Re: [PATCH v5 01/14] coresight: cti: Initial CoreSight CTI Driver

[Suzuki Kuruppassery Poulose <suzuki.poulose@arm.com>]

On 19/11/2019 23:18, Mike Leach wrote:
> This introduces a baseline CTI driver and associated configuration files.
> 
> Uses the platform agnostic naming standard for CoreSight devices, along
> with a generic platform probing method that currently supports device
> tree descriptions, but allows for the ACPI bindings to be added once these
> have been defined for the CTI devices.
> 
> Driver will probe for the device on the AMBA bus, and load the CTI driver
> on CoreSight ID match to CTI IDs in tables.
> 
> Initial sysfs support for enable / disable provided.
> 
> Default CTI interconnection data is generated based on hardware
> register signal counts, with no additional connection information.
> 
> Signed-off-by: Mike Leach <mike.leach@linaro.org>

Looks good to me.  Some very minor nits, feel free to ignore if you are 
not respinning the series.

> +/*
> + * Look at the HW DEVID register for some of the HW settings.
> + * DEVID[15:8] - max number of in / out triggers.
> + */
> +#define CTI_DEVID_MAXTRIGS(devid_val) (int)((devid_val & 0xFF00) >> 8)

BMVAL(devid_val, 15, 8)

> +
> +/* DEVID[19:16] - number of CTM channels */
> +#define CTI_DEVID_CTMCHANNELS(devid_val) (int)((devid_val & 0xF0000) >> 16)

BMVAL(devid_val, 19, 16)

> +
> +static void cti_set_default_config(struct device *dev,
> +				   struct cti_drvdata *drvdata)
> +{
> +	struct cti_config *config = &drvdata->config;
> +	u32 devid;
> +
> +	devid = readl_relaxed(drvdata->base + CORESIGHT_DEVID);
> +	config->nr_trig_max = CTI_DEVID_MAXTRIGS(devid);
> +
> +	/*
> +	 * no current hardware should exceed this, but protect the driver
> +	 * in case of fault / out of spec hw
> +	 */
> +	if (config->nr_trig_max > CTIINOUTEN_MAX) {
> +		dev_warn_once(dev,
> +			"Limiting HW MaxTrig value(%d) to driver max(%d)\n",
> +			config->nr_trig_max, CTIINOUTEN_MAX);
> +		config->nr_trig_max = CTIINOUTEN_MAX;
> +	}
> +
> +	config->nr_ctm_channels = CTI_DEVID_CTMCHANNELS(devid);
> +
> +	/* Most regs default to 0 as zalloc'ed except...*/
> +	config->trig_filter_enable = true;
> +	config->ctigate = GENMASK(config->nr_ctm_channels - 1, 0);
> +	atomic_set(&config->enable_req_count, 0);
> +}
> +
> +/*
> + * Add a connection entry to the list of connections for this
> + * CTI device.
> + */
> +int cti_add_connection_entry(struct device *dev, struct cti_drvdata *drvdata,
> +			     struct cti_trig_con *tc,
> +			     struct coresight_device *csdev,
> +			     const char *assoc_dev_name)
> +{
> +	struct cti_device *cti_dev = &drvdata->ctidev;
> +
> +	tc->con_dev = csdev;
> +	/*
> +	 * Prefer actual associated CS device dev name to supplied value -
> +	 * which is likely to be node name / other conn name.
> +	 */
> +	if (csdev)
> +		tc->con_dev_name = devm_kstrdup(dev,
> +						dev_name(&csdev->dev),
> +						GFP_KERNEL);
> +	else if (assoc_dev_name != NULL)
> +		tc->con_dev_name = devm_kstrdup(dev,
> +						assoc_dev_name, GFP_KERNEL);
> +	list_add_tail(&tc->node, &cti_dev->trig_cons);
> +	cti_dev->nr_trig_con++;
> +
> +	/* add connection usage bit info to overall info */
> +	drvdata->config.trig_in_use |= tc->con_in->used_mask;
> +	drvdata->config.trig_out_use |= tc->con_out->used_mask;

Do we need to make sure that they are exclusive ?

  WARN_ON(drvdata->config.trig_in_use ^ ~(tc->con_in->used_mask));
  WARN_ON(drvdata->config.trig_out_use ^ ~(tc->con_out->used_mask));

> +/** cti ect operations **/
> +int cti_enable(struct coresight_device *csdev)
> +{
> +	struct cti_drvdata *drvdata = csdev_to_cti_drvdata(csdev);
> +
> +	/* enable hardware with refcount */

nit: left over comment from previous revision ?

> +	return cti_enable_hw(drvdata);
> +}
> +
> +int cti_disable(struct coresight_device *csdev)
> +{
> +	struct cti_drvdata *drvdata = csdev_to_cti_drvdata(csdev);
> +
> +	/* disable hardware with refcount */

same here ?

> +	return cti_disable_hw(drvdata);
> +}
> +

> +
> +static int cti_probe(struct amba_device *adev, const struct amba_id *id)
> +{
> +	int ret = 0;
> +	void __iomem *base;
> +	struct device *dev = &adev->dev;
> +	struct cti_drvdata *drvdata = NULL;
> +	struct coresight_desc cti_desc;
> +	struct coresight_platform_data *pdata = NULL;
> +	struct resource *res = &adev->res;
> +
> +	/* driver data*/
> +	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
> +	if (!drvdata) {
> +		ret = -ENOMEM;
> +		dev_info(dev, "%s, mem err\n", __func__);

dev_err() ? As they may have higher priority than "info" and will get
displayed in the rare chance of them getting hit.

> +		goto err_out;
> +	}
> +
> +	/* Validity for the resource is already checked by the AMBA core */
> +	base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(base)) {
> +		ret = PTR_ERR(base);
> +		dev_info(dev, "%s, remap err\n", __func__);

same here, dev_err()

> +		goto err_out;
> +	}
> +	drvdata->base = base;
> +
> +	dev_set_drvdata(dev, drvdata);
> +
> +	/* default CTI device info  */
> +	drvdata->ctidev.cpu = -1;
> +	drvdata->ctidev.nr_trig_con = 0;
> +	drvdata->ctidev.ctm_id = 0;
> +	INIT_LIST_HEAD(&drvdata->ctidev.trig_cons);
> +
> +	spin_lock_init(&drvdata->spinlock);
> +
> +	/* initialise CTI driver config values */
> +	cti_set_default_config(dev, drvdata);
> +
> +	/* Parse the .dts for connections and signals */

minor nit: I would not mention about ".dts" here. The function name is
implicit. You could actually remove that comment.

As mentioned above, the comments are minor nits. So you may add
with/without addressing them:

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>