When adding perf support later the DFI must be enabled when either of devfreq-event or perf is active. Prepare for that by adding a usage counter for the DFI. Also move enabling and disabling of the clock away from the devfreq-event specific functions to which the perf specific part won't have access. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Reviewed-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230524083153.2046084-15-s.hauer@xxxxxxxxxxxxxx Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> --- drivers/devfreq/event/rockchip-dfi.c | 57 +++++++++++++++++++--------- 1 file changed, 40 insertions(+), 17 deletions(-) diff --git a/drivers/devfreq/event/rockchip-dfi.c b/drivers/devfreq/event/rockchip-dfi.c index d39db5de7f19c..8a7af7c32ae0d 100644 --- a/drivers/devfreq/event/rockchip-dfi.c +++ b/drivers/devfreq/event/rockchip-dfi.c @@ -68,13 +68,28 @@ struct rockchip_dfi { void __iomem *regs; struct regmap *regmap_pmu; struct clk *clk; + int usecount; + struct mutex mutex; u32 ddr_type; unsigned int channel_mask; }; -static void rockchip_dfi_start_hardware_counter(struct rockchip_dfi *dfi) +static int rockchip_dfi_enable(struct rockchip_dfi *dfi) { void __iomem *dfi_regs = dfi->regs; + int ret = 0; + + mutex_lock(&dfi->mutex); + + dfi->usecount++; + if (dfi->usecount > 1) + goto out; + + ret = clk_prepare_enable(dfi->clk); + if (ret) { + dev_err(&dfi->edev->dev, "failed to enable dfi clk: %d\n", ret); + goto out; + } /* clear DDRMON_CTRL setting */ writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_TIMER_CNT_EN | DDRMON_CTRL_SOFTWARE_EN | @@ -99,14 +114,30 @@ static void rockchip_dfi_start_hardware_counter(struct rockchip_dfi *dfi) /* enable count, use software mode */ writel_relaxed(HIWORD_UPDATE(DDRMON_CTRL_SOFTWARE_EN, DDRMON_CTRL_SOFTWARE_EN), dfi_regs + DDRMON_CTRL); +out: + mutex_unlock(&dfi->mutex); + + return ret; } -static void rockchip_dfi_stop_hardware_counter(struct rockchip_dfi *dfi) +static void rockchip_dfi_disable(struct rockchip_dfi *dfi) { void __iomem *dfi_regs = dfi->regs; + mutex_lock(&dfi->mutex); + + dfi->usecount--; + + WARN_ON_ONCE(dfi->usecount < 0); + + if (dfi->usecount > 0) + goto out; + writel_relaxed(HIWORD_UPDATE(0, DDRMON_CTRL_SOFTWARE_EN), dfi_regs + DDRMON_CTRL); + clk_disable_unprepare(dfi->clk); +out: + mutex_unlock(&dfi->mutex); } static void rockchip_dfi_read_counters(struct rockchip_dfi *dfi, struct dmc_count *count) @@ -124,29 +155,20 @@ static void rockchip_dfi_read_counters(struct rockchip_dfi *dfi, struct dmc_coun } } -static int rockchip_dfi_disable(struct devfreq_event_dev *edev) +static int rockchip_dfi_event_disable(struct devfreq_event_dev *edev) { struct rockchip_dfi *dfi = devfreq_event_get_drvdata(edev); - rockchip_dfi_stop_hardware_counter(dfi); - clk_disable_unprepare(dfi->clk); + rockchip_dfi_disable(dfi); return 0; } -static int rockchip_dfi_enable(struct devfreq_event_dev *edev) +static int rockchip_dfi_event_enable(struct devfreq_event_dev *edev) { struct rockchip_dfi *dfi = devfreq_event_get_drvdata(edev); - int ret; - - ret = clk_prepare_enable(dfi->clk); - if (ret) { - dev_err(&edev->dev, "failed to enable dfi clk: %d\n", ret); - return ret; - } - rockchip_dfi_start_hardware_counter(dfi); - return 0; + return rockchip_dfi_enable(dfi); } static int rockchip_dfi_set_event(struct devfreq_event_dev *edev) @@ -190,8 +212,8 @@ static int rockchip_dfi_get_event(struct devfreq_event_dev *edev, } static const struct devfreq_event_ops rockchip_dfi_ops = { - .disable = rockchip_dfi_disable, - .enable = rockchip_dfi_enable, + .disable = rockchip_dfi_event_disable, + .enable = rockchip_dfi_event_enable, .get_event = rockchip_dfi_get_event, .set_event = rockchip_dfi_set_event, }; @@ -272,6 +294,7 @@ static int rockchip_dfi_probe(struct platform_device *pdev) return PTR_ERR(dfi->regmap_pmu); dfi->dev = dev; + mutex_init(&dfi->mutex); desc = &dfi->desc; desc->ops = &rockchip_dfi_ops; -- 2.39.2
