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

Lee Jones
2016-10-31T08:17:49Z

On Fri, 28 Oct 2016, Enric Balletbo i Serra wrote:

> From: Eric Caruso <ejcaruso@chromium.org>
>
> 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 +++++-

Acked-by: Lee Jones <lee.jones@linaro.org>

> 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
> };
>

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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