[PATCH v4 19/21] arm/acpi: Initialize serial port from ACPI SPCR table

[Shannon Zhao <zhaoshenglong@huawei.com>]

From: Shannon Zhao <shannon.zhao@linaro.org>

Parse ACPI SPCR (Serial Port Console Redirection table) table and
initialize the serial port pl011.

Signed-off-by: Parth Dixit <parth.dixit@linaro.org>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
---
V4: Add other fields of SPCR Interface type
---
 xen/drivers/char/pl011.c  | 37 +++++++++++++++++++++++++++++++++++++
 xen/include/acpi/actbl2.h |  9 +++++++++
 2 files changed, 46 insertions(+)

diff --git a/xen/drivers/char/pl011.c b/xen/drivers/char/pl011.c
index 7e16294..9d47299 100644
--- a/xen/drivers/char/pl011.c
+++ b/xen/drivers/char/pl011.c
@@ -27,6 +27,7 @@
 #include <asm/device.h>
 #include <xen/mm.h>
 #include <xen/vmap.h>
+#include <xen/acpi.h>
 #include <asm/pl011-uart.h>
 #include <asm/io.h>
 
@@ -308,6 +309,42 @@ DT_DEVICE_START(pl011, "PL011 UART", DEVICE_SERIAL)
         .init = pl011_dt_uart_init,
 DT_DEVICE_END
 
+#ifdef CONFIG_ACPI
+static int __init pl011_acpi_uart_init(const void *data)
+{
+    acpi_status status;
+    struct acpi_table_spcr *spcr = NULL;
+    int res;
+
+    status = acpi_get_table(ACPI_SIG_SPCR, 0,
+                            (struct acpi_table_header **)&spcr);
+
+    if ( ACPI_FAILURE(status) )
+    {
+        printk("pl011: Failed to get SPCR table\n");
+        return -EINVAL;
+    }
+
+    /* trigger/polarity information is not available in spcr */
+    irq_set_type(spcr->interrupt, IRQ_TYPE_EDGE_BOTH);
+
+    res = pl011_uart_init(spcr->interrupt, spcr->serial_port.address,
+                          PAGE_SIZE);
+    if ( res < 0 )
+    {
+        printk("pl011: Unable to initialize\n");
+        return res;
+    }
+
+    return 0;
+}
+
+ACPI_DEVICE_START(apl011, "PL011 UART", DEVICE_SERIAL)
+        .class_type = ACPI_SPCR_TYPE_PL011,
+        .init = pl011_acpi_uart_init,
+ACPI_DEVICE_END
+#endif
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/acpi/actbl2.h b/xen/include/acpi/actbl2.h
index 87bc6b3..d0508be 100644
--- a/xen/include/acpi/actbl2.h
+++ b/xen/include/acpi/actbl2.h
@@ -815,6 +815,15 @@ struct acpi_table_spcr {
 
 #define ACPI_SPCR_DO_NOT_DISABLE    (1)
 
+/* SPCR Interface type */
+#define ACPI_SPCR_TYPE_16550		0
+#define ACPI_SPCR_TYPE_16550_SUB	0x1
+#define ACPI_SPCR_TYPE_PL011		0x3
+#define ACPI_SPCR_TYPE_SBSA_32		0xd
+#define ACPI_SPCR_TYPE_SBSA		0xe
+#define ACPI_SPCR_TYPE_DCC		0xf
+#define ACPI_SPCR_TYPE_BCM2835		0x10
+
 /*******************************************************************************
  *
  * SPMI - Server Platform Management Interface table
-- 
2.0.4