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106 lines
2.2 KiB
106 lines
2.2 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (C) 2014 Free Electrons |
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* |
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* Author: Boris BREZILLON <[email protected]> |
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* |
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* Allwinner A31 AR100 clock driver |
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*/ |
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#include <linux/bitops.h> |
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#include <linux/clk-provider.h> |
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#include <linux/init.h> |
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#include <linux/of.h> |
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#include <linux/platform_device.h> |
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#include <linux/spinlock.h> |
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#include "clk-factors.h" |
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/** |
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* sun6i_get_ar100_factors - Calculates factors p, m for AR100 |
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* |
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* AR100 rate is calculated as follows |
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* rate = (parent_rate >> p) / (m + 1); |
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*/ |
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static void sun6i_get_ar100_factors(struct factors_request *req) |
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{ |
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unsigned long div; |
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int shift; |
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/* clock only divides */ |
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if (req->rate > req->parent_rate) |
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req->rate = req->parent_rate; |
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div = DIV_ROUND_UP(req->parent_rate, req->rate); |
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if (div < 32) |
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shift = 0; |
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else if (div >> 1 < 32) |
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shift = 1; |
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else if (div >> 2 < 32) |
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shift = 2; |
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else |
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shift = 3; |
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div >>= shift; |
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if (div > 32) |
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div = 32; |
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req->rate = (req->parent_rate >> shift) / div; |
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req->m = div - 1; |
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req->p = shift; |
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} |
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static const struct clk_factors_config sun6i_ar100_config = { |
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.mwidth = 5, |
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.mshift = 8, |
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.pwidth = 2, |
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.pshift = 4, |
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}; |
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static const struct factors_data sun6i_ar100_data = { |
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.mux = 16, |
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.muxmask = GENMASK(1, 0), |
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.table = &sun6i_ar100_config, |
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.getter = sun6i_get_ar100_factors, |
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}; |
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static DEFINE_SPINLOCK(sun6i_ar100_lock); |
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static int sun6i_a31_ar100_clk_probe(struct platform_device *pdev) |
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{ |
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struct device_node *np = pdev->dev.of_node; |
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struct resource *r; |
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void __iomem *reg; |
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struct clk *clk; |
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r = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
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reg = devm_ioremap_resource(&pdev->dev, r); |
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if (IS_ERR(reg)) |
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return PTR_ERR(reg); |
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clk = sunxi_factors_register(np, &sun6i_ar100_data, &sun6i_ar100_lock, |
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reg); |
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if (!clk) |
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return -ENOMEM; |
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platform_set_drvdata(pdev, clk); |
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return 0; |
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} |
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static const struct of_device_id sun6i_a31_ar100_clk_dt_ids[] = { |
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{ .compatible = "allwinner,sun6i-a31-ar100-clk" }, |
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{ /* sentinel */ } |
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}; |
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static struct platform_driver sun6i_a31_ar100_clk_driver = { |
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.driver = { |
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.name = "sun6i-a31-ar100-clk", |
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.of_match_table = sun6i_a31_ar100_clk_dt_ids, |
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.suppress_bind_attrs = true, |
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}, |
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.probe = sun6i_a31_ar100_clk_probe, |
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}; |
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builtin_platform_driver(sun6i_a31_ar100_clk_driver);
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