powerpc/mpc85xx: move the cpufreq driver to drivers/cpufreq/

Change-Id: I83eb8533d747a5da8c06df54398db1a43b22fe4b
Signed-off-by: Zhao Chenhui <chenhui.zhao@freescale.com>
Reviewed-on: http://git.am.freescale.net:8181/8744
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Reviewed-by: Yang Li <LeoLi@freescale.com>
Reviewed-by: Jose Rivera <German.Rivera@freescale.com>

2 files changed, 406 insertions, 0 deletions

diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 7494565..7cf1b21 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -83,6 +83,7 @@ ppc-cbe-cpufreq-y			+= ppc_cbe_cpufreq_pervasive.o ppc_cbe_cpufreq.o
 obj-$(CONFIG_CPU_FREQ_CBE_PMI)		+= ppc_cbe_cpufreq_pmi.o
 obj-$(CONFIG_CPU_FREQ_MAPLE)		+= maple-cpufreq.o
 obj-$(CONFIG_PPC_CORENET_CPUFREQ)   += ppc-corenet-cpufreq.o
+obj-$(CONFIG_MPC85xx_CPUFREQ)		+= mpc85xx-cpufreq.o
 obj-$(CONFIG_CPU_FREQ_PMAC)		+= pmac32-cpufreq.o
 obj-$(CONFIG_CPU_FREQ_PMAC64)		+= pmac64-cpufreq.o
 obj-$(CONFIG_PPC_PASEMI_CPUFREQ)	+= pasemi-cpufreq.o
diff --git a/drivers/cpufreq/mpc85xx-cpufreq.c b/drivers/cpufreq/mpc85xx-cpufreq.c
new file mode 100644
index 0000000..ef31a9a
--- /dev/null
+++ b/drivers/cpufreq/mpc85xx-cpufreq.c
@@ -0,0 +1,405 @@
+/*
+ * Copyright (C) 2008-2012 Freescale Semiconductor, Inc.
+ * Author: Dave Liu <daveliu@freescale.com>
+ * Modifier: Chenhui Zhao <chenhui.zhao@freescale.com>
+ *
+ * The cpufreq driver is for Freescale 85xx processor,
+ * based on arch/powerpc/platforms/cell/cbe_cpufreq.c
+ * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
+ *	Christian Krafft <krafft@de.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/cpufreq.h>
+#include <linux/of_platform.h>
+#include <linux/suspend.h>
+#include <linux/cpu.h>
+#include <linux/time.h>
+#include <linux/io.h>
+#include <linux/smp.h>
+
+#include <asm/prom.h>
+#include <asm/reg.h>
+#include <asm/machdep.h>
+
+#include <sysdev/fsl_soc.h>
+
+static DEFINE_MUTEX(mpc85xx_switch_mutex);
+static void __iomem *guts;
+
+static u32 sysfreq;
+static unsigned int max_pll[2];
+static atomic_t in_jog_process;
+static struct cpufreq_frequency_table *mpc85xx_freqs;
+static int (*set_pll)(unsigned int cpu, unsigned int pll);
+
+static struct cpufreq_frequency_table mpc8536_freqs_table[] = {
+	{3,	0},
+	{4,	0},
+	{5,	0},
+	{6,	0},
+	{7,	0},
+	{8,	0},
+	{0,	CPUFREQ_TABLE_END},
+};
+
+static struct cpufreq_frequency_table p1022_freqs_table[] = {
+	{2,	0},
+	{3,	0},
+	{4,	0},
+	{5,	0},
+	{6,	0},
+	{7,	0},
+	{8,	0},
+	{0,	CPUFREQ_TABLE_END},
+};
+
+#define FREQ_500MHz	500000000
+#define FREQ_800MHz	800000000
+
+#define CORE_RATIO_STRIDE	8
+#define CORE_RATIO_MASK		0x3f
+#define CORE_RATIO_SHIFT	16
+
+#define PORPLLSR	0x0	/* Power-On Reset PLL ratio status register */
+
+#define PMJCR		0x7c	/* Power Management Jog Control Register */
+#define PMJCR_CORE0_SPD	0x00001000
+#define PMJCR_CORE_SPD	0x00002000
+
+#define POWMGTCSR	0x80 /* Power management control and status register */
+#define POWMGTCSR_JOG		0x00200000
+#define POWMGTCSR_INT_MASK	0x00000f00
+
+static void spin_while_jogging(void *dummy)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	atomic_inc(&in_jog_process);
+
+	while (atomic_read(&in_jog_process) != 0)
+		barrier();
+
+	local_irq_restore(flags);
+}
+
+static int get_pll(int hw_cpu)
+{
+	int shift;
+	u32 val = in_be32(guts + PORPLLSR);
+
+	shift = hw_cpu * CORE_RATIO_STRIDE + CORE_RATIO_SHIFT;
+
+	return (val >> shift) & CORE_RATIO_MASK;
+}
+
+static int mpc8536_set_pll(unsigned int cpu, unsigned int pll)
+{
+	u32 corefreq, val, mask;
+	unsigned int cur_pll = get_pll(0);
+	unsigned long flags;
+
+	if (pll == cur_pll)
+		return 0;
+
+	val = (pll & CORE_RATIO_MASK) << CORE_RATIO_SHIFT;
+
+	corefreq = sysfreq * pll / 2;
+	/*
+	 * Set the COREx_SPD bit if the requested core frequency
+	 * is larger than the threshold frequency.
+	 */
+	if (corefreq > FREQ_800MHz)
+			val |= PMJCR_CORE_SPD;
+
+	mask = (CORE_RATIO_MASK << CORE_RATIO_SHIFT) | PMJCR_CORE_SPD;
+	clrsetbits_be32(guts + PMJCR, mask, val);
+
+	/* readback to sync write */
+	in_be32(guts + PMJCR);
+
+	local_irq_save(flags);
+	mpc85xx_enter_jog(get_immrbase(), POWMGTCSR_JOG);
+	local_irq_restore(flags);
+
+	/* verify */
+	cur_pll =  get_pll(0);
+	if (cur_pll != pll) {
+		pr_err("%s: error. The current PLL of core 0 is %d instead of %d.\n",
+				__func__, cur_pll, pll);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int p1022_set_pll(unsigned int cpu, unsigned int pll)
+{
+	int index, hw_cpu = get_hard_smp_processor_id(cpu);
+	int shift;
+	u32 corefreq, val, mask = 0;
+	unsigned int cur_pll = get_pll(hw_cpu);
+	unsigned long flags;
+	int ret = 0;
+
+	if (pll == cur_pll)
+		return 0;
+
+	shift = hw_cpu * CORE_RATIO_STRIDE + CORE_RATIO_SHIFT;
+	val = (pll & CORE_RATIO_MASK) << shift;
+
+	corefreq = sysfreq * pll / 2;
+	/*
+	 * Set the COREx_SPD bit if the requested core frequency
+	 * is larger than the threshold frequency.
+	 */
+	if (corefreq > FREQ_500MHz)
+		val |= PMJCR_CORE0_SPD << hw_cpu;
+
+	mask = (CORE_RATIO_MASK << shift) | (PMJCR_CORE0_SPD << hw_cpu);
+	clrsetbits_be32(guts + PMJCR, mask, val);
+
+	/* readback to sync write */
+	in_be32(guts + PMJCR);
+
+	cpu_hotplug_disable();
+	/*
+	 * A Jog request can not be asserted when any core is in a low
+	 * power state on P1022. Before executing a jog request, any
+	 * core which is in a low power state must be waked by a
+	 * interrupt, and keep waking up until the sequence is
+	 * finished.
+	 */
+	for_each_present_cpu(index) {
+		if (!cpu_online(index)) {
+			cpu_hotplug_enable();
+			pr_err("%s: error, core%d is down.\n", __func__, index);
+			return -1;
+		}
+	}
+
+	atomic_set(&in_jog_process, 0);
+	smp_call_function(spin_while_jogging, NULL, 0);
+
+	local_irq_save(flags);
+
+	/* Wait for the other core to wake. */
+	if (!spin_event_timeout(atomic_read(&in_jog_process) == 1, 1000, 100)) {
+		pr_err("%s: timeout, the other core is not at running state.\n",
+					__func__);
+		ret = -1;
+		goto err;
+	}
+
+	out_be32(guts + POWMGTCSR, POWMGTCSR_JOG | POWMGTCSR_INT_MASK);
+
+	if (!spin_event_timeout(
+		(in_be32(guts + POWMGTCSR) & POWMGTCSR_JOG) == 0, 1000, 100)) {
+		pr_err("%s: timeout, fail to switch the core frequency.\n",
+				__func__);
+		ret = -1;
+		goto err;
+	}
+
+	clrbits32(guts + POWMGTCSR, POWMGTCSR_INT_MASK);
+	in_be32(guts + POWMGTCSR);
+
+	atomic_set(&in_jog_process, 0);
+err:
+	local_irq_restore(flags);
+	cpu_hotplug_enable();
+
+	/* verify */
+	cur_pll =  get_pll(hw_cpu);
+	if (cur_pll != pll) {
+		pr_err("%s: error, the current PLL of core %d is %d instead of %d.\n",
+				__func__, hw_cpu, cur_pll, pll);
+		return -1;
+	}
+
+	return ret;
+}
+
+/*
+ * cpufreq functions
+ */
+static int mpc85xx_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+	unsigned int i, cur_pll;
+	int hw_cpu = get_hard_smp_processor_id(policy->cpu);
+
+	if (!cpu_present(policy->cpu))
+		return -ENODEV;
+
+	/* the latency of a transition, the unit is ns */
+	policy->cpuinfo.transition_latency = 2000;
+
+	cur_pll = get_pll(hw_cpu);
+
+	/* initialize frequency table */
+	pr_debug("core%d frequency table:\n", hw_cpu);
+	for (i = 0; mpc85xx_freqs[i].frequency != CPUFREQ_TABLE_END; i++) {
+		if (mpc85xx_freqs[i].driver_data <= max_pll[hw_cpu]) {
+			/* The frequency unit is kHz. */
+			mpc85xx_freqs[i].frequency =
+			  (sysfreq * mpc85xx_freqs[i].driver_data / 2) / 1000;
+		} else {
+			mpc85xx_freqs[i].frequency = CPUFREQ_ENTRY_INVALID;
+		}
+
+		pr_debug("%d: %dkHz\n", i, mpc85xx_freqs[i].frequency);
+
+		if (mpc85xx_freqs[i].driver_data == cur_pll)
+			policy->cur = mpc85xx_freqs[i].frequency;
+	}
+	pr_debug("current pll is at %d, and core freq is%d\n",
+			cur_pll, policy->cur);
+
+	cpufreq_frequency_table_get_attr(mpc85xx_freqs, policy->cpu);
+
+	/*
+	 * This ensures that policy->cpuinfo_min
+	 * and policy->cpuinfo_max are set correctly.
+	 */
+	return cpufreq_frequency_table_cpuinfo(policy, mpc85xx_freqs);
+}
+
+static int mpc85xx_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+	cpufreq_frequency_table_put_attr(policy->cpu);
+
+	return 0;
+}
+
+static int mpc85xx_cpufreq_verify(struct cpufreq_policy *policy)
+{
+	return cpufreq_frequency_table_verify(policy, mpc85xx_freqs);
+}
+
+static int mpc85xx_cpufreq_target(struct cpufreq_policy *policy,
+			      unsigned int target_freq,
+			      unsigned int relation)
+{
+	struct cpufreq_freqs freqs;
+	unsigned int new;
+	int ret = 0;
+
+	if (!set_pll)
+		return -ENODEV;
+
+	cpufreq_frequency_table_target(policy,
+				       mpc85xx_freqs,
+				       target_freq,
+				       relation,
+				       &new);
+
+	freqs.old = policy->cur;
+	freqs.new = mpc85xx_freqs[new].frequency;
+	freqs.cpu = policy->cpu;
+
+	mutex_lock(&mpc85xx_switch_mutex);
+	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+
+	ret = set_pll(policy->cpu, mpc85xx_freqs[new].driver_data);
+	if (!ret) {
+		pr_info("cpufreq: Setting core%d frequency to %d kHz and PLL ratio to %d:2\n",
+			 policy->cpu, mpc85xx_freqs[new].frequency,
+			 mpc85xx_freqs[new].driver_data);
+
+		ppc_proc_freq = freqs.new * 1000ul;
+	}
+	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
+	mutex_unlock(&mpc85xx_switch_mutex);
+
+	return ret;
+}
+
+static struct cpufreq_driver mpc85xx_cpufreq_driver = {
+	.verify		= mpc85xx_cpufreq_verify,
+	.target		= mpc85xx_cpufreq_target,
+	.init		= mpc85xx_cpufreq_cpu_init,
+	.exit		= mpc85xx_cpufreq_cpu_exit,
+	.name		= "mpc85xx-JOG",
+	.flags		= CPUFREQ_CONST_LOOPS,
+};
+
+static int mpc85xx_job_probe(struct platform_device *ofdev)
+{
+	struct device_node *np = ofdev->dev.of_node;
+	unsigned int svr;
+
+	if (of_device_is_compatible(np, "fsl,mpc8536-guts")) {
+		svr = mfspr(SPRN_SVR);
+		if ((svr & 0x7fff) == 0x10) {
+			pr_err("MPC8536 Rev 1.0 do not support JOG.\n");
+			return -ENODEV;
+		}
+		mpc85xx_freqs = mpc8536_freqs_table;
+		set_pll = mpc8536_set_pll;
+	} else if (of_device_is_compatible(np, "fsl,p1022-guts")) {
+		mpc85xx_freqs = p1022_freqs_table;
+		set_pll = p1022_set_pll;
+	} else {
+		return -ENODEV;
+	}
+
+	sysfreq = fsl_get_sys_freq();
+
+	guts = of_iomap(np, 0);
+	if (!guts)
+		return -ENODEV;
+
+	max_pll[0] = get_pll(0);
+	if (mpc85xx_freqs == p1022_freqs_table)
+		max_pll[1] = get_pll(1);
+
+	pr_info("Freescale MPC85xx CPU frequency switching(JOG) driver\n");
+
+	return cpufreq_register_driver(&mpc85xx_cpufreq_driver);
+}
+
+static int mpc85xx_jog_remove(struct platform_device *ofdev)
+{
+	iounmap(guts);
+	cpufreq_unregister_driver(&mpc85xx_cpufreq_driver);
+
+	return 0;
+}
+
+static struct of_device_id mpc85xx_jog_ids[] = {
+	{ .compatible = "fsl,mpc8536-guts", },
+	{ .compatible = "fsl,p1022-guts", },
+	{}
+};
+
+static struct platform_driver mpc85xx_jog_driver = {
+	.driver = {
+		.name = "mpc85xx_cpufreq_jog",
+		.of_match_table = mpc85xx_jog_ids,
+	},
+	.probe = mpc85xx_job_probe,
+	.remove = mpc85xx_jog_remove,
+};
+
+static int __init mpc85xx_jog_init(void)
+{
+	return platform_driver_register(&mpc85xx_jog_driver);
+}
+
+static void __exit mpc85xx_jog_exit(void)
+{
+	platform_driver_unregister(&mpc85xx_jog_driver);
+}
+
+module_init(mpc85xx_jog_init);
+module_exit(mpc85xx_jog_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Dave Liu <daveliu@freescale.com>");