diff options
Diffstat (limited to 'drivers/cpufreq/pmac64-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/pmac64-cpufreq.c | 675 |
1 files changed, 675 insertions, 0 deletions
diff --git a/drivers/cpufreq/pmac64-cpufreq.c b/drivers/cpufreq/pmac64-cpufreq.c new file mode 100644 index 000000000..be623dd7b --- /dev/null +++ b/drivers/cpufreq/pmac64-cpufreq.c @@ -0,0 +1,675 @@ +/* + * Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org> + * and Markus Demleitner <msdemlei@cl.uni-heidelberg.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. + * + * This driver adds basic cpufreq support for SMU & 970FX based G5 Macs, + * that is iMac G5 and latest single CPU desktop. + */ + +#undef DEBUG + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/sched.h> +#include <linux/cpufreq.h> +#include <linux/init.h> +#include <linux/completion.h> +#include <linux/mutex.h> +#include <linux/of_device.h> +#include <asm/prom.h> +#include <asm/machdep.h> +#include <asm/irq.h> +#include <asm/sections.h> +#include <asm/cputable.h> +#include <asm/time.h> +#include <asm/smu.h> +#include <asm/pmac_pfunc.h> + +#define DBG(fmt...) pr_debug(fmt) + +/* see 970FX user manual */ + +#define SCOM_PCR 0x0aa001 /* PCR scom addr */ + +#define PCR_HILO_SELECT 0x80000000U /* 1 = PCR, 0 = PCRH */ +#define PCR_SPEED_FULL 0x00000000U /* 1:1 speed value */ +#define PCR_SPEED_HALF 0x00020000U /* 1:2 speed value */ +#define PCR_SPEED_QUARTER 0x00040000U /* 1:4 speed value */ +#define PCR_SPEED_MASK 0x000e0000U /* speed mask */ +#define PCR_SPEED_SHIFT 17 +#define PCR_FREQ_REQ_VALID 0x00010000U /* freq request valid */ +#define PCR_VOLT_REQ_VALID 0x00008000U /* volt request valid */ +#define PCR_TARGET_TIME_MASK 0x00006000U /* target time */ +#define PCR_STATLAT_MASK 0x00001f00U /* STATLAT value */ +#define PCR_SNOOPLAT_MASK 0x000000f0U /* SNOOPLAT value */ +#define PCR_SNOOPACC_MASK 0x0000000fU /* SNOOPACC value */ + +#define SCOM_PSR 0x408001 /* PSR scom addr */ +/* warning: PSR is a 64 bits register */ +#define PSR_CMD_RECEIVED 0x2000000000000000U /* command received */ +#define PSR_CMD_COMPLETED 0x1000000000000000U /* command completed */ +#define PSR_CUR_SPEED_MASK 0x0300000000000000U /* current speed */ +#define PSR_CUR_SPEED_SHIFT (56) + +/* + * The G5 only supports two frequencies (Quarter speed is not supported) + */ +#define CPUFREQ_HIGH 0 +#define CPUFREQ_LOW 1 + +static struct cpufreq_frequency_table g5_cpu_freqs[] = { + {0, CPUFREQ_HIGH, 0}, + {0, CPUFREQ_LOW, 0}, + {0, 0, CPUFREQ_TABLE_END}, +}; + +/* Power mode data is an array of the 32 bits PCR values to use for + * the various frequencies, retrieved from the device-tree + */ +static int g5_pmode_cur; + +static void (*g5_switch_volt)(int speed_mode); +static int (*g5_switch_freq)(int speed_mode); +static int (*g5_query_freq)(void); + +static unsigned long transition_latency; + +#ifdef CONFIG_PMAC_SMU + +static const u32 *g5_pmode_data; +static int g5_pmode_max; + +static struct smu_sdbp_fvt *g5_fvt_table; /* table of op. points */ +static int g5_fvt_count; /* number of op. points */ +static int g5_fvt_cur; /* current op. point */ + +/* + * SMU based voltage switching for Neo2 platforms + */ + +static void g5_smu_switch_volt(int speed_mode) +{ + struct smu_simple_cmd cmd; + + DECLARE_COMPLETION_ONSTACK(comp); + smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, smu_done_complete, + &comp, 'V', 'S', 'L', 'E', 'W', + 0xff, g5_fvt_cur+1, speed_mode); + wait_for_completion(&comp); +} + +/* + * Platform function based voltage/vdnap switching for Neo2 + */ + +static struct pmf_function *pfunc_set_vdnap0; +static struct pmf_function *pfunc_vdnap0_complete; + +static void g5_vdnap_switch_volt(int speed_mode) +{ + struct pmf_args args; + u32 slew, done = 0; + unsigned long timeout; + + slew = (speed_mode == CPUFREQ_LOW) ? 1 : 0; + args.count = 1; + args.u[0].p = &slew; + + pmf_call_one(pfunc_set_vdnap0, &args); + + /* It's an irq GPIO so we should be able to just block here, + * I'll do that later after I've properly tested the IRQ code for + * platform functions + */ + timeout = jiffies + HZ/10; + while(!time_after(jiffies, timeout)) { + args.count = 1; + args.u[0].p = &done; + pmf_call_one(pfunc_vdnap0_complete, &args); + if (done) + break; + usleep_range(1000, 1000); + } + if (done == 0) + pr_warn("Timeout in clock slewing !\n"); +} + + +/* + * SCOM based frequency switching for 970FX rev3 + */ +static int g5_scom_switch_freq(int speed_mode) +{ + unsigned long flags; + int to; + + /* If frequency is going up, first ramp up the voltage */ + if (speed_mode < g5_pmode_cur) + g5_switch_volt(speed_mode); + + local_irq_save(flags); + + /* Clear PCR high */ + scom970_write(SCOM_PCR, 0); + /* Clear PCR low */ + scom970_write(SCOM_PCR, PCR_HILO_SELECT | 0); + /* Set PCR low */ + scom970_write(SCOM_PCR, PCR_HILO_SELECT | + g5_pmode_data[speed_mode]); + + /* Wait for completion */ + for (to = 0; to < 10; to++) { + unsigned long psr = scom970_read(SCOM_PSR); + + if ((psr & PSR_CMD_RECEIVED) == 0 && + (((psr >> PSR_CUR_SPEED_SHIFT) ^ + (g5_pmode_data[speed_mode] >> PCR_SPEED_SHIFT)) & 0x3) + == 0) + break; + if (psr & PSR_CMD_COMPLETED) + break; + udelay(100); + } + + local_irq_restore(flags); + + /* If frequency is going down, last ramp the voltage */ + if (speed_mode > g5_pmode_cur) + g5_switch_volt(speed_mode); + + g5_pmode_cur = speed_mode; + ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul; + + return 0; +} + +static int g5_scom_query_freq(void) +{ + unsigned long psr = scom970_read(SCOM_PSR); + int i; + + for (i = 0; i <= g5_pmode_max; i++) + if ((((psr >> PSR_CUR_SPEED_SHIFT) ^ + (g5_pmode_data[i] >> PCR_SPEED_SHIFT)) & 0x3) == 0) + break; + return i; +} + +/* + * Fake voltage switching for platforms with missing support + */ + +static void g5_dummy_switch_volt(int speed_mode) +{ +} + +#endif /* CONFIG_PMAC_SMU */ + +/* + * Platform function based voltage switching for PowerMac7,2 & 7,3 + */ + +static struct pmf_function *pfunc_cpu0_volt_high; +static struct pmf_function *pfunc_cpu0_volt_low; +static struct pmf_function *pfunc_cpu1_volt_high; +static struct pmf_function *pfunc_cpu1_volt_low; + +static void g5_pfunc_switch_volt(int speed_mode) +{ + if (speed_mode == CPUFREQ_HIGH) { + if (pfunc_cpu0_volt_high) + pmf_call_one(pfunc_cpu0_volt_high, NULL); + if (pfunc_cpu1_volt_high) + pmf_call_one(pfunc_cpu1_volt_high, NULL); + } else { + if (pfunc_cpu0_volt_low) + pmf_call_one(pfunc_cpu0_volt_low, NULL); + if (pfunc_cpu1_volt_low) + pmf_call_one(pfunc_cpu1_volt_low, NULL); + } + usleep_range(10000, 10000); /* should be faster , to fix */ +} + +/* + * Platform function based frequency switching for PowerMac7,2 & 7,3 + */ + +static struct pmf_function *pfunc_cpu_setfreq_high; +static struct pmf_function *pfunc_cpu_setfreq_low; +static struct pmf_function *pfunc_cpu_getfreq; +static struct pmf_function *pfunc_slewing_done; + +static int g5_pfunc_switch_freq(int speed_mode) +{ + struct pmf_args args; + u32 done = 0; + unsigned long timeout; + int rc; + + DBG("g5_pfunc_switch_freq(%d)\n", speed_mode); + + /* If frequency is going up, first ramp up the voltage */ + if (speed_mode < g5_pmode_cur) + g5_switch_volt(speed_mode); + + /* Do it */ + if (speed_mode == CPUFREQ_HIGH) + rc = pmf_call_one(pfunc_cpu_setfreq_high, NULL); + else + rc = pmf_call_one(pfunc_cpu_setfreq_low, NULL); + + if (rc) + pr_warn("pfunc switch error %d\n", rc); + + /* It's an irq GPIO so we should be able to just block here, + * I'll do that later after I've properly tested the IRQ code for + * platform functions + */ + timeout = jiffies + HZ/10; + while(!time_after(jiffies, timeout)) { + args.count = 1; + args.u[0].p = &done; + pmf_call_one(pfunc_slewing_done, &args); + if (done) + break; + usleep_range(500, 500); + } + if (done == 0) + pr_warn("Timeout in clock slewing !\n"); + + /* If frequency is going down, last ramp the voltage */ + if (speed_mode > g5_pmode_cur) + g5_switch_volt(speed_mode); + + g5_pmode_cur = speed_mode; + ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul; + + return 0; +} + +static int g5_pfunc_query_freq(void) +{ + struct pmf_args args; + u32 val = 0; + + args.count = 1; + args.u[0].p = &val; + pmf_call_one(pfunc_cpu_getfreq, &args); + return val ? CPUFREQ_HIGH : CPUFREQ_LOW; +} + + +/* + * Common interface to the cpufreq core + */ + +static int g5_cpufreq_target(struct cpufreq_policy *policy, unsigned int index) +{ + return g5_switch_freq(index); +} + +static unsigned int g5_cpufreq_get_speed(unsigned int cpu) +{ + return g5_cpu_freqs[g5_pmode_cur].frequency; +} + +static int g5_cpufreq_cpu_init(struct cpufreq_policy *policy) +{ + return cpufreq_generic_init(policy, g5_cpu_freqs, transition_latency); +} + +static struct cpufreq_driver g5_cpufreq_driver = { + .name = "powermac", + .flags = CPUFREQ_CONST_LOOPS, + .init = g5_cpufreq_cpu_init, + .verify = cpufreq_generic_frequency_table_verify, + .target_index = g5_cpufreq_target, + .get = g5_cpufreq_get_speed, + .attr = cpufreq_generic_attr, +}; + + +#ifdef CONFIG_PMAC_SMU + +static int __init g5_neo2_cpufreq_init(struct device_node *cpunode) +{ + unsigned int psize, ssize; + unsigned long max_freq; + char *freq_method, *volt_method; + const u32 *valp; + u32 pvr_hi; + int use_volts_vdnap = 0; + int use_volts_smu = 0; + int rc = -ENODEV; + + /* Check supported platforms */ + if (of_machine_is_compatible("PowerMac8,1") || + of_machine_is_compatible("PowerMac8,2") || + of_machine_is_compatible("PowerMac9,1") || + of_machine_is_compatible("PowerMac12,1")) + use_volts_smu = 1; + else if (of_machine_is_compatible("PowerMac11,2")) + use_volts_vdnap = 1; + else + return -ENODEV; + + /* Check 970FX for now */ + valp = of_get_property(cpunode, "cpu-version", NULL); + if (!valp) { + DBG("No cpu-version property !\n"); + goto bail_noprops; + } + pvr_hi = (*valp) >> 16; + if (pvr_hi != 0x3c && pvr_hi != 0x44) { + pr_err("Unsupported CPU version\n"); + goto bail_noprops; + } + + /* Look for the powertune data in the device-tree */ + g5_pmode_data = of_get_property(cpunode, "power-mode-data",&psize); + if (!g5_pmode_data) { + DBG("No power-mode-data !\n"); + goto bail_noprops; + } + g5_pmode_max = psize / sizeof(u32) - 1; + + if (use_volts_smu) { + const struct smu_sdbp_header *shdr; + + /* Look for the FVT table */ + shdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL); + if (!shdr) + goto bail_noprops; + g5_fvt_table = (struct smu_sdbp_fvt *)&shdr[1]; + ssize = (shdr->len * sizeof(u32)) - sizeof(*shdr); + g5_fvt_count = ssize / sizeof(*g5_fvt_table); + g5_fvt_cur = 0; + + /* Sanity checking */ + if (g5_fvt_count < 1 || g5_pmode_max < 1) + goto bail_noprops; + + g5_switch_volt = g5_smu_switch_volt; + volt_method = "SMU"; + } else if (use_volts_vdnap) { + struct device_node *root; + + root = of_find_node_by_path("/"); + if (root == NULL) { + pr_err("Can't find root of device tree\n"); + goto bail_noprops; + } + pfunc_set_vdnap0 = pmf_find_function(root, "set-vdnap0"); + pfunc_vdnap0_complete = + pmf_find_function(root, "slewing-done"); + if (pfunc_set_vdnap0 == NULL || + pfunc_vdnap0_complete == NULL) { + pr_err("Can't find required platform function\n"); + goto bail_noprops; + } + + g5_switch_volt = g5_vdnap_switch_volt; + volt_method = "GPIO"; + } else { + g5_switch_volt = g5_dummy_switch_volt; + volt_method = "none"; + } + + /* + * From what I see, clock-frequency is always the maximal frequency. + * The current driver can not slew sysclk yet, so we really only deal + * with powertune steps for now. We also only implement full freq and + * half freq in this version. So far, I haven't yet seen a machine + * supporting anything else. + */ + valp = of_get_property(cpunode, "clock-frequency", NULL); + if (!valp) + return -ENODEV; + max_freq = (*valp)/1000; + g5_cpu_freqs[0].frequency = max_freq; + g5_cpu_freqs[1].frequency = max_freq/2; + + /* Set callbacks */ + transition_latency = 12000; + g5_switch_freq = g5_scom_switch_freq; + g5_query_freq = g5_scom_query_freq; + freq_method = "SCOM"; + + /* Force apply current frequency to make sure everything is in + * sync (voltage is right for example). Firmware may leave us with + * a strange setting ... + */ + g5_switch_volt(CPUFREQ_HIGH); + msleep(10); + g5_pmode_cur = -1; + g5_switch_freq(g5_query_freq()); + + pr_info("Registering G5 CPU frequency driver\n"); + pr_info("Frequency method: %s, Voltage method: %s\n", + freq_method, volt_method); + pr_info("Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n", + g5_cpu_freqs[1].frequency/1000, + g5_cpu_freqs[0].frequency/1000, + g5_cpu_freqs[g5_pmode_cur].frequency/1000); + + rc = cpufreq_register_driver(&g5_cpufreq_driver); + + /* We keep the CPU node on hold... hopefully, Apple G5 don't have + * hotplug CPU with a dynamic device-tree ... + */ + return rc; + + bail_noprops: + of_node_put(cpunode); + + return rc; +} + +#endif /* CONFIG_PMAC_SMU */ + + +static int __init g5_pm72_cpufreq_init(struct device_node *cpunode) +{ + struct device_node *cpuid = NULL, *hwclock = NULL; + const u8 *eeprom = NULL; + const u32 *valp; + u64 max_freq, min_freq, ih, il; + int has_volt = 1, rc = 0; + + DBG("cpufreq: Initializing for PowerMac7,2, PowerMac7,3 and" + " RackMac3,1...\n"); + + /* Lookup the cpuid eeprom node */ + cpuid = of_find_node_by_path("/u3@0,f8000000/i2c@f8001000/cpuid@a0"); + if (cpuid != NULL) + eeprom = of_get_property(cpuid, "cpuid", NULL); + if (eeprom == NULL) { + pr_err("Can't find cpuid EEPROM !\n"); + rc = -ENODEV; + goto bail; + } + + /* Lookup the i2c hwclock */ + for_each_node_by_name(hwclock, "i2c-hwclock") { + const char *loc = of_get_property(hwclock, + "hwctrl-location", NULL); + if (loc == NULL) + continue; + if (strcmp(loc, "CPU CLOCK")) + continue; + if (!of_get_property(hwclock, "platform-get-frequency", NULL)) + continue; + break; + } + if (hwclock == NULL) { + pr_err("Can't find i2c clock chip !\n"); + rc = -ENODEV; + goto bail; + } + + DBG("cpufreq: i2c clock chip found: %pOF\n", hwclock); + + /* Now get all the platform functions */ + pfunc_cpu_getfreq = + pmf_find_function(hwclock, "get-frequency"); + pfunc_cpu_setfreq_high = + pmf_find_function(hwclock, "set-frequency-high"); + pfunc_cpu_setfreq_low = + pmf_find_function(hwclock, "set-frequency-low"); + pfunc_slewing_done = + pmf_find_function(hwclock, "slewing-done"); + pfunc_cpu0_volt_high = + pmf_find_function(hwclock, "set-voltage-high-0"); + pfunc_cpu0_volt_low = + pmf_find_function(hwclock, "set-voltage-low-0"); + pfunc_cpu1_volt_high = + pmf_find_function(hwclock, "set-voltage-high-1"); + pfunc_cpu1_volt_low = + pmf_find_function(hwclock, "set-voltage-low-1"); + + /* Check we have minimum requirements */ + if (pfunc_cpu_getfreq == NULL || pfunc_cpu_setfreq_high == NULL || + pfunc_cpu_setfreq_low == NULL || pfunc_slewing_done == NULL) { + pr_err("Can't find platform functions !\n"); + rc = -ENODEV; + goto bail; + } + + /* Check that we have complete sets */ + if (pfunc_cpu0_volt_high == NULL || pfunc_cpu0_volt_low == NULL) { + pmf_put_function(pfunc_cpu0_volt_high); + pmf_put_function(pfunc_cpu0_volt_low); + pfunc_cpu0_volt_high = pfunc_cpu0_volt_low = NULL; + has_volt = 0; + } + if (!has_volt || + pfunc_cpu1_volt_high == NULL || pfunc_cpu1_volt_low == NULL) { + pmf_put_function(pfunc_cpu1_volt_high); + pmf_put_function(pfunc_cpu1_volt_low); + pfunc_cpu1_volt_high = pfunc_cpu1_volt_low = NULL; + } + + /* Note: The device tree also contains a "platform-set-values" + * function for which I haven't quite figured out the usage. It + * might have to be called on init and/or wakeup, I'm not too sure + * but things seem to work fine without it so far ... + */ + + /* Get max frequency from device-tree */ + valp = of_get_property(cpunode, "clock-frequency", NULL); + if (!valp) { + pr_err("Can't find CPU frequency !\n"); + rc = -ENODEV; + goto bail; + } + + max_freq = (*valp)/1000; + + /* Now calculate reduced frequency by using the cpuid input freq + * ratio. This requires 64 bits math unless we are willing to lose + * some precision + */ + ih = *((u32 *)(eeprom + 0x10)); + il = *((u32 *)(eeprom + 0x20)); + + /* Check for machines with no useful settings */ + if (il == ih) { + pr_warn("No low frequency mode available on this model !\n"); + rc = -ENODEV; + goto bail; + } + + min_freq = 0; + if (ih != 0 && il != 0) + min_freq = (max_freq * il) / ih; + + /* Sanity check */ + if (min_freq >= max_freq || min_freq < 1000) { + pr_err("Can't calculate low frequency !\n"); + rc = -ENXIO; + goto bail; + } + g5_cpu_freqs[0].frequency = max_freq; + g5_cpu_freqs[1].frequency = min_freq; + + /* Based on a measurement on Xserve G5, rounded up. */ + transition_latency = 10 * NSEC_PER_MSEC; + + /* Set callbacks */ + g5_switch_volt = g5_pfunc_switch_volt; + g5_switch_freq = g5_pfunc_switch_freq; + g5_query_freq = g5_pfunc_query_freq; + + /* Force apply current frequency to make sure everything is in + * sync (voltage is right for example). Firmware may leave us with + * a strange setting ... + */ + g5_switch_volt(CPUFREQ_HIGH); + msleep(10); + g5_pmode_cur = -1; + g5_switch_freq(g5_query_freq()); + + pr_info("Registering G5 CPU frequency driver\n"); + pr_info("Frequency method: i2c/pfunc, Voltage method: %s\n", + has_volt ? "i2c/pfunc" : "none"); + pr_info("Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n", + g5_cpu_freqs[1].frequency/1000, + g5_cpu_freqs[0].frequency/1000, + g5_cpu_freqs[g5_pmode_cur].frequency/1000); + + rc = cpufreq_register_driver(&g5_cpufreq_driver); + bail: + if (rc != 0) { + pmf_put_function(pfunc_cpu_getfreq); + pmf_put_function(pfunc_cpu_setfreq_high); + pmf_put_function(pfunc_cpu_setfreq_low); + pmf_put_function(pfunc_slewing_done); + pmf_put_function(pfunc_cpu0_volt_high); + pmf_put_function(pfunc_cpu0_volt_low); + pmf_put_function(pfunc_cpu1_volt_high); + pmf_put_function(pfunc_cpu1_volt_low); + } + of_node_put(hwclock); + of_node_put(cpuid); + of_node_put(cpunode); + + return rc; +} + +static int __init g5_cpufreq_init(void) +{ + struct device_node *cpunode; + int rc = 0; + + /* Get first CPU node */ + cpunode = of_cpu_device_node_get(0); + if (cpunode == NULL) { + pr_err("Can't find any CPU node\n"); + return -ENODEV; + } + + if (of_machine_is_compatible("PowerMac7,2") || + of_machine_is_compatible("PowerMac7,3") || + of_machine_is_compatible("RackMac3,1")) + rc = g5_pm72_cpufreq_init(cpunode); +#ifdef CONFIG_PMAC_SMU + else + rc = g5_neo2_cpufreq_init(cpunode); +#endif /* CONFIG_PMAC_SMU */ + + return rc; +} + +module_init(g5_cpufreq_init); + + +MODULE_LICENSE("GPL"); |