Re: [PATCH V3 3/3] interconnect: qcom: Add EPSS L3 support on SA8775P

[Dmitry Baryshkov]

On Sun, Nov 10, 2024 at 12:38:25PM +0000, Raviteja Laggyshetty wrote:
> Add Epoch Subsystem (EPSS) L3 interconnect provider support on
> SA8775P SoCs.
> 
> The EPSS instance in SA8775P uses PERF_STATE register instead of
> REG_L3_VOTE to scale L3 clocks. Add new generic compatible
> "qcom,epss-l3-perf" for PERF_STATE register based L3 scaling.

The patch does more than just ading a generic compatible. Please split
it into two parts. One adding a compat string, another one adding
support for multiple devices.

> 
> Signed-off-by: Raviteja Laggyshetty <quic_rlaggysh@xxxxxxxxxxx>
> ---
>  drivers/interconnect/qcom/osm-l3.c | 87 ++++++++++++++++++++++--------
>  1 file changed, 65 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/osm-l3.c b/drivers/interconnect/qcom/osm-l3.c
> index 6a656ed44d49..285afaa1f61e 100644
> --- a/drivers/interconnect/qcom/osm-l3.c
> +++ b/drivers/interconnect/qcom/osm-l3.c
> @@ -1,16 +1,19 @@
>  // SPDX-License-Identifier: GPL-2.0
>  /*
>   * Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
>   */
>  
>  #include <linux/args.h>
>  #include <linux/bitfield.h>
>  #include <linux/clk.h>
> +#include <linux/idr.h>
>  #include <linux/interconnect-provider.h>
>  #include <linux/io.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> +#include <linux/of_address.h>
>  #include <linux/platform_device.h>
>  
>  #include <dt-bindings/interconnect/qcom,osm-l3.h>
> @@ -34,9 +37,14 @@
>  
>  #define OSM_L3_MAX_LINKS		1
>  
> +#define OSM_L3_NODE_ID_START		10000
> +#define OSM_NODE_NAME_SUFFIX_SIZE	10
> +
>  #define to_osm_l3_provider(_provider) \
>  	container_of(_provider, struct qcom_osm_l3_icc_provider, provider)
>  
> +static DEFINE_IDA(osm_l3_id);
> +
>  struct qcom_osm_l3_icc_provider {
>  	void __iomem *base;
>  	unsigned int max_state;
> @@ -55,46 +63,40 @@ struct qcom_osm_l3_icc_provider {
>   */
>  struct qcom_osm_l3_node {
>  	const char *name;
> -	u16 links[OSM_L3_MAX_LINKS];
> +	const char *links[OSM_L3_MAX_LINKS];
>  	u16 id;
>  	u16 num_links;
>  	u16 buswidth;
>  };
>  
>  struct qcom_osm_l3_desc {
> -	const struct qcom_osm_l3_node * const *nodes;
> +	struct qcom_osm_l3_node * const *nodes;
>  	size_t num_nodes;
>  	unsigned int lut_row_size;
>  	unsigned int reg_freq_lut;
>  	unsigned int reg_perf_state;
>  };
>  
> -enum {
> -	OSM_L3_MASTER_NODE = 10000,
> -	OSM_L3_SLAVE_NODE,
> -};
> -
> -#define DEFINE_QNODE(_name, _id, _buswidth, ...)			\
> -	static const struct qcom_osm_l3_node _name = {			\
> +#define DEFINE_QNODE(_name, _buswidth, ...)				\
> +	static struct qcom_osm_l3_node _name = {			\
>  		.name = #_name,						\
> -		.id = _id,						\
>  		.buswidth = _buswidth,					\
>  		.num_links = COUNT_ARGS(__VA_ARGS__),			\
> -		.links = { __VA_ARGS__ },				\
> +		__VA_OPT__(.links = { #__VA_ARGS__ })			\
>  	}
>  
> -DEFINE_QNODE(osm_l3_master, OSM_L3_MASTER_NODE, 16, OSM_L3_SLAVE_NODE);
> -DEFINE_QNODE(osm_l3_slave, OSM_L3_SLAVE_NODE, 16);
> +DEFINE_QNODE(osm_l3_master, 16, osm_l3_slave);
> +DEFINE_QNODE(osm_l3_slave, 16);
>  
> -static const struct qcom_osm_l3_node * const osm_l3_nodes[] = {
> +static struct qcom_osm_l3_node * const osm_l3_nodes[] = {
>  	[MASTER_OSM_L3_APPS] = &osm_l3_master,
>  	[SLAVE_OSM_L3] = &osm_l3_slave,
>  };
>  
> -DEFINE_QNODE(epss_l3_master, OSM_L3_MASTER_NODE, 32, OSM_L3_SLAVE_NODE);
> -DEFINE_QNODE(epss_l3_slave, OSM_L3_SLAVE_NODE, 32);
> +DEFINE_QNODE(epss_l3_master, 32, epss_l3_slave);
> +DEFINE_QNODE(epss_l3_slave, 32);
>  
> -static const struct qcom_osm_l3_node * const epss_l3_nodes[] = {
> +static struct qcom_osm_l3_node * const epss_l3_nodes[] = {
>  	[MASTER_EPSS_L3_APPS] = &epss_l3_master,
>  	[SLAVE_EPSS_L3_SHARED] = &epss_l3_slave,
>  };
> @@ -123,6 +125,19 @@ static const struct qcom_osm_l3_desc epss_l3_l3_vote = {
>  	.reg_perf_state = EPSS_REG_L3_VOTE,
>  };
>  
> +static u16 get_node_id_by_name(const char *node_name,
> +			       const struct qcom_osm_l3_desc *desc)
> +{
> +	struct qcom_osm_l3_node *const *nodes = desc->nodes;
> +	int i;
> +
> +	for (i = 0; i < desc->num_nodes; i++) {
> +		if (!strcmp(nodes[i]->name, node_name))
> +			return nodes[i]->id;
> +	}
> +	return 0;
> +}
> +
>  static int qcom_osm_l3_set(struct icc_node *src, struct icc_node *dst)
>  {
>  	struct qcom_osm_l3_icc_provider *qp;
> @@ -164,10 +179,11 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
>  	const struct qcom_osm_l3_desc *desc;
>  	struct icc_onecell_data *data;
>  	struct icc_provider *provider;
> -	const struct qcom_osm_l3_node * const *qnodes;
> +	struct qcom_osm_l3_node * const *qnodes;
>  	struct icc_node *node;
>  	size_t num_nodes;
>  	struct clk *clk;
> +	u64 addr;
>  	int ret;
>  
>  	clk = clk_get(&pdev->dev, "xo");
> @@ -188,6 +204,10 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
>  	if (!qp)
>  		return -ENOMEM;
>  
> +	ret = of_property_read_reg(pdev->dev.of_node, 0, &addr, NULL);
> +	if (ret)
> +		return ret;
> +
>  	qp->base = devm_platform_ioremap_resource(pdev, 0);
>  	if (IS_ERR(qp->base))
>  		return PTR_ERR(qp->base);
> @@ -242,8 +262,13 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
>  
>  	icc_provider_init(provider);
>  
> +	/* Allocate unique id for qnodes */
> +	for (i = 0; i < num_nodes; i++)
> +		qnodes[i]->id = ida_alloc_min(&osm_l3_id, OSM_L3_NODE_ID_START, GFP_KERNEL);
> +
>  	for (i = 0; i < num_nodes; i++) {
> -		size_t j;
> +		char *node_name;
> +		size_t j, len;
>  
>  		node = icc_node_create(qnodes[i]->id);
>  		if (IS_ERR(node)) {
> @@ -251,13 +276,29 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
>  			goto err;
>  		}
>  
> -		node->name = qnodes[i]->name;
> +		/* len = strlen(node->name) + @ + 8 (base-address) + NULL */
> +		len = strlen(qnodes[i]->name) + OSM_NODE_NAME_SUFFIX_SIZE;
> +		node_name = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
> +		if (!node_name) {
> +			ret = -ENOMEM;
> +			goto err;
> +		}
> +
> +		snprintf(node_name, len, "%s@%08llx", qnodes[i]->name, addr);
> +		node->name = node_name;
> +
>  		/* Cast away const and add it back in qcom_osm_l3_set() */
>  		node->data = (void *)qnodes[i];
>  		icc_node_add(node, provider);
>  
> -		for (j = 0; j < qnodes[i]->num_links; j++)
> -			icc_link_create(node, qnodes[i]->links[j]);
> +		for (j = 0; j < qnodes[i]->num_links; j++) {
> +			u16 link_node_id = get_node_id_by_name(qnodes[i]->links[j], desc);
> +
> +			if (link_node_id)
> +				icc_link_create(node, link_node_id);
> +			else
> +				goto err;
> +		}
>  
>  		data->nodes[i] = node;
>  	}
> @@ -277,6 +318,7 @@ static int qcom_osm_l3_probe(struct platform_device *pdev)
>  
>  static const struct of_device_id osm_l3_of_match[] = {
>  	{ .compatible = "qcom,epss-l3", .data = &epss_l3_l3_vote },
> +	{ .compatible = "qcom,epss-l3-perf", .data = &epss_l3_perf_state },
>  	{ .compatible = "qcom,osm-l3", .data = &osm_l3 },
>  	{ .compatible = "qcom,sc7180-osm-l3", .data = &osm_l3 },
>  	{ .compatible = "qcom,sc7280-epss-l3", .data = &epss_l3_perf_state },
> @@ -284,6 +326,7 @@ static const struct of_device_id osm_l3_of_match[] = {
>  	{ .compatible = "qcom,sm8150-osm-l3", .data = &osm_l3 },
>  	{ .compatible = "qcom,sc8180x-osm-l3", .data = &osm_l3 },
>  	{ .compatible = "qcom,sm8250-epss-l3", .data = &epss_l3_perf_state },
> +	{ .compatible = "qcom,sa8775p-epss-l3", .data = &epss_l3_perf_state },
>  	{ }
>  };
>  MODULE_DEVICE_TABLE(of, osm_l3_of_match);
> -- 
> 2.39.2
> 

-- 
With best wishes
Dmitry