* Re: [PATCH v2] scsi: ufs: add clock-scalable property for clk scaling
2022-05-07 4:57 ` [PATCH v2] scsi: ufs: add clock-scalable property for clk scaling Po-Wen Kao
@ 2022-05-09 2:57 ` Po-Wen Kao
0 siblings, 0 replies; 2+ messages in thread
From: Po-Wen Kao @ 2022-05-09 2:57 UTC (permalink / raw)
To: j-young.choi, Alim Akhtar, Avri Altman, James E.J. Bottomley,
Martin K. Petersen, Steven Rostedt, Ingo Molnar,
Matthias Brugger
Cc: wsd_upstream, peter.wang, stanley.chu, alice.chao, chun-hung.wu,
cc.chou, chaotian.jing, jiajie.hao, linux-scsi, linux-kernel,
linux-arm-kernel, linux-mediatek
Update missing cover letter
V2 changes
- Cleaner code path as suggested. e.g. return directly
- Wrap clk_set_rate() with ufshcd_clk_set_rate() to check on "scalable".
On 5/7/22 12:57 PM, Po-Wen Kao wrote:
> In clk scaling, clk_set_rate is invoked to set dedicated PLL clk rate
> on scale up and down. On some MTK platform, scaling is only possible
> by switching parent of a mux, therefore we introduce a new
> "clock-scalable" property to gain fine control over which clock rate can
> be scaled by calling clk_set_rate. If a clock is defined as non-scalable,
> clk_set_rate won't be invoked while clki->current_rate is still updated
> if min/max freq is defined. Customized clk operation may be embedded in
> pre/post change of hba->vops->clk_scale_notify.
>
> All clocks in dts without "clock-scalable" property defined are assumed
> scalable and works as usual. There is no neeed to make change on existing
> dts.
>
> To specify scalable property, one may define dts as follow
>
> &ufshci {
> clocks =
> <clk1>,
> <clk2>,
> ...
> <clkn>;
>
> clock-names =
> "clk1",
> "clk2",
> ...
> "clkn";
>
> freq-table-hz =
> <1000 2000>,
> <0 0>,
> ...
> <0 0>;
>
> clock-scalable =
> <0
> 0
> ...
> 0
> >;
> };
>
> Signed-off-by: Po-Wen Kao <powen.kao@mediatek.com>
> ---
> drivers/scsi/ufs/ufshcd-pltfrm.c | 96 +++++++++++++++++++++++---------
> drivers/scsi/ufs/ufshcd.c | 54 +++++++-----------
> drivers/scsi/ufs/ufshcd.h | 2 +
> include/trace/events/ufs.h | 16 +++---
> 4 files changed, 102 insertions(+), 66 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
> index 87975d1a21c8..5f95bb519485 100644
> --- a/drivers/scsi/ufs/ufshcd-pltfrm.c
> +++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
> @@ -18,6 +18,56 @@
>
> #define UFSHCD_DEFAULT_LANES_PER_DIRECTION 2
>
> +/**
> + * ufshcd_get_clk_u32_array - Resolve property in dts to u32 array with
> + * shape check.
> + * @hba: per-adapter instance
> + * @propname: name of property
> + * @cols: column count
> + * @rows: calculated row count with given cols
> + * @array: u32 array pointer of property data with propname
> + */
> +static int ufshcd_get_clk_u32_array(struct ufs_hba *hba, const char *propname,
> + size_t cols, size_t *rows, u32 **array)
> +{
> + struct device *dev = hba->dev;
> + struct device_node *np = dev->of_node;
> + int len = 0, ret = 0;
> + int _rows = 0;
> +
> + if (!of_get_property(np, propname, &len)) {
> + dev_warn(dev, "%s property not specified.\n", propname);
> + return -EINVAL;
> + }
> +
> + len = len / sizeof(**array);
> + if (!cols || !len || len % cols != 0) {
> + dev_warn(dev, "%s property define error.\n", propname);
> + return -EINVAL;
> + }
> + _rows = len / cols;
> +
> + *array = devm_kcalloc(dev, len, sizeof(**array), GFP_KERNEL);
> + if (!*array) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + ret = of_property_read_u32_array(np, propname, *array, len);
> + if (ret) {
> + dev_err(dev, "%s: error reading array %d\n",
> + propname, ret);
> + goto out;
> + }
> +
> + *rows = _rows;
> +
> + return 0;
> +out:
> + devm_kfree(dev, *array);
> + return ret;
> +}
> +
> static int ufshcd_parse_clock_info(struct ufs_hba *hba)
> {
> int ret = 0;
> @@ -27,13 +77,14 @@ static int ufshcd_parse_clock_info(struct ufs_hba *hba)
> struct device_node *np = dev->of_node;
> char *name;
> u32 *clkfreq = NULL;
> + u32 *scalable = NULL;
> struct ufs_clk_info *clki;
> - int len = 0;
> size_t sz = 0;
>
> if (!np)
> goto out;
>
> + /* clock-names */
> cnt = of_property_count_strings(np, "clock-names");
> if (!cnt || (cnt == -EINVAL)) {
> dev_info(dev, "%s: Unable to find clocks, assuming enabled\n",
> @@ -47,37 +98,29 @@ static int ufshcd_parse_clock_info(struct ufs_hba *hba)
> if (cnt <= 0)
> goto out;
>
> - if (!of_get_property(np, "freq-table-hz", &len)) {
> - dev_info(dev, "freq-table-hz property not specified\n");
> + /* clock-scalable (optional) */
> + ret = ufshcd_get_clk_u32_array(hba, "clock-scalable", 1, &sz, &scalable);
> + if (ret) {
> + dev_warn(dev, "Optional property %s load failed. Assume all clocks scalable.\n",
> + "clock-scalable");
> + } else if (sz != cnt) {
> + dev_err(dev, "%s len mismatch\n", "clock-scalable");
> + ret = -EINVAL;
> goto out;
> }
>
> - if (len <= 0)
> + /* freq-table-hz */
> + ret = ufshcd_get_clk_u32_array(hba, "freq-table-hz", 2, &sz, &clkfreq);
> + if (ret) {
> + dev_err(dev, "Property %s load failed.", "freq-table-hz");
> goto out;
> -
> - sz = len / sizeof(*clkfreq);
> - if (sz != 2 * cnt) {
> + } else if (sz != cnt) {
> dev_err(dev, "%s len mismatch\n", "freq-table-hz");
> ret = -EINVAL;
> goto out;
> }
>
> - clkfreq = devm_kcalloc(dev, sz, sizeof(*clkfreq),
> - GFP_KERNEL);
> - if (!clkfreq) {
> - ret = -ENOMEM;
> - goto out;
> - }
> -
> - ret = of_property_read_u32_array(np, "freq-table-hz",
> - clkfreq, sz);
> - if (ret && (ret != -EINVAL)) {
> - dev_err(dev, "%s: error reading array %d\n",
> - "freq-table-hz", ret);
> - return ret;
> - }
> -
> - for (i = 0; i < sz; i += 2) {
> + for (i = 0; i < cnt * 2; i += 2) {
> ret = of_property_read_string_index(np,
> "clock-names", i/2, (const char **)&name);
> if (ret)
> @@ -92,6 +135,7 @@ static int ufshcd_parse_clock_info(struct ufs_hba *hba)
> clki->min_freq = clkfreq[i];
> clki->max_freq = clkfreq[i+1];
> clki->name = devm_kstrdup(dev, name, GFP_KERNEL);
> + clki->scalable = scalable ? !!scalable[i / 2] : true;
> if (!clki->name) {
> ret = -ENOMEM;
> goto out;
> @@ -99,11 +143,13 @@ static int ufshcd_parse_clock_info(struct ufs_hba *hba)
>
> if (!strcmp(name, "ref_clk"))
> clki->keep_link_active = true;
> - dev_dbg(dev, "%s: min %u max %u name %s\n", "freq-table-hz",
> - clki->min_freq, clki->max_freq, clki->name);
> + dev_dbg(dev, "clk %s: scalable(%u), min(%u), max(%u)\n",
> + clki->name, clki->scalable, clki->min_freq, clki->max_freq);
> list_add_tail(&clki->list, &hba->clk_list_head);
> }
> out:
> + devm_kfree(dev, scalable);
> + devm_kfree(dev, clkfreq);
> return ret;
> }
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index eea5af5fa166..8dbae2f73329 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -939,6 +939,11 @@ static bool ufshcd_is_unipro_pa_params_tuning_req(struct ufs_hba *hba)
> return false;
> }
>
> +static inline int ufshcd_clk_set_rate(struct ufs_clk_info *clki, unsigned long rate)
> +{
> + return clki->scalable ? clk_set_rate(clki->clk, rate) : 0;
> +}
> +
> /**
> * ufshcd_set_clk_freq - set UFS controller clock frequencies
> * @hba: per adapter instance
> @@ -950,6 +955,7 @@ static bool ufshcd_is_unipro_pa_params_tuning_req(struct ufs_hba *hba)
> static int ufshcd_set_clk_freq(struct ufs_hba *hba, bool scale_up)
> {
> int ret = 0;
> + u32 target_rate = 0;
> struct ufs_clk_info *clki;
> struct list_head *head = &hba->clk_list_head;
>
> @@ -958,41 +964,23 @@ static int ufshcd_set_clk_freq(struct ufs_hba *hba, bool scale_up)
>
> list_for_each_entry(clki, head, list) {
> if (!IS_ERR_OR_NULL(clki->clk)) {
> - if (scale_up && clki->max_freq) {
> - if (clki->curr_freq == clki->max_freq)
> - continue;
> -
> - ret = clk_set_rate(clki->clk, clki->max_freq);
> - if (ret) {
> - dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
> - __func__, clki->name,
> - clki->max_freq, ret);
> - break;
> - }
> - trace_ufshcd_clk_scaling(dev_name(hba->dev),
> - "scaled up", clki->name,
> - clki->curr_freq,
> - clki->max_freq);
> -
> - clki->curr_freq = clki->max_freq;
> + target_rate = scale_up ? clki->max_freq : clki->min_freq;
>
> - } else if (!scale_up && clki->min_freq) {
> - if (clki->curr_freq == clki->min_freq)
> - continue;
> + if (!target_rate || clki->curr_freq == target_rate)
> + continue;
>
> - ret = clk_set_rate(clki->clk, clki->min_freq);
> - if (ret) {
> - dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
> - __func__, clki->name,
> - clki->min_freq, ret);
> - break;
> - }
> - trace_ufshcd_clk_scaling(dev_name(hba->dev),
> - "scaled down", clki->name,
> - clki->curr_freq,
> - clki->min_freq);
> - clki->curr_freq = clki->min_freq;
> + ret = ufshcd_clk_set_rate(clki, target_rate);
> + if (ret) {
> + dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
> + __func__, clki->name,
> + target_rate, ret);
> + break;
> }
> + trace_ufshcd_clk_scaling(dev_name(hba->dev),
> + clki->name, scale_up,
> + clki->curr_freq,
> + target_rate);
> + clki->curr_freq = target_rate;
> }
> dev_dbg(hba->dev, "%s: clk: %s, rate: %lu\n", __func__,
> clki->name, clk_get_rate(clki->clk));
> @@ -8364,7 +8352,7 @@ static int ufshcd_init_clocks(struct ufs_hba *hba)
> ufshcd_parse_dev_ref_clk_freq(hba, clki->clk);
>
> if (clki->max_freq) {
> - ret = clk_set_rate(clki->clk, clki->max_freq);
> + ret = ufshcd_clk_set_rate(clki, clki->max_freq);
> if (ret) {
> dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
> __func__, clki->name,
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 1637f5cc1420..eaa3d6c5b9ab 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -260,6 +260,7 @@ struct ufs_dev_cmd {
> * @keep_link_active: indicates that the clk should not be disabled if
> link is active
> * @enabled: variable to check against multiple enable/disable
> + * @scalable: indicates if clk is scalable in clk scaling
> */
> struct ufs_clk_info {
> struct list_head list;
> @@ -270,6 +271,7 @@ struct ufs_clk_info {
> u32 curr_freq;
> bool keep_link_active;
> bool enabled;
> + bool scalable;
> };
>
> enum ufs_notify_change_status {
> diff --git a/include/trace/events/ufs.h b/include/trace/events/ufs.h
> index 599739ee7b20..780c964e52c2 100644
> --- a/include/trace/events/ufs.h
> +++ b/include/trace/events/ufs.h
> @@ -103,30 +103,30 @@ TRACE_EVENT(ufshcd_clk_gating,
>
> TRACE_EVENT(ufshcd_clk_scaling,
>
> - TP_PROTO(const char *dev_name, const char *state, const char *clk,
> - u32 prev_state, u32 curr_state),
> + TP_PROTO(const char *dev_name, const char *clk,
> + bool up, u32 prev_state, u32 curr_state),
>
> - TP_ARGS(dev_name, state, clk, prev_state, curr_state),
> + TP_ARGS(dev_name, clk, up, prev_state, curr_state),
>
> TP_STRUCT__entry(
> __string(dev_name, dev_name)
> - __string(state, state)
> __string(clk, clk)
> + __field(bool, up)
> __field(u32, prev_state)
> __field(u32, curr_state)
> ),
>
> TP_fast_assign(
> __assign_str(dev_name, dev_name);
> - __assign_str(state, state);
> __assign_str(clk, clk);
> + __entry->up = up;
> __entry->prev_state = prev_state;
> __entry->curr_state = curr_state;
> ),
>
> - TP_printk("%s: %s %s from %u to %u Hz",
> - __get_str(dev_name), __get_str(state), __get_str(clk),
> - __entry->prev_state, __entry->curr_state)
> + TP_printk("%s: scaled %s %s from %u to %u Hz",
> + __get_str(dev_name), __entry->up ? "up" : "down", __get_str(clk),
> + __entry->prev_state, __entry->curr_state)
> );
>
> TRACE_EVENT(ufshcd_auto_bkops_state,
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