serial: 8250_dw: Add ACPI 5.0 support

This adds support for ACPI 5.0 enumerated Designware UARTs.
ACPI does not deliver information about uart clk, so
delivering it with the driver_data.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index e104092f7d51365e8d9fc1f49da1ac84af3d9d9d..f6eeff02dceddf8e9de687fb86c0bca8b4e9cb20 100644 (file)
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -2,6 +2,7 @@
  * Synopsys DesignWare 8250 driver.
  *
  * Copyright 2011 Picochip, Jamie Iles.
+ * Copyright 2013 Intel Corporation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -24,12 +25,16 @@
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
+#include <linux/acpi.h>
 
 /* Offsets for the DesignWare specific registers */
 #define DW_UART_USR    0x1f /* UART Status Register */
 #define DW_UART_CPR    0xf4 /* Component Parameter Register */
 #define DW_UART_UCV    0xf8 /* UART Component Version */
 
+/* Intel Low Power Subsystem specific */
+#define LPSS_PRV_CLOCK_PARAMS 0x800
+
 /* Component Parameter Register bits */
 #define DW_UART_CPR_ABP_DATA_WIDTH     (3 << 0)
 #define DW_UART_CPR_AFCE_MODE          (1 << 4)
@@ -138,6 +143,30 @@ static int dw8250_probe_of(struct uart_port *p)
        return 0;
 }
 
+static int dw8250_probe_acpi(struct uart_port *p)
+{
+       const struct acpi_device_id *id;
+       u32 reg;
+
+       id = acpi_match_device(p->dev->driver->acpi_match_table, p->dev);
+       if (!id)
+               return -ENODEV;
+
+       p->iotype = UPIO_MEM32;
+       p->serial_in = dw8250_serial_in32;
+       p->serial_out = dw8250_serial_out32;
+       p->regshift = 2;
+       p->uartclk = (unsigned int)id->driver_data;
+
+       /* Fix Haswell issue where the clocks do not get enabled */
+       if (!strcmp(id->id, "INT33C4") || !strcmp(id->id, "INT33C5")) {
+               reg = readl(p->membase + LPSS_PRV_CLOCK_PARAMS);
+               writel(reg | 1, p->membase + LPSS_PRV_CLOCK_PARAMS);
+       }
+
+       return 0;
+}
+
 static void dw8250_setup_port(struct uart_8250_port *up)
 {
        struct uart_port        *p = &up->port;
@@ -199,6 +228,10 @@ static int dw8250_probe(struct platform_device *pdev)
                err = dw8250_probe_of(&uart.port);
                if (err)
                        return err;
+       } else if (ACPI_HANDLE(&pdev->dev)) {
+               err = dw8250_probe_acpi(&uart.port);
+               if (err)
+                       return err;
        } else {
                return -ENODEV;
        }
@@ -258,11 +291,19 @@ static const struct of_device_id dw8250_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, dw8250_of_match);
 
+static const struct acpi_device_id dw8250_acpi_match[] = {
+       { "INT33C4", 100000000 },
+       { "INT33C5", 100000000 },
+       { },
+};
+MODULE_DEVICE_TABLE(acpi, dw8250_acpi_match);
+
 static struct platform_driver dw8250_platform_driver = {
        .driver = {
                .name           = "dw-apb-uart",
                .owner          = THIS_MODULE,
                .of_match_table = dw8250_of_match,
+               .acpi_match_table = ACPI_PTR(dw8250_acpi_match),
        },
        .probe                  = dw8250_probe,
        .remove                 = dw8250_remove,

diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index d79208f4723783869a5686b999e5560f7d5b4253..3ce3e7533e4ca1e660e2b8c7a214edd76df35f97 100644 (file)
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -256,7 +256,7 @@ config SERIAL_8250_FSL
 
 config SERIAL_8250_DW
        tristate "Support for Synopsys DesignWare 8250 quirks"
-       depends on SERIAL_8250 && OF
+       depends on SERIAL_8250
        help
          Selecting this option will enable handling of the extra features
          present in the Synopsys DesignWare APB UART.