[PATCH v4 3/4] platform/chrome: Introduce a new function to check EC features.

Enric Balletbo i Serra
2016-08-01T09:56:00Z

From: Vincent Palatin <vpalatin@chromium.org>

Use the EC_CMD_GET_FEATURES message to check the supported features for
each MCU.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
[tomeu: adapted to changes in mainline]
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
[enric: remove references to USB PD feature and do it more generic]
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
---

Changes since v3:
- Add Reviewed-by tag.

drivers/platform/chrome/cros_ec_dev.c | 37 +++++++++++++++
include/linux/mfd/cros_ec.h | 1 +
include/linux/mfd/cros_ec_commands.h | 84 +++++++++++++++++++++++++++++++++++
3 files changed, 122 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
index 8abd80d..7eb5307 100644
--- a/drivers/platform/chrome/cros_ec_dev.c
+++ b/drivers/platform/chrome/cros_ec_dev.c
@@ -87,6 +87,41 @@ exit:
return ret;
}

+static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
+{
+ struct cros_ec_command *msg;
+ int ret;
+
+ if (ec->features[0] == -1U && ec->features[1] == -1U) {
+ /* features bitmap not read yet */
+
+ msg = kmalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ msg->version = 0;
+ msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
+ msg->insize = sizeof(ec->features);
+ msg->outsize = 0;
+
+ ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
+ if (ret < 0 || msg->result != EC_RES_SUCCESS) {
+ dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
+ ret, msg->result);
+ memset(ec->features, 0, sizeof(ec->features));
+ }
+
+ memcpy(ec->features, msg->data, sizeof(ec->features));
+
+ dev_dbg(ec->dev, "EC features %08x %08x\n",
+ ec->features[0], ec->features[1]);
+
+ kfree(msg);
+ }
+
+ return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
+}
+
/* Device file ops */
static int ec_device_open(struct inode *inode, struct file *filp)
{
@@ -245,6 +280,8 @@ static int ec_device_probe(struct platform_device *pdev)
ec->ec_dev = dev_get_drvdata(dev->parent);
ec->dev = dev;
ec->cmd_offset = ec_platform->cmd_offset;
+ ec->features[0] = -1U; /* Not cached yet */
+ ec->features[1] = -1U; /* Not cached yet */
device_initialize(&ec->class_dev);
cdev_init(&ec->cdev, &fops);

diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 7769ea6..7f039b2 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -187,6 +187,7 @@ struct cros_ec_dev {
struct cros_ec_device *ec_dev;
struct device *dev;
u16 cmd_offset;
+ u32 features[2];
};

/**
diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
index 8826e0f..1683003 100644
--- a/include/linux/mfd/cros_ec_commands.h
+++ b/include/linux/mfd/cros_ec_commands.h
@@ -713,6 +713,90 @@ struct ec_response_get_set_value {
/* More than one command can use these structs to get/set paramters. */
#define EC_CMD_GSV_PAUSE_IN_S5 0x0c

+/*****************************************************************************/
+/* List the features supported by the firmware */
+#define EC_CMD_GET_FEATURES 0x0d
+
+/* Supported features */
+enum ec_feature_code {
+ /*
+ * This image contains a limited set of features. Another image
+ * in RW partition may support more features.
+ */
+ EC_FEATURE_LIMITED = 0,
+ /*
+ * Commands for probing/reading/writing/erasing the flash in the
+ * EC are present.
+ */
+ EC_FEATURE_FLASH = 1,
+ /*
+ * Can control the fan speed directly.
+ */
+ EC_FEATURE_PWM_FAN = 2,
+ /*
+ * Can control the intensity of the keyboard backlight.
+ */
+ EC_FEATURE_PWM_KEYB = 3,
+ /*
+ * Support Google lightbar, introduced on Pixel.
+ */
+ EC_FEATURE_LIGHTBAR = 4,
+ /* Control of LEDs */
+ EC_FEATURE_LED = 5,
+ /* Exposes an interface to control gyro and sensors.
+ * The host goes through the EC to access these sensors.
+ * In addition, the EC may provide composite sensors, like lid angle.
+ */
+ EC_FEATURE_MOTION_SENSE = 6,
+ /* The keyboard is controlled by the EC */
+ EC_FEATURE_KEYB = 7,
+ /* The AP can use part of the EC flash as persistent storage. */
+ EC_FEATURE_PSTORE = 8,
+ /* The EC monitors BIOS port 80h, and can return POST codes. */
+ EC_FEATURE_PORT80 = 9,
+ /*
+ * Thermal management: include TMP specific commands.
+ * Higher level than direct fan control.
+ */
+ EC_FEATURE_THERMAL = 10,
+ /* Can switch the screen backlight on/off */
+ EC_FEATURE_BKLIGHT_SWITCH = 11,
+ /* Can switch the wifi module on/off */
+ EC_FEATURE_WIFI_SWITCH = 12,
+ /* Monitor host events, through for example SMI or SCI */
+ EC_FEATURE_HOST_EVENTS = 13,
+ /* The EC exposes GPIO commands to control/monitor connected devices. */
+ EC_FEATURE_GPIO = 14,
+ /* The EC can send i2c messages to downstream devices. */
+ EC_FEATURE_I2C = 15,
+ /* Command to control charger are included */
+ EC_FEATURE_CHARGER = 16,
+ /* Simple battery support. */
+ EC_FEATURE_BATTERY = 17,
+ /*
+ * Support Smart battery protocol
+ * (Common Smart Battery System Interface Specification)
+ */
+ EC_FEATURE_SMART_BATTERY = 18,
+ /* EC can dectect when the host hangs. */
+ EC_FEATURE_HANG_DETECT = 19,
+ /* Report power information, for pit only */
+ EC_FEATURE_PMU = 20,
+ /* Another Cros EC device is present downstream of this one */
+ EC_FEATURE_SUB_MCU = 21,
+ /* Support USB Power delivery (PD) commands */
+ EC_FEATURE_USB_PD = 22,
+ /* Control USB multiplexer, for audio through USB port for instance. */
+ EC_FEATURE_USB_MUX = 23,
+ /* Motion Sensor code has an internal software FIFO */
+ EC_FEATURE_MOTION_SENSE_FIFO = 24,
+};
+
+#define EC_FEATURE_MASK_0(event_code) (1UL << (event_code % 32))
+#define EC_FEATURE_MASK_1(event_code) (1UL << (event_code - 32))
+struct ec_response_get_features {
+ uint32_t flags[2];
+} __packed;

/*****************************************************************************/
/* Flash commands */
--
2.1.0