From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934975AbdJQKKL (ORCPT ); Tue, 17 Oct 2017 06:10:11 -0400 Received: from mail-wm0-f49.google.com ([74.125.82.49]:54659 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760651AbdJQKJ6 (ORCPT ); Tue, 17 Oct 2017 06:09:58 -0400 X-Google-Smtp-Source: AOwi7QAeTFzQbJV4a055w+A7TxCMwezTPJ/v+niTctZyjWn9JI8ToHE7j8jvBofmtNE+1Yybb8U4yQ== Subject: Re: [PATCH] reset: meson: add level reset support for GX SoC family To: Philipp Zabel Cc: linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <1508167573-17396-1-git-send-email-narmstrong@baylibre.com> <1508234898.6854.6.camel@pengutronix.de> From: Neil Armstrong Organization: Baylibre Message-ID: <489c147c-9972-68ef-3475-322f56d4a620@baylibre.com> Date: Tue, 17 Oct 2017 12:09:54 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <1508234898.6854.6.camel@pengutronix.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17/10/2017 12:08, Philipp Zabel wrote: > Hi Neil, > > On Mon, 2017-10-16 at 17:26 +0200, Neil Armstrong wrote: >> The Amlogic GX SoC family embeds alternate registers to drive the reset >> levels next to the pulse registers. >> >> This patch adds support for level reset handling on the GX family only. >> >> The Meson8 family has an alternate way to handle level reset. >> >> Signed-off-by: Neil Armstrong > > thank you for the patch, comments below: > >> --- >> drivers/reset/reset-meson.c | 57 +++++++++++++++++++++++++++++++++++++++++---- >> 1 file changed, 53 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/reset/reset-meson.c b/drivers/reset/reset-meson.c >> index a8b915e..d55e440 100644 >> --- a/drivers/reset/reset-meson.c >> +++ b/drivers/reset/reset-meson.c >> @@ -62,9 +62,11 @@ >> #include >> #include >> #include >> +#include >> >> #define REG_COUNT 8 >> #define BITS_PER_REG 32 >> +#define LEVEL_OFFSET 0x7c >> >> struct meson_reset { >> void __iomem *reg_base; >> @@ -88,18 +90,61 @@ static int meson_reset_reset(struct reset_controller_dev *rcdev, >> return 0; >> } >> >> -static const struct reset_control_ops meson_reset_ops = { >> +static int meson_reset_level(struct reset_controller_dev *rcdev, >> + unsigned long id, bool assert) >> +{ >> + struct meson_reset *data = >> + container_of(rcdev, struct meson_reset, rcdev); >> + unsigned int bank = id / BITS_PER_REG; >> + unsigned int offset = id % BITS_PER_REG; >> + void __iomem *reg_addr = data->reg_base + LEVEL_OFFSET + (bank << 2); >> + u32 reg; >> + >> + if (bank >= REG_COUNT) >> + return -EINVAL; > > This check is not necessary. The same check is in meson_reset_reset, > which I didn't notice last time. > > of_reset_simple_xlate, the default rcdev->of_xlate implementation, > already guarantees id < rcdev->nr_resets. And since nr_resets is set to > REG_COUNT * BITS_PER_REG, we know that id < REG_COUNT * BITS_PER_REG and > thus bank <= id / BITS_PER_REG < REG_COUNT. Ok will remove. > >> + reg = readl(reg_addr); >> + if (assert) >> + writel(reg & ~BIT(offset), reg_addr); >> + else >> + writel(reg | BIT(offset), reg_addr); > > These read-modify-write operations must be protected by a spinlock. Ok will add > >> + >> + return 0; >> +} >> + >> +static int meson_reset_assert(struct reset_controller_dev *rcdev, >> + unsigned long id) >> +{ >> + return meson_reset_level(rcdev, id, true); >> +} >> + >> +static int meson_reset_deassert(struct reset_controller_dev *rcdev, >> + unsigned long id) >> +{ >> + return meson_reset_level(rcdev, id, false); >> +} >> + >> +static const struct reset_control_ops meson_reset_meson8_ops = { >> + .reset = meson_reset_reset, >> +}; >> + >> +static const struct reset_control_ops meson_reset_gx_ops = { >> .reset = meson_reset_reset, >> + .assert = meson_reset_assert, >> + .deassert = meson_reset_deassert, >> }; >> >> static const struct of_device_id meson_reset_dt_ids[] = { >> - { .compatible = "amlogic,meson8b-reset", }, >> - { .compatible = "amlogic,meson-gxbb-reset", }, >> + { .compatible = "amlogic,meson8b-reset", >> + .data = (void *) &meson_reset_meson8_ops, }, >> + { .compatible = "amlogic,meson-gxbb-reset", >> + .data = (void *) &meson_reset_gx_ops, }, >> { /* sentinel */ }, >> }; > > of_device_id.data ist const void *, so there is no need to cast here. Ok will remove then > >> static int meson_reset_probe(struct platform_device *pdev) >> { >> + const struct reset_control_ops *ops; >> struct meson_reset *data; >> struct resource *res; >> >> @@ -107,6 +152,10 @@ static int meson_reset_probe(struct platform_device *pdev) >> if (!data) >> return -ENOMEM; >> >> + ops = of_device_get_match_data(&pdev->dev); >> + if (!ops) >> + return -EINVAL; >> + >> res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> data->reg_base = devm_ioremap_resource(&pdev->dev, res); >> if (IS_ERR(data->reg_base)) >> @@ -116,7 +165,7 @@ static int meson_reset_probe(struct platform_device *pdev) >> >> data->rcdev.owner = THIS_MODULE; >> data->rcdev.nr_resets = REG_COUNT * BITS_PER_REG; >> - data->rcdev.ops = &meson_reset_ops; >> + data->rcdev.ops = ops; >> data->rcdev.of_node = pdev->dev.of_node; >> >> return devm_reset_controller_register(&pdev->dev, &data->rcdev); > > regards > Philipp > Thanks, Neil