toshiba_acpi: Add System Configuration Interface

SCI stands for System Configuration Interface,
which aim is to conceal differences in hardware
between different models.

This patch introduces four new calls: sci_open,
sci_close, sci_read and sci_write, along with
its definitions and return codes which will be
used by later patches.

More information about the SCI can be found at
Jonathan Buzzard's website [1].

[1] http://www.buzzard.me.uk/toshiba/docs.html

Signed-off-by: Azael Avalos <coproscefalo@gmail.com>
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

1 files changed, 79 insertions, 0 deletions

diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c
index 90dd7645a9e5..c4680037bbfd 100644
--- a/drivers/platform/x86/toshiba_acpi.c
+++ b/drivers/platform/x86/toshiba_acpi.c
@@ -77,6 +77,9 @@ MODULE_LICENSE("GPL");
  * However the ACPI methods seem to be incomplete in some areas (for
  * example they allow setting, but not reading, the LCD brightness value),
  * so this is still useful.
+ * 
+ * SCI stands for "System Configuration Interface" which aim is to
+ * conceal differences in hardware between different models.
  */
 
 #define HCI_WORDS                       6
@@ -84,12 +87,20 @@ MODULE_LICENSE("GPL");
 /* operations */
 #define HCI_SET                         0xff00
 #define HCI_GET                         0xfe00
+#define SCI_OPEN                        0xf100
+#define SCI_CLOSE                       0xf200
+#define SCI_GET                         0xf300
+#define SCI_SET                         0xf400
 
 /* return codes */
 #define HCI_SUCCESS                     0x0000
 #define HCI_FAILURE                     0x1000
 #define HCI_NOT_SUPPORTED               0x8000
 #define HCI_EMPTY                       0x8c00
+#define SCI_OPEN_CLOSE_OK               0x0044
+#define SCI_ALREADY_OPEN                0x8100
+#define SCI_NOT_OPENED                  0x8200
+#define SCI_NOT_PRESENT                 0x8600
 
 /* registers */
 #define HCI_FAN                         0x0004
@@ -280,6 +291,74 @@ static acpi_status hci_read2(struct toshiba_acpi_dev *dev, u32 reg,
         return status;
 }
 
+/* common sci tasks
+ */
+
+static int sci_open(struct toshiba_acpi_dev *dev)
+{
+        u32 in[HCI_WORDS] = { SCI_OPEN, 0, 0, 0, 0, 0 };
+        u32 out[HCI_WORDS];
+        acpi_status status;
+
+        status = hci_raw(dev, in, out);
+        if  (ACPI_FAILURE(status) || out[0] == HCI_FAILURE) {
+                pr_err("ACPI call to open SCI failed\n");
+                return 0;
+        }
+
+        if (out[0] == SCI_OPEN_CLOSE_OK) {
+                return 1;
+        } else if (out[0] == SCI_ALREADY_OPEN) {
+                pr_info("Toshiba SCI already opened\n");
+                return 1;
+        } else if (out[0] == SCI_NOT_PRESENT) {
+                pr_info("Toshiba SCI is not present\n");
+        }
+
+        return 0;
+}
+
+static void sci_close(struct toshiba_acpi_dev *dev)
+{
+        u32 in[HCI_WORDS] = { SCI_CLOSE, 0, 0, 0, 0, 0 };
+        u32 out[HCI_WORDS];
+        acpi_status status;
+
+        status = hci_raw(dev, in, out);
+        if (ACPI_FAILURE(status) || out[0] == HCI_FAILURE) {
+                pr_err("ACPI call to close SCI failed\n");
+                return;
+        }
+
+        if (out[0] == SCI_OPEN_CLOSE_OK)
+                return;
+        else if (out[0] == SCI_NOT_OPENED)
+                pr_info("Toshiba SCI not opened\n");
+        else if (out[0] == SCI_NOT_PRESENT)
+                pr_info("Toshiba SCI is not present\n");
+}
+
+static acpi_status sci_read(struct toshiba_acpi_dev *dev, u32 reg,
+                            u32 *out1, u32 *result)
+{
+        u32 in[HCI_WORDS] = { SCI_GET, reg, 0, 0, 0, 0 };
+        u32 out[HCI_WORDS];
+        acpi_status status = hci_raw(dev, in, out);
+        *out1 = out[2];
+        *result = (ACPI_SUCCESS(status)) ? out[0] : HCI_FAILURE;
+        return status;
+}
+
+static acpi_status sci_write(struct toshiba_acpi_dev *dev, u32 reg,
+                             u32 in1, u32 *result)
+{
+        u32 in[HCI_WORDS] = { SCI_SET, reg, in1, 0, 0, 0 };
+        u32 out[HCI_WORDS];
+        acpi_status status = hci_raw(dev, in, out);
+        *result = (ACPI_SUCCESS(status)) ? out[0] : HCI_FAILURE;
+        return status;
+}
+
 /* Illumination support */
 static int toshiba_illumination_available(struct toshiba_acpi_dev *dev)
 {