From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Cercueil Subject: Re: [PATCH v13 05/13] clk: ingenic: Add driver for the TCU clocks Date: Wed, 26 Jun 2019 00:37:07 +0200 Message-ID: <1561502227.10069.1@crapouillou.net> References: <20190624225759.18299-1-paul@crapouillou.net> <20190624225759.18299-6-paul@crapouillou.net> <20190625220931.2F69B2086D@mail.kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20190625220931.2F69B2086D@mail.kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Stephen Boyd Cc: Daniel Lezcano , James Hogan , Jason Cooper , Jonathan Corbet , Lee Jones , Marc Zyngier , Michael Turquette , Paul Burton , Ralf Baechle , Thomas Gleixner , Mathieu Malaterre , od@zcrc.me, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-doc@vger.kernel.org, linux-clk@vger.kernel.org, Artur Rojek List-Id: devicetree@vger.kernel.org Le mer. 26 juin 2019 =E0 0:09, Stephen Boyd a =E9crit : > Quoting Paul Cercueil (2019-06-24 15:57:51) >> diff --git a/drivers/clk/ingenic/tcu.c b/drivers/clk/ingenic/tcu.c >> new file mode 100644 >> index 000000000000..6d667c4a2bd5 >> --- /dev/null >> +++ b/drivers/clk/ingenic/tcu.c >> @@ -0,0 +1,473 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * JZ47xx SoCs TCU clocks driver >> + * Copyright (C) 2019 Paul Cercueil >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +#include >> + > [...] >> + >> +static const struct ingenic_soc_info jz4740_soc_info =3D { >> + .num_channels =3D 8, >> + .has_ost =3D false, >> + .has_tcu_clk =3D true, >> +}; >> + >> +static const struct ingenic_soc_info jz4725b_soc_info =3D { >> + .num_channels =3D 6, >> + .has_ost =3D true, >> + .has_tcu_clk =3D true, >> +}; >> + >> +static const struct ingenic_soc_info jz4770_soc_info =3D { >> + .num_channels =3D 8, >> + .has_ost =3D true, >> + .has_tcu_clk =3D false, >> +}; >> + >> +static const struct of_device_id ingenic_tcu_of_match[]=20 >> __initconst =3D { >> + { .compatible =3D "ingenic,jz4740-tcu", .data =3D=20 >> &jz4740_soc_info, }, >> + { .compatible =3D "ingenic,jz4725b-tcu", .data =3D=20 >> &jz4725b_soc_info, }, >> + { .compatible =3D "ingenic,jz4770-tcu", .data =3D=20 >> &jz4770_soc_info, }, >> + { } >> +}; >> + >> +static int __init ingenic_tcu_probe(struct device_node *np) >> +{ >> + const struct of_device_id *id =3D=20 >> of_match_node(ingenic_tcu_of_match, np); >> + struct ingenic_tcu *tcu; >> + struct regmap *map; >> + unsigned int i; >> + int ret; >> + >> + map =3D ingenic_tcu_get_regmap(np); >> + if (IS_ERR(map)) >> + return PTR_ERR(map); >> + >> + tcu =3D kzalloc(sizeof(*tcu), GFP_KERNEL); >> + if (!tcu) >> + return -ENOMEM; >> + >> + tcu->map =3D map; >> + tcu->soc_info =3D id->data; >> + >> + if (tcu->soc_info->has_tcu_clk) { >> + tcu->clk =3D of_clk_get_by_name(np, "tcu"); >=20 > Do you need to get the clk by name? Or can that clk be "known" to the > TCU somehow so we can already have a direct clk pointer? This clock is provided by a separate driver, so I have to obtain the clock pointer from devicetree. >=20 >> + if (IS_ERR(tcu->clk)) { >> + ret =3D PTR_ERR(tcu->clk); >> + pr_crit("Cannot get TCU clock\n"); >> + goto err_free_tcu; >> + } >> + >> + ret =3D clk_prepare_enable(tcu->clk); >> + if (ret) { >> + pr_crit("Unable to enable TCU clock\n"); >> + goto err_put_clk; >> + } >> + } >> + >> + tcu->clocks =3D kzalloc(sizeof(*tcu->clocks) + >> + sizeof(*tcu->clocks->hws) *=20 >> TCU_CLK_COUNT, >> + GFP_KERNEL); >> + if (!tcu->clocks) { >> + ret =3D -ENOMEM; >> + goto err_clk_disable; >> + } >> + >> + tcu->clocks->num =3D TCU_CLK_COUNT; >> + >> + for (i =3D 0; i < tcu->soc_info->num_channels; i++) { >> + ret =3D ingenic_tcu_register_clock(tcu, i,=20 >> TCU_PARENT_EXT, >> + =20 >> &ingenic_tcu_clk_info[i], >> + tcu->clocks); >> + if (ret) { >> + pr_crit("cannot register clock %i\n", i); >> + goto err_unregister_timer_clocks; >> + } >> + } >> + >> + /* >> + * We set EXT as the default parent clock for all the TCU=20 >> clocks >> + * except for the watchdog one, where we set the RTC clock=20 >> as the >> + * parent. Since the EXT and PCLK are much faster than the=20 >> RTC clock, >> + * the watchdog would kick after a maximum time of 5s, and=20 >> we might >> + * want a slower kicking time. >> + */ >> + ret =3D ingenic_tcu_register_clock(tcu, TCU_CLK_WDT,=20 >> TCU_PARENT_RTC, >> + =20 >> &ingenic_tcu_watchdog_clk_info, >> + tcu->clocks); >> + if (ret) { >> + pr_crit("cannot register watchdog clock\n"); >> + goto err_unregister_timer_clocks; >> + } >> + >> + if (tcu->soc_info->has_ost) { >> + ret =3D ingenic_tcu_register_clock(tcu, TCU_CLK_OST, >> + TCU_PARENT_EXT, >> + =20 >> &ingenic_tcu_ost_clk_info, >> + tcu->clocks); >> + if (ret) { >> + pr_crit("cannot register ost clock\n"); >> + goto err_unregister_watchdog_clock; >> + } >> + } >> + >> + ret =3D of_clk_add_hw_provider(np, of_clk_hw_onecell_get,=20 >> tcu->clocks); >> + if (ret) { >> + pr_crit("cannot add OF clock provider\n"); >> + goto err_unregister_ost_clock; >> + } >> + >> + ingenic_tcu =3D tcu; >> + >> + return 0; >> + >> +err_unregister_ost_clock: >> + if (tcu->soc_info->has_ost) >> + clk_hw_unregister(tcu->clocks->hws[i + 1]); >> +err_unregister_watchdog_clock: >> + clk_hw_unregister(tcu->clocks->hws[i]); >> +err_unregister_timer_clocks: >> + for (i =3D 0; i < tcu->clocks->num; i++) >> + if (tcu->clocks->hws[i]) >> + clk_hw_unregister(tcu->clocks->hws[i]); >> + kfree(tcu->clocks); >> +err_clk_disable: >> + if (tcu->soc_info->has_tcu_clk) >> + clk_disable_unprepare(tcu->clk); >> +err_put_clk: >> + if (tcu->soc_info->has_tcu_clk) >> + clk_put(tcu->clk); >> +err_free_tcu: >> + kfree(tcu); >> + return ret; >=20 > Too bad this isn't a device with devm! >=20 >> +} >> + >> +static int __maybe_unused tcu_pm_suspend(void) >> +{ >> + struct ingenic_tcu *tcu =3D ingenic_tcu; >> + >> + if (tcu->clk) >> + clk_disable(tcu->clk); >=20 > Do you need to unprepare? Or it just isn't possible because this is > called from syscore and thus we can't sleep? I thought that clk_disable() was enough. We don't actually need to unprepare, do we? And yes, as you pointed out, this call cannot sleep. >> + >> + return 0; >> +} >> + >> +static void __maybe_unused tcu_pm_resume(void) >> +{ >> + struct ingenic_tcu *tcu =3D ingenic_tcu; >> + >> + if (tcu->clk) >> + clk_enable(tcu->clk); >> +} >> + >> +static struct syscore_ops __maybe_unused tcu_pm_ops =3D { >> + .suspend =3D tcu_pm_suspend, >> + .resume =3D tcu_pm_resume, >> +}; >> + >> +static void __init ingenic_tcu_init(struct device_node *np) >> +{ >> + int ret =3D ingenic_tcu_probe(np); >> + >> + if (ret) >> + pr_crit("Failed to initialize TCU clocks: %i\n",=20 >> ret); >=20 > Should be %d instead of %i? Applies to all this file. OK. Thanks, -Paul >> + >> + if (IS_ENABLED(CONFIG_PM_SLEEP)) >> + register_syscore_ops(&tcu_pm_ops); >> +} =