On 2/28/22 11:25, Srinivas Kandagatla wrote:
> Add support to runtime PM using SoundWire clock stop Mode0 on supported
> controller instances and soft reset on instances that do not support
> clock stop.
>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> ---
> drivers/soundwire/qcom.c | 156 ++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 155 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
> index 54813417ef8e..810232686196 100644
> --- a/drivers/soundwire/qcom.c
> +++ b/drivers/soundwire/qcom.c
> @@ -11,6 +11,7 @@
> #include <linux/of.h>
> #include <linux/of_irq.h>
> #include <linux/of_device.h>
> +#include <linux/pm_runtime.h>
> #include <linux/regmap.h>
> #include <linux/slab.h>
> #include <linux/slimbus.h>
> @@ -20,6 +21,9 @@
> #include <sound/soc.h>
> #include "bus.h"
>
> +#define SWRM_COMP_SW_RESET 0x008
> +#define SWRM_COMP_STATUS 0x014
> +#define SWRM_FRM_GEN_ENABLED BIT(0)
> #define SWRM_COMP_HW_VERSION 0x00
> #define SWRM_COMP_CFG_ADDR 0x04
> #define SWRM_COMP_CFG_IRQ_LEVEL_OR_PULSE_MSK BIT(1)
> @@ -29,6 +33,7 @@
> #define SWRM_COMP_PARAMS_RD_FIFO_DEPTH GENMASK(19, 15)
> #define SWRM_COMP_PARAMS_DOUT_PORTS_MASK GENMASK(4, 0)
> #define SWRM_COMP_PARAMS_DIN_PORTS_MASK GENMASK(9, 5)
> +#define SWRM_COMP_MASTER_ID 0x104
> #define SWRM_INTERRUPT_STATUS 0x200
> #define SWRM_INTERRUPT_STATUS_RMSK GENMASK(16, 0)
> #define SWRM_INTERRUPT_STATUS_SLAVE_PEND_IRQ BIT(0)
> @@ -111,6 +116,13 @@
> #define SWR_MAX_CMD_ID 14
> #define MAX_FIFO_RD_RETRY 3
> #define SWR_OVERFLOW_RETRY_COUNT 30
> +#define SWRM_LINK_STATUS_RETRY_CNT 100
> +
> +enum {
> + MASTER_ID_WSA = 1,
> + MASTER_ID_RX,
> + MASTER_ID_TX
> +};
>
> struct qcom_swrm_port_config {
> u8 si;
> @@ -159,6 +171,7 @@ struct qcom_swrm_ctrl {
> u32 slave_status;
> u32 wr_fifo_depth;
> u32 rd_fifo_depth;
> + bool clock_stop_not_supported;
> };
>
> struct qcom_swrm_data {
> @@ -497,6 +510,7 @@ static irqreturn_t qcom_swrm_irq_handler(int irq, void *dev_id)
> u32 i;
> int devnum;
> int ret = IRQ_HANDLED;
> + clk_prepare_enable(swrm->hclk);
>
> swrm->reg_read(swrm, SWRM_INTERRUPT_STATUS, &intr_sts);
> intr_sts_masked = intr_sts & swrm->intr_mask;
> @@ -604,6 +618,7 @@ static irqreturn_t qcom_swrm_irq_handler(int irq, void *dev_id)
> intr_sts_masked = intr_sts & swrm->intr_mask;
> } while (intr_sts_masked);
>
> + clk_disable_unprepare(swrm->hclk);
> return ret;
> }
>
> @@ -1017,6 +1032,15 @@ static int qcom_swrm_startup(struct snd_pcm_substream *substream,
> struct snd_soc_dai *codec_dai;
> int ret, i;
>
> + ret = pm_runtime_get_sync(ctrl->dev);
> + if (ret < 0 && ret != -EACCES) {
> + dev_err_ratelimited(ctrl->dev,
> + "pm_runtime_get_sync failed in %s, ret %d\n",
> + __func__, ret);
> + pm_runtime_put_noidle(ctrl->dev);
> + return ret;
> + }
> +
> sruntime = sdw_alloc_stream(dai->name);
> if (!sruntime)
> return -ENOMEM;
> @@ -1044,6 +1068,9 @@ static void qcom_swrm_shutdown(struct snd_pcm_substream *substream,
>
> sdw_release_stream(ctrl->sruntime[dai->id]);
> ctrl->sruntime[dai->id] = NULL;
> + pm_runtime_mark_last_busy(ctrl->dev);
> + pm_runtime_put_autosuspend(ctrl->dev);
> +
> }
>
> static const struct snd_soc_dai_ops qcom_swrm_pdm_dai_ops = {
> @@ -1197,12 +1224,23 @@ static int qcom_swrm_get_port_config(struct qcom_swrm_ctrl *ctrl)
> static int swrm_reg_show(struct seq_file *s_file, void *data)
> {
> struct qcom_swrm_ctrl *swrm = s_file->private;
> - int reg, reg_val;
> + int reg, reg_val, ret;
> +
> + ret = pm_runtime_get_sync(swrm->dev);
> + if (ret < 0 && ret != -EACCES) {
> + dev_err_ratelimited(swrm->dev,
> + "pm_runtime_get_sync failed in %s, ret %d\n",
> + __func__, ret);
> + pm_runtime_put_noidle(swrm->dev);
> + }
>
> for (reg = 0; reg <= SWR_MSTR_MAX_REG_ADDR; reg += 4) {
> swrm->reg_read(swrm, reg, ®_val);
> seq_printf(s_file, "0x%.3x: 0x%.2x\n", reg, reg_val);
> }
> + pm_runtime_mark_last_busy(swrm->dev);
> + pm_runtime_put_autosuspend(swrm->dev);
> +
>
> return 0;
> }
> @@ -1267,6 +1305,7 @@ static int qcom_swrm_probe(struct platform_device *pdev)
> ctrl->bus.ops = &qcom_swrm_ops;
> ctrl->bus.port_ops = &qcom_swrm_port_ops;
> ctrl->bus.compute_params = &qcom_swrm_compute_params;
> + ctrl->bus.clk_stop_timeout = 300;
>
> ret = qcom_swrm_get_port_config(ctrl);
> if (ret)
> @@ -1319,6 +1358,21 @@ static int qcom_swrm_probe(struct platform_device *pdev)
> (ctrl->version >> 24) & 0xff, (ctrl->version >> 16) & 0xff,
> ctrl->version & 0xffff);
>
> + pm_runtime_set_autosuspend_delay(dev, 3000);
> + pm_runtime_use_autosuspend(dev);
> + pm_runtime_mark_last_busy(dev);
> + pm_runtime_set_active(dev);
> + pm_runtime_enable(dev);
> +
> + /* Clk stop is not supported on WSA Soundwire masters */
> + if (ctrl->version <= 0x01030000) {
> + ctrl->clock_stop_not_supported = true;
> + } else {
> + ctrl->reg_read(ctrl, SWRM_COMP_MASTER_ID, &val);
> + if (val == MASTER_ID_WSA)
> + ctrl->clock_stop_not_supported = true;
> + }
> +
> #ifdef CONFIG_DEBUG_FS
> ctrl->debugfs = debugfs_create_dir("qualcomm-sdw", ctrl->bus.debugfs);
> debugfs_create_file("qualcomm-registers", 0400, ctrl->debugfs, ctrl,
> @@ -1345,6 +1399,105 @@ static int qcom_swrm_remove(struct platform_device *pdev)
> return 0;
> }
>
> +static bool swrm_wait_for_frame_gen_enabled(struct qcom_swrm_ctrl *swrm)
> +{
> + int retry = SWRM_LINK_STATUS_RETRY_CNT;
> + int comp_sts;
> +
> + do {
> + swrm->reg_read(swrm, SWRM_COMP_STATUS, &comp_sts);
> +
> + if (comp_sts & SWRM_FRM_GEN_ENABLED)
> + return true;
> +
> + usleep_range(500, 510);
> + } while (retry--);
> +
> + dev_err(swrm->dev, "%s: link status not %s\n", __func__,
> + comp_sts && SWRM_FRM_GEN_ENABLED ? "connected" : "disconnected");
> +
> + return false;
> +}
> +
> +static int swrm_runtime_resume(struct device *dev)
> +{
> + struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dev);
> + int ret;
> +
> + clk_prepare_enable(ctrl->hclk);
> +
> + if (ctrl->clock_stop_not_supported) {
> + reinit_completion(&ctrl->enumeration);
> + ctrl->reg_write(ctrl, SWRM_COMP_SW_RESET, 0x01);
> + usleep_range(100, 105);
> +
> + qcom_swrm_init(ctrl);
> +
> + usleep_range(100, 105);
> + if (!swrm_wait_for_frame_gen_enabled(ctrl))
> + dev_err(ctrl->dev, "link failed to connect\n");
> +
> + /* wait for hw enumeration to complete */
> + wait_for_completion_timeout(&ctrl->enumeration,
> + msecs_to_jiffies(TIMEOUT_MS));
> + qcom_swrm_get_device_status(ctrl);
> + sdw_handle_slave_status(&ctrl->bus, ctrl->status);
> + } else {
> + ctrl->reg_write(ctrl, SWRM_MCP_BUS_CTRL, SWRM_MCP_BUS_CLK_START);
> + ctrl->reg_write(ctrl, SWRM_INTERRUPT_CLEAR,
> + SWRM_INTERRUPT_STATUS_MASTER_CLASH_DET);
> +
> + ctrl->intr_mask |= SWRM_INTERRUPT_STATUS_MASTER_CLASH_DET;
> + ctrl->reg_write(ctrl, SWRM_INTERRUPT_MASK_ADDR, ctrl->intr_mask);
> + ctrl->reg_write(ctrl, SWRM_INTERRUPT_CPU_EN, ctrl->intr_mask);
> +
> + usleep_range(100, 105);
> + if (!swrm_wait_for_frame_gen_enabled(ctrl))
> + dev_err(ctrl->dev, "link failed to connect\n");
> +
> + ret = sdw_bus_exit_clk_stop(&ctrl->bus);
> + if (ret < 0)
> + dev_err(ctrl->dev, "bus failed to exit clock stop %d\n", ret);
> + }
> +
> + return 0;
> +}
> +
> +static int __maybe_unused swrm_runtime_suspend(struct device *dev)
> +{
> + struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dev);
> + int ret;
> +
> + if (!ctrl->clock_stop_not_supported) {
> + /* Mask bus clash interrupt */
> + ctrl->intr_mask &= ~SWRM_INTERRUPT_STATUS_MASTER_CLASH_DET;
> + ctrl->reg_write(ctrl, SWRM_INTERRUPT_MASK_ADDR, ctrl->intr_mask);
> + ctrl->reg_write(ctrl, SWRM_INTERRUPT_CPU_EN, ctrl->intr_mask);
> + /* Prepare slaves for clock stop */
> + ret = sdw_bus_prep_clk_stop(&ctrl->bus);
> + if (ret < 0 && ret != -ENODATA) {
> + dev_err(dev, "prepare clock stop failed %d", ret);
> + return ret;
> + }
> +
> + ret = sdw_bus_clk_stop(&ctrl->bus);
> + if (ret < 0 && ret != -ENODATA) {
> + dev_err(dev, "bus clock stop failed %d", ret);
> + return ret;
> + }
> + }
> +
> + clk_disable_unprepare(ctrl->hclk);
> +
> + usleep_range(300, 305);
> +
> + return 0;
> +}
> +
> +static const struct dev_pm_ops swrm_dev_pm_ops = {
> + SET_RUNTIME_PM_OPS(swrm_runtime_suspend, swrm_runtime_resume, NULL)
> +};
> +
> static const struct of_device_id qcom_swrm_of_match[] = {
> { .compatible = "qcom,soundwire-v1.3.0", .data = &swrm_v1_3_data },
> { .compatible = "qcom,soundwire-v1.5.1", .data = &swrm_v1_5_data },
> @@ -1359,6 +1512,7 @@ static struct platform_driver qcom_swrm_driver = {
> .driver = {
> .name = "qcom-soundwire",
> .of_match_table = qcom_swrm_of_match,
> + .pm = &swrm_dev_pm_ops,
> }
> };
> module_platform_driver(qcom_swrm_driver);
