All of lore.kernel.org
 help / color / mirror / Atom feed
From: Julien Masson <jmasson@baylibre.com>
To: Kevin Hilman <khilman@baylibre.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-serial@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Jiri Slaby <jslaby@suse.com>
Subject: [PATCH 1/2] tty: serial: meson_uart: Add support for kernel debugger
Date: Fri, 1 Feb 2019 08:36:59 +0100	[thread overview]
Message-ID: <864l9i1b0t.fsf@baylibre.com> (raw)

The kgdb invokes the poll_put_char and poll_get_char when communicating
with the host. This patch implement the serial polling hooks for the
meson_uart to be used for KGDB debugging over serial line.

Signed-off-by: Julien Masson <jmasson@baylibre.com>
---
 drivers/tty/serial/meson_uart.c | 46 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index 8a84259..49b20da 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -426,6 +426,48 @@ static void meson_uart_config_port(struct uart_port *port, int flags)
 	}
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context (i.e. kgdb).
+ */
+
+static int meson_uart_poll_get_char(struct uart_port *port)
+{
+	u32 c;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY)
+		c = NO_POLL_CHAR;
+	else
+		c = readl(port->membase + AML_UART_RFIFO);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return c;
+}
+
+static void meson_uart_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_EMPTY))
+		cpu_relax();
+
+	writel(c, port->membase + AML_UART_WFIFO);
+
+	while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_EMPTY))
+		cpu_relax();
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
 static const struct uart_ops meson_uart_ops = {
 	.set_mctrl      = meson_uart_set_mctrl,
 	.get_mctrl      = meson_uart_get_mctrl,
@@ -441,6 +483,10 @@ static const struct uart_ops meson_uart_ops = {
 	.request_port	= meson_uart_request_port,
 	.release_port	= meson_uart_release_port,
 	.verify_port	= meson_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= meson_uart_poll_get_char,
+	.poll_put_char	= meson_uart_poll_put_char,
+#endif
 };
 
 #ifdef CONFIG_SERIAL_MESON_CONSOLE
-- 
2.7.4


_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic

WARNING: multiple messages have this Message-ID (diff)
From: Julien Masson <jmasson@baylibre.com>
To: Kevin Hilman <khilman@baylibre.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-amlogic@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org,
	linux-serial@vger.kernel.org, Jiri Slaby <jslaby@suse.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 1/2] tty: serial: meson_uart: Add support for kernel debugger
Date: Fri, 1 Feb 2019 08:36:59 +0100	[thread overview]
Message-ID: <864l9i1b0t.fsf@baylibre.com> (raw)

The kgdb invokes the poll_put_char and poll_get_char when communicating
with the host. This patch implement the serial polling hooks for the
meson_uart to be used for KGDB debugging over serial line.

Signed-off-by: Julien Masson <jmasson@baylibre.com>
---
 drivers/tty/serial/meson_uart.c | 46 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index 8a84259..49b20da 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -426,6 +426,48 @@ static void meson_uart_config_port(struct uart_port *port, int flags)
 	}
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context (i.e. kgdb).
+ */
+
+static int meson_uart_poll_get_char(struct uart_port *port)
+{
+	u32 c;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY)
+		c = NO_POLL_CHAR;
+	else
+		c = readl(port->membase + AML_UART_RFIFO);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return c;
+}
+
+static void meson_uart_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_EMPTY))
+		cpu_relax();
+
+	writel(c, port->membase + AML_UART_WFIFO);
+
+	while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_EMPTY))
+		cpu_relax();
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
 static const struct uart_ops meson_uart_ops = {
 	.set_mctrl      = meson_uart_set_mctrl,
 	.get_mctrl      = meson_uart_get_mctrl,
@@ -441,6 +483,10 @@ static const struct uart_ops meson_uart_ops = {
 	.request_port	= meson_uart_request_port,
 	.release_port	= meson_uart_release_port,
 	.verify_port	= meson_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= meson_uart_poll_get_char,
+	.poll_put_char	= meson_uart_poll_put_char,
+#endif
 };
 
 #ifdef CONFIG_SERIAL_MESON_CONSOLE
-- 
2.7.4

WARNING: multiple messages have this Message-ID (diff)
From: Julien Masson <jmasson@baylibre.com>
To: Kevin Hilman <khilman@baylibre.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-serial@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Jiri Slaby <jslaby@suse.com>
Subject: [PATCH 1/2] tty: serial: meson_uart: Add support for kernel debugger
Date: Fri, 1 Feb 2019 08:36:59 +0100	[thread overview]
Message-ID: <864l9i1b0t.fsf@baylibre.com> (raw)

The kgdb invokes the poll_put_char and poll_get_char when communicating
with the host. This patch implement the serial polling hooks for the
meson_uart to be used for KGDB debugging over serial line.

Signed-off-by: Julien Masson <jmasson@baylibre.com>
---
 drivers/tty/serial/meson_uart.c | 46 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index 8a84259..49b20da 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -426,6 +426,48 @@ static void meson_uart_config_port(struct uart_port *port, int flags)
 	}
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context (i.e. kgdb).
+ */
+
+static int meson_uart_poll_get_char(struct uart_port *port)
+{
+	u32 c;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY)
+		c = NO_POLL_CHAR;
+	else
+		c = readl(port->membase + AML_UART_RFIFO);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return c;
+}
+
+static void meson_uart_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_EMPTY))
+		cpu_relax();
+
+	writel(c, port->membase + AML_UART_WFIFO);
+
+	while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_EMPTY))
+		cpu_relax();
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
 static const struct uart_ops meson_uart_ops = {
 	.set_mctrl      = meson_uart_set_mctrl,
 	.get_mctrl      = meson_uart_get_mctrl,
@@ -441,6 +483,10 @@ static const struct uart_ops meson_uart_ops = {
 	.request_port	= meson_uart_request_port,
 	.release_port	= meson_uart_release_port,
 	.verify_port	= meson_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= meson_uart_poll_get_char,
+	.poll_put_char	= meson_uart_poll_put_char,
+#endif
 };
 
 #ifdef CONFIG_SERIAL_MESON_CONSOLE
-- 
2.7.4


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

             reply	other threads:[~2019-02-05 16:02 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-01  7:36 Julien Masson [this message]
2019-02-01  7:36 ` [PATCH 1/2] tty: serial: meson_uart: Add support for kernel debugger Julien Masson
2019-02-01  7:36 ` Julien Masson
     [not found] <86h8dfx2jv.fsf@gmail.com>
2019-02-07 11:26 ` Julien Masson
2019-02-07 11:26   ` Julien Masson
2019-02-07 11:26   ` Julien Masson

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=864l9i1b0t.fsf@baylibre.com \
    --to=jmasson@baylibre.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jslaby@suse.com \
    --cc=khilman@baylibre.com \
    --cc=linux-amlogic@lists.infradead.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.