On 4/2/20 6:53 PM, Leonard Crestez wrote: > On 2020-04-02 1:48 AM, Chanwoo Choi wrote: >> On 4/1/20 11:20 PM, Leonard Crestez wrote: >>> On 2020-04-01 1:55 AM, Chanwoo Choi wrote: >>>> Hi, >>>> >>>> Looks good to me. I added the comments. >>>> But, it need to add the dt binding documentation for this device. >>> >>> DT bindings were included: >>> >>> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchwork.kernel.org%2Fpatch%2F11458981%2F&data=02%7C01%7Cleonard.crestez%40nxp.com%7C7381d117a4d1468cd2c608d7d68ecfac%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637213781167514099&sdata=Qu8x14cXnuxlwOT2SlUOf%2FLgCVWbnJRKA4TBjMIWQeA%3D&reserved=0 >> >> The dt-binding document for this driver is required under >> Documentation/devicetree/binding/devfreq. > > Bindings for imx8m-ddrc were at one point posted for > devicetree/bindings/devfreq but Rob Herring suggested to move them under > "memory-controller" instead and I expect same logic makes sense here. > Link to previous discussion: > > https://patchwork.kernel.org/patch/11221919/ > > DT bindings should try to describe "hardware" rather than "drivers" and > an "interconnect" is a class of hardware while "devfreq" isn't. > > Not only that but the main noc has properties parsed by interconnect driver. OK. Thanks for reply. > >> It is difficult to catch where is the dt-binding document >> for this driver for who don't know the detailed history >> of this driver. I don't said that add the duplicate documentation >> But, at least the some document have to point out the reference. > > What I usually do to find information about a device is grep for the > compat string in the entire tree. > >>>> The old email of Artur Świgoń is not used. On next time, >>>> use following the new email address Because when I reply the mail, >>>> always show the fail message from thunderbird due to the Artur's old email. >>>> <a.swigon@xxxxxxxxxxxxxxxxxxx> -> <a.swigon@xxxxxxxxxxx> >>> >>> Yeah, I received multiple bounces because of this. >>> >>>> On 3/26/20 11:16 AM, Leonard Crestez wrote: >>>>> Add initial support for dynamic frequency switching on pieces of the imx >>>>> interconnect fabric. >>>>> >>>>> All this driver does is set a clk rate based on an opp table, it does >>>>> not map register areas. >>>>> >>>>> Signed-off-by: Leonard Crestez <leonard.crestez@xxxxxxx> >>>>> --- >>>>> drivers/devfreq/Kconfig | 9 +++ >>>>> drivers/devfreq/Makefile | 1 + >>>>> drivers/devfreq/imx-bus.c | 142 ++++++++++++++++++++++++++++++++++++++ >>>>> 3 files changed, 152 insertions(+) >>>>> create mode 100644 drivers/devfreq/imx-bus.c >>>>> >>>>> diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig >>>>> index 0b1df12e0f21..44d26192ddc4 100644 >>>>> --- a/drivers/devfreq/Kconfig >>>>> +++ b/drivers/devfreq/Kconfig >>>>> @@ -99,10 +99,19 @@ config ARM_IMX8M_DDRC_DEVFREQ >>>>> select DEVFREQ_GOV_USERSPACE >>>>> help >>>>> This adds the DEVFREQ driver for the i.MX8M DDR Controller. It allows >>>>> adjusting DRAM frequency. >>>>> >>>>> +config ARM_IMX_BUS_DEVFREQ >>>>> + tristate "i.MX Generic Bus DEVFREQ Driver" >>>>> + depends on ARCH_MXC || COMPILE_TEST >>>>> + select DEVFREQ_GOV_PASSIVE >>>>> + select DEVFREQ_GOV_USERSPACE >>>> >>>> Maybe, you would update it by using passive governor? >>>> But, in this version, it doesn't handle the any passive governor. >>> >>> dropped >>> >>>>> + help >>>>> + This adds the generic DEVFREQ driver for i.MX interconnects. It >>>>> + allows adjusting NIC/NOC frequency. >>>>> + >>>>> config ARM_TEGRA_DEVFREQ >>>>> tristate "NVIDIA Tegra30/114/124/210 DEVFREQ Driver" >>>>> depends on ARCH_TEGRA_3x_SOC || ARCH_TEGRA_114_SOC || \ >>>>> ARCH_TEGRA_132_SOC || ARCH_TEGRA_124_SOC || \ >>>>> ARCH_TEGRA_210_SOC || \ >>>>> diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile >>>>> index 3eb4d5e6635c..3ca1ad0ecb97 100644 >>>>> --- a/drivers/devfreq/Makefile >>>>> +++ b/drivers/devfreq/Makefile >>>>> @@ -7,10 +7,11 @@ obj-$(CONFIG_DEVFREQ_GOV_POWERSAVE) += governor_powersave.o >>>>> obj-$(CONFIG_DEVFREQ_GOV_USERSPACE) += governor_userspace.o >>>>> obj-$(CONFIG_DEVFREQ_GOV_PASSIVE) += governor_passive.o >>>>> >>>>> # DEVFREQ Drivers >>>>> obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ) += exynos-bus.o >>>>> +obj-$(CONFIG_ARM_IMX_BUS_DEVFREQ) += imx-bus.o >>>> >>>> The ARM_IMX_BUS_DEVFREQ config is under ARM_IMX8M_DDRC_DEVFREQ >>>> and imx-bus.o is over imx8m-ddrc.o. Need to edit the sequence. >>> >>> Reordered kconfig to match. 8M_DDRC sorts before _BUS alphabetically but >>> it's pettier this way, and matches tegra. >>> >>>>> obj-$(CONFIG_ARM_IMX8M_DDRC_DEVFREQ) += imx8m-ddrc.o >>>>> obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ) += rk3399_dmc.o >>>>> obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra30-devfreq.o >>>>> obj-$(CONFIG_ARM_TEGRA20_DEVFREQ) += tegra20-devfreq.o >>>>> >>>>> diff --git a/drivers/devfreq/imx-bus.c b/drivers/devfreq/imx-bus.c >>>>> new file mode 100644 >>>>> index 000000000000..285e0f1ae6b1 >>>>> --- /dev/null >>>>> +++ b/drivers/devfreq/imx-bus.c >>>>> @@ -0,0 +1,142 @@ >>>>> +// SPDX-License-Identifier: GPL-2.0 >>>>> +/* >>>>> + * Copyright 2019 NXP >>>>> + */ >>>>> + >>>>> +#include <linux/clk.h> >>>>> +#include <linux/devfreq.h> >>>>> +#include <linux/device.h> >>>>> +#include <linux/module.h> >>>>> +#include <linux/of_device.h> >>>>> +#include <linux/pm_opp.h> >>>>> +#include <linux/platform_device.h> >>>>> +#include <linux/slab.h> >>>>> + >>>>> +struct imx_bus { >>>>> + struct devfreq_dev_profile profile; >>>>> + struct devfreq *devfreq; >>>>> + struct clk *clk; >>>>> + struct devfreq_passive_data passive_data; >>>> >>>> This patch doesn't touch the passive_data. >>> >>> dropped >>> >>>>> +}; >>>>> + >>>>> +static int imx_bus_target(struct device *dev, >>>>> + unsigned long *freq, u32 flags) >>>>> +{ >>>>> + struct imx_bus *priv = dev_get_drvdata(dev); >>>>> + struct dev_pm_opp *new_opp; >>>>> + unsigned long new_freq; >>>>> + int ret; >>>>> + >>>>> + new_opp = devfreq_recommended_opp(dev, freq, flags); >>>>> + if (IS_ERR(new_opp)) { >>>>> + ret = PTR_ERR(new_opp); >>>>> + dev_err(dev, "failed to get recommended opp: %d\n", ret); >>>>> + return ret; >>>>> + } >>>>> + new_freq = dev_pm_opp_get_freq(new_opp); >>>> >>>> It doesn't need. Because the new frequency is stored to 'freq' >>>> by calling devfreq_recommended_opp(). >>> >>> fixed >>> >>>>> + dev_pm_opp_put(new_opp); >>>>> + >>>>> + return clk_set_rate(priv->clk, new_freq); >>>> >>>> nitpick. you can use dev_pm_opp_set_rate(). But, I'm not forcing to use it. >>> >>> Switched to dev_pm_opp_set_rate. >>> >>> It might be interesting to add regulators control later, on some chips >>> the main NOC can run at different voltages. >>> >>>> >>>>> +} >>>>> + >>>>> +static int imx_bus_get_cur_freq(struct device *dev, unsigned long *freq) >>>>> +{ >>>>> + struct imx_bus *priv = dev_get_drvdata(dev); >>>>> + >>>>> + *freq = clk_get_rate(priv->clk); >>>>> + >>>>> + return 0; >>>>> +} >>>>> + >>>>> +static int imx_bus_get_dev_status(struct device *dev, >>>>> + struct devfreq_dev_status *stat) >>>>> +{ >>>>> + struct imx_bus *priv = dev_get_drvdata(dev); >>>>> + >>>>> + stat->busy_time = 0; >>>>> + stat->total_time = 0; >>>>> + stat->current_frequency = clk_get_rate(priv->clk); >>>>> + >>>>> + return 0; >>>>> +} >>>>> + >>>>> +static void imx_bus_exit(struct device *dev) >>>>> +{ >>>>> + dev_pm_opp_of_remove_table(dev); >>>>> +} >>>>> + >>>>> +static int imx_bus_probe(struct platform_device *pdev) >>>>> +{ >>>>> + struct device *dev = &pdev->dev; >>>>> + struct imx_bus *priv; >>>>> + const char *gov = DEVFREQ_GOV_USERSPACE; >>>>> + int ret; >>>>> + >>>>> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); >>>>> + if (!priv) >>>>> + return -ENOMEM; >>>>> + >>>>> + /* >>>>> + * Fetch the clock to adjust but don't explictly enable. >>>> >>>> Need to fix typo. >>>> s/explictly/explicitly >>> >>> fixed >>> >>>>> + * >>>>> + * For imx bus clock clk_set_rate is safe no matter if the clock is on >>>>> + * or off and some peripheral side-buses might be off unless enabled by >>>>> + * drivers for devices on those specific buses. >>>>> + * >>>>> + * Rate adjustment on a disabled bus clock just takes effect later. >>>>> + */ >>>>> + priv->clk = devm_clk_get(dev, NULL); >>>>> + if (IS_ERR(priv->clk)) { >>>>> + ret = PTR_ERR(priv->clk); >>>>> + dev_err(dev, "failed to fetch clk: %d\n", ret); >>>>> + return ret; >>>>> + } >>>>> + platform_set_drvdata(pdev, priv); >>>>> + >>>>> + ret = dev_pm_opp_of_add_table(dev); >>>>> + if (ret < 0) { >>>>> + dev_err(dev, "failed to get OPP table\n"); >>>>> + return ret; >>>>> + } >>>>> + >>>>> + priv->profile.polling_ms = 1000; >>>>> + priv->profile.target = imx_bus_target; >>>>> + priv->profile.get_dev_status = imx_bus_get_dev_status; >>>>> + priv->profile.exit = imx_bus_exit; >>>>> + priv->profile.get_cur_freq = imx_bus_get_cur_freq; >>>>> + priv->profile.initial_freq = clk_get_rate(priv->clk); >>>>> + >>>>> + priv->devfreq = devm_devfreq_add_device(dev, &priv->profile, >>>>> + gov, NULL); >>>>> + if (IS_ERR(priv->devfreq)) { >>>>> + ret = PTR_ERR(priv->devfreq); >>>>> + dev_err(dev, "failed to add devfreq device: %d\n", ret); >>>>> + goto err; >>>>> + } >>>>> + >>>>> + return 0; >>>>> + >>>>> +err: >>>>> + dev_pm_opp_of_remove_table(dev); >>>>> + return ret; >>>>> +} >>>>> + >>>>> +static const struct of_device_id imx_bus_of_match[] = { >>>>> + { .compatible = "fsl,imx8m-noc", }, >>>>> + { .compatible = "fsl,imx8m-nic", }, >>>>> + { /* sentinel */ }, >>>>> +}; >>>>> +MODULE_DEVICE_TABLE(of, imx_bus_of_match); >>>>> + >>>>> +static struct platform_driver imx_bus_platdrv = { >>>>> + .probe = imx_bus_probe, >>>>> + .driver = { >>>>> + .name = "imx-bus-devfreq", >>>>> + .of_match_table = of_match_ptr(imx_bus_of_match), >>>>> + }, >>>>> +}; >>>>> +module_platform_driver(imx_bus_platdrv); >>>>> + >>>>> +MODULE_DESCRIPTION("Generic i.MX bus frequency scaling driver"); >>>>> +MODULE_AUTHOR("Leonard Crestez <leonard.crestez@xxxxxxx>"); >>>>> +MODULE_LICENSE("GPL v2"); >>>>> >>>> >>>> >>> >>> >>> >>> >> >> > > > -- Best Regards, Chanwoo Choi Samsung Electronics
