diff options
Diffstat (limited to 'drivers/soc/bcm/raspberrypi-power.c')
| -rw-r--r-- | drivers/soc/bcm/raspberrypi-power.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/drivers/soc/bcm/raspberrypi-power.c b/drivers/soc/bcm/raspberrypi-power.c new file mode 100644 index 000000000000..fe96a8b956fb --- /dev/null +++ b/drivers/soc/bcm/raspberrypi-power.c @@ -0,0 +1,247 @@ +/* (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de> + * + * 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: + * 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/power/raspberrypi-power.h> +#include <soc/bcm2835/raspberrypi-firmware.h> + +/* + * Firmware indices for the old power domains interface. Only a few + * of them were actually implemented. + */ +#define RPI_OLD_POWER_DOMAIN_USB 3 +#define RPI_OLD_POWER_DOMAIN_V3D 10 + +struct rpi_power_domain { + u32 domain; + bool enabled; + bool old_interface; + struct generic_pm_domain base; + struct rpi_firmware *fw; +}; + +struct rpi_power_domains { + bool has_new_interface; + struct genpd_onecell_data xlate; + struct rpi_firmware *fw; + struct rpi_power_domain domains[RPI_POWER_DOMAIN_COUNT]; +}; + +/* + * Packet definition used by RPI_FIRMWARE_SET_POWER_STATE and + * RPI_FIRMWARE_SET_DOMAIN_STATE + */ +struct rpi_power_domain_packet { + u32 domain; + u32 on; +} __packet; + +/* + * Asks the firmware to enable or disable power on a specific power + * domain. + */ +static int rpi_firmware_set_power(struct rpi_power_domain *rpi_domain, bool on) +{ + struct rpi_power_domain_packet packet; + + packet.domain = rpi_domain->domain; + packet.on = on; + return rpi_firmware_property(rpi_domain->fw, + rpi_domain->old_interface ? + RPI_FIRMWARE_SET_POWER_STATE : + RPI_FIRMWARE_SET_DOMAIN_STATE, + &packet, sizeof(packet)); +} + +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, 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, true); +} + +static void rpi_common_init_power_domain(struct rpi_power_domains *rpi_domains, + int xlate_index, const char *name) +{ + struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index]; + + dom->fw = rpi_domains->fw; + + dom->base.name = name; + dom->base.power_on = rpi_domain_on; + dom->base.power_off = rpi_domain_off; + + /* + * Treat all power domains as off at boot. + * + * The firmware itself may be keeping some domains on, but + * from Linux's perspective all we control is the refcounts + * that we give to the firmware, and we can't ask the firmware + * to turn off something that we haven't ourselves turned on. + */ + pm_genpd_init(&dom->base, NULL, true); + + rpi_domains->xlate.domains[xlate_index] = &dom->base; +} + +static void rpi_init_power_domain(struct rpi_power_domains *rpi_domains, + int xlate_index, const char *name) +{ + struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index]; + + if (!rpi_domains->has_new_interface) + return; + + /* The DT binding index is the firmware's domain index minus one. */ + dom->domain = xlate_index + 1; + + rpi_common_init_power_domain(rpi_domains, xlate_index, name); +} + +static void rpi_init_old_power_domain(struct rpi_power_domains *rpi_domains, + int xlate_index, int domain, + const char *name) +{ + struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index]; + + dom->old_interface = true; + dom->domain = domain; + + rpi_common_init_power_domain(rpi_domains, xlate_index, name); +} + +/* + * Detects whether the firmware supports the new power domains interface. + * + * The firmware doesn't actually return an error on an unknown tag, + * and just skips over it, so we do the detection by putting an + * unexpected value in the return field and checking if it was + * unchanged. + */ +static bool +rpi_has_new_domain_support(struct rpi_power_domains *rpi_domains) +{ + struct rpi_power_domain_packet packet; + int ret; + + packet.domain = RPI_POWER_DOMAIN_ARM; + packet.on = ~0; + + ret = rpi_firmware_property(rpi_domains->fw, + RPI_FIRMWARE_GET_DOMAIN_STATE, + &packet, sizeof(packet)); + + return ret == 0 && packet.on != ~0; +} + +static int rpi_power_probe(struct platform_device *pdev) +{ + struct device_node *fw_np; + struct device *dev = &pdev->dev; + struct rpi_power_domains *rpi_domains; + + rpi_domains = devm_kzalloc(dev, sizeof(*rpi_domains), GFP_KERNEL); + if (!rpi_domains) + return -ENOMEM; + + rpi_domains->xlate.domains = + devm_kzalloc(dev, sizeof(*rpi_domains->xlate.domains) * + RPI_POWER_DOMAIN_COUNT, GFP_KERNEL); + if (!rpi_domains->xlate.domains) + return -ENOMEM; + + rpi_domains->xlate.num_domains = RPI_POWER_DOMAIN_COUNT; + + fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0); + if (!fw_np) { + dev_err(&pdev->dev, "no firmware node\n"); + return -ENODEV; + } + + rpi_domains->fw = rpi_firmware_get(fw_np); + of_node_put(fw_np); + if (!rpi_domains->fw) + return -EPROBE_DEFER; + + rpi_domains->has_new_interface = + rpi_has_new_domain_support(rpi_domains); + + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C0, "I2C0"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, "I2C1"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, "I2C2"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER, + "VIDEO_SCALER"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, "VPU1"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, "HDMI"); + + /* + * Use the old firmware interface for USB power, so that we + * can turn it on even if the firmware hasn't been updated. + */ + rpi_init_old_power_domain(rpi_domains, RPI_POWER_DOMAIN_USB, + RPI_OLD_POWER_DOMAIN_USB, "USB"); + + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, "VEC"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, "JPEG"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, "H264"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, "V3D"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, "ISP"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, "UNICAM0"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, "UNICAM1"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, "CCP2RX"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, "CSI2"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, "CPI"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, "DSI0"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, "DSI1"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER, + "TRANSPOSER"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, "CCP2TX"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, "CDP"); + rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, "ARM"); + + of_genpd_add_provider_onecell(dev->of_node, &rpi_domains->xlate); + + platform_set_drvdata(pdev, rpi_domains); + + 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, +}; +builtin_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"); |