+++ /dev/null
-/*
- * (C) 2004-2006 Sebastian Witt <se.witt@gmx.net>
- *
- * Licensed under the terms of the GNU GPL License version 2.
- * Based upon reverse engineered information
- *
- * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/init.h>
-#include <linux/cpufreq.h>
-#include <linux/pci.h>
-#include <linux/delay.h>
-
-#define NFORCE2_XTAL 25
-#define NFORCE2_BOOTFSB 0x48
-#define NFORCE2_PLLENABLE 0xa8
-#define NFORCE2_PLLREG 0xa4
-#define NFORCE2_PLLADR 0xa0
-#define NFORCE2_PLL(mul, div) (0x100000 | (mul << 8) | div)
-
-#define NFORCE2_MIN_FSB 50
-#define NFORCE2_SAFE_DISTANCE 50
-
-/* Delay in ms between FSB changes */
-//#define NFORCE2_DELAY 10
-
-/* nforce2_chipset:
- * FSB is changed using the chipset
- */
-static struct pci_dev *nforce2_chipset_dev;
-
-/* fid:
- * multiplier * 10
- */
-static int fid = 0;
-
-/* min_fsb, max_fsb:
- * minimum and maximum FSB (= FSB at boot time)
- */
-static int min_fsb = 0;
-static int max_fsb = 0;
-
-MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>");
-MODULE_DESCRIPTION("nForce2 FSB changing cpufreq driver");
-MODULE_LICENSE("GPL");
-
-module_param(fid, int, 0444);
-module_param(min_fsb, int, 0444);
-
-MODULE_PARM_DESC(fid, "CPU multiplier to use (11.5 = 115)");
-MODULE_PARM_DESC(min_fsb,
- "Minimum FSB to use, if not defined: current FSB - 50");
-
-#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "cpufreq-nforce2", msg)
-
-/**
- * nforce2_calc_fsb - calculate FSB
- * @pll: PLL value
- *
- * Calculates FSB from PLL value
- */
-static int nforce2_calc_fsb(int pll)
-{
- unsigned char mul, div;
-
- mul = (pll >> 8) & 0xff;
- div = pll & 0xff;
-
- if (div > 0)
- return NFORCE2_XTAL * mul / div;
-
- return 0;
-}
-
-/**
- * nforce2_calc_pll - calculate PLL value
- * @fsb: FSB
- *
- * Calculate PLL value for given FSB
- */
-static int nforce2_calc_pll(unsigned int fsb)
-{
- unsigned char xmul, xdiv;
- unsigned char mul = 0, div = 0;
- int tried = 0;
-
- /* Try to calculate multiplier and divider up to 4 times */
- while (((mul == 0) || (div == 0)) && (tried <= 3)) {
- for (xdiv = 2; xdiv <= 0x80; xdiv++)
- for (xmul = 1; xmul <= 0xfe; xmul++)
- if (nforce2_calc_fsb(NFORCE2_PLL(xmul, xdiv)) ==
- fsb + tried) {
- mul = xmul;
- div = xdiv;
- }
- tried++;
- }
-
- if ((mul == 0) || (div == 0))
- return -1;
-
- return NFORCE2_PLL(mul, div);
-}
-
-/**
- * nforce2_write_pll - write PLL value to chipset
- * @pll: PLL value
- *
- * Writes new FSB PLL value to chipset
- */
-static void nforce2_write_pll(int pll)
-{
- int temp;
-
- /* Set the pll addr. to 0x00 */
- pci_write_config_dword(nforce2_chipset_dev, NFORCE2_PLLADR, 0);
-
- /* Now write the value in all 64 registers */
- for (temp = 0; temp <= 0x3f; temp++)
- pci_write_config_dword(nforce2_chipset_dev, NFORCE2_PLLREG, pll);
-
- return;
-}
-
-/**
- * nforce2_fsb_read - Read FSB
- *
- * Read FSB from chipset
- * If bootfsb != 0, return FSB at boot-time
- */
-static unsigned int nforce2_fsb_read(int bootfsb)
-{
- struct pci_dev *nforce2_sub5;
- u32 fsb, temp = 0;
-
- /* Get chipset boot FSB from subdevice 5 (FSB at boot-time) */
- nforce2_sub5 = pci_get_subsys(PCI_VENDOR_ID_NVIDIA,
- 0x01EF,PCI_ANY_ID,PCI_ANY_ID,NULL);
- if (!nforce2_sub5)
- return 0;
-
- pci_read_config_dword(nforce2_sub5, NFORCE2_BOOTFSB, &fsb);
- fsb /= 1000000;
-
- /* Check if PLL register is already set */
- pci_read_config_byte(nforce2_chipset_dev,NFORCE2_PLLENABLE, (u8 *)&temp);
-
- if(bootfsb || !temp)
- return fsb;
-
- /* Use PLL register FSB value */
- pci_read_config_dword(nforce2_chipset_dev,NFORCE2_PLLREG, &temp);
- fsb = nforce2_calc_fsb(temp);
-
- return fsb;
-}
-
-/**
- * nforce2_set_fsb - set new FSB
- * @fsb: New FSB
- *
- * Sets new FSB
- */
-static int nforce2_set_fsb(unsigned int fsb)
-{
- u32 temp = 0;
- unsigned int tfsb;
- int diff;
- int pll = 0;
-
- if ((fsb > max_fsb) || (fsb < NFORCE2_MIN_FSB)) {
- printk(KERN_ERR "cpufreq: FSB %d is out of range!\n", fsb);
- return -EINVAL;
- }
-
- tfsb = nforce2_fsb_read(0);
- if (!tfsb) {
- printk(KERN_ERR "cpufreq: Error while reading the FSB\n");
- return -EINVAL;
- }
-
- /* First write? Then set actual value */
- pci_read_config_byte(nforce2_chipset_dev,NFORCE2_PLLENABLE, (u8 *)&temp);
- if (!temp) {
- pll = nforce2_calc_pll(tfsb);
-
- if (pll < 0)
- return -EINVAL;
-
- nforce2_write_pll(pll);
- }
-
- /* Enable write access */
- temp = 0x01;
- pci_write_config_byte(nforce2_chipset_dev, NFORCE2_PLLENABLE, (u8)temp);
-
- diff = tfsb - fsb;
-
- if (!diff)
- return 0;
-
- while ((tfsb != fsb) && (tfsb <= max_fsb) && (tfsb >= min_fsb)) {
- if (diff < 0)
- tfsb++;
- else
- tfsb--;
-
- /* Calculate the PLL reg. value */
- if ((pll = nforce2_calc_pll(tfsb)) == -1)
- return -EINVAL;
-
- nforce2_write_pll(pll);
-#ifdef NFORCE2_DELAY
- mdelay(NFORCE2_DELAY);
-#endif
- }
-
- temp = 0x40;
- pci_write_config_byte(nforce2_chipset_dev, NFORCE2_PLLADR, (u8)temp);
-
- return 0;
-}
-
-/**
- * nforce2_get - get the CPU frequency
- * @cpu: CPU number
- *
- * Returns the CPU frequency
- */
-static unsigned int nforce2_get(unsigned int cpu)
-{
- if (cpu)
- return 0;
- return nforce2_fsb_read(0) * fid * 100;
-}
-
-/**
- * nforce2_target - set a new CPUFreq policy
- * @policy: new policy
- * @target_freq: the target frequency
- * @relation: how that frequency relates to achieved frequency (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H)
- *
- * Sets a new CPUFreq policy.
- */
-static int nforce2_target(struct cpufreq_policy *policy,
- unsigned int target_freq, unsigned int relation)
-{
-// unsigned long flags;
- struct cpufreq_freqs freqs;
- unsigned int target_fsb;
-
- if ((target_freq > policy->max) || (target_freq < policy->min))
- return -EINVAL;
-
- target_fsb = target_freq / (fid * 100);
-
- freqs.old = nforce2_get(policy->cpu);
- freqs.new = target_fsb * fid * 100;
- freqs.cpu = 0; /* Only one CPU on nForce2 plattforms */
-
- if (freqs.old == freqs.new)
- return 0;
-
- dprintk("Old CPU frequency %d kHz, new %d kHz\n",
- freqs.old, freqs.new);
-
- cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
-
- /* Disable IRQs */
- //local_irq_save(flags);
-
- if (nforce2_set_fsb(target_fsb) < 0)
- printk(KERN_ERR "cpufreq: Changing FSB to %d failed\n",
- target_fsb);
- else
- dprintk("Changed FSB successfully to %d\n",
- target_fsb);
-
- /* Enable IRQs */
- //local_irq_restore(flags);
-
- cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
-
- return 0;
-}
-
-/**
- * nforce2_verify - verifies a new CPUFreq policy
- * @policy: new policy
- */
-static int nforce2_verify(struct cpufreq_policy *policy)
-{
- unsigned int fsb_pol_max;
-
- fsb_pol_max = policy->max / (fid * 100);
-
- if (policy->min < (fsb_pol_max * fid * 100))
- policy->max = (fsb_pol_max + 1) * fid * 100;
-
- cpufreq_verify_within_limits(policy,
- policy->cpuinfo.min_freq,
- policy->cpuinfo.max_freq);
- return 0;
-}
-
-static int nforce2_cpu_init(struct cpufreq_policy *policy)
-{
- unsigned int fsb;
- unsigned int rfid;
-
- /* capability check */
- if (policy->cpu != 0)
- return -ENODEV;
-
- /* Get current FSB */
- fsb = nforce2_fsb_read(0);
-
- if (!fsb)
- return -EIO;
-
- /* FIX: Get FID from CPU */
- if (!fid) {
- if (!cpu_khz) {
- printk(KERN_WARNING
- "cpufreq: cpu_khz not set, can't calculate multiplier!\n");
- return -ENODEV;
- }
-
- fid = cpu_khz / (fsb * 100);
- rfid = fid % 5;
-
- if (rfid) {
- if (rfid > 2)
- fid += 5 - rfid;
- else
- fid -= rfid;
- }
- }
-
- printk(KERN_INFO "cpufreq: FSB currently at %i MHz, FID %d.%d\n", fsb,
- fid / 10, fid % 10);
-
- /* Set maximum FSB to FSB at boot time */
- max_fsb = nforce2_fsb_read(1);
-
- if(!max_fsb)
- return -EIO;
-
- if (!min_fsb)
- min_fsb = max_fsb - NFORCE2_SAFE_DISTANCE;
-
- if (min_fsb < NFORCE2_MIN_FSB)
- min_fsb = NFORCE2_MIN_FSB;
-
- /* cpuinfo and default policy values */
- policy->cpuinfo.min_freq = min_fsb * fid * 100;
- policy->cpuinfo.max_freq = max_fsb * fid * 100;
- policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
- policy->cur = nforce2_get(policy->cpu);
- policy->min = policy->cpuinfo.min_freq;
- policy->max = policy->cpuinfo.max_freq;
- policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
-
- return 0;
-}
-
-static int nforce2_cpu_exit(struct cpufreq_policy *policy)
-{
- return 0;
-}
-
-static struct cpufreq_driver nforce2_driver = {
- .name = "nforce2",
- .verify = nforce2_verify,
- .target = nforce2_target,
- .get = nforce2_get,
- .init = nforce2_cpu_init,
- .exit = nforce2_cpu_exit,
- .owner = THIS_MODULE,
-};
-
-/**
- * nforce2_detect_chipset - detect the Southbridge which contains FSB PLL logic
- *
- * Detects nForce2 A2 and C1 stepping
- *
- */
-static unsigned int nforce2_detect_chipset(void)
-{
- nforce2_chipset_dev = pci_get_subsys(PCI_VENDOR_ID_NVIDIA,
- PCI_DEVICE_ID_NVIDIA_NFORCE2,
- PCI_ANY_ID, PCI_ANY_ID, NULL);
-
- if (nforce2_chipset_dev == NULL)
- return -ENODEV;
-
- printk(KERN_INFO "cpufreq: Detected nForce2 chipset revision %X\n",
- nforce2_chipset_dev->revision);
- printk(KERN_INFO
- "cpufreq: FSB changing is maybe unstable and can lead to crashes and data loss.\n");
-
- return 0;
-}
-
-/**
- * nforce2_init - initializes the nForce2 CPUFreq driver
- *
- * Initializes the nForce2 FSB support. Returns -ENODEV on unsupported
- * devices, -EINVAL on problems during initiatization, and zero on
- * success.
- */
-static int __init nforce2_init(void)
-{
- /* TODO: do we need to detect the processor? */
-
- /* detect chipset */
- if (nforce2_detect_chipset()) {
- printk(KERN_ERR "cpufreq: No nForce2 chipset.\n");
- return -ENODEV;
- }
-
- return cpufreq_register_driver(&nforce2_driver);
-}
-
-/**
- * nforce2_exit - unregisters cpufreq module
- *
- * Unregisters nForce2 FSB change support.
- */
-static void __exit nforce2_exit(void)
-{
- cpufreq_unregister_driver(&nforce2_driver);
-}
-
-module_init(nforce2_init);
-module_exit(nforce2_exit);
-
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