diff options
| author | Andre Przywara <andre.przywara@arm.com> | 2015-05-21 19:26:21 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-05-24 23:08:51 +0300 |
| commit | 71eec4836b834b992e0cefeefc8b85efe4cb185b (patch) | |
| tree | daa964b2f0b2ecaa0cc9ac08e4675cc0cc1f6de5 /drivers | |
| parent | 9c4ef4b0301673c6fa48b5ad138b6ce94e34c841 (diff) | |
| download | linux-71eec4836b834b992e0cefeefc8b85efe4cb185b.tar.xz | |
drivers: PL011: allow avoiding UART enabling/disabling
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>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 7ecf3b380132..3f6b9150e575 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -78,6 +78,7 @@ struct vendor_data { bool oversampling; bool dma_threshold; bool cts_event_workaround; + bool always_enabled; unsigned int (*get_fifosize)(struct amba_device *dev); }; @@ -94,6 +95,7 @@ static struct vendor_data vendor_arm = { .oversampling = false, .dma_threshold = false, .cts_event_workaround = false, + .always_enabled = false, .get_fifosize = get_fifosize_arm, }; @@ -109,6 +111,7 @@ static struct vendor_data vendor_st = { .oversampling = true, .dma_threshold = true, .cts_event_workaround = true, + .always_enabled = false, .get_fifosize = get_fifosize_st, }; @@ -1958,7 +1961,7 @@ 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; @@ -1975,10 +1978,12 @@ 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); @@ -1989,7 +1994,8 @@ 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); |