cpufreq: tegra20: Wrap cpufreq into platform driver

Currently tegra20-cpufreq kernel module isn't getting autoloaded because
there is no device associated with the module, this is one of two patches
that resolves the module autoloading. This patch adds a module alias that
will associate the tegra20-cpufreq kernel module with the platform device,
other patch will instantiate the actual platform device. And now it makes
sense to wrap cpufreq driver into a platform driver for consistency.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/tegra20-cpufreq.c b/drivers/cpufreq/tegra20-cpufreq.c
index 7b425eb..05f57dc 100644 (file)
--- a/drivers/cpufreq/tegra20-cpufreq.c
+++ b/drivers/cpufreq/tegra20-cpufreq.c
@@ -21,7 +21,7 @@
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/of.h>
+#include <linux/platform_device.h>
 #include <linux/types.h>
 
 static struct cpufreq_frequency_table freq_table[] = {
@@ -36,15 +36,20 @@ static struct cpufreq_frequency_table freq_table[] = {
        { .frequency = CPUFREQ_TABLE_END },
 };
 
-static struct clk *cpu_clk;
-static struct clk *pll_x_clk;
-static struct clk *pll_p_clk;
-static bool pll_x_prepared;
+struct tegra20_cpufreq {
+       struct device *dev;
+       struct cpufreq_driver driver;
+       struct clk *cpu_clk;
+       struct clk *pll_x_clk;
+       struct clk *pll_p_clk;
+       bool pll_x_prepared;
+};
 
 static unsigned int tegra_get_intermediate(struct cpufreq_policy *policy,
                                           unsigned int index)
 {
-       unsigned int ifreq = clk_get_rate(pll_p_clk) / 1000;
+       struct tegra20_cpufreq *cpufreq = cpufreq_get_driver_data();
+       unsigned int ifreq = clk_get_rate(cpufreq->pll_p_clk) / 1000;
 
        /*
         * Don't switch to intermediate freq if:
@@ -60,6 +65,7 @@ static unsigned int tegra_get_intermediate(struct cpufreq_policy *policy,
 static int tegra_target_intermediate(struct cpufreq_policy *policy,
                                     unsigned int index)
 {
+       struct tegra20_cpufreq *cpufreq = cpufreq_get_driver_data();
        int ret;
 
        /*
@@ -72,21 +78,22 @@ static int tegra_target_intermediate(struct cpufreq_policy *policy,
         * Also, we wouldn't be using pll_x anymore and must not take extra
         * reference to it, as it can be disabled now to save some power.
         */
-       clk_prepare_enable(pll_x_clk);
+       clk_prepare_enable(cpufreq->pll_x_clk);
 
-       ret = clk_set_parent(cpu_clk, pll_p_clk);
+       ret = clk_set_parent(cpufreq->cpu_clk, cpufreq->pll_p_clk);
        if (ret)
-               clk_disable_unprepare(pll_x_clk);
+               clk_disable_unprepare(cpufreq->pll_x_clk);
        else
-               pll_x_prepared = true;
+               cpufreq->pll_x_prepared = true;
 
        return ret;
 }
 
 static int tegra_target(struct cpufreq_policy *policy, unsigned int index)
 {
+       struct tegra20_cpufreq *cpufreq = cpufreq_get_driver_data();
        unsigned long rate = freq_table[index].frequency;
-       unsigned int ifreq = clk_get_rate(pll_p_clk) / 1000;
+       unsigned int ifreq = clk_get_rate(cpufreq->pll_p_clk) / 1000;
        int ret;
 
        /*
@@ -94,14 +101,14 @@ static int tegra_target(struct cpufreq_policy *policy, unsigned int index)
         * as it isn't used anymore.
         */
        if (rate == ifreq)
-               return clk_set_parent(cpu_clk, pll_p_clk);
+               return clk_set_parent(cpufreq->cpu_clk, cpufreq->pll_p_clk);
 
-       ret = clk_set_rate(pll_x_clk, rate * 1000);
+       ret = clk_set_rate(cpufreq->pll_x_clk, rate * 1000);
        /* Restore to earlier frequency on error, i.e. pll_x */
        if (ret)
-               pr_err("Failed to change pll_x to %lu\n", rate);
+               dev_err(cpufreq->dev, "Failed to change pll_x to %lu\n", rate);
 
-       ret = clk_set_parent(cpu_clk, pll_x_clk);
+       ret = clk_set_parent(cpufreq->cpu_clk, cpufreq->pll_x_clk);
        /* This shouldn't fail while changing or restoring */
        WARN_ON(ret);
 
@@ -109,9 +116,9 @@ static int tegra_target(struct cpufreq_policy *policy, unsigned int index)
         * Drop count to pll_x clock only if we switched to intermediate freq
         * earlier while transitioning to a target frequency.
         */
-       if (pll_x_prepared) {
-               clk_disable_unprepare(pll_x_clk);
-               pll_x_prepared = false;
+       if (cpufreq->pll_x_prepared) {
+               clk_disable_unprepare(cpufreq->pll_x_clk);
+               cpufreq->pll_x_prepared = false;
        }
 
        return ret;
@@ -119,91 +126,111 @@ static int tegra_target(struct cpufreq_policy *policy, unsigned int index)
 
 static int tegra_cpu_init(struct cpufreq_policy *policy)
 {
+       struct tegra20_cpufreq *cpufreq = cpufreq_get_driver_data();
        int ret;
 
-       clk_prepare_enable(cpu_clk);
+       clk_prepare_enable(cpufreq->cpu_clk);
 
        /* FIXME: what's the actual transition time? */
        ret = cpufreq_generic_init(policy, freq_table, 300 * 1000);
        if (ret) {
-               clk_disable_unprepare(cpu_clk);
+               clk_disable_unprepare(cpufreq->cpu_clk);
                return ret;
        }
 
-       policy->clk = cpu_clk;
+       policy->clk = cpufreq->cpu_clk;
        policy->suspend_freq = freq_table[0].frequency;
        return 0;
 }
 
 static int tegra_cpu_exit(struct cpufreq_policy *policy)
 {
-       clk_disable_unprepare(cpu_clk);
+       struct tegra20_cpufreq *cpufreq = cpufreq_get_driver_data();
+
+       clk_disable_unprepare(cpufreq->cpu_clk);
        return 0;
 }
 
-static struct cpufreq_driver tegra_cpufreq_driver = {
-       .flags                  = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
-       .verify                 = cpufreq_generic_frequency_table_verify,
-       .get_intermediate       = tegra_get_intermediate,
-       .target_intermediate    = tegra_target_intermediate,
-       .target_index           = tegra_target,
-       .get                    = cpufreq_generic_get,
-       .init                   = tegra_cpu_init,
-       .exit                   = tegra_cpu_exit,
-       .name                   = "tegra",
-       .attr                   = cpufreq_generic_attr,
-       .suspend                = cpufreq_generic_suspend,
-};
-
-static int __init tegra_cpufreq_init(void)
+static int tegra20_cpufreq_probe(struct platform_device *pdev)
 {
+       struct tegra20_cpufreq *cpufreq;
        int err;
 
-       if (!of_machine_is_compatible("nvidia,tegra20"))
-               return -ENODEV;
+       cpufreq = devm_kzalloc(&pdev->dev, sizeof(*cpufreq), GFP_KERNEL);
+       if (!cpufreq)
+               return -ENOMEM;
 
-       cpu_clk = clk_get_sys(NULL, "cclk");
-       if (IS_ERR(cpu_clk))
-               return PTR_ERR(cpu_clk);
+       cpufreq->cpu_clk = clk_get_sys(NULL, "cclk");
+       if (IS_ERR(cpufreq->cpu_clk))
+               return PTR_ERR(cpufreq->cpu_clk);
 
-       pll_x_clk = clk_get_sys(NULL, "pll_x");
-       if (IS_ERR(pll_x_clk)) {
-               err = PTR_ERR(pll_x_clk);
+       cpufreq->pll_x_clk = clk_get_sys(NULL, "pll_x");
+       if (IS_ERR(cpufreq->pll_x_clk)) {
+               err = PTR_ERR(cpufreq->pll_x_clk);
                goto put_cpu;
        }
 
-       pll_p_clk = clk_get_sys(NULL, "pll_p");
-       if (IS_ERR(pll_p_clk)) {
-               err = PTR_ERR(pll_p_clk);
+       cpufreq->pll_p_clk = clk_get_sys(NULL, "pll_p");
+       if (IS_ERR(cpufreq->pll_p_clk)) {
+               err = PTR_ERR(cpufreq->pll_p_clk);
                goto put_pll_x;
        }
 
-       err = cpufreq_register_driver(&tegra_cpufreq_driver);
+       cpufreq->dev = &pdev->dev;
+       cpufreq->driver.get = cpufreq_generic_get;
+       cpufreq->driver.attr = cpufreq_generic_attr;
+       cpufreq->driver.init = tegra_cpu_init;
+       cpufreq->driver.exit = tegra_cpu_exit;
+       cpufreq->driver.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK;
+       cpufreq->driver.verify = cpufreq_generic_frequency_table_verify;
+       cpufreq->driver.suspend = cpufreq_generic_suspend;
+       cpufreq->driver.driver_data = cpufreq;
+       cpufreq->driver.target_index = tegra_target;
+       cpufreq->driver.get_intermediate = tegra_get_intermediate;
+       cpufreq->driver.target_intermediate = tegra_target_intermediate;
+       snprintf(cpufreq->driver.name, CPUFREQ_NAME_LEN, "tegra");
+
+       err = cpufreq_register_driver(&cpufreq->driver);
        if (err)
                goto put_pll_p;
 
+       platform_set_drvdata(pdev, cpufreq);
+
        return 0;
 
 put_pll_p:
-       clk_put(pll_p_clk);
+       clk_put(cpufreq->pll_p_clk);
 put_pll_x:
-       clk_put(pll_x_clk);
+       clk_put(cpufreq->pll_x_clk);
 put_cpu:
-       clk_put(cpu_clk);
+       clk_put(cpufreq->cpu_clk);
 
        return err;
 }
 
-static void __exit tegra_cpufreq_exit(void)
+static int tegra20_cpufreq_remove(struct platform_device *pdev)
 {
-       cpufreq_unregister_driver(&tegra_cpufreq_driver);
-       clk_put(pll_p_clk);
-       clk_put(pll_x_clk);
-       clk_put(cpu_clk);
+       struct tegra20_cpufreq *cpufreq = platform_get_drvdata(pdev);
+
+       cpufreq_unregister_driver(&cpufreq->driver);
+
+       clk_put(cpufreq->pll_p_clk);
+       clk_put(cpufreq->pll_x_clk);
+       clk_put(cpufreq->cpu_clk);
+
+       return 0;
 }
 
+static struct platform_driver tegra20_cpufreq_driver = {
+       .probe          = tegra20_cpufreq_probe,
+       .remove         = tegra20_cpufreq_remove,
+       .driver         = {
+               .name   = "tegra20-cpufreq",
+       },
+};
+module_platform_driver(tegra20_cpufreq_driver);
+
+MODULE_ALIAS("platform:tegra20-cpufreq");
 MODULE_AUTHOR("Colin Cross <ccross@android.com>");
 MODULE_DESCRIPTION("NVIDIA Tegra20 cpufreq driver");
 MODULE_LICENSE("GPL");
-module_init(tegra_cpufreq_init);
-module_exit(tegra_cpufreq_exit);