[PATCH v3 2/8] scsi: ufs: qcom: Pass target_freq to clk scale pre and post change

Ziqi Chen
2025-02-03T08:12:47Z

From: Can Guo <quic_cang@quicinc.com>

Instead of only two frequencies, if OPP V2 is used, the UFS devfreq clock
scaling may scale the clock among multiple frequencies. In the case of
scaling up, the devfreq may decide to scale the clock to an intermediate
freq base on load, but the clock scale up pre change operation uses
settings for the max clock freq unconditionally. Fix it by passing the
target_freq to clock scale up pre change so that the correct settings for
the target_freq can be used.

In the case of scaling down, the clock scale down post change operation
is doing fine, because it reads the actual clock rate to tell freq, but to
keep symmetry with clock scale up pre change operation, just use the
target_freq instead of reading clock rate.

Signed-off-by: Can Guo <quic_cang@quicinc.com>
Co-developed-by: Ziqi Chen <quic_ziqichen@quicinc.com>
Signed-off-by: Ziqi Chen <quic_ziqichen@quicinc.com>
---

v1 -> v2:
1. Modify commit message to make it more clear.
2. Use common Macro HZ_PER_MHZ in function ufs_qcom_set_core_clk_ctrl().

v2 -> v3:
Commit message typo fixed.
---
drivers/ufs/host/ufs-qcom.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index b6eef975dc46..a1eb3cab45e4 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -15,6 +15,7 @@
#include <linux/platform_device.h>
#include <linux/reset-controller.h>
#include <linux/time.h>
+#include <linux/units.h>

#include <soc/qcom/ice.h>

@@ -97,7 +98,7 @@ static const struct __ufs_qcom_bw_table {
};

static void ufs_qcom_get_default_testbus_cfg(struct ufs_qcom_host *host);
-static int ufs_qcom_set_core_clk_ctrl(struct ufs_hba *hba, bool is_scale_up);
+static int ufs_qcom_set_core_clk_ctrl(struct ufs_hba *hba, unsigned long freq);

static struct ufs_qcom_host *rcdev_to_ufs_host(struct reset_controller_dev *rcd)
{
@@ -524,7 +525,7 @@ static int ufs_qcom_link_startup_notify(struct ufs_hba *hba,
return -EINVAL;
}

- err = ufs_qcom_set_core_clk_ctrl(hba, true);
+ err = ufs_qcom_set_core_clk_ctrl(hba, ULONG_MAX);
if (err)
dev_err(hba->dev, "cfg core clk ctrl failed\n");
/*
@@ -1231,7 +1232,7 @@ static int ufs_qcom_set_clk_40ns_cycles(struct ufs_hba *hba,
return ufshcd_dme_set(hba, UIC_ARG_MIB(PA_VS_CORE_CLK_40NS_CYCLES), reg);
}

-static int ufs_qcom_set_core_clk_ctrl(struct ufs_hba *hba, bool is_scale_up)
+static int ufs_qcom_set_core_clk_ctrl(struct ufs_hba *hba, unsigned long freq)
{
struct ufs_qcom_host *host = ufshcd_get_variant(hba);
struct list_head *head = &hba->clk_list_head;
@@ -1245,10 +1246,11 @@ static int ufs_qcom_set_core_clk_ctrl(struct ufs_hba *hba, bool is_scale_up)
!strcmp(clki->name, "core_clk_unipro")) {
if (!clki->max_freq)
cycles_in_1us = 150; /* default for backwards compatibility */
- else if (is_scale_up)
- cycles_in_1us = ceil(clki->max_freq, (1000 * 1000));
+ else if (freq == ULONG_MAX)
+ cycles_in_1us = ceil(clki->max_freq, HZ_PER_MHZ);
else
- cycles_in_1us = ceil(clk_get_rate(clki->clk), (1000 * 1000));
+ cycles_in_1us = ceil(freq, HZ_PER_MHZ);
+
break;
}
}
@@ -1285,7 +1287,7 @@ static int ufs_qcom_set_core_clk_ctrl(struct ufs_hba *hba, bool is_scale_up)
return ufs_qcom_set_clk_40ns_cycles(hba, cycles_in_1us);
}

-static int ufs_qcom_clk_scale_up_pre_change(struct ufs_hba *hba)
+static int ufs_qcom_clk_scale_up_pre_change(struct ufs_hba *hba, unsigned long freq)
{
struct ufs_qcom_host *host = ufshcd_get_variant(hba);
struct ufs_pa_layer_attr *attr = &host->dev_req_params;
@@ -1298,7 +1300,7 @@ static int ufs_qcom_clk_scale_up_pre_change(struct ufs_hba *hba)
return ret;
}
/* set unipro core clock attributes and clear clock divider */
- return ufs_qcom_set_core_clk_ctrl(hba, true);
+ return ufs_qcom_set_core_clk_ctrl(hba, freq);
}

static int ufs_qcom_clk_scale_up_post_change(struct ufs_hba *hba)
@@ -1327,10 +1329,10 @@ static int ufs_qcom_clk_scale_down_pre_change(struct ufs_hba *hba)
return err;
}

-static int ufs_qcom_clk_scale_down_post_change(struct ufs_hba *hba)
+static int ufs_qcom_clk_scale_down_post_change(struct ufs_hba *hba, unsigned long freq)
{
/* set unipro core clock attributes and clear clock divider */
- return ufs_qcom_set_core_clk_ctrl(hba, false);
+ return ufs_qcom_set_core_clk_ctrl(hba, freq);
}

static int ufs_qcom_clk_scale_notify(struct ufs_hba *hba, bool scale_up,
@@ -1349,7 +1351,7 @@ static int ufs_qcom_clk_scale_notify(struct ufs_hba *hba, bool scale_up,
if (err)
return err;
if (scale_up)
- err = ufs_qcom_clk_scale_up_pre_change(hba);
+ err = ufs_qcom_clk_scale_up_pre_change(hba, target_freq);
else
err = ufs_qcom_clk_scale_down_pre_change(hba);

@@ -1361,7 +1363,7 @@ static int ufs_qcom_clk_scale_notify(struct ufs_hba *hba, bool scale_up,
if (scale_up)
err = ufs_qcom_clk_scale_up_post_change(hba);
else
- err = ufs_qcom_clk_scale_down_post_change(hba);
+ err = ufs_qcom_clk_scale_down_post_change(hba, target_freq);

if (err) {
--
2.34.1