From: Tony Lindgren <tony@atomide.com> To: Tero Kristo <t-kristo@ti.com> Cc: linux-omap@vger.kernel.org, linux-clk@vger.kernel.org, mturquette@baylibre.com, sboyd@codeaurora.org, linux-arm-kernel@lists.infradead.org Subject: Re: [RFC 6/9] clk: ti: add support for omap4 module clocks Date: Fri, 18 Dec 2015 07:36:06 -0800 [thread overview] Message-ID: <20151218153606.GJ23396@atomide.com> (raw) In-Reply-To: <1450447141-29936-7-git-send-email-t-kristo@ti.com> * Tero Kristo <t-kristo@ti.com> [151218 05:57]: > Previously, hwmod core has been used for controlling the hwmod level > clocks. This has certain drawbacks, like being unable to share the > clocks for multiple users, missing usecounting and generally being > totally incompatible with common clock framework. > > Add support for new clock type under the TI clock driver, which will > be used to convert all the existing hwmod clocks to. This helps to > get rid of the clock related hwmod data from kernel and instead > parsing this from DT. Good to see this happening, few comments on what I've noticed so far that should be considered. We should be able to do a generic "ti,mux-div-gate" clock and use it for the clkctrl too I think. See the suggested binding elsewhere in this thread. That would also work for the clkout register at least. Maybe the "ti,mux-div-gate" clock needs a separate clkctrl type compatible to know it needs to sleep to wait for the status bit. Also, we already know these clkctrl register do have multiple clocks, like the GPIO debounce and dividers for debugss clock. And we want to get rid of the overlapping reg entries. > +static int _omap4_hwmod_clk_enable(struct clk_hw *hw) > +{ > + struct clk_hw_omap *clk = to_clk_hw_omap(hw); > + u32 val; > + int timeout = 0; > + int ret; > + > + if (!clk->enable_bit) > + return 0; > + > + if (clk->clkdm) { > + ret = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk); > + if (ret) { > + WARN(1, > + "%s: could not enable %s's clockdomain %s: %d\n", > + __func__, clk_hw_get_name(hw), > + clk->clkdm_name, ret); > + return ret; > + } > + } > + > + val = ti_clk_ll_ops->clk_readl(clk->enable_reg); > + > + val &= ~OMAP4_MODULEMODE_MASK; > + val |= clk->enable_bit; > + > + ti_clk_ll_ops->clk_writel(val, clk->enable_reg); > + > + /* Wait until module is enabled */ > + while (!_omap4_is_ready(val)) { > + udelay(1); > + timeout++; > + if (timeout > OMAP4_MAX_MODULE_READY_TIME) { > + pr_err("%s: failed to enable\n", clk_hw_get_name(hw)); > + return -EBUSY; > + } > + val = ti_clk_ll_ops->clk_readl(clk->enable_reg); > + } > + > + return 0; > +} Clocks that need to wait to lock need to be set up with clk_prepare instead of clk_enable as pointed out by TGLX recently. Also see the "[PATCH] clk: ti: Fix FAPLL udelay in clk_enable with clk_prepare". Not sure what all needs to be fixed in the hwmod code for that to happen and PM to work, but that probably needs to be done first. Regards, Tony
WARNING: multiple messages have this Message-ID (diff)
From: tony@atomide.com (Tony Lindgren) To: linux-arm-kernel@lists.infradead.org Subject: [RFC 6/9] clk: ti: add support for omap4 module clocks Date: Fri, 18 Dec 2015 07:36:06 -0800 [thread overview] Message-ID: <20151218153606.GJ23396@atomide.com> (raw) In-Reply-To: <1450447141-29936-7-git-send-email-t-kristo@ti.com> * Tero Kristo <t-kristo@ti.com> [151218 05:57]: > Previously, hwmod core has been used for controlling the hwmod level > clocks. This has certain drawbacks, like being unable to share the > clocks for multiple users, missing usecounting and generally being > totally incompatible with common clock framework. > > Add support for new clock type under the TI clock driver, which will > be used to convert all the existing hwmod clocks to. This helps to > get rid of the clock related hwmod data from kernel and instead > parsing this from DT. Good to see this happening, few comments on what I've noticed so far that should be considered. We should be able to do a generic "ti,mux-div-gate" clock and use it for the clkctrl too I think. See the suggested binding elsewhere in this thread. That would also work for the clkout register at least. Maybe the "ti,mux-div-gate" clock needs a separate clkctrl type compatible to know it needs to sleep to wait for the status bit. Also, we already know these clkctrl register do have multiple clocks, like the GPIO debounce and dividers for debugss clock. And we want to get rid of the overlapping reg entries. > +static int _omap4_hwmod_clk_enable(struct clk_hw *hw) > +{ > + struct clk_hw_omap *clk = to_clk_hw_omap(hw); > + u32 val; > + int timeout = 0; > + int ret; > + > + if (!clk->enable_bit) > + return 0; > + > + if (clk->clkdm) { > + ret = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk); > + if (ret) { > + WARN(1, > + "%s: could not enable %s's clockdomain %s: %d\n", > + __func__, clk_hw_get_name(hw), > + clk->clkdm_name, ret); > + return ret; > + } > + } > + > + val = ti_clk_ll_ops->clk_readl(clk->enable_reg); > + > + val &= ~OMAP4_MODULEMODE_MASK; > + val |= clk->enable_bit; > + > + ti_clk_ll_ops->clk_writel(val, clk->enable_reg); > + > + /* Wait until module is enabled */ > + while (!_omap4_is_ready(val)) { > + udelay(1); > + timeout++; > + if (timeout > OMAP4_MAX_MODULE_READY_TIME) { > + pr_err("%s: failed to enable\n", clk_hw_get_name(hw)); > + return -EBUSY; > + } > + val = ti_clk_ll_ops->clk_readl(clk->enable_reg); > + } > + > + return 0; > +} Clocks that need to wait to lock need to be set up with clk_prepare instead of clk_enable as pointed out by TGLX recently. Also see the "[PATCH] clk: ti: Fix FAPLL udelay in clk_enable with clk_prepare". Not sure what all needs to be fixed in the hwmod code for that to happen and PM to work, but that probably needs to be done first. Regards, Tony
next prev parent reply other threads:[~2015-12-18 15:36 UTC|newest] Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-12-18 13:58 [RFC 0/9] ARM: OMAP4: hwmod clkctrl conversion to DT + clock driver Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 13:58 ` [RFC 1/9] ARM: OMAP2+: omap_device: create clock alias purely from DT data Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 15:16 ` Tony Lindgren 2015-12-18 15:16 ` Tony Lindgren 2015-12-18 13:58 ` [RFC 2/9] ARM: OMAP2+: hwmod: initialize main clocks directly from DT Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 13:58 ` [RFC 3/9] clk: ti: remove un-used definitions from public clk_hw_omap struct Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 13:58 ` [RFC 4/9] clk: ti: mux: export mux clock APIs locally Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 13:58 ` [RFC 5/9] dt-bindings: clk: ti: Document module clock type Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 13:58 ` [RFC 6/9] clk: ti: add support for omap4 module clocks Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 15:36 ` Tony Lindgren [this message] 2015-12-18 15:36 ` Tony Lindgren 2016-01-01 5:48 ` Michael Turquette 2016-01-01 5:48 ` Michael Turquette 2016-01-01 5:48 ` Michael Turquette 2016-01-04 7:36 ` Tero Kristo 2016-01-04 7:36 ` Tero Kristo 2016-01-04 7:36 ` Tero Kristo 2016-01-04 10:21 ` Geert Uytterhoeven 2016-01-04 10:21 ` Geert Uytterhoeven 2016-01-04 10:21 ` Geert Uytterhoeven 2016-01-04 13:27 ` Tero Kristo 2016-01-04 13:27 ` Tero Kristo 2016-01-04 14:42 ` Russell King - ARM Linux 2016-01-04 14:42 ` Russell King - ARM Linux 2016-01-04 16:37 ` Tony Lindgren 2016-01-04 16:37 ` Tony Lindgren 2016-01-04 19:15 ` Tero Kristo 2016-01-04 19:15 ` Tero Kristo 2016-01-05 1:23 ` Michael Turquette 2016-01-05 1:23 ` Michael Turquette 2016-01-05 1:23 ` Michael Turquette 2016-01-05 1:29 ` Michael Turquette 2016-01-05 1:29 ` Michael Turquette 2016-01-05 1:29 ` Michael Turquette 2015-12-18 13:58 ` [RFC 7/9] ARM: dts: omap4: add hwmod " Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 13:58 ` Tero Kristo 2015-12-18 15:06 ` Tony Lindgren 2015-12-18 15:06 ` Tony Lindgren 2015-12-18 13:59 ` [RFC 8/9] ARM: OMAP4: hwmod_data: use module clocks from DT Tero Kristo 2015-12-18 13:59 ` Tero Kristo 2015-12-18 13:59 ` Tero Kristo 2015-12-18 15:11 ` Tony Lindgren 2015-12-18 15:11 ` Tony Lindgren 2015-12-18 13:59 ` [RFC 9/9] clk: ti: omap4: update clock aliases to reflect new module clocks Tero Kristo 2015-12-18 13:59 ` Tero Kristo 2015-12-18 13:59 ` Tero Kristo
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