acpi: Add map for controlling USB port power

Some devices have GPIO pins that control USB port power connected to
the EC, so they cannot be toggled by ACPI. This patch adds a memory
map between the EC and ACPI that can be used on such devices. It can
hold the power state of up to 8 USB ports. Currently, only dumb power
ports are supported.

BUG=chromium:833436
BRANCH=fizz
TEST=On a fizz that runs BIOS with EC_ACPI_MEM_USB_PORT_POWER mapped,
check that both reads and writes are propagated.

Change-Id: I413defcb9e4d234fea7f54d46b6b8a1a10efa31e
Signed-off-by: Emil Lundmark <lndmrk@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1069273
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
(cherry picked from commit aca6cb220c1aab9debf0fd604a6f3502d29122ec)
Reviewed-on: https://chromium-review.googlesource.com/1096936
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>

2 files changed, 64 insertions, 0 deletions

diff --git a/common/acpi.c b/common/acpi.c
index e21eb93b97..5f3ee04fb4 100644
--- a/common/acpi.c
+++ b/common/acpi.c
@@ -8,6 +8,7 @@
 #include "common.h"
 #include "console.h"
 #include "dptf.h"
+#include "gpio.h"
 #include "hooks.h"
 #include "host_command.h"
 #include "lpc.h"
@@ -15,6 +16,7 @@
 #include "tablet_mode.h"
 #include "pwm.h"
 #include "timer.h"
+#include "usb_charge.h"
 #include "util.h"
 
 /* Console output macros */
@@ -36,6 +38,10 @@ static int __bss_slow dptf_temp_sensor_id;	/* last sensor ID written */
 static int __bss_slow dptf_temp_threshold;	/* last threshold written */
 #endif
 
+#ifdef CONFIG_USB_PORT_POWER_DUMB
+extern const int usb_port_enable[USB_PORT_COUNT];
+#endif
+
 /*
  * Keep a read cache of four bytes when burst mode is enabled, which is the
  * size of the largest non-string memmap data type.
@@ -202,6 +208,26 @@ int acpi_ap_to_ec(int is_cmd, uint8_t value, uint8_t *resultptr)
 			result = val >> (8 * off);
 			break;
 			}
+
+#ifdef CONFIG_USB_PORT_POWER_DUMB
+		case EC_ACPI_MEM_USB_PORT_POWER: {
+			int i;
+			const int port_count = MIN(8, USB_PORT_COUNT);
+
+			/*
+			 * Convert each USB port power GPIO signal to a bit
+			 * field with max size 8 bits. USB port ID (index) 0 is
+			 * the least significant bit.
+			 */
+			result = 0;
+			for (i = 0; i < port_count; ++i) {
+				if (gpio_get_level(usb_port_enable[i]) != 0)
+					result |= 1 << i;
+			}
+			break;
+			}
+#endif
+
 		default:
 			result = acpi_read(acpi_addr);
 			break;
@@ -266,6 +292,35 @@ int acpi_ap_to_ec(int is_cmd, uint8_t value, uint8_t *resultptr)
 			}
 			break;
 #endif
+
+#ifdef CONFIG_USB_PORT_POWER_DUMB
+		case EC_ACPI_MEM_USB_PORT_POWER: {
+			int i;
+			int mode_field = data;
+			const int port_count = MIN(8, USB_PORT_COUNT);
+
+			/*
+			 * Read the port power bit field (with max size 8 bits)
+			 * and set the charge mode of each USB port accordingly.
+			 * USB port ID 0 is the least significant bit.
+			 */
+			for (i = 0; i < port_count; ++i) {
+				int mode = USB_CHARGE_MODE_DISABLED;
+
+				if (mode_field & 1)
+					mode = USB_CHARGE_MODE_ENABLED;
+
+				if (usb_charge_set_mode(i, mode)) {
+					CPRINTS("ERROR: could not set charge "
+						"mode of USB port p%d to %d",
+						i, mode);
+				}
+				mode_field >>= 1;
+			}
+			break;
+			}
+#endif
+
 		default:
 			CPRINTS("ACPI write 0x%02x = 0x%02x (ignored)",
 				acpi_addr, data);
diff --git a/include/ec_commands.h b/include/ec_commands.h
index 022a3c82df..ff076e66f0 100644
--- a/include/ec_commands.h
+++ b/include/ec_commands.h
@@ -353,6 +353,15 @@
 #define EC_ACPI_MEM_BATTERY_INDEX    0x12
 
 /*
+ * USB Port Power. Each bit indicates whether the corresponding USB ports' power
+ * is enabled (1) or disabled (0).
+ *   bit 0 USB port ID 0
+ *   ...
+ *   bit 7 USB port ID 7
+ */
+#define EC_ACPI_MEM_USB_PORT_POWER 0x13
+
+/*
  * ACPI addresses 0x20 - 0xff map to EC_MEMMAP offset 0x00 - 0xdf.  This data
  * is read-only from the AP.  Added in EC_ACPI_MEM_VERSION 2.
  */