Messages in this thread |  | | Subject | Re: [PATCH V8 1/2] scsi: ufs: set the device reference clock setting | From | Sayali Lokhande <> | Date | Tue, 21 Aug 2018 15:08:54 +0530 |
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Hi Evan,
On 8/17/2018 10:57 PM, Evan Green wrote: > On Thu, Aug 9, 2018 at 2:10 AM Sayali Lokhande <sayalil@codeaurora.org> wrote: >> From: Subhash Jadavani <subhashj@codeaurora.org> >> >> 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@codeaurora.org> >> Signed-off-by: Can Guo <cang@codeaurora.org> >> Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org> >> --- >> drivers/scsi/ufs/ufs.h | 21 ++++++++++ >> drivers/scsi/ufs/ufshcd-pltfrm.c | 2 + >> drivers/scsi/ufs/ufshcd.c | 89 ++++++++++++++++++++++++++++++++++++++++ >> drivers/scsi/ufs/ufshcd.h | 2 + >> 4 files changed, 114 insertions(+) >> >> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h >> index 14e5bf7..c555ac0 100644 >> --- a/drivers/scsi/ufs/ufs.h >> +++ b/drivers/scsi/ufs/ufs.h >> @@ -378,6 +378,27 @@ enum query_opcode { >> UPIU_QUERY_OPCODE_TOGGLE_FLAG = 0x8, >> }; >> >> +/* bRefClkFreq attribute values */ >> +enum ref_clk_freq_hz { >> + REF_CLK_FREQ_19_2_MHZ = 19200000, >> + REF_CLK_FREQ_26_MHZ = 26000000, >> + REF_CLK_FREQ_38_4_MHZ = 38400000, >> + REF_CLK_FREQ_52_MHZ = 52000000, >> +}; >> + >> +enum bref_clk_freq { >> + bREF_CLK_FREQ_0, /* 19.2 MHz */ >> + bREF_CLK_FREQ_1, /* 26 MHz */ >> + bREF_CLK_FREQ_2, /* 38.4 MHz */ >> + bREF_CLK_FREQ_3, /* 52 MHz */ >> + bREF_CLK_FREQ_INVAL, >> +}; > These enums are not helpful, roughly the equivalent of VALUE_1000 = > 1000. Replace both with a single one, something like: > > enum ufs_ref_clk_freq { > UFS_REF_CLK_19P2MHZ = 0, > UFS_REF_CLK_26MHZ = 1, > UFS_REF_CLK_38P4MHZ = 2, > UFS_REF_CLK_52MHZ = 3, > UFS_REF_CLK_INVAL = -1 > }; Agreed. Will update. >> + >> +struct ufs_ref_clk { >> + enum ref_clk_freq_hz freq_hz; > Just make this an unsigned, no need for an enum of identity values. Done. >> + enum bref_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..0cbdde7 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[] = { >> + {REF_CLK_FREQ_19_2_MHZ, bREF_CLK_FREQ_0}, > Then these should just be something like: > {19200000, UFS_REF_CLK_19P2MHZ}, > ... > {0, UFS_REF_CLK_INVAL}, Done. >> + {REF_CLK_FREQ_26_MHZ, bREF_CLK_FREQ_1}, >> + {REF_CLK_FREQ_38_4_MHZ, bREF_CLK_FREQ_2}, >> + {REF_CLK_FREQ_52_MHZ, bREF_CLK_FREQ_3}, >> +}; >> + >> +static inline enum bref_clk_freq >> +ufs_get_bref_clk_for_ref_clk_freq_hz(u32 freq) >> +{ >> + enum bref_clk_freq val; >> + >> + for (val = bREF_CLK_FREQ_0; val <= bREF_CLK_FREQ_3; val++) > In my suggestion above, I terminated the table with {0, > UFS_REF_CLK_INVAL}. Then you could change this to a while loop that > stops when you see that sentinel node. I don't like the way it is now > because 1) You're making assumptions about the enum values being equal > to array indices, which may not line up if the next UFS spec adds > values that aren't contiguous (and defeats the whole point of the > table), and 2) Using <= LAST_VALID_VALUE makes this susceptible to > bugs when more valid values are added but someone forgets to go find > this loop and update it. Agreed. Will update. >> + if (ufs_ref_clk_freqs[val].freq_hz == freq) >> + return val; >> + >> + /* if no match found, return invalid*/ >> + return bREF_CLK_FREQ_INVAL; >> +} >> + >> +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; >> + >> + hba->dev_ref_clk_freq = bREF_CLK_FREQ_INVAL; >> + >> + refclk = of_clk_get_by_name(np, "ref_clk"); >> + if (!refclk) >> + return; >> + >> + freq = clk_get_rate(refclk); >> + if (freq > REF_CLK_FREQ_52_MHZ) { >> + dev_err(hba->dev, >> + "%s: invalid ref_clk setting = %d\n", >> + __func__, freq); >> + return; >> + } >> + >> + hba->dev_ref_clk_freq = >> + ufs_get_bref_clk_for_ref_clk_freq_hz(freq); >> +} >> + >> +static int ufshcd_set_dev_ref_clk(struct ufs_hba *hba) >> +{ >> + int err = 0; >> + int ref_clk = -1; >> + >> + 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, >> + &hba->dev_ref_clk_freq); > This is probably a nit, but I think the compiler is allowed to choose > any type for your enum that fits all of its values. This may not be a > u32, so you should probably create a u32 local, and assign into it > before passing a pointer into this function. > > Ah wait, I see that you made the member a u32. It might be nicer to > type the member as the enum, and then do this local conversion as I've > mentioned. That will allow the compiler to help check more. Agree. Will update. >> + >> + if (err) >> + dev_err(hba->dev, "%s: bRefClkFreq setting to %d Hz failed\n", >> + __func__, ufs_ref_clk_freqs[hba->dev_ref_clk_freq].freq_hz); >> + /* >> + * 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 %d Hz succeeded\n", >> + __func__, ufs_ref_clk_freqs[hba->dev_ref_clk_freq].freq_hz); >> + >> +out: >> + return err; >> +} >> + >> /** >> * ufshcd_probe_hba - probe hba to detect device and initialize >> * @hba: per-adapter instance >> @@ -6361,6 +6444,12 @@ static int ufshcd_probe_hba(struct ufs_hba *hba) >> "%s: Failed getting max supported power mode\n", >> __func__); >> } else { >> + /* >> + * Set the right value to bRefClkFreq before attempting to >> + * switch to HS gears. >> + */ >> + if (hba->dev_ref_clk_freq < bREF_CLK_FREQ_INVAL) >> + ufshcd_set_dev_ref_clk(hba); > As mentioned by other reviewers, you're calling this function, but you > haven't called ufshcd_parse_dev_ref_clk_freq in all cases that lead to > this. So this function is now setting 19.2MHz into a whole set of > devices who haven't specified it. Perhaps the initialization of the > member needs to go in ufshcd_alloc_host. (Look for callers of that to > find other paths that circumvent your parse function). I'm not sure > how to advise on enabling this functionality for non-DT machines. Agreed. Will add the parse function in ufshcd_alloc_host() itself (so that it can be called/initialised always). For non-DT users, even I am unsure. In current implementation, this will just set ref_clk as invalid and bail out(no update) for non-DT users. >> ret = ufshcd_config_pwr_mode(hba, &hba->max_pwr_info.info); >> if (ret) { >> dev_err(hba->dev, "%s: Failed setting power mode, err = %d\n", >> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h >> index 8110dcd..101a75c 100644 >> --- a/drivers/scsi/ufs/ufshcd.h >> +++ b/drivers/scsi/ufs/ufshcd.h >> @@ -548,6 +548,7 @@ struct ufs_hba { >> void *priv; >> unsigned int irq; >> bool is_irq_enabled; >> + u32 dev_ref_clk_freq; > As I mentioned above, this might be better as the enum type. Done. >> /* Interrupt aggregation support is broken */ >> #define UFSHCD_QUIRK_BROKEN_INTR_AGGR 0x1 >> @@ -746,6 +747,7 @@ static inline void ufshcd_rmwl(struct ufs_hba *hba, u32 mask, u32 val, u32 reg) >> int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask, >> u32 val, unsigned long interval_us, >> unsigned long timeout_ms, bool can_sleep); >> +void ufshcd_parse_dev_ref_clk_freq(struct ufs_hba *hba); > I wonder if this should fail if you end up finding a DT property, but > it's a crazy invalid value. What do you think? For any weird/invalid value ia parsed (from DT), we wont actually update the ref_clk in device and just bail out based on REF_CLK_INVAL check. >> static inline void check_upiu_size(void) >> { >> -- >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, >> a Linux Foundation Collaborative Project >>
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