From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sagar Dharia Subject: [PATCH V3 6/6] slim: qcom: Add runtime-pm support using clock-pause feature Date: Mon, 3 Aug 2015 00:59:50 -0600 Message-ID: <1438585190-11894-7-git-send-email-sdharia@codeaurora.org> References: <1438585190-11894-1-git-send-email-sdharia@codeaurora.org> Return-path: In-Reply-To: <1438585190-11894-1-git-send-email-sdharia@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: gregkh@linuxfoundation.org, bp@suse.de, poeschel@lemonage.de, sdharia@codeaurora.org, treding@nvidia.com, broonie@kernel.org, gong.chen@linux.intel.com, andreas.noever@gmail.com, alan@linux.intel.com, mathieu.poirier@linaro.org, daniel@ffwll.ch, oded.gabbay@amd.com, jkosina@suse.cz, sharon.dvir1@mail.huji.ac.il, joe@perches.com, davem@davemloft.net, james.hogan@imgtec.com, michael.opdenacker@free-electrons.com, daniel.thompson@linaro.org, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Cc: kheitke@audience.com, mlocke@codeaurora.org, agross@codeaurora.org, linux-arm-msm@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org Slimbus HW mandates that clock-pause sequence has to be executed before disabling relevant interface and core clocks. Runtime-PM's autosuspend feature is used here to enter/exit low power mode for Qualcomm's Slimbus controller. Autosuspend feature enables driver to avoid changing power-modes too frequently since entering clock-pause is an expensive sequence Signed-off-by: Sagar Dharia --- drivers/slimbus/slim-qcom-ctrl.c | 149 ++++++++++++++++++++++++++++++++++++++- drivers/slimbus/slim-qcom.h | 1 + 2 files changed, 149 insertions(+), 1 deletion(-) diff --git a/drivers/slimbus/slim-qcom-ctrl.c b/drivers/slimbus/slim-qcom-ctrl.c index 7ff0536..45023a6 100644 --- a/drivers/slimbus/slim-qcom-ctrl.c +++ b/drivers/slimbus/slim-qcom-ctrl.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "slim-qcom.h" #define MSM_SLIM_NAME "msm_slim_ctrl" @@ -210,6 +211,7 @@ rx_ret_irq: if (q_rx) queue_work(dev->rxwq, &dev->wd); } + pm_runtime_mark_last_busy(dev->dev); /** * All interrupts are handled: complex RX messages requiring more work * are queued to work-queue, others are handled above @@ -237,6 +239,28 @@ static void msm_slim_wait_retry(struct msm_slim_ctrl *dev) msleep(msec_per_frm); } +static int msm_clk_pause_wakeup(struct slim_controller *ctrl) +{ + struct msm_slim_ctrl *dev = slim_get_ctrldata(ctrl); + + clk_prepare_enable(dev->hclk); + clk_prepare_enable(dev->rclk); + writel_relaxed(1, dev->base + FRM_WAKEUP); + /* Make sure framer wakeup write goes through before ISR fires */ + mb(); + /** + * HW Workaround: Currently, slave is reporting lost-sync messages + * after slimbus comes out of clock pause. + * Transaction with slave fail before slave reports that message + * Give some time for that report to come + * Slimbus wakes up in clock gear 10 at 24.576MHz. With each superframe + * being 250 usecs, we wait for 5-10 superframes here to ensure + * we get the message + */ + usleep_range(1250, 2500); + return 0; +} + static int msm_xfer_msg(struct slim_controller *ctrl, struct slim_msg_txn *txn, void *pbuf) { @@ -245,6 +269,22 @@ static int msm_xfer_msg(struct slim_controller *ctrl, struct slim_msg_txn *txn, u32 *head = (u32 *)pbuf; u8 *puc = (u8 *)pbuf; u8 la = txn->la; + enum slim_clk_state cur_clk_state = ctrl->sched.clk_state; + + if (cur_clk_state == SLIM_CLK_ENTERING_PAUSE) { + if (txn->mc != SLIM_MSG_MC_BEGIN_RECONFIGURATION && + txn->mc != SLIM_MSG_MC_RECONFIGURE_NOW && + txn->mc != SLIM_MSG_MC_NEXT_PAUSE_CLOCK) + return -EBUSY; + } else { + int ret = pm_runtime_get_sync(dev->dev); + + if (ret < 0) { + pm_runtime_set_suspended(dev->dev); + dev_err(dev->dev, "runtime-pm vote failed:%d\n", ret); + return ret; + } + } /* HW expects length field to be excluded */ txn->rl--; @@ -273,6 +313,9 @@ static int msm_xfer_msg(struct slim_controller *ctrl, struct slim_msg_txn *txn, if (txn->msg && txn->msg->wbuf) memcpy(puc, txn->msg->wbuf, txn->msg->num_bytes); + if (cur_clk_state != SLIM_CLK_ENTERING_PAUSE) + pm_runtime_put(dev->dev); + return msm_slim_queue_tx(dev, head, txn->rl, MGR_TX_MSG); } @@ -296,13 +339,19 @@ static int msm_set_laddr(struct slim_controller *ctrl, buf[5] = ead->instance; /* Logical address for this EA */ buf[6] = laddr; + + ret = pm_runtime_get_sync(dev->dev); + if (ret < 0) { + pm_runtime_set_suspended(dev->dev); + dev_err(dev->dev, "runtime-pm vote failed:%d\n", ret); + return ret; + } /** * Retries are needed since bus may lose sync when multiple devices * are coming up and reporting present */ msg.wbuf = buf; msg.num_bytes = 7; - retry_laddr: ret = slim_processtxn(&dev->ctrl, &txn); @@ -317,6 +366,7 @@ retry_laddr: dev_err(dev->dev, "set LADDR failed:ret:%d\n", ret); } } + pm_runtime_put(dev->dev); return ret; } @@ -444,6 +494,8 @@ static int msm_slim_probe(struct platform_device *pdev) dev->ctrl.set_laddr = msm_set_laddr; dev->ctrl.xfer_msg = msm_xfer_msg; + dev->ctrl.wakeup = msm_clk_pause_wakeup; + dev->ctrl.tx.n = MSM_TX_MSGS; dev->ctrl.rx.n = MSM_RX_MSGS; dev->ctrl.tx.sl_sz = SLIM_MSGQ_BUF_LEN; @@ -541,6 +593,12 @@ static int msm_slim_probe(struct platform_device *pdev) */ mb(); + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_set_autosuspend_delay(&pdev->dev, MSM_SLIM_AUTOSUSPEND); + pm_runtime_set_active(&pdev->dev); + pm_runtime_mark_last_busy(&pdev->dev); + pm_runtime_enable(&pdev->dev); + dev_dbg(dev->dev, "MSM SB controller is up:ver:0x%x!\n", dev->ver); return 0; @@ -558,11 +616,99 @@ static int msm_slim_remove(struct platform_device *pdev) { struct msm_slim_ctrl *dev = platform_get_drvdata(pdev); + pm_runtime_disable(&pdev->dev); slim_del_controller(&dev->ctrl); destroy_workqueue(dev->rxwq); return 0; } +/** + * If PM_RUNTIME is not defined, these 2 functions become helper + * functions to be called from system suspend/resume. + */ +#ifdef CONFIG_PM +static int msm_slim_runtime_suspend(struct device *device) +{ + struct platform_device *pdev = to_platform_device(device); + struct msm_slim_ctrl *dev = platform_get_drvdata(pdev); + int ret; + + dev_dbg(device, "pm_runtime: suspending...\n"); + ret = slim_ctrl_clk_pause(&dev->ctrl, false, SLIM_CLK_UNSPECIFIED); + if (ret) + dev_err(device, "clk pause not entered:%d", ret); + else { + clk_disable_unprepare(dev->hclk); + clk_disable_unprepare(dev->rclk); + } + return ret; +} + +static int msm_slim_runtime_resume(struct device *device) +{ + struct platform_device *pdev = to_platform_device(device); + struct msm_slim_ctrl *dev = platform_get_drvdata(pdev); + int ret = 0; + + dev_dbg(device, "pm_runtime: resuming...\n"); + ret = slim_ctrl_clk_pause(&dev->ctrl, true, 0); + if (ret) + dev_err(device, "clk pause not exited:%d", ret); + return ret; +} +#endif + +#ifdef CONFIG_PM_SLEEP +static int msm_slim_suspend(struct device *dev) +{ + int ret = 0; + + if (!pm_runtime_enabled(dev) || + (!pm_runtime_suspended(dev))) { + dev_dbg(dev, "system suspend"); + ret = msm_slim_runtime_suspend(dev); + } + if (ret == -EISCONN) { + /** + * If the clock pause failed due to active channels, there is + * a possibility that some audio stream is active during suspend + * We dont want to return suspend failure in that case so that + * display and relevant components can still go to suspend. + * If there is some other error, then it should prevent + * system level suspend + */ + ret = 0; + } + return ret; +} + +static int msm_slim_resume(struct device *dev) +{ + if (!pm_runtime_enabled(dev) || !pm_runtime_suspended(dev)) { + int ret; + + dev_dbg(dev, "system resume"); + ret = msm_slim_runtime_resume(dev); + if (!ret) { + pm_runtime_mark_last_busy(dev); + pm_request_autosuspend(dev); + } + return ret; + + } + return 0; +} +#endif /* CONFIG_PM_SLEEP */ + +static const struct dev_pm_ops msm_slim_dev_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(msm_slim_suspend, msm_slim_resume) + SET_RUNTIME_PM_OPS( + msm_slim_runtime_suspend, + msm_slim_runtime_resume, + NULL + ) +}; + static const struct of_device_id msm_slim_dt_match[] = { { .compatible = "qcom,slim-msm", @@ -577,6 +723,7 @@ static struct platform_driver msm_slim_driver = { .name = MSM_SLIM_NAME, .owner = THIS_MODULE, .of_match_table = msm_slim_dt_match, + .pm = &msm_slim_dev_pm_ops, }, }; module_platform_driver(msm_slim_driver); diff --git a/drivers/slimbus/slim-qcom.h b/drivers/slimbus/slim-qcom.h index 115a8b8..b678c3a 100644 --- a/drivers/slimbus/slim-qcom.h +++ b/drivers/slimbus/slim-qcom.h @@ -25,6 +25,7 @@ #define SLIM_ROOT_FREQ 24576000 #define INIT_MX_RETRIES 10 #define DEF_RETRY_MS 10 +#define MSM_SLIM_AUTOSUSPEND 1000 /* MAX message size over control channel */ #define SLIM_MSGQ_BUF_LEN 40 -- 1.8.2.1