diff options
Diffstat (limited to 'drivers/devfreq/event/rockchip-dfi.c')
| -rw-r--r-- | drivers/devfreq/event/rockchip-dfi.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/devfreq/event/rockchip-dfi.c b/drivers/devfreq/event/rockchip-dfi.c new file mode 100644 index 000000000..4dafdf231 --- /dev/null +++ b/drivers/devfreq/event/rockchip-dfi.c @@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd + * Author: Lin Huang <hl@rock-chips.com> + */ + +#include <linux/clk.h> +#include <linux/devfreq-event.h> +#include <linux/kernel.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/slab.h> +#include <linux/list.h> +#include <linux/of.h> + +#include <soc/rockchip/rk3399_grf.h> + +#define RK3399_DMC_NUM_CH 2 + +/* DDRMON_CTRL */ +#define DDRMON_CTRL 0x04 +#define CLR_DDRMON_CTRL (0x1f0000 << 0) +#define LPDDR4_EN (0x10001 << 4) +#define HARDWARE_EN (0x10001 << 3) +#define LPDDR3_EN (0x10001 << 2) +#define SOFTWARE_EN (0x10001 << 1) +#define SOFTWARE_DIS (0x10000 << 1) +#define TIME_CNT_EN (0x10001 << 0) + +#define DDRMON_CH0_COUNT_NUM 0x28 +#define DDRMON_CH0_DFI_ACCESS_NUM 0x2c +#define DDRMON_CH1_COUNT_NUM 0x3c +#define DDRMON_CH1_DFI_ACCESS_NUM 0x40 + +struct dmc_usage { + u32 access; + u32 total; +}; + +/* + * The dfi controller can monitor DDR load. It has an upper and lower threshold + * for the operating points. Whenever the usage leaves these bounds an event is + * generated to indicate the DDR frequency should be changed. + */ +struct rockchip_dfi { + struct devfreq_event_dev *edev; + struct devfreq_event_desc *desc; + struct dmc_usage ch_usage[RK3399_DMC_NUM_CH]; + struct device *dev; + void __iomem *regs; + struct regmap *regmap_pmu; + struct clk *clk; +}; + +static void rockchip_dfi_start_hardware_counter(struct devfreq_event_dev *edev) +{ + struct rockchip_dfi *info = devfreq_event_get_drvdata(edev); + void __iomem *dfi_regs = info->regs; + u32 val; + u32 ddr_type; + + /* get ddr type */ + regmap_read(info->regmap_pmu, RK3399_PMUGRF_OS_REG2, &val); + ddr_type = (val >> RK3399_PMUGRF_DDRTYPE_SHIFT) & + RK3399_PMUGRF_DDRTYPE_MASK; + + /* clear DDRMON_CTRL setting */ + writel_relaxed(CLR_DDRMON_CTRL, dfi_regs + DDRMON_CTRL); + + /* set ddr type to dfi */ + if (ddr_type == RK3399_PMUGRF_DDRTYPE_LPDDR3) + writel_relaxed(LPDDR3_EN, dfi_regs + DDRMON_CTRL); + else if (ddr_type == RK3399_PMUGRF_DDRTYPE_LPDDR4) + writel_relaxed(LPDDR4_EN, dfi_regs + DDRMON_CTRL); + + /* enable count, use software mode */ + writel_relaxed(SOFTWARE_EN, dfi_regs + DDRMON_CTRL); +} + +static void rockchip_dfi_stop_hardware_counter(struct devfreq_event_dev *edev) +{ + struct rockchip_dfi *info = devfreq_event_get_drvdata(edev); + void __iomem *dfi_regs = info->regs; + + writel_relaxed(SOFTWARE_DIS, dfi_regs + DDRMON_CTRL); +} + +static int rockchip_dfi_get_busier_ch(struct devfreq_event_dev *edev) +{ + struct rockchip_dfi *info = devfreq_event_get_drvdata(edev); + u32 tmp, max = 0; + u32 i, busier_ch = 0; + void __iomem *dfi_regs = info->regs; + + rockchip_dfi_stop_hardware_counter(edev); + + /* Find out which channel is busier */ + for (i = 0; i < RK3399_DMC_NUM_CH; i++) { + info->ch_usage[i].access = readl_relaxed(dfi_regs + + DDRMON_CH0_DFI_ACCESS_NUM + i * 20) * 4; + info->ch_usage[i].total = readl_relaxed(dfi_regs + + DDRMON_CH0_COUNT_NUM + i * 20); + tmp = info->ch_usage[i].access; + if (tmp > max) { + busier_ch = i; + max = tmp; + } + } + rockchip_dfi_start_hardware_counter(edev); + + return busier_ch; +} + +static int rockchip_dfi_disable(struct devfreq_event_dev *edev) +{ + struct rockchip_dfi *info = devfreq_event_get_drvdata(edev); + + rockchip_dfi_stop_hardware_counter(edev); + clk_disable_unprepare(info->clk); + + return 0; +} + +static int rockchip_dfi_enable(struct devfreq_event_dev *edev) +{ + struct rockchip_dfi *info = devfreq_event_get_drvdata(edev); + int ret; + + ret = clk_prepare_enable(info->clk); + if (ret) { + dev_err(&edev->dev, "failed to enable dfi clk: %d\n", ret); + return ret; + } + + rockchip_dfi_start_hardware_counter(edev); + return 0; +} + +static int rockchip_dfi_set_event(struct devfreq_event_dev *edev) +{ + return 0; +} + +static int rockchip_dfi_get_event(struct devfreq_event_dev *edev, + struct devfreq_event_data *edata) +{ + struct rockchip_dfi *info = devfreq_event_get_drvdata(edev); + int busier_ch; + + busier_ch = rockchip_dfi_get_busier_ch(edev); + + edata->load_count = info->ch_usage[busier_ch].access; + edata->total_count = info->ch_usage[busier_ch].total; + + return 0; +} + +static const struct devfreq_event_ops rockchip_dfi_ops = { + .disable = rockchip_dfi_disable, + .enable = rockchip_dfi_enable, + .get_event = rockchip_dfi_get_event, + .set_event = rockchip_dfi_set_event, +}; + +static const struct of_device_id rockchip_dfi_id_match[] = { + { .compatible = "rockchip,rk3399-dfi" }, + { }, +}; +MODULE_DEVICE_TABLE(of, rockchip_dfi_id_match); + +static int rockchip_dfi_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rockchip_dfi *data; + struct devfreq_event_desc *desc; + struct device_node *np = pdev->dev.of_node, *node; + + data = devm_kzalloc(dev, sizeof(struct rockchip_dfi), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(data->regs)) + return PTR_ERR(data->regs); + + data->clk = devm_clk_get(dev, "pclk_ddr_mon"); + if (IS_ERR(data->clk)) { + dev_err(dev, "Cannot get the clk dmc_clk\n"); + return PTR_ERR(data->clk); + } + + node = of_parse_phandle(np, "rockchip,pmu", 0); + if (!node) + return dev_err_probe(&pdev->dev, -ENODEV, "Can't find pmu_grf registers\n"); + + data->regmap_pmu = syscon_node_to_regmap(node); + of_node_put(node); + if (IS_ERR(data->regmap_pmu)) + return PTR_ERR(data->regmap_pmu); + + data->dev = dev; + + desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL); + if (!desc) + return -ENOMEM; + + desc->ops = &rockchip_dfi_ops; + desc->driver_data = data; + desc->name = np->name; + data->desc = desc; + + data->edev = devm_devfreq_event_add_edev(&pdev->dev, desc); + if (IS_ERR(data->edev)) { + dev_err(&pdev->dev, + "failed to add devfreq-event device\n"); + return PTR_ERR(data->edev); + } + + platform_set_drvdata(pdev, data); + + return 0; +} + +static struct platform_driver rockchip_dfi_driver = { + .probe = rockchip_dfi_probe, + .driver = { + .name = "rockchip-dfi", + .of_match_table = rockchip_dfi_id_match, + }, +}; +module_platform_driver(rockchip_dfi_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Lin Huang <hl@rock-chips.com>"); +MODULE_DESCRIPTION("Rockchip DFI driver"); |