On Thu, Feb 15, 2018 at 12:47:20PM +1030, Joel Stanley wrote: > 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. > > Signed-off-by: Joel Stanley <[email protected]> > Reviewed-by: Rob Herring <[email protected]> > --- > v2: > Remove redundant whitespace > Use port number 40 to fill in a gap > > Documentation/devicetree/bindings/serial/8250.txt | 1 + > drivers/tty/serial/8250/8250_of.c | 1 + > drivers/tty/serial/8250/8250_port.c | 29 > +++++++++++++++++++++++ > include/uapi/linux/serial_core.h | 3 +++ > include/uapi/linux/serial_reg.h | 5 ++++ > 5 files changed, 39 insertions(+) > > diff --git a/Documentation/devicetree/bindings/serial/8250.txt > b/Documentation/devicetree/bindings/serial/8250.txt > index dad3b2ec66d4..aeb6db4e35c3 100644 > --- a/Documentation/devicetree/bindings/serial/8250.txt > +++ b/Documentation/devicetree/bindings/serial/8250.txt > @@ -24,6 +24,7 @@ Required properties: > - "ti,da830-uart" > - "aspeed,ast2400-vuart" > - "aspeed,ast2500-vuart" > + - "nuvoton,npcm750-uart" > - "serial" if the port type is unknown. > - reg : offset and length of the register set for the device. > - interrupts : should contain uart interrupt. > 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 1328c7e70108..a72222f8b005 100644 > --- a/drivers/tty/serial/8250/8250_port.c > +++ b/drivers/tty/serial/8250/8250_port.c > @@ -293,6 +293,15 @@ 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 */ > @@ -2140,6 +2149,15 @@ 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 > @@ -2462,6 +2480,15 @@ 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) > @@ -2482,6 +2509,8 @@ 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); > > diff --git a/include/uapi/linux/serial_core.h > b/include/uapi/linux/serial_core.h > index 1c8413f93e3d..dce5f9dae121 100644 > --- a/include/uapi/linux/serial_core.h > +++ b/include/uapi/linux/serial_core.h > @@ -76,6 +76,9 @@ > #define PORT_SUNZILOG 38 > #define PORT_SUNSAB 39 > > +/* Nuvoton UART */ > +#define PORT_NPCM 40 > + > /* Intel EG20 */ > #define PORT_PCH_8LINE 44 > #define PORT_PCH_2LINE 45 > diff --git a/include/uapi/linux/serial_reg.h b/include/uapi/linux/serial_reg.h > index be07b5470f4b..f82f3c869df9 100644 > --- a/include/uapi/linux/serial_reg.h > +++ b/include/uapi/linux/serial_reg.h > @@ -376,5 +376,10 @@ > #define UART_ALTR_EN_TXFIFO_LW 0x01 /* Enable the TX FIFO Low > Watermark */ > #define UART_ALTR_TX_LOW 0x41 /* Tx FIFO Low Watermark */ > > + > +/* Nuvoton NPCM timeout register */ > +#define UART_NPCM_TOR 7 > +#define UART_NPCM_TOIE BIT(7) /* Timeout Interrupt Enable */
Why is this needed in a userspace api file? That feels very odd for just a new device. Please put this somewhere internal. thanks, greg k-h
