From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4815C433FE for ; Wed, 12 Jan 2022 22:08:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233906AbiALWIT (ORCPT ); Wed, 12 Jan 2022 17:08:19 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:42080 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232589AbiALWIS (ORCPT ); Wed, 12 Jan 2022 17:08:18 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1FF1661AEA; Wed, 12 Jan 2022 22:08:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3484AC36AE9; Wed, 12 Jan 2022 22:08:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642025297; bh=3MwDi+jdG5sFiEGXGM6lIRrnnJsRtasqtYq1nft1+jM=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=axTCsbvVDh4fI3MOPa1eFLc2n/hra+/lakzMnx5WWzs9OWIF6V/7ao5RWj2dQFtwz 9f6GSr0rqo5pDIPRKT7GVo85mc1QQ5rpQFK6Lrl7J3Jw0f26dfC9ADZeE0QJVF1jAC 9+FpBaeqNTOttToek8AKzDy4ji4V0FUhX+QV/hbq09dCJNFPxmomNQ1i2nyIEz0O7J wyhAnsvZOSbYxG+obT5M4iU9JRIUq66zVcls/Lk6FgcK1z7DNhwkXuyxHDJDGtWD1c 7FL2ZAbwjPUuy3Vu2mmOaxqjzgZ/nyjm8g3AS1RBgZyH8DiNb4b3qbwY4hlAriIaux 6SWiQ6Cp5hDMw== Date: Wed, 12 Jan 2022 16:08:15 -0600 From: Bjorn Helgaas To: Marek =?iso-8859-1?Q?Beh=FAn?= Cc: devicetree@vger.kernel.org, robh+dt@kernel.org, linux-pci@vger.kernel.org, Pali =?iso-8859-1?Q?Roh=E1r?= Subject: Re: [PATCH dt + pci 2/2] PCI: Add function for parsing `slot-power-limit-milliwatt` DT property Message-ID: <20220112220815.GA287870@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20211031150706.27873-2-kabel@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Sun, Oct 31, 2021 at 04:07:06PM +0100, Marek Behún wrote: > From: Pali Rohár > > Add function of_pci_get_slot_power_limit(), which parses the > `slot-power-limit-milliwatt` DT property, returning the value in > milliwatts and in format ready for the PCIe Slot Capabilities Register. > > Signed-off-by: Pali Rohár > Signed-off-by: Marek Behún Acked-by: Bjorn Helgaas Do we have a caller of of_pci_get_slot_power_limit() yet? I didn't see one from a quick look (https://lore.kernel.org/linux-pci/?q=b%3Aof_pci_get_slot_power_limit). Let's merge this when we have a user for it. > --- > drivers/pci/of.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++ > drivers/pci/pci.h | 15 +++++++++++ > 2 files changed, 79 insertions(+) > > diff --git a/drivers/pci/of.c b/drivers/pci/of.c > index d84381ce82b5..9c1a38d5dd99 100644 > --- a/drivers/pci/of.c > +++ b/drivers/pci/of.c > @@ -627,3 +627,67 @@ int of_pci_get_max_link_speed(struct device_node *node) > return max_link_speed; > } > EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed); > + > +/** > + * of_pci_get_slot_power_limit - Parses the "slot-power-limit-milliwatt" > + * property. > + * > + * @node: device tree node with the slot power limit information > + * @slot_power_limit_value: pointer where the value should be stored in PCIe > + * Slot Capabilities Register format > + * @slot_power_limit_scale: pointer where the scale should be stored in PCIe > + * Slot Capabilities Register format > + * > + * Returns the slot power limit in milliwatts and if @slot_power_limit_value > + * and @slot_power_limit_scale pointers are non-NULL, fills in the value and > + * scale in format used by PCIe Slot Capabilities Register. > + * > + * If the property is not found or is invalid, returns 0. > + */ > +u32 of_pci_get_slot_power_limit(struct device_node *node, > + u8 *slot_power_limit_value, > + u8 *slot_power_limit_scale) > +{ > + u32 slot_power_limit; > + u8 value, scale; > + > + if (of_property_read_u32(node, "slot-power-limit-milliwatt", > + &slot_power_limit)) > + slot_power_limit = 0; > + > + /* Calculate Slot Power Limit Value and Slot Power Limit Scale */ > + if (slot_power_limit == 0) { > + value = 0x00; > + scale = 0; > + } else if (slot_power_limit <= 255) { > + value = slot_power_limit; > + scale = 3; > + } else if (slot_power_limit <= 255*10) { > + value = slot_power_limit / 10; > + scale = 2; > + } else if (slot_power_limit <= 255*100) { > + value = slot_power_limit / 100; > + scale = 1; > + } else if (slot_power_limit <= 239*1000) { > + value = slot_power_limit / 1000; > + scale = 0; > + } else if (slot_power_limit <= 250*1000) { > + value = 0xF0; > + scale = 0; > + } else if (slot_power_limit <= 275*1000) { > + value = 0xF1; > + scale = 0; > + } else { > + value = 0xF2; > + scale = 0; > + } > + > + if (slot_power_limit_value) > + *slot_power_limit_value = value; > + > + if (slot_power_limit_scale) > + *slot_power_limit_scale = scale; > + > + return slot_power_limit; > +} > +EXPORT_SYMBOL_GPL(of_pci_get_slot_power_limit); > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 1cce56c2aea0..9352278141be 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -665,6 +665,9 @@ struct device_node; > int of_pci_parse_bus_range(struct device_node *node, struct resource *res); > int of_get_pci_domain_nr(struct device_node *node); > int of_pci_get_max_link_speed(struct device_node *node); > +u32 of_pci_get_slot_power_limit(struct device_node *node, > + u8 *slot_power_limit_value, > + u8 *slot_power_limit_scale); > void pci_set_of_node(struct pci_dev *dev); > void pci_release_of_node(struct pci_dev *dev); > void pci_set_bus_of_node(struct pci_bus *bus); > @@ -691,6 +694,18 @@ of_pci_get_max_link_speed(struct device_node *node) > return -EINVAL; > } > > +static inline u32 > +of_pci_get_slot_power_limit(struct device_node *node, > + u8 *slot_power_limit_value, > + u8 *slot_power_limit_scale) > +{ > + if (slot_power_limit_value) > + *slot_power_limit_value = 0; > + if (slot_power_limit_scale) > + *slot_power_limit_scale = 0; > + return 0; > +} > + > static inline void pci_set_of_node(struct pci_dev *dev) { } > static inline void pci_release_of_node(struct pci_dev *dev) { } > static inline void pci_set_bus_of_node(struct pci_bus *bus) { } > -- > 2.32.0 >