[PATCH V7 03/13] soc: mediatek: add driver for dvfsrc support

[Henry Chen <henryc.chen@mediatek.com>]

Add dvfsrc driver for MT6873/MT8183/MT8192

Signed-off-by: Henry Chen <henryc.chen@mediatek.com>
---
 drivers/soc/mediatek/Kconfig            |  12 +
 drivers/soc/mediatek/Makefile           |   1 +
 drivers/soc/mediatek/mtk-dvfsrc.c       | 421 ++++++++++++++++++++++++++++++++
 include/linux/soc/mediatek/mtk_dvfsrc.h |  35 +++
 4 files changed, 469 insertions(+)
 create mode 100644 drivers/soc/mediatek/mtk-dvfsrc.c
 create mode 100644 include/linux/soc/mediatek/mtk_dvfsrc.h

diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
index fdd8bc0..693a0ff 100644
--- a/drivers/soc/mediatek/Kconfig
+++ b/drivers/soc/mediatek/Kconfig
@@ -26,6 +26,18 @@ config MTK_DEVAPC
 	  The violation information is logged for further analysis or
 	  countermeasures.
 
+config MTK_DVFSRC
+	tristate "MediaTek DVFSRC Support"
+	depends on ARCH_MEDIATEK
+	depends on MTK_SCPSYS
+	help
+	  Say yes here to add support for the MediaTek DVFSRC (dynamic voltage
+	  and frequency scaling resource collector) found
+	  on different MediaTek SoCs. The DVFSRC is a proprietary
+	  hardware which is used to collect all the requests from
+	  system and turn into the decision of minimum Vcore voltage
+	  and minimum DRAM frequency to fulfill those requests.
+
 config MTK_INFRACFG
 	bool "MediaTek INFRACFG Support"
 	select REGMAP
diff --git a/drivers/soc/mediatek/Makefile b/drivers/soc/mediatek/Makefile
index b6908db..4ead103 100644
--- a/drivers/soc/mediatek/Makefile
+++ b/drivers/soc/mediatek/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_MTK_CMDQ) += mtk-cmdq-helper.o
 obj-$(CONFIG_MTK_DEVAPC) += mtk-devapc.o
+obj-$(CONFIG_MTK_DVFSRC) += mtk-dvfsrc.o
 obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
 obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
 obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
diff --git a/drivers/soc/mediatek/mtk-dvfsrc.c b/drivers/soc/mediatek/mtk-dvfsrc.c
new file mode 100644
index 0000000..c0c6d91
--- /dev/null
+++ b/drivers/soc/mediatek/mtk-dvfsrc.c
@@ -0,0 +1,421 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 MediaTek Inc.
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/soc/mediatek/mtk_dvfsrc.h>
+#include <linux/soc/mediatek/mtk_sip_svc.h>
+
+#define DVFSRC_IDLE     0x00
+#define DVFSRC_GET_TARGET_LEVEL(x)  (((x) >> 0) & 0x0000ffff)
+#define DVFSRC_GET_CURRENT_LEVEL(x) (((x) >> 16) & 0x0000ffff)
+#define kbps_to_mbps(x) ((x) / 1000)
+
+#define POLL_TIMEOUT        1000
+#define STARTUP_TIME        1
+
+#define MTK_SIP_DVFSRC_INIT		0x00
+
+#define DVFSRC_OPP_DESC(_opp_table)	\
+{	\
+	.opps = _opp_table,	\
+	.num_opp = ARRAY_SIZE(_opp_table),	\
+}
+
+struct dvfsrc_opp {
+	u32 vcore_opp;
+	u32 dram_opp;
+};
+
+struct dvfsrc_opp_desc {
+	const struct dvfsrc_opp *opps;
+	u32 num_opp;
+};
+
+struct mtk_dvfsrc;
+struct dvfsrc_soc_data {
+	const int *regs;
+	const struct dvfsrc_opp_desc *opps_desc;
+	int (*get_target_level)(struct mtk_dvfsrc *dvfsrc);
+	int (*get_current_level)(struct mtk_dvfsrc *dvfsrc);
+	u32 (*get_vcore_level)(struct mtk_dvfsrc *dvfsrc);
+	u32 (*get_vcp_level)(struct mtk_dvfsrc *dvfsrc);
+	void (*set_dram_bw)(struct mtk_dvfsrc *dvfsrc, u64 bw);
+	void (*set_dram_peak_bw)(struct mtk_dvfsrc *dvfsrc, u64 bw);
+	void (*set_dram_hrtbw)(struct mtk_dvfsrc *dvfsrc, u64 bw);
+	void (*set_opp_level)(struct mtk_dvfsrc *dvfsrc, u32 level);
+	void (*set_vcore_level)(struct mtk_dvfsrc *dvfsrc, u32 level);
+	void (*set_vscp_level)(struct mtk_dvfsrc *dvfsrc, u32 level);
+	int (*wait_for_opp_level)(struct mtk_dvfsrc *dvfsrc, u32 level);
+	int (*wait_for_vcore_level)(struct mtk_dvfsrc *dvfsrc, u32 level);
+};
+
+struct mtk_dvfsrc {
+	struct device *dev;
+	struct platform_device *icc;
+	struct platform_device *regulator;
+	const struct dvfsrc_soc_data *dvd;
+	int dram_type;
+	const struct dvfsrc_opp_desc *curr_opps;
+	void __iomem *regs;
+	spinlock_t req_lock;
+	struct mutex pstate_lock;
+	struct notifier_block scpsys_notifier;
+};
+
+static u32 dvfsrc_read(struct mtk_dvfsrc *dvfs, u32 offset)
+{
+	return readl(dvfs->regs + dvfs->dvd->regs[offset]);
+}
+
+static void dvfsrc_write(struct mtk_dvfsrc *dvfs, u32 offset, u32 val)
+{
+	writel(val, dvfs->regs + dvfs->dvd->regs[offset]);
+}
+
+#define dvfsrc_rmw(dvfs, offset, val, mask, shift) \
+	dvfsrc_write(dvfs, offset, \
+		(dvfsrc_read(dvfs, offset) & ~(mask << shift)) | (val << shift))
+
+enum dvfsrc_regs {
+	DVFSRC_SW_REQ,
+	DVFSRC_SW_REQ2,
+	DVFSRC_LEVEL,
+	DVFSRC_TARGET_LEVEL,
+	DVFSRC_SW_BW,
+	DVFSRC_SW_PEAK_BW,
+	DVFSRC_SW_HRT_BW,
+	DVFSRC_VCORE_REQUEST,
+};
+
+static const int mt8183_regs[] = {
+	[DVFSRC_SW_REQ] =	0x4,
+	[DVFSRC_SW_REQ2] =	0x8,
+	[DVFSRC_LEVEL] =	0xDC,
+	[DVFSRC_SW_BW] =	0x160,
+};
+
+static const struct dvfsrc_opp *get_current_opp(struct mtk_dvfsrc *dvfsrc)
+{
+	int level;
+
+	level = dvfsrc->dvd->get_current_level(dvfsrc);
+	return &dvfsrc->curr_opps->opps[level];
+}
+
+static int dvfsrc_is_idle(struct mtk_dvfsrc *dvfsrc)
+{
+	if (!dvfsrc->dvd->get_target_level)
+		return true;
+
+	return dvfsrc->dvd->get_target_level(dvfsrc);
+}
+
+static int dvfsrc_wait_for_vcore_level(struct mtk_dvfsrc *dvfsrc, u32 level)
+{
+	const struct dvfsrc_opp *curr;
+
+	return readx_poll_timeout_atomic(get_current_opp, dvfsrc, curr,
+					 curr->vcore_opp >= level, STARTUP_TIME,
+					 POLL_TIMEOUT);
+}
+
+static int mt8183_wait_for_opp_level(struct mtk_dvfsrc *dvfsrc, u32 level)
+{
+	const struct dvfsrc_opp *target, *curr;
+	int ret;
+
+	target = &dvfsrc->curr_opps->opps[level];
+	ret = readx_poll_timeout(get_current_opp, dvfsrc, curr,
+				 curr->dram_opp >= target->dram_opp &&
+				 curr->vcore_opp >= target->vcore_opp,
+				 STARTUP_TIME, POLL_TIMEOUT);
+	if (ret < 0) {
+		dev_warn(dvfsrc->dev,
+			 "timeout, target: %u, dram: %d, vcore: %d\n", level,
+			 curr->dram_opp, curr->vcore_opp);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int mt8183_get_target_level(struct mtk_dvfsrc *dvfsrc)
+{
+	return DVFSRC_GET_TARGET_LEVEL(dvfsrc_read(dvfsrc, DVFSRC_LEVEL));
+}
+
+static int mt8183_get_current_level(struct mtk_dvfsrc *dvfsrc)
+{
+	int level;
+
+	/* HW level 0 is begin from 0x10000 */
+	level = DVFSRC_GET_CURRENT_LEVEL(dvfsrc_read(dvfsrc, DVFSRC_LEVEL));
+	/* Array index start from 0 */
+	return ffs(level) - 1;
+}
+
+static u32 mt8183_get_vcore_level(struct mtk_dvfsrc *dvfsrc)
+{
+	return (dvfsrc_read(dvfsrc, DVFSRC_SW_REQ2) >> 2) & 0x3;
+}
+
+static void mt8183_set_dram_bw(struct mtk_dvfsrc *dvfsrc, u64 bw)
+{
+	dvfsrc_write(dvfsrc, DVFSRC_SW_BW, div_u64(kbps_to_mbps(bw), 100));
+}
+
+static void mt8183_set_opp_level(struct mtk_dvfsrc *dvfsrc, u32 level)
+{
+	int vcore_opp, dram_opp;
+	const struct dvfsrc_opp *opp;
+
+	/* translate pstate to dvfsrc level, and set it to DVFSRC HW */
+	opp = &dvfsrc->curr_opps->opps[level];
+	vcore_opp = opp->vcore_opp;
+	dram_opp = opp->dram_opp;
+
+	dev_dbg(dvfsrc->dev, "vcore_opp: %d, dram_opp: %d\n",
+		vcore_opp, dram_opp);
+	dvfsrc_write(dvfsrc, DVFSRC_SW_REQ, dram_opp | vcore_opp << 2);
+}
+
+static void mt8183_set_vcore_level(struct mtk_dvfsrc *dvfsrc, u32 level)
+{
+	dvfsrc_write(dvfsrc, DVFSRC_SW_REQ2, level << 2);
+}
+
+void mtk_dvfsrc_send_request(const struct device *dev, u32 cmd, u64 data)
+{
+	int ret, state;
+	struct mtk_dvfsrc *dvfsrc = dev_get_drvdata(dev);
+
+	dev_dbg(dvfsrc->dev, "cmd: %d, data: %llu\n", cmd, data);
+
+	switch (cmd) {
+	case MTK_DVFSRC_CMD_BW_REQUEST:
+		dvfsrc->dvd->set_dram_bw(dvfsrc, data);
+		return;
+	case MTK_DVFSRC_CMD_PEAK_BW_REQUEST:
+		if (dvfsrc->dvd->set_dram_peak_bw)
+			dvfsrc->dvd->set_dram_peak_bw(dvfsrc, data);
+		return;
+	case MTK_DVFSRC_CMD_OPP_REQUEST:
+		if (dvfsrc->dvd->set_opp_level)
+			dvfsrc->dvd->set_opp_level(dvfsrc, data);
+		break;
+	case MTK_DVFSRC_CMD_VCORE_REQUEST:
+		dvfsrc->dvd->set_vcore_level(dvfsrc, data);
+		break;
+	case MTK_DVFSRC_CMD_HRTBW_REQUEST:
+		if (dvfsrc->dvd->set_dram_hrtbw)
+			dvfsrc->dvd->set_dram_hrtbw(dvfsrc, data);
+		else
+			return;
+		break;
+	case MTK_DVFSRC_CMD_VSCP_REQUEST:
+		dvfsrc->dvd->set_vscp_level(dvfsrc, data);
+		break;
+	default:
+		dev_err(dvfsrc->dev, "unknown command: %d\n", cmd);
+		return;
+	}
+
+	/* DVFSRC need to wait at least 2T(~196ns) to handle request
+	 * after recieving command
+	 */
+	udelay(STARTUP_TIME);
+
+	ret = readx_poll_timeout(dvfsrc_is_idle, dvfsrc,
+				 state, state == DVFSRC_IDLE,
+				 STARTUP_TIME, POLL_TIMEOUT);
+
+	if (ret < 0) {
+		dev_warn(dvfsrc->dev,
+			 "%d: idle timeout, data: %llu, last: %d -> %d\n",
+			 cmd, data,
+			 dvfsrc->dvd->get_current_level(dvfsrc),
+			 dvfsrc->dvd->get_target_level(dvfsrc));
+		return;
+	}
+
+	/* The previous change may be requested by previous request.
+	 * So we delay 1us, then start checking opp is reached enough.
+	 */
+	udelay(STARTUP_TIME);
+
+	if (cmd == MTK_DVFSRC_CMD_OPP_REQUEST)
+		ret = dvfsrc->dvd->wait_for_opp_level(dvfsrc, data);
+	else
+		ret = dvfsrc->dvd->wait_for_vcore_level(dvfsrc, data);
+
+	if (ret < 0) {
+		dev_warn(dvfsrc->dev,
+			 "%d: wait timeout, data: %llu, last: %d -> %d\n",
+			 cmd, data,
+			 dvfsrc->dvd->get_current_level(dvfsrc),
+			 dvfsrc->dvd->get_target_level(dvfsrc));
+	}
+
+}
+EXPORT_SYMBOL(mtk_dvfsrc_send_request);
+
+int mtk_dvfsrc_query_info(const struct device *dev, u32 cmd, int *data)
+{
+	struct mtk_dvfsrc *dvfsrc = dev_get_drvdata(dev);
+
+	switch (cmd) {
+	case MTK_DVFSRC_CMD_VCORE_LEVEL_QUERY:
+		*data = dvfsrc->dvd->get_vcore_level(dvfsrc);
+		break;
+	case MTK_DVFSRC_CMD_VSCP_LEVEL_QUERY:
+		*data = dvfsrc->dvd->get_vcp_level(dvfsrc);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(mtk_dvfsrc_query_info);
+
+static int mtk_dvfsrc_probe(struct platform_device *pdev)
+{
+	struct arm_smccc_res ares;
+	struct resource *res;
+	struct mtk_dvfsrc *dvfsrc;
+	int ret;
+
+	dvfsrc = devm_kzalloc(&pdev->dev, sizeof(*dvfsrc), GFP_KERNEL);
+	if (!dvfsrc)
+		return -ENOMEM;
+
+	dvfsrc->dvd = of_device_get_match_data(&pdev->dev);
+	dvfsrc->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	dvfsrc->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(dvfsrc->regs))
+		return PTR_ERR(dvfsrc->regs);
+
+	spin_lock_init(&dvfsrc->req_lock);
+	mutex_init(&dvfsrc->pstate_lock);
+
+	arm_smccc_smc(MTK_SIP_VCOREFS_CONTROL, MTK_SIP_DVFSRC_INIT, 0, 0, 0,
+		0, 0, 0, &ares);
+
+	if (!ares.a0) {
+		dvfsrc->dram_type = ares.a1;
+		dev_info(dvfsrc->dev, "dram_type: %d\n", dvfsrc->dram_type);
+	} else {
+		dev_err(dvfsrc->dev, "init fails: %lu\n", ares.a0);
+		return ares.a0;
+	}
+
+	dvfsrc->curr_opps = &dvfsrc->dvd->opps_desc[dvfsrc->dram_type];
+	platform_set_drvdata(pdev, dvfsrc);
+
+	dvfsrc->regulator = platform_device_register_data(dvfsrc->dev,
+			"mtk-dvfsrc-regulator", -1, NULL, 0);
+	if (IS_ERR(dvfsrc->regulator)) {
+		dev_err(dvfsrc->dev, "Failed create regulator device\n");
+		ret = PTR_ERR(dvfsrc->regulator);
+		goto err;
+	}
+
+	dvfsrc->icc = platform_device_register_data(dvfsrc->dev,
+			"mediatek-emi-icc", -1, NULL, 0);
+	if (IS_ERR(dvfsrc->icc)) {
+		dev_err(dvfsrc->dev, "Failed create icc device\n");
+		ret = PTR_ERR(dvfsrc->icc);
+		goto unregister_regulator;
+	}
+
+	ret = devm_of_platform_populate(&pdev->dev);
+	if (ret)
+		platform_device_unregister(dvfsrc->icc);
+
+	return 0;
+
+unregister_regulator:
+	platform_device_unregister(dvfsrc->regulator);
+err:
+	return ret;
+}
+
+static const struct dvfsrc_opp dvfsrc_opp_mt8183_lp4[] = {
+	{0, 0}, {0, 1}, {0, 2}, {1, 2},
+};
+
+static const struct dvfsrc_opp dvfsrc_opp_mt8183_lp3[] = {
+	{0, 0}, {0, 1}, {1, 1}, {1, 2},
+};
+
+static const struct dvfsrc_opp_desc dvfsrc_opp_mt8183_desc[] = {
+	DVFSRC_OPP_DESC(dvfsrc_opp_mt8183_lp4),
+	DVFSRC_OPP_DESC(dvfsrc_opp_mt8183_lp3),
+	DVFSRC_OPP_DESC(dvfsrc_opp_mt8183_lp3),
+};
+
+static const struct dvfsrc_soc_data mt8183_data = {
+	.opps_desc = dvfsrc_opp_mt8183_desc,
+	.regs = mt8183_regs,
+	.get_target_level = mt8183_get_target_level,
+	.get_current_level = mt8183_get_current_level,
+	.get_vcore_level = mt8183_get_vcore_level,
+	.set_dram_bw = mt8183_set_dram_bw,
+	.set_opp_level = mt8183_set_opp_level,
+	.set_vcore_level = mt8183_set_vcore_level,
+	.wait_for_opp_level = mt8183_wait_for_opp_level,
+	.wait_for_vcore_level = dvfsrc_wait_for_vcore_level,
+};
+
+static int mtk_dvfsrc_remove(struct platform_device *pdev)
+{
+	struct mtk_dvfsrc *dvfsrc = platform_get_drvdata(pdev);
+
+	platform_device_unregister(dvfsrc->regulator);
+	platform_device_unregister(dvfsrc->icc);
+
+	return 0;
+}
+
+static const struct of_device_id mtk_dvfsrc_of_match[] = {
+	{
+		.compatible = "mediatek,mt8183-dvfsrc",
+		.data = &mt8183_data,
+	}, {
+		/* sentinel */
+	},
+};
+
+static struct platform_driver mtk_dvfsrc_driver = {
+	.probe	= mtk_dvfsrc_probe,
+	.remove	= mtk_dvfsrc_remove,
+	.driver = {
+		.name = "mtk-dvfsrc",
+		.of_match_table = of_match_ptr(mtk_dvfsrc_of_match),
+	},
+};
+
+static int __init mtk_dvfsrc_init(void)
+{
+	return platform_driver_register(&mtk_dvfsrc_driver);
+}
+subsys_initcall(mtk_dvfsrc_init);
+
+static void __exit mtk_dvfsrc_exit(void)
+{
+	platform_driver_unregister(&mtk_dvfsrc_driver);
+}
+module_exit(mtk_dvfsrc_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MTK DVFSRC driver");
diff --git a/include/linux/soc/mediatek/mtk_dvfsrc.h b/include/linux/soc/mediatek/mtk_dvfsrc.h
new file mode 100644
index 0000000..823eff9
--- /dev/null
+++ b/include/linux/soc/mediatek/mtk_dvfsrc.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (c) 2021 MediaTek Inc.
+ */
+
+#ifndef __SOC_MTK_DVFSRC_H
+#define __SOC_MTK_DVFSRC_H
+
+#define MTK_DVFSRC_CMD_BW_REQUEST		0
+#define MTK_DVFSRC_CMD_OPP_REQUEST		1
+#define MTK_DVFSRC_CMD_VCORE_REQUEST		2
+#define MTK_DVFSRC_CMD_HRTBW_REQUEST		3
+#define MTK_DVFSRC_CMD_VSCP_REQUEST		4
+#define MTK_DVFSRC_CMD_PEAK_BW_REQUEST		5
+
+#define MTK_DVFSRC_CMD_VCORE_LEVEL_QUERY	0
+#define MTK_DVFSRC_CMD_VSCP_LEVEL_QUERY		1
+
+#if IS_ENABLED(CONFIG_MTK_DVFSRC)
+void mtk_dvfsrc_send_request(const struct device *dev, u32 cmd, u64 data);
+int mtk_dvfsrc_query_info(const struct device *dev, u32 cmd, int *data);
+
+#else
+
+static inline void mtk_dvfsrc_send_request(const struct device *dev, u32 cmd,
+					   u64 data)
+{ return -ENODEV; }
+
+static inline int mtk_dvfsrc_query_info(const struct device *dev, u32 cmd,
+					int *data);
+{ return -ENODEV; }
+
+#endif /* CONFIG_MTK_DVFSRC */
+
+#endif
-- 
1.9.1