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

[Jonathan Cameron <jic23@kernel.org>]

On 09/08/16 14:59, Lee Jones wrote:
> On Mon, 01 Aug 2016, Enric Balletbo i Serra wrote:
> 
>> 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 +++++++++++++++++++++++++++++++++++
> 
> For the MFD changes:
>   Acked-by: Lee Jones <lee.jones@linaro.org>
Applied.  Will send a note out at the end about an immutable branch.

Jonathan
> 
>>  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 */
>