From d2f31f1da54f83c4eb2738402284c49cd51798d1 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Thu, 28 Aug 2014 11:22:28 +0530 Subject: [PATCH] cpufreq: cpu0: Move per-cluster initialization code to ->init() Currently this driver only support platforms on which all CPUs share clock & voltage lines and there is requirement to support platforms which have separate clock & voltage lines for CPUs, like Qualcomm's Krait and ARM's big LITTLE. Each group of CPUs sharing clock/voltage lines are represented by 'struct cpufreq_policy' in cpufreq framework. And core calls ->init() once for each policy. Currently we do all initialization/allocation from probe() which wouldn't work for above scenario. To make it work for these platforms, the first step is to move all initialization/allocation to ->init() and add ->exit() to do the reverse of it. Also, remove all global variables and allocate space for them at runtime. This patch creates 'struct private_data' for keeping all such information and a pointer to that would be stored in policy->driver_data. The changed probe() routine now tries to see if regulator/clocks are available or we need to defer probe. In case they are available, it registers cpufreq driver. Otherwise, returns with -EPROBE_DEFER. We still *don't* support platforms with separate clock/voltage lines for CPUs. This would be done in a separate patch later. Tested-by: Stephen Boyd Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cpufreq-cpu0.c | 191 +++++++++++++++++++++++---------- 1 file changed, 137 insertions(+), 54 deletions(-) diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c index 741ff220f9bf..03e352b627dd 100644 --- a/drivers/cpufreq/cpufreq-cpu0.c +++ b/drivers/cpufreq/cpufreq-cpu0.c @@ -28,18 +28,21 @@ #include #include -static unsigned int transition_latency; -static unsigned int voltage_tolerance; /* in percentage */ - -static struct device *cpu_dev; -static struct clk *cpu_clk; -static struct regulator *cpu_reg; -static struct cpufreq_frequency_table *freq_table; -static struct thermal_cooling_device *cdev; +struct private_data { + struct device *cpu_dev; + struct regulator *cpu_reg; + struct thermal_cooling_device *cdev; + unsigned int voltage_tolerance; /* in percentage */ +}; static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index) { struct dev_pm_opp *opp; + struct cpufreq_frequency_table *freq_table = policy->freq_table; + struct clk *cpu_clk = policy->clk; + struct private_data *priv = policy->driver_data; + struct device *cpu_dev = priv->cpu_dev; + struct regulator *cpu_reg = priv->cpu_reg; unsigned long volt = 0, volt_old = 0, tol = 0; unsigned int old_freq, new_freq; long freq_Hz, freq_exact; @@ -64,7 +67,7 @@ static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index) } volt = dev_pm_opp_get_voltage(opp); rcu_read_unlock(); - tol = volt * voltage_tolerance / 100; + tol = volt * priv->voltage_tolerance / 100; volt_old = regulator_get_voltage(cpu_reg); } @@ -103,26 +106,13 @@ static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index) return ret; } -static int cpu0_cpufreq_init(struct cpufreq_policy *policy) +static int allocate_resources(struct device **cdev, + struct regulator **creg, struct clk **cclk) { - policy->clk = cpu_clk; - return cpufreq_generic_init(policy, freq_table, transition_latency); -} - -static struct cpufreq_driver cpu0_cpufreq_driver = { - .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK, - .verify = cpufreq_generic_frequency_table_verify, - .target_index = cpu0_set_target, - .get = cpufreq_generic_get, - .init = cpu0_cpufreq_init, - .name = "generic_cpu0", - .attr = cpufreq_generic_attr, -}; - -static int cpu0_cpufreq_probe(struct platform_device *pdev) -{ - struct device_node *np; - int ret; + struct device *cpu_dev; + struct regulator *cpu_reg; + struct clk *cpu_clk; + int ret = 0; cpu_dev = get_cpu_device(0); if (!cpu_dev) { @@ -130,12 +120,6 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev) return -ENODEV; } - np = of_node_get(cpu_dev->of_node); - if (!np) { - dev_err(cpu_dev, "failed to find cpu0 node\n"); - return -ENOENT; - } - cpu_reg = regulator_get_optional(cpu_dev, "cpu0"); if (IS_ERR(cpu_reg)) { /* @@ -144,8 +128,7 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev) */ if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) { dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n"); - ret = -EPROBE_DEFER; - goto out_put_node; + return -EPROBE_DEFER; } dev_warn(cpu_dev, "failed to get cpu0 regulator: %ld\n", PTR_ERR(cpu_reg)); @@ -153,6 +136,10 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev) cpu_clk = clk_get(cpu_dev, NULL); if (IS_ERR(cpu_clk)) { + /* put regulator */ + if (!IS_ERR(cpu_reg)) + regulator_put(cpu_reg); + ret = PTR_ERR(cpu_clk); /* @@ -163,8 +150,39 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev) dev_dbg(cpu_dev, "cpu0 clock not ready, retry\n"); else dev_err(cpu_dev, "failed to get cpu0 clock: %d\n", ret); + } else { + *cdev = cpu_dev; + *creg = cpu_reg; + *cclk = cpu_clk; + } - goto out_put_reg; + return ret; +} + +static int cpu0_cpufreq_init(struct cpufreq_policy *policy) +{ + struct cpufreq_frequency_table *freq_table; + struct thermal_cooling_device *cdev; + struct device_node *np; + struct private_data *priv; + struct device *cpu_dev; + struct regulator *cpu_reg; + struct clk *cpu_clk; + unsigned int transition_latency; + int ret; + + /* We only support cpu0 currently */ + ret = allocate_resources(&cpu_dev, &cpu_reg, &cpu_clk); + if (ret) { + pr_err("%s: Failed to allocate resources\n: %d", __func__, ret); + return ret; + } + + np = of_node_get(cpu_dev->of_node); + if (!np) { + dev_err(cpu_dev, "failed to find cpu%d node\n", policy->cpu); + ret = -ENOENT; + goto out_put_reg_clk; } /* OPPs might be populated at runtime, don't check for error here */ @@ -173,10 +191,16 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev) ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); if (ret) { dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); - goto out_put_clk; + goto out_put_node; } - of_property_read_u32(np, "voltage-tolerance", &voltage_tolerance); + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) { + ret = -ENOMEM; + goto out_free_table; + } + + of_property_read_u32(np, "voltage-tolerance", &priv->voltage_tolerance); if (of_property_read_u32(np, "clock-latency", &transition_latency)) transition_latency = CPUFREQ_ETERNAL; @@ -206,12 +230,6 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev) transition_latency += ret * 1000; } - ret = cpufreq_register_driver(&cpu0_cpufreq_driver); - if (ret) { - dev_err(cpu_dev, "failed to register driver: %d\n", ret); - goto out_free_table; - } - /* * For now, just loading the cooling device; * thermal DT code takes care of matching them. @@ -222,29 +240,94 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev) dev_err(cpu_dev, "running cpufreq without cooling device: %ld\n", PTR_ERR(cdev)); + else + priv->cdev = cdev; } - of_node_put(np); + + priv->cpu_dev = cpu_dev; + priv->cpu_reg = cpu_reg; + policy->driver_data = priv; + + policy->clk = cpu_clk; + ret = cpufreq_generic_init(policy, freq_table, transition_latency); + if (ret) + goto out_cooling_unregister; + return 0; +out_cooling_unregister: + cpufreq_cooling_unregister(priv->cdev); + kfree(priv); out_free_table: dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); -out_put_clk: - clk_put(cpu_clk); -out_put_reg: - if (!IS_ERR(cpu_reg)) - regulator_put(cpu_reg); out_put_node: of_node_put(np); +out_put_reg_clk: + clk_put(cpu_clk); + if (!IS_ERR(cpu_reg)) + regulator_put(cpu_reg); + + return ret; +} + +static int cpu0_cpufreq_exit(struct cpufreq_policy *policy) +{ + struct private_data *priv = policy->driver_data; + + cpufreq_cooling_unregister(priv->cdev); + dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); + clk_put(policy->clk); + if (!IS_ERR(priv->cpu_reg)) + regulator_put(priv->cpu_reg); + kfree(priv); + + return 0; +} + +static struct cpufreq_driver cpu0_cpufreq_driver = { + .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK, + .verify = cpufreq_generic_frequency_table_verify, + .target_index = cpu0_set_target, + .get = cpufreq_generic_get, + .init = cpu0_cpufreq_init, + .exit = cpu0_cpufreq_exit, + .name = "generic_cpu0", + .attr = cpufreq_generic_attr, +}; + +static int cpu0_cpufreq_probe(struct platform_device *pdev) +{ + struct device *cpu_dev; + struct regulator *cpu_reg; + struct clk *cpu_clk; + int ret; + + /* + * All per-cluster (CPUs sharing clock/voltages) initialization is done + * from ->init(). In probe(), we just need to make sure that clk and + * regulators are available. Else defer probe and retry. + * + * FIXME: Is checking this only for CPU0 sufficient ? + */ + ret = allocate_resources(&cpu_dev, &cpu_reg, &cpu_clk); + if (ret) + return ret; + + clk_put(cpu_clk); + if (!IS_ERR(cpu_reg)) + regulator_put(cpu_reg); + + ret = cpufreq_register_driver(&cpu0_cpufreq_driver); + if (ret) + dev_err(cpu_dev, "failed register driver: %d\n", ret); + return ret; } static int cpu0_cpufreq_remove(struct platform_device *pdev) { - cpufreq_cooling_unregister(cdev); cpufreq_unregister_driver(&cpu0_cpufreq_driver); - dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); - return 0; }