scsi: ufs: Use freq table with devfreq

devfreq requires that the client operates on actual frequencies, not only 0
and UMAX_INT and as such UFS brok with the introduction of f1d981eaecf8 ("PM
/ devfreq: Use the available min/max frequency").

This patch registers the frequencies of the first clock with devfreq and use
these to determine if we're trying to step up or down.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> [for devfreq & OPP part]
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c21c9bd..892ad43 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1183,16 +1183,13 @@ static int ufshcd_devfreq_target(struct device *dev,
        struct ufs_hba *hba = dev_get_drvdata(dev);
        ktime_t start;
        bool scale_up, sched_clk_scaling_suspend_work = false;
+       struct list_head *clk_list = &hba->clk_list_head;
+       struct ufs_clk_info *clki;
        unsigned long irq_flags;
 
        if (!ufshcd_is_clkscaling_supported(hba))
                return -EINVAL;
 
-       if ((*freq > 0) && (*freq < UINT_MAX)) {
-               dev_err(hba->dev, "%s: invalid freq = %lu\n", __func__, *freq);
-               return -EINVAL;
-       }
-
        spin_lock_irqsave(hba->host->host_lock, irq_flags);
        if (ufshcd_eh_in_progress(hba)) {
                spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
@@ -1202,7 +1199,13 @@ static int ufshcd_devfreq_target(struct device *dev,
        if (!hba->clk_scaling.active_reqs)
                sched_clk_scaling_suspend_work = true;
 
-       scale_up = (*freq == UINT_MAX) ? true : false;
+       if (list_empty(clk_list)) {
+               spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
+               goto out;
+       }
+
+       clki = list_first_entry(&hba->clk_list_head, struct ufs_clk_info, list);
+       scale_up = (*freq == clki->max_freq) ? true : false;
        if (!ufshcd_is_devfreq_scaling_required(hba, scale_up)) {
                spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
                ret = 0;
@@ -1272,16 +1275,29 @@ static struct devfreq_dev_profile ufs_devfreq_profile = {
 
 static int ufshcd_devfreq_init(struct ufs_hba *hba)
 {
+       struct list_head *clk_list = &hba->clk_list_head;
+       struct ufs_clk_info *clki;
        struct devfreq *devfreq;
        int ret;
 
-       devfreq = devm_devfreq_add_device(hba->dev,
+       /* Skip devfreq if we don't have any clocks in the list */
+       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);
+
+       devfreq = devfreq_add_device(hba->dev,
                        &ufs_devfreq_profile,
                        DEVFREQ_GOV_SIMPLE_ONDEMAND,
                        NULL);
        if (IS_ERR(devfreq)) {
                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);
                return ret;
        }
 
@@ -1290,6 +1306,22 @@ static int ufshcd_devfreq_init(struct ufs_hba *hba)
        return 0;
 }
 
+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;
+
+       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);
+}
+
 static void __ufshcd_suspend_clkscaling(struct ufs_hba *hba)
 {
        unsigned long flags;
@@ -7071,6 +7103,7 @@ static void ufshcd_hba_exit(struct ufs_hba *hba)
                        if (hba->devfreq)
                                ufshcd_suspend_clkscaling(hba);
                        destroy_workqueue(hba->clk_scaling.workq);
+                       ufshcd_devfreq_remove(hba);
                }
                ufshcd_setup_clocks(hba, false);
                ufshcd_setup_hba_vreg(hba, false);