | UART_CAP_RTOIE, }, [PORT_RM9000] = { .name = "RM9000", @@ -301,6 +301,14 @@ static const struct serial8250_config uart_config[] = { .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_CAP_AFE, }, + [PORT_TEGRA] = { + .name = "Tegra", + .fifo_size = 32, + .tx_loadsz = 8, + .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 | + UART_FCR_T_TRIG_01, + .flags = UART_CAP_FIFO | UART_CAP_RTOIE, + }, }; #if defined(CONFIG_MIPS_ALCHEMY) @@ -2403,7 +2411,9 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, UART_ENABLE_MS(&up->port, termios->c_cflag)) up->ier |= UART_IER_MSI; if (up->capabilities & UART_CAP_UUE) - up->ier |= UART_IER_UUE | UART_IER_RTOIE; + up->ier |= UART_IER_UUE; + if (up->capabilities & UART_CAP_RTOIE) + up->ier |= UART_IER_RTOIE; serial_out(up, UART_IER, up->ier); diff --git a/drivers/tty/serial/8250.h b/drivers/tty/serial/8250.h index d13b586c0f72..6edf4a6a22d4 100644 --- a/drivers/tty/serial/8250.h +++ b/drivers/tty/serial/8250.h @@ -42,6 +42,7 @@ struct serial8250_config { #define UART_CAP_SLEEP (1 << 10) /* UART has IER sleep */ #define UART_CAP_AFE (1 << 11) /* MCR-based hw flow control */ #define UART_CAP_UUE (1 << 12) /* UART needs IER bit 6 set (Xscale) */ +#define UART_CAP_RTOIE (1 << 13) /* UART needs IER bit 4 set (Xscale, Tegra) */ #define UART_BUG_QUOT (1 << 0) /* UART has buggy quot LSB */ #define UART_BUG_TXEN (1 << 1) /* UART has buggy TX IIR status */ diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 95d479ba514e..a5c31146a337 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -45,7 +45,8 @@ #define PORT_OCTEON 17 /* Cavium OCTEON internal UART */ #define PORT_AR7 18 /* Texas Instruments AR7 internal UART */ #define PORT_U6_16550A 19 /* ST-Ericsson U6xxx internal UART */ -#define PORT_MAX_8250 19 /* max port ID */ +#define PORT_TEGRA 20 /* NVIDIA Tegra internal UART */ +#define PORT_MAX_8250 20 /* max port ID */ /* * ARM specific type numbers. These are not currently guaranteed diff --git a/include/linux/serial_reg.h b/include/linux/serial_reg.h index 3ecb71a9e505..5f66e8499fb9 100644 --- a/include/linux/serial_reg.h +++ b/include/linux/serial_reg.h @@ -57,6 +57,7 @@ * ST16C654: 8 16 56 60 8 16 32 56 PORT_16654 * TI16C750: 1 16 32 56 xx xx xx xx PORT_16750 * TI16C752: 8 16 56 60 8 16 32 56 + * Tegra: 1 4 8 14 16 8 4 1 PORT_TEGRA */ #define UART_FCR_R_TRIG_00 0x00 #define UART_FCR_R_TRIG_01 0x40 -- 2.20.1