Re: [PATCH 3/5] clk: qcom: cbf-msm8996: scale CBF clock according to the CPUfreq

[Konrad Dybcio <konrad.dybcio@linaro.org>]

On 11.01.2023 20:57, Dmitry Baryshkov wrote:
> Turn CBF into the interconnect provider. Scale CBF frequency (bandwidth)
> according to CPU frequencies.
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
TODO: assess if we should be doing this manually or rely on SPDM..

Konrad
>  drivers/clk/qcom/clk-cbf-8996.c | 141 +++++++++++++++++++++++++++++++-
>  1 file changed, 140 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/qcom/clk-cbf-8996.c b/drivers/clk/qcom/clk-cbf-8996.c
> index bdd4f8b48a7e..76db623b0f92 100644
> --- a/drivers/clk/qcom/clk-cbf-8996.c
> +++ b/drivers/clk/qcom/clk-cbf-8996.c
> @@ -5,6 +5,7 @@
>  #include <linux/bitfield.h>
>  #include <linux/clk.h>
>  #include <linux/clk-provider.h>
> +#include <linux/interconnect-provider.h>
>  #include <linux/of.h>
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
> @@ -225,6 +226,133 @@ static const struct regmap_config cbf_msm8996_regmap_config = {
>  	.val_format_endian	= REGMAP_ENDIAN_LITTLE,
>  };
>  
> +#ifdef CONFIG_INTERCONNECT
> +struct qcom_msm8996_cbf_icc_provider {
> +	struct icc_provider provider;
> +	struct clk *clk;
> +};
> +
> +#define to_qcom_cbf_provider(_provider) \
> +	container_of(_provider, struct qcom_msm8996_cbf_icc_provider, provider)
> +
> +enum {
> +	CBF_MASTER_NODE = 2000,
> +	CBF_SLAVE_NODE
> +};
> +
> +#define CBF_NUM_NODES 2
> +
> +static int qcom_msm8996_cbf_set(struct icc_node *src, struct icc_node *dst)
> +{
> +	struct qcom_msm8996_cbf_icc_provider *qp;
> +
> +	qp = to_qcom_cbf_provider(src->provider);
> +
> +	return clk_set_rate(qp->clk, icc_units_to_bps(dst->peak_bw));
> +}
> +
> +static int qcom_msm8996_cbf_icc_get_bw(struct icc_node *node, u32 *avg, u32 *peak)
> +{
> +	struct qcom_msm8996_cbf_icc_provider *qp;
> +
> +	qp = to_qcom_cbf_provider(node->provider);
> +	*peak = clk_get_rate(qp->clk) / 1000ULL;
> +
> +	return 0;
> +}
> +
> +static int qcom_msm8996_cbf_icc_register(struct platform_device *pdev, struct clk_hw *cbf_hw)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct qcom_msm8996_cbf_icc_provider *qp;
> +	struct icc_provider *provider;
> +	struct icc_onecell_data *data;
> +	struct icc_node *node;
> +	struct clk *clk;
> +	int ret;
> +
> +	clk = devm_clk_hw_get_clk(dev, cbf_hw, "cbf");
> +	if (IS_ERR(clk))
> +		return PTR_ERR(clk);
> +
> +	data = devm_kzalloc(dev, struct_size(data, nodes, CBF_NUM_NODES), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->num_nodes = CBF_NUM_NODES;
> +
> +	qp = devm_kzalloc(dev, sizeof(*qp), GFP_KERNEL);
> +	if (!qp)
> +		return -ENOMEM;
> +
> +	qp->clk = clk;
> +
> +	provider = &qp->provider;
> +	provider->dev = dev;
> +	provider->get_bw = qcom_msm8996_cbf_icc_get_bw;
> +	provider->set = qcom_msm8996_cbf_set;
> +	provider->aggregate = icc_std_aggregate;
> +	provider->xlate = of_icc_xlate_onecell;
> +	INIT_LIST_HEAD(&provider->nodes);
> +	provider->data = data;
> +
> +	ret = icc_provider_add(provider);
> +	if (ret) {
> +		dev_err(dev, "error adding interconnect provider\n");
> +		return ret;
> +	}
> +
> +	node = icc_node_create(CBF_MASTER_NODE);
> +	if (IS_ERR(node)) {
> +		ret = PTR_ERR(node);
> +		goto err;
> +	}
> +
> +	node->name = "cbf_master";
> +	icc_node_add(node, provider);
> +	icc_link_create(node, CBF_SLAVE_NODE);
> +	data->nodes[0] = node;
> +
> +	node = icc_node_create(CBF_SLAVE_NODE);
> +	if (IS_ERR(node)) {
> +		ret = PTR_ERR(node);
> +		goto err;
> +	}
> +
> +	node->name = "cbf_slave";
> +	icc_node_add(node, provider);
> +	data->nodes[1] = node;
> +
> +	platform_set_drvdata(pdev, provider);
> +
> +	return 0;
> +
> +err:
> +	icc_nodes_remove(provider);
> +	icc_provider_del(provider);
> +
> +	return ret;
> +}
> +
> +static int qcom_msm8996_cbf_icc_remove(struct platform_device *pdev)
> +{
> +	struct icc_provider *provider = platform_get_drvdata(pdev);
> +
> +	icc_nodes_remove(provider);
> +	icc_provider_del(provider);
> +
> +	return 0;
> +}
> +#else
> +static int qcom_msm8996_cbf_icc_register(struct platform_device *pdev)
> +{
> +	dev_warn(&pdev->dev, "interconnects support is disabled, CBF clock is fixed\n");
> +
> +	return 0;
> +}
> +#define qcom_msm8996_cbf_icc_remove(pdev) (0)
> +#endif
> +
>  static int qcom_msm8996_cbf_probe(struct platform_device *pdev)
>  {
>  	void __iomem *base;
> @@ -284,7 +412,16 @@ static int qcom_msm8996_cbf_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> -	return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, &cbf_mux.clkr.hw);
> +	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, &cbf_mux.clkr.hw);
> +	if (ret)
> +		return ret;
> +
> +	return qcom_msm8996_cbf_icc_register(pdev, &cbf_mux.clkr.hw);
> +}
> +
> +static int qcom_msm8996_cbf_remove(struct platform_device *pdev)
> +{
> +	return qcom_msm8996_cbf_icc_remove(pdev);
>  }
>  
>  static const struct of_device_id qcom_msm8996_cbf_match_table[] = {
> @@ -295,9 +432,11 @@ MODULE_DEVICE_TABLE(of, qcom_msm8996_cbf_match_table);
>  
>  static struct platform_driver qcom_msm8996_cbf_driver = {
>  	.probe = qcom_msm8996_cbf_probe,
> +	.remove = qcom_msm8996_cbf_remove,
>  	.driver = {
>  		.name = "qcom-msm8996-cbf",
>  		.of_match_table = qcom_msm8996_cbf_match_table,
> +		.sync_state = icc_sync_state,
>  	},
>  };
>