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://patchwork.kernel.org/patch/11458981/ The dt-binding document for this driver is required under Documentation/devicetree/binding/devfreq. 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. > >> 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
