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imx6: kernel: Backport serial port fixes

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Signed-off-by: Petr Štetiar <ynezz@true.cz>
This commit is contained in:
Petr Štetiar 2017-01-13 11:42:08 +01:00 committed by John Crispin
parent 1708644f19
commit 26e4fee6e2
4 changed files with 249 additions and 0 deletions
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78
target/linux/imx6/patches-4.4/110-serial-imx-repair-and-complete-handshaking.patch Normal file
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@ -0,0 +1,78 @@
From 90ebc4838666d148eac5bbac6f4044e5b25cd2d6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Sun, 18 Oct 2015 21:34:46 +0200
Subject: [PATCH] serial: imx: repair and complete handshaking
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
The .get_mctrl callback should not report the status of RTS or LOOP, so
drop this. Instead implement reporting the state of CAR (aka DCD) and
RI.
For .set_mctrl implement setting the DTR line.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Petr Štetiar <ynezz@true.cz>
---
drivers/tty/serial/imx.c | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 76818f5..086675e 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -148,8 +148,11 @@
#define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
#define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
#define USR2_IDLE (1<<12) /* Idle condition */
+#define USR2_RIDELT (1<<10) /* Ring Interrupt Delta */
+#define USR2_RIIN (1<<9) /* Ring Indicator Input */
#define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
#define USR2_WAKE (1<<7) /* Wake */
+#define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
#define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
#define USR2_TXDC (1<<3) /* Transmitter complete */
#define USR2_BRCD (1<<2) /* Break condition */
@@ -804,16 +807,19 @@ static unsigned int imx_tx_empty(struct uart_port *port)
static unsigned int imx_get_mctrl(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
- unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
+ unsigned int tmp = TIOCM_DSR;
+ unsigned usr1 = readl(sport->port.membase + USR1);
- if (readl(sport->port.membase + USR1) & USR1_RTSS)
+ if (usr1 & USR1_RTSS)
tmp |= TIOCM_CTS;
- if (readl(sport->port.membase + UCR2) & UCR2_CTS)
- tmp |= TIOCM_RTS;
+ /* in DCE mode DCDIN is always 0 */
+ if (!(usr1 & USR2_DCDIN))
+ tmp |= TIOCM_CAR;
- if (readl(sport->port.membase + uts_reg(sport)) & UTS_LOOP)
- tmp |= TIOCM_LOOP;
+ /* in DCE mode RIIN is always 0 */
+ if (readl(sport->port.membase + USR2) & USR2_RIIN)
+ tmp |= TIOCM_RI;
return tmp;
}
@@ -831,6 +837,11 @@ static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
writel(temp, sport->port.membase + UCR2);
}
+ temp = readl(sport->port.membase + UCR3) & ~UCR3_DSR;
+ if (!(mctrl & TIOCM_DTR))
+ temp |= UCR3_DSR;
+ writel(temp, sport->port.membase + UCR3);
+
temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
if (mctrl & TIOCM_LOOP)
temp |= UTS_LOOP;
--
1.9.1

38
target/linux/imx6/patches-4.4/111-serial-imx-fix-polarity-of-RI.patch Normal file
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@ -0,0 +1,38 @@
From 9a061cea4477f26a1dfcc0a08dc20575016e91df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Thu, 24 Mar 2016 14:24:20 +0100
Subject: [PATCH 1/3] serial: imx: fix polarity of RI
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
When in DTE mode, the bit USR2_RIIN is active low. So invert the logic
accordingly.
Fixes: 90ebc4838666 ("serial: imx: repair and complete handshaking")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Petr Štetiar <ynezz@true.cz>
---
drivers/tty/serial/imx.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 231e7d5..bfc4555 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -797,9 +797,9 @@ static unsigned int imx_get_hwmctrl(struct imx_port *sport)
if (!(usr1 & USR2_DCDIN))
tmp |= TIOCM_CAR;
- /* in DCE mode RIIN is always 0 */
- if (readl(sport->port.membase + USR2) & USR2_RIIN)
- tmp |= TIOCM_RI;
+ if (sport->dte_mode)
+ if (!(readl(sport->port.membase + USR2) & USR2_RIIN))
+ tmp |= TIOCM_RI;
return tmp;
}
--
1.9.1

72
target/linux/imx6/patches-4.4/112-serial-imx-let-irq-handler-return-IRQ_NONE-if-no-eve.patch Normal file
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From de4356da2cd1a1857513047997d81143cb95a4e1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Thu, 24 Mar 2016 14:24:21 +0100
Subject: [PATCH 2/3] serial: imx: let irq handler return IRQ_NONE if no event
was handled
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
This gives the irq core a chance to disable the serial interrupt in case
an event isn't cleared in the handler.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Petr Štetiar <ynezz@true.cz>
---
drivers/tty/serial/imx.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index bfc4555..5ced61e 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -734,6 +734,7 @@ static irqreturn_t imx_int(int irq, void *dev_id)
struct imx_port *sport = dev_id;
unsigned int sts;
unsigned int sts2;
+ irqreturn_t ret = IRQ_NONE;
sts = readl(sport->port.membase + USR1);
sts2 = readl(sport->port.membase + USR2);
@@ -743,26 +744,34 @@ static irqreturn_t imx_int(int irq, void *dev_id)
imx_dma_rxint(sport);
else
imx_rxint(irq, dev_id);
+ ret = IRQ_HANDLED;
}
if ((sts & USR1_TRDY &&
readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN) ||
(sts2 & USR2_TXDC &&
- readl(sport->port.membase + UCR4) & UCR4_TCEN))
+ readl(sport->port.membase + UCR4) & UCR4_TCEN)) {
imx_txint(irq, dev_id);
+ ret = IRQ_HANDLED;
+ }
- if (sts & USR1_RTSD)
+ if (sts & USR1_RTSD) {
imx_rtsint(irq, dev_id);
+ ret = IRQ_HANDLED;
+ }
- if (sts & USR1_AWAKE)
+ if (sts & USR1_AWAKE) {
writel(USR1_AWAKE, sport->port.membase + USR1);
+ ret = IRQ_HANDLED;
+ }
if (sts2 & USR2_ORE) {
sport->port.icount.overrun++;
writel(USR2_ORE, sport->port.membase + USR2);
+ ret = IRQ_HANDLED;
}
- return IRQ_HANDLED;
+ return ret;
}
/*
--
1.9.1

61
target/linux/imx6/patches-4.4/113-serial-imx-make-sure-unhandled-irqs-are-disabled.patch Normal file
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@ -0,0 +1,61 @@
From a58c6360b9eb3a2374b0b069ba9ce7baec0f26df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>
Date: Thu, 24 Mar 2016 14:24:22 +0100
Subject: [PATCH 3/3] serial: imx: make sure unhandled irqs are disabled
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Make sure that events that are not handled in the irq function don't
trigger an interrupt.
When the serial port is operated in DTE mode, the events for DCD and RI
events are enabled after a system reset by default.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Petr Štetiar <ynezz@true.cz>
---
drivers/tty/serial/imx.c | 23 ++++++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 5ced61e..fcd48fd 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1221,11 +1221,32 @@ static int imx_startup(struct uart_port *port)
temp |= (UCR2_RXEN | UCR2_TXEN);
if (!sport->have_rtscts)
temp |= UCR2_IRTS;
+ /*
+ * make sure the edge sensitive RTS-irq is disabled,
+ * we're using RTSD instead.
+ */
+ if (!is_imx1_uart(sport))
+ temp &= ~UCR2_RTSEN;
writel(temp, sport->port.membase + UCR2);
if (!is_imx1_uart(sport)) {
temp = readl(sport->port.membase + UCR3);
- temp |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
+
+ /*
+ * The effect of RI and DCD differs depending on the UFCR_DCEDTE
+ * bit. In DCE mode they control the outputs, in DTE mode they
+ * enable the respective irqs. At least the DCD irq cannot be
+ * cleared on i.MX25 at least, so it's not usable and must be
+ * disabled. I don't have test hardware to check if RI has the
+ * same problem but I consider this likely so it's disabled for
+ * now, too.
+ */
+ temp |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP |
+ UCR3_RI | UCR3_DCD;
+
+ if (sport->dte_mode)
+ temp &= ~(UCR3_RI | UCR3_DCD);
+
writel(temp, sport->port.membase + UCR3);
}
--
1.9.1