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From:   Vijendar Mukunda <Vijendar.Mukunda@amd.com>
To:     <broonie@kernel.org>, <vkoul@kernel.org>,
        <alsa-devel@alsa-project.org>
CC:     <Basavaraj.Hiregoudar@amd.com>, <Sunil-kumar.Dommati@amd.com>,
        <Mario.Limonciello@amd.com>, <Mastan.Katragadda@amd.com>,
        <arungopal.kondaveeti@amd.com>,
        Vijendar Mukunda <Vijendar.Mukunda@amd.com>,
        Bard Liao <yung-chuan.liao@linux.intel.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
        Sanyog Kale <sanyog.r.kale@intel.com>,
        open list <linux-kernel@vger.kernel.org>
Subject: [PATCH 14/19] soundwire: amd: add runtime pm ops for AMD master driver
Date:   Wed, 11 Jan 2023 14:32:17 +0530
Message-ID: <20230111090222.2016499-15-Vijendar.Mukunda@amd.com>
In-Reply-To: <20230111090222.2016499-1-Vijendar.Mukunda@amd.com>
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Add support for runtime pm ops for AMD master driver.

Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Signed-off-by: Mastan Katragadda <Mastan.Katragadda@amd.com>
---
 drivers/soundwire/amd_master.c    | 205 ++++++++++++++++++++++++++++++
 drivers/soundwire/amd_master.h    |   3 +
 include/linux/soundwire/sdw_amd.h |   1 +
 3 files changed, 209 insertions(+)

diff --git a/drivers/soundwire/amd_master.c b/drivers/soundwire/amd_master.c
index c7063b8bdd7b..d2d7f07de202 100644
--- a/drivers/soundwire/amd_master.c
+++ b/drivers/soundwire/amd_master.c
@@ -15,6 +15,7 @@
 #include <linux/soundwire/sdw.h>
 #include <linux/soundwire/sdw_registers.h>
 #include <linux/soundwire/sdw_amd.h>
+#include <linux/pm_runtime.h>
 #include <linux/wait.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
@@ -290,6 +291,17 @@ static int amd_disable_sdw_interrupts(struct amd_sdwc_ctrl *ctrl)
 	return 0;
 }
 
+static int amd_deinit_sdw_controller(struct amd_sdwc_ctrl *ctrl)
+{
+	int ret;
+
+	ret = amd_disable_sdw_interrupts(ctrl);
+	if (ret)
+		return ret;
+	ret = amd_disable_sdw_controller(ctrl);
+	return ret;
+}
+
 static int amd_sdwc_set_frameshape(struct amd_sdwc_ctrl *ctrl, u32 rows, u32 cols)
 {
 	u32 sdw_rows, sdw_cols, frame_size;
@@ -1387,6 +1399,12 @@ static int amd_sdwc_probe(struct platform_device *pdev)
 	INIT_WORK(&ctrl->amd_sdw_work, amd_sdwc_update_slave_status_work);
 	INIT_WORK(&ctrl->probe_work, amd_sdwc_probe_work);
 	schedule_work(&ctrl->probe_work);
+	/* Enable runtime PM */
+	pm_runtime_set_autosuspend_delay(dev, AMD_SDW_MASTER_SUSPEND_DELAY_MS);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
 	return 0;
 }
 
@@ -1398,14 +1416,201 @@ static int amd_sdwc_remove(struct platform_device *pdev)
 	amd_disable_sdw_interrupts(ctrl);
 	sdw_bus_master_delete(&ctrl->bus);
 	ret = amd_disable_sdw_controller(ctrl);
+	pm_runtime_disable(&pdev->dev);
 	return ret;
 }
 
+static int amd_sdwc_clock_stop(struct amd_sdwc_ctrl *ctrl)
+{
+	u32 clk_resume_ctrl_reg;
+	u32 wake_en_reg;
+	u32 val;
+	u32 retry_count = 0;
+	int ret;
+
+	ret = sdw_bus_prep_clk_stop(&ctrl->bus);
+	if (ret < 0 && ret != -ENODATA) {
+		dev_err(ctrl->dev, "prepare clock stop failed %d", ret);
+		return ret;
+	}
+	ret = sdw_bus_clk_stop(&ctrl->bus);
+	if (ret < 0 && ret != -ENODATA) {
+		dev_err(ctrl->dev, "bus clock stop failed %d", ret);
+		return ret;
+	}
+	switch (ctrl->instance) {
+	case ACP_SDW0:
+		clk_resume_ctrl_reg = ACP_SW_CLK_RESUME_CTRL;
+		wake_en_reg = ACP_SW_WAKE_EN;
+		break;
+	case ACP_SDW1:
+		clk_resume_ctrl_reg = ACP_P1_SW_CLK_RESUME_CTRL;
+		wake_en_reg = ACP_SW1_WAKE_EN;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	do {
+		val = acp_reg_readl(ctrl->mmio + clk_resume_ctrl_reg);
+		if (val & AMD_SDW_CLK_STOP_DONE) {
+			ctrl->clk_stopped = true;
+			break;
+		}
+	} while (retry_count++ < AMD_SDW_CLK_STOP_MAX_RETRY_COUNT);
+
+	if (!ctrl->clk_stopped) {
+		dev_err(ctrl->dev, "SDW%x clock stop failed\n", ctrl->instance);
+		return -ETIMEDOUT;
+	}
+
+	if (ctrl->wake_en_mask)
+		acp_reg_writel(0x01, ctrl->mmio + wake_en_reg);
+
+	dev_dbg(ctrl->dev, "SDW%x clock stop successful\n", ctrl->instance);
+	return 0;
+}
+
+static int amd_sdwc_clock_stop_exit(struct amd_sdwc_ctrl *ctrl)
+{
+	int ret;
+	u32 clk_resume_ctrl_reg;
+	u32 val = 0;
+	u32 retry_count = 0;
+
+	switch (ctrl->instance) {
+	case ACP_SDW0:
+		clk_resume_ctrl_reg = ACP_SW_CLK_RESUME_CTRL;
+		break;
+	case ACP_SDW1:
+		clk_resume_ctrl_reg = ACP_P1_SW_CLK_RESUME_CTRL;
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (ctrl->clk_stopped) {
+		val = acp_reg_readl(ctrl->mmio + clk_resume_ctrl_reg);
+		val |= AMD_SDW_CLK_RESUME_REQ;
+		acp_reg_writel(val, ctrl->mmio + clk_resume_ctrl_reg);
+		do {
+			val = acp_reg_readl(ctrl->mmio + clk_resume_ctrl_reg);
+			if (val & AMD_SDW_CLK_RESUME_DONE)
+				break;
+			usleep_range(10, 100);
+		} while (retry_count++ < AMD_SDW_CLK_STOP_MAX_RETRY_COUNT);
+		if (val & AMD_SDW_CLK_RESUME_DONE) {
+			acp_reg_writel(0, ctrl->mmio + clk_resume_ctrl_reg);
+			ret = sdw_bus_exit_clk_stop(&ctrl->bus);
+			if (ret < 0)
+				dev_err(ctrl->dev, "bus failed to exit clock stop %d\n", ret);
+			ctrl->clk_stopped = false;
+		}
+	}
+	if (ctrl->clk_stopped) {
+		dev_err(ctrl->dev, "SDW%x clock stop exit failed\n", ctrl->instance);
+		return -ETIMEDOUT;
+	}
+
+	dev_dbg(ctrl->dev, "SDW%x clock stop exit successful\n", ctrl->instance);
+
+	return 0;
+}
+
+static int __maybe_unused amd_suspend_runtime(struct device *dev)
+{
+	struct amd_sdwc_ctrl *ctrl = dev_get_drvdata(dev);
+	struct sdw_bus *bus = &ctrl->bus;
+	int ret;
+
+	if (bus->prop.hw_disabled || !ctrl->startup_done) {
+		dev_dbg(bus->dev, "SoundWire master %d is disabled or not-started, ignoring\n",
+			bus->link_id);
+		return 0;
+	}
+	if (ctrl->power_mode_mask & AMD_SDW_CLK_STOP_MODE) {
+		ret = amd_sdwc_clock_stop(ctrl);
+		if (ret)
+			return ret;
+	} else if (ctrl->power_mode_mask & AMD_SDW_POWER_OFF_MODE) {
+		ret = amd_sdwc_clock_stop(ctrl);
+		if (ret)
+			return ret;
+		ret = amd_deinit_sdw_controller(ctrl);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
+static int __maybe_unused amd_resume_runtime(struct device *dev)
+{
+	struct amd_sdwc_ctrl *ctrl = dev_get_drvdata(dev);
+	struct sdw_bus *bus = &ctrl->bus;
+	int ret;
+	u32 clk_resume_ctrl_reg;
+	u32 val = 0;
+	u32 retry_count = 0;
+
+	if (bus->prop.hw_disabled || !ctrl->startup_done) {
+		dev_dbg(bus->dev, "SoundWire master %d is disabled or not-started, ignoring\n",
+			bus->link_id);
+		return 0;
+	}
+
+	switch (ctrl->instance) {
+	case ACP_SDW0:
+		clk_resume_ctrl_reg = ACP_SW_CLK_RESUME_CTRL;
+		break;
+	case ACP_SDW1:
+		clk_resume_ctrl_reg = ACP_P1_SW_CLK_RESUME_CTRL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (ctrl->power_mode_mask & AMD_SDW_CLK_STOP_MODE) {
+		ret = amd_sdwc_clock_stop_exit(ctrl);
+		if (ret)
+			return ret;
+	} else if (ctrl->power_mode_mask & AMD_SDW_POWER_OFF_MODE) {
+		val = acp_reg_readl(ctrl->mmio + clk_resume_ctrl_reg);
+		if (val) {
+			val |= AMD_SDW_CLK_RESUME_REQ;
+			acp_reg_writel(val, ctrl->mmio + clk_resume_ctrl_reg);
+			do {
+				val = acp_reg_readl(ctrl->mmio + clk_resume_ctrl_reg);
+				if (val & AMD_SDW_CLK_RESUME_DONE)
+					break;
+				usleep_range(10, 100);
+			} while (retry_count++ < AMD_SDW_CLK_STOP_MAX_RETRY_COUNT);
+			if (val & AMD_SDW_CLK_RESUME_DONE) {
+				acp_reg_writel(0, ctrl->mmio + clk_resume_ctrl_reg);
+				ctrl->clk_stopped = false;
+			}
+		}
+		sdw_clear_slave_status(bus, SDW_UNATTACH_REQUEST_MASTER_RESET);
+		amd_init_sdw_controller(ctrl);
+		amd_enable_sdw_interrupts(ctrl);
+		ret = amd_enable_sdw_controller(ctrl);
+		if (ret)
+			return ret;
+		ret = amd_sdwc_set_frameshape(ctrl, 50, 10);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
+static const struct dev_pm_ops amd_pm = {
+	SET_RUNTIME_PM_OPS(amd_suspend_runtime, amd_resume_runtime, NULL)
+};
+
 static struct platform_driver amd_sdwc_driver = {
 	.probe	= &amd_sdwc_probe,
 	.remove = &amd_sdwc_remove,
 	.driver = {
 		.name	= "amd_sdw_controller",
+		.pm = &amd_pm,
 	}
 };
 module_platform_driver(amd_sdwc_driver);
diff --git a/drivers/soundwire/amd_master.h b/drivers/soundwire/amd_master.h
index b43a5d6496cb..cc254255512b 100644
--- a/drivers/soundwire/amd_master.h
+++ b/drivers/soundwire/amd_master.h
@@ -237,6 +237,9 @@
 #define AMD_SDW0_PAD_KEEPER_DISABLE_MASK        0x1E
 #define AMD_SDW1_PAD_KEEPER_DISABLE_MASK	0xF
 #define AMD_SDW_PREQ_INTR_STAT  BIT(19)
+#define AMD_SDW_CLK_STOP_DONE		1
+#define AMD_SDW_CLK_RESUME_REQ		2
+#define AMD_SDW_CLK_RESUME_DONE		3
 
 enum amd_sdw_channel {
 	/* SDW0 */
diff --git a/include/linux/soundwire/sdw_amd.h b/include/linux/soundwire/sdw_amd.h
index 2db03b2f0c3b..f362f195b887 100644
--- a/include/linux/soundwire/sdw_amd.h
+++ b/include/linux/soundwire/sdw_amd.h
@@ -38,6 +38,7 @@ struct amd_sdwc_ctrl {
 	u32 quirks;
 	u32 wake_en_mask;
 	int num_ports;
+	bool clk_stopped;
 	bool startup_done;
 	u32 power_mode_mask;
 };
-- 
2.34.1