From: Sahitya Tummala <stumm...@codeaurora.org>
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 <stumm...@codeaurora.org>
Signed-off-by: Subhash Jadavani <subha...@codeaurora.org>
---
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 ccf54c1..3fa3ca3 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -230,6 +230,9 @@ static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool
on,
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 const char *ufschd_uic_link_state_to_string(
@@ -792,7 +837,8 @@ 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);
}
@@ -1087,7 +1133,7 @@ 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) {
@@ -1100,7 +1146,7 @@ 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) {
@@ -5567,12 +5613,15 @@ 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
@@ -6528,7 +6577,8 @@ 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);
@@ -6750,6 +6800,8 @@ 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);
@@ -6883,7 +6935,7 @@ 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);
@@ -6931,7 +6983,7 @@ 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));
@@ -6967,6 +7019,16 @@ static int ufshcd_devfreq_get_dev_status(struct device
*dev,
.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
@@ -7093,7 +7155,7 @@ 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)) {
@@ -7104,6 +7166,7 @@ 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 0882ba6..bdd2284 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;
}
--
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