diff options
Diffstat (limited to 'drivers/clk/samsung/clk-exynos-arm64.c')
| -rw-r--r-- | drivers/clk/samsung/clk-exynos-arm64.c | 229 |
1 files changed, 213 insertions, 16 deletions
diff --git a/drivers/clk/samsung/clk-exynos-arm64.c b/drivers/clk/samsung/clk-exynos-arm64.c index b921b9a1134a..7d8937caf22a 100644 --- a/drivers/clk/samsung/clk-exynos-arm64.c +++ b/drivers/clk/samsung/clk-exynos-arm64.c @@ -10,6 +10,9 @@ */ #include <linux/clk.h> #include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/pm_runtime.h> +#include <linux/slab.h> #include "clk-exynos-arm64.h" @@ -21,6 +24,19 @@ #define GATE_OFF_START 0x2000 #define GATE_OFF_END 0x2fff +struct exynos_arm64_cmu_data { + struct samsung_clk_reg_dump *clk_save; + unsigned int nr_clk_save; + const struct samsung_clk_reg_dump *clk_suspend; + unsigned int nr_clk_suspend; + + struct clk *clk; + struct clk **pclks; + int nr_pclks; + + struct samsung_clk_provider *ctx; +}; + /** * exynos_arm64_init_clocks - Set clocks initial configuration * @np: CMU device tree node with "reg" property (CMU addr) @@ -57,6 +73,83 @@ static void __init exynos_arm64_init_clocks(struct device_node *np, } /** + * exynos_arm64_enable_bus_clk - Enable parent clock of specified CMU + * + * @dev: Device object; may be NULL if this function is not being + * called from platform driver probe function + * @np: CMU device tree node + * @cmu: CMU data + * + * Keep CMU parent clock running (needed for CMU registers access). + * + * Return: 0 on success or a negative error code on failure. + */ +static int __init exynos_arm64_enable_bus_clk(struct device *dev, + struct device_node *np, const struct samsung_cmu_info *cmu) +{ + struct clk *parent_clk; + + if (!cmu->clk_name) + return 0; + + if (dev) { + struct exynos_arm64_cmu_data *data; + + parent_clk = clk_get(dev, cmu->clk_name); + data = dev_get_drvdata(dev); + if (data) + data->clk = parent_clk; + } else { + parent_clk = of_clk_get_by_name(np, cmu->clk_name); + } + + if (IS_ERR(parent_clk)) + return PTR_ERR(parent_clk); + + return clk_prepare_enable(parent_clk); +} + +static int __init exynos_arm64_cmu_prepare_pm(struct device *dev, + const struct samsung_cmu_info *cmu) +{ + struct exynos_arm64_cmu_data *data = dev_get_drvdata(dev); + int i; + + data->clk_save = samsung_clk_alloc_reg_dump(cmu->clk_regs, + cmu->nr_clk_regs); + if (!data->clk_save) + return -ENOMEM; + + data->nr_clk_save = cmu->nr_clk_regs; + data->clk_suspend = cmu->suspend_regs; + data->nr_clk_suspend = cmu->nr_suspend_regs; + data->nr_pclks = of_clk_get_parent_count(dev->of_node); + if (!data->nr_pclks) + return 0; + + data->pclks = devm_kcalloc(dev, sizeof(struct clk *), data->nr_pclks, + GFP_KERNEL); + if (!data->pclks) { + kfree(data->clk_save); + return -ENOMEM; + } + + for (i = 0; i < data->nr_pclks; i++) { + struct clk *clk = of_clk_get(dev->of_node, i); + + if (IS_ERR(clk)) { + kfree(data->clk_save); + while (--i >= 0) + clk_put(data->pclks[i]); + return PTR_ERR(clk); + } + data->pclks[i] = clk; + } + + return 0; +} + +/** * exynos_arm64_register_cmu - Register specified Exynos CMU domain * @dev: Device object; may be NULL if this function is not being * called from platform driver probe function @@ -72,23 +165,127 @@ static void __init exynos_arm64_init_clocks(struct device_node *np, void __init exynos_arm64_register_cmu(struct device *dev, struct device_node *np, const struct samsung_cmu_info *cmu) { - /* Keep CMU parent clock running (needed for CMU registers access) */ - if (cmu->clk_name) { - struct clk *parent_clk; - - if (dev) - parent_clk = clk_get(dev, cmu->clk_name); - else - parent_clk = of_clk_get_by_name(np, cmu->clk_name); - - if (IS_ERR(parent_clk)) { - pr_err("%s: could not find bus clock %s; err = %ld\n", - __func__, cmu->clk_name, PTR_ERR(parent_clk)); - } else { - clk_prepare_enable(parent_clk); - } - } + int err; + + /* + * Try to boot even if the parent clock enablement fails, as it might be + * already enabled by bootloader. + */ + err = exynos_arm64_enable_bus_clk(dev, np, cmu); + if (err) + pr_err("%s: could not enable bus clock %s; err = %d\n", + __func__, cmu->clk_name, err); exynos_arm64_init_clocks(np, cmu->clk_regs, cmu->nr_clk_regs); samsung_cmu_register_one(np, cmu); } + +/** + * exynos_arm64_register_cmu_pm - Register Exynos CMU domain with PM support + * + * @pdev: Platform device object + * @set_manual: If true, set gate clocks to manual mode + * + * It's a version of exynos_arm64_register_cmu() with PM support. Should be + * called from probe function of platform driver. + * + * Return: 0 on success, or negative error code on error. + */ +int __init exynos_arm64_register_cmu_pm(struct platform_device *pdev, + bool set_manual) +{ + const struct samsung_cmu_info *cmu; + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct exynos_arm64_cmu_data *data; + void __iomem *reg_base; + int ret; + + cmu = of_device_get_match_data(dev); + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + platform_set_drvdata(pdev, data); + + ret = exynos_arm64_cmu_prepare_pm(dev, cmu); + if (ret) + return ret; + + /* + * Try to boot even if the parent clock enablement fails, as it might be + * already enabled by bootloader. + */ + ret = exynos_arm64_enable_bus_clk(dev, NULL, cmu); + if (ret) + dev_err(dev, "%s: could not enable bus clock %s; err = %d\n", + __func__, cmu->clk_name, ret); + + if (set_manual) + exynos_arm64_init_clocks(np, cmu->clk_regs, cmu->nr_clk_regs); + + reg_base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(reg_base)) + return PTR_ERR(reg_base); + + data->ctx = samsung_clk_init(dev, reg_base, cmu->nr_clk_ids); + + /* + * Enable runtime PM here to allow the clock core using runtime PM + * for the registered clocks. Additionally, we increase the runtime + * PM usage count before registering the clocks, to prevent the + * clock core from runtime suspending the device. + */ + pm_runtime_get_noresume(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + + samsung_cmu_register_clocks(data->ctx, cmu); + samsung_clk_of_add_provider(dev->of_node, data->ctx); + pm_runtime_put_sync(dev); + + return 0; +} + +int exynos_arm64_cmu_suspend(struct device *dev) +{ + struct exynos_arm64_cmu_data *data = dev_get_drvdata(dev); + int i; + + samsung_clk_save(data->ctx->reg_base, data->clk_save, + data->nr_clk_save); + + for (i = 0; i < data->nr_pclks; i++) + clk_prepare_enable(data->pclks[i]); + + /* For suspend some registers have to be set to certain values */ + samsung_clk_restore(data->ctx->reg_base, data->clk_suspend, + data->nr_clk_suspend); + + for (i = 0; i < data->nr_pclks; i++) + clk_disable_unprepare(data->pclks[i]); + + clk_disable_unprepare(data->clk); + + return 0; +} + +int exynos_arm64_cmu_resume(struct device *dev) +{ + struct exynos_arm64_cmu_data *data = dev_get_drvdata(dev); + int i; + + clk_prepare_enable(data->clk); + + for (i = 0; i < data->nr_pclks; i++) + clk_prepare_enable(data->pclks[i]); + + samsung_clk_restore(data->ctx->reg_base, data->clk_save, + data->nr_clk_save); + + for (i = 0; i < data->nr_pclks; i++) + clk_disable_unprepare(data->pclks[i]); + + return 0; +} |