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Diffstat (limited to '')
| -rw-r--r-- | arch/x86/platform/intel-mid/pwr.c | 488 |
1 files changed, 488 insertions, 0 deletions
diff --git a/arch/x86/platform/intel-mid/pwr.c b/arch/x86/platform/intel-mid/pwr.c new file mode 100644 index 000000000..49ec5b94c --- /dev/null +++ b/arch/x86/platform/intel-mid/pwr.c @@ -0,0 +1,488 @@ +/* + * Intel MID Power Management Unit (PWRMU) device driver + * + * Copyright (C) 2016, Intel Corporation + * + * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com> + * + * 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 <linux/delay.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/mutex.h> +#include <linux/pci.h> + +#include <asm/intel-mid.h> + +/* 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) + +/* System states */ +#define PM_CMD_SYS_STATE_S5 (5 << 16) + +/* Trigger variants */ +#define PM_CMD_CFG_TRIGGER_NC (3 << 19) + +/* Message to wait for TRIGGER_NC case */ +#define TRIGGER_NC_MSG_2 (2 << 22) + +/* 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; +} + +pci_power_t intel_mid_pci_get_power_state(struct pci_dev *pdev) +{ + struct mid_pwr *pwr = midpwr; + int id, reg, bit; + u32 power; + + if (!pwr || !pwr->available) + return PCI_UNKNOWN; + + id = intel_mid_pwr_get_lss_id(pdev); + if (id < 0) + return PCI_UNKNOWN; + + reg = (id * LSS_PWS_BITS) / 32; + bit = (id * LSS_PWS_BITS) % 32; + power = mid_pwr_get_state(pwr, reg); + return (__force pci_power_t)((power >> bit) & 3); +} + +void intel_mid_pwr_power_off(void) +{ + struct mid_pwr *pwr = midpwr; + u32 cmd = PM_CMD_SYS_STATE_S5 | + PM_CMD_CMD(CMD_SET_CFG) | + PM_CMD_CM_TRIGGER | + PM_CMD_CFG_TRIGGER_NC | + TRIGGER_NC_MSG_2; + + /* Send command to SCU */ + writel(cmd, pwr->regs + PM_CMD); + mid_pwr_wait(pwr); +} + +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, const u32 *states) +{ + 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, states[0]); + mid_pwr_set_state(pwr, 1, states[1]); + mid_pwr_set_state(pwr, 2, states[2]); + mid_pwr_set_state(pwr, 3, states[3]); + + /* 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 int pnw_set_initial_state(struct mid_pwr *pwr) +{ + /* On Penwell SRAM must stay powered on */ + static const u32 states[] = { + 0xf00fffff, /* PM_SSC(0) */ + 0xffffffff, /* PM_SSC(1) */ + 0xffffffff, /* PM_SSC(2) */ + 0xffffffff, /* PM_SSC(3) */ + }; + return mid_set_initial_state(pwr, states); +} + +static int tng_set_initial_state(struct mid_pwr *pwr) +{ + static const u32 states[] = { + 0xffffffff, /* PM_SSC(0) */ + 0xffffffff, /* PM_SSC(1) */ + 0xffffffff, /* PM_SSC(2) */ + 0xffffffff, /* PM_SSC(3) */ + }; + return mid_set_initial_state(pwr, states); +} + +static const struct mid_pwr_device_info pnw_info = { + .set_initial_state = pnw_set_initial_state, +}; + +static const struct mid_pwr_device_info tng_info = { + .set_initial_state = tng_set_initial_state, +}; + +/* This table should be in sync with the one in drivers/pci/pci-mid.c */ +static const struct pci_device_id mid_pwr_pci_ids[] = { + { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_PENWELL), (kernel_ulong_t)&pnw_info }, + { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_TANGIER), (kernel_ulong_t)&tng_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); |