[PATCHv2,07/11] serdev: add helpers for cts and rts handling
diff mbox series

Message ID 20170321223216.11733-8-sre@kernel.org
State New, archived
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Series
  • Nokia H4+ support
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Commit Message

Sebastian Reichel March 21, 2017, 10:32 p.m. UTC
Add serdev helper functions for handling of cts and rts
lines using the serdev's tiocm functions.

Signed-off-by: Sebastian Reichel <sre@kernel.org>
---
 include/linux/serdev.h | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

Comments

Rob Herring March 22, 2017, 9:03 p.m. UTC | #1
On Tue, Mar 21, 2017 at 5:32 PM, Sebastian Reichel <sre@kernel.org> wrote:
> Add serdev helper functions for handling of cts and rts
> lines using the serdev's tiocm functions.
>
> Signed-off-by: Sebastian Reichel <sre@kernel.org>
> ---
>  include/linux/serdev.h | 31 +++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
>
> diff --git a/include/linux/serdev.h b/include/linux/serdev.h
> index 3ad1d695f947..8cdce2ea0d51 100644
> --- a/include/linux/serdev.h
> +++ b/include/linux/serdev.h
> @@ -16,6 +16,7 @@
>  #include <linux/types.h>
>  #include <linux/device.h>
>  #include <asm-generic/termios.h>
> +#include <linux/delay.h>
>
>  struct serdev_controller;
>  struct serdev_device;
> @@ -254,6 +255,36 @@ static inline int serdev_device_write_room(struct serdev_device *sdev)
>
>  #endif /* CONFIG_SERIAL_DEV_BUS */
>
> +static inline bool serdev_device_get_cts(struct serdev_device *serdev)
> +{
> +       int status = serdev_device_get_tiocm(serdev);
> +       return !!(status & TIOCM_CTS);
> +}
> +
> +static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms)
> +{
> +       unsigned long timeout;
> +       bool signal;
> +
> +       timeout = jiffies + msecs_to_jiffies(timeout_ms);
> +       while (!time_after(jiffies, timeout)) {

You can use time_is_after_jiffies(timeout) instead of !time_after.

> +               signal = serdev_device_get_cts(serdev);
> +               if (signal == state)
> +                       return 0;
> +               usleep_range(1000, 2000);
> +       }
> +
> +       return -ETIMEDOUT;
> +}
> +
> +static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable)
> +{
> +       if (enable)
> +               return serdev_device_set_tiocm(serdev, TIOCM_OUT2 | TIOCM_RTS, 0);

Perhaps a comment why we're messing with OUT2.

With those,

Acked-by: Rob Herring <robh@kernel.org>

> +       else
> +               return serdev_device_set_tiocm(serdev, 0, TIOCM_OUT2 | TIOCM_RTS);
> +}
> +
>  /*
>   * serdev hooks into TTY core
>   */
> --
> 2.11.0
>

Patch
diff mbox series

diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index 3ad1d695f947..8cdce2ea0d51 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -16,6 +16,7 @@ 
 #include <linux/types.h>
 #include <linux/device.h>
 #include <asm-generic/termios.h>
+#include <linux/delay.h>
 
 struct serdev_controller;
 struct serdev_device;
@@ -254,6 +255,36 @@  static inline int serdev_device_write_room(struct serdev_device *sdev)
 
 #endif /* CONFIG_SERIAL_DEV_BUS */
 
+static inline bool serdev_device_get_cts(struct serdev_device *serdev)
+{
+	int status = serdev_device_get_tiocm(serdev);
+	return !!(status & TIOCM_CTS);
+}
+
+static inline int serdev_device_wait_for_cts(struct serdev_device *serdev, bool state, int timeout_ms)
+{
+	unsigned long timeout;
+	bool signal;
+
+	timeout = jiffies + msecs_to_jiffies(timeout_ms);
+	while (!time_after(jiffies, timeout)) {
+		signal = serdev_device_get_cts(serdev);
+		if (signal == state)
+			return 0;
+		usleep_range(1000, 2000);
+	}
+
+	return -ETIMEDOUT;
+}
+
+static inline int serdev_device_set_rts(struct serdev_device *serdev, bool enable)
+{
+	if (enable)
+		return serdev_device_set_tiocm(serdev, TIOCM_OUT2 | TIOCM_RTS, 0);
+	else
+		return serdev_device_set_tiocm(serdev, 0, TIOCM_OUT2 | TIOCM_RTS);
+}
+
 /*
  * serdev hooks into TTY core
  */