Re: [PATCH V5 3/6] scsi: ufs: qcom: Add multiple frequency support for unipro clk attributes

From: Manivannan Sadhasivam
Date: Mon Aug 28 2023 - 04:14:33 EST

On Mon, Aug 28, 2023 at 01:35:37PM +0530, Manivannan Sadhasivam wrote:
> On Wed, Aug 23, 2023 at 09:14:10PM +0530, Nitin Rawat wrote:
> > Add Support to configure CORE_CLK_1US_CYCLES, PA_VS_CORE_CLK_40NS_CYCLES
> > for multiple unipro clock frequencies. Currently this is handled only for
> > only 150Mhz and 75MHz.
> >
> > Co-developed-by: Naveen Kumar Goud Arepalli <quic_narepall@xxxxxxxxxxx>
> > Signed-off-by: Naveen Kumar Goud Arepalli <quic_narepall@xxxxxxxxxxx>
> > Signed-off-by: Nitin Rawat <quic_nitirawa@xxxxxxxxxxx>
> > ---
> > drivers/ufs/host/ufs-qcom.c | 88 ++++++++++++++++++++++++++++++++-----
> > drivers/ufs/host/ufs-qcom.h | 9 ++++
> > 2 files changed, 87 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
> > index abc0e7f7d1b0..8162b19191a9 100644
> > --- a/drivers/ufs/host/ufs-qcom.c
> > +++ b/drivers/ufs/host/ufs-qcom.c
> > @@ -671,6 +671,45 @@ static int ufs_qcom_cfg_timers(struct ufs_hba *hba, u32 gear,
> > return 0;
> > }
> >
> > +static int ufs_qcom_cfg_core_clk_ctrl(struct ufs_hba *hba)
> > +{
> > + struct list_head *head = &hba->clk_list_head;
> > + struct ufs_clk_info *clki;
> > + u32 max_freq = 0;
> > + int err;
>
> Let's use "ret" from now onwards. Existing "err" can be cleaned up later.
>
> > +
> > + list_for_each_entry(clki, head, list) {
> > + if (!IS_ERR_OR_NULL(clki->clk) &&
> > + !strcmp(clki->name, "core_clk_unipro")) {
>
> Odd indentation.
>
> > + max_freq = clki->max_freq;
> > + break;
> > + }
> > + }
> > +
> > + switch (max_freq) {
> > + case MHZ_403:
>
> UNIPRO_CORE_CLK_FREQ_403_MHZ?
>
> Same applies to other defines.
>
> > + err = ufs_qcom_set_core_clk_ctrl(hba, 403, 16);
>
> #define to_cycles_per_1us(freq) (freq / (1000 * 1000))
>
> ret = ufs_qcom_set_core_clk_ctrl(hba, to_cycles_per_1us(max_freq), 16);
>

You could also use:

#define to_cycles_per_40us(freq) (freq / (25 * 1000 * 1000))

ret = ufs_qcom_set_core_clk_ctrl(hba, to_cycles_per_1us(max_freq),
to_cycles_per_40us(max_freq));

This also gives me an impression that the caller could just pass the max_freq
and the ufs_qcom_set_core_clk_ctrl() function could internally calculate 1us and
40us cycles value.

- Mani

> > + break;
> > + case MHZ_300:
> > + err = ufs_qcom_set_core_clk_ctrl(hba, 300, 12);
> > + break;
> > + case MHZ_201_5:
> > + err = ufs_qcom_set_core_clk_ctrl(hba, 202, 8);
> > + break;
> > + case MHZ_150:
> > + err = ufs_qcom_set_core_clk_ctrl(hba, 150, 6);
> > + break;
> > + case MHZ_100:
> > + err = ufs_qcom_set_core_clk_ctrl(hba, 100, 4);
> > + break;
> > + default:
> > + dev_err(hba->dev, "unipro max_freq=%u entry missing\n", max_freq);
>
> "UNIPRO clk max frequency (%u) not supported!"
>
> > + err = -EINVAL;
>
> -ERANGE
>
> > + break;
> > + }
> > +
> > + return err;
> > +}
> > static int ufs_qcom_link_startup_notify(struct ufs_hba *hba,
> > enum ufs_notify_change_status status)
> > {
> > @@ -686,12 +725,15 @@ static int ufs_qcom_link_startup_notify(struct ufs_hba *hba,
> > return -EINVAL;
> > }
> >
> > - if (ufs_qcom_cap_qunipro(host))
> > - /*
> > - * set unipro core clock cycles to 150 & clear clock
> > - * divider
> > - */
> > - err = ufs_qcom_set_core_clk_ctrl(hba, 150, 6);
> > + if (ufs_qcom_cap_qunipro(host)) {
> > + err = ufs_qcom_cfg_core_clk_ctrl(hba);
> > + if (err) {
> > + dev_err(hba->dev,
> > + "%s cfg core clk ctrl failed\n",
>
> "Failed to configure UNIPRO core clk"
>
> > + __func__);
> > + return err;
> > + }
> > + }
> >
> > /*
> > * Some UFS devices (and may be host) have issues if LCC is
> > @@ -1369,8 +1411,7 @@ static int ufs_qcom_clk_scale_up_post_change(struct ufs_hba *hba)
> > if (!ufs_qcom_cap_qunipro(host))
> > return 0;
> >
> > - /* set unipro core clock cycles to 150 and clear clock divider */
> > - return ufs_qcom_set_core_clk_ctrl(hba, 150, 6);
> > + return ufs_qcom_cfg_core_clk_ctrl(hba);
> > }
> >
> > static int ufs_qcom_clk_scale_down_pre_change(struct ufs_hba *hba)
> > @@ -1401,12 +1442,39 @@ static int ufs_qcom_clk_scale_down_pre_change(struct ufs_hba *hba)
> > static int ufs_qcom_clk_scale_down_post_change(struct ufs_hba *hba)
> > {
> > struct ufs_qcom_host *host = ufshcd_get_variant(hba);
> > + struct list_head *head = &hba->clk_list_head;
> > + struct ufs_clk_info *clki;
> > + u32 curr_freq = 0;
> > + int err;
> >
> > if (!ufs_qcom_cap_qunipro(host))
> > return 0;
> >
> > - /* set unipro core clock cycles to 75 and clear clock divider */
> > - return ufs_qcom_set_core_clk_ctrl(hba, 75, 3);
> > +
> > + list_for_each_entry(clki, head, list) {
> > + if (!IS_ERR_OR_NULL(clki->clk) &&
> > + !strcmp(clki->name, "core_clk_unipro")) {
> > + curr_freq = clk_get_rate(clki->clk);
> > + break;
> > + }
> > + }
> > + switch (curr_freq) {
> > + case MHZ_37_5:
> > + err = ufs_qcom_set_core_clk_ctrl(hba, 38, 2);
> > + break;
> > + case MHZ_75:
> > + err = ufs_qcom_set_core_clk_ctrl(hba, 75, 3);
> > + break;
> > + case MHZ_100:
> > + err = ufs_qcom_set_core_clk_ctrl(hba, 100, 4);
> > + break;
> > + default:
> > + err = -EINVAL;
> > + dev_err(hba->dev, "unipro curr_freq=%u entry missing\n", curr_freq);
> > + break;
> > + }
> > +
> > + return err;
>
> Why can't you use the existing ufs_qcom_cfg_core_clk_ctrl() function?
>
> - Mani
>
> > }
> >
> > static int ufs_qcom_clk_scale_notify(struct ufs_hba *hba,
> > diff --git a/drivers/ufs/host/ufs-qcom.h b/drivers/ufs/host/ufs-qcom.h
> > index 325f08aca260..56550fd36c4e 100644
> > --- a/drivers/ufs/host/ufs-qcom.h
> > +++ b/drivers/ufs/host/ufs-qcom.h
> > @@ -79,6 +79,15 @@ enum {
> > UFS_MEM_CQIS_VS = 0x8,
> > };
> >
> > +/* QCOM UFS host controller core clk frequencies */
> > +#define MHZ_37_5 37500000
> > +#define MHZ_50 50000000
> > +#define MHZ_75 75000000
> > +#define MHZ_100 100000000
> > +#define MHZ_150 150000000
> > +#define MHZ_300 300000000
> > +#define MHZ_201_5 201500000
> > +#define MHZ_403 403000000
> > #define UFS_CNTLR_2_x_x_VEN_REGS_OFFSET(x) (0x000 + x)
> > #define UFS_CNTLR_3_x_x_VEN_REGS_OFFSET(x) (0x400 + x)
> >
> > --
> > 2.17.1
> >
>
> --
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