On 08-06-15, 20:29, Pi-Cheng Chen wrote:

Sorry for the delay, I have been quite busy recently.

No stupid wrappers please. Doesn't make anything better.

+
+static struct mtk_cpu_dvfs_info *mtk_cpu_dvfs_info_get(int cpu)

A very bad name to a routine with very specific functionality.

+{
+	struct mtk_cpu_dvfs_info *info;
+	struct list_head *list;
+
+	list_for_each(list, &cpu_dvfs_info_list) {
+		info = to_mtk_cpu_dvfs_info(list);
+
+		if (cpumask_test_cpu(cpu, info->cpus))
+			return info;
+	}
+
+	return NULL;
+}
+
+static void mtk_cpu_dvfs_info_release(void)
+{
+	struct list_head *list, *tmp;
+	struct mtk_cpu_dvfs_info *info;
+
+	list_for_each_safe(list, tmp, &cpu_dvfs_info_list) {
+		info = to_mtk_cpu_dvfs_info(list);
+
+		dev_pm_opp_free_cpufreq_table(info->cpu_dev,
+					      &info->freq_table);
+
+		if (!IS_ERR(info->proc_reg))
+			regulator_put(info->proc_reg);
+		if (!IS_ERR(info->sram_reg))
+			regulator_put(info->sram_reg);
+		if (!IS_ERR(info->cpu_clk))
+			clk_put(info->cpu_clk);
+		if (!IS_ERR(info->inter_clk))
+			clk_put(info->inter_clk);
+
+		of_free_opp_table(info->cpu_dev);
+
+		list_del(list);
+		kfree(info);
+	}
+}
+
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#define MAX(a, b) ((a) > (b) ? (a) : (b))

Look for these in kernel.h

+static int mtk_cpufreq_set_voltage(struct mtk_cpu_dvfs_info *info, int vproc)
+{
+	if (info->need_voltage_trace)
+		return mtk_cpufreq_voltage_trace(info, vproc);
+	else
+		return regulator_set_voltage(info->proc_reg, vproc,
+					     vproc + VOLT_TOL);
+}
+
+static int mtk_cpufreq_set_target(struct cpufreq_policy *policy,
+				  unsigned int index)
+{
+	struct cpufreq_frequency_table *freq_table = policy->freq_table;
+	struct clk *cpu_clk = policy->clk;
+	struct clk *armpll = clk_get_parent(cpu_clk);
+	struct mtk_cpu_dvfs_info *info = policy->driver_data;
+	struct device *cpu_dev = info->cpu_dev;
+	struct dev_pm_opp *opp;
+	long freq_hz, old_freq_hz;
+	int vproc, old_vproc, inter_vproc, target_vproc, ret;
+
+	inter_vproc = info->intermediate_voltage;
+
+	old_freq_hz = clk_get_rate(cpu_clk);
+	old_vproc = regulator_get_voltage(info->proc_reg);
+
+	freq_hz = freq_table[index].frequency * 1000;

A blank line here.

+	rcu_read_lock();
+	opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
+	if (IS_ERR(opp)) {
+		rcu_read_unlock();
+		pr_err("cpu%d: failed to find OPP for %ld\n",
+		       policy->cpu, freq_hz);
+		return PTR_ERR(opp);
+	}
+	vproc = dev_pm_opp_get_voltage(opp);
+	rcu_read_unlock();
+
+	/*
+	 * If the new voltage or the intermediate voltage is higher than the
+	 * current voltage, scale up voltage first.
+	 */
+	target_vproc = (inter_vproc > vproc) ? inter_vproc : vproc;
+	if (old_vproc < target_vproc) {
+		ret = mtk_cpufreq_set_voltage(info, target_vproc);
+		if (ret) {
+			pr_err("cpu%d: failed to scale up voltage!\n",
+			       policy->cpu);
+			mtk_cpufreq_set_voltage(info, old_vproc);
+			return ret;
+		}
+	}
+
+	/* Reparent the CPU clock to intermediate clock. */
+	ret = clk_set_parent(cpu_clk, info->inter_clk);
+	if (ret) {
+		pr_err("cpu%d: failed to re-parent cpu clock!\n",
+		       policy->cpu);
+		mtk_cpufreq_set_voltage(info, old_vproc);
+		WARN_ON(1);
+		return ret;
+	}
+
+	/* Set the original PLL to target rate. */
+	ret = clk_set_rate(armpll, freq_hz);
+	if (ret) {
+		pr_err("cpu%d: failed to scale cpu clock rate!\n",
+		       policy->cpu);
+		clk_set_parent(cpu_clk, armpll);
+		mtk_cpufreq_set_voltage(info, old_vproc);
+		return ret;
+	}
+
+	/* Set parent of CPU clock back to the original PLL. */
+	ret = clk_set_parent(cpu_clk, armpll);
+	if (ret) {
+		pr_err("cpu%d: failed to re-parent cpu clock!\n",
+		       policy->cpu);
+		mtk_cpufreq_set_voltage(info, inter_vproc);
+		WARN_ON(1);
+		return ret;
+	}
+
+	/*
+	 * If the new voltage is lower than the intermediate voltage or the
+	 * original voltage, scale down to the new voltage.
+	 */
+	if (vproc < inter_vproc || vproc < old_vproc) {
+		ret = mtk_cpufreq_set_voltage(info, vproc);
+		if (ret) {
+			pr_err("cpu%d: failed to scale down voltage!\n",
+			       policy->cpu);
+			clk_set_parent(cpu_clk, info->inter_clk);
+			clk_set_rate(armpll, old_freq_hz);
+			clk_set_parent(cpu_clk, armpll);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int mtk_cpufreq_init(struct cpufreq_policy *policy)
+{
+	struct mtk_cpu_dvfs_info *info;
+	int ret;
+
+	info = mtk_cpu_dvfs_info_get(policy->cpu);
+	if (!info) {
+		pr_err("%s: mtk cpu dvfs info for cpu%d is not initialized\n",
+		       __func__, policy->cpu);
+		return -ENODEV;
+	}
+
+	ret = cpufreq_table_validate_and_show(policy, info->freq_table);
+	if (ret) {
+		pr_err("%s: invalid frequency table: %d\n", __func__, ret);
+		return ret;
+	}
+
+	cpumask_copy(policy->cpus, info->cpus);
+	policy->driver_data = info;
+	policy->clk = info->cpu_clk;
+
+	return 0;
+}
+
+static struct cpufreq_driver mt8173_cpufreq_driver = {
+	.flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+	.verify = cpufreq_generic_frequency_table_verify,
+	.target_index = mtk_cpufreq_set_target,
+	.get = cpufreq_generic_get,
+	.init = mtk_cpufreq_init,
+	.name = "mtk-cpufreq",
+	.attr = cpufreq_generic_attr,
+};
+
+static int mtk_cpu_dvfs_info_init(int cpu)
+{
+	struct device *cpu_dev;
+	struct regulator *proc_reg = ERR_PTR(-ENODEV);
+	struct regulator *sram_reg = ERR_PTR(-ENODEV);
+	struct clk *cpu_clk = ERR_PTR(-ENODEV);
+	struct clk *inter_clk = ERR_PTR(-ENODEV);
+	struct mtk_cpu_dvfs_info *info;
+	struct cpufreq_frequency_table *freq_table;
+	struct dev_pm_opp *opp;
+	unsigned long rate;
+	int ret;
+
+	cpu_dev = get_cpu_device(cpu);
+	if (!cpu_dev) {
+		pr_err("failed to get cpu%d device\n", cpu);
+		return -ENODEV;
+	}
+
+	ret = of_init_opp_table(cpu_dev);
+	if (ret) {
+		pr_warn("no OPP table for cpu%d\n", cpu);
+		return ret;
+	}
+
+	cpu_clk = clk_get(cpu_dev, "cpu");
+	if (IS_ERR(cpu_clk)) {
+		if (PTR_ERR(cpu_clk) == -EPROBE_DEFER)
+			pr_warn("cpu clk for cpu%d not ready, retry.\n", cpu);
+		else
+			pr_err("failed to get cpu clk for cpu%d\n", cpu);
+
+		ret = PTR_ERR(cpu_clk);
+		goto out_free_opp_table;
+	}
+
+	inter_clk = clk_get(cpu_dev, "intermediate");
+	if (IS_ERR(inter_clk)) {
+		if (PTR_ERR(inter_clk) == -EPROBE_DEFER)
+			pr_warn("intermediate clk for cpu%d not ready, retry.\n",
+				cpu);
+		else
+			pr_err("failed to get intermediate clk for cpu%d\n",
+			       cpu);
+
+		ret = PTR_ERR(cpu_clk);
+		goto out_free_resources;
+	}
+
+	proc_reg = regulator_get_exclusive(cpu_dev, "proc");
+	if (IS_ERR(proc_reg)) {
+		if (PTR_ERR(proc_reg) == -EPROBE_DEFER)
+			pr_warn("proc regulator for cpu%d not ready, retry.\n",
+				cpu);
+		else
+			pr_err("failed to get proc regulator for cpu%d\n",
+			       cpu);
+
+		ret = PTR_ERR(proc_reg);
+		goto out_free_resources;
+	}
+
+	/* Both presence and absence of sram regulator are valid cases. */
+	sram_reg = regulator_get_exclusive(cpu_dev, "sram");
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info) {
+		ret = -ENOMEM;
+		goto out_free_resources;
+	}
+
+	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
+	if (ret) {
+		pr_err("failed to init cpufreq table for cpu%d: %d\n",
+		       cpu, ret);
+		goto out_free_mtk_cpu_dvfs_info;
+	}
+
+	if (!alloc_cpumask_var(&info->cpus, GFP_KERNEL))

Why getting into such trouble? What about just saving policy's pointer
in info and use it for freq_table, cpus mask, etc ?

+		goto out_free_cpufreq_table;
+

+}
+
+static int mt8173_cpufreq_probe(struct platform_device *pdev)
+{
+	int cpu, ret;
+
+	for_each_possible_cpu(cpu) {
+		/*
+		 * If the struct mtk_cpu_dvfs_info for the cpu power domain
+		 * is already initialized, skip this CPU.
+		 */
+		if (!mtk_cpu_dvfs_info_get(cpu)) {
+			ret = mtk_cpu_dvfs_info_init(cpu);
+			if (ret) {
+				if (ret != -EPROBE_DEFER)
+					pr_err("%s probe fail\n", __func__);
+
+				mtk_cpu_dvfs_info_release();
+				return ret;
+			}
+		}
+	}
+
+	ret = cpufreq_register_driver(&mt8173_cpufreq_driver);
+	if (ret) {
+		pr_err("failed to register mtk cpufreq driver\n");
+		mtk_cpu_dvfs_info_release();
+	}
+
+	return ret;
+}
+
+static struct platform_driver mt8173_cpufreq_platdrv = {
+	.driver = {
+		.name	= "mt8173-cpufreq",
+	},
+	.probe		= mt8173_cpufreq_probe,
+};
+module_platform_driver(mt8173_cpufreq_platdrv);
+
+static int mt8173_cpufreq_driver_init(void)
+{
+	struct platform_device *pdev;
+
+	if (!of_machine_is_compatible("mediatek,mt8173"))
+		return -ENODEV;
+
+	pdev = platform_device_register_simple("mt8173-cpufreq", -1, NULL, 0);
+	if (IS_ERR(pdev)) {
+		pr_err("failed to register mtk-cpufreq platform device\n");
+		return PTR_ERR(pdev);
+	}
+
+	return 0;
+}
+module_init(mt8173_cpufreq_driver_init);

Can this driver be built as module? Why this module* crap all over the
place?

-- 
viresh