[2/3] ARM: bcm2835: add rpi power domain driver

Message ID	1447956490-22930-3-git-send-email-alex.aring@gmail.com (mailing list archive)
State	Not Applicable, archived
Headers	show Return-Path: <linux-pm-owner@kernel.org> From: Alexander Aring <alex.aring@gmail.com> To: linux-rpi-kernel@lists.infradead.org Cc: robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, swarren@wwwdotorg.org, lee@kernel.org, eric@anholt.net, linux@arm.linux.org.uk, f.fainelli@gmail.com, rjui@broadcom.com, sbranden@broadcom.com, rjw@rjwysocki.net, khilman@kernel.org, ulf.hansson@linaro.org, len.brown@intel.com, pavel@ucw.cz, gregkh@linuxfoundation.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, bcm-kernel-feedback-list@broadcom.com, linux-pm@vger.kernel.org, kernel@pengutronix.de, Alexander Aring <alex.aring@gmail.com> Subject: [PATCH 2/3] ARM: bcm2835: add rpi power domain driver Date: Thu, 19 Nov 2015 19:08:09 +0100 Message-Id: <1447956490-22930-3-git-send-email-alex.aring@gmail.com> In-Reply-To: <1447956490-22930-1-git-send-email-alex.aring@gmail.com> References: <1447956490-22930-1-git-send-email-alex.aring@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-pm-owner@vger.kernel.org Precedence: bulk

diff --git a/arch/arm/boot/dts/bcm2835-rpi.dtsi b/arch/arm/boot/dts/bcm2835-rpi.dtsi index 3572f03..f828202 100644 --- a/arch/arm/boot/dts/bcm2835-rpi.dtsi +++ b/arch/arm/boot/dts/bcm2835-rpi.dtsi @@ -1,3 +1,4 @@ +#include <dt-bindings/arm/raspberrypi-power.h> #include "bcm2835.dtsi" / { @@ -20,6 +21,12 @@ compatible = "raspberrypi,bcm2835-firmware"; mboxes = <&mailbox>; }; + + power: power { + compatible = "raspberrypi,bcm2835-power"; + firmware = <&firmware>; + #power-domain-cells = <1>; + }; }; }; @@ -60,3 +67,7 @@ status = "okay"; bus-width = <4>; }; + +&usb { + power-domains = <&power RPI_POWER_DOMAIN_USB>; +}; diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi index aef64de..6d62af0 100644 --- a/arch/arm/boot/dts/bcm2835.dtsi +++ b/arch/arm/boot/dts/bcm2835.dtsi @@ -177,7 +177,7 @@ status = "disabled"; }; - usb@7e980000 { + usb: usb@7e980000 { compatible = "brcm,bcm2835-usb"; reg = <0x7e980000 0x10000>; interrupts = <1 9>; diff --git a/arch/arm/mach-bcm/Kconfig b/arch/arm/mach-bcm/Kconfig index 8c53c55..20479d7 100644 --- a/arch/arm/mach-bcm/Kconfig +++ b/arch/arm/mach-bcm/Kconfig @@ -134,6 +134,16 @@ config ARCH_BCM2835 This enables support for the Broadcom BCM2835 SoC. This SoC is used in the Raspberry Pi and Roku 2 devices. +config RASPBERRYPI_POWER + bool "Raspberry Pi power domain driver" + depends on ARCH_BCM2835 + depends on RASPBERRYPI_FIRMWARE + select PM_GENERIC_DOMAINS if PM + select PM_GENERIC_DOMAINS_OF if PM + help + This enables support for the RPi power domains which can be enabled + or disabled via the RPi firmware. + config ARCH_BCM_63XX bool "Broadcom BCM63xx DSL SoC" if ARCH_MULTI_V7 depends on MMU diff --git a/arch/arm/mach-bcm/Makefile b/arch/arm/mach-bcm/Makefile index 892261f..fec2d6b 100644 --- a/arch/arm/mach-bcm/Makefile +++ b/arch/arm/mach-bcm/Makefile @@ -36,6 +36,7 @@ endif # BCM2835 obj-$(CONFIG_ARCH_BCM2835) += board_bcm2835.o +obj-$(CONFIG_RASPBERRYPI_POWER) += raspberrypi-power.o # BCM5301X obj-$(CONFIG_ARCH_BCM_5301X) += bcm_5301x.o diff --git a/arch/arm/mach-bcm/raspberrypi-power.c b/arch/arm/mach-bcm/raspberrypi-power.c new file mode 100644 index 0000000..ee77e45 --- /dev/null +++ b/arch/arm/mach-bcm/raspberrypi-power.c @@ -0,0 +1,180 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Authors: + * (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de> + * Eric Anholt <eric@anholt.net> + */ + +#include <linux/module.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/pm_domain.h> +#include <dt-bindings/arm/raspberrypi-power.h> +#include <soc/bcm2835/raspberrypi-firmware.h> + +#define RPI_POWER_DOMAIN(_domain, _name) \ + [_domain] = { \ + .domain = _domain, \ + .enabled = true, \ + .base = { \ + .name = _name, \ + .power_off = rpi_domain_off, \ + .power_on = rpi_domain_on, \ + }, \ + } + +struct rpi_power_domain { + u32 domain; + bool enabled; + struct generic_pm_domain base; +}; + +struct rpi_power_domain_packet { + u32 domain; + u32 on; +} __packet; + +static struct rpi_firmware *fw; +static struct genpd_onecell_data rpi_genpd_xlate; + +/* + * Asks the firmware to enable or disable power on a specific power + * domain. + */ +static int rpi_firmware_set_power(u32 domain, bool on) +{ + struct rpi_power_domain_packet packet; + + packet.domain = domain; + packet.on = on; + return rpi_firmware_property(fw, RPI_FIRMWARE_SET_POWER_STATE, &packet, + sizeof(packet)); +} + +/* Asks the firmware to if power is on for a specific power domain. */ +static int rpi_firmware_power_is_on(u32 domain) +{ + struct rpi_power_domain_packet packet; + int ret; + + packet.domain = domain; + ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_POWER_STATE, &packet, + sizeof(packet)); + if (ret < 0) + return ret; + + return packet.on & BIT(0); +} + +static int rpi_domain_off(struct generic_pm_domain *domain) +{ + struct rpi_power_domain *rpi_domain = + container_of(domain, struct rpi_power_domain, base); + + return rpi_firmware_set_power(rpi_domain->domain, false); +} + +static int rpi_domain_on(struct generic_pm_domain *domain) +{ + struct rpi_power_domain *rpi_domain = + container_of(domain, struct rpi_power_domain, base); + + return rpi_firmware_set_power(rpi_domain->domain, true); +} + +static struct rpi_power_domain rpi_power_domains[] = { + RPI_POWER_DOMAIN(RPI_POWER_DOMAIN_USB, "USB"), +}; + +static int rpi_power_probe(struct platform_device *pdev) +{ + struct device_node *fw_np; + struct device *dev = &pdev->dev; + struct generic_pm_domain **power_domains; + int i, ret, num_domains = ARRAY_SIZE(rpi_power_domains); + + fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0); + if (!fw_np) { + dev_err(&pdev->dev, "no firmware node\n"); + return -ENODEV; + } + + fw = rpi_firmware_get(fw_np); + if (!fw) + return -EPROBE_DEFER; + + power_domains = devm_kzalloc(dev, sizeof(*power_domains) * num_domains, + GFP_KERNEL); + if (!power_domains) + return -ENOMEM; + + rpi_genpd_xlate.domains = power_domains; + rpi_genpd_xlate.num_domains = num_domains; + + for (i = 0; i < num_domains; i++) { + bool is_off; + + if (!rpi_power_domains[i].enabled) + continue; + + /* get the initial state */ + ret = rpi_firmware_power_is_on(rpi_power_domains[i].domain); + if (ret < 0) + goto uninit_pm; + + /* pm_genpd_init needs is_off, invert the logic here */ + is_off = !ret; + pm_genpd_init(&rpi_power_domains[i].base, NULL, is_off); + /* let power_domains array know about the registered pm */ + power_domains[i] = &rpi_power_domains[i].base; + } + + ret = of_genpd_add_provider_onecell(dev->of_node, &rpi_genpd_xlate); + if (ret < 0) + goto uninit_pm; + + return 0; + +uninit_pm: + for (i = 0; i < num_domains; i++) + pm_genpd_uninit(power_domains[i]); + + return ret; +} + +static int rpi_power_remove(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + int i; + + for (i = 0; i < rpi_genpd_xlate.num_domains; i++) + pm_genpd_uninit(rpi_genpd_xlate.domains[i]); + + of_genpd_del_provider(dev->of_node); + + return 0; +} + +static const struct of_device_id rpi_power_of_match[] = { + { .compatible = "raspberrypi,bcm2835-power", }, + {}, +}; +MODULE_DEVICE_TABLE(of, rpi_power_of_match); + +static struct platform_driver rpi_power_driver = { + .driver = { + .name = "raspberrypi-power", + .of_match_table = rpi_power_of_match, + }, + .probe = rpi_power_probe, + .remove = rpi_power_remove, +}; +module_platform_driver(rpi_power_driver); + +MODULE_AUTHOR("Alexander Aring <aar@pengutronix.de>"); +MODULE_AUTHOR("Eric Anholt <eric@anholt.net>"); +MODULE_DESCRIPTION("Raspberry Pi power domain driver"); +MODULE_LICENSE("GPL v2"); diff --git a/include/dt-bindings/arm/raspberrypi-power.h b/include/dt-bindings/arm/raspberrypi-power.h new file mode 100644 index 0000000..c2ffbebc --- /dev/null +++ b/include/dt-bindings/arm/raspberrypi-power.h @@ -0,0 +1,14 @@ +/* + * Copyright © 2015 Broadcom + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _DT_BINDINGS_ARM_BCM2835_RPI_POWER_H +#define _DT_BINDINGS_ARM_BCM2835_RPI_POWER_H + +#define RPI_POWER_DOMAIN_USB 3 + +#endif /* _DT_BINDINGS_ARM_BCM2835_RPI_POWER_H */

[2/3] ARM: bcm2835: add rpi power domain driver

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