diff options
Diffstat (limited to 'drivers/cpufreq/pxa3xx-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/pxa3xx-cpufreq.c | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/drivers/cpufreq/pxa3xx-cpufreq.c b/drivers/cpufreq/pxa3xx-cpufreq.c new file mode 100644 index 00000000000..15d60f857ad --- /dev/null +++ b/drivers/cpufreq/pxa3xx-cpufreq.c @@ -0,0 +1,254 @@ +/* + * Copyright (C) 2008 Marvell International Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/init.h> +#include <linux/cpufreq.h> +#include <linux/slab.h> +#include <linux/io.h> + +#include <mach/generic.h> +#include <mach/pxa3xx-regs.h> + +#define HSS_104M (0) +#define HSS_156M (1) +#define HSS_208M (2) +#define HSS_312M (3) + +#define SMCFS_78M (0) +#define SMCFS_104M (2) +#define SMCFS_208M (5) + +#define SFLFS_104M (0) +#define SFLFS_156M (1) +#define SFLFS_208M (2) +#define SFLFS_312M (3) + +#define XSPCLK_156M (0) +#define XSPCLK_NONE (3) + +#define DMCFS_26M (0) +#define DMCFS_260M (3) + +struct pxa3xx_freq_info { + unsigned int cpufreq_mhz; + unsigned int core_xl : 5; + unsigned int core_xn : 3; + unsigned int hss : 2; + unsigned int dmcfs : 2; + unsigned int smcfs : 3; + unsigned int sflfs : 2; + unsigned int df_clkdiv : 3; + + int vcc_core; /* in mV */ + int vcc_sram; /* in mV */ +}; + +#define OP(cpufreq, _xl, _xn, _hss, _dmc, _smc, _sfl, _dfi, vcore, vsram) \ +{ \ + .cpufreq_mhz = cpufreq, \ + .core_xl = _xl, \ + .core_xn = _xn, \ + .hss = HSS_##_hss##M, \ + .dmcfs = DMCFS_##_dmc##M, \ + .smcfs = SMCFS_##_smc##M, \ + .sflfs = SFLFS_##_sfl##M, \ + .df_clkdiv = _dfi, \ + .vcc_core = vcore, \ + .vcc_sram = vsram, \ +} + +static struct pxa3xx_freq_info pxa300_freqs[] = { + /* CPU XL XN HSS DMEM SMEM SRAM DFI VCC_CORE VCC_SRAM */ + OP(104, 8, 1, 104, 260, 78, 104, 3, 1000, 1100), /* 104MHz */ + OP(208, 16, 1, 104, 260, 104, 156, 2, 1000, 1100), /* 208MHz */ + OP(416, 16, 2, 156, 260, 104, 208, 2, 1100, 1200), /* 416MHz */ + OP(624, 24, 2, 208, 260, 208, 312, 3, 1375, 1400), /* 624MHz */ +}; + +static struct pxa3xx_freq_info pxa320_freqs[] = { + /* CPU XL XN HSS DMEM SMEM SRAM DFI VCC_CORE VCC_SRAM */ + OP(104, 8, 1, 104, 260, 78, 104, 3, 1000, 1100), /* 104MHz */ + OP(208, 16, 1, 104, 260, 104, 156, 2, 1000, 1100), /* 208MHz */ + OP(416, 16, 2, 156, 260, 104, 208, 2, 1100, 1200), /* 416MHz */ + OP(624, 24, 2, 208, 260, 208, 312, 3, 1375, 1400), /* 624MHz */ + OP(806, 31, 2, 208, 260, 208, 312, 3, 1400, 1400), /* 806MHz */ +}; + +static unsigned int pxa3xx_freqs_num; +static struct pxa3xx_freq_info *pxa3xx_freqs; +static struct cpufreq_frequency_table *pxa3xx_freqs_table; + +static int setup_freqs_table(struct cpufreq_policy *policy, + struct pxa3xx_freq_info *freqs, int num) +{ + struct cpufreq_frequency_table *table; + int i; + + table = kzalloc((num + 1) * sizeof(*table), GFP_KERNEL); + if (table == NULL) + return -ENOMEM; + + for (i = 0; i < num; i++) { + table[i].index = i; + table[i].frequency = freqs[i].cpufreq_mhz * 1000; + } + table[num].index = i; + table[num].frequency = CPUFREQ_TABLE_END; + + pxa3xx_freqs = freqs; + pxa3xx_freqs_num = num; + pxa3xx_freqs_table = table; + + return cpufreq_frequency_table_cpuinfo(policy, table); +} + +static void __update_core_freq(struct pxa3xx_freq_info *info) +{ + uint32_t mask = ACCR_XN_MASK | ACCR_XL_MASK; + uint32_t accr = ACCR; + uint32_t xclkcfg; + + accr &= ~(ACCR_XN_MASK | ACCR_XL_MASK | ACCR_XSPCLK_MASK); + accr |= ACCR_XN(info->core_xn) | ACCR_XL(info->core_xl); + + /* No clock until core PLL is re-locked */ + accr |= ACCR_XSPCLK(XSPCLK_NONE); + + xclkcfg = (info->core_xn == 2) ? 0x3 : 0x2; /* turbo bit */ + + ACCR = accr; + __asm__("mcr p14, 0, %0, c6, c0, 0\n" : : "r"(xclkcfg)); + + while ((ACSR & mask) != (accr & mask)) + cpu_relax(); +} + +static void __update_bus_freq(struct pxa3xx_freq_info *info) +{ + uint32_t mask; + uint32_t accr = ACCR; + + mask = ACCR_SMCFS_MASK | ACCR_SFLFS_MASK | ACCR_HSS_MASK | + ACCR_DMCFS_MASK; + + accr &= ~mask; + accr |= ACCR_SMCFS(info->smcfs) | ACCR_SFLFS(info->sflfs) | + ACCR_HSS(info->hss) | ACCR_DMCFS(info->dmcfs); + + ACCR = accr; + + while ((ACSR & mask) != (accr & mask)) + cpu_relax(); +} + +static int pxa3xx_cpufreq_verify(struct cpufreq_policy *policy) +{ + return cpufreq_frequency_table_verify(policy, pxa3xx_freqs_table); +} + +static unsigned int pxa3xx_cpufreq_get(unsigned int cpu) +{ + return pxa3xx_get_clk_frequency_khz(0); +} + +static int pxa3xx_cpufreq_set(struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation) +{ + struct pxa3xx_freq_info *next; + struct cpufreq_freqs freqs; + unsigned long flags; + int idx; + + if (policy->cpu != 0) + return -EINVAL; + + /* Lookup the next frequency */ + if (cpufreq_frequency_table_target(policy, pxa3xx_freqs_table, + target_freq, relation, &idx)) + return -EINVAL; + + next = &pxa3xx_freqs[idx]; + + freqs.old = policy->cur; + freqs.new = next->cpufreq_mhz * 1000; + + pr_debug("CPU frequency from %d MHz to %d MHz%s\n", + freqs.old / 1000, freqs.new / 1000, + (freqs.old == freqs.new) ? " (skipped)" : ""); + + if (freqs.old == target_freq) + return 0; + + cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); + + local_irq_save(flags); + __update_core_freq(next); + __update_bus_freq(next); + local_irq_restore(flags); + + cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); + + return 0; +} + +static int pxa3xx_cpufreq_init(struct cpufreq_policy *policy) +{ + int ret = -EINVAL; + + /* set default policy and cpuinfo */ + policy->cpuinfo.min_freq = 104000; + policy->cpuinfo.max_freq = (cpu_is_pxa320()) ? 806000 : 624000; + policy->cpuinfo.transition_latency = 1000; /* FIXME: 1 ms, assumed */ + policy->max = pxa3xx_get_clk_frequency_khz(0); + policy->cur = policy->min = policy->max; + + if (cpu_is_pxa300() || cpu_is_pxa310()) + ret = setup_freqs_table(policy, ARRAY_AND_SIZE(pxa300_freqs)); + + if (cpu_is_pxa320()) + ret = setup_freqs_table(policy, ARRAY_AND_SIZE(pxa320_freqs)); + + if (ret) { + pr_err("failed to setup frequency table\n"); + return ret; + } + + pr_info("CPUFREQ support for PXA3xx initialized\n"); + return 0; +} + +static struct cpufreq_driver pxa3xx_cpufreq_driver = { + .verify = pxa3xx_cpufreq_verify, + .target = pxa3xx_cpufreq_set, + .init = pxa3xx_cpufreq_init, + .get = pxa3xx_cpufreq_get, + .name = "pxa3xx-cpufreq", +}; + +static int __init cpufreq_init(void) +{ + if (cpu_is_pxa3xx()) + return cpufreq_register_driver(&pxa3xx_cpufreq_driver); + + return 0; +} +module_init(cpufreq_init); + +static void __exit cpufreq_exit(void) +{ + cpufreq_unregister_driver(&pxa3xx_cpufreq_driver); +} +module_exit(cpufreq_exit); + +MODULE_DESCRIPTION("CPU frequency scaling driver for PXA3xx"); +MODULE_LICENSE("GPL"); |