diff options
Diffstat (limited to 'drivers/devfreq/imx-bus.c')
| -rw-r--r-- | drivers/devfreq/imx-bus.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/drivers/devfreq/imx-bus.c b/drivers/devfreq/imx-bus.c new file mode 100644 index 000000000000..4f38455ad742 --- /dev/null +++ b/drivers/devfreq/imx-bus.c @@ -0,0 +1,179 @@ +// 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 platform_device *icc_pdev; +}; + +static int imx_bus_target(struct device *dev, + unsigned long *freq, u32 flags) +{ + struct dev_pm_opp *new_opp; + 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; + } + dev_pm_opp_put(new_opp); + + return dev_pm_opp_set_rate(dev, *freq); +} + +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) +{ + struct imx_bus *priv = dev_get_drvdata(dev); + + dev_pm_opp_of_remove_table(dev); + platform_device_unregister(priv->icc_pdev); +} + +/* imx_bus_init_icc() - register matching icc provider if required */ +static int imx_bus_init_icc(struct device *dev) +{ + struct imx_bus *priv = dev_get_drvdata(dev); + const char *icc_driver_name; + + if (!of_get_property(dev->of_node, "#interconnect-cells", 0)) + return 0; + if (!IS_ENABLED(CONFIG_INTERCONNECT_IMX)) { + dev_warn(dev, "imx interconnect drivers disabled\n"); + return 0; + } + + icc_driver_name = of_device_get_match_data(dev); + if (!icc_driver_name) { + dev_err(dev, "unknown interconnect driver\n"); + return 0; + } + + priv->icc_pdev = platform_device_register_data( + dev, icc_driver_name, -1, NULL, 0); + if (IS_ERR(priv->icc_pdev)) { + dev_err(dev, "failed to register icc provider %s: %ld\n", + icc_driver_name, PTR_ERR(priv->icc_pdev)); + return PTR_ERR(priv->icc_pdev); + } + + return 0; +} + +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 explicitly enable. + * + * 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; + } + + ret = imx_bus_init_icc(dev); + if (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,imx8mq-noc", .data = "imx8mq-interconnect", }, + { .compatible = "fsl,imx8mm-noc", .data = "imx8mm-interconnect", }, + { .compatible = "fsl,imx8mn-noc", .data = "imx8mn-interconnect", }, + { .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@nxp.com>"); +MODULE_LICENSE("GPL v2"); |