On Fri, Sep 14, 2018 at 2:43 AM Sayali Lokhande <sayalil@xxxxxxxxxxxxxx> wrote:
>
> From: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
>
> UFS host supplies the reference clock to UFS device and UFS device
> specification allows host to provide one of the 4 frequencies (19.2 MHz,
> 26 MHz, 38.4 MHz, 52 MHz) for reference clock. Host should set the
> device reference clock frequency setting in the device based on what
> frequency it is supplying to UFS device.
>
> Signed-off-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
> Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
> Signed-off-by: Sayali Lokhande <sayalil@xxxxxxxxxxxxxx>
> ---
> drivers/scsi/ufs/ufs.h | 14 +++++++
> drivers/scsi/ufs/ufshcd-pltfrm.c | 2 +
> drivers/scsi/ufs/ufshcd.c | 90 ++++++++++++++++++++++++++++++++++++++++
> drivers/scsi/ufs/ufshcd.h | 2 +
> 4 files changed, 108 insertions(+)
>
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index 14e5bf7..a2e76b1 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -378,6 +378,20 @@ enum query_opcode {
> UPIU_QUERY_OPCODE_TOGGLE_FLAG = 0x8,
> };
>
> +/* bRefClkFreq attribute values */
> +enum ufs_ref_clk_freq {
> + REF_CLK_FREQ_19_2_MHZ = 0,
> + REF_CLK_FREQ_26_MHZ = 1,
> + REF_CLK_FREQ_38_4_MHZ = 2,
> + REF_CLK_FREQ_52_MHZ = 3,
> + REF_CLK_FREQ_INVAL = -1,
> +};
> +
> +struct ufs_ref_clk {
> + u32 freq_hz;
> + enum ufs_ref_clk_freq val;
> +};
> +
> /* Query response result code */
> enum {
> QUERY_RESULT_SUCCESS = 0x00,
> diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
> index e82bde0..0953563 100644
> --- a/drivers/scsi/ufs/ufshcd-pltfrm.c
> +++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
> @@ -343,6 +343,8 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
> pm_runtime_set_active(&pdev->dev);
> pm_runtime_enable(&pdev->dev);
>
> + ufshcd_parse_dev_ref_clk_freq(hba);
> +
> 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 c5b1bf1..e01cdc0 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -6296,6 +6296,89 @@ static void ufshcd_def_desc_sizes(struct ufs_hba *hba)
> hba->desc_size.hlth_desc = QUERY_DESC_HEALTH_DEF_SIZE;
> }
>
> +static struct ufs_ref_clk ufs_ref_clk_freqs[] = {
> + {19200000, REF_CLK_FREQ_19_2_MHZ},
> + {26000000, REF_CLK_FREQ_26_MHZ},
> + {38400000, REF_CLK_FREQ_38_4_MHZ},
> + {52000000, REF_CLK_FREQ_52_MHZ},
> + {0, REF_CLK_FREQ_INVAL},
> +};
> +
> +static inline enum ufs_ref_clk_freq
> +ufs_get_bref_clk_from_hz(u32 freq)
> +{
> + int i = 0;
> +
> + while (ufs_ref_clk_freqs[i].freq_hz != freq) {
> + if (!ufs_ref_clk_freqs[i].freq_hz)
> + return REF_CLK_FREQ_INVAL;
> + i++;
> + }
> +
> + return ufs_ref_clk_freqs[i].val;
> +}
> +
> +void ufshcd_parse_dev_ref_clk_freq(struct ufs_hba *hba)
> +{
> + struct device *dev = hba->dev;
> + struct device_node *np = dev->of_node;
> + struct clk *refclk = NULL;
> + u32 freq = 0;
> +
> + if (!np)
> + return;
> +
> + refclk = of_clk_get_by_name(np, "ref_clk");
> + if (!refclk)
> + return;
> +
> + freq = clk_get_rate(refclk);
> +
> + hba->dev_ref_clk_freq =
> + ufs_get_bref_clk_from_hz(freq);
> +
> + if (hba->dev_ref_clk_freq == REF_CLK_FREQ_INVAL)
> + dev_err(hba->dev,
> + "%s: invalid ref_clk setting = %d\n",
> + __func__, freq);
> +}
> +
> +static int ufshcd_set_dev_ref_clk(struct ufs_hba *hba)
> +{
> + int err, ref_clk = -1;
> + u32 freq = hba->dev_ref_clk_freq;
> +
> + err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_READ_ATTR,
> + QUERY_ATTR_IDN_REF_CLK_FREQ, 0, 0, &ref_clk);
> +
> + if (err) {
> + dev_err(hba->dev, "%s: failed reading bRefClkFreq. err = %d\n",
> + __func__, err);
> + goto out;
> + }
> +
> + if (ref_clk == hba->dev_ref_clk_freq)
> + goto out; /* nothing to update */
> +
> + err = ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
> + QUERY_ATTR_IDN_REF_CLK_FREQ, 0, 0, &freq);
> +
> + if (err) {
> + dev_err(hba->dev, "%s: bRefClkFreq setting to %u Hz failed\n",
> + __func__, ufs_ref_clk_freqs[freq].freq_hz);
> + goto out;
> + }
> + /*
> + * It is good to print this out here to debug any later failures
> + * related to gear switch.
> + */
> + dev_dbg(hba->dev, "%s: bRefClkFreq setting to %u Hz succeeded\n",
> + __func__, ufs_ref_clk_freqs[freq].freq_hz);
> +
The comment above doesn't add any value in my opinion. Other than that:
Reviewed-by: Evan Green <evgreen@xxxxxxxxxxxx>
