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/*
* 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.h>
#include <linux/clk-provider.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/slab.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 */ }
};
MODULE_DEVICE_TABLE(of, sun9i_a80_mmc_config_clk_dt_ids);
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");
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