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Diffstat (limited to 'arch/arm/mach-s3c24xx/mach-osiris-dvs.c')
-rw-r--r--arch/arm/mach-s3c24xx/mach-osiris-dvs.c194
1 files changed, 194 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c24xx/mach-osiris-dvs.c b/arch/arm/mach-s3c24xx/mach-osiris-dvs.c
new file mode 100644
index 0000000..ad2792d
--- /dev/null
+++ b/arch/arm/mach-s3c24xx/mach-osiris-dvs.c
@@ -0,0 +1,194 @@
+/* linux/arch/arm/mach-s3c2440/mach-osiris-dvs.c
+ *
+ * Copyright (c) 2009 Simtec Electronics
+ * http://armlinux.simtec.co.uk/
+ * Ben Dooks <ben@simtec.co.uk>
+ *
+ * Simtec Osiris Dynamic Voltage Scaling support.
+ *
+ * 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.
+*/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/cpufreq.h>
+#include <linux/gpio.h>
+
+#include <linux/i2c/tps65010.h>
+
+#include <plat/cpu-freq.h>
+
+#define OSIRIS_GPIO_DVS S3C2410_GPB(5)
+
+static bool dvs_en;
+
+static void osiris_dvs_tps_setdvs(bool on)
+{
+ unsigned vregs1 = 0, vdcdc2 = 0;
+
+ if (!on) {
+ vdcdc2 = TPS_VCORE_DISCH | TPS_LP_COREOFF;
+ vregs1 = TPS_LDO1_OFF; /* turn off in low-power mode */
+ }
+
+ dvs_en = on;
+ vdcdc2 |= TPS_VCORE_1_3V | TPS_VCORE_LP_1_0V;
+ vregs1 |= TPS_LDO2_ENABLE | TPS_LDO1_ENABLE;
+
+ tps65010_config_vregs1(vregs1);
+ tps65010_config_vdcdc2(vdcdc2);
+}
+
+static bool is_dvs(struct s3c_freq *f)
+{
+ /* at the moment, we assume ARMCLK = HCLK => DVS */
+ return f->armclk == f->hclk;
+}
+
+/* keep track of current state */
+static bool cur_dvs = false;
+
+static int osiris_dvs_notify(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ struct cpufreq_freqs *cf = data;
+ struct s3c_cpufreq_freqs *freqs = to_s3c_cpufreq(cf);
+ bool old_dvs = is_dvs(&freqs->old);
+ bool new_dvs = is_dvs(&freqs->new);
+ int ret = 0;
+
+ if (!dvs_en)
+ return 0;
+
+ printk(KERN_DEBUG "%s: old %ld,%ld new %ld,%ld\n", __func__,
+ freqs->old.armclk, freqs->old.hclk,
+ freqs->new.armclk, freqs->new.hclk);
+
+ switch (val) {
+ case CPUFREQ_PRECHANGE:
+ if (old_dvs & !new_dvs ||
+ cur_dvs & !new_dvs) {
+ pr_debug("%s: exiting dvs\n", __func__);
+ cur_dvs = false;
+ gpio_set_value(OSIRIS_GPIO_DVS, 1);
+ }
+ break;
+ case CPUFREQ_POSTCHANGE:
+ if (!old_dvs & new_dvs ||
+ !cur_dvs & new_dvs) {
+ pr_debug("entering dvs\n");
+ cur_dvs = true;
+ gpio_set_value(OSIRIS_GPIO_DVS, 0);
+ }
+ break;
+ }
+
+ return ret;
+}
+
+static struct notifier_block osiris_dvs_nb = {
+ .notifier_call = osiris_dvs_notify,
+};
+
+static int __devinit osiris_dvs_probe(struct platform_device *pdev)
+{
+ int ret;
+
+ dev_info(&pdev->dev, "initialising\n");
+
+ ret = gpio_request(OSIRIS_GPIO_DVS, "osiris-dvs");
+ if (ret) {
+ dev_err(&pdev->dev, "cannot claim gpio\n");
+ goto err_nogpio;
+ }
+
+ /* start with dvs disabled */
+ gpio_direction_output(OSIRIS_GPIO_DVS, 1);
+
+ ret = cpufreq_register_notifier(&osiris_dvs_nb,
+ CPUFREQ_TRANSITION_NOTIFIER);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register with cpufreq\n");
+ goto err_nofreq;
+ }
+
+ osiris_dvs_tps_setdvs(true);
+
+ return 0;
+
+err_nofreq:
+ gpio_free(OSIRIS_GPIO_DVS);
+
+err_nogpio:
+ return ret;
+}
+
+static int __devexit osiris_dvs_remove(struct platform_device *pdev)
+{
+ dev_info(&pdev->dev, "exiting\n");
+
+ /* disable any current dvs */
+ gpio_set_value(OSIRIS_GPIO_DVS, 1);
+ osiris_dvs_tps_setdvs(false);
+
+ cpufreq_unregister_notifier(&osiris_dvs_nb,
+ CPUFREQ_TRANSITION_NOTIFIER);
+
+ gpio_free(OSIRIS_GPIO_DVS);
+
+ return 0;
+}
+
+/* the CONFIG_PM block is so small, it isn't worth actaully compiling it
+ * out if the configuration isn't set. */
+
+static int osiris_dvs_suspend(struct device *dev)
+{
+ gpio_set_value(OSIRIS_GPIO_DVS, 1);
+ osiris_dvs_tps_setdvs(false);
+ cur_dvs = false;
+
+ return 0;
+}
+
+static int osiris_dvs_resume(struct device *dev)
+{
+ osiris_dvs_tps_setdvs(true);
+ return 0;
+}
+
+static const struct dev_pm_ops osiris_dvs_pm = {
+ .suspend = osiris_dvs_suspend,
+ .resume = osiris_dvs_resume,
+};
+
+static struct platform_driver osiris_dvs_driver = {
+ .probe = osiris_dvs_probe,
+ .remove = __devexit_p(osiris_dvs_remove),
+ .driver = {
+ .name = "osiris-dvs",
+ .owner = THIS_MODULE,
+ .pm = &osiris_dvs_pm,
+ },
+};
+
+static int __init osiris_dvs_init(void)
+{
+ return platform_driver_register(&osiris_dvs_driver);
+}
+
+static void __exit osiris_dvs_exit(void)
+{
+ platform_driver_unregister(&osiris_dvs_driver);
+}
+
+module_init(osiris_dvs_init);
+module_exit(osiris_dvs_exit);
+
+MODULE_DESCRIPTION("Simtec OSIRIS DVS support");
+MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:osiris-dvs");