x86/geode/alix2: Supplement driver to include GPIO button support

GPIO 24 is used in reference designs as a soft-reset button, and
the alix2 is no exception.  Add it as a gpio-button.

Use symbolic values to describe BIOS addresses.

Record the model number.

Signed-off-by: Philip A. Prindeville <philipp@redfish-solutions.com>
Acked-by: Ed Wildgoose <kernel@wildgooses.com>
Acked-by: Andres Salomon <dilinger@queued.net>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-sjp6k1rjksitx1pej0c0qxd1@git.kernel.org
[ tidied up the code a bit ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 67 insertions, 9 deletions

diff --git a/arch/x86/platform/geode/alix.c b/arch/x86/platform/geode/alix.c
index dc5f1d32ace..90e23e7679a 100644
--- a/arch/x86/platform/geode/alix.c
+++ b/arch/x86/platform/geode/alix.c
@@ -6,6 +6,7 @@
  *
  * Copyright (C) 2008 Constantin Baranov <const@mimas.ru>
  * Copyright (C) 2011 Ed Wildgoose <kernel@wildgooses.com>
+ *                and Philip Prindeville <philipp@redfish-solutions.com>
  *
  * TODO: There are large similarities with leds-net5501.c
  * by Alessandro Zummo <a.zummo@towertech.it>
@@ -24,14 +25,47 @@
 #include <linux/leds.h>
 #include <linux/platform_device.h>
 #include <linux/gpio.h>
+#include <linux/input.h>
+#include <linux/gpio_keys.h>
+#include <linux/dmi.h>
 
 #include <asm/geode.h>
 
+#define BIOS_SIGNATURE_TINYBIOS         0xf0000
+#define BIOS_SIGNATURE_COREBOOT         0x500
+#define BIOS_REGION_SIZE                0x10000
+
 static bool force = 0;
 module_param(force, bool, 0444);
 /* FIXME: Award bios is not automatically detected as Alix platform */
 MODULE_PARM_DESC(force, "Force detection as ALIX.2/ALIX.3 platform");
 
+static struct gpio_keys_button alix_gpio_buttons[] = {
+        {
+                .code                   = KEY_RESTART,
+                .gpio                   = 24,
+                .active_low             = 1,
+                .desc                   = "Reset button",
+                .type                   = EV_KEY,
+                .wakeup                 = 0,
+                .debounce_interval      = 100,
+                .can_disable            = 0,
+        }
+};
+static struct gpio_keys_platform_data alix_buttons_data = {
+        .buttons                        = alix_gpio_buttons,
+        .nbuttons                       = ARRAY_SIZE(alix_gpio_buttons),
+        .poll_interval                  = 20,
+};
+
+static struct platform_device alix_buttons_dev = {
+        .name                           = "gpio-keys-polled",
+        .id                             = 1,
+        .dev = {
+                .platform_data          = &alix_buttons_data,
+        }
+};
+
 static struct gpio_led alix_leds[] = {
         {
                 .name = "alix:1",
@@ -64,17 +98,22 @@ static struct platform_device alix_leds_dev = {
         .dev.platform_data = &alix_leds_data,
 };
 
+static struct __initdata platform_device *alix_devs[] = {
+        &alix_buttons_dev,
+        &alix_leds_dev,
+};
+
 static void __init register_alix(void)
 {
         /* Setup LED control through leds-gpio driver */
-        platform_device_register(&alix_leds_dev);
+        platform_add_devices(alix_devs, ARRAY_SIZE(alix_devs));
 }
 
-static int __init alix_present(unsigned long bios_phys,
+static bool __init alix_present(unsigned long bios_phys,
                                 const char *alix_sig,
                                 size_t alix_sig_len)
 {
-        const size_t bios_len = 0x00010000;
+        const size_t bios_len = BIOS_REGION_SIZE;
         const char *bios_virt;
         const char *scan_end;
         const char *p;
@@ -84,7 +123,7 @@ static int __init alix_present(unsigned long bios_phys,
                 printk(KERN_NOTICE "%s: forced to skip BIOS test, "
                        "assume system is ALIX.2/ALIX.3\n",
                        KBUILD_MODNAME);
-                return 1;
+                return true;
         }
 
         bios_virt = phys_to_virt(bios_phys);
@@ -109,15 +148,33 @@ static int __init alix_present(unsigned long bios_phys,
                         *a = '\0';
 
                 tail = p + alix_sig_len;
-                if ((tail[0] == '2' || tail[0] == '3')) {
+                if ((tail[0] == '2' || tail[0] == '3' || tail[0] == '6')) {
                         printk(KERN_INFO
                                "%s: system is recognized as \"%s\"\n",
                                KBUILD_MODNAME, name);
-                        return 1;
+                        return true;
                 }
         }
 
-        return 0;
+        return false;
+}
+
+static bool __init alix_present_dmi(void)
+{
+        const char *vendor, *product;
+
+        vendor = dmi_get_system_info(DMI_SYS_VENDOR);
+        if (!vendor || strcmp(vendor, "PC Engines"))
+                return false;
+
+        product = dmi_get_system_info(DMI_PRODUCT_NAME);
+        if (!product || (strcmp(product, "ALIX.2D") && strcmp(product, "ALIX.6")))
+                return false;
+
+        printk(KERN_INFO "%s: system is recognized as \"%s %s\"\n",
+               KBUILD_MODNAME, vendor, product);
+
+        return true;
 }
 
 static int __init alix_init(void)
@@ -128,8 +185,9 @@ static int __init alix_init(void)
         if (!is_geode())
                 return 0;
 
-        if (alix_present(0xf0000, tinybios_sig, sizeof(tinybios_sig) - 1) ||
-            alix_present(0x500, coreboot_sig, sizeof(coreboot_sig) - 1))
+        if (alix_present(BIOS_SIGNATURE_TINYBIOS, tinybios_sig, sizeof(tinybios_sig) - 1) ||
+            alix_present(BIOS_SIGNATURE_COREBOOT, coreboot_sig, sizeof(coreboot_sig) - 1) ||
+            alix_present_dmi())
                 register_alix();
 
         return 0;