From fcb0c4b08a18fe35c3adc594d3edc8e335ff7960 Mon Sep 17 00:00:00 2001 From: Sahitya Tummala Date: Thu, 22 Dec 2016 18:40:50 -0800 Subject: [PATCH] scsi: ufs: Add sysfs node to dynamically control clock scaling Provide an option to enable/disable clock scaling during runtime. Write 1/0 to "clkscale_enable" sysfs node to enable/disable clock scaling. Signed-off-by: Sahitya Tummala Signed-off-by: Subhash Jadavani Signed-off-by: Martin K. Petersen --- drivers/scsi/ufs/ufshcd.c | 95 ++++++++++++++++++++++++++++++++------- drivers/scsi/ufs/ufshcd.h | 4 +- 2 files changed, 82 insertions(+), 17 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 0da9e16317f5..4468ba059696 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -230,6 +230,9 @@ static int ufshcd_uic_hibern8_exit(struct ufs_hba *hba); static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba); static inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba *hba); static int ufshcd_host_reset_and_restore(struct ufs_hba *hba); +static void ufshcd_resume_clkscaling(struct ufs_hba *hba); +static void ufshcd_suspend_clkscaling(struct ufs_hba *hba); +static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up); static irqreturn_t ufshcd_intr(int irq, void *__hba); static int ufshcd_config_pwr_mode(struct ufs_hba *hba, struct ufs_pa_layer_attr *desired_pwr_mode); @@ -713,16 +716,58 @@ static bool ufshcd_is_unipro_pa_params_tuning_req(struct ufs_hba *hba) static void ufshcd_suspend_clkscaling(struct ufs_hba *hba) { - if (ufshcd_is_clkscaling_enabled(hba)) { - devfreq_suspend_device(hba->devfreq); - hba->clk_scaling.window_start_t = 0; - } + if (!ufshcd_is_clkscaling_supported(hba)) + return; + + devfreq_suspend_device(hba->devfreq); + hba->clk_scaling.window_start_t = 0; } static void ufshcd_resume_clkscaling(struct ufs_hba *hba) { - if (ufshcd_is_clkscaling_enabled(hba)) - devfreq_resume_device(hba->devfreq); + devfreq_resume_device(hba->devfreq); +} + +static ssize_t ufshcd_clkscale_enable_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct ufs_hba *hba = dev_get_drvdata(dev); + + return snprintf(buf, PAGE_SIZE, "%d\n", hba->clk_scaling.is_allowed); +} + +static ssize_t ufshcd_clkscale_enable_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct ufs_hba *hba = dev_get_drvdata(dev); + u32 value; + int err; + + if (kstrtou32(buf, 0, &value)) + return -EINVAL; + + value = !!value; + if (value == hba->clk_scaling.is_allowed) + goto out; + + pm_runtime_get_sync(hba->dev); + ufshcd_hold(hba, false); + + if (value) { + ufshcd_resume_clkscaling(hba); + } else { + ufshcd_suspend_clkscaling(hba); + err = ufshcd_scale_clks(hba, true); + if (err) + dev_err(hba->dev, "%s: failed to scale clocks up %d\n", + __func__, err); + } + hba->clk_scaling.is_allowed = value; + + ufshcd_release(hba); + pm_runtime_put_sync(hba->dev); +out: + return count; } static void ufshcd_ungate_work(struct work_struct *work) @@ -758,7 +803,8 @@ static void ufshcd_ungate_work(struct work_struct *work) hba->clk_gating.is_suspended = false; } unblock_reqs: - ufshcd_resume_clkscaling(hba); + if (hba->clk_scaling.is_allowed) + ufshcd_resume_clkscaling(hba); scsi_unblock_requests(hba->host); } @@ -1046,7 +1092,7 @@ static void ufshcd_exit_clk_gating(struct ufs_hba *hba) /* Must be called with host lock acquired */ static void ufshcd_clk_scaling_start_busy(struct ufs_hba *hba) { - if (!ufshcd_is_clkscaling_enabled(hba)) + if (!ufshcd_is_clkscaling_supported(hba)) return; if (!hba->clk_scaling.is_busy_started) { @@ -1059,7 +1105,7 @@ static void ufshcd_clk_scaling_update_busy(struct ufs_hba *hba) { struct ufs_clk_scaling *scaling = &hba->clk_scaling; - if (!ufshcd_is_clkscaling_enabled(hba)) + if (!ufshcd_is_clkscaling_supported(hba)) return; if (!hba->outstanding_reqs && scaling->is_busy_started) { @@ -5526,12 +5572,15 @@ static int ufshcd_probe_hba(struct ufs_hba *hba) pm_runtime_put_sync(hba->dev); } + /* Resume devfreq after UFS device is detected */ + if (ufshcd_is_clkscaling_supported(hba)) { + ufshcd_resume_clkscaling(hba); + hba->clk_scaling.is_allowed = true; + } + if (!hba->is_init_prefetch) hba->is_init_prefetch = true; - /* Resume devfreq after UFS device is detected */ - ufshcd_resume_clkscaling(hba); - out: /* * If we failed to initialize the device or the device is not @@ -6484,7 +6533,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op) ufshcd_urgent_bkops(hba); hba->clk_gating.is_suspended = false; - ufshcd_resume_clkscaling(hba); + if (hba->clk_scaling.is_allowed) + ufshcd_resume_clkscaling(hba); /* Schedule clock gating in case of no access to UFS device yet */ ufshcd_release(hba); @@ -6702,6 +6752,8 @@ void ufshcd_remove(struct ufs_hba *hba) ufshcd_hba_stop(hba, true); ufshcd_exit_clk_gating(hba); + if (ufshcd_is_clkscaling_supported(hba)) + device_remove_file(hba->dev, &hba->clk_scaling.enable_attr); ufshcd_hba_exit(hba); } EXPORT_SYMBOL_GPL(ufshcd_remove); @@ -6835,7 +6887,7 @@ static int ufshcd_devfreq_target(struct device *dev, bool release_clk_hold = false; unsigned long irq_flags; - if (!ufshcd_is_clkscaling_enabled(hba)) + if (!ufshcd_is_clkscaling_supported(hba)) return -EINVAL; spin_lock_irqsave(hba->host->host_lock, irq_flags); @@ -6883,7 +6935,7 @@ static int ufshcd_devfreq_get_dev_status(struct device *dev, struct ufs_clk_scaling *scaling = &hba->clk_scaling; unsigned long flags; - if (!ufshcd_is_clkscaling_enabled(hba)) + if (!ufshcd_is_clkscaling_supported(hba)) return -EINVAL; memset(stat, 0, sizeof(*stat)); @@ -6919,6 +6971,16 @@ static struct devfreq_dev_profile ufs_devfreq_profile = { .target = ufshcd_devfreq_target, .get_dev_status = ufshcd_devfreq_get_dev_status, }; +static void ufshcd_clkscaling_init_sysfs(struct ufs_hba *hba) +{ + hba->clk_scaling.enable_attr.show = ufshcd_clkscale_enable_show; + hba->clk_scaling.enable_attr.store = ufshcd_clkscale_enable_store; + sysfs_attr_init(&hba->clk_scaling.enable_attr.attr); + hba->clk_scaling.enable_attr.attr.name = "clkscale_enable"; + hba->clk_scaling.enable_attr.attr.mode = 0644; + if (device_create_file(hba->dev, &hba->clk_scaling.enable_attr)) + dev_err(hba->dev, "Failed to create sysfs for clkscale_enable\n"); +} /** * ufshcd_init - Driver initialization routine @@ -7045,7 +7107,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) goto out_remove_scsi_host; } - if (ufshcd_is_clkscaling_enabled(hba)) { + if (ufshcd_is_clkscaling_supported(hba)) { hba->devfreq = devm_devfreq_add_device(dev, &ufs_devfreq_profile, "simple_ondemand", NULL); if (IS_ERR(hba->devfreq)) { @@ -7056,6 +7118,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) } /* Suspend devfreq until the UFS device is detected */ ufshcd_suspend_clkscaling(hba); + ufshcd_clkscaling_init_sysfs(hba); } /* Hold auto suspend until async scan completes */ diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index 0882ba67ccb1..bdd2284967f2 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -342,6 +342,8 @@ struct ufs_clk_scaling { bool is_busy_started; unsigned long tot_busy_t; unsigned long window_start_t; + struct device_attribute enable_attr; + bool is_allowed; }; /** @@ -580,7 +582,7 @@ static inline bool ufshcd_can_hibern8_during_gating(struct ufs_hba *hba) { return hba->caps & UFSHCD_CAP_HIBERN8_WITH_CLK_GATING; } -static inline int ufshcd_is_clkscaling_enabled(struct ufs_hba *hba) +static inline int ufshcd_is_clkscaling_supported(struct ufs_hba *hba) { return hba->caps & UFSHCD_CAP_CLK_SCALING; } -- 2.20.1