diff options
Diffstat (limited to 'drivers/clk/sunxi/clk-sun9i-mmc.c')
| -rw-r--r-- | drivers/clk/sunxi/clk-sun9i-mmc.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/drivers/clk/sunxi/clk-sun9i-mmc.c b/drivers/clk/sunxi/clk-sun9i-mmc.c new file mode 100644 index 000000000000..710c273648d7 --- /dev/null +++ b/drivers/clk/sunxi/clk-sun9i-mmc.c @@ -0,0 +1,219 @@ +/* + * Copyright 2015 Chen-Yu Tsai + * + * Chen-Yu Tsai <wens@csie.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/reset.h> +#include <linux/platform_device.h> +#include <linux/reset-controller.h> +#include <linux/spinlock.h> + +#define SUN9I_MMC_WIDTH 4 + +#define SUN9I_MMC_GATE_BIT 16 +#define SUN9I_MMC_RESET_BIT 18 + +struct sun9i_mmc_clk_data { + spinlock_t lock; + void __iomem *membase; + struct clk *clk; + struct reset_control *reset; + struct clk_onecell_data clk_data; + struct reset_controller_dev rcdev; +}; + +static int sun9i_mmc_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct sun9i_mmc_clk_data *data = container_of(rcdev, + struct sun9i_mmc_clk_data, + rcdev); + unsigned long flags; + void __iomem *reg = data->membase + SUN9I_MMC_WIDTH * id; + u32 val; + + clk_prepare_enable(data->clk); + spin_lock_irqsave(&data->lock, flags); + + val = readl(reg); + writel(val & ~BIT(SUN9I_MMC_RESET_BIT), reg); + + spin_unlock_irqrestore(&data->lock, flags); + clk_disable_unprepare(data->clk); + + return 0; +} + +static int sun9i_mmc_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct sun9i_mmc_clk_data *data = container_of(rcdev, + struct sun9i_mmc_clk_data, + rcdev); + unsigned long flags; + void __iomem *reg = data->membase + SUN9I_MMC_WIDTH * id; + u32 val; + + clk_prepare_enable(data->clk); + spin_lock_irqsave(&data->lock, flags); + + val = readl(reg); + writel(val | BIT(SUN9I_MMC_RESET_BIT), reg); + + spin_unlock_irqrestore(&data->lock, flags); + clk_disable_unprepare(data->clk); + + return 0; +} + +static struct reset_control_ops sun9i_mmc_reset_ops = { + .assert = sun9i_mmc_reset_assert, + .deassert = sun9i_mmc_reset_deassert, +}; + +static int sun9i_a80_mmc_config_clk_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct sun9i_mmc_clk_data *data; + struct clk_onecell_data *clk_data; + const char *clk_name = np->name; + const char *clk_parent; + struct resource *r; + int count, i, ret; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + spin_lock_init(&data->lock); + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + /* one clock/reset pair per word */ + count = DIV_ROUND_UP((r->end - r->start + 1), SUN9I_MMC_WIDTH); + data->membase = devm_ioremap_resource(&pdev->dev, r); + if (IS_ERR(data->membase)) + return PTR_ERR(data->membase); + + clk_data = &data->clk_data; + clk_data->clk_num = count; + clk_data->clks = devm_kcalloc(&pdev->dev, count, sizeof(struct clk *), + GFP_KERNEL); + if (!clk_data->clks) + return -ENOMEM; + + data->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(data->clk)) { + dev_err(&pdev->dev, "Could not get clock\n"); + return PTR_ERR(data->clk); + } + + data->reset = devm_reset_control_get(&pdev->dev, NULL); + if (IS_ERR(data->reset)) { + dev_err(&pdev->dev, "Could not get reset control\n"); + return PTR_ERR(data->reset); + } + + ret = reset_control_deassert(data->reset); + if (ret) { + dev_err(&pdev->dev, "Reset deassert err %d\n", ret); + return ret; + } + + clk_parent = __clk_get_name(data->clk); + for (i = 0; i < count; i++) { + of_property_read_string_index(np, "clock-output-names", + i, &clk_name); + + clk_data->clks[i] = clk_register_gate(&pdev->dev, clk_name, + clk_parent, 0, + data->membase + SUN9I_MMC_WIDTH * i, + SUN9I_MMC_GATE_BIT, 0, + &data->lock); + + if (IS_ERR(clk_data->clks[i])) { + ret = PTR_ERR(clk_data->clks[i]); + goto err_clk_register; + } + } + + ret = of_clk_add_provider(np, of_clk_src_onecell_get, clk_data); + if (ret) + goto err_clk_provider; + + data->rcdev.owner = THIS_MODULE; + data->rcdev.nr_resets = count; + data->rcdev.ops = &sun9i_mmc_reset_ops; + data->rcdev.of_node = pdev->dev.of_node; + + ret = reset_controller_register(&data->rcdev); + if (ret) + goto err_rc_reg; + + platform_set_drvdata(pdev, data); + + return 0; + +err_rc_reg: + of_clk_del_provider(np); + +err_clk_provider: + for (i = 0; i < count; i++) + clk_unregister(clk_data->clks[i]); + +err_clk_register: + reset_control_assert(data->reset); + + return ret; +} + +static int sun9i_a80_mmc_config_clk_remove(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct sun9i_mmc_clk_data *data = platform_get_drvdata(pdev); + struct clk_onecell_data *clk_data = &data->clk_data; + int i; + + reset_controller_unregister(&data->rcdev); + of_clk_del_provider(np); + for (i = 0; i < clk_data->clk_num; i++) + clk_unregister(clk_data->clks[i]); + + reset_control_assert(data->reset); + + return 0; +} + +static const struct of_device_id sun9i_a80_mmc_config_clk_dt_ids[] = { + { .compatible = "allwinner,sun9i-a80-mmc-config-clk" }, + { /* sentinel */ } +}; + +static struct platform_driver sun9i_a80_mmc_config_clk_driver = { + .driver = { + .name = "sun9i-a80-mmc-config-clk", + .of_match_table = sun9i_a80_mmc_config_clk_dt_ids, + }, + .probe = sun9i_a80_mmc_config_clk_probe, + .remove = sun9i_a80_mmc_config_clk_remove, +}; +module_platform_driver(sun9i_a80_mmc_config_clk_driver); + +MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>"); +MODULE_DESCRIPTION("Allwinner A80 MMC clock/reset Driver"); +MODULE_LICENSE("GPL v2"); |