diff options
Diffstat (limited to 'drivers/cpufreq/ppc_cbe_cpufreq_pervasive.c')
| -rw-r--r-- | drivers/cpufreq/ppc_cbe_cpufreq_pervasive.c | 102 |
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; +} + |