diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_of.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_of.c | 44 |
1 files changed, 42 insertions, 2 deletions
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c index 34f17a9785e7..9dcc17e33269 100644 --- a/drivers/tty/serial/8250/8250_of.c +++ b/drivers/tty/serial/8250/8250_of.c @@ -4,7 +4,10 @@ * * Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp. */ + +#include <linux/bits.h> #include <linux/console.h> +#include <linux/math.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/serial_core.h> @@ -25,6 +28,36 @@ struct of_serial_info { int line; }; +/* Nuvoton NPCM timeout register */ +#define UART_NPCM_TOR 7 +#define UART_NPCM_TOIE BIT(7) /* Timeout Interrupt Enable */ + +static int npcm_startup(struct uart_port *port) +{ + /* + * 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); + + return serial8250_do_startup(port); +} + +/* Nuvoton NPCM UARTs have a custom divisor calculation */ +static unsigned int npcm_get_divisor(struct uart_port *port, unsigned int baud, + unsigned int *frac) +{ + return DIV_ROUND_CLOSEST(port->uartclk, 16 * baud + 2) - 2; +} + +static int npcm_setup(struct uart_port *port) +{ + port->get_divisor = npcm_get_divisor; + port->startup = npcm_startup; + return 0; +} + /* * Fill a struct uart_port for a given device node */ @@ -164,10 +197,17 @@ static int of_platform_serial_setup(struct platform_device *ofdev, switch (type) { case PORT_RT2880: ret = rt288x_setup(port); - if (ret) - goto err_pmruntime; + break; + case PORT_NPCM: + ret = npcm_setup(port); + break; + default: + /* Nothing to do */ + ret = 0; break; } + if (ret) + goto err_pmruntime; if (IS_REACHABLE(CONFIG_SERIAL_8250_FSL) && (of_device_is_compatible(np, "fsl,ns16550") || |