Hi Shawn, Russell,
I noticed this change is in linux-next and but I happen to hit an issue
with this as I tested it with earlycon enabled today for the first time.
On 08/07/16 10:00, Shawn Guo wrote:
For some reason we do not really understand, ZTE hardware designers
choose to define PL011 Flag Register bit positions differently from
standard ones as below.
Bit Standard ZTE
-----------------------------------
CTS 0 1
DSR 1 3
BUSY 3 8
RI 8 0
Let's define these bits into vendor data and get ZTE PL011 supported
properly.
Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
[...]
@@ -2303,13 +2325,16 @@ static struct console amba_console = {
static void pl011_putc(struct uart_port *port, int c)
{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
cpu_relax();
if (port->iotype == UPIO_MEM32)
writel(c, port->membase + UART01x_DR);
else
writeb(c, port->membase + UART01x_DR);
- while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY)
+ while (readl(port->membase + UART01x_FR) & uap->vendor->fr_busy)
cpu_relax();
}
The above hunk won't work for early console devices. The earlycon_device
just has uart_port and is not uart_amba_port. I don't know how to fix
this properly but I thought we could reuse private_data in uart_port for
early_con devices. Something like below(incomplete for other vendors,
works only for ARM)
Regards,
Sudeep
-->8
diff --git i/drivers/tty/serial/amba-pl011.c
w/drivers/tty/serial/amba-pl011.c
index 0b78b04e895e..abe88223790c 100644
--- i/drivers/tty/serial/amba-pl011.c
+++ w/drivers/tty/serial/amba-pl011.c
@@ -2330,8 +2330,7 @@ static struct console amba_console = {
static void pl011_putc(struct uart_port *port, int c)
{
- struct uart_amba_port *uap =
- container_of(port, struct uart_amba_port, port);
+ struct vendor_data *vendor = port->private_data;
while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
cpu_relax();
@@ -2339,7 +2338,7 @@ static void pl011_putc(struct uart_port *port, int c)
writel(c, port->membase + UART01x_DR);
else
writeb(c, port->membase + UART01x_DR);
- while (readl(port->membase + UART01x_FR) & uap->vendor->fr_busy)
+ while (readl(port->membase + UART01x_FR) & vendor->fr_busy)
cpu_relax();
}
@@ -2356,6 +2355,7 @@ static int __init pl011_early_console_setup(struct
earlycon_device *device,
if (!device->port.membase)
return -ENODEV;
+ device->port.private_data = &vendor_arm;
device->con->write = pl011_early_write;
return 0;
}
--
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