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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2017-05-24 21:38:46 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-05-09 09:50:19 +0200
commitaa6b517e74512ef8373ff66a40f4925f9b6edab6 (patch)
treed80d8c47cc9ad73fd15d6f690c1d22488f3ad9d1 /drivers
parent23fb8f797e6bee5c39b43e6f4c6f15203ee8ea14 (diff)
serial: imx: ensure UCR3 and UFCR are setup correctly
commit 6df765dca378bddf994cfd2044acafa501bd800f upstream. Commit e61c38d85b73 ("serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off") has a flaw: While UCR3 and UFCR were modified using read-modify-write before it switched to write register values independent of the previous state. That's a good idea in principle (and that's why I did it) but needs more care. This patch reinstates read-modify-write for UFCR and for UCR3 ensures that RXDMUXSEL and ADNIMP are set for post imx1. Fixes: e61c38d85b73 ("serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Mika Penttilä <mika.penttila@nextfour.com> Tested-by: Mika Penttilä <mika.penttila@nextfour.com> Acked-by: Steve Twiss <stwiss.opensource@diasemi.com> Tested-by: Steve Twiss <stwiss.opensource@diasemi.com> Cc: Chris Ruehl <chris.ruehl@gtsys.com.hk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/tty/serial/imx.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index f575a33974fa..ecadc27eea48 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -2145,7 +2145,9 @@ static int serial_imx_probe(struct platform_device *pdev)
* and DCD (when they are outputs) or enables the respective
* irqs. So set this bit early, i.e. before requesting irqs.
*/
- writel(UFCR_DCEDTE, sport->port.membase + UFCR);
+ reg = readl(sport->port.membase + UFCR);
+ if (!(reg & UFCR_DCEDTE))
+ writel(reg | UFCR_DCEDTE, sport->port.membase + UFCR);
/*
* Disable UCR3_RI and UCR3_DCD irqs. They are also not
@@ -2156,7 +2158,15 @@ static int serial_imx_probe(struct platform_device *pdev)
sport->port.membase + UCR3);
} else {
- writel(0, sport->port.membase + UFCR);
+ unsigned long ucr3 = UCR3_DSR;
+
+ reg = readl(sport->port.membase + UFCR);
+ if (reg & UFCR_DCEDTE)
+ writel(reg & ~UFCR_DCEDTE, sport->port.membase + UFCR);
+
+ if (!is_imx1_uart(sport))
+ ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
+ writel(ucr3, sport->port.membase + UCR3);
}
clk_disable_unprepare(sport->clk_ipg);