@@ -18,6 +18,7 @@
static char *options;
static struct acpi_generic_address address;
+static bool sbsa_32_bit;
static int __init parse_spcr_init(void)
{
@@ -60,6 +61,7 @@ static int __init parse_spcr_init(void)
}
address = table->serial_port;
+ sbsa_32_bit = table->interface_type == ACPI_DBG2_ARM_SBSA_32BIT;
done:
early_acpi_os_unmap_memory((void __iomem *)table, table_size);
@@ -114,3 +116,23 @@ bool acpi_console_check(struct uart_port *uport)
return false;
}
+
+/**
+ * acpi_console_sbsa_32bit - Tell if SPCR specifies 32-bit SBSA.
+ *
+ * Some implementations of ARM SBSA serial port hardware require that access
+ * to the registers should be 32-bit. Unfortunately, the only way for
+ * the driver to tell if it's the case is to use the data from ACPI SPCR/DBG2
+ * tables. In this case the value of the 'Interface Type' field of the SPCR
+ * table is ACPI_DBG2_ARM_SBSA_32BIT.
+ *
+ * Return: true if access should be 32-bit wide.
+ */
+bool acpi_console_sbsa_32bit(void)
+{
+ if (acpi_disabled || parse_spcr() < 0)
+ return false;
+
+ return sbsa_32_bit;
+}
+EXPORT_SYMBOL(acpi_console_sbsa_32bit);
@@ -2541,6 +2541,8 @@ static int sbsa_uart_probe(struct platform_device *pdev)
baudrate = 115200;
}
+ vendor_sbsa.access_32b = acpi_console_sbsa_32bit();
+
portnr = pl011_find_free_port();
if (portnr < 0)
return portnr;
@@ -1007,11 +1007,16 @@ static inline struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
struct uart_port;
#ifdef CONFIG_ACPI_SPCR_TABLE
bool acpi_console_check(struct uart_port *uport);
+bool acpi_console_sbsa_32bit(void);
#else
static inline bool acpi_console_check(struct uart_port *uport)
{
return FALSE;
}
+static inline bool acpi_console_sbsa_32bit(void)
+{
+ return false;
+}
#endif
#endif /*_LINUX_ACPI_H*/
Some implementations of ARM SBSA serial port hardware require that access to the registers should be 32-bit. Unfortunately, the only way for the driver to tell if it's the case is to use the data from ACPI SPCR/DBG2 tables. In this case the value of the 'Interface Type' field of the SPCR table is ACPI_DBG2_ARM_SBSA_32BIT. How this value is described in the DBG2 spec: "(deprecated) ARM SBSA (2.x only) Generic UART supporting only 32-bit accesses" Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org> --- drivers/acpi/spcr.c | 22 ++++++++++++++++++++++ drivers/tty/serial/amba-pl011.c | 2 ++ include/linux/acpi.h | 5 +++++ 3 files changed, 29 insertions(+) -- 2.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html