[PATCH v3 7/7] ufs: use PM OPP when scaling gears

From: Krzysztof Kozlowski
Date: Fri May 13 2022 - 02:15:28 EST

Scaling gears requires not only scaling clocks, but also voltage levels,
e.g. via performance states.

Use the provided OPP table, to set proper OPP frequency which through
required-opps will trigger performance state change. This deprecates
the old freq-table-hz Devicetree property and old clock scaling method
in favor of PM core code.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>

---

Cc: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd-pltfrm.c | 73 +++++++++++++++
drivers/scsi/ufs/ufshcd.c | 150 ++++++++++++++++++++++++-------
drivers/scsi/ufs/ufshcd.h | 6 ++
3 files changed, 195 insertions(+), 34 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
index 3ab555f6e66e..a603ca8e383b 100644
--- a/drivers/scsi/ufs/ufshcd-pltfrm.c
+++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
@@ -10,6 +10,7 @@

#include <linux/module.h>
#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>

@@ -108,6 +109,72 @@ static int ufshcd_parse_clock_info(struct ufs_hba *hba)
return ret;
}

+static int ufshcd_parse_operating_points(struct ufs_hba *hba)
+{
+ struct device *dev = hba->dev;
+ struct device_node *np = dev->of_node;
+ struct ufs_clk_info *clki;
+ const char *names[16];
+ int cnt, i, ret;
+
+ if (!of_find_property(dev->of_node, "operating-points-v2", NULL))
+ return 0;
+
+ cnt = of_property_count_strings(np, "clock-names");
+ if (cnt <= 0) {
+ dev_warn(dev, "%s: Missing clock-names\n",
+ __func__);
+ return -EINVAL;
+ }
+
+ if (cnt > ARRAY_SIZE(names)) {
+ dev_info(dev, "%s: Too many clock-names\n", __func__);
+ return -EINVAL;
+ }
+
+ if (of_find_property(np, "freq-table-hz", NULL)) {
+ dev_info(dev, "%s: operating-points and freq-table-hz are incompatible\n",
+ __func__);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < cnt; i++) {
+ ret = of_property_read_string_index(np, "clock-names", i,
+ &names[i]);
+ if (ret)
+ return ret;
+
+ clki = devm_kzalloc(dev, sizeof(*clki), GFP_KERNEL);
+ if (!clki)
+ return -ENOMEM;
+
+ clki->name = devm_kstrdup(dev, names[i], GFP_KERNEL);
+ if (!clki->name)
+ return -ENOMEM;
+
+ if (!strcmp(names[i], "ref_clk"))
+ clki->keep_link_active = true;
+
+ list_add_tail(&clki->list, &hba->clk_list_head);
+ }
+
+ ret = devm_pm_opp_set_clknames(dev, names, i);
+ if (ret)
+ return ret;
+
+ ret = devm_pm_opp_register_set_opp_helper(dev, ufshcd_set_opp);
+ if (ret)
+ return ret;
+
+ ret = devm_pm_opp_of_add_table(dev);
+ if (ret)
+ return ret;
+
+ hba->use_pm_opp = true;
+
+ return 0;
+}
+
#define MAX_PROP_SIZE 32
static int ufshcd_populate_vreg(struct device *dev, const char *name,
struct ufs_vreg **out_vreg)
@@ -363,6 +430,12 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
goto dealloc_host;
}

+ err = ufshcd_parse_operating_points(hba);
+ if (err) {
+ dev_err(dev, "%s: OPP parse failed %d\n", __func__, err);
+ goto dealloc_host;
+ }
+
ufshcd_init_lanes_per_dir(hba);

err = ufshcd_init(hba, mmio_base, irq);
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index ea43aa2d26e1..9f07c4fd0087 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -20,6 +20,7 @@
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/module.h>
+#include <linux/pm_opp.h>
#include <linux/regulator/consumer.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
@@ -259,7 +260,8 @@ 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 void __ufshcd_suspend_clkscaling(struct ufs_hba *hba);
-static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up);
+static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up,
+ unsigned long freq);
static irqreturn_t ufshcd_intr(int irq, void *__hba);
static int ufshcd_change_power_mode(struct ufs_hba *hba,
struct ufs_pa_layer_attr *pwr_mode);
@@ -962,7 +964,7 @@ static bool ufshcd_is_unipro_pa_params_tuning_req(struct ufs_hba *hba)
}

/**
- * ufshcd_set_clk_freq - set UFS controller clock frequencies
+ * ufshcd_set_clk_freq - set UFS controller clock frequencies (directly)
* @hba: per adapter instance
* @scale_up: If True, set max possible frequency othewise set low frequency
*
@@ -1024,15 +1026,48 @@ static int ufshcd_set_clk_freq(struct ufs_hba *hba, bool scale_up)
return ret;
}

+/**
+ * ufshcd_set_opp - scale UFS controller clocks, called via PM OPP
+ * @data: PM OPP data
+ *
+ * Returns 0 for success, non-zero error value for errors.
+ */
+int ufshcd_set_opp(struct dev_pm_set_opp_data *data)
+{
+ struct ufs_hba *hba = dev_get_drvdata(data->dev);
+ int i, ret;
+
+ if (!data->clk_count)
+ return 0;
+
+ for (i = 0; i < data->clk_count; i++) {
+ if (!data->new_opp.rates[i])
+ continue;
+
+ ret = clk_set_rate(data->clks[i].clk, data->new_opp.rates[i]);
+ if (ret) {
+ dev_err(hba->dev, "%s: %pC clk set rate(%luHz) failed, %d\n",
+ __func__, data->clks[i].clk,
+ data->new_opp.rates[i], ret);
+ break;
+ }
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(ufshcd_set_opp);
+
/**
* ufshcd_scale_clks - scale up or scale down UFS controller clocks
* @hba: per adapter instance
* @scale_up: True if scaling up and false if scaling down
+ * @freq: Target frequency
*
* Returns 0 if successful
* Returns < 0 for any other errors
*/
-static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
+static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up,
+ unsigned long freq)
{
int ret = 0;
ktime_t start = ktime_get();
@@ -1041,13 +1076,21 @@ static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
if (ret)
goto out;

- ret = ufshcd_set_clk_freq(hba, scale_up);
+ if (hba->use_pm_opp)
+ ret = dev_pm_opp_set_rate(hba->dev, freq);
+ else
+ ret = ufshcd_set_clk_freq(hba, scale_up);
if (ret)
goto out;

ret = ufshcd_vops_clk_scale_notify(hba, scale_up, POST_CHANGE);
- if (ret)
- ufshcd_set_clk_freq(hba, !scale_up);
+ if (ret) {
+ if (hba->use_pm_opp)
+ dev_pm_opp_set_rate(hba->dev,
+ hba->devfreq->previous_freq);
+ else
+ ufshcd_set_clk_freq(hba, !scale_up);
+ }

out:
trace_ufshcd_profile_clk_scaling(dev_name(hba->dev),
@@ -1059,11 +1102,13 @@ static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
/**
* ufshcd_is_devfreq_scaling_required - check if scaling is required or not
* @hba: per adapter instance
+ * @freq: Target frequency
* @scale_up: True if scaling up and false if scaling down
*
* Returns true if scaling is required, false otherwise.
*/
static bool ufshcd_is_devfreq_scaling_required(struct ufs_hba *hba,
+ unsigned long freq,
bool scale_up)
{
struct ufs_clk_info *clki;
@@ -1072,6 +1117,9 @@ static bool ufshcd_is_devfreq_scaling_required(struct ufs_hba *hba,
if (list_empty(head))
return false;

+ if (hba->use_pm_opp)
+ return freq != hba->clk_scaling.target_freq;
+
list_for_each_entry(clki, head, list) {
if (!IS_ERR_OR_NULL(clki->clk)) {
if (scale_up && clki->max_freq) {
@@ -1251,13 +1299,15 @@ static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba, bool writelock)
/**
* ufshcd_devfreq_scale - scale up/down UFS clocks and gear
* @hba: per adapter instance
+ * @freq: Target frequency
* @scale_up: True for scaling up and false for scalin down
*
* Returns 0 for success,
* Returns -EBUSY if scaling can't happen at this time
* Returns non-zero for any other errors
*/
-static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
+static int ufshcd_devfreq_scale(struct ufs_hba *hba, unsigned long freq,
+ bool scale_up)
{
int ret = 0;
bool is_writelock = true;
@@ -1273,7 +1323,7 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
goto out_unprepare;
}

- ret = ufshcd_scale_clks(hba, scale_up);
+ ret = ufshcd_scale_clks(hba, scale_up, freq);
if (ret) {
if (!scale_up)
ufshcd_scale_gear(hba, true);
@@ -1284,7 +1334,8 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
if (scale_up) {
ret = ufshcd_scale_gear(hba, true);
if (ret) {
- ufshcd_scale_clks(hba, false);
+ ufshcd_scale_clks(hba, false,
+ hba->devfreq->previous_freq);
goto out_unprepare;
}
}
@@ -1347,9 +1398,20 @@ static int ufshcd_devfreq_target(struct device *dev,
if (!ufshcd_is_clkscaling_supported(hba))
return -EINVAL;

- clki = list_first_entry(&hba->clk_list_head, struct ufs_clk_info, list);
/* Override with the closest supported frequency */
- *freq = (unsigned long) clk_round_rate(clki->clk, *freq);
+ if (hba->use_pm_opp) {
+ struct dev_pm_opp *opp;
+
+ opp = devfreq_recommended_opp(dev, freq, flags);
+ if (IS_ERR(opp))
+ return PTR_ERR(opp);
+ dev_pm_opp_put(opp);
+ } else {
+ clki = list_first_entry(&hba->clk_list_head, struct ufs_clk_info,
+ list);
+ *freq = (unsigned long) clk_round_rate(clki->clk, *freq);
+ }
+
spin_lock_irqsave(hba->host->host_lock, irq_flags);
if (ufshcd_eh_in_progress(hba)) {
spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
@@ -1365,11 +1427,11 @@ static int ufshcd_devfreq_target(struct device *dev,
}

/* Decide based on the rounded-off frequency and update */
- scale_up = *freq == clki->max_freq;
- if (!scale_up)
+ scale_up = (*freq > hba->clk_scaling.target_freq);
+ if (!hba->use_pm_opp && !scale_up)
*freq = clki->min_freq;
/* Update the frequency */
- if (!ufshcd_is_devfreq_scaling_required(hba, scale_up)) {
+ if (!ufshcd_is_devfreq_scaling_required(hba, *freq, scale_up)) {
spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
ret = 0;
goto out; /* no state change required */
@@ -1377,7 +1439,9 @@ static int ufshcd_devfreq_target(struct device *dev,
spin_unlock_irqrestore(hba->host->host_lock, irq_flags);

start = ktime_get();
- ret = ufshcd_devfreq_scale(hba, scale_up);
+ ret = ufshcd_devfreq_scale(hba, *freq, scale_up);
+ if (!ret)
+ hba->clk_scaling.target_freq = *freq;

trace_ufshcd_profile_clk_scaling(dev_name(hba->dev),
(scale_up ? "up" : "down"),
@@ -1397,8 +1461,6 @@ static int ufshcd_devfreq_get_dev_status(struct device *dev,
struct ufs_hba *hba = dev_get_drvdata(dev);
struct ufs_clk_scaling *scaling = &hba->clk_scaling;
unsigned long flags;
- struct list_head *clk_list = &hba->clk_list_head;
- struct ufs_clk_info *clki;
ktime_t curr_t;

if (!ufshcd_is_clkscaling_supported(hba))
@@ -1411,13 +1473,20 @@ static int ufshcd_devfreq_get_dev_status(struct device *dev,
if (!scaling->window_start_t)
goto start_window;

- clki = list_first_entry(clk_list, struct ufs_clk_info, list);
- /*
- * If current frequency is 0, then the ondemand governor considers
- * there's no initial frequency set. And it always requests to set
- * to max. frequency.
- */
- stat->current_frequency = clki->curr_freq;
+ if (hba->use_pm_opp) {
+ stat->current_frequency = hba->clk_scaling.target_freq;
+ } else {
+ struct list_head *clk_list = &hba->clk_list_head;
+ struct ufs_clk_info *clki;
+
+ clki = list_first_entry(clk_list, struct ufs_clk_info, list);
+ /*
+ * If current frequency is 0, then the ondemand governor considers
+ * there's no initial frequency set. And it always requests to set
+ * to max. frequency.
+ */
+ stat->current_frequency = clki->curr_freq;
+ }
if (scaling->is_busy_started)
scaling->tot_busy_t += ktime_us_delta(curr_t,
scaling->busy_start_t);
@@ -1450,9 +1519,11 @@ static int ufshcd_devfreq_init(struct ufs_hba *hba)
if (list_empty(clk_list))
return 0;

- clki = list_first_entry(clk_list, struct ufs_clk_info, list);
- dev_pm_opp_add(hba->dev, clki->min_freq, 0);
- dev_pm_opp_add(hba->dev, clki->max_freq, 0);
+ if (!hba->use_pm_opp) {
+ clki = list_first_entry(clk_list, struct ufs_clk_info, list);
+ dev_pm_opp_add(hba->dev, clki->min_freq, 0);
+ dev_pm_opp_add(hba->dev, clki->max_freq, 0);
+ }

ufshcd_vops_config_scaling_param(hba, &hba->vps->devfreq_profile,
&hba->vps->ondemand_data);
@@ -1464,8 +1535,10 @@ static int ufshcd_devfreq_init(struct ufs_hba *hba)
ret = PTR_ERR(devfreq);
dev_err(hba->dev, "Unable to register with devfreq %d\n", ret);

- dev_pm_opp_remove(hba->dev, clki->min_freq);
- dev_pm_opp_remove(hba->dev, clki->max_freq);
+ if (!hba->use_pm_opp) {
+ dev_pm_opp_remove(hba->dev, clki->min_freq);
+ dev_pm_opp_remove(hba->dev, clki->max_freq);
+ }
return ret;
}

@@ -1477,7 +1550,6 @@ static int ufshcd_devfreq_init(struct ufs_hba *hba)
static void ufshcd_devfreq_remove(struct ufs_hba *hba)
{
struct list_head *clk_list = &hba->clk_list_head;
- struct ufs_clk_info *clki;

if (!hba->devfreq)
return;
@@ -1485,9 +1557,13 @@ static void ufshcd_devfreq_remove(struct ufs_hba *hba)
devfreq_remove_device(hba->devfreq);
hba->devfreq = NULL;

- clki = list_first_entry(clk_list, struct ufs_clk_info, list);
- dev_pm_opp_remove(hba->dev, clki->min_freq);
- dev_pm_opp_remove(hba->dev, clki->max_freq);
+ if (!hba->use_pm_opp) {
+ struct ufs_clk_info *clki;
+
+ clki = list_first_entry(clk_list, struct ufs_clk_info, list);
+ dev_pm_opp_remove(hba->dev, clki->min_freq);
+ dev_pm_opp_remove(hba->dev, clki->max_freq);
+ }
}

static void __ufshcd_suspend_clkscaling(struct ufs_hba *hba)
@@ -1571,8 +1647,14 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
if (value) {
ufshcd_resume_clkscaling(hba);
} else {
+ struct dev_pm_opp *opp;
+ unsigned long freq = ULONG_MAX;
+
+ opp = dev_pm_opp_find_freq_floor(dev, &freq);
+ dev_pm_opp_put(opp);
+
ufshcd_suspend_clkscaling(hba);
- err = ufshcd_devfreq_scale(hba, true);
+ err = ufshcd_devfreq_scale(hba, freq, true);
if (err)
dev_err(hba->dev, "%s: failed to scale clocks up %d\n",
__func__, err);
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 0b8d0192f069..6962d36e6c65 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -400,6 +400,7 @@ struct ufs_saved_pwr_info {
* @is_initialized: Indicates whether clock scaling is initialized or not
* @is_busy_started: tracks if busy period has started or not
* @is_suspended: tracks if devfreq is suspended or not
+ * @target_freq: frequency requested by devfreq framework
*/
struct ufs_clk_scaling {
int active_reqs;
@@ -417,6 +418,7 @@ struct ufs_clk_scaling {
bool is_initialized;
bool is_busy_started;
bool is_suspended;
+ unsigned long target_freq;
};

#define UFS_EVENT_HIST_LENGTH 8
@@ -771,6 +773,8 @@ struct ufs_hba_monitor {
* @auto_bkops_enabled: to track whether bkops is enabled in device
* @vreg_info: UFS device voltage regulator information
* @clk_list_head: UFS host controller clocks list node head
+ * @use_pm_opp: whether OPP table is provided and scaling gears should trigger
+ * setting OPP
* @req_abort_count: number of times ufshcd_abort() has been called
* @lanes_per_direction: number of lanes per data direction between the UFS
* controller and the UFS device.
@@ -906,6 +910,7 @@ struct ufs_hba {
bool auto_bkops_enabled;
struct ufs_vreg_info vreg_info;
struct list_head clk_list_head;
+ bool use_pm_opp;

/* Number of requests aborts */
int req_abort_count;
@@ -1037,6 +1042,7 @@ void ufshcd_remove(struct ufs_hba *);
int ufshcd_uic_hibern8_enter(struct ufs_hba *hba);
int ufshcd_uic_hibern8_exit(struct ufs_hba *hba);
void ufshcd_delay_us(unsigned long us, unsigned long tolerance);
+int ufshcd_set_opp(struct dev_pm_set_opp_data *data);
void ufshcd_parse_dev_ref_clk_freq(struct ufs_hba *hba, struct clk *refclk);
void ufshcd_update_evt_hist(struct ufs_hba *hba, u32 id, u32 val);
void ufshcd_hba_stop(struct ufs_hba *hba);
--
2.32.0