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 6C982C433F5 for ; Fri, 22 Apr 2022 10:06:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1446403AbiDVKJL (ORCPT ); Fri, 22 Apr 2022 06:09:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46360 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1446197AbiDVKJF (ORCPT ); Fri, 22 Apr 2022 06:09:05 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 5882853737; Fri, 22 Apr 2022 03:06:12 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 06DF01477; Fri, 22 Apr 2022 03:06:12 -0700 (PDT) Received: from lpieralisi (unknown [10.57.12.153]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 50E6B3F766; Fri, 22 Apr 2022 03:06:10 -0700 (PDT) Date: Fri, 22 Apr 2022 11:06:04 +0100 From: Lorenzo Pieralisi To: Pali =?iso-8859-1?Q?Roh=E1r?= Cc: Bjorn Helgaas , Bjorn Helgaas , Rob Herring , Andrew Lunn , Thomas Petazzoni , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Marek =?iso-8859-1?Q?Beh=FAn?= , Russell King , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 3/4] PCI: Add function for parsing 'slot-power-limit-milliwatt' DT property Message-ID: <20220422100604.GA500@lpieralisi> References: <20220412094946.27069-4-pali@kernel.org> <20220413202433.GA688099@bhelgaas> <20220421201413.hwpfby4i5tvhwxqv@pali> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220421201413.hwpfby4i5tvhwxqv@pali> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 21, 2022 at 10:14:13PM +0200, Pali Rohár wrote: > On Wednesday 13 April 2022 15:24:33 Bjorn Helgaas wrote: > > On Tue, Apr 12, 2022 at 11:49:45AM +0200, Pali Rohár wrote: > > > 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 > > > Reviewed-by: Rob Herring > > > > Looks good to me! Thank you! > > > > Reviewed-by: Bjorn Helgaas > > Perfect! > > Lorenzo, is this patch series OK now for merging? Yes it is. I have a related question (ie how to check whether a binding has been accepted into the DT schema) but I will sort that out with Rob. Thanks, Lorenzo > > > --- > > > Changes in v4: > > > * Set 239 W when DT slot-power-limit-milliwatt is between 239 W and 250 W > > > * Fix returning power limit value > > > Changes in v3: > > > * Set 600 W when DT slot-power-limit-milliwatt > 600 W > > > Changes in v2: > > > * Added support for PCIe 6.0 slot power limit encodings > > > * Round down slot power limit value > > > --- > > > drivers/pci/of.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++ > > > drivers/pci/pci.h | 15 ++++++++++ > > > 2 files changed, 85 insertions(+) > > > > > > diff --git a/drivers/pci/of.c b/drivers/pci/of.c > > > index cb2e8351c2cc..6c1b81304665 100644 > > > --- a/drivers/pci/of.c > > > +++ b/drivers/pci/of.c > > > @@ -633,3 +633,73 @@ 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_mw; > > > + u8 value, scale; > > > + > > > + if (of_property_read_u32(node, "slot-power-limit-milliwatt", > > > + &slot_power_limit_mw)) > > > + slot_power_limit_mw = 0; > > > + > > > + /* Calculate Slot Power Limit Value and Slot Power Limit Scale */ > > > + if (slot_power_limit_mw == 0) { > > > + value = 0x00; > > > + scale = 0; > > > + } else if (slot_power_limit_mw <= 255) { > > > + value = slot_power_limit_mw; > > > + scale = 3; > > > + } else if (slot_power_limit_mw <= 255*10) { > > > + value = slot_power_limit_mw / 10; > > > + scale = 2; > > > + slot_power_limit_mw = slot_power_limit_mw / 10 * 10; > > > + } else if (slot_power_limit_mw <= 255*100) { > > > + value = slot_power_limit_mw / 100; > > > + scale = 1; > > > + slot_power_limit_mw = slot_power_limit_mw / 100 * 100; > > > + } else if (slot_power_limit_mw <= 239*1000) { > > > + value = slot_power_limit_mw / 1000; > > > + scale = 0; > > > + slot_power_limit_mw = slot_power_limit_mw / 1000 * 1000; > > > + } else if (slot_power_limit_mw < 250*1000) { > > > + value = 0xEF; > > > + scale = 0; > > > + slot_power_limit_mw = 239*1000; > > > + } else if (slot_power_limit_mw <= 600*1000) { > > > + value = 0xF0 + (slot_power_limit_mw / 1000 - 250) / 25; > > > + scale = 0; > > > + slot_power_limit_mw = slot_power_limit_mw / (1000*25) * (1000*25); > > > + } else { > > > + value = 0xFE; > > > + scale = 0; > > > + slot_power_limit_mw = 600*1000; > > > + } > > > + > > > + if (slot_power_limit_value) > > > + *slot_power_limit_value = value; > > > + > > > + if (slot_power_limit_scale) > > > + *slot_power_limit_scale = scale; > > > + > > > + return slot_power_limit_mw; > > > +} > > > +EXPORT_SYMBOL_GPL(of_pci_get_slot_power_limit); > > > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > > > index 3d60cabde1a1..e10cdec6c56e 100644 > > > --- a/drivers/pci/pci.h > > > +++ b/drivers/pci/pci.h > > > @@ -627,6 +627,9 @@ 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); > > > @@ -653,6 +656,18 @@ 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) { } > > > -- > > > 2.20.1 > > > > > > > > > _______________________________________________ > > > linux-arm-kernel mailing list > > > linux-arm-kernel@lists.infradead.org > > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel