Hi,
On 20/08/2024 10:00, Michal Orzel wrote:
On 20/08/2024 10:22, Amneesh Singh wrote:
Quite a few TI K3 devices do not have clock-frequency specified in their
respective UART nodes. However hard-coding the frequency is not a
solution as the function clock input can differ between SoCs. So, use a
default frequency of 48MHz if the device tree does not specify one.
I'd mention that this is same as Linux
Signed-off-by: Amneesh Singh <a-sing...@ti.com>
---
xen/drivers/char/omap-uart.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
---
v1: https://lore.kernel.org/all/20240719113313.145587-1-a-sing...@ti.com/T/
v1 -> v2
- Ditch adding a dtuart option
- Use a default value instead
This default is the same one as found in the 8250_omap driver of the
linux tree. Already tested with Xen.
diff --git a/xen/drivers/char/omap-uart.c b/xen/drivers/char/omap-uart.c
index 1079198..9d3d39c 100644
--- a/xen/drivers/char/omap-uart.c
+++ b/xen/drivers/char/omap-uart.c
@@ -48,6 +48,9 @@
/* System configuration register */
#define UART_OMAP_SYSC_DEF_CONF 0x0d /* autoidle mode, wakeup is enabled
*/
+/* default clock frequency in hz */
+#define UART_OMAP_DEFAULT_CLK_SPEED 48000000
I think this should have U suffix to please MISRA 7.2
+
#define omap_read(uart, off) readl((uart)->regs + ((off) << REG_SHIFT))
#define omap_write(uart, off, val) writel(val, \
(uart)->regs + ((off) << REG_SHIFT))
@@ -322,8 +325,9 @@ static int __init omap_uart_init(struct dt_device_node *dev,
res = dt_property_read_u32(dev, "clock-frequency", &clkspec);
if ( !res )
{
- printk("omap-uart: Unable to retrieve the clock frequency\n");
- return -EINVAL;
+ printk("omap-uart: Unable to retrieve the clock frequency, "
+ "defaulting to %uHz\n", UART_OMAP_DEFAULT_CLK_SPEED);
Even though there is a comma, printk messages should not really be split. In
such cases it's fine
to exceed 80 chars limit. Or do:
In general, we allow to exceed the limit only for the message. If there
are arguments then ...
printk("omap-uart: Clock frequency not specified, defaulting to
%uHz\n",
UART_OMAP_DEFAULT_CLK_SPEED);
... this is the preferred approach. I can do the update on commit if an
updated commit message is provided.
Cheers,
--
Julien Grall
