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Diffstat (limited to 'arch/blackfin/mach-common/dpmc.c')
-rw-r--r--arch/blackfin/mach-common/dpmc.c137
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/blackfin/mach-common/dpmc.c b/arch/blackfin/mach-common/dpmc.c
new file mode 100644
index 00000000000..02c7efd1bcf
--- /dev/null
+++ b/arch/blackfin/mach-common/dpmc.c
@@ -0,0 +1,137 @@
+/*
+ * Copyright 2008 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/cpufreq.h>
+
+#include <asm/delay.h>
+#include <asm/dpmc.h>
+
+#define DRIVER_NAME "bfin dpmc"
+
+#define dprintk(msg...) \
+ cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, DRIVER_NAME, msg)
+
+struct bfin_dpmc_platform_data *pdata;
+
+/**
+ * bfin_set_vlev - Update VLEV field in VR_CTL Reg.
+ * Avoid BYPASS sequence
+ */
+static void bfin_set_vlev(unsigned int vlev)
+{
+ unsigned pll_lcnt;
+
+ pll_lcnt = bfin_read_PLL_LOCKCNT();
+
+ bfin_write_PLL_LOCKCNT(1);
+ bfin_write_VR_CTL((bfin_read_VR_CTL() & ~VLEV) | vlev);
+ bfin_write_PLL_LOCKCNT(pll_lcnt);
+}
+
+/**
+ * bfin_get_vlev - Get CPU specific VLEV from platform device data
+ */
+static unsigned int bfin_get_vlev(unsigned int freq)
+{
+ int i;
+
+ if (!pdata)
+ goto err_out;
+
+ freq >>= 16;
+
+ for (i = 0; i < pdata->tabsize; i++)
+ if (freq <= (pdata->tuple_tab[i] & 0xFFFF))
+ return pdata->tuple_tab[i] >> 16;
+
+err_out:
+ printk(KERN_WARNING "DPMC: No suitable CCLK VDDINT voltage pair found\n");
+ return VLEV_120;
+}
+
+#ifdef CONFIG_CPU_FREQ
+static int
+vreg_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
+{
+ struct cpufreq_freqs *freq = data;
+
+ if (val == CPUFREQ_PRECHANGE && freq->old < freq->new) {
+ bfin_set_vlev(bfin_get_vlev(freq->new));
+ udelay(pdata->vr_settling_time); /* Wait until Volatge settled */
+
+ } else if (val == CPUFREQ_POSTCHANGE && freq->old > freq->new)
+ bfin_set_vlev(bfin_get_vlev(freq->new));
+
+ return 0;
+}
+
+static struct notifier_block vreg_cpufreq_notifier_block = {
+ .notifier_call = vreg_cpufreq_notifier
+};
+#endif /* CONFIG_CPU_FREQ */
+
+/**
+ * bfin_dpmc_probe -
+ *
+ */
+static int __devinit bfin_dpmc_probe(struct platform_device *pdev)
+{
+ if (pdev->dev.platform_data)
+ pdata = pdev->dev.platform_data;
+ else
+ return -EINVAL;
+
+ return cpufreq_register_notifier(&vreg_cpufreq_notifier_block,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+/**
+ * bfin_dpmc_remove -
+ */
+static int __devexit bfin_dpmc_remove(struct platform_device *pdev)
+{
+ pdata = NULL;
+ return cpufreq_unregister_notifier(&vreg_cpufreq_notifier_block,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+struct platform_driver bfin_dpmc_device_driver = {
+ .probe = bfin_dpmc_probe,
+ .remove = __devexit_p(bfin_dpmc_remove),
+ .driver = {
+ .name = DRIVER_NAME,
+ }
+};
+
+/**
+ * bfin_dpmc_init - Init driver
+ */
+static int __init bfin_dpmc_init(void)
+{
+ return platform_driver_register(&bfin_dpmc_device_driver);
+}
+module_init(bfin_dpmc_init);
+
+/**
+ * bfin_dpmc_exit - break down driver
+ */
+static void __exit bfin_dpmc_exit(void)
+{
+ platform_driver_unregister(&bfin_dpmc_device_driver);
+}
+module_exit(bfin_dpmc_exit);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("cpu power management driver for Blackfin");
+MODULE_LICENSE("GPL");