[PATCH 4/4] xen/arm: pl011: Add SBSA UART device-tree support

[Michal Orzel <michal.orzel@xxxxxxx>]

We already have all the bits necessary in PL011 driver to support SBSA
UART thanks to commit 032ea8c736d10f02672863c6e369338f948f7ed8 that
enabled it for ACPI. Plumb in the remaining part for device-tree boot:
 - add arm,sbsa-uart compatible to pl011_dt_match (no need for a separate
   struct and DT_DEVICE_START as SBSA is a subset of PL011),
 - from pl011_dt_uart_init(), check for SBSA UART compatible to determine
   the UART type in use.

Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>
---
After this series the last thing not to be in spec for newer UARTs (well,
for rev1.5 introduced in 2007 I believe) is incorrect FIFO size. We hardcode it
to 16 but in r1.5 it is 32. This requires checking the peripheral ID register
or using arm,primecell-periphid dt property for overriding HW. Something to
be done in the future (at least 16 is not harmful).
---
 xen/drivers/char/pl011.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/xen/drivers/char/pl011.c b/xen/drivers/char/pl011.c
index 403b1ac06551..f7bf3ad117af 100644
--- a/xen/drivers/char/pl011.c
+++ b/xen/drivers/char/pl011.c
@@ -286,7 +286,7 @@ static int __init pl011_dt_uart_init(struct dt_device_node 
*dev,
     int res;
     paddr_t addr, size;
     uint32_t io_width;
-    bool mmio32 = false;
+    bool mmio32 = false, sbsa;
 
     if ( strcmp(config, "") )
     {
@@ -320,7 +320,9 @@ static int __init pl011_dt_uart_init(struct dt_device_node 
*dev,
         }
     }
 
-    res = pl011_uart_init(res, addr, size, false, mmio32);
+    sbsa = dt_device_is_compatible(dev, "arm,sbsa-uart");
+
+    res = pl011_uart_init(res, addr, size, sbsa, mmio32);
     if ( res < 0 )
     {
         printk("pl011: Unable to initialize\n");
@@ -335,6 +337,8 @@ static int __init pl011_dt_uart_init(struct dt_device_node 
*dev,
 static const struct dt_device_match pl011_dt_match[] __initconst =
 {
     DT_MATCH_COMPATIBLE("arm,pl011"),
+    /* No need for a separate struct as SBSA UART is a subset of PL011 */
+    DT_MATCH_COMPATIBLE("arm,sbsa-uart"),
     { /* sentinel */ },
 };
 
-- 
2.25.1