summaryrefslogtreecommitdiffstats
path: root/drivers/cpufreq/pxa2xx-cpufreq.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/cpufreq/pxa2xx-cpufreq.c')
-rw-r--r--drivers/cpufreq/pxa2xx-cpufreq.c321
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 0000000000..ed1ae061a6
--- /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);