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cpm_uart: Modem control lines support 

This patch replaces the get_mctrl/set_mctrl stubs with modem control line
read/write access through the GPIO lib.

Available modem control lines are described in the device tree using GPIO
bindings. The driver expect a GPIO pin for each of the CTS, RTS, DCD, DSR,
DTR and RI signals. Unused control lines can be left out.

Signed-off-by: Laurent Pinchart <laurentp@cse-semaphore.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
hifive-unleashed-5.1
Laurent Pinchart 2008-07-24 18:36:37 +02:00 committed by Kumar Gala
parent dc2380ec85
commit 7485d26b7e
3 changed files with 58 additions and 3 deletions
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11
Documentation/powerpc/dts-bindings/fsl/cpm_qe/serial.txt
View File

@ -7,6 +7,15 @@ Currently defined compatibles:
- fsl,cpm2-scc-uart
- fsl,qe-uart
Modem control lines connected to GPIO controllers are listed in the gpios
property as described in booting-without-of.txt, section IX.1 in the following
order:
CTS, RTS, DCD, DSR, DTR, and RI.
The gpios property is optional and can be left out when control lines are
not used.
Example:
serial@11a00 {
@ -18,4 +27,6 @@ Example:
interrupt-parent = <&PIC>;
fsl,cpm-brg = <1>;
fsl,cpm-command = <00800000>;
gpios = <&gpio_c 15 0
&gpio_d 29 0>;
};

10
drivers/serial/cpm_uart/cpm_uart.h
View File

@ -50,6 +50,15 @@
#define SCC_WAIT_CLOSING 100
#define GPIO_CTS 0
#define GPIO_RTS 1
#define GPIO_DCD 2
#define GPIO_DSR 3
#define GPIO_DTR 4
#define GPIO_RI 5
#define NUM_GPIOS (GPIO_RI+1)
struct uart_cpm_port {
struct uart_port port;
u16 rx_nrfifos;
@ -82,6 +91,7 @@ struct uart_cpm_port {
int wait_closing;
/* value to combine with opcode to form cpm command */
u32 command;
int gpios[NUM_GPIOS];
};
extern int cpm_uart_nr;

40
drivers/serial/cpm_uart/cpm_uart_core.c
View File

@ -43,6 +43,8 @@
#include <linux/dma-mapping.h>
#include <linux/fs_uart_pd.h>
#include <linux/of_platform.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <asm/io.h>
#include <asm/irq.h>
@ -96,13 +98,41 @@ static unsigned int cpm_uart_tx_empty(struct uart_port *port)
static void cpm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
/* Whee. Do nothing. */
struct uart_cpm_port *pinfo = (struct uart_cpm_port *)port;
if (pinfo->gpios[GPIO_RTS] >= 0)
gpio_set_value(pinfo->gpios[GPIO_RTS], !(mctrl & TIOCM_RTS));
if (pinfo->gpios[GPIO_DTR] >= 0)
gpio_set_value(pinfo->gpios[GPIO_DTR], !(mctrl & TIOCM_DTR));
}
static unsigned int cpm_uart_get_mctrl(struct uart_port *port)
{
/* Whee. Do nothing. */
return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
struct uart_cpm_port *pinfo = (struct uart_cpm_port *)port;
unsigned int mctrl = TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
if (pinfo->gpios[GPIO_CTS] >= 0) {
if (gpio_get_value(pinfo->gpios[GPIO_CTS]))
mctrl &= ~TIOCM_CTS;
}
if (pinfo->gpios[GPIO_DSR] >= 0) {
if (gpio_get_value(pinfo->gpios[GPIO_DSR]))
mctrl &= ~TIOCM_DSR;
}
if (pinfo->gpios[GPIO_DCD] >= 0) {
if (gpio_get_value(pinfo->gpios[GPIO_DCD]))
mctrl &= ~TIOCM_CAR;
}
if (pinfo->gpios[GPIO_RI] >= 0) {
if (!gpio_get_value(pinfo->gpios[GPIO_RI]))
mctrl |= TIOCM_RNG;
}
return mctrl;
}
/*
@ -991,6 +1021,7 @@ static int cpm_uart_init_port(struct device_node *np,
void __iomem *mem, *pram;
int len;
int ret;
int i;
data = of_get_property(np, "fsl,cpm-brg", &len);
if (!data || len != 4) {
@ -1050,6 +1081,9 @@ static int cpm_uart_init_port(struct device_node *np,
goto out_pram;
}
for (i = 0; i < NUM_GPIOS; i++)
pinfo->gpios[i] = of_get_gpio(np, i);
return cpm_uart_request_port(&pinfo->port);
out_pram: