FreeBSD/Linux Kernel Cross Reference
sys/dev/cpufreq/ichss.c

     /*-
      * Copyright (c) 2004-2005 Nate Lawson (SDG)
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
      *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/bus.h>
    #include <sys/cpu.h>
    #include <sys/kernel.h>
    #include <sys/malloc.h>
    #include <sys/module.h>
    #include <sys/pcpu.h>
    #include <sys/sysctl.h>
    #include <sys/systm.h>
    
    #include <dev/pci/pcivar.h>
    #include <machine/bus.h>
    #include <machine/resource.h>
    #include <sys/rman.h>
    
    #include "cpufreq_if.h"
    
    /*
     * The SpeedStep ICH feature is a chipset-initiated voltage and frequency
     * transition available on the ICH2M, 3M, and 4M.  It is different from
     * the newer Pentium-M SpeedStep feature.  It offers only two levels of
     * frequency/voltage.  Often, the BIOS will select one of the levels via
     * SMM code during the power-on process (i.e., choose a lower level if the
     * system is off AC power.)
     */
    
    struct ichss_softc {
            device_t         dev;
            int              bm_rid;        /* Bus-mastering control (PM2REG). */
            struct resource *bm_reg;
            int              ctrl_rid;      /* Control/status register. */
            struct resource *ctrl_reg;
            struct cf_setting sets[2];      /* Only two settings. */
    };
    
    /* Supported PCI IDs. */
    #define PCI_VENDOR_INTEL        0x8086
    #define PCI_DEV_82801BA         0x244c /* ICH2M */
    #define PCI_DEV_82801CA         0x248c /* ICH3M */
    #define PCI_DEV_82801DB         0x24cc /* ICH4M */
    #define PCI_DEV_82815_MC        0x1130 /* Unsupported/buggy part */
    
    /* PCI config registers for finding PMBASE and enabling SpeedStep. */
    #define ICHSS_PMBASE_OFFSET     0x40
    #define ICHSS_PMCFG_OFFSET      0xa0
    
    /* Values and masks. */
    #define ICHSS_ENABLE            (1<<3)  /* Enable SpeedStep control. */
    #define ICHSS_IO_REG            0x1     /* Access register via I/O space. */
    #define ICHSS_PMBASE_MASK       0xff80  /* PMBASE address bits. */
    #define ICHSS_CTRL_BIT          0x1     /* 0 is high speed, 1 is low. */
    #define ICHSS_BM_DISABLE        0x1
    
    /* Offsets from PMBASE for various registers. */
    #define ICHSS_BM_OFFSET         0x20
    #define ICHSS_CTRL_OFFSET       0x50
    
    #define ICH_GET_REG(reg)                                \
            (bus_space_read_1(rman_get_bustag((reg)),       \
                rman_get_bushandle((reg)), 0))
    #define ICH_SET_REG(reg, val)                           \
            (bus_space_write_1(rman_get_bustag((reg)),      \
                rman_get_bushandle((reg)), 0, (val)))
    
    static void     ichss_identify(driver_t *driver, device_t parent);
    static int      ichss_probe(device_t dev);
    static int      ichss_attach(device_t dev);
    static int      ichss_detach(device_t dev);
    static int      ichss_settings(device_t dev, struct cf_setting *sets,
                        int *count);
   static int      ichss_set(device_t dev, const struct cf_setting *set);
   static int      ichss_get(device_t dev, struct cf_setting *set);
   static int      ichss_type(device_t dev, int *type);
   
   static device_method_t ichss_methods[] = {
           /* Device interface */
           DEVMETHOD(device_identify,      ichss_identify),
           DEVMETHOD(device_probe,         ichss_probe),
           DEVMETHOD(device_attach,        ichss_attach),
           DEVMETHOD(device_detach,        ichss_detach),
   
           /* cpufreq interface */
           DEVMETHOD(cpufreq_drv_set,      ichss_set),
           DEVMETHOD(cpufreq_drv_get,      ichss_get),
           DEVMETHOD(cpufreq_drv_type,     ichss_type),
           DEVMETHOD(cpufreq_drv_settings, ichss_settings),
           {0, 0}
   };
   static driver_t ichss_driver = {
           "ichss", ichss_methods, sizeof(struct ichss_softc)
   };
   static devclass_t ichss_devclass;
   DRIVER_MODULE(ichss, cpu, ichss_driver, ichss_devclass, 0, 0);
   
   static device_t ich_device;
   
   #if 0
   #define DPRINT(x...)    printf(x)
   #else
   #define DPRINT(x...)
   #endif
   
   static void
   ichss_identify(driver_t *driver, device_t parent)
   {
           device_t child;
           uint32_t pmbase;
   
           if (resource_disabled("ichss", 0))
                   return;
   
           /*
            * It appears that ICH SpeedStep only requires a single CPU to
            * set the value (since the chipset is shared by all CPUs.)
            * Thus, we only add a child to cpu 0.
            */
           if (device_get_unit(parent) != 0)
                   return;
   
           /* Avoid duplicates. */
           if (device_find_child(parent, "ichss", -1))
                   return;
   
           /*
            * ICH2/3/4-M I/O Controller Hub is at bus 0, slot 1F, function 0.
            * E.g. see Section 6.1 "PCI Devices and Functions" and table 6.1 of
            * Intel(r) 82801BA I/O Controller Hub 2 (ICH2) and Intel(r) 82801BAM
            * I/O Controller Hub 2 Mobile (ICH2-M).
            */
           ich_device = pci_find_bsf(0, 0x1f, 0);
           if (ich_device == NULL ||
               pci_get_vendor(ich_device) != PCI_VENDOR_INTEL ||
               (pci_get_device(ich_device) != PCI_DEV_82801BA &&
               pci_get_device(ich_device) != PCI_DEV_82801CA &&
               pci_get_device(ich_device) != PCI_DEV_82801DB))
                   return;
   
           /*
            * Certain systems with ICH2 and an Intel 82815_MC host bridge
            * where the host bridge's revision is < 5 lockup if SpeedStep
            * is used.
            */
           if (pci_get_device(ich_device) == PCI_DEV_82801BA) {
                   device_t hostb;
   
                   hostb = pci_find_bsf(0, 0, 0);
                   if (hostb != NULL &&
                       pci_get_vendor(hostb) == PCI_VENDOR_INTEL &&
                       pci_get_device(hostb) == PCI_DEV_82815_MC &&
                       pci_get_revid(hostb) < 5)
                           return;
           }
   
           /* Find the PMBASE register from our PCI config header. */
           pmbase = pci_read_config(ich_device, ICHSS_PMBASE_OFFSET,
               sizeof(pmbase));
           if ((pmbase & ICHSS_IO_REG) == 0) {
                   printf("ichss: invalid PMBASE memory type\n");
                   return;
           }
           pmbase &= ICHSS_PMBASE_MASK;
           if (pmbase == 0) {
                   printf("ichss: invalid zero PMBASE address\n");
                   return;
           }
           DPRINT("ichss: PMBASE is %#x\n", pmbase);
   
           child = BUS_ADD_CHILD(parent, 20, "ichss", 0);
           if (child == NULL) {
                   device_printf(parent, "add SpeedStep child failed\n");
                   return;
           }
   
           /* Add the bus master arbitration and control registers. */
           bus_set_resource(child, SYS_RES_IOPORT, 0, pmbase + ICHSS_BM_OFFSET,
               1);
           bus_set_resource(child, SYS_RES_IOPORT, 1, pmbase + ICHSS_CTRL_OFFSET,
               1);
   }
   
   static int
   ichss_probe(device_t dev)
   {
           device_t est_dev, perf_dev;
           int error, type;
   
           /*
            * If the ACPI perf driver has attached and is not just offering
            * info, let it manage things.  Also, if Enhanced SpeedStep is
            * available, don't attach.
            */
           perf_dev = device_find_child(device_get_parent(dev), "acpi_perf", -1);
           if (perf_dev && device_is_attached(perf_dev)) {
                   error = CPUFREQ_DRV_TYPE(perf_dev, &type);
                   if (error == 0 && (type & CPUFREQ_FLAG_INFO_ONLY) == 0)
                           return (ENXIO);
           }
           est_dev = device_find_child(device_get_parent(dev), "est", -1);
           if (est_dev && device_is_attached(est_dev))
                   return (ENXIO);
   
           device_set_desc(dev, "SpeedStep ICH");
           return (-1000);
   }
   
   static int
   ichss_attach(device_t dev)
   {
           struct ichss_softc *sc;
           uint16_t ss_en;
   
           sc = device_get_softc(dev);
           sc->dev = dev;
   
           sc->bm_rid = 0;
           sc->bm_reg = bus_alloc_resource_any(dev, SYS_RES_IOPORT, &sc->bm_rid,
               RF_ACTIVE);
           if (sc->bm_reg == NULL) {
                   device_printf(dev, "failed to alloc BM arb register\n");
                   return (ENXIO);
           }
           sc->ctrl_rid = 1;
           sc->ctrl_reg = bus_alloc_resource_any(dev, SYS_RES_IOPORT,
               &sc->ctrl_rid, RF_ACTIVE);
           if (sc->ctrl_reg == NULL) {
                   device_printf(dev, "failed to alloc control register\n");
                   bus_release_resource(dev, SYS_RES_IOPORT, sc->bm_rid,
                       sc->bm_reg);
                   return (ENXIO);
           }
   
           /* Activate SpeedStep control if not already enabled. */
           ss_en = pci_read_config(ich_device, ICHSS_PMCFG_OFFSET, sizeof(ss_en));
           if ((ss_en & ICHSS_ENABLE) == 0) {
                   device_printf(dev, "enabling SpeedStep support\n");
                   pci_write_config(ich_device, ICHSS_PMCFG_OFFSET,
                       ss_en | ICHSS_ENABLE, sizeof(ss_en));
           }
   
           /* Setup some defaults for our exported settings. */
           sc->sets[0].freq = CPUFREQ_VAL_UNKNOWN;
           sc->sets[0].volts = CPUFREQ_VAL_UNKNOWN;
           sc->sets[0].power = CPUFREQ_VAL_UNKNOWN;
           sc->sets[0].lat = 1000;
           sc->sets[0].dev = dev;
           sc->sets[1] = sc->sets[0];
           cpufreq_register(dev);
   
           return (0);
   }
   
   static int
   ichss_detach(device_t dev)
   {
           /* TODO: teardown BM and CTRL registers. */
           return (ENXIO);
   }
   
   static int
   ichss_settings(device_t dev, struct cf_setting *sets, int *count)
   {
           struct ichss_softc *sc;
           struct cf_setting set;
           int first, i;
   
           if (sets == NULL || count == NULL)
                   return (EINVAL);
           if (*count < 2) {
                   *count = 2;
                   return (E2BIG);
           }
           sc = device_get_softc(dev);
   
           /*
            * Estimate frequencies for both levels, temporarily switching to
            * the other one if we haven't calibrated it yet.
            */
           ichss_get(dev, &set);
           for (i = 0; i < 2; i++) {
                   if (sc->sets[i].freq == CPUFREQ_VAL_UNKNOWN) {
                           first = (i == 0) ? 1 : 0;
                           ichss_set(dev, &sc->sets[i]);
                           ichss_set(dev, &sc->sets[first]);
                   }
           }
   
           bcopy(sc->sets, sets, sizeof(sc->sets));
           *count = 2;
   
           return (0);
   }
   
   static int
   ichss_set(device_t dev, const struct cf_setting *set)
   {
           struct ichss_softc *sc;
           uint8_t bmval, new_val, old_val, req_val;
           uint64_t rate;
           register_t regs;
   
           /* Look up appropriate bit value based on frequency. */
           sc = device_get_softc(dev);
           if (CPUFREQ_CMP(set->freq, sc->sets[0].freq))
                   req_val = 0;
           else if (CPUFREQ_CMP(set->freq, sc->sets[1].freq))
                   req_val = ICHSS_CTRL_BIT;
           else
                   return (EINVAL);
           DPRINT("ichss: requested setting %d\n", req_val);
   
           /* Disable interrupts and get the other register contents. */
           regs = intr_disable();
           old_val = ICH_GET_REG(sc->ctrl_reg) & ~ICHSS_CTRL_BIT;
   
           /*
            * Disable bus master arbitration, write the new value to the control
            * register, and then re-enable bus master arbitration.
            */
           bmval = ICH_GET_REG(sc->bm_reg) | ICHSS_BM_DISABLE;
           ICH_SET_REG(sc->bm_reg, bmval);
           ICH_SET_REG(sc->ctrl_reg, old_val | req_val);
           ICH_SET_REG(sc->bm_reg, bmval & ~ICHSS_BM_DISABLE);
   
           /* Get the new value and re-enable interrupts. */
           new_val = ICH_GET_REG(sc->ctrl_reg);
           intr_restore(regs);
   
           /* Check if the desired state was indeed selected. */
           if (req_val != (new_val & ICHSS_CTRL_BIT)) {
               device_printf(sc->dev, "transition to %d failed\n", req_val);
               return (ENXIO);
           }
   
           /* Re-initialize our cycle counter if we don't know this new state. */
           if (sc->sets[req_val].freq == CPUFREQ_VAL_UNKNOWN) {
                   cpu_est_clockrate(0, &rate);
                   sc->sets[req_val].freq = rate / 1000000;
                   DPRINT("ichss: set calibrated new rate of %d\n",
                       sc->sets[req_val].freq);
           }
   
           return (0);
   }
   
   static int
   ichss_get(device_t dev, struct cf_setting *set)
   {
           struct ichss_softc *sc;
           uint64_t rate;
           uint8_t state;
   
           sc = device_get_softc(dev);
           state = ICH_GET_REG(sc->ctrl_reg) & ICHSS_CTRL_BIT;
   
           /* If we haven't changed settings yet, estimate the current value. */
           if (sc->sets[state].freq == CPUFREQ_VAL_UNKNOWN) {
                   cpu_est_clockrate(0, &rate);
                   sc->sets[state].freq = rate / 1000000;
                   DPRINT("ichss: get calibrated new rate of %d\n",
                       sc->sets[state].freq);
           }
           *set = sc->sets[state];
   
           return (0);
   }
   
   static int
   ichss_type(device_t dev, int *type)
   {
   
           if (type == NULL)
                   return (EINVAL);
   
           *type = CPUFREQ_TYPE_ABSOLUTE;
           return (0);
   }

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