[PATCH 1/4] platform/chrome: cros_ec_lightbar - Add lightbar program feature to sysfs

Enric Balletbo i Serra
2016-10-28T16:56:08Z

Add a program feature so we can upload and run programs for lightbar
sequences. We should be able to use this to shift sequences out of the
EC and save space there.

$ cat <suitable program bin> > /sys/devices/.../cros_ec/program
$ echo program > /sys/devices/.../cros_ec/sequence

Signed-off-by: Eric Caruso <ejcaruso@chromium.org>
Signed-off-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
---
drivers/platform/chrome/cros_ec_lightbar.c | 69 +++++++++++++++++++++++++++++-
include/linux/mfd/cros_ec_commands.h | 12 +++++-
2 files changed, 79 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c
index 8df3d44..2667505 100644
--- a/drivers/platform/chrome/cros_ec_lightbar.c
+++ b/drivers/platform/chrome/cros_ec_lightbar.c
@@ -295,7 +295,8 @@ static ssize_t led_rgb_store(struct device *dev, struct device_attribute *attr,

static char const *seqname[] = {
"ERROR", "S5", "S3", "S0", "S5S3", "S3S0",
- "S0S3", "S3S5", "STOP", "RUN", "PULSE", "TEST", "KONAMI",
+ "S0S3", "S3S5", "STOP", "RUN", "KONAMI",
+ "TAP", "PROGRAM",
};

static ssize_t sequence_show(struct device *dev,
@@ -390,6 +391,69 @@ static ssize_t sequence_store(struct device *dev, struct device_attribute *attr,
return ret;
}

+static ssize_t program_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int extra_bytes, max_size, ret;
+ struct ec_params_lightbar *param;
+ struct cros_ec_command *msg;
+ struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev,
+ class_dev);
+
+ /*
+ * We might need to reject the program for size reasons. The EC
+ * enforces a maximum program size, but we also don't want to try
+ * and send a program that is too big for the protocol. In order
+ * to ensure the latter, we also need to ensure we have extra bytes
+ * to represent the rest of the packet.
+ */
+ extra_bytes = sizeof(*param) - sizeof(param->set_program.data);
+ max_size = min(EC_LB_PROG_LEN, ec->ec_dev->max_request - extra_bytes);
+ if (count > max_size) {
+ dev_err(dev, "Program is %u bytes, too long to send (max: %u)",
+ (unsigned int)count, max_size);
+
+ return -EINVAL;
+ }
+
+ msg = alloc_lightbar_cmd_msg(ec);
+ if (!msg)
+ return -ENOMEM;
+
+ ret = lb_throttle();
+ if (ret)
+ goto exit;
+
+ dev_info(dev, "Copying %zu byte program to EC", count);
+
+ param = (struct ec_params_lightbar *)msg->data;
+ param->cmd = LIGHTBAR_CMD_SET_PROGRAM;
+
+ param->set_program.size = count;
+ memcpy(param->set_program.data, buf, count);
+
+ /*
+ * We need to set the message size manually or else it will use
+ * EC_LB_PROG_LEN. This might be too long, and the program
+ * is unlikely to use all of the space.
+ */
+ msg->outsize = count + extra_bytes;
+
+ ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
+ if (ret < 0)
+ goto exit;
+ if (msg->result != EC_RES_SUCCESS) {
+ ret = -EINVAL;
+ goto exit;
+ }
+
+ ret = count;
+exit:
+ kfree(msg);
+
+ return ret;
+}
+
/* Module initialization */

static DEVICE_ATTR_RW(interval_msec);
@@ -397,12 +461,15 @@ static DEVICE_ATTR_RO(version);
static DEVICE_ATTR_WO(brightness);
static DEVICE_ATTR_WO(led_rgb);
static DEVICE_ATTR_RW(sequence);
+static DEVICE_ATTR_WO(program);
+
static struct attribute *__lb_cmds_attrs[] = {
&dev_attr_interval_msec.attr,
&dev_attr_version.attr,
&dev_attr_brightness.attr,
&dev_attr_led_rgb.attr,
&dev_attr_sequence.attr,
+ &dev_attr_program.attr,
NULL,
};

diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
index 1683003..b68dee8 100644
--- a/include/linux/mfd/cros_ec_commands.h
+++ b/include/linux/mfd/cros_ec_commands.h
@@ -1158,6 +1158,13 @@ struct lightbar_params_v1 {
struct rgb_s color[8]; /* 0-3 are Google colors */
} __packed;

+/* Lightbar program */
+#define EC_LB_PROG_LEN 192
+struct lightbar_program {
+ uint8_t size;
+ uint8_t data[EC_LB_PROG_LEN];
+};
+
struct ec_params_lightbar {
uint8_t cmd; /* Command (see enum lightbar_command) */
union {
@@ -1184,6 +1191,7 @@ struct ec_params_lightbar {

struct lightbar_params_v0 set_params_v0;
struct lightbar_params_v1 set_params_v1;
+ struct lightbar_program set_program;
};
} __packed;

@@ -1216,7 +1224,8 @@ struct ec_response_lightbar {
struct {
/* no return params */
} off, on, init, set_brightness, seq, reg, set_rgb,
- demo, set_params_v0, set_params_v1;
+ demo, set_params_v0, set_params_v1,
+ set_program;
};
} __packed;

@@ -1240,6 +1249,7 @@ enum lightbar_command {
LIGHTBAR_CMD_GET_DEMO = 15,
LIGHTBAR_CMD_GET_PARAMS_V1 = 16,
LIGHTBAR_CMD_SET_PARAMS_V1 = 17,
+ LIGHTBAR_CMD_SET_PROGRAM = 18,
LIGHTBAR_NUM_CMDS
};

--
2.1.0