| Message ID | 20180212044810.23547-1-joel@jms.id.au |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | serial: 8250: Add Nuvoton NPCM UART | expand |
On Mon, Feb 12, 2018 at 6:48 AM, Joel Stanley <joel@jms.id.au> 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. > + [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, > + Redundant. > + }, > + /* > + * 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); > +/* Nuvoton NPCM UARTs have a custom divisor calculation */ > + return DIV_ROUND_CLOSEST(port->uartclk, 16 * baud + 2) - 2; Is there any link to datasheet? > +/* Nuvoton UART */ > +#define PORT_NPCM 118 We have gaps there. #40 is perfect place for this one. > +/* Nuvoton NPCM timeout register */ > +#define UART_NPCM_TOR 7 > +#define UART_NPCM_TOIE BIT(7) /* Timeout Interrupt Enable */
On Wed, Feb 14, 2018 at 3:22 AM, Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > On Mon, Feb 12, 2018 at 6:48 AM, Joel Stanley <joel@jms.id.au> 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. > > >> + [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, > >> + > > Redundant. You are referring to the extra whitespace? >> + }, > >> + /* >> + * 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); > >> +/* Nuvoton NPCM UARTs have a custom divisor calculation */ >> + return DIV_ROUND_CLOSEST(port->uartclk, 16 * baud + 2) - 2; > > Is there any link to datasheet? I have a copy of the datasheet under NDA. The Nuvoton guys might be able to help you out. Avi? > >> +/* Nuvoton UART */ >> +#define PORT_NPCM 118 > > We have gaps there. #40 is perfect place for this one. Ok, I will move it up. Thanks for the review. Cheers, Joel -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> From: joel.stan@gmail.com [mailto:joel.stan@gmail.com] On Behalf Of Joel Stanley > Sent: Thursday, February 15, 2018 4:00 AM > > On Wed, Feb 14, 2018 at 3:22 AM, Andy Shevchenko <andy.shevchenko@gmail.com> wrote: >> On Mon, Feb 12, 2018 at 6:48 AM, Joel Stanley <joel@jms.id.au> 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. >> >> >>> + [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, >> >>> + >> >> Redundant. > > You are referring to the extra whitespace? > >>> + }, >> >>> + /* >>> + * 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); >> >>> +/* Nuvoton NPCM UARTs have a custom divisor calculation */ >>> + return DIV_ROUND_CLOSEST(port->uartclk, 16 * baud + 2) - 2; >> >> Is there any link to datasheet? > > I have a copy of the datasheet under NDA. The Nuvoton guys might be able to help you out. Avi? In the spec the calculation is as follows: BaudOut = Selected UART Clock Source / ( 16 * [Divisor + 2] ) To translate it to our code is: baud = port->uartclk / (16 * (Divisor + 2) ) So it should calculate without the "+ 2" inside as follow: + return DIV_ROUND_CLOSEST(port->uartclk, 16 * baud) - 2; In order to get the spec you can add somthing like that: "For getting the NPCM7XX Data Sheet please contact bmc_marketing@nuvoton.com". BTW Andy, Intel has our Data Sheet under NDA, you can ask Mihm James <james.mihm@intel.com>. > >> >>> +/* Nuvoton UART */ >>> +#define PORT_NPCM 118 >> >> We have gaps there. #40 is perfect place for this one. > > Ok, I will move it up. Thanks for the review. > > Cheers, > > Joel > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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..c2e7fc111338 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -293,6 +293,16 @@ 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 +2150,15 @@ 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 +2481,15 @@ 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 +2510,8 @@ 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..3890ca4c5985 100644 --- a/include/uapi/linux/serial_core.h +++ b/include/uapi/linux/serial_core.h @@ -278,4 +278,7 @@ /* MediaTek BTIF */ #define PORT_MTK_BTIF 117 +/* Nuvoton UART */ +#define PORT_NPCM 118 + #endif /* _UAPILINUX_SERIAL_CORE_H */ 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 */ + #endif /* _LINUX_SERIAL_REG_H */
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 <joel@jms.id.au> --- Documentation/devicetree/bindings/serial/8250.txt | 1 + drivers/tty/serial/8250/8250_of.c | 1 + drivers/tty/serial/8250/8250_port.c | 30 +++++++++++++++++++++++ include/uapi/linux/serial_core.h | 3 +++ include/uapi/linux/serial_reg.h | 5 ++++ 5 files changed, 40 insertions(+)