Hi Artur, On 12/3/19 2:05 AM, Artur Świgoń wrote: > Hi Chanwoo, > > On Wed, 2019-09-25 at 16:03 +0900, Chanwoo Choi wrote: >> Hi, >> >> I need the time to dig the ICC framework >> to understand them detailed. After that, I'll review this. > > Any updates on this topic? I'm sorry for delaying the review of this topic related to icc. The review and merge of devfreq pm-qos feature will be finished over soon. Because this series depends on the devfreq pm-qos feature I'll dig into ICC related patches for exynos and imx[1]. [1] https://lore.kernel.org/linux-arm-kernel/008f2fa973b23fc716d678c5bd35af54@xxxxxxxx/T/ [PATCH RFC v6 0/9] interconnect: Add imx support via devfreq > > Regardless of the purpose of this RFC, I think patches 01-04 > are still beneficial to devfreq. I can rebase and post them > as a separate series if you wish. Yes. please split out patch1-4 from this series and send them based on linux-next.git separately. > >> Basically, I agree this approach. But, I'm wondering >> the existing binding method between 'bus_leftbus' and 'bus_dmc'. >> From before, I thought that devfreq framework need to >> enhance the binding method between parent devfreq device >> and passive devfreq device instead of 'devfreq' property. >> >> On this patch, use the same binding way between >> 'bus_leftbus' and 'bus_dmc' with 'parent' property >> as following: >> >> +++ b/arch/arm/boot/dts/exynos4412-odroid-common.dtsi >> @@ -106,6 +106,7 @@ >> &bus_leftbus { >> devfreq-events = <&ppmu_leftbus_3>, <&ppmu_rightbus_3>; >> vdd-supply = <&buck3_reg>; >> + parent = <&bus_dmc>; >> status = "okay"; >> }; >> >> I'm not sure about continuing to use this method for new feature. >> If possible, hope to replace the existing binding style >> with new method like of_graph. Actually, I don't know the correct method. >> >> >> On 19. 9. 19. 오후 11:22, Artur Świgoń wrote: >>> From: Artur Świgoń <a.swigon@xxxxxxxxxxxxxxxxxxx> >>> >>> This patch adds interconnect functionality to the exynos-bus devfreq >>> driver. >>> >>> The SoC topology is a graph (or, more specifically, a tree) and most of >>> its edges are taken from the devfreq parent-child hierarchy (cf. >>> Documentation/devicetree/bindings/devfreq/exynos-bus.txt). Due to >>> unspecified relative probing order, -EPROBE_DEFER may be propagated to >>> guarantee that a child is probed before its parent. >>> >>> 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 at >>> runtime, in probing order (subject to the above-mentioned exception >>> regarding relative order). 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@xxxxxxxxxxxxxxxxxxx> >>> --- >>> drivers/devfreq/exynos-bus.c | 153 +++++++++++++++++++++++++++++++++++ >>> 1 file changed, 153 insertions(+) >>> >>> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c >>> index 8d44810cac69..e0232202720d 100644 >>> --- a/drivers/devfreq/exynos-bus.c >>> +++ b/drivers/devfreq/exynos-bus.c >>> @@ -14,14 +14,19 @@ >>> #include <linux/devfreq-event.h> >>> #include <linux/device.h> >>> #include <linux/export.h> >>> +#include <linux/idr.h> >>> +#include <linux/interconnect-provider.h> >>> #include <linux/module.h> >>> #include <linux/of.h> >>> #include <linux/pm_opp.h> >>> +#include <linux/pm_qos.h> >>> #include <linux/platform_device.h> >>> #include <linux/regulator/consumer.h> >>> >>> #define DEFAULT_SATURATION_RATIO 40 >>> >>> +#define icc_units_to_khz(x) ((x) / 8) >>> + >>> struct exynos_bus { >>> struct device *dev; >>> >>> @@ -35,6 +40,12 @@ struct exynos_bus { >>> struct opp_table *opp_table; >>> struct clk *clk; >>> unsigned int ratio; >>> + >>> + /* One provider per bus, one node per provider */ >>> + struct icc_provider provider; >>> + struct icc_node *node; >>> + >>> + struct dev_pm_qos_request qos_req; >>> }; >>> >>> /* >>> @@ -59,6 +70,13 @@ exynos_bus_ops_edev(enable_edev); >>> exynos_bus_ops_edev(disable_edev); >>> exynos_bus_ops_edev(set_event); >>> >>> +static int exynos_bus_next_id(void) >>> +{ >>> + static DEFINE_IDA(exynos_bus_icc_ida); >>> + >>> + return ida_alloc(&exynos_bus_icc_ida, GFP_KERNEL); >>> +} >>> + >>> static int exynos_bus_get_event(struct exynos_bus *bus, >>> struct devfreq_event_data *edata) >>> { >>> @@ -171,6 +189,38 @@ static void exynos_bus_passive_exit(struct device *dev) >>> clk_disable_unprepare(bus->clk); >>> } >>> >>> +static int exynos_bus_icc_set(struct icc_node *src, struct icc_node *dst) >>> +{ >>> + struct exynos_bus *src_bus = src->data, *dst_bus = dst->data; >>> + s32 src_freq = icc_units_to_khz(src->avg_bw); >>> + s32 dst_freq = icc_units_to_khz(dst->avg_bw); >>> + >>> + dev_pm_qos_update_request(&src_bus->qos_req, src_freq); >>> + dev_pm_qos_update_request(&dst_bus->qos_req, dst_freq); >>> + >>> + return 0; >>> +} >>> + >>> +static int exynos_bus_icc_aggregate(struct icc_node *node, u32 tag, u32 avg_bw, >>> + u32 peak_bw, u32 *agg_avg, u32 *agg_peak) >>> +{ >>> + *agg_avg += avg_bw; >>> + *agg_peak = max(*agg_peak, peak_bw); >>> + >>> + return 0; >>> +} >>> + >>> +static struct icc_node *exynos_bus_icc_xlate(struct of_phandle_args *spec, >>> + void *data) >>> +{ >>> + struct exynos_bus *bus = data; >>> + >>> + if (spec->np != bus->dev->of_node) >>> + return ERR_PTR(-EINVAL); >>> + >>> + return bus->node; >>> +} >>> + >>> static int exynos_bus_parent_parse_of(struct device_node *np, >>> struct exynos_bus *bus) >>> { >>> @@ -366,6 +416,101 @@ static int exynos_bus_profile_init_passive(struct exynos_bus *bus, >>> return 0; >>> } >>> >>> +static int exynos_bus_icc_connect(struct exynos_bus *bus) >>> +{ >>> + struct device_node *np = bus->dev->of_node; >>> + struct devfreq *parent_devfreq; >>> + struct icc_node *parent_node = NULL; >>> + struct of_phandle_args args; >>> + int ret = 0; >>> + >>> + parent_devfreq = devfreq_get_devfreq_by_phandle(bus->dev, 0); >>> + if (!IS_ERR(parent_devfreq)) { >>> + struct exynos_bus *parent_bus; >>> + >>> + parent_bus = dev_get_drvdata(parent_devfreq->dev.parent); >>> + parent_node = parent_bus->node; >>> + } else { >>> + /* Look for parent in DT */ >>> + int num = of_count_phandle_with_args(np, "parent", >>> + "#interconnect-cells"); >>> + if (num != 1) >>> + goto out; /* 'parent' is optional */ >>> + >>> + ret = of_parse_phandle_with_args(np, "parent", >>> + "#interconnect-cells", >>> + 0, &args); >>> + if (ret < 0) >>> + goto out; >>> + >>> + of_node_put(args.np); >>> + >>> + parent_node = of_icc_get_from_provider(&args); >>> + if (IS_ERR(parent_node)) { >>> + /* May be -EPROBE_DEFER */ >>> + ret = PTR_ERR(parent_node); >>> + goto out; >>> + } >>> + } >> >> >> >>> + >>> + ret = icc_link_create(bus->node, parent_node->id); >>> + >>> +out: >>> + return ret; >>> +} >>> + >>> +static int exynos_bus_icc_init(struct exynos_bus *bus) >>> +{ >>> + struct device *dev = bus->dev; >>> + struct icc_provider *provider = &bus->provider; >>> + struct icc_node *node; >>> + int id, ret; >>> + >>> + /* Initialize the interconnect provider */ >>> + provider->set = exynos_bus_icc_set; >>> + provider->aggregate = exynos_bus_icc_aggregate; >>> + provider->xlate = exynos_bus_icc_xlate; >>> + provider->dev = dev; >>> + provider->data = bus; >>> + >>> + ret = icc_provider_add(provider); >>> + if (ret < 0) >>> + goto out; >>> + >>> + ret = id = exynos_bus_next_id(); >>> + if (ret < 0) >>> + goto err_node; >>> + >>> + node = icc_node_create(id); >>> + if (IS_ERR(node)) { >>> + ret = PTR_ERR(node); >>> + goto err_node; >>> + } >>> + >>> + bus->node = node; >>> + node->name = dev->of_node->name; >>> + node->data = bus; >>> + icc_node_add(node, provider); >>> + >>> + ret = exynos_bus_icc_connect(bus); >>> + if (ret < 0) >>> + goto err_connect; >>> + >>> + ret = dev_pm_qos_add_request(bus->devfreq->dev.parent, &bus->qos_req, >>> + DEV_PM_QOS_MIN_FREQUENCY, 0); >>> + >>> +out: >>> + return ret; >>> + >>> +err_connect: >>> + icc_node_del(node); >>> + icc_node_destroy(id); >>> +err_node: >>> + icc_provider_del(provider); >>> + >>> + return ret; >>> +} >>> + >>> static int exynos_bus_probe(struct platform_device *pdev) >>> { >>> struct device *dev = &pdev->dev; >>> @@ -415,6 +560,14 @@ static int exynos_bus_probe(struct platform_device *pdev) >>> if (ret < 0) >>> goto err; >>> >>> + /* >>> + * Initialize interconnect provider. A return value of -ENOTSUPP means >>> + * that CONFIG_INTERCONNECT is disabled. >>> + */ >>> + ret = exynos_bus_icc_init(bus); >>> + if (ret < 0 && ret != -ENOTSUPP) >>> + goto err; >>> + >>> max_state = bus->devfreq->profile->max_state; >>> min_freq = (bus->devfreq->profile->freq_table[0] / 1000); >>> max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000); >>> >> > > Best regards, > -- Best Regards, Chanwoo Choi Samsung Electronics
