Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 63b08df3 authored by Sahitya Tummala's avatar Sahitya Tummala
Browse files

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.

Change-Id: I67a6cd317d3dca97a992e240c970719f85067cd8
Signed-off-by: default avatarSahitya Tummala <stummala@codeaurora.org>
parent 2e75a292

drivers/scsi/ufs/ufshcd.c

+88 −22
Original line number Diff line number Diff line
@@ -278,6 +278,8 @@ static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on); 
static int ufshcd_uic_hibern8_exit(struct ufs_hba *hba);

static int ufshcd_uic_hibern8_enter(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 inline void ufshcd_enable_irq(struct ufs_hba *hba)

{
@@ -758,8 +760,8 @@ static void ufshcd_ungate_work(struct work_struct *work) 
		hba->clk_gating.is_suspended = false;

	}

unblock_reqs:

	if (ufshcd_is_clkscaling_enabled(hba))

		devfreq_resume_device(hba->devfreq);

	if (hba->clk_scaling.is_allowed)

		ufshcd_resume_clkscaling(hba);

	scsi_unblock_requests(hba->host);

}
@@ -864,10 +866,7 @@ static void ufshcd_gate_work(struct work_struct *work) 
		ufshcd_set_link_hibern8(hba);

	}



	if (ufshcd_is_clkscaling_enabled(hba)) {

		devfreq_suspend_device(hba->devfreq);

		hba->clk_scaling.window_start_t = 0;

	}

	ufshcd_suspend_clkscaling(hba);



	if (!ufshcd_is_link_active(hba))

		ufshcd_setup_clocks(hba, false);
@@ -1025,7 +1024,7 @@ 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) {
@@ -1038,7 +1037,7 @@ 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) {
@@ -4744,8 +4743,10 @@ 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_enabled(hba))

		devfreq_resume_device(hba->devfreq);

	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;

out:
@@ -5689,10 +5690,7 @@ disable_clks: 
	 * for pending clock scaling work to be done before clocks are

	 * turned off.

	 */

	if (ufshcd_is_clkscaling_enabled(hba)) {

		devfreq_suspend_device(hba->devfreq);

		hba->clk_scaling.window_start_t = 0;

	}

	ufshcd_suspend_clkscaling(hba);

	/*

	 * Call vendor specific suspend callback. As these callbacks may access

	 * vendor specific host controller register space call them before the
@@ -5818,8 +5816,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op) 
	ufshcd_disable_auto_bkops(hba);

	hba->clk_gating.is_suspended = false;



	if (ufshcd_is_clkscaling_enabled(hba))

		devfreq_resume_device(hba->devfreq);

	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);
@@ -6039,8 +6037,10 @@ void ufshcd_remove(struct ufs_hba *hba) 
	ufshcd_hba_stop(hba, true);



	ufshcd_exit_clk_gating(hba);

	if (ufshcd_is_clkscaling_enabled(hba))

	if (ufshcd_is_clkscaling_supported(hba)) {

		device_remove_file(hba->dev, &hba->clk_scaling.enable_attr);

		devfreq_remove_device(hba->devfreq);

	}

	ufshcd_hba_exit(hba);

}

EXPORT_SYMBOL_GPL(ufshcd_remove);
@@ -6168,13 +6168,69 @@ out: 
	return ret;

}



static void ufshcd_suspend_clkscaling(struct ufs_hba *hba)

{

	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)

{

	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 int ufshcd_devfreq_target(struct device *dev,

				unsigned long *freq, u32 flags)

{

	int err = 0;

	struct ufs_hba *hba = dev_get_drvdata(dev);



	if (!ufshcd_is_clkscaling_enabled(hba))

	if (!ufshcd_is_clkscaling_supported(hba))

		return -EINVAL;



	if (*freq == UINT_MAX)
@@ -6192,7 +6248,7 @@ 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));
@@ -6244,6 +6300,16 @@ static struct devfreq_dev_profile ufs_devfreq_profile = { 
	.num_governor_data = ARRAY_SIZE(ufshcd_governors),

#endif

};

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 = S_IRUGO | S_IWUSR;

	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
@@ -6354,7 +6420,7 @@ 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 = devfreq_add_device(dev, &ufs_devfreq_profile,

						   "simple_ondemand", NULL);

		if (IS_ERR(hba->devfreq)) {
@@ -6363,8 +6429,8 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) 
			goto out_remove_scsi_host;

		}

		/* Suspend devfreq until the UFS device is detected */

		devfreq_suspend_device(hba->devfreq);

		hba->clk_scaling.window_start_t = 0;

		ufshcd_suspend_clkscaling(hba);

		ufshcd_clkscaling_init_sysfs(hba);

	}



	/*

drivers/scsi/ufs/ufshcd.h

+3 −1
Original line number Diff line number Diff line
@@ -366,6 +366,8 @@ 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;

};



/**
@@ -572,7 +574,7 @@ 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;

}