Subject: Re: [RFCv3 2/3] interconnect: Add imx core driver

From: Georgi Djakov <[email-masked]>
Date: Wed, 7 Aug 2019 18:16:50 +0300

Hi Leonard,

On 8/6/19 13:55, Leonard Crestez wrote:
> This adds support for i.MX SoC family to interconnect framework.
> 
> Platform drivers can describe their interconnect graph and
> several adjustment knobs where an icc node bandwith converted to a

s/bandwith/bandwidth/

> clk_min_rate request.
> 
> All adjustable nodes are assumed to be independent.
> 
> Based on an earlier work by Alexandre Bailon but greatly reduced to drop
> "platform opp" support.
> 
> Signed-off-by: Leonard Crestez <[email-masked]>
> Signed-off-by: Alexandre Bailon <[email-masked]>

Your Signed-off-by should be below Alexandre's.

> ---
>  drivers/interconnect/Kconfig      |   1 +
>  drivers/interconnect/Makefile     |   1 +
>  drivers/interconnect/imx/Kconfig  |   5 +
>  drivers/interconnect/imx/Makefile |   1 +
>  drivers/interconnect/imx/imx.c    | 258 ++++++++++++++++++++++++++++++
>  drivers/interconnect/imx/imx.h    |  62 +++++++
>  6 files changed, 328 insertions(+)
>  create mode 100644 drivers/interconnect/imx/Kconfig
>  create mode 100644 drivers/interconnect/imx/Makefile
>  create mode 100644 drivers/interconnect/imx/imx.c
>  create mode 100644 drivers/interconnect/imx/imx.h
> 
> diff --git a/drivers/interconnect/Kconfig b/drivers/interconnect/Kconfig
> index bfa4ca3ab7a9..e61802230f90 100644
> --- a/drivers/interconnect/Kconfig
> +++ b/drivers/interconnect/Kconfig
> @@ -10,7 +10,8 @@ menuconfig INTERCONNECT
>  	  If unsure, say no.
>  
>  if INTERCONNECT
>  
>  source "drivers/interconnect/qcom/Kconfig"
> +source "drivers/interconnect/imx/Kconfig"
>  
>  endif
> diff --git a/drivers/interconnect/Makefile b/drivers/interconnect/Makefile
> index 28f2ab0824d5..20a13b7eb37f 100644
> --- a/drivers/interconnect/Makefile
> +++ b/drivers/interconnect/Makefile
> @@ -2,5 +2,6 @@
>  
>  icc-core-objs				:= core.o
>  
>  obj-$(CONFIG_INTERCONNECT)		+= icc-core.o
>  obj-$(CONFIG_INTERCONNECT_QCOM)		+= qcom/
> +obj-$(CONFIG_INTERCONNECT_IMX)		+= imx/
> diff --git a/drivers/interconnect/imx/Kconfig b/drivers/interconnect/imx/Kconfig
> new file mode 100644
> index 000000000000..45fbae7007af
> --- /dev/null
> +++ b/drivers/interconnect/imx/Kconfig
> @@ -0,0 +1,5 @@
> +config INTERCONNECT_IMX
> +	bool "i.MX interconnect drivers"
> +	depends on ARCH_MXC || ARCH_MXC_ARM64 || COMPILE_TEST
> +	help
> +	  Generic interconnect driver for i.MX SOCs
> diff --git a/drivers/interconnect/imx/Makefile b/drivers/interconnect/imx/Makefile
> new file mode 100644
> index 000000000000..bb92fd9fe4a5
> --- /dev/null
> +++ b/drivers/interconnect/imx/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_INTERCONNECT_IMX) += imx.o
> diff --git a/drivers/interconnect/imx/imx.c b/drivers/interconnect/imx/imx.c
> new file mode 100644
> index 000000000000..cc838e40419e
> --- /dev/null
> +++ b/drivers/interconnect/imx/imx.c
> @@ -0,0 +1,258 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Interconnect framework driver for i.MX SoC
> + *
> + * Copyright (c) 2019, BayLibre
> + * Copyright (c) 2019, NXP
> + * Author: Alexandre Bailon <[email-masked]>
> + * Author: Leonard Crestez <[email-masked]>
> + */
> +
> +#include <linux/device.h>
> +#include <linux/interconnect-provider.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_qos.h>
> +#include <linux/devfreq.h>

Please sort alphabetically.

> +#include <linux/of.h>
> +
> +#include "imx.h"
> +
> +/* private icc_provider data */
> +struct imx_icc_provider {
> +	struct device *dev;
> +};
> +
> +/* private icc_node data */
> +struct imx_icc_node {
> +	const struct imx_icc_node_desc *desc;
> +	struct devfreq *devfreq;
> +	struct dev_pm_qos_request qos_req;
> +};
> +
> +static int imx_icc_aggregate(struct icc_node *node, u32 avg_bw,
> +				  u32 peak_bw, u32 *agg_avg, u32 *agg_peak)
> +{
> +	*agg_avg += avg_bw;
> +	*agg_peak = max(*agg_peak, peak_bw);
> +
> +	return 0;
> +}
> +
> +static struct icc_node* imx_icc_xlate(struct of_phandle_args *spec, void *data)
> +{
> +	struct imx_icc_provider *desc = data;
> +	struct icc_provider *provider = dev_get_drvdata(desc->dev);
> +	unsigned int id = spec->args[0];
> +	struct icc_node *node;
> +
> +	list_for_each_entry (node, &provider->nodes, node_list)
> +		if (node->id == id)
> +			return node;
> +
> +	return ERR_PTR(-EINVAL);
> +}
> +
> +static int imx_icc_node_set(struct icc_node *node)
> +{
> +	struct device *dev = node->provider->dev;
> +	struct imx_icc_node *node_data = node->data;
> +	unsigned long freq;
> +
> +	if (!node_data->devfreq)
> +		return 0;
> +
> +	freq = (node->avg_bw + node->peak_bw) * node_data->desc->adj->bw_mul;
> +	do_div(freq, node_data->desc->adj->bw_div);
> +	if (freq > INT_MAX) {
> +		dev_err(dev, "%s can't request more INT_MAX freq\n",
> +				node->name);
> +		return -ERANGE;
> +	}
> +
> +	dev_dbg(dev, "%s avg_bw %u peak_bw %u min_freq %lu\n",
> +			node->name, node->avg_bw, node->peak_bw, freq);
> +
> +	dev_pm_qos_update_request(&node_data->qos_req, freq);
> +
> +	return 0;
> +}
> +
> +static int imx_icc_set(struct icc_node *src, struct icc_node *dst)
> +{
> +	return imx_icc_node_set(dst);
> +}
> +
> +static int imx_icc_node_init_devfreq(struct device *dev, 
> +				     struct icc_node *node)
> +{
> +	struct imx_icc_node *node_data = node->data;
> +	const struct imx_icc_node_desc *node_desc = node_data->desc;
> +	int index;
> +	int ret;
> +
> +	index = of_property_match_string(dev->of_node,
> +			"devfreq-names", node_desc->adj->devfreq_name);
> +	if (index < 0) {
> +		dev_err(dev, "failed to match devfreq-names %s: %d\n",
> +				node_desc->adj->devfreq_name, index);
> +		return index;
> +	}
> +
> +	node_data->devfreq = devfreq_get_devfreq_by_phandle(dev, index);
> +	if (IS_ERR(node_data->devfreq)) {
> +		ret = PTR_ERR(node_data->devfreq);
> +		if (ret != -EPROBE_DEFER)
> +			dev_err(dev, "failed to fetch devfreq %d %s: %d\n",
> +					index, node_desc->adj->devfreq_name, ret);
> +		return ret;
> +	}
> +
> +	return dev_pm_qos_add_request(node_data->devfreq->dev.parent,
> +			&node_data->qos_req,
> +			DEV_PM_QOS_MIN_FREQUENCY, 0);
> +}
> +
> +static struct icc_node *imx_icc_node_add(struct icc_provider *provider,
> +					 const struct imx_icc_node_desc *node_desc)
> +{
> +	struct imx_icc_provider *provider_data = provider->data;
> +	struct device *dev = provider_data->dev;
> +	struct imx_icc_node *node_data;
> +	struct icc_node *node;
> +	int ret;
> +
> +	node = icc_node_create(node_desc->id);
> +	if (IS_ERR(node)) {
> +		dev_err(dev, "failed to create node %d\n", node_desc->id);
> +		return node;
> +	}
> +
> +	if (node->data) {
> +		dev_err(dev, "already created node %s id=%d\n",
> +				node_desc->name, node_desc->id);
> +		return ERR_PTR(-EEXIST);
> +	}
> +
> +	node_data = devm_kzalloc(dev, sizeof(*node_data), GFP_KERNEL);
> +	if (!node_data) {
> +		icc_node_destroy(node->id);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	node->name = node_desc->name;
> +	node->data = node_data;
> +	node_data->desc = node_desc;
> +	if (node_desc->adj) {
> +		ret = imx_icc_node_init_devfreq(dev, node);
> +		if (ret < 0) {
> +			icc_node_destroy(node->id);
> +			return ERR_PTR(ret);
> +		}
> +	}
> +
> +	icc_node_add(node, provider);
> +
> +	return node;
> +}
> +
> +static void imx_icc_unregister_nodes(struct icc_provider *provider)
> +{
> +	struct icc_node *node, *tmp;
> +
> +	list_for_each_entry_safe(node, tmp, &provider->nodes, node_list) {
> +		struct imx_icc_node *node_data = node->data;
> +
> +		icc_node_del(node);
> +		icc_node_destroy(node->id);
> +		if (dev_pm_qos_request_active(&node_data->qos_req))
> +			dev_pm_qos_remove_request(&node_data->qos_req);
> +	}
> +}
> +
> +static int imx_icc_register_nodes(struct icc_provider *provider,
> +				  const struct imx_icc_node_desc *descs,
> +				  int count)
> +{
> +	int ret;
> +	int i;
> +
> +	for (i = 0; i < count; i++) {
> +		struct icc_node *node;
> +		const struct imx_icc_node_desc *node_desc = &descs[i];
> +		size_t j;
> +
> +		node = imx_icc_node_add(provider, node_desc);
> +		if (IS_ERR(node)) {
> +			ret = PTR_ERR(node);
> +			if (ret != -EPROBE_DEFER)
> +				dev_err(provider->dev, "failed to add %s: %d\n",
> +						node_desc->name, ret);
> +			goto err;
> +		}
> +
> +		for (j = 0; j < node_desc->num_links; j++)
> +			icc_link_create(node, node_desc->links[j]);
> +	}
> +
> +	return 0;
> +
> +err:
> +	imx_icc_unregister_nodes(provider);
> +
> +	return ret;
> +}
> +
> +int imx_icc_register(struct platform_device *pdev,
> +		     struct imx_icc_node_desc *nodes, int nodes_count)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct imx_icc_provider *desc;
> +	struct icc_provider *provider;
> +	int ret;
> +
> +	desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
> +	if (!desc)
> +		return -ENOMEM;
> +	desc->dev = dev;
> +
> +	provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
> +	if (!provider)
> +		return -ENOMEM;
> +	provider->set = imx_icc_set;
> +	provider->aggregate = imx_icc_aggregate;
> +	provider->xlate = imx_icc_xlate;
> +	provider->data = desc;
> +	provider->dev = dev;
> +	platform_set_drvdata(pdev, provider);
> +
> +	ret = icc_provider_add(provider);
> +	if (ret) {
> +		dev_err(dev, "error adding interconnect provider\n");
> +		return ret;
> +	}
> +
> +	ret = imx_icc_register_nodes(provider, nodes, nodes_count);
> +	if (ret) {
> +		dev_err(dev, "error adding interconnect nodes\n");
> +		goto provider_del;
> +	}
> +
> +	return 0;
> +
> +provider_del:
> +	icc_provider_del(provider);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(imx_icc_register);
> +
> +int imx_icc_unregister(struct platform_device *pdev)
> +{
> +	struct icc_provider *provider = platform_get_drvdata(pdev);
> +
> +	icc_provider_del(provider);
> +	imx_icc_unregister_nodes(provider);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(imx_icc_unregister);
> diff --git a/drivers/interconnect/imx/imx.h b/drivers/interconnect/imx/imx.h
> new file mode 100644
> index 000000000000..ab191eb89616
> --- /dev/null
> +++ b/drivers/interconnect/imx/imx.h
> @@ -0,0 +1,62 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Interconnect framework driver for i.MX SoC
> + *
> + * Copyright (c) 2019, BayLibre
> + * Copyright (c) 2019, NXP
> + * Author: Alexandre Bailon <[email-masked]>
> + * Author: Leonard Crestez <[email-masked]>
> + */
> +#ifndef __BUSFREQ_H
> +#define __BUSFREQ_H

Maybe __DRIVERS_INTERCONNECT_IMX_IMX_H to match with the path and filename.

> +
> +#include <linux/kernel.h>
> +
> +#define IMX_ICC_MAX_LINKS	32

2 seems enough?

> +#define IMX_ICC_UNDEFINED_BW	0xffffffff

Is this used?

> +
> +/*
> + * struct imx_icc_node_adj - Describe an dynamic adjustment knob

s/an/a/

> + */
> +struct imx_icc_node_adj_desc {
> +	const char *devfreq_name;
> +	unsigned int bw_mul, bw_div;
> +};
> +
> +/*
> + * struct imx_icc_node - Describe an interconnect node
> + * @name: name of the node
> + * @id: an unique id to identify the node
> + * @links: an array of slaves' node id
> + * @num_links: number of id defined in links
> + */
> +struct imx_icc_node_desc {
> +	const char *name;
> +	u16 id;
> +	u16 links[IMX_ICC_MAX_LINKS];
> +	u16 num_links;
> +
> +	const struct imx_icc_node_adj_desc *adj;
> +};
> +
> +#define DEFINE_BUS_INTERCONNECT(_name, _id, _adj, _numlinks, ...)	\

You can remove the _numlinks...

> +	{								\
> +		.id = _id,						\
> +		.name = _name,						\
> +		.adj = _adj,						\
> +		.num_links = _numlinks,					\

...and calculate the number of links automatically with:
		.num_links = ARRAY_SIZE(((int[]){ __VA_ARGS__ })),	\

> +		.links = { __VA_ARGS__ },				\
> +	}
> +
> +#define DEFINE_BUS_MASTER(_name, _id, _dest_id)				\
> +	DEFINE_BUS_INTERCONNECT(_name, _id, NULL, 1, _dest_id)
> +
> +#define DEFINE_BUS_SLAVE(_name, _id, _adj)				\
> +	DEFINE_BUS_INTERCONNECT(_name, _id, _adj, 0)
> +
> +int imx_icc_register(struct platform_device *pdev,
> +		     struct imx_icc_node_desc *nodes,
> +		     int nodes_count);
> +int imx_icc_unregister(struct platform_device *pdev);
> +
> +#endif /* __BUSFREQ_H */
Thanks,
Georgi

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