From: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
To: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Jiri Slaby" <jirislaby@kernel.org>,
"Andreas Färber" <afaerber@suse.de>,
"Manivannan Sadhasivam" <manivannan.sadhasivam@linaro.org>
Cc: linux-serial@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-actions@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 1/1] tty: serial: owl: Add support for kernel debugger
Date: Tue, 5 Jan 2021 19:02:02 +0200 [thread overview]
Message-ID: <036c09732183a30eaab230884114f65ca42ca3b9.1609865007.git.cristian.ciocaltea@gmail.com> (raw)
Implement 'poll_put_char' and 'poll_get_char' callbacks in struct
'owl_uart_ops' that enables OWL UART to be used for kernel debugging
over serial line.
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
---
Changes in v2:
- Reverted unnecessary changes per Andreas feedback
- Optimized implementation for 'owl_uart_poll_get_char()'
and 'owl_uart_poll_put_char()' callbacks
drivers/tty/serial/owl-uart.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/drivers/tty/serial/owl-uart.c b/drivers/tty/serial/owl-uart.c
index c149f8c30007..54b24669ebc5 100644
--- a/drivers/tty/serial/owl-uart.c
+++ b/drivers/tty/serial/owl-uart.c
@@ -12,6 +12,7 @@
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
@@ -461,6 +462,26 @@ static void owl_uart_config_port(struct uart_port *port, int flags)
}
}
+#ifdef CONFIG_CONSOLE_POLL
+
+static int owl_uart_poll_get_char(struct uart_port *port)
+{
+ if (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_RFEM)
+ return NO_POLL_CHAR;
+
+ return owl_uart_read(port, OWL_UART_RXDAT);
+}
+
+static void owl_uart_poll_put_char(struct uart_port *port, unsigned char ch)
+{
+ while (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU)
+ cpu_relax();
+
+ owl_uart_write(port, ch, OWL_UART_TXDAT);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
static const struct uart_ops owl_uart_ops = {
.set_mctrl = owl_uart_set_mctrl,
.get_mctrl = owl_uart_get_mctrl,
@@ -476,6 +497,10 @@ static const struct uart_ops owl_uart_ops = {
.request_port = owl_uart_request_port,
.release_port = owl_uart_release_port,
.verify_port = owl_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+ .poll_get_char = owl_uart_poll_get_char,
+ .poll_put_char = owl_uart_poll_put_char,
+#endif
};
#ifdef CONFIG_SERIAL_OWL_CONSOLE
--
2.30.0
next reply other threads:[~2021-01-05 17:03 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-05 17:02 Cristian Ciocaltea [this message]
2021-01-07 15:20 ` [PATCH v2 1/1] tty: serial: owl: Add support for kernel debugger Greg Kroah-Hartman
2021-01-07 18:16 ` Cristian Ciocaltea
2021-01-08 7:58 ` Jiri Slaby
2021-01-08 14:10 ` Cristian Ciocaltea
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