--- /dev/null
+/*
+ * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
+ * Author: Lin Huang <hl@rock-chips.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#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>
+
+#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
+
+/* pmu grf */
+#define PMUGRF_OS_REG2 0x308
+#define DDRTYPE_SHIFT 13
+#define DDRTYPE_MASK 7
+
+enum {
+ DDR3 = 3,
+ LPDDR3 = 6,
+ LPDDR4 = 7,
+ UNUSED = 0xFF
+};
+
+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, PMUGRF_OS_REG2, &val);
+ ddr_type = (val >> DDRTYPE_SHIFT) & DDRTYPE_MASK;
+
+ /* clear DDRMON_CTRL setting */
+ writel_relaxed(CLR_DDRMON_CTRL, dfi_regs + DDRMON_CTRL);
+
+ /* set ddr type to dfi */
+ if (ddr_type == LPDDR3)
+ writel_relaxed(LPDDR3_EN, dfi_regs + DDRMON_CTRL);
+ else if (ddr_type == 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" },
+ { },
+};
+
+static int rockchip_dfi_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct rockchip_dfi *data;
+ struct resource *res;
+ 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;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ data->regs = devm_ioremap_resource(&pdev->dev, res);
+ 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);
+ };
+
+ /* try to find the optional reference to the pmu syscon */
+ node = of_parse_phandle(np, "rockchip,pmu", 0);
+ if (node) {
+ data->regmap_pmu = syscon_node_to_regmap(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");
projects / firefly-linux-kernel-4.4.55.git / commitdiff