From: Bjorn Helgaas <helgaas@kernel.org> To: "Pali Rohár" <pali@kernel.org> Cc: "Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>, "Bjorn Helgaas" <bhelgaas@google.com>, "Rob Herring" <robh+dt@kernel.org>, "Andrew Lunn" <andrew@lunn.ch>, "Thomas Petazzoni" <thomas.petazzoni@bootlin.com>, "Krzysztof Wilczyński" <kw@linux.com>, "Marek Behún" <kabel@kernel.org>, "Russell King" <rmk+kernel@armlinux.org.uk>, 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 Date: Wed, 13 Apr 2022 15:24:33 -0500 [thread overview] Message-ID: <20220413202433.GA688099@bhelgaas> (raw) In-Reply-To: <20220412094946.27069-4-pali@kernel.org> 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 <pali@kernel.org> > Signed-off-by: Marek Behún <kabel@kernel.org> > Reviewed-by: Rob Herring <robh@kernel.org> Looks good to me! Thank you! Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> > --- > 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
WARNING: multiple messages have this Message-ID (diff)
From: Bjorn Helgaas <helgaas@kernel.org> To: "Pali Rohár" <pali@kernel.org> Cc: "Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>, "Bjorn Helgaas" <bhelgaas@google.com>, "Rob Herring" <robh+dt@kernel.org>, "Andrew Lunn" <andrew@lunn.ch>, "Thomas Petazzoni" <thomas.petazzoni@bootlin.com>, "Krzysztof Wilczyński" <kw@linux.com>, "Marek Behún" <kabel@kernel.org>, "Russell King" <rmk+kernel@armlinux.org.uk>, 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 Date: Wed, 13 Apr 2022 15:24:33 -0500 [thread overview] Message-ID: <20220413202433.GA688099@bhelgaas> (raw) In-Reply-To: <20220412094946.27069-4-pali@kernel.org> 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 <pali@kernel.org> > Signed-off-by: Marek Behún <kabel@kernel.org> > Reviewed-by: Rob Herring <robh@kernel.org> Looks good to me! Thank you! Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> > --- > 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-04-13 20:24 UTC|newest] Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-04-12 9:49 [PATCH v5 0/4] PCI: mvebu: Slot support Pali Rohár 2022-04-12 9:49 ` Pali Rohár 2022-04-12 9:49 ` [PATCH v5 1/4] PCI: Add PCI_EXP_SLTCTL_ASPL_DISABLE macro Pali Rohár 2022-04-12 9:49 ` Pali Rohár 2022-04-12 9:49 ` [PATCH v5 2/4] dt-bindings: Add 'slot-power-limit-milliwatt' PCIe port property Pali Rohár 2022-04-12 9:49 ` Pali Rohár 2022-04-12 9:49 ` [PATCH v5 3/4] PCI: Add function for parsing 'slot-power-limit-milliwatt' DT property Pali Rohár 2022-04-12 9:49 ` Pali Rohár 2022-04-13 20:24 ` Bjorn Helgaas [this message] 2022-04-13 20:24 ` Bjorn Helgaas 2022-04-21 20:14 ` Pali Rohár 2022-04-21 20:14 ` Pali Rohár 2022-04-22 10:06 ` Lorenzo Pieralisi 2022-04-22 10:06 ` Lorenzo Pieralisi 2022-04-12 9:49 ` [PATCH v5 4/4] PCI: mvebu: Add support for sending Set_Slot_Power_Limit message Pali Rohár 2022-04-12 9:49 ` Pali Rohár 2022-04-25 9:59 ` (subset) [PATCH v5 0/4] PCI: mvebu: Slot support Lorenzo Pieralisi 2022-04-25 9:59 ` Lorenzo Pieralisi
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