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Diffstat (limited to 'drivers/cpufreq/ppc_cbe_cpufreq_pervasive.c')
-rw-r--r--drivers/cpufreq/ppc_cbe_cpufreq_pervasive.c102
1 files changed, 102 insertions, 0 deletions
diff --git a/drivers/cpufreq/ppc_cbe_cpufreq_pervasive.c b/drivers/cpufreq/ppc_cbe_cpufreq_pervasive.c
new file mode 100644
index 000000000..04830cd95
--- /dev/null
+++ b/drivers/cpufreq/ppc_cbe_cpufreq_pervasive.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * pervasive backend for the cbe_cpufreq driver
+ *
+ * This driver makes use of the pervasive unit to
+ * engage the desired frequency.
+ *
+ * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
+ *
+ * Author: Christian Krafft <krafft@de.ibm.com>
+ */
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/time.h>
+#include <asm/machdep.h>
+#include <asm/hw_irq.h>
+#include <asm/cell-regs.h>
+
+#include "ppc_cbe_cpufreq.h"
+
+/* to write to MIC register */
+static u64 MIC_Slow_Fast_Timer_table[] = {
+ [0 ... 7] = 0x007fc00000000000ull,
+};
+
+/* more values for the MIC */
+static u64 MIC_Slow_Next_Timer_table[] = {
+ 0x0000240000000000ull,
+ 0x0000268000000000ull,
+ 0x000029C000000000ull,
+ 0x00002D0000000000ull,
+ 0x0000300000000000ull,
+ 0x0000334000000000ull,
+ 0x000039C000000000ull,
+ 0x00003FC000000000ull,
+};
+
+
+int cbe_cpufreq_set_pmode(int cpu, unsigned int pmode)
+{
+ struct cbe_pmd_regs __iomem *pmd_regs;
+ struct cbe_mic_tm_regs __iomem *mic_tm_regs;
+ unsigned long flags;
+ u64 value;
+#ifdef DEBUG
+ long time;
+#endif
+
+ local_irq_save(flags);
+
+ mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu);
+ pmd_regs = cbe_get_cpu_pmd_regs(cpu);
+
+#ifdef DEBUG
+ time = jiffies;
+#endif
+
+ out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]);
+ out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]);
+
+ out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]);
+ out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]);
+
+ value = in_be64(&pmd_regs->pmcr);
+ /* set bits to zero */
+ value &= 0xFFFFFFFFFFFFFFF8ull;
+ /* set bits to next pmode */
+ value |= pmode;
+
+ out_be64(&pmd_regs->pmcr, value);
+
+#ifdef DEBUG
+ /* wait until new pmode appears in status register */
+ value = in_be64(&pmd_regs->pmsr) & 0x07;
+ while (value != pmode) {
+ cpu_relax();
+ value = in_be64(&pmd_regs->pmsr) & 0x07;
+ }
+
+ time = jiffies - time;
+ time = jiffies_to_msecs(time);
+ pr_debug("had to wait %lu ms for a transition using " \
+ "pervasive unit\n", time);
+#endif
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+
+int cbe_cpufreq_get_pmode(int cpu)
+{
+ int ret;
+ struct cbe_pmd_regs __iomem *pmd_regs;
+
+ pmd_regs = cbe_get_cpu_pmd_regs(cpu);
+ ret = in_be64(&pmd_regs->pmsr) & 0x07;
+
+ return ret;
+}
+