diff options
Diffstat (limited to 'drivers/interconnect/samsung/exynos.c')
| -rw-r--r-- | drivers/interconnect/samsung/exynos.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/drivers/interconnect/samsung/exynos.c b/drivers/interconnect/samsung/exynos.c new file mode 100644 index 000000000..72e426038 --- /dev/null +++ b/drivers/interconnect/samsung/exynos.c @@ -0,0 +1,199 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Exynos generic interconnect provider driver + * + * Copyright (c) 2020 Samsung Electronics Co., Ltd. + * + * Authors: Artur Świgoń <a.swigon@samsung.com> + * Sylwester Nawrocki <s.nawrocki@samsung.com> + */ +#include <linux/device.h> +#include <linux/interconnect-provider.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pm_qos.h> +#include <linux/slab.h> + +#define EXYNOS_ICC_DEFAULT_BUS_CLK_RATIO 8 + +struct exynos_icc_priv { + struct device *dev; + + /* One interconnect node per provider */ + struct icc_provider provider; + struct icc_node *node; + + struct dev_pm_qos_request qos_req; + u32 bus_clk_ratio; +}; + +static struct icc_node *exynos_icc_get_parent(struct device_node *np) +{ + struct of_phandle_args args; + struct icc_node_data *icc_node_data; + struct icc_node *icc_node; + int num, ret; + + num = of_count_phandle_with_args(np, "interconnects", + "#interconnect-cells"); + if (num < 1) + return NULL; /* parent nodes are optional */ + + /* Get the interconnect target node */ + ret = of_parse_phandle_with_args(np, "interconnects", + "#interconnect-cells", 0, &args); + if (ret < 0) + return ERR_PTR(ret); + + icc_node_data = of_icc_get_from_provider(&args); + of_node_put(args.np); + + if (IS_ERR(icc_node_data)) + return ERR_CAST(icc_node_data); + + icc_node = icc_node_data->node; + kfree(icc_node_data); + + return icc_node; +} + +static int exynos_generic_icc_set(struct icc_node *src, struct icc_node *dst) +{ + struct exynos_icc_priv *src_priv = src->data, *dst_priv = dst->data; + s32 src_freq = max(src->avg_bw, src->peak_bw) / src_priv->bus_clk_ratio; + s32 dst_freq = max(dst->avg_bw, dst->peak_bw) / dst_priv->bus_clk_ratio; + int ret; + + ret = dev_pm_qos_update_request(&src_priv->qos_req, src_freq); + if (ret < 0) { + dev_err(src_priv->dev, "failed to update PM QoS of %s (src)\n", + src->name); + return ret; + } + + ret = dev_pm_qos_update_request(&dst_priv->qos_req, dst_freq); + if (ret < 0) { + dev_err(dst_priv->dev, "failed to update PM QoS of %s (dst)\n", + dst->name); + return ret; + } + + return 0; +} + +static struct icc_node *exynos_generic_icc_xlate(struct of_phandle_args *spec, + void *data) +{ + struct exynos_icc_priv *priv = data; + + if (spec->np != priv->dev->parent->of_node) + return ERR_PTR(-EINVAL); + + return priv->node; +} + +static int exynos_generic_icc_remove(struct platform_device *pdev) +{ + struct exynos_icc_priv *priv = platform_get_drvdata(pdev); + struct icc_node *parent_node, *node = priv->node; + + icc_provider_deregister(&priv->provider); + + parent_node = exynos_icc_get_parent(priv->dev->parent->of_node); + if (parent_node && !IS_ERR(parent_node)) + icc_link_destroy(node, parent_node); + + icc_nodes_remove(&priv->provider); + + return 0; +} + +static int exynos_generic_icc_probe(struct platform_device *pdev) +{ + struct device *bus_dev = pdev->dev.parent; + struct exynos_icc_priv *priv; + struct icc_provider *provider; + struct icc_node *icc_node, *icc_parent_node; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->dev = &pdev->dev; + platform_set_drvdata(pdev, priv); + + provider = &priv->provider; + + provider->set = exynos_generic_icc_set; + provider->aggregate = icc_std_aggregate; + provider->xlate = exynos_generic_icc_xlate; + provider->dev = bus_dev; + provider->inter_set = true; + provider->data = priv; + + icc_provider_init(provider); + + icc_node = icc_node_create(pdev->id); + if (IS_ERR(icc_node)) + return PTR_ERR(icc_node); + + priv->node = icc_node; + icc_node->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOFn", + bus_dev->of_node); + if (of_property_read_u32(bus_dev->of_node, "samsung,data-clock-ratio", + &priv->bus_clk_ratio)) + priv->bus_clk_ratio = EXYNOS_ICC_DEFAULT_BUS_CLK_RATIO; + + icc_node->data = priv; + icc_node_add(icc_node, provider); + + /* + * Register a PM QoS request for the parent (devfreq) device. + */ + ret = dev_pm_qos_add_request(bus_dev, &priv->qos_req, + DEV_PM_QOS_MIN_FREQUENCY, 0); + if (ret < 0) + goto err_node_del; + + icc_parent_node = exynos_icc_get_parent(bus_dev->of_node); + if (IS_ERR(icc_parent_node)) { + ret = PTR_ERR(icc_parent_node); + goto err_pmqos_del; + } + if (icc_parent_node) { + ret = icc_link_create(icc_node, icc_parent_node->id); + if (ret < 0) + goto err_pmqos_del; + } + + ret = icc_provider_register(provider); + if (ret < 0) + goto err_pmqos_del; + + return 0; + +err_pmqos_del: + dev_pm_qos_remove_request(&priv->qos_req); +err_node_del: + icc_nodes_remove(provider); + + return ret; +} + +static struct platform_driver exynos_generic_icc_driver = { + .driver = { + .name = "exynos-generic-icc", + .sync_state = icc_sync_state, + }, + .probe = exynos_generic_icc_probe, + .remove = exynos_generic_icc_remove, +}; +module_platform_driver(exynos_generic_icc_driver); + +MODULE_DESCRIPTION("Exynos generic interconnect driver"); +MODULE_AUTHOR("Artur Świgoń <a.swigon@samsung.com>"); +MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:exynos-generic-icc"); |