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linux/drivers/interconnect/samsung/exynos.c

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interconnect: Add generic interconnect driver for Exynos SoCs 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 described by specifying in the 'interconnects' property the interconnect consumer path for each interconnect provider DT node. 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 hard coded 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. The samsung,data-clk-ratio DT property is used to specify the ratio of the interconect bandwidth to the minimum data clock frequency for each bus. Due to unspecified relative probing order, -EPROBE_DEFER may be propagated to ensure that the parent is probed before its children. Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Artur Świgoń <a.swigon@samsung.com> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Link: https://lore.kernel.org/r/20201112140931.31139-3-s.nawrocki@samsung.com Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
2020-11-12 15:09:28 +01:00
// 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);
interconnect: exynos: fix registration race The current interconnect provider registration interface is inherently racy as nodes are not added until the after adding the provider. This can specifically cause racing DT lookups to trigger a NULL-pointer deference when either a NULL pointer or not fully initialised node is returned from exynos_generic_icc_xlate(). Switch to using the new API where the provider is not registered until after it has been fully initialised. Fixes: 2f95b9d5cf0b ("interconnect: Add generic interconnect driver for Exynos SoCs") Cc: stable@vger.kernel.org # 5.11 Cc: Sylwester Nawrocki <s.nawrocki@samsung.com> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20230306075651.2449-16-johan+linaro@kernel.org Signed-off-by: Georgi Djakov <djakov@kernel.org>
2023-03-06 08:56:43 +01:00
icc_provider_deregister(&priv->provider);
interconnect: Add generic interconnect driver for Exynos SoCs 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 described by specifying in the 'interconnects' property the interconnect consumer path for each interconnect provider DT node. 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 hard coded 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. The samsung,data-clk-ratio DT property is used to specify the ratio of the interconect bandwidth to the minimum data clock frequency for each bus. Due to unspecified relative probing order, -EPROBE_DEFER may be propagated to ensure that the parent is probed before its children. Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Artur Świgoń <a.swigon@samsung.com> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Link: https://lore.kernel.org/r/20201112140931.31139-3-s.nawrocki@samsung.com Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
2020-11-12 15:09:28 +01:00
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;
interconnect: exynos: fix registration race The current interconnect provider registration interface is inherently racy as nodes are not added until the after adding the provider. This can specifically cause racing DT lookups to trigger a NULL-pointer deference when either a NULL pointer or not fully initialised node is returned from exynos_generic_icc_xlate(). Switch to using the new API where the provider is not registered until after it has been fully initialised. Fixes: 2f95b9d5cf0b ("interconnect: Add generic interconnect driver for Exynos SoCs") Cc: stable@vger.kernel.org # 5.11 Cc: Sylwester Nawrocki <s.nawrocki@samsung.com> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20230306075651.2449-16-johan+linaro@kernel.org Signed-off-by: Georgi Djakov <djakov@kernel.org>
2023-03-06 08:56:43 +01:00
icc_provider_init(provider);
interconnect: Add generic interconnect driver for Exynos SoCs 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 described by specifying in the 'interconnects' property the interconnect consumer path for each interconnect provider DT node. 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 hard coded 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. The samsung,data-clk-ratio DT property is used to specify the ratio of the interconect bandwidth to the minimum data clock frequency for each bus. Due to unspecified relative probing order, -EPROBE_DEFER may be propagated to ensure that the parent is probed before its children. Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Artur Świgoń <a.swigon@samsung.com> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Link: https://lore.kernel.org/r/20201112140931.31139-3-s.nawrocki@samsung.com Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
2020-11-12 15:09:28 +01:00
icc_node = icc_node_create(pdev->id);
interconnect: exynos: fix registration race The current interconnect provider registration interface is inherently racy as nodes are not added until the after adding the provider. This can specifically cause racing DT lookups to trigger a NULL-pointer deference when either a NULL pointer or not fully initialised node is returned from exynos_generic_icc_xlate(). Switch to using the new API where the provider is not registered until after it has been fully initialised. Fixes: 2f95b9d5cf0b ("interconnect: Add generic interconnect driver for Exynos SoCs") Cc: stable@vger.kernel.org # 5.11 Cc: Sylwester Nawrocki <s.nawrocki@samsung.com> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20230306075651.2449-16-johan+linaro@kernel.org Signed-off-by: Georgi Djakov <djakov@kernel.org>
2023-03-06 08:56:43 +01:00
if (IS_ERR(icc_node))
return PTR_ERR(icc_node);
interconnect: Add generic interconnect driver for Exynos SoCs 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 described by specifying in the 'interconnects' property the interconnect consumer path for each interconnect provider DT node. 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 hard coded 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. The samsung,data-clk-ratio DT property is used to specify the ratio of the interconect bandwidth to the minimum data clock frequency for each bus. Due to unspecified relative probing order, -EPROBE_DEFER may be propagated to ensure that the parent is probed before its children. Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Artur Świgoń <a.swigon@samsung.com> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Link: https://lore.kernel.org/r/20201112140931.31139-3-s.nawrocki@samsung.com Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
2020-11-12 15:09:28 +01:00
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;
interconnect: exynos: fix node leak in probe PM QoS error path Make sure to add the newly allocated interconnect node to the provider before adding the PM QoS request so that the node is freed on errors. Fixes: 2f95b9d5cf0b ("interconnect: Add generic interconnect driver for Exynos SoCs") Cc: stable@vger.kernel.org # 5.11 Cc: Sylwester Nawrocki <s.nawrocki@samsung.com> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20230306075651.2449-15-johan+linaro@kernel.org Signed-off-by: Georgi Djakov <djakov@kernel.org>
2023-03-06 08:56:42 +01:00
icc_node->data = priv;
icc_node_add(icc_node, provider);
interconnect: Add generic interconnect driver for Exynos SoCs 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 described by specifying in the 'interconnects' property the interconnect consumer path for each interconnect provider DT node. 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 hard coded 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. The samsung,data-clk-ratio DT property is used to specify the ratio of the interconect bandwidth to the minimum data clock frequency for each bus. Due to unspecified relative probing order, -EPROBE_DEFER may be propagated to ensure that the parent is probed before its children. Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Artur Świgoń <a.swigon@samsung.com> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Link: https://lore.kernel.org/r/20201112140931.31139-3-s.nawrocki@samsung.com Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
2020-11-12 15:09:28 +01:00
/*
* 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;
}
interconnect: exynos: fix registration race The current interconnect provider registration interface is inherently racy as nodes are not added until the after adding the provider. This can specifically cause racing DT lookups to trigger a NULL-pointer deference when either a NULL pointer or not fully initialised node is returned from exynos_generic_icc_xlate(). Switch to using the new API where the provider is not registered until after it has been fully initialised. Fixes: 2f95b9d5cf0b ("interconnect: Add generic interconnect driver for Exynos SoCs") Cc: stable@vger.kernel.org # 5.11 Cc: Sylwester Nawrocki <s.nawrocki@samsung.com> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20230306075651.2449-16-johan+linaro@kernel.org Signed-off-by: Georgi Djakov <djakov@kernel.org>
2023-03-06 08:56:43 +01:00
ret = icc_provider_register(provider);
if (ret < 0)
goto err_pmqos_del;
interconnect: Add generic interconnect driver for Exynos SoCs 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 described by specifying in the 'interconnects' property the interconnect consumer path for each interconnect provider DT node. 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 hard coded 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. The samsung,data-clk-ratio DT property is used to specify the ratio of the interconect bandwidth to the minimum data clock frequency for each bus. Due to unspecified relative probing order, -EPROBE_DEFER may be propagated to ensure that the parent is probed before its children. Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Artur Świgoń <a.swigon@samsung.com> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Link: https://lore.kernel.org/r/20201112140931.31139-3-s.nawrocki@samsung.com Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
2020-11-12 15:09:28 +01:00
return 0;
err_pmqos_del:
dev_pm_qos_remove_request(&priv->qos_req);
err_node_del:
icc_nodes_remove(provider);
interconnect: exynos: fix registration race The current interconnect provider registration interface is inherently racy as nodes are not added until the after adding the provider. This can specifically cause racing DT lookups to trigger a NULL-pointer deference when either a NULL pointer or not fully initialised node is returned from exynos_generic_icc_xlate(). Switch to using the new API where the provider is not registered until after it has been fully initialised. Fixes: 2f95b9d5cf0b ("interconnect: Add generic interconnect driver for Exynos SoCs") Cc: stable@vger.kernel.org # 5.11 Cc: Sylwester Nawrocki <s.nawrocki@samsung.com> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Link: https://lore.kernel.org/r/20230306075651.2449-16-johan+linaro@kernel.org Signed-off-by: Georgi Djakov <djakov@kernel.org>
2023-03-06 08:56:43 +01:00
interconnect: Add generic interconnect driver for Exynos SoCs 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 described by specifying in the 'interconnects' property the interconnect consumer path for each interconnect provider DT node. 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 hard coded 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. The samsung,data-clk-ratio DT property is used to specify the ratio of the interconect bandwidth to the minimum data clock frequency for each bus. Due to unspecified relative probing order, -EPROBE_DEFER may be propagated to ensure that the parent is probed before its children. Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Artur Świgoń <a.swigon@samsung.com> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Link: https://lore.kernel.org/r/20201112140931.31139-3-s.nawrocki@samsung.com Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
2020-11-12 15:09:28 +01:00
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");
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