/* * Intel MID Power Management Unit (PWRMU) device driver * * Copyright (C) 2016, Intel Corporation * * Author: Andy Shevchenko * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * Intel MID Power Management Unit device driver handles the South Complex PCI * devices such as GPDMA, SPI, I2C, PWM, and so on. By default PCI core * modifies bits in PMCSR register in the PCI configuration space. This is not * enough on some SoCs like Intel Tangier. In such case PCI core sets a new * power state of the device in question through a PM hook registered in struct * pci_platform_pm_ops (see drivers/pci/pci-mid.c). */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include /* Registers */ #define PM_STS 0x00 #define PM_CMD 0x04 #define PM_ICS 0x08 #define PM_WKC(x) (0x10 + (x) * 4) #define PM_WKS(x) (0x18 + (x) * 4) #define PM_SSC(x) (0x20 + (x) * 4) #define PM_SSS(x) (0x30 + (x) * 4) /* Bits in PM_STS */ #define PM_STS_BUSY (1 << 8) /* Bits in PM_CMD */ #define PM_CMD_CMD(x) ((x) << 0) #define PM_CMD_IOC (1 << 8) #define PM_CMD_CM_NOP (0 << 9) #define PM_CMD_CM_IMMEDIATE (1 << 9) #define PM_CMD_CM_DELAY (2 << 9) #define PM_CMD_CM_TRIGGER (3 << 9) #define PM_CMD_D3cold (1 << 21) /* List of commands */ #define CMD_SET_CFG 0x01 /* Bits in PM_ICS */ #define PM_ICS_INT_STATUS(x) ((x) & 0xff) #define PM_ICS_IE (1 << 8) #define PM_ICS_IP (1 << 9) #define PM_ICS_SW_INT_STS (1 << 10) /* List of interrupts */ #define INT_INVALID 0 #define INT_CMD_COMPLETE 1 #define INT_CMD_ERR 2 #define INT_WAKE_EVENT 3 #define INT_LSS_POWER_ERR 4 #define INT_S0iX_MSG_ERR 5 #define INT_NO_C6 6 #define INT_TRIGGER_ERR 7 #define INT_INACTIVITY 8 /* South Complex devices */ #define LSS_MAX_SHARED_DEVS 4 #define LSS_MAX_DEVS 64 #define LSS_WS_BITS 1 /* wake state width */ #define LSS_PWS_BITS 2 /* power state width */ /* Supported device IDs */ #define PCI_DEVICE_ID_PENWELL 0x0828 #define PCI_DEVICE_ID_TANGIER 0x11a1 struct mid_pwr_dev { struct pci_dev *pdev; pci_power_t state; }; struct mid_pwr { struct device *dev; void __iomem *regs; int irq; bool available; struct mutex lock; struct mid_pwr_dev lss[LSS_MAX_DEVS][LSS_MAX_SHARED_DEVS]; }; static struct mid_pwr *midpwr; static u32 mid_pwr_get_state(struct mid_pwr *pwr, int reg) { return readl(pwr->regs + PM_SSS(reg)); } static void mid_pwr_set_state(struct mid_pwr *pwr, int reg, u32 value) { writel(value, pwr->regs + PM_SSC(reg)); } static void mid_pwr_set_wake(struct mid_pwr *pwr, int reg, u32 value) { writel(value, pwr->regs + PM_WKC(reg)); } static void mid_pwr_interrupt_disable(struct mid_pwr *pwr) { writel(~PM_ICS_IE, pwr->regs + PM_ICS); } static bool mid_pwr_is_busy(struct mid_pwr *pwr) { return !!(readl(pwr->regs + PM_STS) & PM_STS_BUSY); } /* Wait 500ms that the latest PWRMU command finished */ static int mid_pwr_wait(struct mid_pwr *pwr) { unsigned int count = 500000; bool busy; do { busy = mid_pwr_is_busy(pwr); if (!busy) return 0; udelay(1); } while (--count); return -EBUSY; } static int mid_pwr_wait_for_cmd(struct mid_pwr *pwr, u8 cmd) { writel(PM_CMD_CMD(cmd) | PM_CMD_CM_IMMEDIATE, pwr->regs + PM_CMD); return mid_pwr_wait(pwr); } static int __update_power_state(struct mid_pwr *pwr, int reg, int bit, int new) { int curstate; u32 power; int ret; /* Check if the device is already in desired state */ power = mid_pwr_get_state(pwr, reg); curstate = (power >> bit) & 3; if (curstate == new) return 0; /* Update the power state */ mid_pwr_set_state(pwr, reg, (power & ~(3 << bit)) | (new << bit)); /* Send command to SCU */ ret = mid_pwr_wait_for_cmd(pwr, CMD_SET_CFG); if (ret) return ret; /* Check if the device is already in desired state */ power = mid_pwr_get_state(pwr, reg); curstate = (power >> bit) & 3; if (curstate != new) return -EAGAIN; return 0; } static pci_power_t __find_weakest_power_state(struct mid_pwr_dev *lss, struct pci_dev *pdev, pci_power_t state) { pci_power_t weakest = PCI_D3hot; unsigned int j; /* Find device in cache or first free cell */ for (j = 0; j < LSS_MAX_SHARED_DEVS; j++) { if (lss[j].pdev == pdev || !lss[j].pdev) break; } /* Store the desired state in cache */ if (j < LSS_MAX_SHARED_DEVS) { lss[j].pdev = pdev; lss[j].state = state; } else { dev_WARN(&pdev->dev, "No room for device in PWRMU LSS cache\n"); weakest = state; } /* Find the power state we may use */ for (j = 0; j < LSS_MAX_SHARED_DEVS; j++) { if (lss[j].state < weakest) weakest = lss[j].state; } return weakest; } static int __set_power_state(struct mid_pwr *pwr, struct pci_dev *pdev, pci_power_t state, int id, int reg, int bit) { const char *name; int ret; state = __find_weakest_power_state(pwr->lss[id], pdev, state); name = pci_power_name(state); ret = __update_power_state(pwr, reg, bit, (__force int)state); if (ret) { dev_warn(&pdev->dev, "Can't set power state %s: %d\n", name, ret); return ret; } dev_vdbg(&pdev->dev, "Set power state %s\n", name); return 0; } static int mid_pwr_set_power_state(struct mid_pwr *pwr, struct pci_dev *pdev, pci_power_t state) { int id, reg, bit; int ret; id = intel_mid_pwr_get_lss_id(pdev); if (id < 0) return id; reg = (id * LSS_PWS_BITS) / 32; bit = (id * LSS_PWS_BITS) % 32; /* We support states between PCI_D0 and PCI_D3hot */ if (state < PCI_D0) state = PCI_D0; if (state > PCI_D3hot) state = PCI_D3hot; mutex_lock(&pwr->lock); ret = __set_power_state(pwr, pdev, state, id, reg, bit); mutex_unlock(&pwr->lock); return ret; } int intel_mid_pci_set_power_state(struct pci_dev *pdev, pci_power_t state) { struct mid_pwr *pwr = midpwr; int ret = 0; might_sleep(); if (pwr && pwr->available) ret = mid_pwr_set_power_state(pwr, pdev, state); dev_vdbg(&pdev->dev, "set_power_state() returns %d\n", ret); return 0; } EXPORT_SYMBOL_GPL(intel_mid_pci_set_power_state); int intel_mid_pwr_get_lss_id(struct pci_dev *pdev) { int vndr; u8 id; /* * Mapping to PWRMU index is kept in the Logical SubSystem ID byte of * Vendor capability. */ vndr = pci_find_capability(pdev, PCI_CAP_ID_VNDR); if (!vndr) return -EINVAL; /* Read the Logical SubSystem ID byte */ pci_read_config_byte(pdev, vndr + INTEL_MID_PWR_LSS_OFFSET, &id); if (!(id & INTEL_MID_PWR_LSS_TYPE)) return -ENODEV; id &= ~INTEL_MID_PWR_LSS_TYPE; if (id >= LSS_MAX_DEVS) return -ERANGE; return id; } static irqreturn_t mid_pwr_irq_handler(int irq, void *dev_id) { struct mid_pwr *pwr = dev_id; u32 ics; ics = readl(pwr->regs + PM_ICS); if (!(ics & PM_ICS_IP)) return IRQ_NONE; writel(ics | PM_ICS_IP, pwr->regs + PM_ICS); dev_warn(pwr->dev, "Unexpected IRQ: %#x\n", PM_ICS_INT_STATUS(ics)); return IRQ_HANDLED; } struct mid_pwr_device_info { int (*set_initial_state)(struct mid_pwr *pwr); }; static int mid_pwr_probe(struct pci_dev *pdev, const struct pci_device_id *id) { struct mid_pwr_device_info *info = (void *)id->driver_data; struct device *dev = &pdev->dev; struct mid_pwr *pwr; int ret; ret = pcim_enable_device(pdev); if (ret < 0) { dev_err(&pdev->dev, "error: could not enable device\n"); return ret; } ret = pcim_iomap_regions(pdev, 1 << 0, pci_name(pdev)); if (ret) { dev_err(&pdev->dev, "I/O memory remapping failed\n"); return ret; } pwr = devm_kzalloc(dev, sizeof(*pwr), GFP_KERNEL); if (!pwr) return -ENOMEM; pwr->dev = dev; pwr->regs = pcim_iomap_table(pdev)[0]; pwr->irq = pdev->irq; mutex_init(&pwr->lock); /* Disable interrupts */ mid_pwr_interrupt_disable(pwr); if (info && info->set_initial_state) { ret = info->set_initial_state(pwr); if (ret) dev_warn(dev, "Can't set initial state: %d\n", ret); } ret = devm_request_irq(dev, pdev->irq, mid_pwr_irq_handler, IRQF_NO_SUSPEND, pci_name(pdev), pwr); if (ret) return ret; pwr->available = true; midpwr = pwr; pci_set_drvdata(pdev, pwr); return 0; } static int mid_set_initial_state(struct mid_pwr *pwr) { unsigned int i, j; int ret; /* * Enable wake events. * * PWRMU supports up to 32 sources for wake up the system. Ungate them * all here. */ mid_pwr_set_wake(pwr, 0, 0xffffffff); mid_pwr_set_wake(pwr, 1, 0xffffffff); /* * Power off South Complex devices. * * There is a map (see a note below) of 64 devices with 2 bits per each * on 32-bit HW registers. The following calls set all devices to one * known initial state, i.e. PCI_D3hot. This is done in conjunction * with PMCSR setting in arch/x86/pci/intel_mid_pci.c. * * NOTE: The actual device mapping is provided by a platform at run * time using vendor capability of PCI configuration space. */ mid_pwr_set_state(pwr, 0, 0xffffffff); mid_pwr_set_state(pwr, 1, 0xffffffff); mid_pwr_set_state(pwr, 2, 0xffffffff); mid_pwr_set_state(pwr, 3, 0xffffffff); /* Send command to SCU */ ret = mid_pwr_wait_for_cmd(pwr, CMD_SET_CFG); if (ret) return ret; for (i = 0; i < LSS_MAX_DEVS; i++) { for (j = 0; j < LSS_MAX_SHARED_DEVS; j++) pwr->lss[i][j].state = PCI_D3hot; } return 0; } static const struct mid_pwr_device_info mid_info = { .set_initial_state = mid_set_initial_state, }; static const struct pci_device_id mid_pwr_pci_ids[] = { { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_PENWELL), (kernel_ulong_t)&mid_info }, { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_TANGIER), (kernel_ulong_t)&mid_info }, {} }; static struct pci_driver mid_pwr_pci_driver = { .name = "intel_mid_pwr", .probe = mid_pwr_probe, .id_table = mid_pwr_pci_ids, }; builtin_pci_driver(mid_pwr_pci_driver);