On Wednesday 08 May 2013, Srinivas KANDAGATLA wrote:
> From: Srinivas Kandagatla <srinivas.kandagatla@xxxxxx>
> +*st-asc(Serial Port)
> +
> +Required properties:
> +- compatible : Should be "st,asc".
Are there any hardware revision numbers for the asc? If there are potentially
incompatible or backwards-compatible variants, it would be good to include
the version in this string.
> +- reg, reg-names, interrupts, interrupt-names : Standard way to define device
> + resources with names. look in
> + Documentation/devicetree/bindings/resource-names.txt
> +
> +Optional properties:
> +- st,hw-flow-ctrl bool flag to enable hardware flow control.
> +- st,force-m1 bool flat to force asc to be in Mode-1 recommeded
> + for high bit rates (above 19.2K)
> +Example:
> +serial@fe440000{
> + compatible = "st,asc";
> + reg = <0xfe440000 0x2c>;
> + interrupts = <0 209 0>;
> +};
I would also recommed adding a way to set the default baud rate through
a property. Following the example of the 8250 driver, you should probably
call that "current-speed".
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index 7e7006f..346f325 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -1484,6 +1484,25 @@ config SERIAL_RP2_NR_UARTS
> If multiple cards are present, the default limit of 32 ports may
> need to be increased.
>
> +config SERIAL_ST_ASC
> + tristate "ST ASC serial port support"
> + depends on PLAT_STIXXXX
> + default y
> + select SERIAL_CORE
> + help
> + This driver is for the on-chip Asychronous Serial Controller on
> + STMicroelectronics STixxxx SoCs.
> + ASC is embedded in ST COMMS IP block. It supports Rx & Tx functionality.
> + It support all industry standard baud rates.
> +
> + If unsure, say N.
I would not make it "default y".
> +config SERIAL_ST_ASC_CONSOLE
> + bool "Support for console on ST ASC"
> + depends on SERIAL_ST_ASC
> + default y
> + select SERIAL_CORE_CONSOLE
> +
> endmenu
This needs to be "depends on SERIAL_ST_ASC=y". You would get a link error
if you try to make SERIAL_ST_ASC a loadable module and SERIAL_ST_ASC_CONSOLE
built-in.
> +
> +static struct asc_port asc_ports[ASC_MAX_PORTS];
> +static struct uart_driver asc_uart_driver;
> +
> +/*---- Forward function declarations---------------------------*/
> +static irqreturn_t asc_interrupt(int irq, void *ptr);
> +static void asc_transmit_chars(struct uart_port *);
> +static int asc_set_baud(struct asc_port *ascport, int baud);
> +
Please remove all forward declarations, by reordering the functions in
the way they are called.
> diff --git a/drivers/tty/serial/st-asc.h b/drivers/tty/serial/st-asc.h
> new file mode 100644
> index 0000000..e59f818
> --- /dev/null
> +++ b/drivers/tty/serial/st-asc.h
> +#ifndef _ST_ASC_H
> +#define _ST_ASC_H
> +
> +#include <linux/serial_core.h>
> +#include <linux/clk.h>
> +
> +struct asc_port {
> + struct uart_port port;
> + struct clk *clk;
> + unsigned int hw_flow_control:1;
> + unsigned int check_parity:1;
> + unsigned int force_m1:1;
> +};
Since this header file is only used in one place, just merge it into
the driver itself.
> +#define ASC_MAJOR 204
> +#define ASC_MINOR_START 40
I don't know what the current policy is on allocating major/minor numbers,
but I'm sure you cannot just reuse one that is already used.
Documentation/devices.txt lists the ones that are officially assigned.
Can't you use dynamic allocation here?
Arnd
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