diff options
Diffstat (limited to 'drivers/cpufreq/pxa2xx-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/pxa2xx-cpufreq.c | 321 |
1 files changed, 321 insertions, 0 deletions
diff --git a/drivers/cpufreq/pxa2xx-cpufreq.c b/drivers/cpufreq/pxa2xx-cpufreq.c new file mode 100644 index 000000000..ed1ae061a --- /dev/null +++ b/drivers/cpufreq/pxa2xx-cpufreq.c @@ -0,0 +1,321 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2002,2003 Intrinsyc Software + * + * History: + * 31-Jul-2002 : Initial version [FB] + * 29-Jan-2003 : added PXA255 support [FB] + * 20-Apr-2003 : ported to v2.5 (Dustin McIntire, Sensoria Corp.) + * + * Note: + * This driver may change the memory bus clock rate, but will not do any + * platform specific access timing changes... for example if you have flash + * memory connected to CS0, you will need to register a platform specific + * notifier which will adjust the memory access strobes to maintain a + * minimum strobe width. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/init.h> +#include <linux/cpufreq.h> +#include <linux/err.h> +#include <linux/regulator/consumer.h> +#include <linux/soc/pxa/cpu.h> +#include <linux/io.h> + +#ifdef DEBUG +static unsigned int freq_debug; +module_param(freq_debug, uint, 0); +MODULE_PARM_DESC(freq_debug, "Set the debug messages to on=1/off=0"); +#else +#define freq_debug 0 +#endif + +static struct regulator *vcc_core; + +static unsigned int pxa27x_maxfreq; +module_param(pxa27x_maxfreq, uint, 0); +MODULE_PARM_DESC(pxa27x_maxfreq, "Set the pxa27x maxfreq in MHz" + "(typically 624=>pxa270, 416=>pxa271, 520=>pxa272)"); + +struct pxa_cpufreq_data { + struct clk *clk_core; +}; +static struct pxa_cpufreq_data pxa_cpufreq_data; + +struct pxa_freqs { + unsigned int khz; + int vmin; + int vmax; +}; + +/* + * PXA255 definitions + */ +static const struct pxa_freqs pxa255_run_freqs[] = +{ + /* CPU MEMBUS run turbo PXbus SDRAM */ + { 99500, -1, -1}, /* 99, 99, 50, 50 */ + {132700, -1, -1}, /* 133, 133, 66, 66 */ + {199100, -1, -1}, /* 199, 199, 99, 99 */ + {265400, -1, -1}, /* 265, 265, 133, 66 */ + {331800, -1, -1}, /* 331, 331, 166, 83 */ + {398100, -1, -1}, /* 398, 398, 196, 99 */ +}; + +/* Use the turbo mode frequencies for the CPUFREQ_POLICY_POWERSAVE policy */ +static const struct pxa_freqs pxa255_turbo_freqs[] = +{ + /* CPU run turbo PXbus SDRAM */ + { 99500, -1, -1}, /* 99, 99, 50, 50 */ + {199100, -1, -1}, /* 99, 199, 50, 99 */ + {298500, -1, -1}, /* 99, 287, 50, 99 */ + {298600, -1, -1}, /* 199, 287, 99, 99 */ + {398100, -1, -1}, /* 199, 398, 99, 99 */ +}; + +#define NUM_PXA25x_RUN_FREQS ARRAY_SIZE(pxa255_run_freqs) +#define NUM_PXA25x_TURBO_FREQS ARRAY_SIZE(pxa255_turbo_freqs) + +static struct cpufreq_frequency_table + pxa255_run_freq_table[NUM_PXA25x_RUN_FREQS+1]; +static struct cpufreq_frequency_table + pxa255_turbo_freq_table[NUM_PXA25x_TURBO_FREQS+1]; + +static unsigned int pxa255_turbo_table; +module_param(pxa255_turbo_table, uint, 0); +MODULE_PARM_DESC(pxa255_turbo_table, "Selects the frequency table (0 = run table, !0 = turbo table)"); + +static struct pxa_freqs pxa27x_freqs[] = { + {104000, 900000, 1705000 }, + {156000, 1000000, 1705000 }, + {208000, 1180000, 1705000 }, + {312000, 1250000, 1705000 }, + {416000, 1350000, 1705000 }, + {520000, 1450000, 1705000 }, + {624000, 1550000, 1705000 } +}; + +#define NUM_PXA27x_FREQS ARRAY_SIZE(pxa27x_freqs) +static struct cpufreq_frequency_table + pxa27x_freq_table[NUM_PXA27x_FREQS+1]; + +#ifdef CONFIG_REGULATOR + +static int pxa_cpufreq_change_voltage(const struct pxa_freqs *pxa_freq) +{ + int ret = 0; + int vmin, vmax; + + if (!cpu_is_pxa27x()) + return 0; + + vmin = pxa_freq->vmin; + vmax = pxa_freq->vmax; + if ((vmin == -1) || (vmax == -1)) + return 0; + + ret = regulator_set_voltage(vcc_core, vmin, vmax); + if (ret) + pr_err("Failed to set vcc_core in [%dmV..%dmV]\n", vmin, vmax); + return ret; +} + +static void pxa_cpufreq_init_voltages(void) +{ + vcc_core = regulator_get(NULL, "vcc_core"); + if (IS_ERR(vcc_core)) { + pr_info("Didn't find vcc_core regulator\n"); + vcc_core = NULL; + } else { + pr_info("Found vcc_core regulator\n"); + } +} +#else +static int pxa_cpufreq_change_voltage(const struct pxa_freqs *pxa_freq) +{ + return 0; +} + +static void pxa_cpufreq_init_voltages(void) { } +#endif + +static void find_freq_tables(struct cpufreq_frequency_table **freq_table, + const struct pxa_freqs **pxa_freqs) +{ + if (cpu_is_pxa25x()) { + if (!pxa255_turbo_table) { + *pxa_freqs = pxa255_run_freqs; + *freq_table = pxa255_run_freq_table; + } else { + *pxa_freqs = pxa255_turbo_freqs; + *freq_table = pxa255_turbo_freq_table; + } + } else if (cpu_is_pxa27x()) { + *pxa_freqs = pxa27x_freqs; + *freq_table = pxa27x_freq_table; + } else { + BUG(); + } +} + +static void pxa27x_guess_max_freq(void) +{ + if (!pxa27x_maxfreq) { + pxa27x_maxfreq = 416000; + pr_info("PXA CPU 27x max frequency not defined (pxa27x_maxfreq), assuming pxa271 with %dkHz maxfreq\n", + pxa27x_maxfreq); + } else { + pxa27x_maxfreq *= 1000; + } +} + +static unsigned int pxa_cpufreq_get(unsigned int cpu) +{ + struct pxa_cpufreq_data *data = cpufreq_get_driver_data(); + + return (unsigned int) clk_get_rate(data->clk_core) / 1000; +} + +static int pxa_set_target(struct cpufreq_policy *policy, unsigned int idx) +{ + struct cpufreq_frequency_table *pxa_freqs_table; + const struct pxa_freqs *pxa_freq_settings; + struct pxa_cpufreq_data *data = cpufreq_get_driver_data(); + unsigned int new_freq_cpu; + int ret = 0; + + /* Get the current policy */ + find_freq_tables(&pxa_freqs_table, &pxa_freq_settings); + + new_freq_cpu = pxa_freq_settings[idx].khz; + + if (freq_debug) + pr_debug("Changing CPU frequency from %d Mhz to %d Mhz\n", + policy->cur / 1000, new_freq_cpu / 1000); + + if (vcc_core && new_freq_cpu > policy->cur) { + ret = pxa_cpufreq_change_voltage(&pxa_freq_settings[idx]); + if (ret) + return ret; + } + + clk_set_rate(data->clk_core, new_freq_cpu * 1000); + + /* + * Even if voltage setting fails, we don't report it, as the frequency + * change succeeded. The voltage reduction is not a critical failure, + * only power savings will suffer from this. + * + * Note: if the voltage change fails, and a return value is returned, a + * bug is triggered (seems a deadlock). Should anybody find out where, + * the "return 0" should become a "return ret". + */ + if (vcc_core && new_freq_cpu < policy->cur) + ret = pxa_cpufreq_change_voltage(&pxa_freq_settings[idx]); + + return 0; +} + +static int pxa_cpufreq_init(struct cpufreq_policy *policy) +{ + int i; + unsigned int freq; + struct cpufreq_frequency_table *pxa255_freq_table; + const struct pxa_freqs *pxa255_freqs; + + /* try to guess pxa27x cpu */ + if (cpu_is_pxa27x()) + pxa27x_guess_max_freq(); + + pxa_cpufreq_init_voltages(); + + /* set default policy and cpuinfo */ + policy->cpuinfo.transition_latency = 1000; /* FIXME: 1 ms, assumed */ + + /* Generate pxa25x the run cpufreq_frequency_table struct */ + for (i = 0; i < NUM_PXA25x_RUN_FREQS; i++) { + pxa255_run_freq_table[i].frequency = pxa255_run_freqs[i].khz; + pxa255_run_freq_table[i].driver_data = i; + } + pxa255_run_freq_table[i].frequency = CPUFREQ_TABLE_END; + + /* Generate pxa25x the turbo cpufreq_frequency_table struct */ + for (i = 0; i < NUM_PXA25x_TURBO_FREQS; i++) { + pxa255_turbo_freq_table[i].frequency = + pxa255_turbo_freqs[i].khz; + pxa255_turbo_freq_table[i].driver_data = i; + } + pxa255_turbo_freq_table[i].frequency = CPUFREQ_TABLE_END; + + pxa255_turbo_table = !!pxa255_turbo_table; + + /* Generate the pxa27x cpufreq_frequency_table struct */ + for (i = 0; i < NUM_PXA27x_FREQS; i++) { + freq = pxa27x_freqs[i].khz; + if (freq > pxa27x_maxfreq) + break; + pxa27x_freq_table[i].frequency = freq; + pxa27x_freq_table[i].driver_data = i; + } + pxa27x_freq_table[i].driver_data = i; + pxa27x_freq_table[i].frequency = CPUFREQ_TABLE_END; + + /* + * Set the policy's minimum and maximum frequencies from the tables + * just constructed. This sets cpuinfo.mxx_freq, min and max. + */ + if (cpu_is_pxa25x()) { + find_freq_tables(&pxa255_freq_table, &pxa255_freqs); + pr_info("using %s frequency table\n", + pxa255_turbo_table ? "turbo" : "run"); + + policy->freq_table = pxa255_freq_table; + } + else if (cpu_is_pxa27x()) { + policy->freq_table = pxa27x_freq_table; + } + + pr_info("frequency change support initialized\n"); + + return 0; +} + +static struct cpufreq_driver pxa_cpufreq_driver = { + .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK, + .verify = cpufreq_generic_frequency_table_verify, + .target_index = pxa_set_target, + .init = pxa_cpufreq_init, + .get = pxa_cpufreq_get, + .name = "PXA2xx", + .driver_data = &pxa_cpufreq_data, +}; + +static int __init pxa_cpu_init(void) +{ + int ret = -ENODEV; + + pxa_cpufreq_data.clk_core = clk_get_sys(NULL, "core"); + if (IS_ERR(pxa_cpufreq_data.clk_core)) + return PTR_ERR(pxa_cpufreq_data.clk_core); + + if (cpu_is_pxa25x() || cpu_is_pxa27x()) + ret = cpufreq_register_driver(&pxa_cpufreq_driver); + return ret; +} + +static void __exit pxa_cpu_exit(void) +{ + cpufreq_unregister_driver(&pxa_cpufreq_driver); +} + + +MODULE_AUTHOR("Intrinsyc Software Inc."); +MODULE_DESCRIPTION("CPU frequency changing driver for the PXA architecture"); +MODULE_LICENSE("GPL"); +module_init(pxa_cpu_init); +module_exit(pxa_cpu_exit); |