From: andre.przywara@arm.com (Andre Przywara)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 08/10] drivers: PL011: allow avoiding UART enabling/disabling
Date: Wed, 4 Mar 2015 17:59:52 +0000 [thread overview]
Message-ID: <1425491994-23913-9-git-send-email-andre.przywara@arm.com> (raw)
In-Reply-To: <1425491994-23913-1-git-send-email-andre.przywara@arm.com>
The SBSA UART should not be enabled or disabled (it is always on),
and consequently the spec lacks the UART_CR register.
Add a vendor specific property to skip disabling or enabling of the
UART. This will be used later by the SBSA UART support.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
drivers/tty/serial/amba-pl011.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index bca5a3f..fdb9fa5 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -79,6 +79,7 @@ struct vendor_data {
bool oversampling;
bool dma_threshold;
bool cts_event_workaround;
+ bool always_enabled;
unsigned int (*get_fifosize)(struct amba_device *dev);
};
@@ -95,6 +96,7 @@ static struct vendor_data vendor_arm = {
.oversampling = false,
.dma_threshold = false,
.cts_event_workaround = false,
+ .always_enabled = false,
.get_fifosize = get_fifosize_arm,
};
@@ -110,6 +112,7 @@ static struct vendor_data vendor_st = {
.oversampling = true,
.dma_threshold = true,
.cts_event_workaround = true,
+ .always_enabled = false,
.get_fifosize = get_fifosize_st,
};
@@ -2059,7 +2062,7 @@ static void
pl011_console_write(struct console *co, const char *s, unsigned int count)
{
struct uart_amba_port *uap = amba_ports[co->index];
- unsigned int status, old_cr, new_cr;
+ unsigned int status, old_cr = 0, new_cr;
unsigned long flags;
int locked = 1;
@@ -2076,10 +2079,12 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
/*
* First save the CR then disable the interrupts
*/
- old_cr = readw(uap->port.membase + UART011_CR);
- new_cr = old_cr & ~UART011_CR_CTSEN;
- new_cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
- writew(new_cr, uap->port.membase + UART011_CR);
+ if (!uap->vendor->always_enabled) {
+ old_cr = readw(uap->port.membase + UART011_CR);
+ new_cr = old_cr & ~UART011_CR_CTSEN;
+ new_cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
+ writew(new_cr, uap->port.membase + UART011_CR);
+ }
uart_console_write(&uap->port, s, count, pl011_console_putchar);
@@ -2090,7 +2095,8 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
do {
status = readw(uap->port.membase + UART01x_FR);
} while (status & UART01x_FR_BUSY);
- writew(old_cr, uap->port.membase + UART011_CR);
+ if (!uap->vendor->always_enabled)
+ writew(old_cr, uap->port.membase + UART011_CR);
if (locked)
spin_unlock(&uap->port.lock);
--
1.7.9.5
next prev parent reply other threads:[~2015-03-04 17:59 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-04 17:59 [PATCH v2 00/10] drivers: PL011: add ARM SBSA Generic UART support Andre Przywara
2015-03-04 17:59 ` [PATCH v2 01/10] drivers: PL011: avoid potential unregister_driver call Andre Przywara
2015-03-12 10:42 ` Russell King - ARM Linux
2015-04-08 15:39 ` Andre Przywara
2015-04-08 18:14 ` Russell King - ARM Linux
2015-03-04 17:59 ` [PATCH v2 02/10] drivers: PL011: refactor pl011_startup() Andre Przywara
2015-03-04 17:59 ` [PATCH v2 03/10] drivers: PL011: refactor pl011_shutdown() Andre Przywara
2015-03-04 17:59 ` [PATCH v2 04/10] drivers: PL011: refactor pl011_set_termios() Andre Przywara
2015-03-04 17:59 ` [PATCH v2 05/10] drivers: PL011: refactor pl011_probe() Andre Przywara
2015-03-04 17:59 ` [PATCH v2 06/10] drivers: PL011: replace UART_MIS reading with _RIS & _IMSC Andre Przywara
2015-03-12 10:46 ` Russell King - ARM Linux
2015-03-04 17:59 ` [PATCH v2 07/10] drivers: PL011: move cts_event workaround into separate function Andre Przywara
2015-03-07 3:00 ` Greg KH
2015-03-04 17:59 ` Andre Przywara [this message]
2015-03-04 17:59 ` [PATCH v2 09/10] drivers: PL011: allow to supply fixed option string Andre Przywara
2015-03-04 17:59 ` [PATCH v2 10/10] drivers: PL011: add support for the ARM SBSA generic UART Andre Przywara
2015-03-09 15:59 ` Dave Martin
2015-03-12 10:52 ` Russell King - ARM Linux
2015-03-12 13:43 ` Andre Przywara
2015-03-12 13:49 ` Russell King - ARM Linux
2015-03-12 13:58 ` Andre Przywara
2015-03-07 3:01 ` [PATCH v2 00/10] drivers: PL011: add ARM SBSA Generic UART support Greg KH
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