[PATCH] powerpc: Modem control lines support for the cpm_uart driver
Laurent Pinchart
laurentp at cse-semaphore.com
Wed Apr 16 19:10:20 EST 2008
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.
Signed-off-by: Laurent Pinchart <laurentp at cse-semaphore.com>
---
Documentation/powerpc/booting-without-of.txt | 10 ++++++
drivers/serial/cpm_uart/cpm_uart.h | 10 ++++++
drivers/serial/cpm_uart/cpm_uart_core.c | 40 ++++++++++++++++++++++++--
3 files changed, 57 insertions(+), 3 deletions(-)
diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt
index 1e5572a..012f231 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
@@ -1976,6 +1976,14 @@ platforms are moved over to use the flattened-device-tree model.
- fsl,cpm2-scc-uart
- fsl,qe-uart
+ Modem control lines connected to GPIO controllers are listed in the
+ gpios property as described in section VIII.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 at 11a00 {
@@ -1987,6 +1995,8 @@ platforms are moved over to use the flattened-device-tree model.
interrupt-parent = <&PIC>;
fsl,cpm-brg = <1>;
fsl,cpm-command = <00800000>;
+ gpios = <&gpio_c 15 0
+ &gpio_d 29 0>;
};
iii) Network
diff --git a/drivers/serial/cpm_uart/cpm_uart.h b/drivers/serial/cpm_uart/cpm_uart.h
index 0cc39f8..d0c55e2 100644
--- a/drivers/serial/cpm_uart/cpm_uart.h
+++ b/drivers/serial/cpm_uart/cpm_uart.h
@@ -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];
};
#ifndef CONFIG_PPC_CPM_NEW_BINDING
diff --git a/drivers/serial/cpm_uart/cpm_uart_core.c b/drivers/serial/cpm_uart/cpm_uart_core.c
index 7a704ff..0f08071 100644
--- a/drivers/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/serial/cpm_uart/cpm_uart_core.c
@@ -42,6 +42,8 @@
#include <linux/bootmem.h>
#include <linux/dma-mapping.h>
#include <linux/fs_uart_pd.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
#include <asm/io.h>
#include <asm/irq.h>
@@ -152,13 +154,41 @@ 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;
}
/*
@@ -959,6 +989,7 @@ 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) {
@@ -1017,6 +1048,9 @@ 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:
--
1.5.0
--
Laurent Pinchart
CSE Semaphore Belgium
Chaussee de Bruxelles, 732A
B-1410 Waterloo
Belgium
T +32 (2) 387 42 59
F +32 (2) 387 42 75
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