From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tero Kristo Subject: Re: [PATCHv2 05/11] soc: ti: omap-prm: sync func clock status with resets Date: Fri, 30 Aug 2019 10:03:38 +0300 Message-ID: <7725d643-42ac-c3c1-9b07-ce2631fdb3c4@ti.com> References: <20190828071941.32378-1-t-kristo@ti.com> <20190828071941.32378-6-t-kristo@ti.com> <1567085114.5345.12.camel@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1567085114.5345.12.camel@pengutronix.de> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Philipp Zabel , ssantosh@kernel.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, robh+dt@kernel.org Cc: tony@atomide.com, devicetree@vger.kernel.org List-Id: linux-omap@vger.kernel.org On 29/08/2019 16:25, Philipp Zabel wrote: > On Wed, 2019-08-28 at 10:19 +0300, Tero Kristo wrote: >> Hardware reset signals are tightly coupled with associated clocks, and >> basically de-asserting a reset won't succeed properly if the clock is >> not enabled, and vice-versa. Also, disabling a clock won't fully succeed >> if the associated hardware resets are not asserted. Add status sync >> functionality between these two for TI drivers so that the situations >> can be handled properly without generating any timeouts. >> >> Signed-off-by: Tero Kristo >> --- >> drivers/soc/ti/omap_prm.c | 36 ++++++++++++++++++++++++++++++++++++ >> 1 file changed, 36 insertions(+) >> >> diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c >> index 38998ce19c71..e876bad8f8d5 100644 >> --- a/drivers/soc/ti/omap_prm.c >> +++ b/drivers/soc/ti/omap_prm.c >> @@ -15,6 +15,8 @@ >> #include >> #include >> #include >> +#include >> +#include >> >> #include >> >> @@ -42,7 +44,9 @@ struct omap_reset_data { >> struct reset_controller_dev rcdev; >> struct omap_prm *prm; >> struct clockdomain *clkdm; >> + struct clk *clk; >> struct device *dev; >> + u32 mask; >> }; >> >> #define to_omap_reset_data(p) container_of((p), struct omap_reset_data, rcdev) >> @@ -102,6 +106,8 @@ static int omap_reset_assert(struct reset_controller_dev *rcdev, >> v |= 1 << id; >> writel_relaxed(v, reset->prm->base + reset->prm->data->rstctrl); >> >> + ti_clk_notify_resets(reset->clk, v == reset->mask); >> + >> return 0; >> } >> >> @@ -163,9 +169,19 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, >> v &= ~(1 << id); >> writel_relaxed(v, reset->prm->base + reset->prm->data->rstctrl); >> >> + ti_clk_notify_resets(reset->clk, v == reset->mask); >> + >> if (!has_rstst) >> goto exit; >> >> + /* If associated clock is disabled, we can't poll completion status */ >> + if (reset->clk) { >> + struct clk_hw *hw = __clk_get_hw(reset->clk); >> + >> + if (!clk_hw_is_enabled(hw)) >> + return ret; >> + } >> + >> /* wait for the status to be set */ >> while (1) { >> v = readl_relaxed(reset->prm->base + reset->prm->data->rstst); >> @@ -199,8 +215,10 @@ static int omap_prm_reset_init(struct platform_device *pdev, >> struct omap_prm *prm) >> { >> struct omap_reset_data *reset; >> + const struct omap_rst_map *map; >> struct ti_prm_platform_data *pdata = dev_get_platdata(&pdev->dev); >> char buf[32]; >> + u32 v; >> >> /* >> * Check if we have controllable resets. If either rstctrl is non-zero >> @@ -215,6 +233,10 @@ static int omap_prm_reset_init(struct platform_device *pdev, >> !pdata->clkdm_allow_idle) >> return -EINVAL; >> >> + map = prm->data->rstmap; >> + if (!map) >> + return -EINVAL; > > Can this actually happen? It can, if user writes bad data to the omap_prm_data structs. Without this check it would make the probe crash which is bad. > >> + >> reset = devm_kzalloc(&pdev->dev, sizeof(*reset), GFP_KERNEL); >> if (!reset) >> return -ENOMEM; >> @@ -224,6 +246,10 @@ static int omap_prm_reset_init(struct platform_device *pdev, >> reset->rcdev.of_node = pdev->dev.of_node; >> reset->rcdev.nr_resets = OMAP_MAX_RESETS; >> reset->dev = &pdev->dev; >> + reset->clk = of_clk_get(pdev->dev.of_node, 0); >> + >> + if (IS_ERR(reset->clk)) >> + reset->clk = NULL; > > Maybe only ignore -ENOENT? Yeah, I can modify this. > >> reset->prm = prm; >> >> @@ -234,6 +260,16 @@ static int omap_prm_reset_init(struct platform_device *pdev, >> if (!reset->clkdm) >> return -EINVAL; >> >> + while (map->rst >= 0) { >> + reset->mask |= BIT(map->rst); >> + map++; >> + } > > With this, you could use reset->mask to simplify _is_valid_reset. True, let me re-write it. -Tero -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki