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 000000000000..ad2792dfbee1
--- /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");