1 files changed, 178 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c/mach-osiris-dvs.c b/arch/arm/mach-s3c/mach-osiris-dvs.c
new file mode 100644
index 000000000..2e283aeda
--- /dev/null
+++ b/arch/arm/mach-s3c/mach-osiris-dvs.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2009 Simtec Electronics
+//	http://armlinux.simtec.co.uk/
+//	Ben Dooks <ben@simtec.co.uk>
+//
+// Simtec Osiris Dynamic Voltage Scaling support.
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/cpufreq.h>
+#include <linux/gpio.h>
+
+#include <linux/mfd/tps65010.h>
+
+#include <linux/soc/samsung/s3c-cpu-freq.h>
+#include "gpio-samsung.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 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 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 actually 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		= osiris_dvs_remove,
+	.driver		= {
+		.name	= "osiris-dvs",
+		.pm	= &osiris_dvs_pm,
+	},
+};
+
+module_platform_driver(osiris_dvs_driver);
+
+MODULE_DESCRIPTION("Simtec OSIRIS DVS support");
+MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:osiris-dvs");