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// SPDX-License-Identifier: GPL-2.0
/*
* Freescale SAI BCLK as a generic clock driver
*
* Copyright 2020 Michael Walle <michael@walle.cc>
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#define I2S_CSR 0x00
#define I2S_CR2 0x08
#define CSR_BCE_BIT 28
#define CR2_BCD BIT(24)
#define CR2_DIV_SHIFT 0
#define CR2_DIV_WIDTH 8
struct fsl_sai_clk {
struct clk_divider div;
struct clk_gate gate;
spinlock_t lock;
};
static int fsl_sai_clk_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct fsl_sai_clk *sai_clk;
struct clk_parent_data pdata = { .index = 0 };
void __iomem *base;
struct clk_hw *hw;
struct resource *res;
sai_clk = devm_kzalloc(dev, sizeof(*sai_clk), GFP_KERNEL);
if (!sai_clk)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
spin_lock_init(&sai_clk->lock);
sai_clk->gate.reg = base + I2S_CSR;
sai_clk->gate.bit_idx = CSR_BCE_BIT;
sai_clk->gate.lock = &sai_clk->lock;
sai_clk->div.reg = base + I2S_CR2;
sai_clk->div.shift = CR2_DIV_SHIFT;
sai_clk->div.width = CR2_DIV_WIDTH;
sai_clk->div.lock = &sai_clk->lock;
/* set clock direction, we are the BCLK master */
writel(CR2_BCD, base + I2S_CR2);
hw = clk_hw_register_composite_pdata(dev, dev->of_node->name,
&pdata, 1, NULL, NULL,
&sai_clk->div.hw,
&clk_divider_ops,
&sai_clk->gate.hw,
&clk_gate_ops,
CLK_SET_RATE_GATE);
if (IS_ERR(hw))
return PTR_ERR(hw);
platform_set_drvdata(pdev, hw);
return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, hw);
}
static int fsl_sai_clk_remove(struct platform_device *pdev)
{
struct clk_hw *hw = platform_get_drvdata(pdev);
clk_hw_unregister_composite(hw);
return 0;
}
static const struct of_device_id of_fsl_sai_clk_ids[] = {
{ .compatible = "fsl,vf610-sai-clock" },
{ }
};
MODULE_DEVICE_TABLE(of, of_fsl_sai_clk_ids);
static struct platform_driver fsl_sai_clk_driver = {
.probe = fsl_sai_clk_probe,
.remove = fsl_sai_clk_remove,
.driver = {
.name = "fsl-sai-clk",
.of_match_table = of_fsl_sai_clk_ids,
},
};
module_platform_driver(fsl_sai_clk_driver);
MODULE_DESCRIPTION("Freescale SAI bitclock-as-a-clock driver");
MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:fsl-sai-clk");