diff options
| author | Joel Stanley <joel@jms.id.au> | 2018-03-05 22:17:38 +1030 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-09 11:01:19 -0800 |
| commit | f597fbce38d230af95384f4a04e0a13a1d0ad45d (patch) | |
| tree | 0c92aa8862321fcde7d69aec0bb0035472f909d4 /drivers/tty | |
| parent | ca7c22fc9e8d16b11b8be81254d5f59c5a9f5bcf (diff) | |
| download | linux-f597fbce38d230af95384f4a04e0a13a1d0ad45d.tar.bz2 | |
serial: 8250: Add Nuvoton NPCM UART
The Nuvoton UART is almost compatible with the 8250 driver when probed
via the 8250_of driver, however it requires some extra configuration
at startup.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/8250/8250_of.c | 1 | ||||
| -rw-r--r-- | drivers/tty/serial/8250/8250_port.c | 33 |
2 files changed, 34 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c index 160b8906d9b9..9835b1c1cbe1 100644 --- a/drivers/tty/serial/8250/8250_of.c +++ b/drivers/tty/serial/8250/8250_of.c @@ -316,6 +316,7 @@ static const struct of_device_id of_platform_serial_table[] = { { .compatible = "mrvl,mmp-uart", .data = (void *)PORT_XSCALE, }, { .compatible = "ti,da830-uart", .data = (void *)PORT_DA830, }, + { .compatible = "nuvoton,npcm750-uart", .data = (void *)PORT_NPCM, }, { /* end of list */ }, }; MODULE_DEVICE_TABLE(of, of_platform_serial_table); diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index ffbb955d1c06..95833cbc4338 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -47,6 +47,10 @@ #define UART_EXAR_SLEEP 0x8b /* Sleep mode */ #define UART_EXAR_DVID 0x8d /* Device identification */ +/* Nuvoton NPCM timeout register */ +#define UART_NPCM_TOR 7 +#define UART_NPCM_TOIE BIT(7) /* Timeout Interrupt Enable */ + /* * Debugging. */ @@ -293,6 +297,15 @@ static const struct serial8250_config uart_config[] = { UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT, .flags = UART_CAP_FIFO, }, + [PORT_NPCM] = { + .name = "Nuvoton 16550", + .fifo_size = 16, + .tx_loadsz = 16, + .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 | + UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT, + .rxtrig_bytes = {1, 4, 8, 14}, + .flags = UART_CAP_FIFO, + }, }; /* Uart divisor latch read */ @@ -2141,6 +2154,15 @@ int serial8250_do_startup(struct uart_port *port) UART_DA830_PWREMU_MGMT_FREE); } + if (port->type == PORT_NPCM) { + /* + * Nuvoton calls the scratch register 'UART_TOR' (timeout + * register). Enable it, and set TIOC (timeout interrupt + * comparator) to be 0x20 for correct operation. + */ + serial_port_out(port, UART_NPCM_TOR, UART_NPCM_TOIE | 0x20); + } + #ifdef CONFIG_SERIAL_8250_RSA /* * If this is an RSA port, see if we can kick it up to the @@ -2463,6 +2485,15 @@ static unsigned int xr17v35x_get_divisor(struct uart_8250_port *up, return quot_16 >> 4; } +/* Nuvoton NPCM UARTs have a custom divisor calculation */ +static unsigned int npcm_get_divisor(struct uart_8250_port *up, + unsigned int baud) +{ + struct uart_port *port = &up->port; + + return DIV_ROUND_CLOSEST(port->uartclk, 16 * baud + 2) - 2; +} + static unsigned int serial8250_get_divisor(struct uart_8250_port *up, unsigned int baud, unsigned int *frac) @@ -2483,6 +2514,8 @@ static unsigned int serial8250_get_divisor(struct uart_8250_port *up, quot = 0x8002; else if (up->port.type == PORT_XR17V35X) quot = xr17v35x_get_divisor(up, baud, frac); + else if (up->port.type == PORT_NPCM) + quot = npcm_get_divisor(up, baud); else quot = uart_get_divisor(port, baud); |