1 files changed, 308 insertions, 0 deletions
diff --git a/drivers/cpufreq/qoriq-cpufreq.c b/drivers/cpufreq/qoriq-cpufreq.c
new file mode 100644
index 0000000000..0aecaecbb0
--- /dev/null
+++ b/drivers/cpufreq/qoriq-cpufreq.c
@@ -0,0 +1,308 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2013 Freescale Semiconductor, Inc.
+ *
+ * CPU Frequency Scaling driver for Freescale QorIQ SoCs.
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/cpufreq.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/platform_device.h>
+
+/**
+ * struct cpu_data
+ * @pclk: the parent clock of cpu
+ * @table: frequency table
+ */
+struct cpu_data {
+	struct clk **pclk;
+	struct cpufreq_frequency_table *table;
+};
+
+/**
+ * struct soc_data - SoC specific data
+ * @flags: SOC_xxx
+ */
+struct soc_data {
+	u32 flags;
+};
+
+static u32 get_bus_freq(void)
+{
+	struct device_node *soc;
+	u32 sysfreq;
+	struct clk *pltclk;
+	int ret;
+
+	/* get platform freq by searching bus-frequency property */
+	soc = of_find_node_by_type(NULL, "soc");
+	if (soc) {
+		ret = of_property_read_u32(soc, "bus-frequency", &sysfreq);
+		of_node_put(soc);
+		if (!ret)
+			return sysfreq;
+	}
+
+	/* get platform freq by its clock name */
+	pltclk = clk_get(NULL, "cg-pll0-div1");
+	if (IS_ERR(pltclk)) {
+		pr_err("%s: can't get bus frequency %ld\n",
+		       __func__, PTR_ERR(pltclk));
+		return PTR_ERR(pltclk);
+	}
+
+	return clk_get_rate(pltclk);
+}
+
+static struct clk *cpu_to_clk(int cpu)
+{
+	struct device_node *np;
+	struct clk *clk;
+
+	if (!cpu_present(cpu))
+		return NULL;
+
+	np = of_get_cpu_node(cpu, NULL);
+	if (!np)
+		return NULL;
+
+	clk = of_clk_get(np, 0);
+	of_node_put(np);
+	return clk;
+}
+
+/* traverse cpu nodes to get cpu mask of sharing clock wire */
+static void set_affected_cpus(struct cpufreq_policy *policy)
+{
+	struct cpumask *dstp = policy->cpus;
+	struct clk *clk;
+	int i;
+
+	for_each_present_cpu(i) {
+		clk = cpu_to_clk(i);
+		if (IS_ERR(clk)) {
+			pr_err("%s: no clock for cpu %d\n", __func__, i);
+			continue;
+		}
+
+		if (clk_is_match(policy->clk, clk))
+			cpumask_set_cpu(i, dstp);
+	}
+}
+
+/* reduce the duplicated frequencies in frequency table */
+static void freq_table_redup(struct cpufreq_frequency_table *freq_table,
+		int count)
+{
+	int i, j;
+
+	for (i = 1; i < count; i++) {
+		for (j = 0; j < i; j++) {
+			if (freq_table[j].frequency == CPUFREQ_ENTRY_INVALID ||
+					freq_table[j].frequency !=
+					freq_table[i].frequency)
+				continue;
+
+			freq_table[i].frequency = CPUFREQ_ENTRY_INVALID;
+			break;
+		}
+	}
+}
+
+/* sort the frequencies in frequency table in descenting order */
+static void freq_table_sort(struct cpufreq_frequency_table *freq_table,
+		int count)
+{
+	int i, j, ind;
+	unsigned int freq, max_freq;
+	struct cpufreq_frequency_table table;
+
+	for (i = 0; i < count - 1; i++) {
+		max_freq = freq_table[i].frequency;
+		ind = i;
+		for (j = i + 1; j < count; j++) {
+			freq = freq_table[j].frequency;
+			if (freq == CPUFREQ_ENTRY_INVALID ||
+					freq <= max_freq)
+				continue;
+			ind = j;
+			max_freq = freq;
+		}
+
+		if (ind != i) {
+			/* exchange the frequencies */
+			table.driver_data = freq_table[i].driver_data;
+			table.frequency = freq_table[i].frequency;
+			freq_table[i].driver_data = freq_table[ind].driver_data;
+			freq_table[i].frequency = freq_table[ind].frequency;
+			freq_table[ind].driver_data = table.driver_data;
+			freq_table[ind].frequency = table.frequency;
+		}
+	}
+}
+
+static int qoriq_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+	struct device_node *np;
+	int i, count;
+	u32 freq;
+	struct clk *clk;
+	const struct clk_hw *hwclk;
+	struct cpufreq_frequency_table *table;
+	struct cpu_data *data;
+	unsigned int cpu = policy->cpu;
+	u64 u64temp;
+
+	np = of_get_cpu_node(cpu, NULL);
+	if (!np)
+		return -ENODEV;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		goto err_np;
+
+	policy->clk = of_clk_get(np, 0);
+	if (IS_ERR(policy->clk)) {
+		pr_err("%s: no clock information\n", __func__);
+		goto err_nomem2;
+	}
+
+	hwclk = __clk_get_hw(policy->clk);
+	count = clk_hw_get_num_parents(hwclk);
+
+	data->pclk = kcalloc(count, sizeof(struct clk *), GFP_KERNEL);
+	if (!data->pclk)
+		goto err_nomem2;
+
+	table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL);
+	if (!table)
+		goto err_pclk;
+
+	for (i = 0; i < count; i++) {
+		clk = clk_hw_get_parent_by_index(hwclk, i)->clk;
+		data->pclk[i] = clk;
+		freq = clk_get_rate(clk);
+		table[i].frequency = freq / 1000;
+		table[i].driver_data = i;
+	}
+	freq_table_redup(table, count);
+	freq_table_sort(table, count);
+	table[i].frequency = CPUFREQ_TABLE_END;
+	policy->freq_table = table;
+	data->table = table;
+
+	/* update ->cpus if we have cluster, no harm if not */
+	set_affected_cpus(policy);
+	policy->driver_data = data;
+
+	/* Minimum transition latency is 12 platform clocks */
+	u64temp = 12ULL * NSEC_PER_SEC;
+	do_div(u64temp, get_bus_freq());
+	policy->cpuinfo.transition_latency = u64temp + 1;
+
+	of_node_put(np);
+
+	return 0;
+
+err_pclk:
+	kfree(data->pclk);
+err_nomem2:
+	kfree(data);
+err_np:
+	of_node_put(np);
+
+	return -ENODEV;
+}
+
+static int qoriq_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+	struct cpu_data *data = policy->driver_data;
+
+	kfree(data->pclk);
+	kfree(data->table);
+	kfree(data);
+	policy->driver_data = NULL;
+
+	return 0;
+}
+
+static int qoriq_cpufreq_target(struct cpufreq_policy *policy,
+		unsigned int index)
+{
+	struct clk *parent;
+	struct cpu_data *data = policy->driver_data;
+
+	parent = data->pclk[data->table[index].driver_data];
+	return clk_set_parent(policy->clk, parent);
+}
+
+static struct cpufreq_driver qoriq_cpufreq_driver = {
+	.name		= "qoriq_cpufreq",
+	.flags		= CPUFREQ_CONST_LOOPS |
+			  CPUFREQ_IS_COOLING_DEV,
+	.init		= qoriq_cpufreq_cpu_init,
+	.exit		= qoriq_cpufreq_cpu_exit,
+	.verify		= cpufreq_generic_frequency_table_verify,
+	.target_index	= qoriq_cpufreq_target,
+	.get		= cpufreq_generic_get,
+	.attr		= cpufreq_generic_attr,
+};
+
+static const struct of_device_id qoriq_cpufreq_blacklist[] = {
+	/* e6500 cannot use cpufreq due to erratum A-008083 */
+	{ .compatible = "fsl,b4420-clockgen", },
+	{ .compatible = "fsl,b4860-clockgen", },
+	{ .compatible = "fsl,t2080-clockgen", },
+	{ .compatible = "fsl,t4240-clockgen", },
+	{}
+};
+
+static int qoriq_cpufreq_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct device_node *np;
+
+	np = of_find_matching_node(NULL, qoriq_cpufreq_blacklist);
+	if (np) {
+		of_node_put(np);
+		dev_info(&pdev->dev, "Disabling due to erratum A-008083");
+		return -ENODEV;
+	}
+
+	ret = cpufreq_register_driver(&qoriq_cpufreq_driver);
+	if (ret)
+		return ret;
+
+	dev_info(&pdev->dev, "Freescale QorIQ CPU frequency scaling driver\n");
+	return 0;
+}
+
+static void qoriq_cpufreq_remove(struct platform_device *pdev)
+{
+	cpufreq_unregister_driver(&qoriq_cpufreq_driver);
+}
+
+static struct platform_driver qoriq_cpufreq_platform_driver = {
+	.driver = {
+		.name = "qoriq-cpufreq",
+	},
+	.probe = qoriq_cpufreq_probe,
+	.remove_new = qoriq_cpufreq_remove,
+};
+module_platform_driver(qoriq_cpufreq_platform_driver);
+
+MODULE_ALIAS("platform:qoriq-cpufreq");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>");
+MODULE_DESCRIPTION("cpufreq driver for Freescale QorIQ series SoCs");