Hi Sylwester,
On Sat, May 30, 2020 at 1:34 AM Sylwester Nawrocki s.nawrocki@samsung.com wrote:
This patch adds a generic interconnect driver for Exynos SoCs in order to provide interconnect functionality for each "samsung,exynos-bus" compatible device.
The SoC topology is a graph (or more specifically, a tree) and its edges are specified using the 'samsung,interconnect-parent' in the DT. Due to unspecified relative probing order, -EPROBE_DEFER may be propagated to ensure that the parent is probed before its children.
Each bus is now an interconnect provider and an interconnect node as well (cf. Documentation/interconnect/interconnect.rst), i.e. every bus registers itself as a node. Node IDs are not hardcoded but rather assigned dynamically at runtime. This approach allows for using this driver with various Exynos SoCs.
Frequencies requested via the interconnect API for a given node are propagated to devfreq using dev_pm_qos_update_request(). Please note that it is not an error when CONFIG_INTERCONNECT is 'n', in which case all interconnect API functions are no-op.
Signed-off-by: Artur Świgoń a.swigon@samsung.com Signed-off-by: Sylwester Nawrocki s.nawrocki@samsung.com
Changes for v5:
- adjust to renamed exynos,interconnect-parent-node property,
- use automatically generated platform device id as the interconect node id instead of a now unavailable devfreq->id field,
- add icc_ prefix to some variables to make the code more self-commenting,
- use icc_nodes_remove() instead of icc_node_del() + icc_node_destroy(),
- adjust to exynos,interconnect-parent-node property rename to samsung,interconnect-parent,
- converted to a separate platform driver in drivers/interconnect.
drivers/interconnect/Kconfig | 1 + drivers/interconnect/Makefile | 1 + drivers/interconnect/exynos/Kconfig | 6 ++ drivers/interconnect/exynos/Makefile | 4 + drivers/interconnect/exynos/exynos.c | 185 +++++++++++++++++++++++++++++++++++ 5 files changed, 197 insertions(+) create mode 100644 drivers/interconnect/exynos/Kconfig create mode 100644 drivers/interconnect/exynos/Makefile create mode 100644 drivers/interconnect/exynos/exynos.c
diff --git a/drivers/interconnect/Kconfig b/drivers/interconnect/Kconfig index 5b7204e..eca6eda 100644 --- a/drivers/interconnect/Kconfig +++ b/drivers/interconnect/Kconfig @@ -11,6 +11,7 @@ menuconfig INTERCONNECT
if INTERCONNECT
+source "drivers/interconnect/exynos/Kconfig" source "drivers/interconnect/imx/Kconfig" source "drivers/interconnect/qcom/Kconfig"
diff --git a/drivers/interconnect/Makefile b/drivers/interconnect/Makefile index 4825c28..2ba1de6 100644 --- a/drivers/interconnect/Makefile +++ b/drivers/interconnect/Makefile @@ -4,5 +4,6 @@ CFLAGS_core.o := -I$(src) icc-core-objs := core.o
obj-$(CONFIG_INTERCONNECT) += icc-core.o +obj-$(CONFIG_INTERCONNECT_EXYNOS) += exynos/ obj-$(CONFIG_INTERCONNECT_IMX) += imx/ obj-$(CONFIG_INTERCONNECT_QCOM) += qcom/ diff --git a/drivers/interconnect/exynos/Kconfig b/drivers/interconnect/exynos/Kconfig new file mode 100644 index 0000000..e51e52e --- /dev/null +++ b/drivers/interconnect/exynos/Kconfig @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0-only +config INTERCONNECT_EXYNOS
tristate "Exynos generic interconnect driver"depends on ARCH_EXYNOS || COMPILE_TESThelpGeneric interconnect driver for Exynos SoCs.diff --git a/drivers/interconnect/exynos/Makefile b/drivers/interconnect/exynos/Makefile new file mode 100644 index 0000000..e19d1df --- /dev/null +++ b/drivers/interconnect/exynos/Makefile @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 +exynos-interconnect-objs := exynos.o
+obj-$(CONFIG_INTERCONNECT_EXYNOS) += exynos-interconnect.o diff --git a/drivers/interconnect/exynos/exynos.c b/drivers/interconnect/exynos/exynos.c new file mode 100644 index 0000000..8278194 --- /dev/null +++ b/drivers/interconnect/exynos/exynos.c @@ -0,0 +1,185 @@ +// 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>
+#define kbps_to_khz(x) ((x) / 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;+};
+static struct icc_node *exynos_icc_get_parent(struct device_node *np) +{
struct of_phandle_args args;int num, ret;num = of_count_phandle_with_args(np, "samsung,interconnect-parent","#interconnect-cells");if (num != 1)return NULL; /* parent nodes are optional */ret = of_parse_phandle_with_args(np, "samsung,interconnect-parent","#interconnect-cells", 0, &args);if (ret < 0)return ERR_PTR(ret);of_node_put(args.np);return of_icc_get_from_provider(&args);+}
+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 = kbps_to_khz(max(src->avg_bw, src->peak_bw));s32 dst_freq = kbps_to_khz(max(dst->avg_bw, dst->peak_bw));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\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\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;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);icc_provider_del(&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;ret = icc_provider_add(provider);if (ret < 0)return ret;icc_node = icc_node_create(pdev->id);if (IS_ERR(icc_node)) {ret = PTR_ERR(icc_node);goto err_prov_del;}priv->node = icc_node;icc_node->name = bus_dev->of_node->name;icc_node->data = priv;icc_node_add(icc_node, provider);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_node_del;}if (icc_parent_node) {ret = icc_link_create(icc_node, icc_parent_node->id);if (ret < 0)goto err_node_del;}/** Register a PM QoS request for the bus device for which also devfreq* functionality is registered.*/ret = dev_pm_qos_add_request(bus_dev, &priv->qos_req,DEV_PM_QOS_MIN_FREQUENCY, 0);if (ret < 0)goto err_link_destroy;return 0;+err_link_destroy:
if (icc_parent_node)icc_link_destroy(icc_node, icc_parent_node);+err_node_del:
icc_nodes_remove(provider);+err_prov_del:
icc_provider_del(provider);return ret;+}
+static struct platform_driver exynos_generic_icc_driver = {
.driver = {.name = "exynos-generic-icc",},.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");
2.7.4
Reviewed-by: Chanwoo Choi cw00.choi@samsung.com
As I commented, How about changing the compatible name 'exynos-icc' without 'generic'? The 'exynos-icc' doesn't have the any specific version of Exynos SoC, it think that it already contain the 'generic' meaning for Exynos SoC.